JP2007256939A - Display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display device with a high contrast ratio, and to manufacture such a high-performance display device at low cost. <P>SOLUTION: In a display device having a display element interposed between a pair of light-transmitting substrates, a stack of polarizer-including layers in a parallel nicol state is provided outside each of the light-transmitting substrates. Here, transmission axes of polarizers that are stacked in the stack on one side of the display element and transmission axes of polarizers that are stacked in the stack on another side of the display element are arranged to be displaced from a cross nicol state. Also, a retardation film may be provided between the polarizers that are stacked and the substrate. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a structure of a display device using a liquid crystal element.

  Recently, a display device that is very thin and light in weight compared to a conventional cathode ray tube, a so-called flat panel display, has been developed. Flat panel displays are competing with liquid crystal display devices with liquid crystal elements as display elements, light emitting devices with self-luminous elements, FED (field emission display) using electron beams, etc. Therefore, low power consumption and high contrast ratio are demanded.

  In the liquid crystal display device, a polarizing plate is generally provided on each of a pair of substrates sandwiching a liquid crystal element, and the contrast ratio is maintained. By making the black display darker, the contrast ratio can be increased, and a high display quality can be provided when an image is viewed in a dark room like a home theater.

For example, in order to improve the display non-uniformity and contrast ratio caused by insufficient polarization degree and non-uniform polarization degree distribution of the polarizing plate, the first polarizing plate, the viewing side and the outside of the substrate on the viewing side of the liquid crystal cell When a second polarizing plate is provided on the outside of the opposite substrate, the light from the auxiliary light source provided on the opposite substrate side to the viewing side is polarized through the second polarizing plate and passed through the liquid crystal cell. In order to increase the degree, a configuration in which a third polarizing plate is provided has been proposed (see Patent Document 1).
International Publication No. 00/34821

Although it is as above-mentioned, the request | requirement which raises a contrast ratio does not stop, and the further contrast-ratio improvement is calculated | required and researched in a liquid crystal display device. In addition, there is a problem that a polarizing plate having a high degree of polarization is expensive.
In view of the above, an object of the present invention is to provide a display device having a high contrast ratio by a simple method. Another object is to produce such a high-performance display device at low cost.

  In a display device having a display element between a pair of light-transmitting substrates, a layer including a plurality of polarizers stacked in parallel Nicol is provided on the outside thereof, and a layer including a plurality of polarizers sandwiching the display element The transmission axis of the other polarizer and the transmission axis of the polarizer of the layer including the other plurality of polarizers are arranged in crossed Nicols having a deviation. In that case, a retardation film is preferably provided between the layer including a plurality of polarizers and the light-transmitting substrate.

  In the present invention, a pair of layers including a plurality of polarizers respectively disposed outside the pair of light-transmitting substrates so that the black display is darkest (that is, the backlight has a low black transmittance). Each of the polarizers is arranged in crossed Nicols having a deviation, thereby obtaining a high contrast ratio.

  In the present invention, as described above, first, it is necessary to form a polarizer layer by laminating a plurality of polarizers in parallel Nicols on the outer sides of both light-transmitting substrates of the display device. In the present invention, it is necessary to dispose the transmission axis of the layer formed on one light-transmitting substrate and the transmission axis of the polarizer of the layer formed on the other light-transmitting substrate in crossed Nicols having a deviation. The greatest feature of the present invention is that it is arranged in the latter crossed Nicols.

In this way, the polarizer has a transmission axis. When the polarizers are stacked, the case where the transmission axes of the polarizers are parallel is called parallel Nicol, and the transmission axes of the polarizers are orthogonal. Is called Cross Nicole.
Therefore, the greatest feature of the present invention, that the polarizer is arranged in a crossed Nicol having a deviation means that the polarizer is arranged in the extinction position where the black display becomes the darkest extinction state.
Note that, due to the characteristics of the polarizer, there is an absorption axis in a direction orthogonal to the transmission axis. Therefore, the case where the absorption axes are parallel to each other can also be referred to as parallel Nicol, and the case where the absorption axes are orthogonal to each other can also be referred to as crossed Nicol.

  Further, the polarizer has a specific extinction coefficient with respect to the wavelength of light. This is because the wavelength dependence of the absorption characteristics of the polarizer is not constant, and the absorption characteristics in a specific wavelength region are lower than those in other wavelength regions, i.e., it is difficult to absorb only that wavelength region. It depends on. In the present invention, the extinction coefficient of the absorption axis of the laminated polarizer is the same.

  The display device of the present invention has the features as described above, but there are many forms, and one form thereof includes a first light-transmitting substrate and a second light-transmitting substrate that are arranged to face each other, and A first element including a display element sandwiched between the first light-transmissive substrate and the second light-transmissive substrate; and a plurality of polarizers stacked outside the first light-transmissive substrate. And a second layer including a plurality of polarizers stacked on the outside of the second light-transmitting substrate, and the first layer and the second layer are respectively stacked. The transmission axes of each other are arranged in parallel Nicols, and the first layer polarizer and the second layer polarizer are arranged in crossed Nicols where the transmission axes of each other are misaligned.

  Another embodiment of the display device of the present invention includes a first light-transmitting substrate and a second light-transmitting substrate which are disposed to face each other, the first light-transmitting substrate, and the second light-transmitting substrate. A display element sandwiched between substrates, a first layer including a plurality of polarizers stacked on the outside of the first light-transmitting substrate, and a layer stacked on the outside of the second light-transmitting substrate. A second layer including a plurality of polarizers, a first retardation film between the first light-transmitting substrate and the first layer, the second light-transmitting substrate, and the second A second retardation film between the first and second layers, and the first layer and the second layer are arranged so that the transmission axes of the polarizers to be stacked are parallel Nicols, The polarizer of the first layer and the polarizer of the second layer are arranged in crossed Nicols where the transmission axes of the first layer and the second layer are shifted.

  Still another embodiment of the display device according to the present invention includes a first light-transmitting substrate and a second light-transmitting substrate that are disposed to face each other, the first light-transmitting substrate, and the second light-transmitting substrate. A display element sandwiched between light-transmitting substrates, a first layer including a plurality of polarizers stacked outside the first light-transmitting substrate, and a layer stacked outside the second light-transmitting substrate A second layer including a plurality of polarizers, wherein the first layer includes a first A polarizer, a first B polarizer, and a first C polarization from the first translucent substrate side. The first layer and the second layer are arranged so that the transmission axes of the laminated polarizers are parallel Nicols, and the first layer of the polarizer and the second layer The polarizer of the second layer is arranged in crossed Nicols where the transmission axes of the second layer are shifted.

  Still another embodiment of the display device according to the present invention includes a first light-transmitting substrate and a second light-transmitting substrate that are disposed to face each other, the first light-transmitting substrate, and the second light-transmitting substrate. A display element sandwiched between light-transmitting substrates, a first layer including a plurality of polarizers stacked outside the first light-transmitting substrate, and a layer stacked outside the second light-transmitting substrate A second layer including a plurality of polarizers, a first retardation film between the first light-transmitting substrate and the first layer, the second light-transmitting substrate, and the first light-transmitting substrate. A second retardation film between the two layers, and the first layer includes a first A polarizer, a first B polarizer, and a first C polarization from the first light transmitting substrate side. The first layer and the second layer are arranged so that the transmission axes of the laminated polarizers are parallel Nicols, and the first layer of the polarizer and the second layer are laminated in the order of the polarizer. Polarizer of the second layer are arranged in a cross nicol state with a deviation transmission axis of each other.

  In the display device of the present invention, light is passed through a display element from a layer including a plurality of polarizers laminated on the side opposite to the viewing side using a light source serving as a backlight, and a plurality of polarizers laminated on the viewing side are provided. In the case of taking out from the layer including the polarizer, each polarizer in the layer including a plurality of polarizers stacked on the opposite side (backlight side) to each other has a transmission axis of parallel Nicols. This is preferable because the light transmittance is increased.

In the display device of the present invention, the polarizer is preferably arranged between the pair of protective layers. In that case, the entire layer including the stacked polarizers is interposed between the pair of protective layers. The structure provided in this may be sufficient, and the structure provided between a pair of protective layers for every polarizer may be sufficient. Further, the layer including the stacked polarizers may have a structure in which an antireflection film, an antiglare film, or the like is provided on the viewing side.

In the present invention, a transmission axis of a polarizer of a layer including a plurality of polarizers disposed outside one translucent substrate and a layer including a plurality of polarizers disposed outside the other translucent substrate The contrast ratio of the display device can be increased by a simple structure in which the transmission axis of the polarizer is arranged in crossed Nicols having a deviation. In addition, such a high-performance display device can be manufactured at low cost.
It should be noted that being arranged in a crossed Nicol having a deviation means the same as described above, but the angle is preferably −3 ° to + 3 °, and preferably −0.5 ° to + 0.5 °. By adopting this angle, it is possible to increase the contrast ratio of the display device in particular.

  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 should not be construed as being limited to the description of the embodiment modes. 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 mode, a concept of a display device using a pair of layers including stacked polarizers according to the present invention will be described.
In FIG. 1A, a pair of layers including polarizers stacked in parallel Nicols is included, and a transmission axis of polarizers of each layer, that is, a plurality of polarizers stacked with a display element interposed therebetween. FIG. 1 is a cross-sectional view of a display device having a configuration in which transmission axes of polarizers of the other layer and a polarizer of the other layer including a plurality of stacked polarizers are arranged in crossed Nicols having a shift. B) shows a perspective view of the display device. In this embodiment, a liquid crystal display device including a liquid crystal element as a display element is described as an example.

  In this embodiment, a layer including a plurality of polarizers stacked in parallel Nicols is provided on the outside of the pair of substrates, that is, the side not in contact with the liquid crystal element. Specifically, as shown in FIG. 1A, on the first substrate 101 side, the transmission axis of the layer 103 including the first A polarizer (hereinafter, the polarizer of the layer including the polarizer) As described above, the transmission axis may be abbreviated as “transmission axis of the layer including the polarizer”), and the transmission axis of the layer 104 including the first-B polarizer is provided in parallel Nicol.

Further, on the second substrate 102 side, the transmission axes of the layer 105 including the second A polarizer and the layer 106 including the second B polarizer are similarly provided in parallel Nicols.
Further, in this embodiment, a layer including a pair of a plurality of polarizers arranged with the layer 100 having a liquid crystal element in between is a polarizer in which one layer is stacked and a polarizer in which the other layer is stacked. The transmission axis is characterized by being arranged in a crossed Nicol having a deviation.

Specifically, as shown in FIG. 1B, the transmission axis (A) of the layer 103 including the 1A polarizer and the transmission axis (B) of the layer 104 including the 1B polarizer are parallel to each other. The layers are stacked so as to be in a state, that is, parallel Nicols. Similarly, the transmission axis (C) of the layer 105 including the second-A polarizer and the transmission axis (D) of the layer 106 including the second-B polarizer are stacked so as to be parallel Nicols.
Further, the transmission axis of the layer 103 including the 1A polarizer and the layer 104 including the 1B polarizer, and the transmission axis of the layer 105 including the 2A polarizer and the layer 106 including the 2B polarizer are as follows. It is arranged in crossed Nicols with a gap.

