JP2008009409A - Display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-visibility display device with an anti-reflection function that can further reduce reflection of external light, and a method for manufacturing such a display device. <P>SOLUTION: The display device including an anti-reflective film of the present invention includes a plurality of projections on its surface. External light is reflected to not a viewer side but another adjacent projection because an interface of each projection is not flat. In other words, the number of times of incidence of external light entering the display device on the anti-reflection film is increased; therefore, the amount of external light transmitted through the anti-reflection film is increased. Thus, the amount of external light reflected to a viewed side is reduced, and the cause of a reduction in visibility such as reflection can be eliminated. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a display device having an antireflection function.

In a display device having various displays (liquid crystal display, electroluminescence (hereinafter also referred to as “EL” display, plasma display, etc.), the display screen becomes difficult to see due to reflection of the scenery due to the surface reflection of external light. Visibility may be reduced. This becomes a particularly significant problem when the display device is enlarged or used outdoors.

In order to prevent such reflection of external light, a method of providing an antireflection film on a display screen of a display device is performed. For example, as an antireflection film, there is a method in which layers having different refractive indexes are laminated so as to be effective for a wide wavelength range of visible light to form a multilayer structure (see, for example, Patent Document 1). By adopting a multilayer structure, the external light reflected at the interface between the layers to be laminated interferes with each other to cancel each other, thereby obtaining an antireflection effect.
JP 2003-248102 A

However, in the multilayer structure as described above, the light that cannot be canceled out of the external light reflected at the layer interface is radiated to the viewer side as reflected light. In order for external light to cancel each other, it is necessary to precisely control the optical characteristics and film thickness of the material of the laminated film, and antireflection treatment is applied to all external light incident from various angles. It was difficult.

In view of the above, the functions of the conventional antireflection film are limited, and an antireflection film having a higher antireflection function and a display device having such an antireflection function are demanded.

An object of the present invention is to provide a display device having an anti-reflection function capable of further reducing reflection of external light and having excellent visibility, and a method for manufacturing such a display device.

The present invention is characterized in that, in a display device, an antireflection film having a plurality of convex portions is used as an antireflection film having an antireflection function for preventing reflection of external light on the display screen surface. The convex portion of the antireflection film of the present invention is preferably conical, and the angle between the bottom surface and the side surface of the convex portion is preferably 84 degrees or more and less than 90 degrees. In addition to the conical shape, the convex portion may have a needle shape, a trapezoidal shape in which the tip of the cone is flat, or a dome shape with a rounded tip.

In the antireflection film of the present invention, the ratio of the diameter and height of the bottom surface of the convex portion is 1: 5 to 29, preferably 1:10, and the height is preferably 1 μm or more and 3 μm or less. With this size, the translucency is not lowered and the processing is relatively easy.

The present invention can also be used for a display device that is a device having a display function. The display device using the present invention includes an organic substance, an inorganic substance, and an organic substance that emits light called electroluminescence (hereinafter also referred to as “EL”). Alternatively, there are a light-emitting display device in which a light-emitting element in which a layer containing a mixture of an organic substance and an inorganic substance is interposed between electrodes and a TFT are connected, and a liquid crystal display device in which a liquid crystal element having a liquid crystal material is used as a display element. In the present invention, a display device refers to a device having a display element (such as a liquid crystal element or a light emitting element). Note that a display panel body in which a plurality of pixels including a display element such as a liquid crystal element or an EL element and a peripheral driver circuit for driving these pixels are formed over a substrate may be used. Furthermore, a device to which a flexible printed circuit (FPC) or a printed wiring board (PWB) is attached (such as an IC, a resistor, a capacitor, an inductor, or a transistor) may also be included. Furthermore, an optical sheet such as a polarizing plate or a retardation plate may be included. Furthermore, a backlight (which may include a light guide plate, a prism sheet, a diffusion sheet, a reflection sheet, or a light source (such as an LED or a cold cathode tube)) may be included.

Note that the display element and the display device can have various forms or have various elements. For example, EL elements (organic EL elements, inorganic EL elements or EL elements containing organic and inorganic substances), electron-emitting elements, liquid crystal elements, electronic ink, grating light valves (GLV), plasma display panels (PDP), digital micromirror devices (DMD), a piezoelectric ceramic display, a carbon nanotube, or the like can be applied to a display medium whose contrast is changed by an electromagnetic action. Note that a display device using an EL element is an EL display, and a display device using an electron-emitting device is a liquid crystal display such as a field emission display (FED) or a SED type flat display (SED: Surface-conduction Electron-Emitter Display). A display device using the element includes a liquid crystal display, a transmissive liquid crystal display, a transflective liquid crystal display, a reflective liquid crystal display, and a display device using electronic ink includes electronic paper.

In one embodiment of the display device of the present invention, an antireflection film having a plurality of convex portions is provided on a display screen, and the angle between the bottom surface of the convex portions and the slope is not less than 84 degrees and less than 90 degrees.

One embodiment of a display device of the present invention includes a pair of substrates, a display element provided between the pair of substrates, and at least one of the pair of substrates is a light-transmitting substrate, and a plurality of the display devices are provided outside the light-transmitting substrate. The angle between the bottom surface of the convex portion and the slope is not less than 84 degrees and less than 90 degrees.

One embodiment of a display device of the present invention includes a pair of translucent substrates, a display element provided between the pair of translucent substrates, and a pair of convex portions on the outer sides of the pair of translucent substrates. The angle between the bottom surface of the convex portion and the slope is not less than 84 degrees and less than 90 degrees.

The convex part may have a conical shape, a needle shape, a trapezoidal shape with a flat tip at the tip of the cone, or a dome shape with a rounded tip. Further, the antireflection film can be formed of a material whose refractive index changes from the surface toward the display screen instead of a uniform refractive index. For example, in the plurality of convex portions, the convex portion surface side is formed of a material having a refractive index equivalent to that of air, and has a structure that reduces reflection of the convex surface of external light incident on the convex portion more than air. On the other hand, a plurality of convex portions are formed of a material having a refractive index equivalent to that of the substrate as they approach the substrate side on the display screen side, and travel through the convex portions, and at the interface between the convex portions of light incident on the substrate and the substrate. To reduce the reflection of light.

When a glass substrate is used as the substrate, the refractive index of air is smaller than that of the glass substrate, so that the convex portion is formed of a material having a lower refractive index on the surface (the tip portion if conical), and the bottom surface of the convex portion The refractive index may be increased from the conical tip portion toward the bottom surface as it is made of a material having a high refractive index as it approaches. When glass is used for the substrate, the convex portion can be formed using a film containing fluoride, oxide, or nitride.

The display device having the antireflection film of the present invention has a plurality of convex portions on the surface, and the reflected light of the outside light is not reflected on the viewing side because the convex portion interface is not flat, and is adjacent to other convex portions. Reflect on. Or it progresses between convex parts. The incident external light is partially transmitted through the convex portion, and the reflected light is incident on the adjacent convex portion again. Thus, the external light reflected by the convex interface repeatedly enters the other adjacent convex part.

That is, the number of external light incident on the display device that is incident on the antireflection film increases, so that the amount of light transmitted through the antireflection film increases. Therefore, the external light reflected on the viewer side is reduced, and the cause of lower visibility such as reflection can be prevented.

INDUSTRIAL APPLICABILITY The present invention can provide a display device with high visibility having a high antireflection function that can reduce reflection of external light by providing an antireflection film having a plurality of convex portions on the surface. Therefore, a display device with higher image quality and higher performance can be manufactured.

Embodiments of the present invention will be described below with reference to the drawings. However, the present invention can be implemented in many different modes, and those skilled in the art can easily understand that the modes and details can be variously changed without departing from the spirit and scope of the present invention. Is done. Therefore, the present invention is not construed as being limited to the description of this embodiment mode. Note that in all the drawings for describing the embodiments, the same portions or portions having similar functions are denoted by the same reference numerals, and repetitive description thereof is omitted.

(Embodiment 1)
In this embodiment, an example of a display device that has an antireflection function that can reduce reflection of external light and has excellent visibility will be described.

The present invention is characterized in that, in a display device, an antireflection film having a plurality of convex portions is used as an antireflection film having an antireflection function for preventing reflection of external light on the display screen surface. The convex portion of the antireflection film of the present invention is preferably conical, and the angle between the bottom surface and the side surface of the convex portion is preferably 84 degrees or more and less than 90 degrees.

FIG. 1 shows a top view and a cross-sectional view of the antireflection film of the present invention. In FIG. 1, a plurality of convex portions 451 are provided on the display screen of the display device 450. 1A is a top view of the display device of this embodiment mode, and FIG. 1B is a cross-sectional view taken along line AB in FIG. 1A. FIG. 1C is an enlarged view of FIG. As shown in FIGS. 1A and 1B, the convex portion 451 is provided adjacent to the display screen.

As shown in FIG. 1C, in the antireflection film of the present invention, the ratio of the diameter L to the height H of the bottom surface of the convex portion 451 is 1: 5 or more (1:29 or less), preferably 1:10, The height H is preferably 1 μm or more and 3 μm. With this size, the translucency is not lowered and the processing is relatively easy.

Moreover, in the convex part of this invention, as shown in FIG.1 (C), as for the angle (theta) which the bottom face and slope of the convex part which are protrusions make, 84 degrees or more and less than 90 degrees are preferable. When the convex portion has the above angle, the external light is repeatedly reflected and transmitted to the plural convex portions, so that the transmittance of the external light to the convex portion is improved and the reflectance to the viewing side can be reduced. it can.

Since the convex portion is provided on the display screen surface of the display device 450, the bottom surface of the convex portion and the display screen surface of the display device 450 are parallel to each other. Therefore, the preferable angle formed by the oblique side of the convex portion and the display screen surface is similarly preferably 84 degrees or more and less than 90 degrees, and more preferably 87 degrees or more and less than 90 degrees.

In addition to the conical shape, the convex portion may have a needle shape, a trapezoidal shape in which the tip of the cone is flat, or a dome shape with a rounded tip. Examples of the shape of the convex portions are shown in FIGS. FIG. 2A shows a shape having a top surface and a bottom surface, not a conical shape like a point. Therefore, the cross-sectional view in the plane perpendicular to the bottom surface has a trapezoidal shape. In the convex portion 461 provided on the display device 460 as shown in FIG. 2A, the height from the lower bottom surface to the upper bottom surface is defined as a height H in the present invention.

FIG. 2B illustrates an example in which a convex portion 471 having a round tip is provided over the display device 470. Thus, the convex part may have a shape with a rounded tip and a curvature. In this case, the height H of the convex part is set to the highest position of the tip part from the bottom surface.

FIG. 2C illustrates an example in which a convex portion 481 having a plurality of angles θ1 and θ2 is provided over the display device 480. As described above, the convex portion may have a shape in which a conical shape is stacked on a cylindrical shape. In this case, the angle between the side surface and the bottom surface is different from θ1 and θ2. In the case of the convex portion 481 as shown in FIG. 2C, it is preferable that θ1 is not less than 84 degrees and less than 90 degrees, and the height H is the height of a conical portion in which the side surface of the convex portion is skewed.

FIG. 3 shows an example of the shape of the antireflection film having a plurality of convex portions. 3A to 3C show examples in which a plurality of convex portions are installed differently on the display screen surface. 3A2 to 3C are top views, FIG. 3A1 is a cross-sectional view taken along line X1-Y1 in FIG. 3A2, and FIG. 3B1 is taken along line X2-Y2 in FIG. 3B2. FIG. 3C1 is a cross-sectional view taken along line X3-Y3 in FIG. 3C2.

3A1 and 3A2 illustrate an example in which a plurality of convex portions 466a to 466d are adjacent to each other with a certain interval on the display screen of the display device 465. FIG. As described above, the convex portions are not necessarily in contact with each other on the display screen. In the present invention, the convex portions provided with such an interval are also referred to as an antireflection film as a general term for portions having an antireflection function. Therefore, even if the film is not physically continuous, it is referred to as an antireflection film.

3B1 and 3B2 are examples in which a plurality of convex portions 476a to 476d are in close contact with each other on the display screen of the display device 475. As shown in FIGS. 3 (B1) and 3 (B2), the plurality of convex portions are installed in contact with each other so as to cover the display screen densely. Thus, if the surface of the display screen is covered as much as possible with the conical convex portion, the amount of light incident on the antireflection film is increased.

3C1 and 3C2 illustrate an example in which an antireflection film 486 having a plurality of convex portions is provided on the display screen of the display device 485. FIG. As shown in FIGS. 3C1 and 3C, the plurality of convex portions of the antireflection film may be formed as an integral continuous film, and the plurality of convex portions may be provided on the surface of the antireflection film. Thus, various shapes having a plurality of convex portions can be applied to the antireflection film of the present invention.

Further, the antireflection film can be formed of a material whose refractive index changes from the surface toward the display screen instead of a uniform refractive index. For example, in the plurality of convex portions, the convex portion surface side is formed of a material having a refractive index equivalent to that of air, and has a structure that reduces reflection of the convex surface of external light incident on the convex portion more than air. On the other hand, a plurality of convex portions are formed of a material having a refractive index equivalent to that of the substrate as they approach the substrate side on the display screen side, and travel through the convex portions, and at the interface between the convex portions of light incident on the substrate and the substrate. To reduce the reflection of light. When a glass substrate is used as the substrate, the refractive index of air is smaller than that of the glass substrate, so that the convex portion is formed of a material having a lower refractive index on the surface (the tip portion if conical), and the bottom surface of the convex portion The refractive index may be increased from the conical tip portion toward the bottom surface as it is made of a material having a high refractive index as it approaches.

What is necessary is just to set suitably as a material which forms an antireflection film according to the material of the board | substrate which comprises the display screen surface, such as silicon, nitrogen, a fluorine, an oxide, nitride, and fluoride. Examples of the oxide include silicon oxide (SiO ₂ ), boric acid (B ₂ O ₃ ), sodium oxide (NaO ₂ ), magnesium oxide (MgO), aluminum oxide (alumina) (Al ₂ O ₃ ), and potassium oxide (K ₂ O), calcium oxide (CaO), arsenic trioxide (arsenous acid) (As ₂ O ₃ ), strontium oxide (SrO), antimony oxide (Sb ₂ O ₃ ), barium oxide (BaO), indium tin oxide (ITO), zinc oxide (ZnO), indium oxide mixed with zinc oxide (ZnO) IZO (indium zinc oxide), indium oxide mixed with silicon oxide (SiO ₂ ), conductive material, organic indium, organic tin, Indium oxide containing tungsten oxide, Indium zinc oxide containing tungsten oxide, Titanium oxide included Indium oxide, or the like can be used indium tin oxide containing titanium oxide. As the nitride, aluminum nitride (AlN), silicon nitride (SiN), or the like can be used. As the fluoride, lithium fluoride (LiF), sodium fluoride (NaF), magnesium fluoride (MgF ₂ ), calcium fluoride (CaF ₂ ), lanthanum fluoride (LaF ₃ ), or the like can be used. The silicon, nitrogen, fluorine, oxide, nitride, and fluoride may include one or more kinds, and the mixing ratio may be set as appropriate depending on the component ratio (composition ratio) of each substrate.

The antireflection film having a plurality of protrusions is formed into a thin film by a CVD method (Chemical Vapor Deposition) such as a sputtering method, a vacuum deposition method, a PVD method (Physical Vapor Deposition), a low pressure CVD method (LPCVD method), or a plasma CVD method. After film formation, it can be formed by etching into a desired shape. In addition, a droplet discharge method that can selectively form a pattern, a printing method that can transfer or depict a pattern (a method that forms a pattern such as screen printing or offset printing), other coating methods such as spin coating, dipping method, A dispenser method or the like can also be used. In addition, an imprint technique and a nanoimprint technique capable of forming a three-dimensional structure at the nm level by a transfer technique can also be used. Imprinting and nanoimprinting are techniques that can form fine three-dimensional structures without using a photolithography process.

The antireflection function of the antireflection film having a plurality of convex portions according to the present invention will be described with reference to FIG. FIG. 25 shows an antireflection film having convex portions 411 a, 411 b, 411 c, and 411 d adjacent to each other on the display screen of the display device 410. The external light 412a is incident on the convex portion 411c, part of it is transmitted as transmitted light 413a, and the other is reflected as reflected light 412b at the interface of the convex portion 411c. The reflected light 412b is incident again on the adjacent convex portion 411b, part of which is transmitted as transmitted light 413b, and the other is reflected as reflected light 412c at the interface of the convex portion 411b. The reflected light 412c is incident on the adjacent convex portion 411c again, part of which is transmitted as transmitted light 413c, and the other is reflected as reflected light 412d at the interface of the convex portion 411c. The reflected light 412d is again incident on the adjacent convex portion 411b, and a part thereof is transmitted light 413d.

As described above, the display device having the antireflection film of this embodiment has a plurality of convex portions on the surface, and the reflected light of the external light is not reflected on the viewing side because the convex portion interface is not flat. Reflects on other convex parts. Or it progresses between convex parts. The incident external light is partially transmitted through the convex portion, and the reflected light is incident on the adjacent convex portion again. Thus, the external light reflected by the convex interface repeatedly enters the other adjacent convex part.

That is, the number of external light incident on the display device that is incident on the antireflection film increases, so that the amount of light transmitted through the antireflection film increases. Therefore, the external light reflected on the viewer side is reduced, and the cause of lower visibility such as reflection can be prevented.

INDUSTRIAL APPLICABILITY The present invention can provide a display device with high visibility having a high antireflection function that can reduce reflection of external light by providing an antireflection film having a plurality of convex portions on the surface. Therefore, a display device with high image quality and high performance can be manufactured according to the present invention.

(Embodiment 2)
In this embodiment, an example of a display device that has an antireflection function that can reduce reflection of external light and has excellent visibility will be described. More specifically, the case where the structure of the display device is a passive matrix type will be described.

The display device includes a first electrode layer 751a, a first electrode layer 751b, a first electrode layer 751c, a first electrode layer 751a, a first electrode layer 751b, and a first electrode extending in the first direction. An electroluminescent layer 752 provided to cover the layer 751c, and a second electrode layer 753a, a second electrode layer 753b, and a second electrode layer 753c extending in a second direction perpendicular to the first direction. (See FIGS. 5A and 5B.) An electroluminescent layer 752 is provided between the first electrode layer 751a, the first electrode layer 751b, the first electrode layer 751c and the second electrode layer 753a, the second electrode layer 753b, and the second electrode layer 753c. Is provided. An insulating layer 754 that functions as a protective film is provided so as to cover the second electrode layer 753a, the second electrode layer 753b, and the second electrode layer 753c (see FIGS. 5A and 5B). ). Note that in the case where there is a concern about the influence of a horizontal electric field between adjacent light emitting elements, the electroluminescent layer 752 provided in each light emitting element may be separated.

FIG. 5C is a modification example of FIG. 5B, and includes a first electrode layer 791a, a first electrode layer 791b, a first electrode layer 791c, an electroluminescent layer 792, and a second electrode layer 793b. An insulating layer 794 which is a protective layer is provided. As in the first electrode layer 791a, the first electrode layer 791b, and the first electrode layer 791c in FIG. 2C, the first electrode layer may have a tapered shape, and the curvature radius may be continuous. The shape may change. Shapes such as the first electrode layer 791a, the first electrode layer 791b, and the first electrode layer 791c can be formed by a droplet discharge method or the like. When the curved surface has such a curvature, the insulating layer and the conductive layer to be stacked have good coverage.

In addition, a partition wall (insulating layer) may be formed so as to cover an end portion of the first electrode layer. The partition wall (insulating layer) serves as a wall separating other light emitting elements. 6A and 6B illustrate a structure in which the end portion of the first electrode layer is covered with a partition wall (insulating layer).

6A, the partition wall (insulating layer) 775 is tapered so as to cover end portions of the first electrode layer 771a, the first electrode layer 771b, and the first electrode layer 771c. It is formed in the shape which has. A partition (insulating layer) 775 is formed over the first electrode layer 771a, the first electrode layer 771b, and the first electrode layer 771c provided in contact with the substrate 779, and the electroluminescent layer 772 and the second electrode. A layer 773b and an insulating layer 774 are provided over the substrate 778 with the insulating layer 776 interposed therebetween.

An example of the light-emitting element illustrated in FIG. 6B has a shape in which the partition wall (insulating layer) 765 has a curvature, and the radius of curvature continuously changes. A first electrode layer 761a, a first electrode layer 761b, a first electrode layer 761c, an electroluminescent layer 762, a second electrode layer 763b, an insulating layer 764, and a protective layer 768 are provided.

FIG. 4 shows a passive matrix liquid crystal display device to which the present invention is applied. In FIG. 4, a substrate 1700 provided with first pixel electrode layers 1701a, 1701b, and 1701c, an insulating layer 1712 functioning as an alignment film, an insulating layer 1704 functioning as an alignment film, a counter electrode layer 1705, and a color filter function. The colored layer 1706 and the substrate 1710 provided with the polarizing plate 1714 are opposed to each other with the liquid crystal layer 1703 interposed therebetween.

The present invention is characterized in that, in the display device, an antireflection film having a plurality of convex portions is used as an antireflection film having an antireflection function for preventing reflection of external light on the display screen surface. The convex portion of the antireflection film of the present invention is preferably conical, and the angle between the bottom surface and the side surface of the convex portion is preferably 84 degrees or more and less than 90 degrees. In this embodiment mode, antireflection films 757, 797, 777, 767, and 1707 are provided on the surfaces of the substrates 758, 798, 778, 769, and 1710 on the display screen viewing side. The antireflection films 757, 797, 777, 767, and 1707 are antireflection films having a plurality of convex portions. In the present embodiment, the convex portions are conical.

