KR101117751B1 - Contrast ratio improvement film for display device and OLED having the same - Google Patents

Abstract

The present invention relates to a light and shade enhancement film for a display device and an organic electroluminescent device using the same, more specifically, a substrate made of a polymer resin material; And the substrate is mixed with a light absorbing dye, and an organic field including a light and shade enhancement film and a light and shade enhancement film for a display device, characterized in that the AR film or projection type antireflection film is laminated on the outer surface of the substrate. A light emitting device.

Description

Brightness contrast film for display devices and organic light emitting device using the same {Contrast ratio improvement film for display device and OLED having the same}

The present invention relates to a clear light and shade enhancement film for a display device and an organic light emitting device using the same, and more particularly to a clear light contrast enhancement film for a display device to improve the clear contrast and to improve the image quality and an organic light emitting device using the same It is about.

As the modern society is highly developed, optoelectronic-related parts and devices are remarkably advanced and distributed. Among them, display apparatuses for displaying images are widely used in mobile screens, television monitors, and monitors of personal computers, and the size of such displays is increasing at the same time.

Among such display devices, representative examples of self-luminous display devices include organic light emitting diodes (OLEDs) and plasma display panels (PDPs). Such a self-luminous display device can implement a display through self-emission of the light emitting material.

Among them, in the organic light emitting device, the organic light emitting unit generally injects electrons and holes into the light emitting layer from the electron injection electrode and the hole injection electrode, respectively. The light emitting device is a device that emits light when an exciton, which is a combination of injected electrons and holes, drops from an excited state to a ground state.

Due to this principle, unlike the conventional thin film liquid crystal display device, since a separate light source is not required, there is an advantage in that the volume and weight of the device can be reduced.

In addition, the organic EL device exhibits high quality panel characteristics (low power, high brightness, high reaction rate, low weight). OELD is considered to be a powerful next-generation display that can be applied to portable communication products such as mobile communication terminal, CNS (Car Navigation System), personal digital assistances (PDA), Palm PC, etc.

In general, the organic light emitting device is composed of a transparent support substrate and a sealing substrate spaced apart from each other, the support substrate and the sealing substrate is encapsulated with each other by a sealing material (encapsulation). An array portion including a plurality of thin film transistors, gates, data lines, and storage capacitors is formed on an upper portion of the support substrate. have. In this case, the organic layer expresses the colors of red (R), green (G), and blue (B), and in general, red (R), green (G), and blue (B) colors for each pixel. A separate organic material emitting light is used as a pattern.

Since the organic light emitting device (OLED) is a self-luminous type, the viewing angle is wider than the LCD, the contrast is good, and since the backlight is not required, the organic light emitting device (OLED) can be reduced in weight and advantageous in terms of power consumption. In addition, it is easy to display video because it has a sensitive screen and quick response time compared to other displays, and unlike LCD, it is attracting attention as a next-generation display because it is composed of solid thin film, which is strong in vibration and has a relatively wide use temperature range.

In the self-luminous display device, various methods have been sought to have a clear image quality, but the clear contrast ratio is an important factor in order to have a clear image quality. Contrast Ratio can be defined as "(brightness of white light + brightness of reflected light) ÷ (brightness of black light + brightness of reflected light), and the higher the clear contrast ratio, the clearer the image quality. The electrode layer of the light emitting part becomes visible, and thus a problem of poor image quality occurs.

Conventionally, the organic light emitting device has included a λ / 4 film and a polarizing film on the display substrate visible to increase the contrast ratio. In this case, the clear contrast ratio is high, but there is an advantage of having a clear image quality. However, since the λ / 4 film and the polarizing film are expensive, the transmittance is excessively suppressed due to the problem of high production cost and the polarizing film. Problems due to unnecessary polarization of light, such as the luminance is changed to cause a non-uniformity of the image quality.

