JP6939833B2 - Image display device - Google Patents

Description

The present invention relates to an image display device.

Image display devices have been widely put into practical use in mobile phones, tablet terminals, personal computers, televisions, PDAs, electronic dictionaries, car navigation systems, music players, digital cameras, digital video cameras and the like. With the progress of miniaturization and weight reduction of image display devices, their use is no longer limited to offices and indoors, but their use is also expanding outdoors and while traveling by car or train.

Under such circumstances, the chances of visually recognizing an image display device through a polarizing filter such as sunglasses are increasing. On the other hand, it has been proposed to use an alignment film for an image display device due to various factors. However, when an alignment film is used in the image display device, its subrefractive property distorts the deflection characteristics of the light emitted from the polarizing plate, and as a result, when the image is visually recognized by the polarizing filter, the color tone such as rainbow spots appears. There is a problem that visibility deteriorates due to disturbance (Patent Document 1).

WO2011 / 058774

Therefore, one object of the present invention is to improve the visibility when the image display device using the alignment film is visually recognized through the polarizing filter.

The present inventors have conducted research day and night to solve the above problems, and have found that the above problems can be solved by controlling the retardation of the alignment film. Based on such findings, the present inventors have repeated further studies and improvements to complete the present invention.

A typical invention is as follows.
Item 1.
(1) Image display cell,
(2) A polarizing element arranged on the viewing side of the image display cell, and (3) an alignment film having a retardation of 3000 or more and 150,000 nm or less arranged on the viewing side of the polarizing element.
An image display device having.
Item 2.
Item 2. The image display device according to Item 1, wherein the angle formed by the polarizing axis of the polarizer and the alignment spindle of the alignment film is approximately 45 degrees.
Item 3.
Item 2. The image display device according to Item 1 or 2, wherein the image display cell is an organic EL cell.

According to the present invention, the visibility of the image display device is improved. In particular, the deterioration of image quality typified by rainbow spots that occurs when visually recognized through a polarizing filter is reduced. In this document, "rainbow spot" is a concept including "color spot", "color shift", and "interference color".

A schematic cross-sectional view of a typical organic EL display device is shown. A schematic cross-sectional view of a typical liquid crystal display device is shown. A schematic cross-sectional view of a typical organic EL cell is shown.

The image display device typically has an image display cell and a polarizing plate. An organic EL cell or a liquid crystal cell is typically used as the image display cell. A typical schematic diagram of an image display device (organic EL display device) using an organic EL cell as an image display cell is shown in FIG. 1, and a representative of an image display device (liquid crystal display device) using a liquid crystal cell as an image display cell. A schematic diagram is shown in FIG. Hereinafter, a typical structure of the image display device will be described with reference to FIGS. 1 or 2, but the structure of the image display device is not limited to these, and various changes can be made.

In this document, the side on which the image of the image display device is displayed (the side on which a human visually recognizes the image) is referred to as the "viewing side", and the side opposite to the viewing side (that is, the organic EL display device also functions as a light source). The side where the EL cell is set and the side where the light source is arranged in the liquid crystal display device) are referred to as "light source side". In FIGS. 1 and 2, the right side is the viewing side and the left side is the light source side.

As shown in FIG. 1, the organic EL display device (E1) may have an organic EL cell (E4), a polarizing plate (E5), and a touch panel (E6). A quarter wave plate (E16) may be provided between the organic EL cell (E4) and the polarizing plate (E5). The polarizing plate (E5) is typically provided on the visible side of the organic EL cell (E4), and has a structure in which a polarizing element protective film (E10a, E10b) is laminated on both sides of a film called a polarizing element (E8). Have. The touch panel (E6) is typically provided on the viewing side of the viewing side polarizing plate (E5). The touch panel (E6) typically has a structure in which two transparent conductive films (E11, E12) are arranged via a spacer (E13). The transparent conductive film (E11, E12) has a structure in which a base film (E11a, E12a) and a transparent conductive layer (E11b, E12b) are laminated. On the light source side and the visual recognition side of the touch panel (E6), shatterproof films (E14, E15) which are transparent substrates may be provided via an arbitrary adhesive layer.