In addition to the conical shape, the convex portion may have a needle shape, a trapezoidal shape in which the tip of the cone is flat, or a dome shape with a rounded tip. Further, the antireflection film can be formed of a material whose refractive index changes from the surface toward the display screen instead of a uniform refractive index. For example, in the plurality of convex portions, the convex portion surface side is formed of a material having a refractive index equivalent to that of air, and has a structure that reduces reflection of the convex surface of external light incident on the convex portion more than air. On the other hand, a plurality of convex portions are formed of a material having a refractive index equivalent to that of the substrate as they approach the substrate side on the display screen side, and travel through the convex portions, and at the interface between the convex portions of light incident on the substrate and the substrate. To reduce the reflection of light. When a glass substrate is used as the substrate, the refractive index of air is smaller than that of the glass substrate, so that the convex portion is formed of a material having a lower refractive index on the surface (the tip portion if conical), and the bottom surface of the convex portion The refractive index may be increased from the conical tip portion toward the bottom surface as it is made of a material having a high refractive index as it approaches.

What is necessary is just to set suitably as a material which forms an antireflection film according to the material of the board | substrate which comprises the display screen surface, such as silicon, nitrogen, a fluorine, an oxide, nitride, and fluoride. Examples of the oxide include silicon oxide (SiO ₂ ), boric acid (B ₂ O ₃ ), sodium oxide (NaO ₂ ), magnesium oxide (MgO), aluminum oxide (alumina) (Al ₂ O ₃ ), and potassium oxide (K ₂ O), calcium oxide (CaO), arsenic trioxide (arsenous acid) (As ₂ O ₃ ), strontium oxide (SrO), antimony oxide (Sb ₂ O ₃ ), barium oxide (BaO), indium tin oxide (ITO), zinc oxide (ZnO), indium oxide mixed with zinc oxide (ZnO) IZO (indium zinc oxide), indium oxide mixed with silicon oxide (SiO ₂ ), conductive material, organic indium, organic tin, Indium oxide containing tungsten oxide, Indium zinc oxide containing tungsten oxide, Titanium oxide included Indium oxide, or the like can be used indium tin oxide containing titanium oxide. As the nitride, aluminum nitride (AlN), silicon nitride (SiN), or the like can be used. As the fluoride, lithium fluoride (LiF), sodium fluoride (NaF), magnesium fluoride (MgF ₂ ), calcium fluoride (CaF ₂ ), lanthanum fluoride (LaF ₃ ), or the like can be used. The silicon, nitrogen, fluorine, oxide, nitride, and fluoride may include one or more kinds, and the mixing ratio may be set as appropriate depending on the component ratio (composition ratio) of each substrate.

The antireflection film having a plurality of protrusions is formed into a thin film by a CVD method (Chemical Vapor Deposition) such as a sputtering method, a vacuum deposition method, a PVD method (Physical Vapor Deposition), a low pressure CVD method (LPCVD method), or a plasma CVD method. After film formation, it can be formed by etching into a desired shape. In addition, a droplet discharge method that can selectively form a pattern, a printing method that can transfer or depict a pattern (a method that forms a pattern such as screen printing or offset printing), other coating methods such as spin coating, dipping method, A dispenser method or the like can also be used. In addition, an imprint technique and a nanoimprint technique capable of forming a three-dimensional structure at the nm level by a transfer technique can also be used. Imprinting and nanoimprinting are techniques that can form fine three-dimensional structures without using a photolithography process.

The display device having the antireflection film of this embodiment has a plurality of convex portions on the surface, and the reflected light of outside light is not reflected on the viewer side because the convex portion interface is not flat. Reflects to the convex part. Or it progresses between convex parts. The incident external light is partially transmitted through the convex portion, and the reflected light is incident on the adjacent convex portion again. Thus, the external light reflected by the convex interface repeatedly enters the other adjacent convex part.

That is, the number of external light incident on the display device that is incident on the antireflection film increases, so that the amount of light transmitted through the antireflection film increases. Therefore, the external light reflected on the viewer side is reduced, and the cause of lower visibility such as reflection can be prevented.

As the substrates 758, 759, 769, 778, 779, 798, 799, 1700, and 1710, a glass substrate, a quartz substrate, or the like can be used. A flexible substrate may be used. The flexible substrate is a substrate that can be bent (flexible), and examples thereof include a plastic substrate made of polycarbonate, polyarylate, polyethersulfone, or the like. A film (made of polypropylene, polyester, vinyl, polyvinyl fluoride, vinyl chloride, polyamide, or the like), an inorganic vapor deposition film, or the like can also be used.

As the partition wall (insulating layer) 765 and the partition wall (insulating layer) 775, silicon oxide, silicon nitride, silicon oxynitride, aluminum oxide, aluminum nitride, aluminum oxynitride, and other inorganic insulating materials, acrylic acid, methacrylic acid, and the like Or a heat resistant polymer such as polyimide, aromatic polyamide, polybenzimidazole, or a siloxane resin. Further, a resin material such as a vinyl resin such as polyvinyl alcohol or polyvinyl butyral, an epoxy resin, a phenol resin, a novolac resin, an acrylic resin, a melamine resin, or a urethane resin is used. Alternatively, an organic material such as benzocyclobutene, parylene, fluorinated arylene ether, or polyimide, a composition material containing a water-soluble homopolymer and a water-soluble copolymer, or the like may be used. As a manufacturing method, a vapor deposition method such as a plasma CVD method or a thermal CVD method, or a sputtering method can be used. Alternatively, a droplet discharge method or a printing method (a method for forming a pattern such as screen printing or offset printing) can be used. A film obtained by a coating method, an SOG film, or the like can also be used.

Further, after a conductive layer, an insulating layer, or the like is formed by discharging a composition by a droplet discharge method, the surface may be flattened by pressing with a pressure in order to improve the flatness. As a pressing method, the surface may be reduced by smoothing the surface by scanning a roller-shaped object, or the surface may be pressed vertically with a flat plate-like object. A heating step may be performed when pressing. Alternatively, the surface may be softened or melted with a solvent or the like, and the surface irregularities may be removed with an air knife. Further, polishing may be performed using a CMP method. This step can be applied when the surface is flattened when unevenness is generated by the droplet discharge method.

INDUSTRIAL APPLICABILITY The present invention can provide a display device with high visibility having a high antireflection function that can reduce reflection of external light by providing an antireflection film having a plurality of convex portions on the surface. Therefore, a display device with high image quality and high performance can be manufactured according to the present invention.

This embodiment mode can be freely combined with Embodiment Mode 1 described above.

(Embodiment 3)
In this embodiment, an example of a display device that has an antireflection function that can reduce reflection of external light and has excellent visibility will be described. In this embodiment mode, a display device having a structure different from that of Embodiment Mode 2 will be described. Specifically, the case where the structure of the display device is an active matrix type is described.

A top view of the display device is shown in FIG. 36A, and a cross-sectional view taken along line EF in FIG. 36A is shown in FIG. In FIG. 36A, the electroluminescent layer 532, the second electrode layer 533, and the insulating layer 534 are omitted and not shown, but are provided as shown in FIG.

A first wiring extending in a first direction and a second wiring extending in a second direction perpendicular to the first direction are formed in a matrix over a substrate 520 provided with an insulating layer 523 as a base film. Is provided. The first wiring is connected to the source electrode or the drain electrode of the transistor 521, and the second wiring is connected to the gate electrode of the transistor 521. Further, the first electrode layer 531 is connected to the wiring layer 525b which is a source electrode or a drain electrode of the transistor 521 which is not connected to the first wiring, and the first electrode layer 531, the electroluminescent layer 532, and the second layer A light-emitting element 530 is provided by a stacked structure of the electrode layers 533. A partition wall (insulating layer) 528 is provided between each adjacent light emitting element, and an electroluminescent layer 532 and a second electrode layer 533 are stacked over the first electrode layer and the partition wall (insulating layer) 528. Yes. An insulating layer 534 serving as a protective layer and a substrate 538 which is a sealing substrate are provided over the second electrode layer 533. Further, an inverted staggered thin film transistor is used as the transistor 521 (see FIG. 36). Light emitted from the light emitting element 530 is extracted from the substrate 524 side. Therefore, the surface of the substrate 538 on the viewing side has the antireflection film 529 having a plurality of convex portions of the present invention.

In FIG. 36 in this embodiment, the transistor 521 is an example of a channel-etched inverted staggered transistor. 36, a transistor 521 includes a gate electrode layer 502, a gate insulating layer 526, a semiconductor layer 504, semiconductor layers 503a and 503b having one conductivity type, and wiring layers 525a and 525b which are source or drain electrode layers.

As a material for forming the semiconductor layer, an amorphous semiconductor (hereinafter also referred to as “amorphous semiconductor: AS”) manufactured by a vapor deposition method or a sputtering method using a semiconductor material gas typified by silane or germane is used. A polycrystalline semiconductor obtained by crystallizing a crystalline semiconductor using light energy or thermal energy, or a semi-amorphous (also referred to as microcrystal or microcrystal; hereinafter, also referred to as “SAS”) semiconductor can be used.

SAS is a semiconductor having an intermediate structure between amorphous and crystalline structures (including single crystal and polycrystal) and having a third state that is stable in terms of free energy and has a short-range order and a lattice. It includes a crystalline region with strain. SAS is formed by glow discharge decomposition (plasma CVD) of a gas containing silicon. As a gas containing silicon, SiH ₄ , Si ₂ H ₆ , SiH ₂ Cl ₂ , SiHCl ₃ , SiCl ₄ , SiF _4, or the like can be used. Further, F ₂ and GeF ₄ may be mixed. The gas containing silicon may be diluted with H ₂ , or H ₂ and one or more kinds of rare gas elements selected from He, Ar, Kr, and Ne. Further, by adding a rare gas element such as helium, argon, krypton, or neon to further promote lattice distortion, stability is improved and a favorable SAS can be obtained. In addition, a SAS layer formed of a hydrogen-based gas may be stacked on a SAS layer formed of a fluorine-based gas as a semiconductor film.

A typical example of an amorphous semiconductor is hydrogenated amorphous silicon, and a typical example of a crystalline semiconductor is polysilicon. Polysilicon (polycrystalline silicon) is mainly made of so-called high-temperature polysilicon using polysilicon formed through a process temperature of 800 ° C. or higher as a main material, or polysilicon formed at a process temperature of 600 ° C. or lower. And so-called low-temperature polysilicon, and polysilicon crystallized by adding an element that promotes crystallization. Needless to say, as described above, a semi-amorphous semiconductor or a semiconductor containing a crystal phase in part of a semiconductor film can also be used.

In the case where a crystalline semiconductor film is used as the semiconductor film, a method for manufacturing the crystalline semiconductor film can be a known method (laser crystallization method, thermal crystallization method, or heat using an element that promotes crystallization such as nickel. A crystallization method or the like may be used. In addition, a microcrystalline semiconductor that is a SAS can be crystallized by laser irradiation to improve crystallinity. In the case where an element for promoting crystallization is not introduced, the concentration of hydrogen contained in the amorphous semiconductor film is set to 1 × by heating at 500 ° C. for 1 hour in a nitrogen atmosphere before irradiating the amorphous semiconductor film with laser light. Release to 10 ²⁰ atoms / cm ³ or less. This is because when an amorphous semiconductor film containing a large amount of hydrogen is irradiated with laser light, the amorphous semiconductor film is destroyed. As the heat treatment for crystallization, a heating furnace, laser irradiation, irradiation with light emitted from a lamp (also referred to as lamp annealing), or the like can be used. There are RTA methods such as a GRTA (Gas Rapid Thermal Anneal) method and an LRTA (Lamp Rapid Thermal Anneal) method as heating methods. GRTA is a method for performing heat treatment using a high-temperature gas, and LRTA is a method for performing heat treatment with lamp light.

Further, in the crystallization step of crystallizing the amorphous semiconductor layer to form the crystalline semiconductor layer, an element for promoting crystallization (also referred to as a catalyst element or a metal element) is added to the amorphous semiconductor layer, and heat treatment ( Crystallization may be carried out at 550 ° C. to 750 ° C. for 3 minutes to 24 hours. As elements for promoting crystallization, metal elements for promoting crystallization of silicon include iron (Fe), nickel (Ni), cobalt (Co), ruthenium (Ru), rhodium (Rh), palladium (Pd). One or plural types selected from osmium (Os), iridium (Ir), platinum (Pt), copper (Cu), and gold (Au) can be used.

The method of introducing the metal element into the amorphous semiconductor film is not particularly limited as long as the metal element can be present on the surface of the amorphous semiconductor film or inside the amorphous semiconductor film. For example, sputtering, CVD, A plasma treatment method (including a plasma CVD method), an adsorption method, or a method of applying a metal salt solution can be used. Among these, the method using a solution is simple and useful in that the concentration of the metal element can be easily adjusted. At this time, in order to improve the wettability of the surface of the amorphous semiconductor film and to spread the aqueous solution over the entire surface of the amorphous semiconductor film, irradiation with UV light in an oxygen atmosphere, thermal oxidation method, hydroxy radical It is desirable to form an oxide film by treatment with ozone water or hydrogen peroxide.

In order to remove or reduce the element that promotes crystallization from the crystalline semiconductor layer, a semiconductor layer containing an impurity element is formed in contact with the crystalline semiconductor layer and functions as a gettering sink. As the impurity element, an impurity element imparting n-type conductivity, an impurity element imparting p-type conductivity, a rare gas element, or the like can be used. For example, phosphorus (P), nitrogen (N), arsenic (As), antimony (Sb ), Bismuth (Bi), boron (B), helium (He), neon (Ne), argon (Ar), Kr (krypton), and Xe (xenon) can be used. A semiconductor layer containing a rare gas element is formed over the crystalline semiconductor layer containing an element that promotes crystallization, and heat treatment (at 550 ° C. to 750 ° C. for 3 minutes to 24 hours) is performed. The element that promotes crystallization contained in the crystalline semiconductor layer moves into the semiconductor layer containing a rare gas element, and the element that promotes crystallization in the crystalline semiconductor layer is removed or reduced. After that, the semiconductor layer containing a rare gas element that has become a gettering sink is removed.

Laser irradiation can be performed by relatively scanning the laser and the semiconductor film. In laser irradiation, a marker can be formed in order to superimpose beams with high accuracy and to control the laser irradiation start position and laser irradiation end position. The marker may be formed on the substrate simultaneously with the amorphous semiconductor film.

When laser irradiation is used, a continuous wave laser beam (CW (continuous-wave) laser beam) or a pulsed laser beam (pulse laser beam) can be used. The laser beam that can be used here is a gas laser such as an Ar laser, a Kr laser, or an excimer laser, single crystal YAG, YVO ₄ , forsterite (Mg ₂ SiO ₄ ), YAlO ₃ , GdVO ₄ , or polycrystalline ( (Ceramics) YAG, Y ₂ O ₃ , YVO ₄ , YAlO ₃ , GdVO ₄ with one or more of Nd, Yb, Cr, Ti, Ho, Er, Tm, Ta added as dopants A laser oscillated from one or more of laser, glass laser, ruby laser, alexandrite laser, Ti: sapphire laser, copper vapor laser, or gold vapor laser as a medium can be used. By irradiating the fundamental wave of such a laser beam and the second to fourth harmonic laser beams of these fundamental waves, a crystal having a large grain size can be obtained. For example, a second harmonic (532 nm) or a third harmonic (355 nm) of an Nd: YVO ₄ laser (fundamental wave 1064 nm) can be used. This laser can be emitted by CW or pulsed oscillation. When injected at a CW, the power density 0.01 to 100 MW / cm ² of about laser (preferably 0.1 to 10 MW / cm ²⁾ is required. Then, irradiation is performed at a scanning speed of about 10 to 2000 cm / sec.

Note that single crystal YAG, YVO ₄ , forsterite (Mg ₂ SiO ₄ ), YAlO ₃ , GdVO ₄ , or polycrystalline (ceramic) YAG, Y ₂ O ₃ , YVO ₄ , YAlO ₃ , GdVO ₄ , dopants Nd, Yb, Cr, Ti, Ho, Er, Tm, and Ta, a laser using a medium added with one or more, an Ar ion laser, or a Ti: sapphire laser should be continuously oscillated. It is also possible to perform pulse oscillation at an oscillation frequency of 10 MHz or more by performing Q switch operation or mode synchronization. When the laser beam is oscillated at an oscillation frequency of 10 MHz or more, the semiconductor film is irradiated with the next pulse during the period from when the semiconductor film is melted by the laser to solidification. Therefore, unlike the case of using a pulse laser having a low oscillation frequency, the solid-liquid interface can be continuously moved in the semiconductor film, so that crystal grains continuously grown in the scanning direction can be obtained.

When ceramic (polycrystal) is used as the medium, it is possible to form the medium in a free shape in a short time and at low cost. When a single crystal is used, a cylindrical medium having a diameter of several millimeters and a length of several tens of millimeters is usually used. However, when ceramic is used, a larger one can be made.

Since the concentration of dopants such as Nd and Yb in the medium that directly contributes to light emission cannot be changed greatly regardless of whether it is a single crystal or a polycrystal, there is a certain limit to improving the laser output by increasing the concentration. However, in the case of ceramic, since the size of the medium can be remarkably increased as compared with the single crystal, the output can be greatly improved.

Further, in the case of ceramic, a medium having a parallelepiped shape or a rectangular parallelepiped shape can be easily formed. When a medium having such a shape is used to cause oscillation light to travel in a zigzag manner inside the medium, the oscillation optical path can be made longer. As a result, amplification is increased and oscillation can be performed with high output. Further, since the laser beam emitted from the medium having such a shape has a quadrangular cross-sectional shape at the time of emission, it is advantageous for shaping into a linear beam as compared with a round beam. By shaping the emitted laser beam using an optical system, it is possible to easily obtain a linear beam having a short side length of 1 mm or less and a long side length of several mm to several m. Become. In addition, by irradiating the medium with the excitation light uniformly, the linear beam has a uniform energy distribution in the long side direction. Further, the laser may be irradiated with an incident angle θ (0 <θ <90 degrees) with respect to the semiconductor film. This is because laser interference can be prevented.

By irradiating the semiconductor film with this linear beam, the entire surface of the semiconductor film can be annealed more uniformly. When uniform annealing is required up to both ends of the linear beam, it is necessary to arrange a slit at both ends to shield the energy attenuating portion.

When a semiconductor film is annealed using a linear beam with uniform intensity obtained in this way and a display device is manufactured using this semiconductor film, the characteristics of the display device are good and uniform.

Further, laser light may be irradiated in an inert gas atmosphere such as a rare gas or nitrogen. Accordingly, the surface roughness of the semiconductor can be suppressed by laser light irradiation, and variations in threshold values caused by variations in interface state density can be suppressed.

Crystallization of the amorphous semiconductor film may be a combination of heat treatment and crystallization by laser light irradiation, or may be performed multiple times by heat treatment or laser light irradiation alone.

The gate electrode layer can be formed by a technique such as sputtering, vapor deposition, or CVD. The gate electrode layer is an element selected from tantalum (Ta), tungsten (W), titanium (Ti), molybdenum (Mo), aluminum (Al), copper (Cu), chromium (Cr), neodymium (Nd), or What is necessary is just to form with the alloy material or compound material which has the said element as a main component. Alternatively, a semiconductor film typified by a polycrystalline silicon film doped with an impurity element such as phosphorus, or an AgPdCu alloy may be used for the gate electrode layer. The gate electrode layer may be a single layer or a stacked layer.

In this embodiment mode, the gate electrode layer is formed to have a tapered shape; however, the present invention is not limited thereto, and the gate electrode layer has a stacked structure, and only one layer has a tapered shape, and the other is anisotropic. You may have a vertical side surface by an etching. The taper angle may also be different between the stacked gate electrode layers, or may be the same. By having a tapered shape, the coverage of a film stacked thereon is improved and defects are reduced, so that reliability is improved.

The source electrode layer or the drain electrode layer can be formed by forming a conductive film by a PVD method, a CVD method, an evaporation method, or the like and then etching the conductive film into a desired shape. In addition, a conductive layer can be selectively formed at a predetermined place by a droplet discharge method, a printing method, a dispenser method, an electroplating method, or the like. Furthermore, a reflow method or a damascene method may be used. The material of the source electrode layer or the drain electrode layer is Ag, Au, Cu, Ni, Pt, Pd, Ir, Rh, W, Al, Ta, Mo, Cd, Zn, Fe, Ti, Si, Ge, Zr, Ba Or a metal nitride thereof or a metal nitride thereof. Moreover, it is good also as these laminated structures.

As the insulating layers 523, 526, 527, and 534, silicon oxide, silicon nitride, silicon oxynitride, aluminum oxide, aluminum nitride, aluminum oxynitride, and other inorganic insulating materials, acrylic acid, methacrylic acid, and derivatives thereof, or A heat-resistant polymer such as polyimide, aromatic polyamide, polybenzimidazole, or siloxane resin may be used. Further, a resin material such as a vinyl resin such as polyvinyl alcohol or polyvinyl butyral, an epoxy resin, a phenol resin, a novolac resin, an acrylic resin, a melamine resin, or a urethane resin is used. Alternatively, an organic material such as benzocyclobutene, parylene, fluorinated arylene ether, or polyimide, a composition material containing a water-soluble homopolymer and a water-soluble copolymer, or the like may be used. As a manufacturing method, a vapor deposition method such as a plasma CVD method or a thermal CVD method, or a sputtering method can be used. Alternatively, a droplet discharge method or a printing method (a method for forming a pattern such as screen printing or offset printing) can be used. A film obtained by a coating method, an SOG film, or the like can also be used.