Korean Patent Laid-Open Publication No. 2008-0049295 relates to an organic electroluminescent display device, comprising: a first transparent substrate, at least one organic light emitting element formed on the first transparent substrate and corresponding to an organic light emitting cell, respectively, and on the organic light emitting element An organic light emitting display device comprising: a second transparent substrate formed on a surface of the second transparent substrate, wherein a plurality of external light shielding portions and a plurality of light focusing portions are formed between the adjacent external light shielding portions; In this regard, the patent introduces an organic light emitting display device capable of maintaining contrast while minimizing light loss. However, the above-mentioned patent has an advantage of improving the contrast ratio, but there is a problem of causing excessive decrease in transmittance.

Accordingly, in order to solve the above problems, it has been desired to develop a film for a display device and a organic electroluminescent device using the same, which improves the contrast ratio and improves transmittance and does not cause polarization.

In order to solve the above problems, an object of the present invention is to reduce the production cost by using a polarizing film, to improve the brightness from the display device, and to improve the brightness and contrast ratio, and a display device film that can implement a three-dimensional screen and using the same An organic electroluminescent device is provided.

Another object of the present invention is to provide a film that improves transmittance and does not cause polarization and an organic light emitting device using the same.

It is still another object of the present invention to provide a film for a display device displaying a high picture quality with improved contrast ratio and an organic light emitting device using the same.

In order to achieve the above object, the present invention is a substrate of a polymer resin material; And the base material is mixed with the light absorption dye, and provides a clear light and dark enhancement film for a display device, characterized in that the AR film or projection-type antireflection film is laminated on the outer surface of the substrate.

In another aspect, the present invention provides a light and shade enhancement film for a display device, characterized in that the thickness (T) of the projection structure in the projection anti-reflective film is 10 to 500 nm.

In another aspect, the present invention provides a light and shade enhancement film for a display device, characterized in that the ratio of the thickness (T) and height (H) of the projection structure in the projection anti-reflective film is 1: 0.5 to 1: 3.

In another aspect, the present invention provides a light and shade enhancement film for a display device, characterized in that the pitch of the projection structure in the projection antireflection film is 100 to 400 nm.

In another aspect, the present invention provides a clear light and dark enhancement film for a display device, characterized in that hard coating or antifouling coating is additionally included on the outer surface of the AR film or projection antireflective film.

In addition, the present invention is the light and shade enhancement film is utilized in the organic EL device, the organic EL device, the support substrate; An organic light emitting unit formed on one surface of the support substrate and including an organic light emitting layer between a pair of electrodes; An encapsulation substrate positioned above the organic light emitting part; And an encapsulant for coupling the support substrate and the encapsulation substrate, wherein the encapsulation substrate is formed of the clear light and dark enhancement film.

In another aspect, the present invention provides an organic electroluminescent device characterized in that the hard coating or antifouling coating is additionally included in the outermost surface of the sealing substrate.

In another aspect, the present invention provides an organic electroluminescent device further comprising a planarization layer functioning as a buffer layer between the upper surface of the support substrate and the lower surface of the organic electroluminescent unit.

In another aspect, the present invention provides an organic electroluminescent device characterized in that the interior space partitioned by the support substrate and the sealing substrate is filled with one of an inert gas of nitrogen, neon or argon.

In another aspect, the present invention provides an organic electroluminescent device, characterized in that the organic electroluminescent unit is stacked between the electrode layer and the electrode layer, a hole injection layer, a hole transport layer, an organic light emitting layer, an electron transport layer, an electron injection layer in order.

The clear light and dark enhancement film for a display device and the organic light emitting device using the same according to the present invention can realize a viewing angle characteristic suitable for luminance improvement and three-dimensional screen configuration with reduced production cost by using a polarizing film.

In addition, the clear light and dark enhancement film for a display device and the organic light emitting device using the same according to the present invention has the effect of improving the transmittance and does not cause polarization.

In addition, the clear light and dark enhancement film for a display device and the organic light emitting device using the same according to the present invention has the effect of displaying a high picture quality of the light contrast ratio is improved.

Figure 1 shows a cross-sectional view of the clear and light contrast enhancement film for a display device according to an embodiment of the present invention.
2 and 3 show a schematic cross-sectional view and a perspective view of the projection antireflective film.
4 is a cross-sectional view of an organic light emitting display device according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. First, it should be noted that, in the drawings, the same components or parts have the same reference numerals as much as possible. In describing the present invention, detailed descriptions of related well-known functions or configurations are omitted in order not to obscure the subject matter of the present invention.