As shown in FIG. 2, the liquid crystal display device (L1) may have a light source (L2), a liquid crystal cell (L4), and a touch panel (L6). A polarizing plate (light source side polarizing plate (L3) and viewing side polarizing plate (L5)) is typically provided on both the light source side and the visual viewing side of the liquid crystal cell (L4), respectively. Each polarizing plate (L3, L5) typically has a structure in which a polarizing element protective film (L9a, L9b, L10a, L10b) is laminated on both sides of a film called a polarizing element (L7, L8). In this document, the polarizing plate (L5) existing on the viewing side of the image display cell is also referred to as a “visualizing side polarizing plate”, and the polarizing element (L8) constituting the polarizing plate (L8) is also referred to as a “visually visible side polarizing element”. The touch panel (L6) is typically provided on the viewing side of the viewing side polarizing plate (L5). The touch panel (L6) typically has a structure in which two transparent conductive films (L11, L12) are arranged via a spacer (L13). The transparent conductive film (L11, L12) has a structure in which a base film (L11a, L12a) and a transparent conductive layer (L11b, L12b) are laminated. Further, on the light source side and the visual recognition side of the touch panel (L6), shatterproof films (L14, L15) which are transparent substrates may be provided via an arbitrary adhesive layer.

In addition, in FIGS. For example, one shatterproof film may be provided on the visible side of the visible polarizing plate. The touch panel is not limited to the above-mentioned resistance film type touch panel, and other types of touch panels such as a projection type capacitance type can be used. For example, the number of transparent conductive films may be one. The shatterproof film does not necessarily have to be arranged on both sides of the touch panel, and may be arranged on either side or may not be arranged on both sides.

<Position of alignment film>
Alignment films can be used in image display devices for a variety of purposes. In this document, the alignment film means a polymer film having birefringence. From the viewpoint of improving visibility, the image display device preferably has an alignment film having a retardation of 3000 nm or more and 150,000 nm or less on the viewing side of the polarizing element on the viewing side. In this document, an alignment film having a retardation of 3000 nm or more and 150,000 nm or less is also referred to as a "high retardation alignment film". Therefore, in the image display devices shown in FIGS. 1 and 2, the alignment film is typically a polarizer protective film (E10b, L10b) (hereinafter, "visualizing side") that is on the visual viewing side of the visual viewing side polarizers (E8, L8). Substrate films (E11a, L11a) of transparent conductive films (E11, L11) arranged on the light source side from spacers (E13, L13) (hereinafter referred to as "polarizer protective film") (hereinafter, "light source side base film"). , The base film (E12a, L12a) of the transparent conductive film (E12, L12) on the viewing side of the spacers (E13, L13) (hereinafter referred to as "visual side base film"), viewing side polarization. The shatterproof film (E14, L14) (hereinafter referred to as "light source side shatterproof film") and / or the visual side between the child protective film (E10b, L10b) and the light source side base film (E11a, L11a). It can be used as a shatterproof film (E15, L15) (hereinafter, referred to as "visually visible shatterproof film") on the visual side of the base film (E12a, L12a).

The number of high retardation oriented films used in the image display device is arbitrary and is not particularly limited, but it is preferable that at least one high retardation oriented film is used at the above-mentioned positions. As a typical example of such an image display device, in the organic EL display device or the liquid crystal display device shown in FIGS. 1 or 2, a high retardation alignment film is placed at a position corresponding to a visible side shatterproof film (E15, L15). Examples thereof include an organic EL display device or a liquid crystal display device provided. In this representative example, the high retardation oriented film may have an antireflection layer on the surface on the visible side thereof.

As another typical example of the image display device, there is a "surface cover plate integrated touch panel" in which a capacitance type touch panel is provided on a surface cover plate such as glass, and this "surface cover plate integrated touch panel" is provided. Incorporated with a high retardation alignment film. The following patterns (A) to (F) can be exemplified as a specific configuration of this "surface cover plate integrated touch panel".

(A) A transparent conductive layer is provided on the light source side or the visible side of the surface cover plate, and a high retardation oriented film is attached as a shatterproof film on the surface of the transparent conductive layer or on the surface of the surface cover plate opposite to the transparent conductive layer. , Touch panel with integrated surface cover plate. The transparent conductive layer may be provided on either the light source side or the visible side of the surface cover plate, but is preferably provided on the light source side.