Further, after a conductive layer, an insulating layer, or the like is formed by discharging a composition by a droplet discharge method, the surface may be flattened by pressing with a pressure in order to improve the flatness. As a pressing method, the surface may be reduced by smoothing the surface by scanning a roller-shaped object, or the surface may be pressed vertically with a flat plate-like object. A heating step may be performed when pressing. Alternatively, the surface may be softened or melted with a solvent or the like, and the surface irregularities may be removed with an air knife. Further, polishing may be performed using a CMP method. This step can be applied when the surface is flattened when unevenness is generated by the droplet discharge method.

Without being limited to this embodiment mode, the thin film transistor may have a single gate structure in which one channel formation region is formed, a double gate structure in which two channel formation regions are formed, or a triple gate structure in which three channel formation regions are formed. The thin film transistor in the peripheral driver circuit region may have a single gate structure, a double gate structure, or a triple gate structure.

Note that the gate insulating film is not limited to the method for manufacturing the thin film transistor described in this embodiment mode, and may be a top gate type (eg, a forward stagger type or a coplanar type), a bottom gate type (eg, a reverse coplanar type), or a gate insulating film above and below a channel region. The present invention can also be applied to a dual gate type or other structure having two gate electrode layers arranged via each other.

7A and 7B show an active matrix liquid crystal display device to which the present invention is applied. In FIG. 7, a substrate 550 provided with a multi-gate transistor 551, a pixel electrode layer 560, and an insulating layer 561 functioning as an alignment film over a substrate 550, an insulating layer 563 functioning as an alignment film, and a counter electrode layer. A conductive layer 564, a colored layer 565 functioning as a color filter, and a substrate 568 provided with a polarizer (also referred to as a polarizing plate) 556 are opposed to each other with the liquid crystal layer 562 interposed therebetween. An antireflection film 567 having a plurality of convex portions of the present invention is provided on the surface of the substrate 568 on the viewing side.

In the display device in FIG. 7A, an example in which an antireflection film 567 is provided outside the substrate 568 and a polarizer 556, a colored layer 565, and a conductive layer 564 are provided in this order is shown in FIG. 7B. As described above, the polarizer 569 may be provided on the outer side (viewing side) of the substrate 568. In that case, an antireflection film 567 may be provided on the surface of the polarizer 569. The stacked structure of the polarizer and the colored layer is not limited to that shown in FIG. 7A, and may be set as appropriate depending on the material of the polarizer and the colored layer and manufacturing process conditions.

FIG. 13 shows active matrix electronic paper to which the present invention is applied. Although FIG. 13 shows an active matrix type, the present invention can also be applied to a passive matrix type.

Although FIG. 7 shows an example using a liquid crystal display element as a display element, a display device using a twisting ball display method may be used. In the twist ball display system, spherical particles that are separately painted in white and black are arranged between the first electrode layer and the second electrode layer, and a potential difference is generated between the first electrode layer and the second electrode layer. The display is performed by controlling the direction of the spherical particles.

The transistor 581 is a reverse coplanar thin film transistor and includes a gate electrode layer 582, a gate insulating layer 584, a wiring layer 585 a, a wiring layer 585 b, and a semiconductor layer 586. The wiring layer 585b is in contact with and electrically connected to the first electrode layers 587a and 587b through an opening formed in the insulating layer 598. Between the first electrode layers 587a and 587b and the second electrode layer 588, there are provided spherical particles 589 having a black region 590a and a white region 590b and including a cavity 594 filled with liquid. The periphery of the spherical particles 589 is filled with a filler 595 such as a resin (see FIG. 13). On the surface of the substrate 596 on the viewing side, an antireflection film 597 having a plurality of convex portions of the present invention is provided.

Further, instead of the twisting ball, an electrophoretic element can be used. A microcapsule having a diameter of about 10 μm to 200 μm in which transparent liquid, positively charged white microparticles, and negatively charged black microparticles are enclosed is used. In the microcapsule provided between the first electrode layer and the second electrode layer, when an electric field is applied by the first electrode layer and the second electrode layer, the white particles and the black particles are in opposite directions. And can display white or black. A display element using this principle is an electrophoretic display element, and is generally called electronic paper. Since the electrophoretic display element has higher reflectance than the liquid crystal display element, an auxiliary light is unnecessary, power consumption is small, and the display portion can be recognized even in a dim place. In addition, even when power is not supplied to the display unit, it is possible to retain the image once displayed. Therefore, even when the semiconductor device with a display function is moved away from the radio wave source, it is displayed. The image can be stored.

The transistor may have any structure as long as it can function as a switching element. As the semiconductor layer, various semiconductors such as an amorphous semiconductor, a crystalline semiconductor, a polycrystalline semiconductor, and a microcrystalline semiconductor can be used, and an organic transistor may be formed using an organic compound.

The present invention is characterized in that, in the display device, an antireflection film having a plurality of convex portions is used as an antireflection film having an antireflection function for preventing reflection of external light on the display screen surface. The convex portion of the antireflection film of the present invention is preferably conical, and the angle between the bottom surface and the side surface of the convex portion is preferably 84 degrees or more and less than 90 degrees. In this embodiment mode, antireflection films 529, 567, and 597 are provided on the surfaces of the substrates 538, 568, and 596 on the display screen viewing side. The antireflection films 529, 567, and 597 are antireflection films having a plurality of convex portions. In the present embodiment, the convex portions are conical.

In addition to the conical shape, the convex portion may have a needle shape, a trapezoidal shape in which the tip of the cone is flat, or a dome shape with a rounded tip. Further, the antireflection film can be formed of a material whose refractive index changes from the surface toward the display screen instead of a uniform refractive index. For example, in the plurality of convex portions, the convex portion surface side is formed of a material having a refractive index equivalent to that of air, and has a structure that reduces reflection of the convex surface of external light incident on the convex portion more than air. On the other hand, a plurality of convex portions are formed of a material having a refractive index equivalent to that of the substrate as they approach the substrate side on the display screen side, and travel through the convex portions, and at the interface between the convex portions of light incident on the substrate and the substrate. To reduce the reflection of light. When a glass substrate is used as the substrate, the refractive index of air is smaller than that of the glass substrate, so that the convex portion is formed of a material having a lower refractive index on the surface (the tip portion if conical), and the bottom surface of the convex portion The refractive index may be increased from the conical tip portion toward the bottom surface as it is made of a material having a high refractive index as it approaches.

What is necessary is just to set suitably as a material which forms an antireflection film according to the material of the board | substrate which comprises the display screen surface, such as silicon, nitrogen, a fluorine, an oxide, nitride, and fluoride. Examples of the oxide include silicon oxide (SiO ₂ ), boric acid (B ₂ O ₃ ), sodium oxide (NaO ₂ ), magnesium oxide (MgO), aluminum oxide (alumina) (Al ₂ O ₃ ), and potassium oxide (K ₂ O), calcium oxide (CaO), arsenic trioxide (arsenous acid) (As ₂ O ₃ ), strontium oxide (SrO), antimony oxide (Sb ₂ O ₃ ), barium oxide (BaO), indium tin oxide (ITO), zinc oxide (ZnO), indium oxide mixed with zinc oxide (ZnO) IZO (indium zinc oxide), indium oxide mixed with silicon oxide (SiO ₂ ), conductive material, organic indium, organic tin, Indium oxide containing tungsten oxide, Indium zinc oxide containing tungsten oxide, Titanium oxide included Indium oxide, or the like can be used indium tin oxide containing titanium oxide. As the nitride, aluminum nitride (AlN), silicon nitride (SiN), or the like can be used. As the fluoride, lithium fluoride (LiF), sodium fluoride (NaF), magnesium fluoride (MgF ₂ ), calcium fluoride (CaF ₂ ), lanthanum fluoride (LaF ₃ ), or the like can be used. The silicon, nitrogen, fluorine, oxide, nitride, and fluoride may include one or more kinds, and the mixing ratio may be set as appropriate depending on the component ratio (composition ratio) of each substrate.

The antireflection film having a plurality of protrusions is formed into a thin film by a CVD method (Chemical Vapor Deposition) such as a sputtering method, a vacuum deposition method, a PVD method (Physical Vapor Deposition), a low pressure CVD method (LPCVD method), or a plasma CVD method. After film formation, it can be formed by etching into a desired shape. In addition, a droplet discharge method that can selectively form a pattern, a printing method that can transfer or depict a pattern (a method that forms a pattern such as screen printing or offset printing), other coating methods such as spin coating, dipping method, A dispenser method or the like can also be used. In addition, an imprint technique and a nanoimprint technique capable of forming a three-dimensional structure at the nm level by a transfer technique can also be used. Imprinting and nanoimprinting are techniques that can form fine three-dimensional structures without using a photolithography process.

The display device having the antireflection film of this embodiment has a plurality of convex portions on the surface, and the reflected light of outside light is not reflected on the viewer side because the convex portion interface is not flat. Reflects to the convex part. Or it progresses between convex parts. The incident external light is partially transmitted through the convex portion, and the reflected light is incident on the adjacent convex portion again. Thus, the external light reflected by the convex interface repeatedly enters the other adjacent convex part.

That is, the number of external light incident on the display device that is incident on the antireflection film increases, so that the amount of light transmitted through the antireflection film increases. Therefore, the external light reflected on the viewer side is reduced, and the cause of lower visibility such as reflection can be prevented.

INDUSTRIAL APPLICABILITY The present invention can provide a display device with high visibility having a high antireflection function that can reduce reflection of external light by providing an antireflection film having a plurality of convex portions on the surface. Therefore, a display device with high image quality and high performance can be manufactured according to the present invention.

This embodiment mode can be freely combined with Embodiment Mode 1 described above.

(Embodiment 4)
In this embodiment mode, an example of a display device which has an antireflection function capable of further reducing reflection of external light and aims to provide excellent visibility will be described. Specifically, a liquid crystal display device using a liquid crystal display element as a display element will be described.

8A is a top view of a liquid crystal display device having an antireflection film, and FIG. 8B is a cross-sectional view taken along line CD in FIG. 8A. In the top view of FIG. 8A, the antireflection film is omitted.

As shown in FIG. 8A, a pixel region 606, a driving circuit region 608a which is a scanning line driving circuit, and a driving circuit region 608b which is a scanning line driving region are formed between a substrate 600 and a counter substrate 695 by a sealant 692. A driving circuit region 607 which is a signal line driving circuit which is sealed in between and formed on the substrate 600 by a driver IC is provided. A transistor 622 and a capacitor 623 are provided in the pixel region 606, and a driver circuit including a transistor 620 and a transistor 621 is provided in the driver circuit region 608b. For the substrate 600, an insulating substrate similar to that in the above embodiment can be used. In general, substrates made of synthetic resin have a concern that the heat-resistant temperature is lower than other substrates, but they can also be adopted by transposing after a manufacturing process using a substrate with high heat resistance. Is possible.

In the pixel region 606, a transistor 622 serving as a switching element is provided through a base film 604a and a base film 604b. In this embodiment, a multi-gate thin film transistor (TFT) is used for the transistor 622, a semiconductor layer having an impurity region functioning as a source region and a drain region, a gate insulating layer, a gate electrode layer having a two-layer structure, a source An electrode layer and a drain electrode layer are included, and the source electrode layer or the drain electrode layer is in contact with and electrically connected to the impurity region of the semiconductor layer and the pixel electrode layer 630. Thin film transistors can be manufactured by a number of methods. For example, a crystalline semiconductor film is applied as the active layer. A gate electrode is provided over the crystalline semiconductor film with a gate insulating film interposed therebetween. An impurity element can be added to the active layer using the gate electrode. Thus, it is not necessary to form a mask for adding the impurity element by adding the impurity element using the gate electrode. The gate electrode can have a single-layer structure or a stacked structure. The impurity region can be a high concentration impurity region and a low concentration impurity region by controlling the concentration thereof. A thin film transistor having such a low concentration impurity region is referred to as an LDD (Lightly Doped Drain) structure. The low-concentration impurity region can be formed so as to overlap with the gate electrode. Such a thin film transistor is referred to as a GOLD (Gate Overlapped LDD) structure. The polarity of the thin film transistor is n-type by using phosphorus (P) or the like in the impurity region. When p-type is used, boron (B) or the like may be added. After that, an insulating film 611 and an insulating film 612 that cover the gate electrode and the like are formed. A dangling bond in the crystalline semiconductor film can be terminated by a hydrogen element mixed in the insulating film 611 (and the insulating film 612).

In order to further improve flatness, an insulating film 615 and an insulating film 616 may be formed as interlayer insulating films. For the insulating films 615 and 616, an organic material, an inorganic material, or a stacked structure thereof can be used. For example, silicon oxide, silicon nitride, silicon oxynitride, silicon nitride oxide, aluminum nitride, aluminum oxynitride, aluminum nitride oxide or aluminum oxide whose nitrogen content is higher than oxygen content, diamond like carbon (DLC), polysilazane, nitrogen content It can be formed of a material selected from carbon (CN), PSG (phosphorus glass), BPSG (phosphorus boron glass), alumina, and other inorganic insulating materials. An organic insulating material may be used, and the organic material may be either photosensitive or non-photosensitive, and polyimide, acrylic, polyamide, polyimide amide, resist, benzocyclobutene, siloxane resin, or the like can be used. . Note that a siloxane resin corresponds to a resin including a Si—O—Si bond. Siloxane has a skeleton structure formed of a bond of silicon (Si) and oxygen (O). As a substituent, an organic group containing at least hydrogen (for example, an alkyl group or an aromatic hydrocarbon) is used. A fluoro group may be used as a substituent. Alternatively, an organic group containing at least hydrogen and a fluoro group may be used as a substituent.
The

In addition, by using a crystalline semiconductor film, the pixel region and the driver circuit region can be formed over the same substrate. In that case, the transistor in the pixel region and the transistor in the driver circuit region 608b are formed at the same time. Transistors used for the driver circuit region 608b constitute a CMOS circuit. Although the thin film transistor included in the CMOS circuit has a GOLD structure, an LDD structure such as the transistor 622 can also be used.

Without being limited to this embodiment mode, the thin film transistor in the pixel region may have a single gate structure in which one channel formation region is formed, a double gate structure in which two channel formation regions are formed, or a triple gate structure in which three channel formation regions are formed. . The thin film transistor in the peripheral driver circuit region may have a single gate structure, a double gate structure, or a triple gate structure.

Note that not only the method for manufacturing the thin film transistor described in this embodiment mode, but a top gate type (for example, a forward staggered type), a bottom gate type (for example, an inverted staggered type), or a gate insulating film above and below a channel region is used. The present invention can also be applied to a dual gate type or other structure having two gate electrode layers arranged.

Next, an insulating layer 631 called an alignment film is formed by a printing method or a droplet discharge method so as to cover the pixel electrode layer 630 and the insulating film 616. Note that the insulating layer 631 can be selectively formed by a screen printing method or an offset printing method. Thereafter, a rubbing process is performed. This rubbing process may not be performed in the liquid crystal mode, for example, the VA mode. The insulating layer 633 functioning as an alignment film is similar to the insulating layer 631. Subsequently, a sealant 692 is formed in a peripheral region where pixels are formed by a droplet discharge method.

After that, a counter substrate provided with an insulating layer 633 functioning as an alignment film, a conductive layer 634 functioning as a counter electrode, a colored layer 635 functioning as a color filter, a polarizer 641 (also referred to as a polarizing plate), and an antireflection film 642 695 and a substrate 600 which is a TFT substrate are attached to each other with a spacer 637, and a liquid crystal layer 632 is provided in the gap. Since the liquid crystal display device in this embodiment is a transmissive type, a polarizer (polarizing plate) 643 is provided on the side opposite to the surface of the substrate 600 having elements. The polarizer can be provided on the substrate by an adhesive layer. A filler may be mixed in the sealing material, and a shielding film (black matrix) or the like may be formed on the counter substrate 695. Note that the color filter or the like may be formed from a material exhibiting red (R), green (G), and blue (B) when the liquid crystal display device is set to full color display. It may be formed of a material that eliminates or exhibits at least one color.

8 shows an example in which an antireflection film 642 is provided outside the counter substrate 695 and a polarizer 641 and a colored layer 635 conductive layer 634 are provided in this order, but the polarizer is arranged outside the counter substrate 695. In this case, an antireflection film may be provided on the surface of the polarizer (polarizing plate). Further, the stacked structure of the polarizer and the colored layer is not limited to that shown in FIG. 8 and may be set as appropriate depending on the material of the polarizer and the colored layer and the manufacturing process conditions.

Note that a color filter may not be provided when an RGB light emitting diode (LED) or the like is arranged in the backlight and a continuous additive color mixing method (field sequential method) in which color display is performed by time division is adopted. The black matrix is preferably provided so as to overlap with the transistor or the CMOS circuit in order to reduce reflection of external light due to the wiring of the transistor or the CMOS circuit. Note that the black matrix may be formed so as to overlap with the capacitor. This is because reflection by the metal film constituting the capacitor element can be prevented.

As a method for forming the liquid crystal layer, a dispenser method (a dropping method) or an injection method in which liquid crystal is injected using a capillary phenomenon after the substrate 600 having an element and the counter substrate 695 are bonded to each other can be used. The dropping method is preferably applied when handling a large substrate to which the injection method is difficult to apply.

The spacer may be provided by spraying particles of several μm, but in this embodiment, a method of forming a resin film on the entire surface of the substrate and then etching it is employed. After applying such a spacer material with a spinner, it is formed into a predetermined pattern by exposure and development processing. Further, it is cured by heating at 150 to 200 ° C. in a clean oven or the like. The spacers produced in this way can have different shapes depending on the conditions of exposure and development processing, but preferably, the spacers are columnar and the top is flat, so that the opposite substrate is When combined, the mechanical strength of the liquid crystal display device can be ensured. The shape can be a conical shape, a pyramid shape or the like, and there is no particular limitation.

Subsequently, an FPC 694 that is a wiring board for connection is provided on the terminal electrode layer 678 electrically connected to the pixel region with an anisotropic conductive layer 696 interposed therebetween. The FPC 694 plays a role of transmitting an external signal or potential. Through the above steps, a liquid crystal display device having a display function can be manufactured.

Note that a wiring included in the transistor, a gate electrode layer, a pixel electrode layer 630, and a conductive layer 634 which is a counter electrode layer include indium tin oxide (ITO), indium oxide and zinc oxide (ZnO) mixed in IZO (indium zinc oxide). Indium oxide mixed with silicon oxide (SiO ₂ ), indium oxide, organic tin, indium oxide containing tungsten oxide, indium zinc oxide containing tungsten oxide, indium oxide containing titanium oxide, titanium oxide Indium tin oxide containing, tungsten (W), molybdenum (Mo), zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb), tantalum (Ta), chromium (Cr), cobalt (Co) Nickel (Ni), Titanium (Ti), Platinum (Pt), Aluminum It can be selected from metals such as luminium (Al), copper (Cu), silver (Ag), alloys thereof, or metal nitrides thereof.

You may laminate | stack in the state which had the phase difference plate between the polarizing plate and the liquid-crystal layer.

The present invention is characterized in that, in the display device, an antireflection film having a plurality of convex portions is used as an antireflection film having an antireflection function for preventing reflection of external light on the display screen surface. The convex portion of the antireflection film of the present invention is preferably conical, and the angle between the bottom surface and the side surface of the convex portion is preferably 84 degrees or more and less than 90 degrees. In this embodiment mode, an antireflection film 642 is provided on the surface of the counter substrate 695 on the display screen viewing side. The antireflection film 642 is an antireflection film having a plurality of convex portions, and the convex portions are conical in this embodiment.

In addition to the conical shape, the convex portion may have a needle shape, a trapezoidal shape in which the tip of the cone is flat, or a dome shape with a rounded tip. Further, the antireflection film can be formed of a material whose refractive index changes from the surface toward the display screen instead of a uniform refractive index. For example, in the plurality of convex portions, the convex portion surface side is formed of a material having a refractive index equivalent to that of air, and has a structure that reduces reflection of the convex surface of external light incident on the convex portion more than air. On the other hand, a plurality of convex portions are formed of a material having a refractive index equivalent to that of the substrate as they approach the substrate side on the display screen side, and travel through the convex portions, and at the interface between the convex portions of light incident on the substrate and the substrate. To reduce the reflection of light. When a glass substrate is used as the substrate, the refractive index of air is smaller than that of the glass substrate, so that the convex portion is formed of a material having a lower refractive index on the surface (the tip portion if conical), and the bottom surface of the convex portion The refractive index may be increased from the conical tip portion toward the bottom surface as it is made of a material having a high refractive index as it approaches.

The display device having the antireflection film of this embodiment has a plurality of convex portions on the surface, and the reflected light of outside light is not reflected on the viewer side because the convex portion interface is not flat. Reflects to the convex part. Or it progresses between convex parts. The incident external light is partially transmitted through the convex portion, and the reflected light is incident on the adjacent convex portion again. Thus, the external light reflected by the convex interface repeatedly enters the other adjacent convex part.

That is, the number of external light incident on the display device that is incident on the antireflection film increases, so that the amount of light transmitted through the antireflection film increases. Therefore, the external light reflected on the viewer side is reduced, and the cause of lower visibility such as reflection can be prevented.

INDUSTRIAL APPLICABILITY The present invention can provide a display device with high visibility having a high antireflection function that can reduce reflection of external light by providing an antireflection film having a plurality of convex portions on the surface. Therefore, a display device with high image quality and high performance can be manufactured according to the present invention.

This embodiment mode can be freely combined with Embodiment Mode 1 described above.

(Embodiment 5)
In this embodiment mode, an example of a display device which has an antireflection function capable of further reducing reflection of external light and aims to provide excellent visibility will be described. Specifically, a light-emitting display device using a light-emitting element as a display element will be described. A method for manufacturing the display device in this embodiment will be described in detail with reference to FIGS.