The terms " about ", " substantially ", etc. used to the extent that they are used herein are intended to be taken to mean an approximation to or in the numerical value of the manufacturing and material tolerances inherent in the meanings mentioned, Accurate or absolute numbers are used to help prevent unauthorized exploitation by unauthorized intruders of the referenced disclosure.

As used herein, "AR film" refers to an anti-reflection film (Anti-Reflection) reflectance by the interference effect using a change in the wavelength and intensity of light according to the refractive index and thickness of the medium in the incident light, transmitted light, and reflected light It means a film made in the manner of lowering.

The present invention is a substrate of a polymer resin material; And the substrate is a light-absorbing dye is mixed, and on the outer surface of the substrate relates to a clear light and dark enhancement film for display device, characterized in that the laminated projection-type antireflection film.

The substrate refers to a base film (base film) used in the film for the display device by mixing a light absorption dye therein to maximize the transmittance of the display light, and to improve the viewing angle and prevent the generation of moiré.

In describing the present invention, an organic electroluminescent device is described as an example, but the present invention is not limited thereto, and the present invention may be applied to the self-luminous display device.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Figure 1 shows a cross-sectional view of the brightness contrast contrast enhancement film for a display device according to an embodiment of the present invention, Figures 2 and 3 shows a schematic cross-sectional view and a perspective view of the projection antireflective film.

The light and shade enhancement film according to the present invention is characterized in that the light absorbing dye is mixed on the substrate of the display device, and the AR film or the projection-type antireflection film shown at 110 is laminated on the outer surface of the substrate 120.

The AR film refers to a film made of a method of lowering reflectance by an interference effect by using a change in wavelength and intensity of light according to refractive index and thickness of a medium in incident light, transmitted light, and reflected light, wherein the AR having an antireflection function The film generally has a multi-layer structure, and an example of the anti-reflection layer having a multi-layer structure includes a two-layer structure consisting of a high refractive index layer and a low refractive index layer, a middle refractive index layer, a high refractive index layer, and a low refractive index layer from the base material layer below. For example, a four-layer structure composed of a layer structure, a high refractive index layer, a low refractive index layer, a high refractive index layer, and a low refractive index layer is arranged in order.

The AR film is polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polycarbonate (PC), polyethylene sulfone (PES), transparent polyimide (PI), polyarylate (PAR), polycyclic olefin ( High transparency materials, such as PCO), are used.

Optionally, the projection-type antireflection film 110a may be laminated on the outer surface of the substrate 120 instead of the AR film, and the surface of the projection anti-reflection film 110a has a fine projection structure. The thickness T of the projections has a regular projection arrangement in which a thick portion of the projections has a size of 10 to 500 nm, and the pitch of the projections is preferably 100 to 400 nm. In addition, the ratio of the thickness T and the height H of the projection is preferably about 1: 0.5 to 1: 3 ratio. The film having the protrusion structure has a feature of hardly reflecting light because the refractive index continuously changes in the thickness direction of the film.

The projection antireflective film 110a has a reflectance of 1% or less, which shows excellent performance of 1/5 or less as compared with a general antireflection film.

In addition, the fine projection structure in the projection type antireflection film 110a is excellent in water repellent effect is characterized in that the water is not absorbed well even when exposed to water.

In addition, the refractive index of the projection-type antireflective film is preferably smaller than that of the film of the base material so that external light is not reflected by the film.

The AR film and the projection type antireflection film 110a may prevent the external light incident from the viewer's direction from being reflected back to the outside, thereby improving the contrast ratio of the display.

On the other hand, the substrate 120 includes a light absorbing dye, the light absorbing dye is mixed with the substrate 120 has the advantage that the transmittance is improved compared to the polarizing film attached to improve the existing contrast ratio.

The substrate 120 used in the present invention preferably uses a polymer resin material. The polymer resin may be a transparent polymer resin. For example, polyethylene naphthalate (PEN), polyethylene terephthalate (PET), or polycarbonate ( PC), polyethylene sulfone (PES), transparent polyimide (PI), polyarylate (PAR), polycyclic olefin (PCO), crosslinked epoxy, crosslinked urethane film, and the like, but are not limited thereto.