In this embodiment, the extinction coefficient of the absorption axis of the layer 103 including the first A polarizer and the layer 104 including the 1B polarizer is the same, and the layer 105 including the second A polarizer and The extinction coefficient of the absorption axis of the layer 106 including the second-B polarizer is the same.
Although not shown in FIG. 1, the irradiation means such as a backlight is disposed below the layer 106 including the second-B polarizer.

  In this embodiment mode, a pair of layers including a plurality of stacked polarizers is transmitted through each polarizer so that the black display is darkest (that is, the black transmittance of the backlight is low). The axis is arranged in a crossed Nicol with a deviation, thereby obtaining a high contrast ratio.

  The substrate is an insulating substrate having a light-transmitting property (hereinafter also referred to as a light-transmitting substrate). In particular, it has translucency in the wavelength region of visible light. For example, a glass substrate such as barium borosilicate glass or alumino borosilicate glass, a quartz substrate, or the like can be used. In addition, a substrate made of plastics typified by polyethylene-terephthalate (PET), polyethylene naphthalate (PEN), polyethersulfone (PES), polycarbonate (PC), or flexible synthetic resin such as acrylic is applied. can do. A film (made of polypropylene, polyester, vinyl, polyvinyl fluoride, vinyl chloride, etc.), an inorganic vapor deposition film, or the like can also be used.

  FIG. 5 shows the transmission axis (A) of the layer 103 including the first A polarizer, the transmission axis (B) of the layer 104 including the first B polarizer, and the transmission of the layer 105 including the second A polarizer. The figure which looked at the angle | corner which the axis | shaft (C) and the transmission axis | shaft (D) of the layer 106 containing a 2B polarizer look from the upper surface is shown. The transmission axis (A) of the layer 103 including the 1A polarizer and the transmission axis (B) of the layer 104 including the 1B polarizer, which are stacked so as to be parallel Nicols, are similarly parallel Nicol. The transmission axis (C) of the layer 105 including the second-A polarizer and the transmission axis (D) of the layer 106 including the second-B polarizer are arranged in crossed Nicols having a deviation angle θ.

  In FIG. 1, the number of polarizers in the layer including the polarizer is two, but the present invention is not limited to this and may have a multilayer structure. FIG. 3 shows an example in which a layer 121 containing a 1C polarizer is further stacked on the layer 103 containing a 1A polarizer and the layer 104 containing a 1B polarizer. In FIG. 3, the polarizer of the layer 121 including the 1C polarizer has a transmission axis (G), and the transmission axis (G) is the layer 103 including the 1A polarizer and the 1B polarizer. Is parallel to the transmission axis (B) of the layer 104 containing.

  That is, as shown in FIG. 6, the layer 121 including the 1C polarizer is parallel to the layer 103 including the 1A polarizer and the layer 104 including the 1B polarizer so that their transmission axes are parallel Nicols. Is laminated. Therefore, the layer 121 including the first C polarizer is also laminated in crossed Nicols with a “shift angle θ” from the transmission axis of the layer 105 including the second AC polarizer and the layer 106 including the second B polarizer. The

In addition, when a pair of stacked layers including a plurality of polarizers is used as in this embodiment mode, the present invention is also applied to a display device that can extract light from both sides of a substrate using a front light or the like. can do.
Thus, in a pair of layers each including a plurality of polarizers laminated in parallel Nicols, the transmission axes of the polarizers laminated in each layer are arranged in crossed Nicols with a gap across the display element. Thus, light leakage in the transmission axis direction can be reduced, and as a result, the contrast ratio of the display device can be increased.

(Embodiment 2)
In this embodiment mode, unlike in Embodiment Mode 1, a concept of a display device in which a retardation film is provided in addition to a pair of layers including a plurality of stacked polarizers will be described.
FIG. 2A shows a pair of layers including polarizers stacked in parallel Nicols, and transmission of a polarizer stacked in one layer and a polarizer stacked in the other layer with the display element interposed therebetween. A shaft is a cross-sectional view of a display device having a configuration arranged in a crossed Nicol with a shift, and FIG. 2B is a perspective view of the display device.

  In this embodiment, a liquid crystal display device including a liquid crystal element as a display element is described as an example. As shown in FIG. 2A, on the first substrate 101 side, the transmission axes of the layer 103 including the 1A polarizer and the layer 104 including the 1B polarizer are provided in parallel Nicols. . Further, on the second substrate 102 side, the transmission axes of the layer 105 including the 2A polarizer and the layer 106 including the 2B polarizer are provided in parallel Nicols.

  In this embodiment mode, the transmission axis of the polarizer in which one layer is stacked and the polarizer in which the other layer is stacked with the display element interposed therebetween is arranged in a crossed Nicol manner with a deviation. . In the present embodiment, the extinction coefficient of the absorption axis of the layer 103 including the 1A polarizer and the layer 104 including the 1B polarizer are the same, and the layer 105 including the 2A polarizer and the layer 2B include The extinction coefficient of the absorption axis of the layer 106 including the polarizer is the same.

  As shown in FIG. 2B, the layer 103 including the 1A polarizer and the layer 104 including the 1B polarizer are stacked so that their transmission axes are parallel Nicols. Further, a retardation film 113 is provided between the layer including the stacked polarizers and the first substrate 101. As shown in FIG. 2B, a layer 105 including a 2A polarizer and a layer 106 including a 2B polarizer are provided on the second substrate 102 side. The layer 105 including the polarizer and the layer 106 including the second-B polarizer are stacked so that their transmission axes are parallel Nicols. Further, a retardation film 114 is provided between the stacked layer including the polarizer and the second substrate 102.

The transmission axes of the layer 103 including the 1A polarizer and the layer 104 including the 1B polarizer, and the transmission axes of the layer 105 including the 2A polarizer and the layer 106 including the 2B polarizer are as follows. It is arranged in crossed Nicols with a gap.
Although not shown in FIG. 2, the irradiation means such as a backlight is arranged below the layer 106 including the 2B polarizer.

  Examples of the retardation film include a film in which liquid crystals are hybrid-aligned, a film in which liquid crystals are twisted and aligned, a uniaxial retardation film, or a biaxial retardation film. Such a retardation film can achieve a wide viewing angle of the display device. A film with hybrid alignment of liquid crystal is a triacetyl cellulose (TAC) film as a support, and a discotic liquid crystal having negative uniaxiality or a nematic liquid crystal having positive uniaxiality is hybrid aligned to provide optical anisotropy. Is a composite film provided with

  The uniaxial retardation film is formed by stretching a resin in one direction. The biaxial retardation film is formed by uniaxially stretching the resin in the transverse direction and then weakly uniaxially stretching in the longitudinal direction. The resin used here is cycloolefin polymer (COE), polycarbonate (PC), polymethyl methacrylate (PMMA), polystyrene (PS), polyethersulfone (PES), polyphenylene sulfide (PPS), polyethylene terephthalate (PET). , Polyethylene naphthalate (PEN), polypropylene (PP), polyphenylene oxide (PPO), polyarylate (PAR), polyimide (PI), polytetrafluoroethylene (PTFE) and the like.

These retardation films can be attached to a light-transmitting substrate in a state of being attached to a layer containing a polarizer.
The viewing angle characteristics of the display element can be improved by combining the retardation film and the laminated polarizer. In addition, a plurality of retardation films may be used. When a quarter-wave plate is used as the retardation film, it can function as a circularly polarizing plate. When a pair of circularly polarizing plates is used, reflection of light from the outside can be reduced, and the contrast ratio is further improved. Note that due to the characteristics of the retardation film, there is a fast axis in the direction orthogonal to the slow axis. Therefore, the arrangement can be determined based on the fast axis instead of the slow axis.

  In FIG. 2, the polarizer including the polarizer has two layers. However, the present invention is not limited to this and may have a multilayer structure. The layer 103 including the 1A polarizer and the layer 104 including the 1B polarizer may be stacked with the layer 121 including the 1C polarizer so as to be in parallel Nicol. FIG. 4 shows an example in which a layer 121 including a first C polarizer is further stacked on the layer 103 including a 1A polarizer and the layer 104 including a 1B polarizer.

In FIG. 4, the polarizer of the layer 121 including the first C polarizer has a transmission axis (G), and the transmission axis (G) is the transmission axis (A) of the layer 103 including the first A polarizer. And parallel to the transmission axis (B) of the layer 104 including the 1B polarizer.
Accordingly, the layer 121 including the first C polarizer is also laminated in a crossed Nicol state having a deviation angle θ from the transmission axis of the layer 105 including the second A polarizer and the layer 106 including the second B polarizer.

In addition, the pair of layers including stacked polarizers as in this embodiment mode can be applied to a display device that can extract light from both sides of a substrate using a front light or the like.
In the configuration including the pair of layers including the polarizers and the retardation film thus laminated, the transmission axes of the pair of polarizers of the layer including the polarizers are arranged in crossed Nicols having a shift. As a result, light leakage in the direction of the transmission axis can be reduced, and thus the contrast ratio of the display device can be increased.

(Embodiment 3)
In this embodiment mode, a structure of a stacked polarizer that can be used in the present invention will be described with reference to FIGS.
In the present invention, the layer containing a polarizer only needs to include a polarizer having at least a specific transmission axis, and may be a single polarizer layer, or a protective layer is provided so as to sandwich the polarizer. It may be a structure. FIG. 13 shows an example of a laminated structure of layers including a polarizer in the present invention.
In FIG. 13A, a protective layer 50a, a first A polarizer 51, a layer including a polarizer composed of a protective layer 50b, and a protective layer 50c, a first B polarizer 52, and a polarizer composed of a protective layer 50d are included. The layers are stacked, and the figure shows the layer including the stacked polarizers.

  Thus, in the specification of the present application, the plurality of stacked polarizers include those in which the polarizers are not directly in contact with each other but stacked through a protective layer, and the stacked polarizers. May be abbreviated. Then, a layer including a plurality of stacked polarizers or a layer including a stacked polarizer is a layer including a polarizer composed of the protective layer 50a, the first A polarizer 51, and the protective layer 50b. It also means the entire laminated structure of the protective layer 50c, the 1B polarizer 52, and the layer including the polarizer made of the protective layer 50d.

  In addition, a layer including a polarizer including the protective layer 50a, the first polarizer 51, and the protective layer 50b in this specification is also referred to as a normal polarizing plate. Accordingly, it can be said that FIG. 13A shows a stack of polarizing plates. In FIG. 13A, the transmission axes of the first polarizer 51 and the second polarizer 52 are parallel to each other and are stacked in a parallel Nicol state. Further, the extinction coefficient values of the first polarizer 51 and the second polarizer 52 are equal.

  FIG. 13B shows a layer including a stacked polarizer having a structure in which a protective layer 56a, a 1A polarizer 57, a 1B polarizer 58, and a protective layer 56b are stacked. In the case of this figure, it can be said that a pair of protective layers 56a and 56b are provided so as to sandwich the laminate of the polarizers of the first A polarizer 57 and the first B polarizer 58, and It can also be said that it is a laminate of a layer including a polarizer composed of the protective layer 56a and the first A polarizer 57 and a layer including a polarizer composed of the 1B polarizer 58 and the protective layer 56b.

  FIG. 13B is an example in which the polarizers stacked in FIG. 13A are formed in direct contact with each other without a protective layer, and is a layer including a stacked polarizer as a polarizing means. There is an advantage that the thickness of the protective layer can be reduced, and the number of protective layers can be reduced, so that the process can be simplified at low cost. In FIG. 13B, the transmission axes of the 1A polarizer 57 and the 1B polarizer 58 are parallel to each other and are stacked in a parallel Nicol state. Further, the extinction coefficients of the first A polarizer 57 and the first B polarizer 58 are equal.