Silicon nitride oxide by a sputtering method, a PVD method (Physical Vapor Deposition), a low pressure CVD method (LPCVD method), or a CVD method (Chemical Vapor Deposition) such as a plasma CVD method as a base film over the substrate 100 having an insulating surface. A base film 101a is formed to 10 to 200 nm (preferably 50 to 150 nm) using the film, and a base film 101b is stacked to 50 to 200 nm (preferably 100 to 150 nm) using a silicon oxynitride film. Alternatively, heat-resistant polymers such as acrylic acid, methacrylic acid and derivatives thereof, polyimide, aromatic polyamide, polybenzimidazole, or siloxane resin may be used. Moreover, resin materials such as vinyl resins such as polyvinyl alcohol and polyvinyl butyral, epoxy resins, phenol resins, novolac resins, acrylic resins, melamine resins, and urethane resins may be used. Alternatively, an organic material such as benzocyclobutene, parylene, fluorinated arylene ether, or polyimide, a composition material containing a water-soluble homopolymer and a water-soluble copolymer, or the like may be used. Moreover, an oxazole resin can also be used, for example, photocurable polybenzoxazole or the like can be used.

Further, a droplet discharge method, a printing method (a method for forming a pattern such as screen printing or offset printing), a coating method such as a spin coating method, a dipping method, a dispenser method, or the like can also be used. In this embodiment, the base film 101a and the base film 101b are formed by a plasma CVD method. As the substrate 100, a glass substrate, a quartz substrate, a silicon substrate, a metal substrate, or a stainless substrate on which an insulating film is formed may be used. Further, a plastic substrate having heat resistance that can withstand the processing temperature of this embodiment may be used, or a flexible substrate such as a film may be used. As the plastic substrate, a substrate made of PET (polyethylene terephthalate), PEN (polyethylene naphthalate), or PES (polyethersulfone) can be used, and as the flexible substrate, a synthetic resin such as acrylic can be used. Since the display device manufactured in this embodiment has a structure in which light from the light-emitting element is extracted through the substrate 100, the substrate 100 needs to have a light-transmitting property.

As the base film, silicon oxide, silicon nitride, silicon oxynitride, silicon nitride oxide, or the like can be used, and a single layer or a laminated structure of two layers or three layers may be used.

Next, a semiconductor film is formed over the base film. The semiconductor film may be formed by various means (a sputtering method, an LPCVD method, a plasma CVD method, or the like) with a thickness of 25 to 200 nm (preferably 30 to 150 nm). In this embodiment mode, it is preferable to use a crystalline semiconductor film obtained by crystallizing an amorphous semiconductor film by laser crystallization.

In order to control the threshold voltage of the thin film transistor, the semiconductor film thus obtained may be doped with a trace amount of impurity element (boron or phosphorus). This doping of the impurity element may be performed on the amorphous semiconductor film before the crystallization step. When the impurity element is doped in the state of the amorphous semiconductor film, the impurity can be activated by heat treatment for subsequent crystallization. In addition, defects and the like generated during doping can be improved.

Next, the crystalline semiconductor film is etched into a desired shape to form a semiconductor layer.

As the etching process, either plasma etching (dry etching) or wet etching may be employed, but plasma etching is suitable for processing a large area substrate. As an etching gas, a fluorine-based gas such as CF ₄ or NF ₃ or a chlorine-based gas such as Cl ₂ or BCl ₃ may be used, and an inert gas such as He or Ar may be appropriately added. Further, if an atmospheric pressure discharge etching process is applied, a local electric discharge process is also possible, and it is not necessary to form a mask layer on the entire surface of the substrate.

In the present invention, a conductive layer for forming a wiring layer or an electrode layer, a mask layer for forming a predetermined pattern, or the like may be formed by a method capable of selectively forming a pattern such as a droplet discharge method. . A droplet discharge (ejection) method (also called an ink-jet method depending on the method) is a method in which a droplet of a composition prepared for a specific purpose is selectively ejected (ejection) to form a predetermined pattern (such as a conductive layer or a conductive layer). An insulating layer or the like can be formed. At this time, a process for controlling wettability and adhesion may be performed on the formation region. In addition, a method by which a pattern can be transferred or drawn, for example, a printing method (a method for forming a pattern such as screen printing or offset printing), a dispenser method, or the like can also be used.

In this embodiment mode, a resin material such as an epoxy resin, an acrylic resin, a phenol resin, a novolac resin, a melamine resin, or a urethane resin is used as a mask to be used. Also, a composition comprising an organic material such as benzocyclobutene, parylene, fluorinated arylene ether, translucent polyimide, a compound material obtained by polymerization of a siloxane polymer, a water-soluble homopolymer and a water-soluble copolymer Materials and the like can also be used. Alternatively, a commercially available resist material containing a photosensitizer may be used, for example, a positive resist, a negative resist, or the like may be used. When using the droplet discharge method, regardless of which material is used, the surface tension and viscosity are appropriately adjusted by adjusting the concentration of the solvent, adding a surfactant or the like.

A gate insulating layer 107 is formed to cover the semiconductor layer. The gate insulating layer is formed of an insulating film containing silicon with a thickness of 10 to 150 nm using a plasma CVD method or a sputtering method. The gate insulating layer may be formed of a known material such as silicon nitride, silicon oxide, silicon oxynitride, or silicon oxide or nitride material typified by silicon nitride oxide, and may be a stacked layer or a single layer. Further, the insulating layer may be a three-layer stack of a silicon nitride film, a silicon oxide film, and a silicon nitride film, or a stack of a single layer and two layers of a silicon oxynitride film.

Next, a gate electrode layer is formed over the gate insulating layer 107. The gate electrode layer can be formed by a technique such as sputtering, vapor deposition, or CVD. The gate electrode layer is an element selected from tantalum (Ta), tungsten (W), titanium (Ti), molybdenum (Mo), aluminum (Al), copper (Cu), chromium (Cr), neodymium (Nd), or What is necessary is just to form with the alloy material or compound material which has the said element as a main component. Alternatively, a semiconductor film typified by a polycrystalline silicon film doped with an impurity element such as phosphorus, or an AgPdCu alloy may be used for the gate electrode layer. The gate electrode layer may be a single layer or a stacked layer.

In this embodiment mode, the gate electrode layer is formed to have a tapered shape; however, the present invention is not limited thereto, and the gate electrode layer has a stacked structure, and only one layer has a tapered shape, and the other is anisotropic. You may have a vertical side surface by an etching. As in this embodiment, the taper angle may be different between the stacked gate electrode layers, or may be the same. By having a tapered shape, the coverage of a film stacked thereon is improved and defects are reduced, so that reliability is improved.

The gate insulating layer 107 may be slightly etched by an etching process when forming the gate electrode layer, and the film thickness may be reduced (so-called film reduction).

An impurity element is added to the semiconductor layer to form an impurity region. The impurity region can be a high concentration impurity region and a low concentration impurity region by controlling the concentration thereof. A thin film transistor having a low-concentration impurity region is referred to as an LDD (Lightly Doped Drain) structure. The low-concentration impurity region can be formed so as to overlap with the gate electrode. Such a thin film transistor is referred to as a GOLD (Gate Overlapped LDD) structure. The polarity of the thin film transistor is n-type by using phosphorus (P) or the like in the impurity region. When p-type is used, boron (B) or the like may be added.

In this embodiment, a region where the impurity region overlaps with the gate electrode layer through the gate insulating layer is referred to as a Lov region, and a region where the impurity region does not overlap with the gate electrode layer through the gate insulating layer is referred to as a Loff region. In FIG. 9, hatching and white background are shown in the impurity region, but this does not indicate that the impurity element is not added to the white background part, but the concentration distribution of the impurity element in this region is mask or doping. This is because it is possible to intuitively understand that the conditions are reflected. This also applies to other drawings in this specification.

In order to activate the impurity element, heat treatment, intense light irradiation, or laser light irradiation may be performed. Simultaneously with activation, plasma damage to the gate insulating layer and plasma damage to the interface between the gate insulating layer and the semiconductor layer can be recovered.

Next, a first interlayer insulating layer is formed to cover the gate electrode layer and the gate insulating layer. In this embodiment mode, a stacked structure of the insulating film 167 and the insulating film 168 is employed. As the insulating film 167 and the insulating film 168, a silicon nitride film, a silicon nitride oxide film, a silicon oxynitride film, a silicon oxide film, or the like using a sputtering method or plasma CVD can be used, and another insulating film containing silicon can be used. A single layer or a stacked structure of three or more layers may be used.

Further, a heat treatment is performed at 300 to 550 ° C. for 1 to 12 hours in a nitrogen atmosphere to perform a step of hydrogenating the semiconductor layer. Preferably, it carries out at 400-500 degreeC. This step is a step of terminating dangling bonds in the semiconductor layer with hydrogen contained in the insulating film 167 which is an interlayer insulating layer. In this embodiment, heat treatment is performed at 410 degrees (° C.).

In addition, as the insulating films 167 and 168, aluminum nitride (AlN), aluminum oxynitride (AlON), aluminum nitride oxide (AlNO) or aluminum oxide in which the nitrogen content is higher than the oxygen content, diamond like carbon (DLC) , Nitrogen-containing carbon (CN), polysilazane, and other materials including inorganic insulating materials. Further, a material containing siloxane may be used. Further, an organic insulating material may be used, and as the organic material, polyimide, acrylic, polyamide, polyimide amide, resist, or benzocyclobutene can be used. Moreover, an oxazole resin can also be used, for example, photocurable polybenzoxazole or the like can be used.

Next, contact holes (openings) that reach the semiconductor layers are formed in the insulating film 167, the insulating film 168, and the gate insulating layer 107 using a resist mask. A conductive film is formed so as to cover the opening, and the conductive film is etched to form a source electrode layer or a drain electrode layer that is electrically connected to a part of each source region or drain region. The source electrode layer or the drain electrode layer can be formed by forming a conductive film by a PVD method, a CVD method, an evaporation method, or the like and then etching the conductive film into a desired shape. In addition, a conductive layer can be selectively formed at a predetermined place by a droplet discharge method, a printing method, a dispenser method, an electroplating method, or the like. Furthermore, a reflow method or a damascene method may be used. The material of the source electrode layer or the drain electrode layer is Ag, Au, Cu, Ni, Pt, Pd, Ir, Rh, W, Al, Ta, Mo, Cd, Zn, Fe, Ti, Si, Ge, Zr, Ba Or a metal nitride thereof or a metal nitride thereof. Moreover, it is good also as these laminated structures.

Through the above steps, the peripheral driver circuit region 204 includes a thin film transistor 285 which is a p-channel thin film transistor having a p-type impurity region in the Lov region, and a thin film transistor 275 which is an n-channel thin film transistor having an n-channel impurity region in the Lov region. In 206, an active matrix substrate having a thin film transistor 265 which is a multi-channel n-channel thin film transistor having an n-type impurity region in a Loff region and a thin film transistor 245 which is a p-channel thin film transistor having a p-type impurity region in a Lov region is manufactured. Can do.

Without being limited to this embodiment mode, the thin film transistor may have a single gate structure in which one channel formation region is formed, a double gate structure in which two channel formation regions are formed, or a triple gate structure in which three channel formation regions are formed. The thin film transistor in the peripheral driver circuit region may have a single gate structure, a double gate structure, or a triple gate structure.

Next, an insulating film 181 is formed as a second interlayer insulating layer. In FIG. 9, there are a separation region 201 for separation by scribing, an external terminal connection region 202 that is an FPC attachment portion, a wiring region 203 that is a peripheral wiring region, a peripheral driver circuit region 204, and a pixel region 206. . The wiring region 203 is provided with wirings 179a and 179b, and the external terminal connection region 202 is provided with a terminal electrode layer 178 that is connected to an external terminal.

As the insulating film 181, silicon oxide, silicon nitride, silicon oxynitride, silicon nitride oxide, aluminum nitride (AlN), aluminum oxide containing nitrogen (also referred to as aluminum oxynitride) (AlON), aluminum nitride containing oxygen (aluminum nitride oxide) (Also) (AlNO), aluminum oxide, diamond-like carbon (DLC), nitrogen-containing carbon (CN), PSG (phosphorus glass), BPSG (phosphorus boron glass), alumina, and other inorganic insulating materials It is possible to form with a material. A siloxane resin may also be used. Further, an organic insulating material may be used, and the organic material may be either photosensitive or non-photosensitive, and polyimide, acrylic, polyamide, polyimide amide, resist or benzocyclobutene, polysilazane, low dielectric constant (Low− k) Materials can be used. Moreover, an oxazole resin can also be used, for example, photocurable polybenzoxazole or the like can be used. An interlayer insulating layer provided for planarization is required to have high heat resistance and high insulation and a high planarization rate. Therefore, a method for forming the insulating film 181 is represented by a spin coating method. It is preferable to use a coating method.

The insulating film 181 may employ other dipping methods, spray coating, doctor knife, roll coater, curtain coater, knife coater, CVD method, vapor deposition method, and the like. The insulating film 181 may be formed by a droplet discharge method. When the droplet discharge method is used, the material liquid can be saved. Further, a method capable of transferring or drawing a pattern, such as a droplet discharge method, for example, a printing method (a method for forming a pattern such as screen printing or offset printing), a dispenser method, or the like can be used.

A fine opening, that is, a contact hole is formed in the insulating film 181 in the pixel region 206.

Next, a first electrode layer 185 (also referred to as a pixel electrode layer) is formed so as to be in contact with the source electrode layer or the drain electrode layer. The first electrode layer 185 functions as an anode or a cathode and is an element selected from Ti, Ni, W, Cr, Pt, Zn, Sn, In, or Mo, or titanium nitride, TiSi _X N _Y , WSi _X , Tungsten nitride, WSi _X N _Y , NbN, or the like, a film mainly containing an alloy material or compound material containing the above elements as a main component, or a stacked film thereof may be used in a total film thickness range of 100 nm to 800 nm.

In this embodiment, a light-emitting element is used as a display element and light from the light-emitting element is extracted from the first electrode layer 185 side; thus, the first electrode layer 185 has a light-transmitting property. A transparent conductive film is formed as the first electrode layer 185, and the first electrode layer 185 is formed by etching into a desired shape.

In the present invention, a transparent conductive film made of a light-transmitting conductive material may be used for the first electrode layer 185 that is a light-transmitting electrode layer, indium oxide containing tungsten oxide, Indium zinc oxide containing tungsten oxide, indium oxide containing titanium oxide, indium tin oxide containing titanium oxide, or the like can be used. Needless to say, indium tin oxide (ITO), indium zinc oxide (IZO), indium tin oxide added with silicon oxide (ITSO), or the like can also be used.

Further, even when a material such as a metal film that does not have translucency is used, the first film thickness can be reduced by thinning (preferably about 5 nm to 30 nm) so that light can be transmitted. It becomes possible to emit light from the electrode layer 185. As the metal thin film that can be used for the first electrode layer 185, a conductive film made of titanium, tungsten, nickel, gold, platinum, silver, aluminum, magnesium, calcium, lithium, or an alloy thereof is used. Can do.

The first electrode layer 185 can be formed by an evaporation method, a sputtering method, a CVD method, a printing method, a dispenser method, a droplet discharge method, or the like. In this embodiment, the first electrode layer 185 is formed by a sputtering method using indium zinc oxide containing tungsten oxide. The first electrode layer 185 is preferably used in a total film thickness range of 100 nm to 800 nm.

The first electrode layer 185 may be wiped with a CMP method or a polyvinyl alcohol-based porous material and polished so that the surface thereof is planarized. Further, after polishing using the CMP method, the surface of the first electrode layer 185 may be subjected to ultraviolet irradiation, oxygen plasma treatment, or the like.

Heat treatment may be performed after the first electrode layer 185 is formed. By this heat treatment, moisture contained in the first electrode layer 185 is released. Therefore, the first electrode layer 185 does not cause degassing. Therefore, even when a light-emitting material that is easily deteriorated by moisture is formed over the first electrode layer, the light-emitting material is not deteriorated and the display device has high reliability. Can be produced.

Next, an insulating layer 186 (referred to as a partition wall, a barrier, or the like) is formed to cover the end portion of the first electrode layer 185 and the source or drain electrode layer.

As the insulating layer 186, silicon oxide, silicon nitride, silicon oxynitride, silicon nitride oxide, or the like can be used, and a single layer or a stacked structure of two layers or three layers may be used. As other materials for the insulating layer 186, aluminum nitride, aluminum oxynitride having an oxygen content higher than the nitrogen content, aluminum nitride oxide or aluminum oxide having a nitrogen content higher than the oxygen content, diamond-like carbon (DLC) ), Nitrogen-containing carbon, polysilazane, and other materials including inorganic insulating materials. A material containing siloxane may be used. Further, an organic insulating material may be used, and the organic material may be either photosensitive or non-photosensitive, and polyimide, acrylic, polyamide, polyimide amide, resist, benzocyclobutene, or polysilazane can be used. Moreover, an oxazole resin can also be used, for example, photocurable polybenzoxazole or the like can be used.

The insulating layer 186 is formed by a sputtering method, a PVD method (Physical Vapor Deposition), a low pressure CVD method (LPCVD method), a CVD method such as a plasma CVD method (Chemical Vapor Deposition), or a droplet discharge capable of selectively forming a pattern. It is also possible to use a method, a printing method capable of transferring or drawing a pattern (a method of forming a pattern such as screen printing or offset printing), a coating method such as a dispenser method, a spin coating method, or a dipping method.

As the etching process for processing into a desired shape, either plasma etching (dry etching) or wet etching may be employed. Plasma etching is suitable for processing large area substrates. As an etching gas, a fluorine-based gas such as CF ₄ or NF ₃ or a chlorine-based gas such as Cl ₂ or BCl ₃ may be used, and an inert gas such as He or Ar may be appropriately added. Further, if an atmospheric pressure discharge etching process is applied, a local electric discharge process is also possible, and it is not necessary to form a mask layer on the entire surface of the substrate.

In the connection region 205 illustrated in FIG. 9A, the wiring layer formed of the same material and in the same process as the second electrode layer is electrically connected to the wiring layer of the same process and the same material as the gate electrode layer. To do.

An electroluminescent layer 188 is formed over the first electrode layer 185. Although only one pixel is shown in FIG. 9, electroluminescent layers corresponding to each color of R (red), G (green), and B (blue) are separately formed in this embodiment.

Next, a second electrode layer 189 made of a conductive film is provided over the electroluminescent layer 188. As the second electrode layer 189, Al, Ag, Li, Ca, or an alloy or compound thereof such as MgAg, MgIn, AlLi, CaF ₂ , or calcium nitride may be used. Thus, a light-emitting element 190 including the first electrode layer 185, the electroluminescent layer 188, and the second electrode layer 189 is formed (see FIG. 9B).

In the display device of this embodiment mode illustrated in FIG. 9, light emitted from the light-emitting element 190 is transmitted through and emitted from the first electrode layer 185 side in the direction of the arrow in FIG.

In this embodiment, an insulating layer may be provided as a passivation film (a protective film) over the second electrode layer 189. Thus, it is effective to provide a passivation film so as to cover the second electrode layer 189. As the passivation film, silicon nitride, silicon oxide, silicon oxynitride, silicon nitride oxide, aluminum nitride, aluminum oxynitride, aluminum nitride oxide or aluminum oxide having a nitrogen content higher than the oxygen content, diamond-like carbon (DLC), The insulating film includes a nitrogen-containing carbon film, and a single layer or a combination of the insulating films can be used. Alternatively, a siloxane resin may be used.

At this time, it is preferable to use a film with good coverage as the passivation film, and it is effective to use a carbon film, particularly a DLC film. Since the DLC film can be formed in a temperature range from room temperature to 100 ° C., it can be easily formed over the electroluminescent layer 188 having low heat resistance. The DLC film is formed by a plasma CVD method (typically, an RF plasma CVD method, a microwave CVD method, an electron cyclotron resonance (ECR) CVD method, a hot filament CVD method, etc.), a combustion flame method, a sputtering method, or an ion beam evaporation method. It can be formed by laser vapor deposition. The reaction gas used for film formation was hydrogen gas and a hydrocarbon-based gas (for example, CH ₄ , C ₂ H ₂ , C ₆ H _6, etc.), ionized by glow discharge, and negative self-bias was applied. Films are formed by accelerated collision of ions with the cathode. The CN film may be formed using C ₂ H ₄ gas and N ₂ gas as reaction gases. The DLC film has a high blocking effect against oxygen and can suppress oxidation of the electroluminescent layer 188. Therefore, the problem that the electroluminescent layer 188 is oxidized during the subsequent sealing process can be prevented.

The substrate 100 over which the light-emitting element 190 is formed in this manner and the sealing substrate 195 are fixed with a sealant 192 to seal the light-emitting element (see FIG. 9). As the sealant 192, it is typically preferable to use a visible light curable resin, an ultraviolet curable resin, or a thermosetting resin. For example, bisphenol A type liquid resin, bisphenol A type solid resin, bromine-containing epoxy resin, bisphenol F type resin, bisphenol AD type resin, phenol type resin, cresol type resin, novolac type resin, cyclic aliphatic epoxy resin, epibis type epoxy Epoxy resins such as resins, glycidyl ester resins, glycidylamine resins, heterocyclic epoxy resins, and modified epoxy resins can be used. Note that a region surrounded by the sealant may be filled with a filler 193, or nitrogen or the like may be sealed by sealing in a nitrogen atmosphere. Since this embodiment mode is a bottom emission type, the filler 193 does not need to have translucency, but in the case of a structure in which light is extracted through the filler 193, the filler 193 needs to have translucency. Typically, a visible light curable, ultraviolet curable, or thermosetting epoxy resin may be used. Through the above steps, a display device having a display function using a light-emitting element in this embodiment is completed. Further, the filler can be dropped in a liquid state and filled in the display device. When a material having hygroscopicity such as a desiccant is used as the filler, a further water absorption effect can be obtained and deterioration of the element can be prevented.