As a light absorption dye used for this invention, it is a well-known organic pigment or dye, and can be used individually by 1 type or in mixture of 2 or more types. Although the compounding quantity of dye depends on the absorbance according to the kind, it determines and mix | blends so that the transmittance | permeability of resin mix | blended and film-formed will be 50-80% level normally.

Below, the specific example of the organic pigment or dye which can be used by the light absorption dye of this invention is shown by a color index number.

Red colored pigments or dyes for forming red filter segments include, for example, CI Pigment Red 7, 9, 14, 41, 48: 1, 48: 2, 48: 3, 48: 4, 81: 1, 81: 2, 81: 3, 97, 122, 123, 146, 149, 168, 177, 178, 180, 184, 185, 187, 192, 200, 202, 208, 210, 215, 216, 217, 220, 223, Red pigments such as 224, 226, 227, 228, 240, 246, 254, 255, 264, 272 can be used, and yellow and orange pigments or dyes can be used in combination.

As yellow pigments or dyes for forming yellow filter segments, for example, C.I. Pigment Yellow 1, 2, 3, 4, 5, 6, 10, 12, 13, 14, 15, 16, 17, 18, 20, 24, 31, 32, 34, 35, 35: 1, 36, 36: 1, 37, 37: 1, 40, 42, 43, 53, 55, 60, 61, 62, 63, 65, 73, 74, 77, 81, 83, 86, 93, 94, 95, 97, 98, 100, 101, 104, 106, 108, 109, 210, 113, 114, 115, 116, 117, 118, 119, 120, 123, 125, 126, 127, 128, 129, 137, 138, 139, 147, 148, 150, 151, 152, 153, 154, 155, 156, 161, 162, 164, 166, 167, 168, 169, 240, 171, 172, 173, 174, 175, 176, 177, 179, 180, Yellow pigments or dyes such as 181, 182, 185, 187, 188, 193, 194, and 199 can be used.

Orange pigments or dyes for forming orange filter segments are described, for example, in C.I. Pigment orange Orange pigments or dyes such as 36, 43, 51, 55, 59 and 61 can be used.

As the green pigment or dye for forming the green filter segment, for example, C.I. Green pigments or dyes such as Pigment Green 7, 10, 36, 37 can be used.

As a blue pigment or dye for forming a blue filter segment, it is C.I. Pigment Blue 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, 16, 22, 60, 64 or the like can be used a blue pigment or dye. Blue pigments or dyes include C.I. Pigment Violet 1, 19, 23, 27, 29, 30, 32, 37, 40, 42, 50, such as purple pigments or dyes can be used in combination.

Magenta pigments or dyes for forming magenta filter segments include, for example, C.I. Purple and red pigments or dyes such as Pigment Violet 1, 19, C.I Pigment Red 144, 146, 177, 169, 81 and the like can be used. A magenta pigment can be used in combination with a yellow pigment.

In addition, black pigments or dyes such as carbon black having a particle diameter of 200 nm or less can be used.

The dye used for this invention can be contained in a film in the range which does not reduce heat resistance.

In addition, in order to protect the AR film or the projection type antireflection film may be additionally coated on the outer surface, for example, a functional layer such as hard coating, antifouling coating may be additionally included. In addition, the refractive index of the coating is preferably smaller than the refractive index of the projection antireflection film or AR film.

The clear and dark contrast enhancing film according to the present invention serves to improve the clear and dark contrast ratio, the contrast ratio (Contrast Ratio) is to be defined as "(luminance of white light + luminance of reflected light) ÷ (luminance of black light + luminance of reflected light). The greater the contrast ratio, the higher the display device.

Two related variables that the clear contrast ratio is improved can be improved due to the decrease in the reflectance and the increase in the transmittance, the film according to the present invention is improved in the transmittance, and the external light shielding is performed to reduce the reflectance so that the clear contrast ratio It can be seen that the image quality is improved.

4 is a cross-sectional view of an organic light emitting display device according to an embodiment of the present invention.