  FIG. 13C illustrates an example in which polarizers are stacked with one protective layer interposed therebetween, and has a structure located between FIG. 13A and FIG. 13B. FIG. 13C illustrates a layer including a stacked polarizer having a structure in which a protective layer 60a, a 1A polarizer 61, a protective layer 60b, a 1B polarizer 62, and a protective layer 60c are stacked. Thus, the structure which laminates | stacks a protective layer and a polarizer alternately may be sufficient. In the present invention, the polarizer is in the form of a film, and can be said to be a polarizing film or a polarizing layer. In FIG. 13C, the transmission axes of the 1A polarizer 61 and the 1B polarizer 62 are parallel to each other and are stacked in a parallel Nicol state. The extinction coefficient values of the first A polarizer 61 and the first B polarizer 62 are equal.

  FIG. 13 shows an example in which two layers of polarizers are stacked, but the polarizers may be stacked in three layers or more than that, and the method of providing a protective layer is not limited to that shown in FIG. Alternatively, a structure in which the layer including the stacked polarizers illustrated in FIG. 13B is stacked on the layer including the stacked polarizers illustrated in FIG. In the case of a polarizer that is more likely to deteriorate due to moisture or temperature changes depending on the material of the polarizer, the polarizer can be further protected by covering the polarizer with a protective layer as shown in FIG. 13A, improving reliability. Can be made.

  As shown in FIG. 1, when a polarizer is provided with a layer including a display element interposed therebetween, the laminated structure of the polarizer on the viewing side may be the same as the laminated structure of the polarizer located on the opposite side with the display element interposed therebetween. And it may be different. Thus, the laminated structure of the laminated polarizers can be set as appropriate depending on the characteristics of the polarizer and the functions required of the display device. For example, in Embodiment Mode 1, a layer including a polarizer is formed by laminating layers 103 and 104 including a polarizer and layers 105 and 106 including a polarizer, respectively, and the structure thereof is illustrated in FIGS. Any of (C) may be sufficient, and a different laminated structure may be used, one being FIG. 13 (A) and the other being FIG. 13 (B).

In addition, it is good also as a structure which provides an adhesive layer (adhesion layer) in order to adhere | attach a protective layer, polarizers, and a protective layer and a polarizer as a layer containing the laminated | stacked polarizer, and laminates | stacks through it. However, in this case, the adhesive layer needs to have translucency as well as the protective layer.
In addition, a retardation film may be provided by laminating with a polarizer, and in that case, a structure in which a retardation film is provided between a pair of protective layers and laminated with a polarizer via a plurality or a single protective layer. Alternatively, a structure in which a protective layer, a retardation film, a polarizer, and a protective layer are sequentially stacked may be used.

  For example, in FIG. 13B, when the light transmitting substrate side is the protective layer 56a, a retardation film is provided between the protective layer 56a and the polarizer 57, and the phase difference is provided between the light transmitting substrate and the polarizer. A structure in which a film is provided may be employed. Furthermore, a more durable protective film or the like may be provided on the protective layer 50d, for example, as a surface protective layer, or an antireflection film that prevents reflection by external light on the screen surface, glare of the screen, and glare prevention. An anti-glare film may be provided. Moreover, when bonding the layer (polarizing plate) containing a polarizer to a board | substrate, an adhesion layer, such as an acryl type, can be used.

  The polarizer passes only light that vibrates in a certain direction and absorbs other light. For this purpose, a dichroic dye can be adsorbed and oriented on a uniaxially stretched resin film. PVA (polyvinyl alcohol) can be used as the resin. PVA has high transparency and strength, and is bonded to TAC (triacetyl cellulose) used as a protective layer (sometimes called a protective film because of its shape). Is also easy.

  As the pigment, iodine type and dye type can be used. For example, iodine-based dyes adsorb strong dichroic iodine as higher-order ions on a PVA resin film, and when stretched in an aqueous boric acid solution, iodine is arranged as a chain polymer, and the polarizer has high polarization characteristics. Indicates. On the other hand, dye-based pigments use high dichroic dyes instead of iodine, and are excellent in heat resistance and durability. In addition, iodine and dyes may be mixed and used.

  The protective layer reinforces the polarizer in strength and prevents deterioration due to temperature and humidity. As the protective layer, a film such as TAC (triacetyl cellulose), COP (cyclic olefin polymer), or PC (polycarbonate) can be used. TAC is transparent and has a low birefringence, and has excellent adhesion to PVA used in a polarizer. The COP system is a resin film having excellent heat resistance, moisture resistance and durability.

For example, as a layer containing a polarizer, an adhesive surface, TAC (triacetyl cellulose) as a protective layer, a mixed layer of PVA (polyvinyl alcohol) and iodine as a polarizer, and TAC as a protective layer are sequentially laminated from the substrate side. Other configurations can be used. The degree of polarization can be controlled by a mixed layer of PVA (polyvinyl alcohol) and iodine. Moreover, the layer (polarizing plate) containing a polarizer may be called a polarizing film from the shape.
Note that this embodiment can be used in combination with each of Embodiments 1 and 2 described above.

(Embodiment 4)
In this embodiment mode, a pair of layers including polarizers stacked in parallel Nicols is provided, and the transmission axis of the polarizer stacked in one layer and the polarized light stacked in the other layer are sandwiched between display elements. A configuration of a liquid crystal display device having a configuration in which the transmission axis of the child is arranged in crossed Nicols having a deviation will be described.

FIG. 16A is a top view illustrating a structure of a display panel according to the present invention, in which a pixel portion 2701 in which pixels 2702 are arranged in a matrix over a substrate 2700 having an insulating surface, a scan line side input terminal 2703, A signal 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 the switching element is a TFT, in which the gate electrode layer side of the TFT is connected to the scanning line and the source or drain side is connected to the signal line, so that each pixel is controlled independently by a signal input from the outside. It is possible.

  FIG. 16A shows the structure of a display panel in which signals input to the scanning lines and signal lines are controlled by an external driver circuit. As shown in FIG. 17A, a COG (Chip on The driver IC 2751 may be mounted on the substrate 2700 by the Glass method. As another mounting mode, a TAB (Tape Automated Bonding) method as shown in FIG. 17B 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. 17, a driver IC 2751 is connected to an FPC (Flexible printed circuit) 2750.

  In the case where the TFT provided for the pixel is formed using a crystalline semiconductor, the scan line driver circuit 3702 can be formed over the substrate 3700 as shown in FIG. In FIG. 16B, the pixel portion 3701 is controlled by an external driver circuit as in FIG. 16A 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. 16C, 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.

FIG. 14A is a top view of a liquid crystal display device having a layer including stacked polarizers, and FIG. 14B is a cross-sectional view taken along line CD in FIG.
As shown in FIG. 14A, a pixel region 606, a driver circuit region 608a, and a driver circuit region 608b are sealed between a substrate 600 and a counter substrate 695 by a sealant 692, and an IC driver is formed over the substrate 600. A signal line driver circuit 607 formed by the above is provided.

The pixel region 606 is provided with a transistor 622 and a capacitor 623, and the driver circuit region 608b is provided with a driver circuit including a transistor 620 and a transistor 621. For the substrate 600, an insulating substrate similar to that in Embodiment 1 can be used. In general, a substrate made of a synthetic resin is feared to have a lower heat-resistant temperature than other substrates, but it is also adopted by transposing after a manufacturing process using a substrate with high heat resistance. It becomes possible.
Further, a transistor 622 serving as a switching element is provided in the pixel region 606 with the base film 604a and the base film 604b interposed therebetween.

  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 called an LDD (Light doped drain) structure. The low concentration impurity region can be formed so as to overlap with the gate electrode, and such a thin film transistor is referred to as a GOLD (Gate Overlaped 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).

  Further, in order to 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, aluminum oxide, diamond-like carbon (DLC), polysilazane, nitrogen content with nitrogen content higher than oxygen 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 aryl group) 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.

  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.

These transistors are not limited to this embodiment mode, and a thin film transistor in a pixel region has 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. There may be. 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.
Further, these transistors are not limited to the structure and manufacturing method of the thin film transistor described in this embodiment mode, and are top gate type (eg, forward stagger type), bottom gate type (eg, inverted stagger type), or 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 a gate insulating film.

  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 695 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, and a substrate 600 which is a TFT substrate are interposed through a spacer 637. The liquid crystal layer 632 is provided in the gap by bonding. After that, a layer 641 including a first A polarizer and a layer 642 including a 1B polarizer are provided outside the counter substrate 695, and the second A polarizer is provided on the opposite side of the substrate 600 having the element. A layer 643 and a layer 644 including a second-B polarizer are provided.

  The layer containing these polarizers 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. 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.

  Note that a color filter may not be provided when an RGB light emitting diode (LED) or the like is disposed in the backlight and a continuous additive color mixing method (field sequential method) in which color display is performed by time division is employed. 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 interposed in the liquid crystal layer may be a method in which particles of several μm are dispersed and provided, 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.
Thereafter, 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. As the shape of the spacer material, a conical shape, a pyramid shape, or the like can be used, 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 various conductive materials such as a metal oxide, an organometallic compound, a metal, or an alloy can be used for the wiring included in the transistor, the gate electrode layer, the pixel electrode layer 630, and the conductive layer 634 that is a counter electrode.

As the conductive material, indium tin oxide (ITO), IZO (indium zinc oxide) in which zinc oxide (ZnO) is mixed with indium oxide, conductive material in which silicon oxide (SiO ₂ ) is mixed with indium oxide, organic indium, Organic tin, indium oxide including tungsten oxide, indium zinc oxide including tungsten oxide, indium oxide including titanium oxide, indium tin oxide including titanium oxide, 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 (Al ), Metals such as copper (Cu), silver (Ag) or alloys thereof, or metal nitrides thereof. It is possible.

The substrate 600 is provided with a layer 643 including a second A polarizer and a layer 644 including a 2B polarizer, and the counter substrate 695 also includes a layer 641 and a first B including a 1A polarizer. A layer 642 including a polarizer is stacked. The layer 643 including the second A polarizer provided on the backlight side and the layer 644 including the second B polarizer are stacked so that the transmission axes thereof are parallel Nicols, and the first A polarized light provided on the viewing side. The layer 641 including the polarizer and the layer 642 including the first-B polarizer are also arranged so that their transmission axes are parallel Nicols.
On the other hand, the transmission axis of the layer 643 including the 2A polarizer and the layer 644 including the 2B polarizer, and the layer 641 including the 1A polarizer and the layer including the 1B polarizer provided on the viewing side. The transmission axis 642 is arranged in a crossed Nicol with a deviation.

The present invention is characterized in that the pair of layers of the stacked polarizers are arranged in crossed Nicols in which the transmission axes of the polarizers of the respective layers are displaced with the display element interposed therebetween. As a result, the contrast ratio can be increased.
In the present embodiment, the extinction coefficient of the absorption axis of the layer 641 including the 1A polarizer and the layer 642 including the 1B polarizer are the same. Similarly, the extinction coefficient of the absorption axis of the layer 643 including the 2A polarizer and the layer 644 including the 2B polarizer are the same.