A desiccant is installed in the EL display panel in order to prevent deterioration of the element due to moisture. In this embodiment mode, the desiccant is provided in a recess formed in the sealing substrate so as to surround the pixel region, and the thickness is not hindered. Further, since the desiccant is formed also in the region corresponding to the gate wiring layer and the area for forming the desiccant having a water absorbing function is wide, the water absorbing effect is high. Further, since the desiccant is formed on the gate wiring layer that does not contribute to light emission, the light extraction efficiency is not lowered.

Note that in this embodiment mode, a case where a light-emitting element is sealed with a glass substrate is shown; however, the sealing process is a process for protecting the light-emitting element from moisture and is mechanically sealed with a cover material. Either a method, a method of encapsulating with a thermosetting resin or an ultraviolet light curable resin, or a method of encapsulating with a thin film having a high barrier ability such as a metal oxide or a nitride is used. As the cover material, glass, ceramics, plastic, or metal can be used. However, when light is emitted to the cover material side, it must be translucent. In addition, the cover material and the substrate on which the light emitting element is formed are bonded together using a sealing material such as a thermosetting resin or an ultraviolet light curable resin, and the resin is cured by heat treatment or ultraviolet light irradiation treatment to form a sealed space. Form. It is also effective to provide a hygroscopic material typified by barium oxide in this sealed space. This hygroscopic material may be provided in contact with the sealing material, or may be provided on the partition wall or in the peripheral portion so as not to block light from the light emitting element. Further, the space between the cover material and the substrate on which the light emitting element is formed can be filled with a thermosetting resin or an ultraviolet light curable resin. In this case, it is effective to add a moisture absorbing material typified by barium oxide in the thermosetting resin or the ultraviolet light curable resin.

In the display device in FIG. 9 manufactured in this embodiment mode in FIG. 12, the source electrode layer or the drain electrode layer and the first electrode layer are not in direct contact with each other for electrical connection, but through the wiring layer. An example of connection is shown. In the display device in FIG. 12, the source electrode layer or the drain electrode layer of the thin film transistor for driving the light emitting element and the first electrode layer 395 are electrically connected to each other through the wiring layer 199. In FIG. 12, the first electrode layer 395 is connected to the wiring layer 199 so as to be partially stacked. However, the first electrode layer 395 is formed first, and the first electrode layer 395 is formed. The wiring layer 199 may be formed so as to be in contact with the top.

In this embodiment mode, the FPC 194 is connected to the terminal electrode layer 178 with the anisotropic conductive layer 196 in the external terminal connection region 202 so as to be electrically connected to the outside. In addition, as shown in FIG. 9A which is a top view of the display device, the display device manufactured in this embodiment includes a peripheral driver circuit region 204 having a signal line driver circuit and a peripheral driver circuit region 209. A peripheral driving circuit region 207 having a scanning line driving circuit and a peripheral driving circuit region 208 are provided.

In this embodiment mode, the circuit is formed as described above. However, the present invention is not limited to this, and an IC chip may be mounted as a peripheral driver circuit by the above-described COG method or TAB method. Further, the gate line driver circuit and the source line driver circuit may be plural or singular.

In the display device of the present invention, the screen display driving method is not particularly limited. For example, a dot sequential driving method, a line sequential driving method, a surface sequential driving method, or the like may be used. Typically, a line sequential driving method is used, and a time-division gray scale driving method or an area gray scale driving method may be used as appropriate. The video signal input to the source line of the display device may be an analog signal or a digital signal, and a drive circuit or the like may be designed in accordance with the video signal as appropriate.

Since the display device shown in FIGS. 9 and 12 is a bottom emission type, light is radiated from the substrate 100, so that the substrate 100 side is the viewing side. Therefore, a translucent substrate is used as the substrate 100, and an antireflection film 177 is provided on the outer side corresponding to the viewing side. The antireflection film 177 is an antireflection film having a plurality of convex portions on the surface, and the convex portions are conical in the present embodiment.

In addition to the conical shape, the convex portion may have a needle shape, a trapezoidal shape in which the tip of the cone is flat, or a dome shape with a rounded tip. Further, the antireflection film can be formed of a material whose refractive index changes from the surface toward the display screen instead of a uniform refractive index. For example, in the plurality of convex portions, the convex portion surface side is formed of a material having a refractive index equivalent to that of air, and has a structure that reduces reflection of the convex surface of external light incident on the convex portion more than air. On the other hand, a plurality of convex portions are formed of a material having a refractive index equivalent to that of the substrate as they approach the substrate side on the display screen side, and travel through the convex portions, and at the interface between the convex portions of light incident on the substrate and the substrate. To reduce the reflection of light. When a glass substrate is used as the substrate, the refractive index of air is smaller than that of the glass substrate, so that the convex portion is formed of a material having a lower refractive index on the surface (the tip portion if conical), and the bottom surface of the convex portion The refractive index may be increased from the conical tip portion toward the bottom surface as it is made of a material having a high refractive index as it approaches.

The display device having the antireflection film of this embodiment has a plurality of convex portions on the surface, and the reflected light of outside light is not reflected on the viewer side because the convex portion interface is not flat. Reflects to the convex part. Or it progresses between convex parts. The incident external light is partially transmitted through the convex portion, and the reflected light is incident on the adjacent convex portion again. Thus, the external light reflected by the convex interface repeatedly enters the other adjacent convex part.

That is, the number of external light incident on the display device that is incident on the antireflection film increases, so that the amount of light transmitted through the antireflection film increases. Therefore, the external light reflected on the viewer side is reduced, and the cause of lower visibility such as reflection can be prevented.

INDUSTRIAL APPLICABILITY The present invention can provide a display device with high visibility having a high antireflection function that can reduce reflection of external light by providing an antireflection film having a plurality of convex portions on the surface. Therefore, a display device with high image quality and high performance can be manufactured according to the present invention.

This embodiment mode can be freely combined with Embodiment Mode 1 described above.

(Embodiment 6)
Although a display device having a light-emitting element can be formed by applying the present invention, light emitted from the light-emitting element performs any one of bottom emission, top emission, and dual emission. In this embodiment, examples of a dual emission type and a top emission type will be described with reference to FIGS.

11 includes an element substrate 1600, a thin film transistor 1655, a thin film transistor 1665, a thin film transistor 1675, a thin film transistor 1685, a first electrode layer 1617, an electroluminescent layer 1619, a second electrode layer 1620, a filler 1622, and a sealant 1632. , Insulating film 1601a, insulating film 1601b, gate insulating layer 1610, insulating film 1611, insulating film 1612, insulating layer 1614, sealing substrate 1625, wiring layer 1633, terminal electrode layer 1681, anisotropic conductive layer 1682, FPC 1683, reflection The prevention films 1627a and 1627b are configured. The display device includes an external terminal connection region 232, a sealing region 233, a peripheral driver circuit region 234, and a pixel region 236. The filler 1622 can be formed by a dropping method in a liquid composition state. The element substrate 1600 on which the filler is formed and the sealing substrate 1625 are attached to each other by a dropping method to seal the light emitting display device.

The display device in FIG. 11 is a dual emission type, and has a structure in which light is emitted from both the element substrate 1600 side and the sealing substrate 1625 side in the direction of the arrow. Therefore, a light-transmitting electrode layer is used as the first electrode layer 1617 and the second electrode layer 1620.

In this embodiment mode, specifically, a transparent conductive film formed using a light-transmitting conductive material may be used for the first electrode layer 1617 and the second electrode layer 1620 which are light-transmitting electrode layers. Indium oxide containing tungsten oxide, indium zinc oxide containing tungsten oxide, indium oxide containing titanium oxide, indium tin oxide containing titanium oxide, or the like can be used. Needless to say, indium tin oxide (ITO), indium zinc oxide (IZO), indium tin oxide added with silicon oxide (ITSO), or the like can also be used.

Further, even when a material such as a metal film that does not have translucency is used, the first film thickness can be reduced by thinning (preferably about 5 nm to 30 nm) so that light can be transmitted. Light can be emitted from the electrode layer 1617 and the second electrode layer 1620 of the first electrode. In addition, examples of a metal thin film that can be used for the first electrode layer 1617 and the second electrode layer 1620 include titanium, tungsten, nickel, gold, platinum, silver, aluminum, magnesium, calcium, lithium, and alloys thereof. A conductive film can be used.

As described above, the display device in FIG. 11 has a structure in which light emitted from the light-emitting element 1605 passes through both the first electrode layer 1617 and the second electrode layer 1620 and emits light from both sides. .

The display device of FIG. 10 has a structure in which the top surface is emitted in the direction of the arrow. 10 includes an element substrate 1300, a thin film transistor 1355, a thin film transistor 1365, a thin film transistor 1375, a thin film transistor 1385, a wiring layer 1324, a first electrode layer 1317, an electroluminescent layer 1319, a second electrode layer 1320, and a protective film 1321. , Filler 1322, sealing material 1332, insulating film 1301a, insulating film 1301b, gate insulating layer 1310, insulating film 1311, insulating film 1312, insulating layer 1314, sealing substrate 1325, wiring layer 1333, terminal electrode layer 1381, anisotropic The conductive conductive layer 1382 and the FPC 1383 are included.

In the display device in FIGS. 11 and 10, the insulating layer stacked on the terminal electrode layer is removed by etching. As described above, the reliability is further improved when the insulating layer having moisture permeability is not provided around the terminal electrode layer. In FIG. 10, the display device includes an external terminal connection region 232, a sealing region 233, a peripheral driver circuit region 234, and a pixel region 236. The display device in FIG. 10 includes a wiring layer 1324 that is a reflective metal layer under the first electrode layer 1317 in the dual emission display device shown in FIG. A first electrode layer 1317 that is a transparent conductive film is formed over the wiring layer 1324. Since the wiring layer 1324 only needs to have reflectivity, a conductive film made of titanium, tungsten, nickel, gold, platinum, silver, copper, tantalum, molybdenum, aluminum, magnesium, calcium, lithium, or an alloy thereof, or the like May be used. A substance having high reflectivity in the visible light region is preferably used, and a titanium nitride film is used in this embodiment mode. Further, a conductive film may be used for the first electrode layer 1317. In that case, the wiring layer 1324 having reflectivity is not necessarily provided.

For the first electrode layer 1317 and the second electrode layer 1320, specifically, a transparent conductive film formed using a light-transmitting conductive material may be used. Indium oxide containing tungsten oxide or indium containing tungsten oxide may be used. Zinc oxide, indium oxide containing titanium oxide, indium tin oxide containing titanium oxide, or the like can be used. Needless to say, indium tin oxide (ITO), indium zinc oxide (IZO), indium tin oxide added with silicon oxide (ITSO), or the like can also be used.

Further, even if the material is a material such as a metal film that does not have translucency, the second film thickness can be reduced (preferably, about 5 nm to 30 nm) so that light can be transmitted. It becomes possible to emit light from the electrode layer 1320. As the metal thin film that can be used for the second electrode layer 1320, a conductive film made of titanium, tungsten, nickel, gold, platinum, silver, aluminum, magnesium, calcium, lithium, or an alloy thereof is used. Can do.

A pixel of a display device formed using a light-emitting element can be driven by a simple matrix method or an active matrix method. Further, either digital driving or analog driving can be applied.

A color filter (colored layer) may be formed on the sealing substrate. The color filter (colored layer) can be formed by an evaporation method or a droplet discharge method. When the color filter (colored layer) is used, high-definition display can be performed. This is because the color filter (colored layer) can be corrected so that a broad peak becomes a sharp peak in the emission spectrum of each RGB.

Full color display can be performed by forming a material exhibiting monochromatic light emission and combining a color filter and a color conversion layer. The color filter (colored layer) and the color conversion layer may be formed on, for example, a sealing substrate and attached to the element substrate.

Of course, monochromatic light emission may be displayed. For example, an area color type display device may be formed using monochromatic light emission. As the area color type, a passive matrix type display unit is suitable, and characters and symbols can be mainly displayed.

Since the display device illustrated in FIG. 11 is a dual emission type, light is emitted from both the element substrate 1600 and the sealing substrate 1625, so that both the element substrate 1600 side and the sealing substrate 1625 side are on the viewing side. Therefore, a light-transmitting substrate is used for both the element substrate 1600 and the sealing substrate 1625, and antireflection films 1627a and 1627b are provided on the outer side corresponding to the viewing side. On the other hand, since the display device illustrated in FIG. 10 is a top emission type, the sealing substrate 1325 on the viewing side is a light-transmitting substrate and an antireflection film 1327 is provided on the outside. The antireflection films 1627a, 1627b, and 1327 are antireflection films having a plurality of convex portions on the surface, and in the present embodiment, the convex portions are conical.

In addition to the conical shape, the convex portion may have a needle shape, a trapezoidal shape in which the tip of the cone is flat, or a dome shape with a rounded tip. Further, the antireflection film can be formed of a material whose refractive index changes from the surface toward the display screen instead of a uniform refractive index. For example, in the plurality of convex portions, the convex portion surface side is formed of a material having a refractive index equivalent to that of air, and has a structure that reduces reflection of the convex surface of external light incident on the convex portion more than air. On the other hand, a plurality of convex portions are formed of a material having a refractive index equivalent to that of the substrate as they approach the substrate side on the display screen side, and travel through the convex portions, and at the interface between the convex portions of light incident on the substrate and the substrate. To reduce the reflection of light. When a glass substrate is used as the substrate, the refractive index of air is smaller than that of the glass substrate, so that the convex portion is formed of a material having a lower refractive index on the surface (the tip portion if conical), and the bottom surface of the convex portion The refractive index may be increased from the conical tip portion toward the bottom surface as it is made of a material having a high refractive index as it approaches.

The display device having the antireflection film of this embodiment has a plurality of convex portions on the surface, and the reflected light of outside light is not reflected on the viewer side because the convex portion interface is not flat. Reflects to the convex part. Or it progresses between convex parts. The incident external light is partially transmitted through the convex portion, and the reflected light is incident on the adjacent convex portion again. Thus, the external light reflected by the convex interface repeatedly enters the other adjacent convex part.

That is, the number of external light incident on the display device that is incident on the antireflection film increases, so that the amount of light transmitted through the antireflection film increases. Therefore, the external light reflected on the viewer side is reduced, and the cause of lower visibility such as reflection can be prevented.

INDUSTRIAL APPLICABILITY The present invention can provide a display device with high visibility having a high antireflection function that can reduce reflection of external light by providing an antireflection film having a plurality of convex portions on the surface. Therefore, a display device with high image quality and high performance can be manufactured according to the present invention.

This embodiment mode can be freely combined with Embodiment Mode 1 described above.

(Embodiment 7)
In this embodiment mode, an example of a display device which has an antireflection function capable of further reducing reflection of external light and aims to provide excellent visibility will be described. Specifically, a light-emitting display device using a light-emitting element as a display element will be described.

In this embodiment mode, a structure of a light-emitting element that can be used as a display element of the display device of the present invention will be described with reference to FIGS.

  FIG. 22 shows an element structure of a light-emitting element, in which an electroluminescent layer 860 formed by mixing an organic compound and an inorganic compound is sandwiched between a first electrode layer 870 and a second electrode layer 850. It is. The electroluminescent layer 860 includes a first layer 804, a second layer 803, and a third layer 802 as shown in the drawing, and particularly has a great feature in the first layer 804 and the third layer 802. .

  First, the first layer 804 is a layer that has a function of transporting holes to the second layer 803, and includes a first organic compound and a first organic electron-accepting property with respect to the first organic compound. It is a structure containing an inorganic compound. What is important is not simply that the first organic compound and the first inorganic compound are mixed, but the first inorganic compound exhibits an electron accepting property with respect to the first organic compound. By adopting such a configuration, many hole carriers are generated in the first organic compound which has essentially no intrinsic carrier, and exhibits extremely excellent hole injection and hole transport properties.

  Therefore, the first layer 804 has not only effects (such as improved heat resistance) that are considered to be obtained by mixing an inorganic compound, but also excellent conductivity (in particular, in the first layer 804, hole injection). And transportability) can also be obtained. This is an effect that cannot be obtained with a conventional hole transport layer in which an organic compound and an inorganic compound that do not have an electronic interaction with each other are simply mixed. Due to this effect, the drive voltage can be made lower than in the prior art. Further, since the first layer 804 can be thickened without causing an increase in driving voltage, a short circuit of an element due to dust or the like can be suppressed.

By the way, as described above, since hole carriers are generated in the first organic compound, the first organic compound is preferably a hole-transporting organic compound. Examples of the hole transporting organic compound include phthalocyanine (abbreviation: H ₂ Pc), copper phthalocyanine (abbreviation: CuPc), vanadyl phthalocyanine (abbreviation: VOPc), 4,4 ′, 4 ″ -tris (N, N -Diphenylamino) triphenylamine (abbreviation: TDATA), 4,4 ′, 4 ″ -tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine (abbreviation: MTDATA), 1,3 , 5-tris [N, N-di (m-tolyl) amino] benzene (abbreviation: m-MTDAB), N, N′-diphenyl-N, N′-bis (3-methylphenyl) -1,1 ′ -Biphenyl-4,4'-diamine (abbreviation: TPD), 4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (abbreviation: NPB), 4,4'-bis {N -[4-di m-tolyl) amino] phenyl-N-phenylamino} biphenyl (abbreviation: DNTPD), 4,4 ′, 4 ″ -tris (N-carbazolyl) triphenylamine (abbreviation: TCTA), and the like. It is not limited to. Among the above-mentioned compounds, aromatic amine compounds represented by TDATA, MTDATA, m-MTDAB, TPD, NPB, DNTPD, TCTA, etc. are likely to generate hole carriers and are suitable as the first organic compound. A group.

  On the other hand, the first inorganic compound may be anything as long as it can easily receive electrons from the first organic compound, and various metal oxides or metal nitrides can be used. Any transition metal oxide belonging to Group 12 is preferable because it easily exhibits electron acceptability. Specific examples include titanium oxide, zirconium oxide, vanadium oxide, molybdenum oxide, tungsten oxide, rhenium oxide, ruthenium oxide, and zinc oxide. Among the metal oxides described above, any of the transition metal oxides in Groups 4 to 8 of the periodic table has a high electron accepting property and is a preferred group. Vanadium oxide, molybdenum oxide, tungsten oxide, and rhenium oxide are particularly preferable because they can be vacuum-deposited and are easy to handle.

  Note that the first layer 804 may be formed by stacking a plurality of layers to which the above-described combination of an organic compound and an inorganic compound is applied. Moreover, other organic compounds or other inorganic compounds may be further contained.

  Next, the third layer 802 will be described. The third layer 802 is a layer having a function of transporting electrons to the second layer 803, and includes at least a third organic compound and a third inorganic compound that exhibits an electron donating property with respect to the third organic compound. It is the structure containing these. What is important is not that the third organic compound and the third inorganic compound are merely mixed, but that the third inorganic compound exhibits an electron donating property with respect to the third organic compound. By adopting such a structure, many electron carriers are generated in the third organic compound which has essentially no intrinsic carrier, and exhibits extremely excellent electron injection properties and electron transport properties.

  Therefore, the third layer 802 has not only an effect (such as improvement in heat resistance) considered to be obtained by mixing an inorganic compound but also excellent conductivity (especially in the third layer 802, electron injection). And transportability) can also be obtained. This is an effect that cannot be obtained with a conventional electron transport layer in which an organic compound and an inorganic compound that do not have an electronic interaction with each other are simply mixed. Due to this effect, the drive voltage can be made lower than in the prior art. In addition, since the third layer 802 can be thickened without causing an increase in driving voltage, a short circuit of an element due to dust or the like can be suppressed.

By the way, as described above, since an electron carrier is generated in the third organic compound, the third organic compound is preferably an electron-transporting organic compound. Examples of the electron-transporting organic compound include tris (8-quinolinolato) aluminum (abbreviation: Alq ₃ ), tris (4-methyl-8-quinolinolato) aluminum (abbreviation: Almq ₃ ), bis (10-hydroxybenzo [ h] -quinolinato) beryllium (abbreviation: BeBq ₂ ), bis (2-methyl-8-quinolinolato) (4-phenylphenolato) aluminum (abbreviation: BAlq), bis [2- (2′-hydroxyphenyl) benzoxa Zolato] zinc (abbreviation: Zn (BOX) ₂ ), bis [2- (2′-hydroxyphenyl) benzothiazolate] zinc (abbreviation: Zn (BTZ) ₂ ), bathophenanthroline (abbreviation: BPhen), bathocuproin (abbreviation: BCP), 2- (4-biphenylyl) -5- (4-tert-butylphenyl)- , 3,4-oxadiazole (abbreviation: PBD), 1,3-bis [5- (4-tert-butylphenyl) -1,3,4-oxadiazol-2-yl] benzene (abbreviation: OXD) -7), 2,2 ′, 2 ″-(1,3,5-benzenetriyl) -tris (1-phenyl-1H-benzimidazole) (abbreviation: TPBI), 3- (4-biphenylyl)- 4-phenyl-5- (4-tert-butylphenyl) -1,2,4-triazole (abbreviation: TAZ), 3- (4-biphenylyl) -4- (4-ethylphenyl) -5- (4- tert-butylphenyl) -1,2,4-triazole (abbreviation: p-EtTAZ) and the like, but are not limited thereto. Among the compounds described above, a chelate metal complex having a chelate ligand containing an aromatic ring typified by Alq ₃ , Almq ₃ , BeBq ₂ , BAlq, Zn (BOX) ₂ , Zn (BTZ) ₂ , Organic compounds having a phenanthroline skeleton typified by BPhen, BCP, etc., and organic compounds having an oxadiazole skeleton typified by PBD, OXD-7, etc., are likely to generate electron carriers and are suitable as a third organic compound. Compound group.