According to FIG. 4, the present invention provides an organic light emitting device that emits light toward a sealing substrate, and includes a support substrate 210, an organic light emitting unit 220 formed on one surface of the support substrate, that is, a support substrate, and the organic light emitting unit. A sealing substrate is disposed on the supporting substrate 210 so as to block from the sealing substrate, and the sealing substrate is formed of the above-mentioned light and shade enhancement film 100.

Conventional organic light emitting devices have been difficult to be used directly in various display devices in which high quality is an important factor due to the visible problem of the electrode layer of the organic light emitting part. Accordingly, the λ / 4 film and the polarizing film on the outer surface of the sealing substrate. By bonding to improve the visibility to provide a high-quality organic electroluminescent device. However, although there is an advantage of high quality, the transmittance is excessively suppressed due to the polarizing film, the brightness is changed by the viewing angle when implementing the 3D display, there is a problem causing the non-uniformity of the image quality.

Therefore, the present invention has the advantage that the sealing substrate is composed of the light and dark enhancement film 100 to improve the transmittance of the display light and at the same time does not unnecessarily polarize the display light.

In addition, the outer surface, that is, the outermost surface of the sealing substrate may be additionally coated in order to protect the AR film or the projection type anti-reflective film, for example, hard coating, antifouling coating, etc. may further include a functional layer. have. In addition, the refractive index of the coating is preferably smaller than the refractive index of the projection antireflection film or AR film.

Meanwhile, the planarization layer 230 functioning as a buffer layer may be formed on the upper surface of the support substrate 210 according to an embodiment of the present invention. The planarization layer 230 may be obtained by partially hydrolyzing the composition for forming an organic or organic-inorganic hybrid layer to form a sol solution, and then coating and curing it on the support substrate 210 which is a transparent substrate. The coating method may be a method such as spin coating, roll coating, bar coating, dip coating, gravure coating, spray coating. The sol state curing method may be used, such as thermal curing, UV curing, infrared curing, high frequency heat treatment. The thickness after the flattening layer is cured is 0.1 µm to 50 µm, preferably 0.1 µm to 20 µm, and more preferably 0.1 µm to 10 µm. If the thickness is thinner than 0.1 μm, it is susceptible to failure due to pinhole defects, and suffers from a limitation in that leakage current occurs later. In addition, if the thickness exceeds 50 μm, cracks and surfaces may occur. There is a problem of uneven formation.

In the present invention, the planarization layer 230 functioning as a buffer layer is important in terms of surface flatness Ra (average of roughness). If the planarization layer 230 is not flat, defects occur when the connection electrode and the organic light emitting layer on the planarization layer are deposited. As a result, leakage current occurs, and thus the life of the organic light emitting part is limited. Accordingly, in the present invention, the surface flatness of the planarization layer 230 is preferably 0.5 nm to 5 nm, and more preferably 0.5 to 1 nm, based on the stylus method. In addition, the organic material having a roughness of about 5 nm to 50 nm or a root-mean-square roughness (RMS value) in the maximum peak-to-valley roughness in the present invention. It is desirable to provide an electroluminescent device. In this case, the luminance is increased at the same voltage, thereby improving the quality of the organic light emitting device.

Meanwhile, referring to the organic light emitting unit, the organic light emitting unit 220 is formed of an electrode layer and an organic layer, and the electrode layer 221 supplies a cathode electrode and a hole for supplying electrons. An organic light emitting layer 223 is disposed so that anode electrodes are disposed to face each other, and are disposed between these cathode electrodes and the anode electrode to emit light.

The electrode layer 221 may be formed of ITO, IZO, ZnO, or In ₂ O ₃ . The electrode layer 221 may be formed in a predetermined pattern.

In addition, the organic light emitting layer 223 disposed between the electrode layers 221 may be a low molecular or high molecular organic layer. When the low molecular organic layer is used, a hole injection layer (HIL), a hole transport layer (HTL), and an organic layer may be used. An emission layer (EML), an electron injection layer (EIL), an electron injection layer (ETL) and the like may be formed by stacking a single or a composite structure, and the low molecular weight organic layer may be formed by vacuum deposition. It can be formed by the method.