The layer 643 including the second 2A polarizer and the layer 644 including the 2B polarizer, and the layer 641 including the first 1A polarizer and the layer 642 including the 1B polarizer are stacked on the substrate 600, respectively. The counter substrate 695 is bonded.
Moreover, you may laminate | stack in the state which had the phase difference film between the layer containing the laminated | stacked polarizer, and a board | substrate.

In the present invention, the liquid crystal display device is provided with a pair of layers including polarizers stacked in parallel Nicols, and the transmission axes of the polarizers of the respective layers are arranged in crossed Nicols having a deviation. The contrast ratio can be increased.
Note that Embodiment 4 can be freely combined with Embodiments 1 to 3 described above.

(Embodiment 5)
In this embodiment mode, a liquid crystal display device using a thin film transistor having an amorphous semiconductor film, which is different from that in Embodiment Mode 4, is described.

  In the display device illustrated in FIG. 15, a transistor 220 that is an inverted staggered thin film transistor, a pixel electrode layer 201, an insulating layer 202, an insulating layer 203, a liquid crystal layer 204, a spacer 281, an insulating layer 205, a counter region, The electrode layer 206, the color filter 208, the black matrix 207, the counter substrate 210, the layer 231 including the first A polarizer, the layer 232 including the first B polarizer, and the second A layer on the opposite surface of the substrate 200, that is, the lower surface. A layer 233 including a polarizer, a layer 234 including a second-B polarizer, and a sealing material 282, a terminal electrode layer 287, an anisotropic conductive layer 285, and an FPC 286 are provided in a sealing region.

  A gate electrode layer, a source electrode layer, and a drain electrode layer of the transistor 220 which is an inverted staggered thin film transistor manufactured in this embodiment are formed by a droplet discharge method. The droplet discharge method is a method in which a composition having a liquid conductive material is discharged and solidified by drying or baking to form a conductive layer or an electrode layer. An insulating layer can also be formed by discharging a composition containing an insulating material and solidifying it by drying or baking. Since a structure of the display device such as a conductive layer or an insulating layer can be formed selectively, the process can be simplified and material loss can be prevented, so that the display device can be manufactured with low cost and high productivity.

In this embodiment mode, an amorphous semiconductor is used as a semiconductor layer, and a semiconductor layer having one conductivity type may be formed as needed. In this embodiment mode, an amorphous n-type semiconductor layer is stacked as a semiconductor layer and a semiconductor layer having one conductivity type.
In order to impart conductivity, an element imparting conductivity is added by doping, and an impurity region is formed in the semiconductor layer, whereby an n-channel thin film transistor or a P-channel thin film transistor can be formed. Instead of forming the n-type semiconductor layer, conductivity may be imparted to the semiconductor layer by performing plasma treatment with PH ₃ gas.
In this embodiment, the transistor 220 is an n-channel inverted staggered thin film transistor. Alternatively, a channel-protective inverted staggered thin film transistor in which a protective layer is provided over the channel region of the semiconductor layer can be used.

  As the semiconductor, an organic semiconductor material can be used and formed by an evaporation method, a printing method, a spray method, a spin coating method, a droplet discharge method, a dispenser method, or the like. In this case, since the etching process is not necessarily required, the number of processes can be reduced. As the organic semiconductor, a low molecular material such as pentacene, a polymer material, or the like is used, and materials such as an organic dye or a conductive polymer material can also be used. The organic semiconductor material used in the present invention is preferably a π-electron conjugated polymer material whose skeleton is composed of conjugated double bonds. Typically, a soluble polymer material such as polythiophene, polyfluorene, poly (3-alkylthiophene), or a polythiophene derivative can be used.

Next, the configuration of the backlight unit 352 will be described. The backlight unit 352 includes a cold cathode tube, a hot cathode tube, a light emitting diode, an inorganic EL, and an organic EL as a light source 331 that emits fluorescence, a lamp reflector 332 for efficiently guiding the fluorescence to the light guide plate 335, and the fluorescence is totally reflected. However, the light guide plate 335 for guiding light to the entire surface, the diffusion plate 336 for reducing unevenness in brightness, and the reflection plate 334 for reusing light leaked under the light guide plate 335 are configured. .
A control circuit for adjusting the luminance of the light source 331 is connected to the backlight unit 352, and the luminance of the light source 331 can be controlled by supplying a signal from the control circuit.

A layer 233 including a 2A polarizer and a layer 234 including a 2B polarizer are stacked between the substrate 200 and the backlight unit 352, and the counter substrate 210 also includes the 1A polarizer. A layer 231 and a layer 232 including a 1B polarizer are stacked. The layer 233 including the 2A polarizer and the layer 234 including the 2B polarizer provided on the backlight side are stacked such that the transmission axes thereof are parallel Nicols, and the first A polarization provided on the viewing side. The layer 231 including the polarizer and the layer 232 including the first-B polarizer are also arranged so that their transmission axes are parallel Nicols.
On the other hand, the transmission axis of the layer 233 including the 2A polarizer and the layer 234 including the 2B polarizer, and the layer 231 including the 1A polarizer and the layer including the 1B polarizer provided on the viewing side. The transmission axis of 232 is arranged in crossed Nicols with a deviation.

The present invention is characterized in that the transmission axes of the polarizers in each of the pair of layers including the polarizers laminated as described above are arranged in crossed Nicols having a gap across the display element.
As a result, the contrast ratio can be increased. In the present embodiment, the extinction coefficient of the absorption axis of the layer 231 including the 1A polarizer and the layer 232 including the 1B polarizer are the same, and similarly, the layer 233 including the 2A polarizer. The extinction coefficient of the absorption axis of the layer 234 including the second B polarizer is also the same.

  The layer 233 including the 2A polarizer and the layer 234 including the 2B polarizer, and the layer 231 including the 1A polarizer and the layer 232 including the 1B polarizer are respectively formed on the substrate. 200 and the counter substrate 210. Moreover, you may laminate | stack in the state which had the phase difference film between the layer containing the laminated | stacked polarizer, and a board | substrate.

In the present invention, a pair of layers including a plurality of polarizers whose transmission axes are stacked in parallel Nicols are provided for the liquid crystal display device in this way, and the transmission axes of the polarizers of each layer are changed to crossed Nicols having a deviation. By arranging, the contrast ratio can be increased.
Note that Embodiment 5 can be freely combined with Embodiments 1 to 4 described above.

(Embodiment 6)
In this embodiment mode, operations of circuits and the like included in the display device are described.
FIG. 24 is a system block diagram of the pixel portion 505 and the driver circuit portion 508 of the display device.
The pixel portion 505 includes a plurality of pixels, and a switching element is provided in an intersection region between the signal line 512 serving as each pixel and the scanning line 510.

  Application of a voltage for controlling the tilt of liquid crystal molecules can be controlled by this switching element. A structure in which switching elements are provided in each intersection region in this way is called an active type. The pixel portion of the present invention is not limited to such an active type, and may have a passive configuration. The passive type has a simple process because there is no switching element in each pixel.

  The driver circuit portion 508 includes a control circuit 502, a signal line driver circuit 503, and a scanning line driver circuit 504. The control circuit 502 to which the video signal 501 is input has a function of performing gradation control according to the display content of the pixel portion 505. Therefore, the control circuit 502 inputs the generated signal to the signal line driver circuit 503 and the scan line driver circuit 504. When a switching element is selected via the scanning line 510 based on the scanning line driving circuit 504, a voltage is applied to the pixel electrode in the selected intersection region. The value of this voltage is determined based on a signal input from the signal line driver circuit 503 via the signal line.

  Further, the control circuit 502 generates a signal for controlling the power supplied to the lighting unit 506, and the signal is input to the power source 507 of the lighting unit 506. As the lighting means, the backlight unit described in Embodiment Mode 5 can be used. The illumination means includes a front light in addition to the backlight. The front light is a plate-like light unit that is mounted on the front side of the pixel portion and is configured by a light emitter and a light guide that illuminate the whole. Such illumination means can illuminate the pixel portion evenly with low power consumption.

As illustrated in FIG. 24B, the scan line driver circuit 504 includes circuits that function as a shift register 541, a level shifter 542, and a buffer 543. Signals such as a gate start pulse (GSP) and a gate clock signal (GCK) are input to the shift register 541. Note that the scan line driver circuit of the present invention is not limited to the structure shown in FIG.
As shown in FIG. 24C, the signal line driver circuit 503 includes circuits that function as a shift register 531, a first latch 532, a second latch 533, a level shifter 534, and a buffer 535.

  The circuit functioning as the buffer 535 is a circuit having a function of amplifying a weak signal and includes an operational amplifier or the like. Signals such as a start pulse (SSP) and a clock signal (SCK) are input to the shift register 531, and data (DATA) such as a video signal is input to the first latch 532. A latch (LAT) signal can be temporarily held in the second latch 533 and is input to the pixel portion 505 all at once. This is called line sequential driving. Therefore, the second latch can be omitted if the pixel performs dot sequential driving instead of line sequential driving. As described above, the signal line driver circuit of the present invention is not limited to the structure shown in FIG.

  The signal line driver circuit 503, the scan line driver circuit 504, and the pixel portion 505 can be formed using semiconductor elements provided over the same substrate. The semiconductor element can be formed using a thin film transistor provided over a glass substrate. In this case, a crystalline semiconductor film is preferably used for the semiconductor element (see Embodiment Mode 4). Since the crystalline semiconductor film has high electrical characteristics, particularly mobility, a circuit included in the driver circuit portion can be formed. Further, the signal line driver circuit 503 and the scanning line driver circuit 504 can be mounted on a substrate by using an IC (Integrated Circuit) chip. In this case, an amorphous semiconductor film can be applied to the semiconductor element in the pixel portion (see Embodiment Mode 5).

  In such a display device, a pair of layers including polarizers stacked in parallel Nicols are provided, and the polarizers of the respective layers are arranged in crossed Nicols having a gap across the display element, thereby increasing the contrast ratio. Can do. That is, the contrast ratio of light from the illumination means controlled by the control circuit can be increased.

(Embodiment 7)
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. 19A, 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. 19B, 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.

  Further, as shown in FIG. 19C, 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. 19D, when light-emitting diodes (LEDs) 403, 404, and 405 of each color RGB are used as the light source, it is not necessary to have the same number and arrangement. 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, or 405 of each color RGB may be used in combination.
Note that in the case of having RGB light emitting diodes, when the field sequential mode is applied, color display can be performed by sequentially turning on the RGB light emitting diodes according to time.

As described above, when a light-emitting diode is used, since luminance is high, it 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.
Furthermore, the light source is not necessarily arranged 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.

  For a display device using such a backlight, a pair of layers including polarizers stacked in parallel Nicols is provided, and the polarizers of the respective layers are arranged in crossed Nicols with the transmission axis shifted with the display element interposed therebetween. By doing so, an image with a high contrast ratio can be provided. In particular, a backlight having 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.

(Embodiment 8)
As a method of driving the liquid crystal in the liquid crystal display device, there are a vertical electric field method in which a voltage is applied in a direction perpendicular to the substrate and a horizontal electric field method in which a voltage is applied in parallel with the substrate. A configuration in which a pair of layers including stacked polarizers are arranged in crossed Nicols with the transmission axes of the polarizers in each layer being shifted applies to both a vertical electric field method and a horizontal electric field method. Can do.