  On the other hand, the third inorganic compound may be anything as long as it easily gives electrons to the third organic compound, and various metal oxides or metal nitrides can be used. Earth metal oxides, rare earth metal oxides, alkali metal nitrides, alkaline earth metal nitrides, and rare earth metal nitrides are preferable because they easily exhibit electron donating properties. Specific examples include lithium oxide, strontium oxide, barium oxide, erbium oxide, lithium nitride, magnesium nitride, calcium nitride, yttrium nitride, and lanthanum nitride. In particular, lithium oxide, barium oxide, lithium nitride, magnesium nitride, and calcium nitride are preferable because they can be vacuum-deposited and are easy to handle.

  Note that the third layer 802 may be formed by stacking a plurality of layers to which the above-described combination of an organic compound and an inorganic compound is applied. Moreover, other organic compounds or other inorganic compounds may be further contained.

  Next, the second layer 803 will be described. The second layer 803 is a layer having a light emitting function and includes a light emitting second organic compound. Moreover, the structure containing a 2nd inorganic compound may be sufficient. The second layer 803 can be formed using various light-emitting organic compounds and inorganic compounds. However, since the second layer 803 is less likely to flow current than the first layer 804 and the third layer 802, the thickness is preferably about 10 nm to 100 nm.

The second organic compound is not particularly limited as long as it is a luminescent organic compound. For example, 9,10-di (2-naphthyl) anthracene (abbreviation: DNA), 9,10-di (2 -Naphthyl) -2-tert-butylanthracene (abbreviation: t-BuDNA), 4,4'-bis (2,2-diphenylvinyl) biphenyl (abbreviation: DPVBi), coumarin 30, coumarin 6, coumarin 545, coumarin 545T , Perylene, rubrene, periflanthene, 2,5,8,11-tetra (tert-butyl) perylene (abbreviation: TBP), 9,10-diphenylanthracene (abbreviation: DPA), 5,12-diphenyltetracene, 4- ( Dicyanomethylene) -2-methyl- [p- (dimethylamino) styryl] -4H-pyran (abbreviation: DCM1), 4- (di Cyanomethylene) -2-methyl-6- [2- (julolidin-9-yl) ethenyl] -4H-pyran (abbreviation: DCM2), 4- (dicyanomethylene) -2,6-bis [p- (dimethylamino) ) Styryl] -4H-pyran (abbreviation: BisDCM) and the like. In addition, bis [2- (4 ′, 6′-difluorophenyl) pyridinato-N, C ^{2 ′} ] iridium (picolinate) (abbreviation: FIrpic), bis {2- [3 ′, 5′-bis (trifluoromethyl) ) Phenyl] pyridinato-N, C ^{2 ′} } iridium (picolinate) (abbreviation: Ir (CF ₃ ppy) ₂ (pic)), tris (2-phenylpyridinato-N, C ^{2 ′} ) iridium (abbreviation: Ir (Ppy) ₃ ), bis (2-phenylpyridinato-N, C ^{2 ′} ) iridium (acetylacetonate) (abbreviation: Ir (ppy) ₂ (acac)), bis [2- (2′-thienyl) pyridinato -N, C ^{3 ']} iridium (acetylacetonate) _{(abbreviation: Ir (thp) 2 (acac} )), bis (2-phenylquinolinato--N, C ^2') iridium (Asechirua Tonato) _{(abbreviation: Ir (pq) 2 (acac} )), bis [2- (2'-benzothienyl) pyridinato -N, C ^{3 ']} iridium (acetylacetonate) (abbreviation: Ir _(btp) 2 (acac A compound capable of emitting phosphorescence such as)) can also be used.

For the second layer 803, a triplet excitation material containing a metal complex or the like may be used in addition to the singlet excitation light-emitting material. For example, among red light emitting pixels, green light emitting pixels, and blue light emitting pixels, a red light emitting pixel having a relatively short luminance half time is formed of a triplet excitation light emitting material, and the other A singlet excited luminescent material is used. The triplet excited luminescent material has a feature that the light emission efficiency is good, so that less power is required to obtain the same luminance. That is, when applied to a red pixel, the amount of current flowing through the light emitting element can be reduced, so that reliability can be improved. As a reduction in power consumption, a red light-emitting pixel and a green light-emitting pixel may be formed using a triplet excitation light-emitting material, and a blue light-emitting pixel may be formed using a singlet excitation light-emitting material. By forming a green light-emitting element having high human visibility with a triplet excited light-emitting material, power consumption can be further reduced.

Further, in the second layer 803, not only the second organic compound that emits light but also other organic compounds may be added. Examples of the organic compound that can be added include TDATA, MTDATA, m-MTDAB, TPD, NPB, DNTPD, TCTA, Alq ₃ , Almq ₃ , BeBq ₂ , BAlq, Zn (BOX) ₂ , and Zn (BTZ) described above. ₂ , BPhen, BCP, PBD, OXD-7, TPBI, TAZ, p-EtTAZ, DNA, t-BuDNA, DPVBi, etc., 4,4′-bis (N-carbazolyl) biphenyl (abbreviation: CBP), 1 , 3,5-tris [4- (N-carbazolyl) phenyl] benzene (abbreviation: TCPB) can be used, but is not limited thereto. In addition, the organic compound added in addition to the second organic compound in this way has an excitation energy larger than the excitation energy of the second organic compound in order to efficiently emit the second organic compound, and the second organic compound. It is preferable to add more than the organic compound (by this, concentration quenching of the second organic compound can be prevented). Or as another function, you may show light emission with a 2nd organic compound (Thereby, white light emission etc. are also attained).

    The second layer 803 may have a structure in which a light emitting layer having a different emission wavelength band is formed for each pixel to perform color display. Typically, a light emitting layer corresponding to each color of R (red), G (green), and B (blue) is formed. In this case as well, it is possible to improve color purity and prevent mirror reflection (reflection) of the pixel portion by providing a filter that transmits light in the emission wavelength band on the light emission side of the pixel. Can do. By providing the filter, it is possible to omit a circularly polarizing plate that has been conventionally required, and it is possible to eliminate the loss of light emitted from the light emitting layer. Furthermore, a change in color tone that occurs when the pixel portion (display screen) is viewed obliquely can be reduced.

    The material that can be used for the second layer 803 may be a low molecular weight organic light emitting material or a high molecular weight organic light emitting material. The polymer organic light emitting material has higher physical strength and higher device durability than the low molecular weight material. In addition, since the film can be formed by coating, the device can be manufactured relatively easily.

    Since the light emission color is determined by the material for forming the light emitting layer, a light emitting element exhibiting desired light emission can be formed by selecting these materials. Examples of the polymer electroluminescent material that can be used for forming the light emitting layer include polyparaphenylene vinylene, polyparaphenylene, polythiophene, and polyfluorene.

    Examples of the polyparaphenylene vinylene include poly (paraphenylene vinylene) [PPV] derivatives, poly (2,5-dialkoxy-1,4-phenylene vinylene) [RO-PPV], poly (2- (2′- Ethyl-hexoxy) -5-methoxy-1,4-phenylenevinylene) [MEH-PPV], poly (2- (dialkoxyphenyl) -1,4-phenylenevinylene) [ROPh-PPV] and the like. Examples of polyparaphenylene include derivatives of polyparaphenylene [PPP], poly (2,5-dialkoxy-1,4-phenylene) [RO-PPP], poly (2,5-dihexoxy-1,4-phenylene). ) And the like. The polythiophene series includes polythiophene [PT] derivatives, poly (3-alkylthiophene) [PAT], poly (3-hexylthiophene) [PHT], poly (3-cyclohexylthiophene) [PCHT], poly (3-cyclohexyl). -4-methylthiophene) [PCHMT], poly (3,4-dicyclohexylthiophene) [PDCHT], poly [3- (4-octylphenyl) -thiophene] [POPT], poly [3- (4-octylphenyl) -2,2 bithiophene] [PTOPT] and the like. Examples of the polyfluorene series include polyfluorene [PF] derivatives, poly (9,9-dialkylfluorene) [PDAF], poly (9,9-dioctylfluorene) [PDOF], and the like.

  The second inorganic compound may be any inorganic compound as long as it is difficult to quench the light emission of the second organic compound, and various metal oxides and metal nitrides can be used. In particular, a metal oxide of Group 13 or Group 14 of the periodic table is preferable because it is difficult to quench the light emission of the second organic compound, and specifically, aluminum oxide, gallium oxide, silicon oxide, and germanium oxide are preferable. . However, it is not limited to these.

  Note that the second layer 803 may be formed by stacking a plurality of layers to which the above-described combination of an organic compound and an inorganic compound is applied. Moreover, other organic compounds or other inorganic compounds may be further contained. The layer structure of the light-emitting layer can be changed, and instead of having a specific electron injection region or light-emitting region, an electrode layer for this purpose is provided, or a light-emitting material is dispersed. Modifications can be made without departing from the spirit of the present invention.

    A light-emitting element formed using the above materials emits light by being forward-biased. A pixel of a display device formed using a light-emitting element can be driven by a simple matrix method or an active matrix method. In any case, each pixel emits light by applying a forward bias at a specific timing, but is in a non-light emitting state for a certain period. By applying a reverse bias during this non-light emitting time, the reliability of the light emitting element can be improved. The light emitting element has a degradation mode in which the light emission intensity decreases under a constant driving condition and a degradation mode in which the non-light emitting area is enlarged in the pixel and the luminance is apparently decreased. However, alternating current that applies a bias in the forward and reverse directions. By performing a typical drive, the progress of deterioration can be delayed, and the reliability of the light-emitting display device can be improved. Further, either digital driving or analog driving can be applied.

    Therefore, a color filter (colored layer) may be formed on the sealing substrate. The color filter (colored layer) can be formed by an evaporation method or a droplet discharge method. When the color filter (colored layer) is used, high-definition display can be performed. This is because the color filter (colored layer) can be corrected so that a broad peak becomes a sharp peak in the emission spectrum of each RGB.

    Full color display can be performed by forming a material exhibiting monochromatic light emission and combining a color filter and a color conversion layer. The color filter (colored layer) and the color conversion layer may be formed on, for example, a sealing substrate and attached to the element substrate.

    Of course, monochromatic light emission may be displayed. For example, an area color type display device may be formed using monochromatic light emission. As the area color type, a passive matrix type display unit is suitable, and characters and symbols can be mainly displayed.

  The materials of the first electrode layer 870 and the second electrode layer 850 need to be selected in consideration of the work function, and both the first electrode layer 870 and the second electrode layer 850 are anodes depending on the pixel structure. Or a cathode. In the case where the polarity of the driving thin film transistor is a p-channel type, the first electrode layer 870 may be an anode and the second electrode layer 850 may be a cathode as illustrated in FIG. In the case where the polarity of the driving thin film transistor is an n-channel type, it is preferable that the first electrode layer 870 be a cathode and the second electrode layer 850 be an anode as shown in FIG. Materials that can be used for the first electrode layer 870 and the second electrode layer 850 are described. In the case where the first electrode layer 870 and the second electrode layer 850 function as anodes, a material having a high work function (specifically, a material of 4.5 eV or more) is preferable, and the first electrode layer and the second electrode In the case where the layer 850 functions as a cathode, a material having a low work function (specifically, a material having a value of 3.5 eV or less) is preferable. However, since the hole injection and hole transport characteristics of the first layer 804 and the electron injection and electron transport characteristics of the third layer 802 are excellent, both the first electrode layer 870 and the second electrode layer 850 are Various materials can be used with almost no work function limitation.

22A and 22B has a structure in which light is extracted from the first electrode layer 870, the second electrode layer 850 does not necessarily have a light-transmitting property. As the second electrode layer 850, an element selected from Ti, Ni, W, Cr, Pt, Zn, Sn, In, Ta, Al, Cu, Au, Ag, Mg, Ca, Li, or Mo, or nitriding A film mainly composed of an alloy material or a compound material mainly composed of the above elements such as titanium, TiSi _X N _Y , WSi _X , tungsten nitride, WSi _X N _Y , NbN or the like, or a laminated film thereof having a total film thickness of 100 nm to It may be used in the range of 800 nm.

    The second electrode layer 850 can be formed by an evaporation method, a sputtering method, a CVD method, a printing method, a dispenser method, a droplet discharge method, or the like.

    In addition, when a light-transmitting conductive material such as a material used for the first electrode layer 870 is used for the second electrode layer 850, light is extracted from the second electrode layer 850, so that the light-emitting element can emit light. The emitted light may have a dual emission structure in which both the first electrode layer 870 and the second electrode layer 850 are emitted.

  Note that the light-emitting element of the present invention has various variations by changing types of the first electrode layer 870 and the second electrode layer 850.

  FIG. 22B illustrates a case where the electroluminescent layer 860 includes the third layer 802, the second layer 803, and the first layer 804 in this order from the first electrode layer 870 side.

  As described above, in the light-emitting element of the present invention, the electric field in which the layer sandwiched between the first electrode layer 870 and the second electrode layer 850 includes a layer in which an organic compound and an inorganic compound are combined is included. The light emitting layer 860 is formed. Then, by mixing the organic compound and the inorganic compound, there are provided layers (that is, the first layer 804 and the third layer 802) that can obtain functions of high carrier injection and carrier transport that cannot be obtained independently. This is an organic and inorganic composite light emitting element. In addition, when the first layer 804 and the third layer 802 are provided on the first electrode layer 870 side, the first layer 804 and the third layer 802 need to be a layer in which an organic compound and an inorganic compound are combined. When provided on the 850 side, only an organic compound or an inorganic compound may be used.

  Note that although the electroluminescent layer 860 is a layer in which an organic compound and an inorganic compound are mixed, various known methods can be used as a formation method thereof. For example, there is a technique in which both an organic compound and an inorganic compound are evaporated by resistance heating and co-evaporated. In addition, while the organic compound is evaporated by resistance heating, the inorganic compound may be evaporated by electron beam (EB) and co-evaporated. Further, there is a method of evaporating the organic compound by resistance heating and simultaneously sputtering the inorganic compound and depositing both at the same time. In addition, the film may be formed by a wet method.

  Similarly, for the first electrode layer 870 and the second electrode layer 850, a vapor deposition method using resistance heating, an EB vapor deposition method, a sputtering method, a wet method, or the like can be used.

    FIG. 22C illustrates a structure in which a reflective electrode layer is used for the first electrode layer 870 and a light-transmitting electrode layer is used for the second electrode layer 850 in FIG. Light emitted from the element is reflected by the first electrode layer 870 and transmitted through the second electrode layer 850 to be emitted. Similarly, in FIG. 22D, a reflective electrode layer is used for the first electrode layer 870 and a light-transmitting electrode layer is used for the second electrode layer 850 in FIG. 22B. The light emitted from the light emitting element is reflected by the first electrode layer 870 and is transmitted through the second electrode layer 850 and emitted.

This embodiment mode can be freely combined with the embodiment mode of the display device having the above light-emitting element.

In the display device of the present embodiment, since the antireflection film having a plurality of convex portions is provided on the display device display screen surface, the number of times of entering the antireflection film among the external light incident on the display device is increased. The amount of light transmitted through the antireflection film increases. Therefore, the external light reflected on the viewer side is reduced, and the cause of lower visibility such as reflection can be prevented.

INDUSTRIAL APPLICABILITY The present invention can provide a display device with high visibility having a high antireflection function that can reduce reflection of external light by providing an antireflection film having a plurality of convex portions on the surface. Therefore, a display device with high image quality and high performance can be manufactured according to the present invention.

This embodiment mode can be freely combined with any of Embodiment Modes 1 to 3, 5, and 6 as appropriate.

(Embodiment 8)
In this embodiment mode, an example of a display device which has an antireflection function capable of further reducing reflection of external light and aims to provide excellent visibility will be described. Specifically, a light-emitting display device using a light-emitting element as a display element will be described. In this embodiment mode, structures of light-emitting elements that can be used as display elements of the display device of the present invention will be described with reference to FIGS.

A light-emitting element utilizing electroluminescence is distinguished depending on whether the light-emitting material is an organic compound or an inorganic compound. Generally, the former is called an organic EL element and the latter is called an inorganic EL element.

Inorganic EL elements are classified into a dispersion-type inorganic EL element and a thin-film inorganic EL element depending on the element structure. The former has an electroluminescent layer in which particles of a luminescent material are dispersed in a binder, and the latter has an electroluminescent layer made of a thin film of luminescent material, but is accelerated by a high electric field. This is common in that it requires more electrons. Note that the obtained light emission mechanism includes donor-acceptor recombination light emission using a donor level and an acceptor level, and localized light emission using inner-shell electron transition of a metal ion. In general, the dispersion-type inorganic EL element often has donor-acceptor recombination light emission, and the thin-film inorganic EL element often has localized light emission.

A light-emitting material that can be used in the present invention includes a base material and an impurity element serving as a light emission center. By changing the impurity element to be contained, light emission of various colors can be obtained. As a method for manufacturing the light-emitting material, various methods such as a solid phase method and a liquid phase method (coprecipitation method) can be used. Also, spray pyrolysis method, metathesis method, precursor thermal decomposition method, reverse micelle method, method combining these methods with high temperature firing, liquid phase method such as freeze-drying method, etc. can be used.

The solid phase method is a method in which a base material and an impurity element or a compound containing the impurity element are weighed, mixed in a mortar, heated and fired in an electric furnace, reacted, and the base material contains the impurity element. The firing temperature is preferably 700 to 1500 ° C. This is because the solid phase reaction does not proceed when the temperature is too low, and the base material is decomposed when the temperature is too high. In addition, although baking may be performed in a powder state, it is preferable to perform baking in a pellet state. Although firing at a relatively high temperature is required, it is a simple method, so it has high productivity and is suitable for mass production.

The liquid phase method (coprecipitation method) is a method in which a base material or a compound containing the base material and an impurity element or a compound containing the impurity element are reacted in a solution, dried, and then fired. The particles of the luminescent material are uniformly distributed, and the reaction can proceed even at a low firing temperature with a small particle size.

As a base material used for the light-emitting material, sulfide, oxide, or nitride can be used. Examples of the sulfide include zinc sulfide (ZnS), cadmium sulfide (CdS), calcium sulfide (CaS), yttrium sulfide (Y ₂ S ₃ ), gallium sulfide (Ga ₂ S ₃ ), strontium sulfide (SrS), sulfide. Barium (BaS) or the like can be used. As the oxide, for example, zinc oxide (ZnO), yttrium oxide (Y ₂ O ₃ ), or the like can be used. As the nitride, for example, aluminum nitride (AlN), gallium nitride (GaN), indium nitride (InN), or the like can be used. Furthermore, zinc selenide (ZnSe), zinc telluride (ZnTe), and the like can also be used, and calcium sulfide-gallium sulfide (CaGa ₂ S ₄ ), strontium sulfide-gallium sulfide (SrGa ₂ S ₄ ), barium sulfide-gallium (BaGa). _It may be a ternary mixed crystal such as ₂ S ₄ ).

As emission centers of localized emission, manganese (Mn), copper (Cu), samarium (Sm), terbium (Tb), erbium (Er), thulium (Tm), europium (Eu), cerium (Ce), praseodymium (Pr) or the like can be used. Note that a halogen element such as fluorine (F) or chlorine (Cl) may be added. The halogen element can also function as charge compensation.

On the other hand, a light-emitting material containing a first impurity element that forms a donor level and a second impurity element that forms an acceptor level can be used as the emission center of donor-acceptor recombination light emission. As the first impurity element, for example, fluorine (F), chlorine (Cl), aluminum (Al), or the like can be used. For example, copper (Cu), silver (Ag), or the like can be used as the second impurity element.

In the case where a light-emitting material for donor-acceptor recombination light emission is synthesized using a solid-phase method, a base material, a first impurity element or a compound containing the first impurity element, a second impurity element, or a second impurity element Each compound containing an impurity element is weighed and mixed in a mortar, and then heated and fired in an electric furnace. As the base material, the above-described base material can be used, and examples of the first impurity element or the compound containing the first impurity element include fluorine (F), chlorine (Cl), and aluminum sulfide (Al ₂ S). ₃ ) or the like, and examples of the second impurity element or the compound containing the second impurity element include copper (Cu), silver (Ag), copper sulfide (Cu ₂ S), and silver sulfide (Ag). ₂ S) or the like can be used. The firing temperature is preferably 700 to 1500 ° C. This is because the solid phase reaction does not proceed when the temperature is too low, and the base material is decomposed when the temperature is too high. In addition, although baking may be performed in a powder state, it is preferable to perform baking in a pellet state.

In addition, as an impurity element in the case of using a solid phase reaction, a compound including a first impurity element and a second impurity element may be used in combination. In this case, since the impurity element is easily diffused and the solid-phase reaction easily proceeds, a uniform light emitting material can be obtained. Further, since no extra impurity element is contained, a light-emitting material with high purity can be obtained. As the compound including the first impurity element and the second impurity element, for example, copper chloride (CuCl), silver chloride (AgCl), or the like can be used.

Note that the concentration of these impurity elements may be 0.01 to 10 atom% with respect to the base material, and is preferably in the range of 0.05 to 5 atom%.

In the case of a thin-film inorganic EL element, the electroluminescent layer is a layer containing the above-described luminescent material, and is a physical vapor deposition method such as a resistance vapor deposition method, a vacuum vapor deposition method such as an electron beam vapor deposition (EB vapor deposition) method, or a sputtering method. (PVD), metal organic chemical vapor deposition (CVD), chemical vapor deposition (CVD) such as hydride transport low pressure CVD, atomic layer epitaxy (ALE), or the like.

FIGS. 23A to 23C illustrate an example of a thin-film inorganic EL element that can be used as a light-emitting element. 23A to 23C, the light-emitting element includes a first electrode layer 50, an electroluminescent layer 52, and a second electrode layer 53.