In the case of the polymer organic layer, the structure may include a hole transporting layer (HTL) and a light emitting layer (EML). In this case, PEDOT is used as the hole transporting layer, and polyvinylvinylene (PPV) and polyfluorene (PPV) are used as the emitting layer. Polymer organic materials such as polyfluorene) may be used and may be formed by screen printing or inkjet printing.

In the organic light emitting unit 220, as the anode and cathode voltages are applied to the anode electrode and the cathode electrode, holes injected from the anode electrode are moved to the light emitting layer, and electrons are injected from the cathode electrode to the light emitting layer. Electrons and holes recombine in to generate excitons, and as the excitons change from the excited state to the ground state, the fluorescent molecules in the light emitting layer emit light to form an image. The light emitting layer has a light emitting layer formed of a three-layer structure by sequentially stacking light emitting layers implementing red (R), green (G), and blue (B), or a light emitting layer having a complementary color relationship. It may be formed in a single layer structure consisting of a light emitting layer to implement.

In addition, the support substrate 210 and the sealing substrate may be bonded through the sealing material 240. The encapsulant 240 bonds the support substrate 210 to the encapsulation substrate through a thermosetting adhesive or a UV curable adhesive, and may be positioned along an edge of the encapsulation substrate. The sealant 240 forms a sealant 240 in a width of 0.1 to 2 mm at an edge portion of the sealing substrate in order to bond the supporting substrate 210 including the organic light emitting unit 220 to the sealing substrate. The sealant 240 may be formed by printing using a screen mask or by applying a sealant dispense or a syringe directly to a corresponding position. In one embodiment of the present invention was provided using a Nagase (XNR 5570) product as a UV (Ultra violate) curing adhesive provided in a rectangular frame shape installed outside the light emitting area.

On the other hand, the inner space partitioned by the support substrate 210 and the sealing substrate is preferably formed in a vacuum or to fill the inert gas. The inert gas is preferably filled with a gas such as nitrogen, neon or argon. In particular, when the inert gas is filled, it is in a state capable of adequately protecting the penetration of oxygen and moisture.

The present invention described above is not limited to the above-described embodiment and the accompanying drawings, and various substitutions, modifications, and changes are possible within the scope without departing from the technical spirit of the present invention. It will be evident to those who have knowledge of.

Claims (10)

A substrate made of a polymer resin material; And
The substrate is mixed with the light absorbing dye, the AR film or the projection type antireflection film is laminated on the outer surface of the substrate,
In the projection type anti-reflection film, the thickness (T) of the projection structure is 10 to 500 nm, the light and shade enhancement display device for a display device. delete The method of claim 1,
In the projection type anti-reflection film, the ratio of the thickness (T) and the height (H) of the projection structure is 1: 0.5 to 1: 3, the light and shade enhancement display device for a display device. The method of claim 1,
In the projection type anti-reflection film, the pitch of the projection structure is a clear light and shade enhancement film for display device, characterized in that 100 to 400 nm. The method of claim 1,
Brightness and contrast enhancement film for a display device, characterized in that hard coating or antifouling coating is additionally included on the outer surface of the AR film or projection antireflective film. The light and shade enhancement film according to any one of claims 1, 3, 4 and 5 is utilized in an organic light emitting device, the organic light emitting device,
Support substrates; An organic light emitting unit formed on one surface of the support substrate and including an organic light emitting layer between a pair of electrodes; An encapsulation substrate positioned above the organic light emitting part; And a sealing material for coupling the supporting substrate and the sealing substrate, wherein the sealing substrate is formed of the clear light and dark enhancement film. The method of claim 6,
The organic electroluminescent device, characterized in that the hard coating or antifouling coating is additionally included on the outermost surface of the sealing substrate. The method of claim 6,
And a planarization layer functioning as a buffer layer between an upper surface of the support substrate and a lower surface of the organic light emitting unit. The method of claim 6,
The internal space partitioned by the support substrate and the sealing substrate is filled with an inert gas of any one of nitrogen, neon or argon. The method of claim 6,
The organic electroluminescent device of claim 1, wherein a hole injection layer, a hole transport layer, an organic light emitting layer, an electron transport layer, and an electron injection layer are sequentially stacked between the electrode layer and the electrode layer.

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