(B) A touch panel with an integrated surface cover plate, in which glass plates are laminated on both sides of a high retardation alignment film to form laminated glass, and a transparent conductive layer is provided on the light source side of the laminated glass.

(C) A surface cover plate integrated touch panel in which a transparent conductive layer is provided on one side of a high retardation film and the transparent conductive layer is attached to the light source side or the visual recognition side of the surface cover plate. When it is attached to the light source side, it may be attached to either the surface of the high retardation alignment film on which the transparent conductive layer is not provided or the surface of the transparent conductive layer. When sticking to the visual side, it is preferable to stick the surface of the transparent conductive layer and the surface cover plate.

(D) A touch panel with an integrated surface cover plate, which is provided with transparent conductive layers on both sides of a high retardation film and attached to the light source side of the surface cover plate.

It is preferable to provide an antireflection layer on the innermost surface (the surface closest to the light source) of the touch panel integrated with the surface cover plate. When the innermost surface is a transparent conductive layer, an electrode protective coating layer may be provided and an antireflection layer may be provided on the electrode protective coating layer. Further, an antireflection layer, an antiglare layer, an antistatic layer, an antifouling layer and the like may be provided on the outermost surface (the surface on the most visible side) of the touch panel integrated with the surface cover plate. A substrate-less optical adhesive is preferably used for laminating each part.

(E) A surface cover plate integrated touch panel in which a transparent conductive layer is provided on one or both sides of a film having no birefringence, and a surface cover plate and a high retardation alignment film are bonded to the transparent conductive layer. Here, if the outermost surface (the surface on the most visible side of the image display device) is a cover plate or a high retardation oriented film, the bonding order is arbitrary.

(F) A surface cover plate integrated touch panel in which a transparent conductive layer is provided on one side or both sides of a sheet-like material such as glass, and a surface cover plate and a high retardation alignment film are bonded to the transparent conductive layer. Here, if the outermost surface (the surface on the most visible side of the image display device) is a cover plate or a high retardation oriented film, the other order of bonding is arbitrary.

The lower limit of retardation of the high retardation oriented film is preferably 4500 nm or more, preferably 6000 nm or more, preferably 8000 nm or more, and preferably 10000 nm or more from the viewpoint of reducing iridescent spots. On the other hand, the upper limit of the retardation of the high retardation oriented film is such that even if a polyester film having a higher retardation is used, the effect of further improving the visibility cannot be substantially obtained, and the orientation depends on the height of the retardation. Since the thickness of the film also tends to increase, it is set to 150,000 nm from the viewpoint that it may be contrary to the demand for thinning, but it is theoretically possible to set it to a higher value. When the image display device has two or more high retardation oriented films, the retardations may be the same or different.

From the viewpoint of more effectively suppressing rainbow spots, the ratio (Re / Rth) of the retardation (Re) to the thickness direction retardation (Rth) of the high retardation oriented film is preferably 0.2 or more. It is preferably 0.5 or more, preferably 0.6 or more. The thickness direction retardation means the average value of the retardation obtained by multiplying the two birefringences ΔNxz and ΔNyz when viewed from the cross section in the thickness direction of the film by the film thickness d, respectively. The larger Re / Rth, the more isotropic the action of birefringence, and the more effectively the occurrence of iridescent spots on the screen can be suppressed. In addition, when it is simply described as "retamination" in this document, it means in-plane retardation.

The maximum value of Re / Rth is 2.0 (that is, a perfect uniaxially symmetric film), but the mechanical strength in the direction orthogonal to the orientation direction tends to decrease as the film approaches the perfect uniaxially symmetric film. be. Therefore, the upper limit of Re / Rth of the polyester film is preferably 1.2 or less, preferably 1.0 or less. Even if the ratio is 1.0 or less, it is possible to satisfy the viewing angle characteristics (about 180 degrees left and right, 120 degrees up and down) required for an image display device.

The retardation of the alignment film can be measured according to a known method. Specifically, it can be obtained by measuring the refractive index and the thickness in the biaxial direction. It can also be obtained using a commercially available automatic birefringence measuring device (for example, KOBRA-21ADH: manufactured by Oji Measuring Instruments Co., Ltd.).