The light-emitting element illustrated in FIGS. 23B and 23C has a structure in which an insulating layer is provided between the electrode layer and the electroluminescent layer in the light-emitting element in FIG. The light-emitting element illustrated in FIG. 23B includes an insulating layer 54 between the first electrode layer 50 and the electroluminescent layer 52, and the light-emitting element illustrated in FIG. 23C includes the first electrode layer 50. And an electroluminescent layer 52, and an insulating layer 54 b is provided between the second electrode layer 53 and the electroluminescent layer 52. Thus, the insulating layer may be provided only between one of the pair of electrode layers sandwiching the electroluminescent layer, or may be provided between both. Further, the insulating layer may be a single layer or a stacked layer including a plurality of layers.

23B, the insulating layer 54 is provided so as to be in contact with the first electrode layer 50. However, the order of the insulating layer and the electroluminescent layer is reversed so as to be in contact with the second electrode layer 53. An insulating layer 54 may be provided.

In the case of a dispersion-type inorganic EL element, a particulate light emitting material is dispersed in a binder to form a film-like electroluminescent layer. When particles having a desired size cannot be obtained sufficiently by the method for manufacturing a light emitting material, the particles may be processed into particles by pulverization or the like in a mortar or the like. A binder is a substance for fixing a granular light emitting material in a dispersed state and maintaining the shape as an electroluminescent layer. The light emitting material is uniformly dispersed and fixed in the electroluminescent layer by the binder.

In the case of a dispersion-type inorganic EL element, the electroluminescent layer can be formed by a droplet discharge method capable of selectively forming an electroluminescent layer, a printing method (screen printing, offset printing, etc.), a coating method such as a spin coating method, A dipping method, a dispenser method, or the like can also be used. The film thickness is not particularly limited, but is preferably in the range of 10 to 1000 nm. In the electroluminescent layer including the light emitting material and the binder, the ratio of the light emitting material may be 50 wt% or more and 80 wt% or less.

24A to 24C illustrate an example of a dispersion-type inorganic EL element that can be used as a light-emitting element. A light-emitting element in FIG. 24A has a stacked structure of a first electrode layer 60, an electroluminescent layer 62, and a second electrode layer 63, and a luminescent material 61 held by a binder in the electroluminescent layer 62. Including.

As a binder that can be used in this embodiment mode, an organic material or an inorganic material can be used, and a mixed material of an organic material and an inorganic material may be used. As the organic material, a polymer having a relatively high dielectric constant such as a cyanoethyl cellulose resin, or a resin such as polyethylene, polypropylene, polystyrene resin, silicone resin, epoxy resin, or vinylidene fluoride can be used. Alternatively, a heat-resistant polymer such as aromatic polyamide, polybenzimidazole, or siloxane resin may be used. Note that a siloxane resin corresponds to a resin including a Si—O—Si bond. Siloxane has a skeleton structure formed of a bond of silicon (Si) and oxygen (O). As a substituent, an organic group containing at least hydrogen (for example, an alkyl group or an aromatic hydrocarbon) is used. A fluoro group may be used as a substituent. Alternatively, an organic group containing at least hydrogen and a fluoro group may be used as a substituent. Moreover, resin materials such as vinyl resins such as polyvinyl alcohol and polyvinyl butyral, phenol resins, novolac resins, acrylic resins, melamine resins, urethane resins, and oxazole resins (polybenzoxazole) may be used. The dielectric constant can be adjusted by appropriately mixing fine particles of high dielectric constant such as barium titanate (BaTiO ₃ ) and strontium titanate (SrTiO ₃ ) with these resins.

As the inorganic material contained in the binder, silicon oxide (SiOx), silicon nitride (SiNx), silicon containing oxygen and nitrogen, aluminum nitride (AlN), aluminum containing oxygen and nitrogen or aluminum oxide (Al ₂ O ₃ ), Titanium oxide (TiO ₂ ), BaTiO ₃ , SrTiO ₃ , lead titanate (PbTiO ₃ ), potassium niobate (KNbO ₃ ), lead niobate (PbNbO ₃ ), tantalum oxide (Ta ₂ O ₅ ), barium tantalate ( BaTa ₂ O ₆ ), lithium tantalate (LiTaO ₃ ), yttrium oxide (Y ₂ O ₃ ), zirconium oxide (ZrO ₂ ), and other materials selected from substances including inorganic materials can be used. By including an inorganic material having a high dielectric constant in the organic material (by addition or the like), the dielectric constant of the electroluminescent layer made of the light emitting material and the binder can be further controlled, and the dielectric constant can be further increased. . When a mixed layer of an inorganic material and an organic material is used for the binder and the dielectric constant is high, a larger charge can be induced in the light emitting material.

In the manufacturing process, the light-emitting material is dispersed in a solution containing a binder, but as a solvent for the solution containing the binder that can be used in this embodiment, a method of forming an electroluminescent layer by dissolving the binder material (various types) The wet process) and a solvent capable of producing a solution having a viscosity suitable for a desired film thickness may be selected as appropriate. For example, when a siloxane resin is used as a binder, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate (also referred to as PGMEA), 3-methoxy-3-methyl-1-butanol (also referred to as MMB) can be used. Etc. can be used.

The light-emitting element illustrated in FIGS. 24B and 24C has a structure in which an insulating layer is provided between the electrode layer and the electroluminescent layer in the light-emitting element in FIG. The light-emitting element illustrated in FIG. 24B includes an insulating layer 64 between the first electrode layer 60 and the electroluminescent layer 62, and the light-emitting element illustrated in FIG. 24C includes the first electrode layer 60. And an electroluminescent layer 62, and an insulating layer 64 b between the second electrode layer 63 and the electroluminescent layer 62. Thus, the insulating layer may be provided only between one of the pair of electrode layers sandwiching the electroluminescent layer, or may be provided between both. Further, the insulating layer may be a single layer or a stacked layer including a plurality of layers.

In FIG. 24B, the insulating layer 64 is provided so as to be in contact with the first electrode layer 60; however, the order of the insulating layer and the electroluminescent layer is reversed so as to be in contact with the second electrode layer 63. An insulating layer 64 may be provided on the substrate.

Insulating layers such as the insulating layer 54 in FIG. 23 and the insulating layer 64 in FIG. 24 are not particularly limited, but preferably have a high withstand voltage, a dense film quality, and a high dielectric constant. It is preferable. For example, silicon oxide (SiO ₂ ), yttrium oxide (Y ₂ O ₃ ), titanium oxide (TiO ₂ ), aluminum oxide (Al ₂ O ₃ ), hafnium oxide (HfO ₂ ), tantalum oxide (Ta ₂ O ₅ ), Barium titanate (BaTiO ₃ ), strontium titanate (SrTiO ₃ ), lead titanate (PbTiO ₃ ), silicon nitride (Si ₃ N ₄ ), zirconium oxide (ZrO ₂ ), etc., a mixed film thereof, or two or more kinds thereof A laminated film can be used. These insulating films can be formed by sputtering, vapor deposition, CVD, or the like. The insulating layer may be formed by dispersing particles of these insulating materials in a binder. The binder material may be formed using the same material and method as the binder contained in the electroluminescent layer. The film thickness is not particularly limited, but is preferably in the range of 10 to 1000 nm.

The light-emitting element described in this embodiment can emit light by applying a voltage between a pair of electrode layers sandwiching an electroluminescent layer, but can operate in either direct current drive or alternating current drive.

In the display device of the present embodiment, since the antireflection film having a plurality of convex portions is provided on the display device display screen surface, the number of times of entering the antireflection film among the external light incident on the display device is increased. The amount of light transmitted through the antireflection film increases. Therefore, the external light reflected on the viewer side is reduced, and the cause of lower visibility such as reflection can be prevented.

INDUSTRIAL APPLICABILITY The present invention can provide a display device with high visibility having a high antireflection function that can reduce reflection of external light by providing an antireflection film having a plurality of convex portions on the surface. Therefore, a display device with high image quality and high performance can be manufactured according to the present invention.

This embodiment mode can be freely combined with any of Embodiment Modes 1 to 3, 5, and 6 as appropriate.

(Embodiment 9)
In this embodiment, a structure of a backlight is described. The backlight is provided in the display device as a backlight unit having a light source, and the light source is surrounded by a reflector so that the backlight unit efficiently scatters light.

As shown in FIG. 16A, the backlight unit 352 can use a cold cathode tube 401 as a light source. In addition, a lamp reflector 332 can be provided in order to reflect light from the cold cathode tube 401 efficiently. The cold cathode tube 401 is often used for a large display device. This is due to the intensity of the luminance from the cold cathode tube. Therefore, a backlight unit having a cold cathode tube can be used for a display of a personal computer.

As shown in FIG. 16B, the backlight unit 352 can use a light emitting diode (LED) 402 as a light source. For example, light emitting diodes (W) 402 that emit white light are arranged at predetermined intervals. In addition, a lamp reflector 332 can be provided in order to efficiently reflect light from the light emitting diode (W) 402.

As shown in FIG. 16C, the backlight unit 352 can use light emitting diodes (LEDs) 403, 404, and 405 of each color RGB as light sources. By using the light emitting diodes (LEDs) 403, 404, and 405 of each color RGB, color reproducibility can be improved as compared with only the light emitting diode (W) 402 that emits white. In addition, a lamp reflector 332 can be provided in order to efficiently reflect light from the light emitting diode.

Further, as shown in FIG. 16D, when light-emitting diodes (LEDs) 403, 404, and 405 of each color RGB are used as the light source, it is not necessary to make the number and arrangement thereof the same. For example, a plurality of colors with low emission intensity (for example, green) may be arranged.

Further, a light emitting diode 402 that emits white and a light emitting diode (LED) 403, 404, and 405 of each color RGB may be used in combination.

In the case of having RGB light emitting diodes, when the field sequential mode is applied, color display can be performed by sequentially lighting the RGB light emitting diodes according to time.

When a light-emitting diode is used, it has high luminance and is suitable for a large display device. Further, since the color purity of each of the RGB colors is good, the color reproducibility is superior to that of the cold cathode tube, and the arrangement area can be reduced. Therefore, when the display is adapted to a small display device, the frame can be narrowed.

Further, it is not always necessary to arrange the light source as the backlight unit shown in FIG. For example, when a backlight having a light emitting diode is mounted on a large display device, the light emitting diode can be disposed on the back surface of the substrate. At this time, the light emitting diodes can maintain predetermined intervals, and the light emitting diodes of the respective colors can be arranged in order. The color reproducibility can be improved by the arrangement of the light emitting diodes.

A display with excellent visibility with a high antireflection function that can reduce reflection of external light by providing an antireflection film having a plurality of convex portions on the surface of a display device using such a backlight. An apparatus can be provided. Therefore, a display device with high image quality and high performance can be manufactured according to the present invention. In particular, a backlight including a light-emitting diode is suitable for a large display device, and a high-quality image can be provided even in a dark place by increasing the contrast ratio of the large display device.

This embodiment mode can be freely combined with any of Embodiment Modes 1 to 4 as appropriate.

(Embodiment 10)
FIG. 15 shows an example of an EL display module manufactured by applying the present invention. In FIG. 15, a pixel portion including pixels is formed over a substrate 2800. As the substrate 2800 and the sealing substrate 2820, flexible substrates are used.

In FIG. 15, outside the pixel portion, between the driver circuit and the pixel, the same TFT as that formed in the pixel or the gate of the TFT and one of the source or drain is connected to be the same as the diode. The protection circuit portion 2801 operated in the above is provided. As the driver circuit 2809, a driver IC formed of a single crystal semiconductor, a stick driver IC formed of a polycrystalline semiconductor film over a glass substrate, a driver circuit formed of SAS, or the like is applied.

The substrate 2800 to which the element layer is transferred is fixed to the sealing substrate 2820 through spacers 2806a and 2806b formed by a droplet discharge method. The spacer is preferably provided to keep the distance between the two substrates constant even when the substrate is thin and the area of the pixel portion is increased. A light-transmitting resin material may be filled in the gap between the substrate 2800 and the sealing substrate 2820 on the light-emitting element 2804 and the light-emitting element 2805 connected to the TFT 2802 and the TFT 2803, respectively, and may be solidified. Alternatively, anhydrous nitrogen or inert gas may be filled. An antireflection film 2827 having a convex portion is provided outside the sealing substrate 2820 on the viewing side.

FIG. 15 shows a case where the light-emitting element 2804 and the light-emitting element 2805 have a top emission type (top emission type) configuration, and emits light in the direction of the arrow shown in the drawing. Each pixel can perform multicolor display by changing the emission color of the pixels to red, green, and blue. At this time, by forming the colored layer 2807a, the colored layer 2807b, and the colored layer 2807c corresponding to each color on the sealing substrate 2820 side, the color purity of the emitted light can be increased. Alternatively, the pixel may be combined with a colored layer 2807a, a colored layer 2807b, or a colored layer 2807c as a white light emitting element.

A driver circuit 2809 which is an external circuit is connected to a scanning line or a signal line connection terminal provided at one end of the external circuit board 2811 through a wiring board 2810. In addition, a heat pipe 2813 and a heat radiating plate 2812 which are pipe-like high-efficiency heat conduction devices used for transferring heat to the outside of the device in contact with or close to the substrate 2800 are provided to enhance the heat radiation effect. It is also good.

  Although the top emission EL module is shown in FIG. 15, the configuration of the light emitting element and the arrangement of the external circuit board may be changed to have a bottom emission structure, and of course, a dual emission structure in which light is emitted from both the upper and lower surfaces. In the case of a top emission type structure, an insulating layer serving as a partition wall may be colored and used as a black matrix. The partition walls can be formed by a droplet discharge method, and may be formed by mixing a resin material such as polyimide with a pigment-based black resin, carbon black, or the like, or may be a laminate thereof.

  Moreover, you may make it cut off the reflected light of the light which injects from the outside using a phase difference plate or a polarizing plate. An insulating layer serving as a partition wall may be colored and used as a black matrix. This partition wall can be formed by a droplet discharge method, and carbon black or the like may be mixed with a resin material such as polyimide, or may be a laminate thereof. A partition may be formed by discharging different materials to the same region a plurality of times by a droplet discharge method. As the retardation plate, a λ / 4 plate or a λ / 2 plate may be used and designed so that light can be controlled. As a structure, it becomes a TFT element substrate, a light emitting element, a sealing substrate (sealing material), a retardation plate (λ / 4, λ / 2), and a polarizing plate in order, and light emitted from the light emitting element passes through them. The light is emitted from the polarizing plate side to the outside. The retardation plate and the polarizing plate may be installed on the side from which light is emitted, and may be installed on both sides as long as the display is a double-sided emission type that emits light on both sides. Further, an antireflection film may be provided outside the polarizing plate. Thereby, a more delicate and precise image can be displayed.

  In the present invention, an antireflection film having a plurality of convex portions is provided on the substrate on the viewing side. In the sealing structure on the opposite side of the viewing side and the element, a sealing material or the like is provided on the side where the pixel portion is formed. A sealing structure may be formed by attaching a resin film using an adhesive resin. Various sealing methods such as resin sealing with resin, plastic sealing with plastic, and film sealing with a film can be used. A gas barrier film for preventing the permeation of water vapor may be provided on the surface of the resin film. By adopting a film sealing structure, further reduction in thickness and weight can be achieved.

In the display device of the present embodiment, since the antireflection film having a plurality of convex portions is provided on the display device display screen surface, the number of times of entering the antireflection film among the external light incident on the display device is increased. The amount of light transmitted through the antireflection film increases. Therefore, the external light reflected on the viewer side is reduced, and the cause of lower visibility such as reflection can be prevented.

INDUSTRIAL APPLICABILITY The present invention can provide a display device with high visibility having a high antireflection function that can reduce reflection of external light by providing an antireflection film having a plurality of convex portions on the surface. Therefore, a display device with high image quality and high performance can be manufactured according to the present invention.

This embodiment mode can be combined with any of Embodiment Modes 1 to 3, 5 to 8 as appropriate.

(Embodiment 11)
This embodiment will be described with reference to FIGS. 14A and 14B. 14A and 14B illustrate an example of a display device (a liquid crystal display module) that is formed using a TFT substrate 2600 manufactured by applying the present invention.

FIG. 14A illustrates an example of a liquid crystal display module. A TFT substrate 2600 and a counter substrate 2601 are fixed to each other with a sealant 2602, and a pixel portion 2603 including a TFT and the like, a display element 2604 including a liquid crystal layer, and a coloring layer 2605 are interposed therebetween. A polarizing plate 2606 is provided to form a display area. The colored layer 2605 is necessary for color display. In the case of the RGB method, a colored layer corresponding to each color of red, green, and blue is provided corresponding to each pixel. An antireflection film 2626, a polarizing plate 2607, and a diffusion plate 2613 are disposed outside the TFT substrate 2600 and the counter substrate 2601, and a polarizing plate 2606 is disposed between the TFT substrate 2600 and the counter substrate 2601. The light source is composed of a cold cathode tube 2610 and a reflection plate 2611. The circuit board 2612 is connected to the TFT substrate 2600 by a flexible wiring board 2609, and an external circuit such as a control circuit or a power supply circuit is incorporated. Moreover, you may laminate | stack in the state which had the phase difference plate between the polarizing plate and the liquid-crystal layer.

In the display device in FIG. 14A, an example in which an antireflection film 2626 is provided outside the counter substrate 2601 and a polarizing plate 2606 and a colored layer 2605 are provided in this order is provided. The antireflection film 2626 may be provided on the surface of the polarizing plate 2606 in that case. In addition, the stacked structure of the polarizing plate 2606 and the colored layer 2605 is not limited to that in FIG. 14A, and may be set as appropriate depending on the materials and manufacturing process conditions of the polarizing plate 2606 and the colored layer 2605.

The liquid crystal display modules include TN (Twisted Nematic) mode, IPS (In-Plane-Switching) mode, FFS (Fringe Field Switching) mode, MVA (Multi-domain Vertical Alignment) mode, PVA (SMB) Axial Symmetrical Aligned Micro-cell (OCB) mode, OCB (Optical Compensated Birefringence) mode, FLC (Ferroelectric Liquid Crystal) mode, AFLC (Anti-Ferroelectric Liquid) Kill.

FIG. 14B is an example in which the OCB mode is applied to the liquid crystal display module of FIG. 14A, and is an FS-LCD (Field sequential-LCD). The FS-LCD emits red light, green light, and blue light in one frame period, and can perform color display by combining images using time division. Further, since each light emission is performed by a light emitting diode or a cold cathode tube, a color filter is unnecessary. Therefore, it is not necessary to arrange the color filters of the three primary colors and limit the display area of each color, and it is possible to display all three colors in any area. On the other hand, since the three colors emit light in one frame period, a high-speed response of the liquid crystal is required. By applying the FLC mode using the FS method and the OCB mode to the display device of the present invention, a high-performance and high-quality display device and a liquid crystal television device can be completed.

The liquid crystal layer in the OCB mode has a so-called π cell structure. The π cell structure is a structure in which the pretilt angles of liquid crystal molecules are aligned in a plane-symmetric relationship with respect to the center plane between the active matrix substrate and the counter substrate. The alignment state of the π cell structure is splay alignment when no voltage is applied between the substrates, and shifts to bend alignment when a voltage is applied. This bend orientation is white. When a voltage is further applied, the bend-aligned liquid crystal molecules are aligned perpendicularly to both substrates, and light is not transmitted. In the OCB mode, high-speed response that is about 10 times faster than the conventional TN mode can be realized.

Further, as a mode corresponding to the FS method, HV (Half V) -FLC using a ferroelectric liquid crystal (FLC) capable of high-speed operation, SS (Surface Stabilized) -FLC, or the like can be used. . A nematic liquid crystal having a relatively low viscosity is used for the OCB mode, and a smectic liquid crystal having a ferroelectric phase can be used for HV-FLC and SS-FLC.

In addition, the high-speed optical response speed of the liquid crystal display module is increased by narrowing the cell gap of the liquid crystal display module. The speed can also be increased by reducing the viscosity of the liquid crystal material. The increase in speed is more effective when the pixel pitch of the pixel region of the TN mode liquid crystal display module is 30 μm or less. Further, the speed can be further increased by the overdrive method in which the applied voltage is increased (or decreased) for a moment.

The liquid crystal display module in FIG. 14B is a transmissive liquid crystal display module, and a red light source 2910a, a green light source 2910b, and a blue light source 2910c are provided as light sources. The light source is provided with a controller 2912 for controlling on / off of the red light source 2910a, the green light source 2910b, and the blue light source 2910c. The light emission of each color is controlled by the control unit 2912, light enters the liquid crystal, an image is synthesized using time division, and color display is performed.

In the display device of the present embodiment, since the antireflection film having a plurality of convex portions is provided on the display device display screen surface, the number of times of entering the antireflection film among the external light incident on the display device is increased. The amount of light transmitted through the antireflection film increases. Therefore, the external light reflected on the viewer side is reduced, and the cause of lower visibility such as reflection can be prevented.

INDUSTRIAL APPLICABILITY The present invention can provide a display device with high visibility having a high antireflection function that can reduce reflection of external light by providing an antireflection film having a plurality of convex portions on the surface. Therefore, a display device with high image quality and high performance can be manufactured according to the present invention.

This embodiment mode can be combined with any of Embodiment Modes 1 to 4 and 9 as appropriate.

(Embodiment 12)
With the display device formed according to the present invention, a television device (also simply referred to as a television or a television receiver) can be completed. FIG. 19 is a block diagram showing a main configuration of the television device.

FIG. 17A is a top view illustrating a structure of a display panel according to the present invention. A pixel portion 2701 in which pixels 2702 are arranged in a matrix over a substrate 2700 having an insulating surface, a scanning line side input terminal 2703, a signal A line side input terminal 2704 is formed. The number of pixels may be provided in accordance with various standards. For full color display using XGA and RGB, 1024 × 768 × 3 (RGB), and for full color display using UXGA and RGB, 1600 × 1200. If it corresponds to x3 (RGB) and full spec high vision and is full color display using RGB, it may be set to 1920 x 1080 x 3 (RGB).