Therefore, in this embodiment mode, various liquid crystal modes applicable to a display device in which a pair of layers including polarizers stacked in parallel Nicols and crossed Nicols in which the polarizers of each layer are shifted are described. .
First, FIGS. 10A1 and 10A2 are schematic views of a TN mode liquid crystal display device.

As in Embodiment 1 described above, the layer 100 having a display element is sandwiched between the first substrate 101 and the second substrate 102 which are arranged to face each other. A layer 103 including a first A polarizer and a layer 104 including a 1B polarizer are stacked in a parallel Nicol state on the first substrate 101 side, and a second A layer is stacked on the second substrate 102 side. A layer 105 including a polarizer and a layer 106 including a second-B polarizer are stacked in a parallel Nicol state.
Further, the transmission axis of the layer 103 including the 1A polarizer and the layer 104 including the 1B polarizer, and the transmission axis of the layer 105 including the 2A polarizer and the layer 106 including the 2B polarizer are as follows. It is arranged in crossed Nicols with a gap.

  Although not illustrated, the backlight or the like is disposed outside the layer including the second-B polarizer, and the first electrode 108 and the second electrode 102 are provided on the first substrate 101 and the second substrate 102, respectively. The electrode 109 is provided. Further, the first electrode 108 which is the electrode on the side opposite to the backlight, that is, the viewing side is formed so as to have at least translucency.

In the liquid crystal display device having such a structure, in the normally white mode, when voltage is applied to the first electrode 108 and the second electrode 109 (referred to as a vertical electric field mode), the state illustrated in FIG. As shown, black display is performed. At this time, the liquid crystal molecules are aligned vertically, and the light from the backlight cannot pass through the substrate, resulting in a black display.
On the other hand, as shown in FIG. 10A2, when a voltage is not applied between the first electrode 108 and the second electrode 109, white display is performed. At this time, the liquid crystal molecules are aligned horizontally and are rotated in a plane.

As a result, the light from the backlight can pass through a pair of layers including polarizers stacked in parallel Nicols, which are arranged in crossed Nicols having a deviation, and a predetermined video display is performed.
At this time, full color display can be performed by providing a color filter. The color filter can be provided on either the first substrate 101 side or the second substrate 102 side.
In addition, what is necessary is just to use a well-known thing as the liquid-crystal material used for TN mode.

FIG. 10B1 is a schematic diagram of a VA mode liquid crystal display device. The VA mode is a mode in which liquid crystal molecules are aligned so as to be perpendicular to the substrate when there is no electric field.
Similarly to FIGS. 10A1 and 10A2, a first electrode 108 and a second electrode 109 are provided over the first substrate 101 and the second substrate 102, respectively. In addition, the first electrode 108 which is an electrode on the side opposite to the backlight, that is, the viewing side is formed so as to have at least translucency. A layer 100 having a display element is sandwiched between a first substrate 101 and a second substrate 102 which are arranged so as to face each other.

A layer 103 including a 1A polarizer and a layer 104 including a 1B polarizer are stacked in parallel Nicols on the first substrate 101 side, and a second A polarization is stacked on the second substrate 102 side. A layer 105 including a polarizer and a layer 106 including a second-B polarizer are stacked so as to be parallel Nicols.
Further, the transmission axis of the layer 103 including the 1A polarizer and the layer 104 including the 1B polarizer, and the transmission axis of the layer 105 including the 2A polarizer and the layer 106 including the 2B polarizer are as follows. , Have a gap and are arranged in crossed Nicols.

In the liquid crystal display device having such a structure, when voltage is applied to the first electrode 108 and the second electrode 109 (vertical electric field method), white display is performed as illustrated in FIG. It becomes a state. At this time, the liquid crystal molecules are arranged side by side, and the light from the backlight can pass through a pair of layers including polarizers stacked in parallel Nicols arranged in crossed Nicols with a gap. A predetermined video display is performed.
Note that at this time, full color display can be performed by providing a color filter, and the color filter can be provided on either the first substrate 101 side or the second substrate 102 side.

Then, as shown in FIG. 10B2, when a voltage is not applied between the first electrode 108 and the second electrode 109, black display, that is, an off state is obtained. At this time, the liquid crystal molecules are aligned vertically. As a result, the light from the backlight cannot pass through the substrate, resulting in a black display.
In such an off state, the liquid crystal molecules rise perpendicular to the substrate and display black, and in the on state, the liquid crystal molecules tilt horizontally with respect to the substrate and display white.

  Since the liquid crystal molecules are standing up in the above-described OFF state, the light from the polarized backlight passes through the cell without being affected by the birefringence of the liquid crystal molecules, and is a layer including a polarizer on the counter substrate side. Can be completely blocked. Therefore, it has a pair of layers including polarizers stacked in parallel Nicols, and the transmission axes of the polarizer stacked in one layer and the polarizer stacked in the other layer with the display element interposed therebetween are shifted. It is expected that the contrast ratio will be further improved due to the arrangement of the crossed Nicols.

FIGS. 10C1 and 10C2 illustrate an example in which the layer including the stacked polarizers used in the present invention is applied to the MVA mode in which the alignment of the liquid crystal is divided. The MVA mode is a method in which one pixel is divided into a plurality of parts and the viewing angle dependence of each part is compensated for each other.
As shown in FIG. 10C1, in the MVA mode, protrusions 158 and 159 having a triangular cross section are provided on the first electrode 108 and the second electrode 109 for alignment control. When voltage is applied to the first electrode 108 and the second electrode 109 (vertical electric field method), an on state in which white display is performed is performed as illustrated in FIG.

At this time, the liquid crystal molecules are in a state of being tilted and arranged with respect to the protrusions 158 and 159. As a result, light from the backlight can pass through a pair of layers including polarizers stacked in parallel Nicols arranged in crossed Nicols with a deviation, and a predetermined video display is performed.
Note that a full color display can be performed by providing a color filter at this time, and the color filter can be provided on either the first substrate 101 side or the second substrate 102 side.

  Then, as shown in FIG. 10C2, when a voltage is not applied between the first electrode 108 and the second electrode 109, black display, that is, an off state is obtained. At this time, the liquid crystal molecules are aligned vertically, and as a result, the light from the backlight cannot pass through the substrate, resulting in a black display.

  FIG. 7 shows a top view and a cross-sectional view of another example of the MVA mode. In FIG. 7A, the second electrode is formed in a bent pattern like a dogleg shape, and becomes the second electrodes 109a, 109b, and 109c. An insulating layer 162 that is an alignment film is formed over the second electrodes 109a, 109b, and 109c. As shown in FIG. 7B, a protrusion 158 is formed on the first electrode 108 so as to correspond to the second electrodes 109a, 109b, and 109c. The openings of the second electrodes 109a, 109b, and 109c function like protrusions and can move liquid crystal molecules.

11A1 and 11A2 are schematic views of an OCB mode liquid crystal display device. In the OCB mode, the alignment of liquid crystal molecules forms an optically compensated state in the liquid crystal layer, which is called bend alignment.
Similar to FIG. 10, a first electrode 108 and a second electrode 109 are provided over the first substrate 101 and the second substrate 102, respectively. Although not shown, a backlight or the like is disposed outside the layer 106 including the second-B polarizer. The first electrode 108 which is an electrode on the side opposite to the backlight, that is, the viewing side is formed to have at least translucency.
A layer 100 having a display element is sandwiched between a first substrate 101 and a second substrate 102 which are arranged so as to face each other.

A layer 103 including a 1A polarizer and a layer 104 including a 1B polarizer are stacked in parallel Nicols on the first substrate 101 side, and a second A polarization is stacked on the second substrate 102 side. A layer 105 including a polarizer and a layer 106 including a second-B polarizer are stacked so as to be parallel Nicols.
Further, the transmission axis of the layer 103 including the 1A polarizer and the layer 104 including the 1B polarizer, and the transmission axis of the layer 105 including the 2A polarizer and the layer 106 including the 2B polarizer are as follows. , Arranged in crossed Nicol with a gap.

In a liquid crystal display device having such a structure, when a constant on-voltage is applied to the first electrode 108 and the second electrode 109 (vertical electric field method), black display is generated as shown in FIG. Done. At this time, the liquid crystal molecules are aligned vertically. Then, the light from the backlight cannot pass through the substrate, and a black display is obtained.
On the other hand, as shown in FIG. 11A2, when a constant off voltage is applied between the first electrode 108 and the second electrode 109, white display is performed. At this time, the liquid crystal molecules are in a bend alignment state.

As a result, light from the backlight can pass through a pair of layers including polarizers stacked in parallel Nicols arranged in crossed Nicols having a deviation, and a predetermined video display is performed. At this time, a full color display can be performed by providing a color filter. The color filter can be provided on either the first substrate 101 side or the second substrate 102 side.
In such an OCB mode, the alignment of liquid crystal molecules can be optically compensated in the liquid crystal layer, so that the viewing angle dependence is small, and the contrast ratio can be increased by a pair of layers including stacked polarizers.

FIGS. 11B1 and 11B2 are schematic diagrams of liquid crystals in the FLC mode and the AFLC mode.
Similar to FIG. 10, a first electrode 108 and a second electrode 109 are provided over the first substrate 101 and the second substrate 102, respectively. The first electrode 108 which is an electrode on the side opposite to the backlight, that is, the viewing side is formed so as to have at least translucency. A layer 100 having a display element is sandwiched between a first substrate 101 and a second substrate 102 which are arranged so as to face each other.

A layer 103 including a 1A polarizer and a layer 104 including a 1B polarizer are stacked in parallel Nicols on the first substrate 101 side, and a second A polarization is stacked on the second substrate 102 side. A layer 105 including a polarizer and a layer 106 including a second-B polarizer are stacked so as to be parallel Nicols.
Further, the transmission axis of the layer 103 including the 1A polarizer and the layer 104 including the 1B polarizer, and the transmission axis of the layer 105 including the 2A polarizer and the layer 106 including the 2B polarizer are as follows. , Arranged in crossed Nicol with a gap.

  In the liquid crystal display device having such a structure, when voltage is applied to the first electrode 108 and the second electrode 109 (referred to as a vertical electric field mode), white display is performed as illustrated in FIG. . At this time, the liquid crystal molecules are arranged side by side in a direction shifted from the rubbing direction. As a result, the light from the backlight can pass through a pair of layers including polarizers stacked in parallel Nicols and arranged in crossed Nicols with a deviation, and a predetermined video display is performed.

Then, as shown in FIG. 11B2, when no voltage is applied between the first electrode 108 and the second electrode 109, black display is performed. At this time, the liquid crystal molecules are arranged side by side along the rubbing direction. As a result, the light from the backlight cannot pass through the substrate, resulting in a black display.
Note that full color display can be performed by providing a color filter at this time, and the color filter can be provided on either the first substrate 101 side or the second substrate 102 side.
As the liquid crystal material used for the FLC mode and the AFLC mode, a known material may be used.

12A1 and 12A2 are schematic views of an IPS mode liquid crystal display device. The IPS mode is a mode in which liquid crystal molecules are always rotated in a plane with respect to a substrate, and an electrode adopts a horizontal electric field method provided only on one substrate side.
The IPS mode is characterized in that the liquid crystal is controlled by a pair of electrodes provided on one substrate. Therefore, a pair of electrodes 150 and 151 is provided over the second substrate 102. The pair of electrodes 150 and 151 preferably have a light-transmitting property.