The angle formed by the alignment spindle of the high retardation alignment film and the polarization axis of the viewing side polarizer (assuming that the high retardation alignment film and the polarizer are in the same plane) is not particularly limited, but reduces rainbow spots. It is preferable that the temperature is close to 45 degrees (approximately 45 degrees). For example, the angle is 45 degrees ± 20 degrees or less, preferably 45 degrees ± 15 degrees, preferably 45 degrees ± 10, preferably 45 degrees ± 5 degrees, preferably 45 degrees ± 3 degrees, 45 degrees ± 2 degrees, 45 degrees ± 1 degree, 45 degrees. In this document, the term "less than or equal to" means that it applies only to the number following "±". Therefore, for example, the above-mentioned "45 degrees ± 20 degrees or less" means that fluctuations in the range of 20 degrees up and down around 45 degrees are allowed.

Arranging the polarizer and the high retardation alignment film so that the polarizing axis and the alignment spindle satisfy a certain angle as described above is, for example, to arrange the cut high retardation alignment film with the polarization axis whose alignment spindle is the polarizer. It can be carried out by a method of arranging the film at a specific angle or a method of diagonally stretching a high-polarization oriented film.

The orientation principal axis of the high retardation alignment film is preferably arranged in the image display device so as to be parallel to the vertical axis or the horizontal axis of the rectangular display screen. When the orientation main axis of the high retardation alignment film is substantially parallel to the vertical axis of the display, rainbow spots are suppressed and visibility is excellent even when the screen is observed from an oblique direction (horizontal direction) instead of from the front. be. On the other hand, when the orientation principal axis of the high retardation alignment film almost coincides with the horizontal direction of the display screen, rainbow spots are suppressed and visibility is excellent even when the screen is observed from an oblique direction (vertical direction) instead of from the front. Because.

The image display device may have a retardation alignment film of less than 3000 nm at an arbitrary position as long as it is provided with at least one high retardation alignment film on the viewing side of the polarizing element on the viewing side. Such oriented films are known and are also commercially available.

The high retardation oriented film can be produced by appropriately selecting a known method. For example, the high retardation alignment film is a polyester resin, a polycarbonate resin, a polystyrene resin, a syndiotactic polystyrene resin, a polyether ether ketone resin, a polyphenylene sulfide resin, a cycloolefin resin, a liquid crystal polymer resin, and a cellulose resin with a liquid crystal compound. It can be produced using one or more selected from the group consisting of added resins. Therefore, in the high retardation oriented film, a liquid crystal compound is added to a polyester film, a polycarbonate film, a polystyrene film, a syndiotactic polystyrene film, a polyether ether ketone film, a polyphenylene sulfide film, a cycloolefin film, a liquid crystal film, and a cellulose resin. It can be a film.

Preferred raw material resins for high retardation oriented films are polycarbonate and / or polyester, syndiotactic polystyrene. These resins are excellent in transparency as well as thermal and mechanical properties, and retardation can be easily controlled by stretching. Polyesters typified by polyethylene terephthalate and polyethylene naphthalate are preferable because they have a large intrinsic birefringence and a large retardation can be obtained relatively easily even if the film thickness is thin. In particular, polyethylene naphthalate has a large intrinsic birefringence among polyesters, and is therefore suitable for cases where it is desired to have a particularly high retardation or when it is desired to reduce the film thickness while maintaining a high retardation. Taking polyester resin as a typical example, a more specific method for producing a high retardation oriented film will be described later.

An oriented film having a retardation of less than 3000 nm can be produced by appropriately selecting a known method. For example, polyester resin, acetate resin, polyether sulfone resin, polycarbonate resin, polyamide resin, polyimide resin, polyolefin resin (polyethylene resin, polypropylene resin, cyclic polyolefin, etc.), (meth) acrylic resin, polyvinyl chloride resin, polyvinylidene chloride. A resin selected from the group consisting of resins, polystyrene resins, polyvinyl alcohol resins, polyarylate resins, polyphenylene sulfide resins, cellulose acetate resins (triacetyl cellulose, etc.) and the like can be obtained as a raw material. Among these, polyester resin and polyolefin resin are preferable, polyester resin is more preferable, and polyethylene terephthalate and / or polypropylene resin is more preferable.