The pixels 2702 are arranged in a matrix by a scan line extending from the scan line side input terminal 2703 and a signal line extending from the signal line side input terminal 2704 intersecting. Each pixel of the pixel portion 2701 is provided with a switching element and a pixel electrode layer connected to the switching element. A typical example of a switching element is a TFT. By connecting the gate electrode layer side of the TFT to a scanning line and the source or drain side to a signal line, each pixel can be controlled independently by a signal input from the outside. It is said.

FIG. 17A shows the structure of a display panel in which signals input to the scan lines and signal lines are controlled by an external driver circuit. As shown in FIG. 18A, COG (Chip on The driver IC 2751 may be mounted on the substrate 2700 by a glass method. As another mounting mode, a TAB (Tape Automated Bonding) method as shown in FIG. 18B may be used. The driver IC may be formed on a single crystal semiconductor substrate or may be a circuit in which a TFT is formed on a glass substrate. In FIG. 18, the driver IC 2751 is connected to an FPC (Flexible Printed Circuit) 2750.

In the case where a TFT provided for a pixel is formed using a crystalline semiconductor, a scan line driver circuit 3702 can be formed over a substrate 3700 as shown in FIG. In FIG. 17B, the pixel portion 3701 is controlled by an external driver circuit as in FIG. 17A connected to the signal line side input terminal 3704. In the case where a TFT provided for a pixel is formed using a polycrystalline (microcrystalline) semiconductor, a single crystal semiconductor, or the like with high mobility, as illustrated in FIG. 17C, a pixel portion 4701, a scan line driver circuit 4702, and a signal The line driver circuit 4704 can be formed over the substrate 4700 integrally.

In the display panel, as shown in FIG. 17A, only the pixel portion 901 is formed in FIG. 19, and the scan line side driver circuit 903 and the signal line side driver circuit 902 are formed as shown in FIG. The TFT is formed as shown in FIG. 17B when mounted by the TAB method as shown in FIG. 18A, when mounted by the COG method as shown in FIG. In the case where the driver circuit 903 is formed over the substrate and the signal line driver circuit 902 is separately mounted as a driver IC, as shown in FIG. 17C, the pixel portion 901, the signal line driver circuit 902, and the scanning line driver circuit There is a case where 903 is integrally formed on the substrate, but any form is possible.

In FIG. 19, as other external circuit configurations, on the video signal input side, among the signals received by the tuner 904, the video signal amplification circuit 905 that amplifies the video signal and the signal output therefrom are red, green , A video signal processing circuit 906 for converting into a color signal corresponding to each color of blue, a control circuit 907 for converting the video signal into an input specification of the driver IC, and the like. The control circuit 907 outputs signals to the scanning line side and the signal line side, respectively. In the case of digital driving, a signal dividing circuit 908 may be provided on the signal line side so that an input digital signal is divided into m pieces and supplied.

Of the signals received by the tuner 904, the audio signal is sent to the audio signal amplifier circuit 909, and the output is supplied to the speaker 913 via the audio signal processing circuit 910. The control circuit 911 receives control information on the receiving station (reception frequency) and volume from the input unit 912 and sends a signal to the tuner 904 and the audio signal processing circuit 910.

As shown in FIGS. 20A and 20B, these display modules can be incorporated into a housing to complete a television device. If a liquid crystal display module is used as the display module, a liquid crystal television device can be manufactured. If an EL module is used, an EL television device, a plasma television, an electronic paper, or the like can be manufactured. In FIG. 20A, a main screen 2003 is formed using a display module, and a speaker portion 2009, operation switches, and the like are provided as accessory equipment. Thus, a television device can be completed according to the present invention.

A display panel 2002 is incorporated in a housing 2001, and general television broadcasting is received by a receiver 2005, and connected to a wired or wireless communication network via a modem 2004 (one direction (from a sender to a receiver)). ) Or bi-directional (between the sender and the receiver, or between the receivers). The television device can be operated by a switch incorporated in the housing or a separate remote control device 2006, and the remote control device 2006 also includes a display unit 2007 for displaying information to be output. good.

In addition, the television device may have a configuration in which a sub screen 2008 is formed using the second display panel in addition to the main screen 2003 to display channels, volume, and the like. In this configuration, the main screen 2003 and the sub-screen 2008 can be formed using the liquid crystal display panel of the present invention, the main screen 2003 is formed using an EL display panel with an excellent viewing angle, and the sub-screen has low power consumption. It may be formed of a liquid crystal display panel that can be displayed with In order to prioritize the reduction in power consumption, the main screen 2003 may be formed using a liquid crystal display panel, the sub screen may be formed using an EL display panel, and the sub screen may blink. When the present invention is used, a highly reliable display device can be obtained even when such a large substrate is used and a large number of TFTs and electronic components are used.

FIG. 20B illustrates a television device having a large display portion of 20 to 80 inches, for example, which includes a housing 2010, a display portion 2011, a remote control device 2012 that is an operation portion, a speaker portion 2013, and the like. The present invention is applied to manufacture of the display portion 2011. The television device in FIG. 20B is a wall-hanging type and does not require a large installation space.

Of course, the present invention is not limited to a television device, but can be applied to various uses such as a monitor for a personal computer, an information display board in a railway station or airport, an advertisement display board in a street, etc. can do.

This embodiment mode can be freely combined with any of Embodiment Modes 1 to 11 as appropriate.

(Embodiment 13)
As electronic devices according to the present invention, portable information such as a television device (also simply referred to as a television or a television receiver), a digital camera, a digital video camera, a cellular phone device (also simply referred to as a cellular phone or a cellular phone), a PDA, etc. Examples include a terminal, a portable game machine, a computer monitor, a computer, an audio playback device such as a car audio, and an image playback device including a recording medium such as a home game machine. A specific example will be described with reference to FIG.

A portable information terminal device illustrated in FIG. 21A includes a main body 9201, a display portion 9202, and the like. The display device of the present invention can be applied to the display portion 9202. As a result, a high-performance portable information terminal device that can display a high-quality image with excellent visibility can be provided.

A digital video camera shown in FIG. 21B includes a display portion 9701, a display portion 9702, and the like. The display device of the present invention can be applied to the display portion 9701. As a result, a high-performance digital video camera that can display high-quality images with excellent visibility can be provided.

A cellular phone shown in FIG. 21C includes a main body 9101, a display portion 9102, and the like. The display device of the present invention can be applied to the display portion 9102. As a result, a high-performance mobile phone that can display high-quality images with excellent visibility can be provided.

A portable television device illustrated in FIG. 21D includes a main body 9301, a display portion 9302, and the like. The display device of the present invention can be applied to the display portion 9302. As a result, a high-performance portable television device that can display a high-quality image with excellent visibility can be provided. In addition, the present invention can be applied to a wide variety of television devices, from a small one mounted on a portable terminal such as a cellular phone to a medium-sized one that can be carried and a large one (for example, 40 inches or more). The display device can be applied.

A portable computer shown in FIG. 21E includes a main body 9401, a display portion 9402, and the like. The display device of the present invention can be applied to the display portion 9402. As a result, a high-performance portable computer that can display a high-quality image with excellent visibility can be provided.

As described above, the display device of the present invention can provide a high-performance electronic device that can display a high-quality image with excellent visibility.

This embodiment mode can be freely combined with any of Embodiment Modes 1 to 12 as appropriate.

In this embodiment, the result of optical calculation using the antireflection film used in the present invention will be described. For comparison, optical calculation was also performed for an antireflection film having a laminated structure. This embodiment will be described with reference to Tables 1 and 2 and FIGS.

The calculation in the present embodiment uses an optical calculation simulator for the optical device FullWAVE (manufactured by Rsoft Co., Ltd.). The reflectance was calculated by optical calculation in two dimensions.

As a comparative example, calculation was performed regarding reflection of external light of an antireflection film having a multilayer structure composed of a stack of a low refractive index layer and a high refractive index layer. As shown in FIG. 26, the comparative example has a high refractive index layer 11a (n = 1.9) and a low refractive index layer 11b (n = 1.34) on a glass substrate 10 (n = 1.52, reflectance 4%). The surface of the low refractive index layer 11b is exposed to air 12 (n = 1.0). Table 1 shows the structure, refractive index, and thickness of the comparative example.

The high refractive index layer 11a is a thin film (Q: also indicated as λ / 4) set so that the optical path length (actual distance × refractive index) is a quarter of the wavelength λ550 nm with high visibility. Since the refractive index layer 11b is a thin film (also shown as H: λ / 2) that is set so that the optical path length (actual distance × refractive index) is ½ of the wavelength 550 nm with high visibility, the antireflection film Reference numeral 11 denotes a so-called QH type antireflection film. Light corresponding to outside light was irradiated vertically from the air side from above the glass substrate 10 and the antireflection film 11, and reflected light reflected from the glass substrate 10 and antireflection film 11 to the air side was detected by the monitor 14. The light emitted from the light source 13 passes through the air layer and enters the low refractive index layer 11b, the high refractive index layer 11a, and the glass substrate 10.

FIG. 27 shows the relationship between the wavelength and the reflectance in the comparative example. As shown in FIG. 27, the reflectance is not constant in the measurement region wavelength of 380 nm to 780 nm, which is the visible light region, and wavelength dependence is observed. The reflectance is 1% or less near the wavelength of about 450 nm to about 750 nm, but the reflectance increases in the short wavelength and long wavelength regions of 450 nm or less and 750 or more. This increase in reflectance was particularly noticeable for short wavelengths of 450 nm or less and ultraviolet light. Thus, it is difficult for the laminated structure as in the comparative example to show a uniform low reflectance in the measurement region wavelength of 380 nm to 780 nm, which is the visible light region, and the reflectance is about 550 nm. It can be confirmed that it is difficult to reduce only about 1%.

Calculation was performed regarding the reflection of the antireflection film having a convex portion on the surface using the present invention with respect to external light. In this embodiment, a plurality of conical convex portions adjacent to each other are used as the samples A1 to A8, and the cross section of the convex portion in a plane perpendicular to the bottom surface is an isosceles triangle as shown in FIG. In FIG. 28, a convex portion 21 is provided on the substrate 20. As shown in the cross section, the angle θ, which is an inclination angle, is determined depending on the ratio between the height H of the cone and the diameter L of the bottom surface. Cone height H: bottom diameter L is 29: 1, 10: 1, 9.5: 1, 5.7: 1, 4.1: 1, 2.8: 1, 2.4: 1, 1 .9: 1, the angle θ is 89, 87.2, 87, 85, 83, 80, 78, 75 (deg.), And the light corresponding to the external light is incident on the samples A1 to A8. The reflectance of light reflected from the antireflection film having the above was calculated. Table 2 shows the angles θ, height H: diameter (base) L, height H, and diameter (base) L in the cross sections of the samples A1 to A8.

Further, the convex portion is made of silicon nitride containing oxygen, and the refractive index with respect to the wavelength of light is set (for example, refractive index 1.48 (wavelength 380 nm), 1.47 (wavelength 550 nm), 1.46 (wavelength 780 nm)). A substrate provided with an antireflection film having a glass substrate (refractive index of 1.52) was used.

FIG. 29 shows the relationship between the wavelength of external light and the reflectance of samples A1 to A8. As shown in FIG. 29, in samples A1 to A5, the reflectance was about 0.2% or less in the measured visible light wavelength region (380 nm to 700 nm), but in samples A6 to A8, the reflectance was in the visible light wavelength region. The reflectivity was about 0.2% or more, and a large value of about 0.4% to about 0.8% depending on the wavelength. FIG. 30 is a graph showing the result of FIG. 29 in the relationship between the angle of the hypotenuse of the convex portion and the average reflectance at the measurement wavelength. Sample A1 has an angle of 89 degrees, Sample A2 has an angle of 87.2 degrees, Sample A3 has an angle of 87 degrees, Sample A4 has an angle of 85 degrees, Sample A5 has an angle of 83 degrees, Sample A6 has an angle of 80 degrees, and Sample A7 has an angle of 78 degrees Sample A8 corresponds to an angle of 75 degrees. The average reflectivity is 0.1% or less at an angle of 84 degrees or more and less than 90 degrees, whereas the average reflectivity suddenly increases to around 0.25% at 82 degrees and 80 degrees. From this result, when the angle of the hypotenuse of the convex portion is 84 degrees or more and less than 90 degrees, reflection of external light can be reduced to an average reflectance of 0.1% or less. Therefore, it can be confirmed that the antireflection film of the present invention exhibits a high antireflection effect.

In this example, the reflection with respect to external light of the antireflection film having a convex portion on the surface using the present invention was calculated. This embodiment will be described with reference to Table 3, FIG. 31 and FIG.

Calculation was performed regarding the reflection of the antireflection film having a convex portion on the surface using the present invention with respect to external light. In this embodiment, a conical convex portion is used as the sample B as in the first embodiment, and the convex portion has an isosceles triangle as shown in FIG. As shown in the cross section, the angle θ is determined depending on the ratio between the height H of the cone and the diameter L of the bottom surface. Cone height H: The bottom diameter L is 10: 1, and the cone height H is 1.0 μm so that the angle 87.2 degrees (deg.) Showing the low reflectance in FIG. The diameter L of the bottom surface was changed to 1.5 μm, 2.0 μm, 2.25 μm, 2.5 μm, and 3.0 μm, and accordingly the size of the diameter L of the bottom surface was 0.1 μm, 0.15 μm, 0.20 μm, 0.225 μm,. Samples B1 to B6 are changed to 25 μm and 0.30 μm. Light corresponding to external light was incident on the samples B1 to B6, and the reflectance of light reflected from the antireflection film having a convex portion was calculated. Table 3 shows the angles θ, height H: diameter (base) L, height H, and diameter (base) L in the cross sections of the samples B1 to B6.

Further, the convex portion is made of silicon nitride containing oxygen, and the refractive index with respect to the wavelength of light is set (for example, refractive index 1.48 (wavelength 380 nm), 1.47 (wavelength 550 nm), 1.46 (wavelength 780 nm)). A substrate provided with an antireflection film having a glass substrate (refractive index of 1.52) was used.

FIG. 31 shows the relationship between the wavelength of external light and the reflectance of samples B1 to B6. As shown in FIG. 31, in samples B1 to B6, the reflectance was about 0.08% or less in the measured visible light wavelength region (380 nm to 700 nm). FIG. 32 is a graph showing the result of FIG. 31 in the relationship between the height of the hypotenuse of the convex portion and the average reflectance at the measurement wavelength. Sample B1 corresponds to a height of 1 μm, sample B2 corresponds to a height of 1.5 μm, sample B3 corresponds to a height of 2.0 μm, sample B4 corresponds to a height of 2.25 μm, sample B5 corresponds to 2.5 μm, and sample B6 corresponds to 3 μm. Yes. At a height of 1 μm to 3 μm, the average reflectance is 0.04% or less. From this result, it is possible to reduce the reflection of external light to a reflectance of 0.04% or less in the range of 1 μm to 3 μm in height when the size of the convex portion is 87 ° and the angle of the hypotenuse is 2 °, and a high antireflection effect Can be confirmed. Moreover, the translucency with respect to the light of a visible region does not fall that it is a convex part in height of 1 micrometer-3 micrometers.

In this example, the reflection with respect to external light of the antireflection film having a convex portion on the surface using the present invention was calculated. This embodiment will be described with reference to Table 4 and FIGS.

Calculation was performed regarding the reflection of the antireflection film having a convex portion on the surface using the present invention with respect to external light. In this example, as the samples C1 to C7, a plurality of conical convex portions having upper and lower surfaces are used as adjacent surfaces, and the convex portion has a trapezoidal cross section in a plane perpendicular to the bottom surface as shown in FIG. In FIG. 33, a convex portion 31 is provided on the substrate 30. As shown in the cross section, the height of the trapezoid is 1 μm, and the angle θ is determined depending on the ratio of the diameter of the upper bottom surface (referred to as the upper base a) and the diameter of the lower base surface (referred to as the lower base b). Change the upper base a / lower base b to 0, 0.05, 0.075, 0.1, 0.125, 0.15, 0.2, and respond to external light to samples C1 to C7 at each angle θ The reflectance of light reflected by an antireflection film having a convex portion was calculated. Note that the sample C1 having an upper base a / lower base b of 0 indicates that there is no upper base and a conical shape. Table 4 shows the upper base a / lower base b in the cross section of the samples C1 to C7.

Further, the convex portion is made of silicon nitride containing oxygen, and the refractive index with respect to the wavelength of light is set (for example, refractive index 1.48 (wavelength 380 nm), 1.47 (wavelength 550 nm), 1.46 (wavelength 780 nm)). A substrate provided with an antireflection film having a glass substrate (refractive index of 1.52) was used.

FIG. 34 shows the relationship between the wavelength of external light and the reflectance of samples C1 to C7. As shown in FIG. 34, in the samples C1 to C7, the reflectance was about 0.35% or less in the measured visible light wavelength region (380 nm to 780 nm). FIG. 35 is a graph showing the result of FIG. 34 in the relationship between the upper base a / the lower base b and the average reflectance at the measurement wavelength indicating the ratio of the upper base a and the lower base b. Sample C1 is 0 in the upper base a / lower base b, sample C1 is 0, sample C2 is 0.05, sample C3 is 0.075, sample C4 is 0.1, sample C5 is 0.125, and sample C6 is 0.15 Sample C7 corresponds to 0.2 respectively. The average reflectance gradually increases as the ratio increases, but the average reflectance is about 0.3% or less at a ratio of 0 to 0.2. This is because the angle θ of the hypotenuse increases as the value of the upper base a / lower base b increases, but the area of the upper base also increases, so that reflection of external light on the upper base is considered to be large. . From this result, in the convex portion having the upper bottom surface and the lower bottom surface, the reflection of outside light is less than about 0.35% and the average reflectance is about 0. It can be reduced to 3% or less, and it can be confirmed that a high antireflection effect is exhibited.

It is a conceptual diagram of this invention. It is a conceptual diagram of this invention. It is a conceptual diagram of this invention. It is sectional drawing which showed the display apparatus of this invention. It is the top view and sectional drawing which showed the display apparatus of this invention. It is sectional drawing which showed the display apparatus of this invention. It is sectional drawing which showed the display apparatus of this invention. It is the top view and sectional drawing which showed the display apparatus of this invention. It is the top view and sectional drawing which showed the display apparatus of this invention. It is sectional drawing which showed the display apparatus of this invention. It is sectional drawing which showed the display apparatus of this invention. It is sectional drawing which showed the display apparatus of this invention. It is sectional drawing which showed the display apparatus of this invention. It is sectional drawing which showed the display module of this invention. It is sectional drawing which showed the display module of this invention. It is a backlight that can be used as a display device of the present invention. It is the top view which showed the display apparatus of this invention. It is the top view which showed the display apparatus of this invention. It is a block diagram which shows the main structures of the electronic device with which this invention is applied. It is the figure which showed the electronic device of this invention. It is the figure which showed the electronic device of this invention. It is sectional drawing which showed the structure of the light emitting element which can be applied to this invention. It is sectional drawing which showed the structure of the light emitting element which can be applied to this invention. It is sectional drawing which showed the structure of the light emitting element which can be applied to this invention. It is a conceptual diagram of this invention. It is a figure which shows the experimental model of a comparative example. It is a figure which shows the experimental data of a comparative example. FIG. 3 is a diagram showing an experimental model of Example 1. 4 is a diagram showing experimental data of Example 1. FIG. 4 is a diagram showing experimental data of Example 1. FIG. 6 is a diagram showing experimental data of Example 2. FIG. 6 is a diagram showing experimental data of Example 2. FIG. 6 is a diagram illustrating an experimental model of Example 3. FIG. 6 is a diagram showing experimental data of Example 3. FIG. 6 is a diagram showing experimental data of Example 3. FIG. It is the top view and sectional drawing which showed the display apparatus of this invention.

Claims (13)

An antireflection film having a plurality of convex portions is provided on the display screen;
The display device characterized in that an angle between the bottom surface of the convex portion and the slope is not less than 84 degrees and less than 90 degrees. An antireflection having a pair of substrates, a display element provided between the pair of substrates, and at least one of the pair of substrates is a light-transmitting substrate, and has a plurality of convex portions outside the light-transmitting substrate. And having a membrane
The display device characterized in that an angle between the bottom surface of the convex portion and the slope is not less than 84 degrees and less than 90 degrees. A pair of translucent substrates; a display element provided between the pair of translucent substrates; and an antireflection film having a plurality of convex portions on the outer sides of the pair of translucent substrates. ,
The display device characterized in that an angle between the bottom surface of the convex portion and the slope is not less than 84 degrees and less than 90 degrees. 4. The display device according to claim 2, further comprising a polarizing plate between the light-transmitting substrate and the antireflection film. The display device according to claim 1, wherein the convex portion has a conical shape. 5. The display device according to claim 1, wherein the convex portion has a flat or rounded tip. 5. The display device according to claim 1, wherein the convex portion has a shape in which a cone is stacked on a cylinder. 8. The display device according to claim 1, wherein a ratio of a height of the convex portion to a diameter of the bottom surface is 5 or more and 29 or less: 1. 9. The display device according to claim 1, wherein the plurality of convex portions are adjacent to each other in contact with each other. 10. The display device according to claim 1, wherein a refractive index of the plurality of convex portions continuously changes as the substrate approaches the substrate. 11. The display device according to claim 2, wherein the display element is a liquid crystal display element. The display device according to claim 2, wherein the display element is a light emitting element. 13. The display device according to claim 1, wherein the plurality of convex portions have a height of 1 μm to 3 μm and a bottom surface diameter of 0.1 μm to 0.3 μm.

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