A layer 100 having a display element is sandwiched between a first substrate 101 and a second substrate 102 which are arranged so as to face each other. A layer 103 including a first A polarizer and a layer 104 including a 1B polarizer are stacked in parallel Nicols on the first substrate 101 side, and a second A polarizer is stacked on the second substrate 102 side. The layer 105 including the layer 2 and the layer 106 including the second-B polarizer are stacked so as to be parallel Nicols.
Further, the transmission axis of the layer 103 including the 1A polarizer and the layer 104 including the 1B polarizer, and the transmission axis of the layer 105 including the 2A polarizer and the layer 106 including the 2B polarizer are as follows. , Arranged in crossed Nicol with a gap.

In the liquid crystal display device having such a structure, when a voltage is applied to the pair of electrodes 150 and 151, the liquid crystal molecules are aligned along the lines of electric force deviated from the rubbing direction as shown in FIG. The white display is turned on, and the light from the backlight can pass through a pair of layers including polarizers stacked in parallel Nicols, arranged in crossed Nicols with a deviation, and a predetermined video display Is done.
Note that a full color display can be performed by providing a color filter at this time, and the color filter can be provided on either the first substrate 101 side or the second substrate 102 side.

  Further, as shown in FIG. 12A2, when a voltage is not applied between the pair of electrodes 150 and 151, black display, that is, an off state is obtained. At this time, the liquid crystal molecules are arranged side by side along the rubbing direction. As a result, the light from the backlight cannot pass through the substrate, resulting in a black display.

  An example of a pair of electrodes 150 and 151 that can be used in the IPS mode is shown in FIG. As shown in the top views of FIGS. 8A to 8D, the pair of electrodes 150 and 151 are formed so as to alternate with each other. In FIG. 8A, the electrode 150a and the electrode 151a are wavy with undulations. In FIG. 8B, the electrode 150b and the electrode 151b have concentric openings, and in FIG. 8C, the electrode 150c and the electrode 151c are comb-shaped and partially overlapped. In FIG. 8D, the electrode 150d and the electrode 151d have a comb-like shape and have a shape in which the electrodes are engaged with each other.

  In addition to the IPS mode, an FFS mode can also be used. In the FFS mode, the pair of electrodes are formed on the same surface in the IPS mode, whereas the pair of electrodes are not formed on the same surface, and are insulated on the electrode 152 as shown in FIGS. 12B1 and 12B2. In this structure, the electrode 153 is formed through a film.

In the liquid crystal display device having such a structure, when voltage is applied to the pair of electrodes 152 and 153, white display is performed as illustrated in FIG. 12B1, and light from the backlight is A pair of layers including polarizers stacked in parallel Nicols, which are arranged in crossed Nicols having a deviation, can pass through, and a predetermined video display is performed.
Note that at this time, full color display can be performed by providing a color filter, and the color filter can be provided on either the first substrate 101 side or the second substrate 102 side.

  On the other hand, as shown in FIG. 12B2, when no voltage is applied between the pair of electrodes 152 and 153, black display, that is, an off state is established. At this time, the liquid crystal molecules are arranged side by side and rotated in a plane. As a result, the light from the backlight cannot pass through the substrate, resulting in a black display.

An example of a pair of electrodes 152 and 153 that can be used in the FFS mode is shown in FIG. As shown in the top views in FIGS. 9A to 9D, electrodes 153 formed in various patterns are formed on the electrode 152. In FIG. 9A, the electrode 153a on the electrode 152a is bent. In FIG. 9B, the electrode 153b on the electrode 152b has a concentric shape, and in FIG. 9C, the electrode 153c on the electrode 152c has a comb-like shape so that the electrodes are engaged with each other. In FIG. 9D, the electrode 153d on the electrode 152d has a comb-like shape.
In addition, what is necessary is just to use a well-known thing as the liquid-crystal material used for IPS mode and FFS mode.

  The transmission axis of a polarizer including a pair of polarizers stacked in parallel Nicol as employed in the present invention, with one layer sandwiched between display elements and the other layer stacked polarizer When the arrangement of the crossed Nicols with a deviation is applied to a vertical electric field liquid crystal display device, display with a higher contrast ratio can be performed. Such a vertical electric field method is suitable for a computer display device or a large television used indoors.

When the present invention is applied to a horizontal electric field liquid crystal display device, a display with a high contrast ratio can be achieved in addition to a wide viewing angle. Such a horizontal electric field method is suitable for a portable display device, a television device, and the like.
In addition, the present invention can be applied to an optical rotation mode, a scattering mode, a birefringence mode liquid crystal display device, and a display device in which layers including a polarizer are arranged on both sides of a substrate.
Further, this embodiment can be freely combined with Embodiments 1 to 7 described above.

(Embodiment 9)
This embodiment will be described with reference to FIGS. 18A and 18B. FIG. 18A and FIG. 18B illustrate an example in which a display device (a liquid crystal display module) is formed using a TFT substrate 2600 manufactured by applying the present invention.
FIG. 18A 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 or the like and a liquid crystal layer 2604 are provided therebetween to form a display region. ing.

  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. Outside the TFT substrate 2600 and the counter substrate 2601 are a layer 2607 containing a 2A polarizer, a layer 2627 containing a 2B polarizer, a diffuser plate 2613, and a layer 2606 containing a 1A polarizer, respectively. A layer 2626 including a polarizer is disposed. 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.

A layer 2607 including a 2A polarizer and a layer 2627 including a 2B polarizer are provided between the TFT substrate 2600 and a backlight as a light source, and the 1A polarizer is also provided on the counter substrate 2601. A layer 2606 including a layer and a layer 2626 including a first-B polarizer are stacked.
A layer 2607 including a 2A polarizer and a layer 2627 including a 2B polarizer provided on the backlight side are stacked so that their transmission axes are parallel Nicols, and the first A 1A provided on the viewer side is provided. The layer 2606 including the polarizer and the layer 2626 including the first-B polarizer are also arranged so that their transmission axes are parallel Nicols.

Then, the transmission axis of the layer 2607 including the 2A polarizer and the layer 2627 including the 2B polarizer, the layer 2606 including the 1A polarizer provided on the viewing side, and the layer including the 1B polarizer. The transmission axis of 2626 is arranged in crossed Nicols having a deviation.
As described above, in the present invention, the transmission axes of the polarizers in each of the pair of layers including the stacked polarizers are arranged in crossed Nicols having a gap across the display element. And As a result, the contrast ratio can be increased. In the present embodiment, the extinction coefficient of the absorption axis of the layer 2606 including the 1A polarizer and the layer 2626 including the 1B polarizer are the same. Similarly, the extinction coefficient of the absorption axis of the layer 2607 containing the 2A polarizer and the layer 2627 containing the 2B polarizer are the same.

  The layer 2607 including the 2A polarizer and the layer 2627 including the 2B polarizer, and the layer 2606 including the 1A polarizer and the layer 2626 including the 1B polarizer are stacked on the TFT substrate. 2600 and the counter substrate 2601 are bonded to each other. In addition, it is preferable to stack with a retardation film between the layer including the polarizer and the substrate. Further, if necessary, the layer 2626 including the first-B polarizer provided on the viewing side may be subjected to an antireflection treatment.

  Liquid crystal modes that can be used in the liquid crystal display module of the present invention are shown below. For example, TN (Twisted Nematic) mode, IPS (In-Plane-Switching) mode, FFS (Fringe Field Switching) mode, VA (Vertical Alignment) mode, MVA (Multi-domain Vertical Alignment) mode, PVA ( Patterned vertical alignment (ASM), ASM (Axially Symmetric aligned Micro-cell) mode, OCB (Optical Compensated Birefringence) mode, FLC (Ferroelectric Liquid Crystal) mode, AFLC (Anti Ferroelectric Liquid Crystal), etc. can be used.

FIG. 18B is an example in which the OCB mode is applied to the liquid crystal display module of FIG. 18A, 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 all three colors can be displayed in any area. On the other hand, since three colors of light are emitted 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 mode, HV (Half V) -FLC, SS (Surface Stabilized) -FLC using a ferroelectric liquid crystal (FLC) capable of high-speed operation 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. 18B 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.

Also in the ninth embodiment, as described above, the pair of polarizers stacked in parallel Nicols are arranged in crossed Nicols in which the transmission axes of the polarizers of the respective layers are shifted, so that Light leakage can be reduced. For this reason, the contrast ratio of the display device can be increased. Thus, a high-performance and high-quality display device can be manufactured.
Note that this embodiment can be used in combination with each of Embodiments 1 to 8 described above.

(Embodiment 10)
This embodiment will be described with reference to FIG. FIG. 23 shows an example in which a display device is formed using a substrate 813 which is a TFT substrate manufactured by applying the present invention.
23 includes a substrate 813, a pixel portion 814 including a TFT, a liquid crystal layer 815, a counter substrate 816, a layer 817 including a 1A polarizer, a layer 818 including a 1B polarizer, and a 2A polarizer. A display unit 801 including a layer 811, a layer 812 including a second-B polarizer, a slit (grating) 850, a driver circuit 819, and an FPC 837; A backlight unit 803 including 836 is shown.

The display device of the present invention shown in FIG. 23 can perform three-dimensional display without using special equipment such as glasses. The slit 850 having an opening disposed on the backlight unit side transmits light incident from the light source in a stripe shape and allows the light to enter the display device unit 801. The slit 850 can create a parallax between both eyes of the viewer on the viewer side, and the viewer sees only the right-eye pixel in the right eye and the left-eye pixel in the left eye at the same time.
As described above, the viewer can see the three-dimensional display. That is, in the display device unit 801, the light given a specific viewing angle by the slit 850 passes through pixels corresponding to the right-eye image and the left-eye image, so that the right-eye image and the left-eye image are different. Separated into viewing angles, three-dimensional display is performed.

Between the substrate 813 and the backlight as the light source, a layer 811 including a 2A polarizer and a layer 812 including a 2B polarizer are stacked, and the 1A polarizer is also provided on the counter substrate 816. And a layer 818 including a first-B polarizer are stacked.
The layer 811 including the second A polarizer and the layer 812 including the second B polarizer provided on the backlight side are stacked so that the transmission axes thereof are parallel Nicols, and the first A first layer provided on the viewer side is provided. The layer 817 including the polarizer and the layer 818 including the first-B polarizer are also arranged so that their transmission axes are parallel Nicols.

  Then, the transmission axis of the layer 811 including the 2A polarizer and the layer 812 including the 2B polarizer, the layer 817 including the 1A polarizer and the layer including the 1B polarizer provided on the viewing side. The transmission axis 818 is arranged in a crossed Nicol with a deviation. The present invention is characterized in that the transmission axes of the polarizers in each of a pair of layers of the stacked polarizers are arranged in crossed Nicols having a gap across the display element.

As a result, the contrast ratio can be increased. If an electronic device such as a television device or a cellular phone is manufactured using the display device of the present invention, a high-functional and high-quality electronic device capable of performing three-dimensional display can be provided.
In the present embodiment, the extinction coefficient of the absorption axis of the layer 817 including the 1A polarizer and the layer 818 including the 1B polarizer are the same, and similarly, the layer 811 including the 2A polarizer. The extinction coefficient of the absorption axis of the layer 812 including the second B polarizer is also the same.

(Embodiment 11)
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. 20 is a block diagram illustrating a main configuration of the television device.

  In the display panel, only the pixel portion 701 is formed as shown in FIG. 16A, and the scan line side driver circuit 703 and the signal line side driver circuit 702 are combined with a TAB method as shown in FIG. In the case of mounting by the COG method as shown in FIG. 17A, the TFT is formed as shown in FIG. 16B, and the pixel portion 701 and the scanning line side driver circuit 703 are formed on the substrate. There is a case where the signal line side driver circuit 702 is integrally formed therewith and mounted as a separate driver IC, and as shown in FIG. 16C, the pixel portion 701, the signal line side driver circuit 702, and the scanning line side driver circuit 703 May be integrally formed on the substrate, but any form may be used.

  As other external circuit configurations, on the input side of the video signal, a video signal amplification circuit 705 that amplifies the video signal, and a video that converts the signal output therefrom to a color signal corresponding to each color of red, green, and blue It comprises a signal processing circuit 706 and a control circuit 707 for converting the video signal into the input specifications of the driver IC. The control circuit 707 outputs signals to the scanning line side and the signal line side, respectively. In the case of digital driving, a signal dividing circuit 708 may be provided on the signal line side and an input digital signal may be divided into m pieces and supplied.

  Of the signals received by the tuner 704, the audio signal is sent to the audio signal amplification circuit 709, and the output is supplied to the speaker 713 through the audio signal processing circuit 710. The control circuit 711 receives the receiving station (reception frequency) and volume control information from the input unit 712, and sends a signal to the tuner 704 and the audio signal processing circuit 710.

  As shown in FIGS. 21A, 21B, and 21C, a liquid crystal display module manufactured in Embodiment Mode 9 can be incorporated into a housing to complete a television device. When a liquid crystal display module as shown in FIGS. 18A and 18B is used, a liquid crystal television device can be completed. In addition, when a display device having a three-dimensional display function as in Embodiment 10 is used, a television device capable of performing three-dimensional display can be manufactured. In FIG. 21A, 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 structure, 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 can be manufactured with low power consumption. You may form with the liquid crystal display panel which can be displayed. 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. In that case, when the present invention is used for a liquid crystal display panel, a highly reliable display device can be obtained even when such a large substrate is used and many TFTs and electronic components are used.

  FIG. 21B illustrates a television device having a large display portion of 20 to 80 inches, for example, which includes a housing 2010, a keyboard portion 2012 that is an operation portion, a display portion 2011, a speaker portion 2013, and the like. The present invention is applied to manufacture of the display portion 2011. The display portion in FIG. 21B is a television device having a curved display portion because a bendable substance is used. Since the shape of the display portion can be freely designed as described above, a television device having a desired shape can be manufactured.

  FIG. 21C illustrates a television device having a large display portion of 20 to 80 inches, for example, which includes a housing 2030, a display portion 2031, a remote control device 2032 that is an operation portion, a speaker portion 2033, and the like. The present invention is applied to manufacturing the display portion 2031. The television device in FIG. 21C is a wall-hanging type and does not require a large installation space.

  Further, since the birefringence of the liquid crystal changes depending on the temperature, the polarization state of the light passing through the liquid crystal changes, and the light leakage from the viewing side polarizer changes. As a result, the contrast ratio varies depending on the temperature of the liquid crystal. Therefore, it is desirable to control the drive voltage so as to maintain a constant contrast ratio. In order to control the driving voltage, an element for detecting the transmittance may be arranged in the display device, and the driving voltage may be controlled based on the detection result. As an element for detecting the transmittance, a photosensor composed of an IC chip can be used.

  In the display device, an element for detecting temperature may be arranged, and the drive voltage may be controlled based on the detection result and the change in contrast ratio with respect to the temperature of the liquid crystal element. As an element for detecting the temperature, a temperature sensor composed of an IC chip can be used. At this time, the element for detecting the transmittance and the element for detecting the temperature are preferably arranged so as to be hidden in the housing portion of the display device.

  For example, an element for detecting the temperature is arranged near the liquid crystal display element of the display device of the present invention mounted on the television apparatus shown in FIGS. 21A to 21C, and information on the temperature change of the liquid crystal is used to control the drive voltage. It is only necessary to feed back to the circuit. Since the element for detecting the transmittance is preferably closer to the viewing side, it may be disposed on the surface of the display screen and covered with the housing. Then, the detected change in transmittance may be fed back to the circuit for controlling the drive voltage, similarly to the temperature.

  In the present invention, since the transmission axes of the polarizers of the pair of layers including the polarizers to be stacked are crossed Nicols having a deviation, the fine contrast ratio can be adjusted, so that the temperature of the liquid crystal It is possible to cope with a slight difference in contrast ratio with respect to the above, and to obtain an optimum contrast ratio. Therefore, a pair of layers including polarizers stacked in parallel Nicols are provided in order to obtain an optimal contrast ratio depending on the conditions (indoor, outdoor, climate, etc.) in which the display device of the present invention is used. It is possible to provide a television device and an electronic device which are manufactured so that the transmission axes of the polarizers of the respective layers are crossed Nicols having a predetermined shift, and display with high performance and high image quality.

  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.

(Embodiment 12)
As an electronic apparatus according to the present invention, a television device (also simply referred to as a television or a television receiver), a camera such as a digital camera or a digital video camera, a mobile phone device (also simply referred to as a mobile phone or a mobile phone), a PDA, or the like Portable information terminals, portable game machines, computer monitors, computers, sound reproduction apparatuses such as car audio, and image reproduction apparatuses equipped with recording media such as home game machines. A specific example will be described with reference to FIG.

A portable information terminal device illustrated in FIG. 22A 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 portable information terminal device with a high contrast ratio can be provided.
A digital video camera shown in FIG. 22B 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 digital video camera with a high contrast ratio can be provided.
A cellular phone shown in FIG. 22C 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 mobile phone with a high contrast ratio can be provided.

  A portable television device shown in FIG. 22D 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 portable television device with a high contrast ratio 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. 22E 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 portable computer with a high contrast ratio can be provided.
As described above, the display device of the present invention can provide an electronic device with a high contrast ratio.

In this embodiment, when a TN mode transmissive liquid crystal display device is assumed, polarizers are stacked, and the backlight side polarizer and the viewer side polarizer are arranged in crossed Nicols with a deviation. The results will be described. For comparison, optical calculations were also performed for the case where no polarizer was stacked.
The contrast ratio was the ratio of white transmittance to black transmittance (white transmittance / black transmittance), and the black transmittance and white transmittance were calculated to calculate the contrast ratio.

The calculation in the present embodiment uses an optical calculation simulator LCD MASTER (manufactured by Shintech Co., Ltd.) for liquid crystal. When calculating the transmittance with the LCD MASTER, the calculation was performed with a 2 × 2 matrix optical calculation algorithm that does not consider multiple interference between elements, and the setting wavelength was 550 nm.
As shown in FIG. 25, the optical arrangement of the optical calculation is as follows: polarizer 2, retardation film B 2, retardation film A 2, glass substrate, TN liquid crystal, retardation film A 1, retardation film B 1, polarization In this structure, the child 1 is laminated.

  In this embodiment, two retardation films (a retardation film A1, a retardation film B1, a retardation film A2, and a retardation film B2) are arranged one above the other for the purpose of wide viewing angle in the TN mode. First, in order to obtain the transmission axis angle of the viewing-side polarizer 1 with the highest contrast ratio, the number of viewing-side polarizers 1 is one, and the angle of the transmission axis of the viewing-side polarizer 1 is the backlight-side polarizer. The contrast ratio (0V) of 0V (white) transmittance and 5V (black) transmittance when the voltage applied to the liquid crystal is 0V and 5V by rotating within a range of plus or minus 1 degree from the crossed Nicols with respect to the transmission axis of 2 Transmittance / 5V transmittance) was calculated. The transmittance is the transmittance in front of the display element with respect to the backlight when the backlight is 1.

  The physical property values of the polarizer 1 and the polarizer 2 at a wavelength of 550 nm are shown in Table 1, the physical property values and arrangement of the liquid crystal at a wavelength of 550 nm are shown in Table 2, and the physical property values and the arrangement of the retardation film A1 and the retardation film A2 at a wavelength of 550 nm are shown. Table 3 shows physical property values and arrangement of the retardation film B1 and the retardation film B2 at a wavelength of 550 nm, respectively. The retardation films A1, A2, B1, and B2 are all retardation films having negative uniaxiality.

The results of contrast ratio, black transmittance, and white transmittance when the viewing-side polarizer is rotated are shown in FIGS. 26, 27, and 28, respectively.
From FIG. 26, it can be seen that when the angle of the transmission axis of the viewing side polarizer is 134.9 degrees, the contrast ratio is the highest and is shifted by 0.1 degrees from 135 degrees which is crossed Nicol. From FIG. 27, the white transmittance does not show the maximum value in this rotation range, and the angle at which the black transmittance is lowest as compared with FIG. 28 is 134.9 degrees, so that the viewing side polarizer with the highest contrast ratio is obtained. The angle of the transmission axis of 1 is the angle at which the black transmittance is lowest. That is, high contrast can be achieved by shifting the transmission axis of the polarizer 1 at an angle at which the black transmittance is lowest.

Subsequently, the contrast ratios according to the number of polarizers were compared. The structure A in FIG. 29A has two polarizers, and in order from the backlight, the polarizer 2, the retardation film B2, the retardation film A2, the glass substrate, the TN liquid crystal, the retardation film A1, and the retardation film. The viewing side polarizer 1 is arranged at 134.9 degrees, the transmission axis of which is shifted from the transmission axis of the backlight side polarizer 2 and crossed Nicols.
In the structure B of FIG. 29B, the number of polarizers is 3, and the polarizer 3, the polarizer 2, the retardation film B2, the retardation film A2, the glass substrate, the TN liquid crystal, and the retardation film are sequentially arranged from the backlight. The viewing-side polarizer 1 is arranged at 134.9 degrees with its transmission axis deviating from the transmission axis of the backlight-side polarizer 2 and crossed Nicols. Yes. Of course, the transmission axes of the polarizer 2 and the polarizer 3 are parallel Nicols.

In the structure C of FIG. 29C, the number of polarizers is four, and in order from the backlight, the polarizer 3, the polarizer 2, the retardation film B2, the retardation film A2, the glass substrate, the TN liquid crystal, and the retardation film. A1, a retardation film B1, a polarizer 1, and a polarizer 4 are laminated. The viewing side polarizer 1 has a transmission axis deviated from the transmission axis of the backlight side polarizer 2 and crossed Nicols at 134.9 degrees. It is arranged. Of course, the transmission axes of the polarizer 2 and the polarizer 3 and the transmission axes of the polarizer 1 and the polarizer 4 are parallel Nicols.
The polarizer 3 and the polarizer 4 have the same physical property values as the polarizer 1 and the polarizer 2, and the physical property values of the polarizers 1 to 4, the physical properties of the liquid crystals, the retardation films A1, A2, B1, and B2, and the arrangement thereof are listed. 1, Table 2, Table 3, and Table 4.

Table 5 shows the results of the contrast ratio of 0 V (white) transmittance and 5 V (black) transmittance in front of the display elements of the structures A, B, and C at a wavelength of 550 nm. The structure C in which a pair of layers in which polarizers are stacked is formed and the pair of layers is arranged in crossed Nicols with the transmission axis of the polarizer shifted is compared to the structure A in which the polarizer single layer is arranged in crossed Nicols. It can be seen that the contrast ratio is four times higher.
From the above results, it is possible to obtain a high contrast ratio by laminating a plurality of polarizers and arranging the backlight-side polarizer and the viewing-side polarizer in a crossed Nicol having a shift.

  In this embodiment, when a VA mode transmissive liquid crystal display device is assumed, polarizers are stacked, and the backlight side polarizer and the viewer side polarizer are arranged in crossed Nicols with a shift. The results will be described. For comparison, optical calculations were also performed for the case where no polarizer was stacked. The contrast ratio was the ratio of white transmittance to black transmittance (white transmittance / black transmittance), and the black transmittance and white transmittance were calculated to calculate the contrast ratio.

The calculation in this example uses an optical calculation simulator LCD MASTER (manufactured by Shintech Co., Ltd.) for liquid crystal. When calculating the transmittance with the LCD MASTER, the calculation was performed with a 2 × 2 matrix optical calculation algorithm that does not consider multiple interference between elements, and the setting wavelength was 550 nm.
As shown in FIG. 30, the optical arrangement of the optical calculation has a structure in which a polarizer 2, a retardation film C2, a glass substrate, a VA liquid crystal, a retardation film C1, and a polarizer 1 are laminated in order from the backlight.

  In the present embodiment, one retardation film (retardation film C1 and retardation film C2) is arranged one above the other for the purpose of wide viewing angle in the VA mode. First, in order to obtain the transmission axis angle of the viewing-side polarizer 1 with the highest contrast ratio, the number of viewing-side polarizers 1 is one, and the angle of the transmission axis of the viewing-side polarizer 1 is the backlight-side polarizer. The contrast ratio of 7V (white) transmittance and 0V (black) transmittance when the voltage applied to the liquid crystal is 0V and 7V by rotating within the range of plus or minus 1 degree from crossed Nicols with respect to the transmission axis of 2 (7V Transmittance / 0V transmittance) was calculated. The transmittance is the transmittance in front of the display element with respect to the backlight when the backlight is 1.

  Table 6 shows physical property values of polarizer 1 and polarizer 2 at a wavelength of 550 nm, Table 7 shows physical property values and arrangement of liquid crystal at a wavelength of 550 nm, and physical property values and arrangement of retardation film C1 and retardation film C2 at a wavelength of 550 nm. Each is shown in Table 8. The retardation films C1 and C2 are both retardation films having negative uniaxiality.

The results of contrast ratio, white transmittance, and black transmittance when the viewing-side polarizer is rotated are shown in FIGS. 31, 32, and 33, respectively.
It can be seen from FIG. 31 that when the angle of the transmission axis of the viewing side polarizer is 45.1 degrees, the contrast ratio is the highest and is shifted by 0.1 degrees from 45 degrees that is crossed Nicol. From FIG. 32, the white transmittance does not show the maximum value in this rotation range, and the angle at which the black transmittance becomes the lowest in FIG. 33 is 45.1 degrees, so that the viewing side polarizer with the highest contrast ratio is obtained. The angle of the transmission axis of 1 is the angle at which the black transmittance is lowest. That is, high contrast can be achieved by shifting the transmission axis of the polarizer 1 to an angle at which the black transmittance is lowest.

  Subsequently, the contrast ratios according to the number of polarizers were compared. The structure D in FIG. 34A is a structure in which the number of polarizers is one, and the polarizer 2, the retardation film C2, the glass substrate, the VA liquid crystal, the retardation film C1, and the polarizer 1 are stacked in this order from the backlight side. The viewing-side polarizer 1 is arranged at 45.1 degrees with its transmission axis deviating from the transmission axis of the backlight-side polarizer 2 from crossed Nicols. In the structure E of FIG. 34B, the number of polarizers is three, and the polarizer 3, the polarizer 2, the retardation film C2, the glass substrate, the VA liquid crystal, the retardation film C1, and the polarizer 1 are sequentially arranged from the backlight side. The viewing-side polarizer 1 is arranged at 45.1 degrees with its transmission axis deviating from the transmission axis of the backlight-side polarizer 2 from crossed Nicols. Of course, the transmission axes of the polarizer 2 and the polarizer 3 are parallel Nicols.

The structure F in FIG. 34C has four polarizers, and in order from the backlight side, the polarizer 3, the polarizer 2, the retardation film C2, the glass substrate, the VA liquid crystal, the retardation film C1, and the polarizer 1 The viewing-side polarizer 1 is arranged at 45.1 degrees with its transmission axis deviating from the transmission axis of the backlight-side polarizer 2 and crossed Nicols. Of course, the transmission axes of the polarizer 2 and the polarizer 3 and the transmission axes of the polarizer 1 and the polarizer 4 are parallel Nicols.
The polarizer 3 and the polarizer 4 have the same physical property values as the polarizer 1 and the polarizer 2, and the physical property values of the polarizers 1 to 4, and the physical property values and arrangement of the liquid crystals and the retardation films C1 and C2 are shown in Table 6. Same as Tables 7 and 8.

Table 9 shows the results of the contrast ratio between the 7V transmittance and the 0V transmittance in the front of the display elements of the structures D, E, and F at a wavelength of 550 nm. It can be seen that the structure F in which the polarizers are stacked and shifted from the crossed Nicols has a contrast ratio that is 50 times higher than the structure D in which the polarizer single layers are arranged in the crossed Nicols.
From the above results, the polarizer layers laminated with parallel Nicols were arranged on the outside of both the backlight side and the viewing side glass substrates, respectively, and arranged on the viewing side and the polarizer arranged on the backlight side. It can be seen that a high contrast ratio can be obtained by arranging the polarizers in crossed Nicols with a shift.

It is sectional drawing and the perspective view which showed the display apparatus of this invention. It is sectional drawing and the perspective view which showed the display apparatus of this invention. It is sectional drawing and the perspective view which showed the display apparatus of this invention. It is sectional drawing and the perspective view which showed the display apparatus of this invention. It is the figure which showed the display apparatus of this invention. It is the figure 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 which showed the display apparatus of this invention. It is the top view which showed the display apparatus of this invention. It is sectional drawing which showed the liquid crystal mode of this invention. It is sectional drawing which showed the liquid crystal mode of this invention. It is sectional drawing which showed the liquid crystal mode of this invention. It is sectional drawing which showed the structure of the layer containing the polarizer 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 the top view 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 irradiation means which the display apparatus of this invention has. 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 display apparatus of this invention. It is the block diagram which showed the display apparatus of this invention. It is the figure which showed the experimental condition of this invention. It is the graph which showed the experimental result of this invention. It is the graph which showed the experimental result of this invention. It is the graph which showed the experimental result of this invention. It is the figure which showed the experimental condition of this invention. It is the figure which showed the experimental condition of this invention. It is the graph which showed the experimental result of this invention. It is the graph which showed the experimental result of this invention. It is the graph which showed the experimental result of this invention. It is the figure which showed the experimental condition of this invention.

Claims (12)

A first light-transmitting substrate and a second light-transmitting substrate which are arranged to face each other;
A display element sandwiched between the first translucent substrate and the second translucent substrate;
A first layer including a plurality of polarizers stacked on the outside of the first translucent substrate;
A second layer including a plurality of polarizers stacked on the outside of the second translucent substrate,
The first layer and the second layer are arranged so that the transmission axes of the polarizers to be stacked are parallel Nicols,
The display device, wherein the polarizer of the first layer and the polarizer of the second layer are arranged in crossed Nicols where the transmission axes of the first layer and the second layer of the polarizer are shifted. A first light-transmitting substrate and a second light-transmitting substrate which are arranged to face each other;
A display element sandwiched between the first translucent substrate and the second translucent substrate;
A first layer including a plurality of polarizers stacked on the outside of the first translucent substrate;
A second layer including a plurality of polarizers stacked on the outside of the second translucent substrate;
A first retardation film between the first translucent substrate and the first layer;
A second retardation film between the second translucent substrate and the second layer;
The first layer and the second layer are arranged so that the transmission axes of the polarizers to be stacked are parallel Nicols,
The display device, wherein the polarizer of the first layer and the polarizer of the second layer are arranged in crossed Nicols where the transmission axes of the first layer and the second layer of the polarizer are shifted.   3. The display device according to claim 1, wherein the first layer and the second layer are each provided between a pair of protective layers. In claim 1 or claim 2,
The first layer is a stack of a 1A polarizer and a 1B polarizer,
The second layer is a laminate of a 2A polarizer and a 2B polarizer,
All the polarizers of the said 1A polarizer, 1B polarizer, 2A polarizer, and 2B polarizer are provided between protective layers, The display apparatus characterized by the above-mentioned. In claim 1 or claim 2,
The first layer is a stack of a 1A polarizer and a 1B polarizer,
The second layer is a laminate of a 2A polarizer and a 2B polarizer,
All the polarizers of the 1A polarizer, the 1B polarizer, the 2A polarizer, and the 2B polarizer are provided between a pair of protective layers, respectively. A first light-transmitting substrate and a second light-transmitting substrate which are arranged to face each other;
A display element sandwiched between the first translucent substrate and the second translucent substrate;
A first layer including a plurality of polarizers stacked on the outside of the first translucent substrate;
A second layer including a plurality of polarizers stacked on the outside of the second translucent substrate,
The first layer is laminated in the order of a first A polarizer, a first B polarizer, and a first C polarizer from the first light transmitting substrate side.
The first layer and the second layer are arranged so that the transmission axes of the polarizers to be stacked are parallel Nicols,
The display device, wherein the polarizer of the first layer and the polarizer of the second layer are arranged in crossed Nicols where the transmission axes of the first layer and the second layer of the polarizer are shifted. A first light-transmitting substrate and a second light-transmitting substrate which are arranged to face each other;
A display element sandwiched between the first translucent substrate and the second translucent substrate;
A first layer including a plurality of polarizers stacked on the outside of the first translucent substrate;
A second layer including a plurality of polarizers stacked on the outside of the second translucent substrate;
A first retardation film between the first translucent substrate and the first layer;
A second retardation film between the second translucent substrate and the second layer;
The first layer is laminated in the order of a first A polarizer, a first B polarizer, and a first C polarizer from the first light transmitting substrate side.
The first layer and the second layer are arranged so that the transmission axes of the polarizers to be stacked are parallel Nicols,
The display device, wherein the polarizer of the first layer and the polarizer of the second layer are arranged in crossed Nicols where the transmission axes of the first layer and the second layer of the polarizer are shifted.   8. The display device according to claim 6, wherein the first layer and the second layer are each provided between a pair of protective layers. In claim 6 or claim 7,
The second layer is a laminate of a 2A polarizer and a 2B polarizer,
All of the polarizers of the 1A polarizer, the 1B polarizer, the 1C polarizer, the 2A polarizer, and the 2B polarizer are provided between protective layers. apparatus. In claim 6 or claim 7,
The second layer is a laminate of a 2A polarizer and a 2B polarizer,
All the polarizers of the 1A polarizer, the 1B polarizer, the 1C polarizer, the 2A polarizer, and the 2B polarizer are provided between a pair of protective layers, respectively. Display device.   The display device according to claim 1, further comprising a light source outside the second layer.   12. The display device according to claim 1, wherein the display element is a liquid crystal element.

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