<Manufacturing method of alignment film>
Hereinafter, a method for producing an alignment film including a high retardation alignment film will be described using a polyester film as an example. The polyester film can be obtained by condensing an arbitrary dicarboxylic acid with a diol. Examples of the dicarboxylic acid include terephthalic acid, isophthalic acid, orthophthalic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, and diphenylcarboxylic acid. Acid, diphenoxyetanedicarboxylic acid, diphenylsulfoncarboxylic acid, anthracendicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, hexahydroterephthalic acid, hexahydroisophthalic acid Acids, malonic acids, dimethylmalonic acids, succinic acids, 3,3-diethylsuccinic acid, glutaric acid, 2,2-dimethylglutaric acid, adipic acid, 2-methyladipic acid, trimethyladipic acid, pimelic acid, azelaic acid, Examples thereof include dimer acid, sebacic acid, suberic acid, dodecadicarboxylic acid and the like.

Examples of the diol include ethylene glycol, propylene glycol, hexamethylene glycol, neopentyl glycol, 1,2-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, decamethylene glycol, 1,3-propanediol, and 1,4. Examples thereof include -butanediol, 1,5-pentanediol, 1,6-hexadiol, 2,2-bis (4-hydroxyphenyl) propane, and bis (4-hydroxyphenyl) sulfone.

As the dicarboxylic acid component and the diol component constituting the polyester film, one kind or two or more kinds may be used respectively. Specific examples of the polyester resin constituting the polyester film include polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polyethylene naphthalate and the like, preferably polyethylene terephthalate and polyethylene terephthalate, and more preferably polyethylene terephthalate. be. The polyester resin may contain other copolymerization components, and the proportion of the copolymerization components is preferably 3 mol% or less, more preferably 2 mol% or less, still more preferably 1.5 mol% or less from the viewpoint of mechanical strength. be. These resins are excellent in transparency as well as thermal and mechanical properties. In addition, the retardation of these resins can be easily controlled by stretching.

The polyester film can be obtained according to a general manufacturing method. Specifically, a non-oriented polyester obtained by melting a polyester resin and extruding it into a sheet is stretched in the vertical direction at a temperature equal to or higher than the glass transition temperature by utilizing the speed difference of the rolls, and then laterally stretched by a tenter. An oriented polyester film can be mentioned by stretching and heat-treating. The polyester film may be a uniaxially stretched film or a biaxially stretched film. The high retardation alignment film may be stretched at an angle of 45 degrees.

The production conditions for obtaining the polyester film can be appropriately set according to a known method. For example, the longitudinal stretching temperature and the transverse stretching temperature are usually 80 to 130 ° C., preferably 90 to 120 ° C. The longitudinal stretching ratio is usually 1.0 to 3.5 times, preferably 1.0 to 3.0 times. The lateral stretching ratio is usually 2.5 to 6.0 times, preferably 3.0 to 5.5 times.

Controlling the retardation within a specific range can be performed by appropriately setting the stretching ratio, stretching temperature, and film thickness. For example, the higher the difference in stretching ratio between longitudinal stretching and transverse stretching, the lower the stretching temperature, and the thicker the film, the easier it is to obtain high retardation. On the contrary, the lower the difference in stretching ratio between the longitudinal stretching and the transverse stretching, the higher the stretching temperature, and the thinner the film thickness, the easier it is to obtain lower retardation. Further, the higher the stretching temperature and the lower the total stretching ratio, the easier it is to obtain a film having a low ratio (Re / Rth) of retardation and retardation in the thickness direction. On the contrary, the lower the stretching temperature and the higher the total stretching ratio, the higher the ratio of retardation to thickness direction retardation (Re / Rth) can be obtained. Further, the heat treatment temperature is usually preferably 140 to 240 ° C, preferably 180 to 240 ° C.

In order to suppress fluctuations in retardation in the polyester film, it is preferable that the thickness unevenness of the film is small. If the longitudinal stretching ratio is lowered in order to make a difference in retardation, the value of the longitudinal thickness spot may increase. Since there is a region where the value of the vertical thickness spot becomes very high in a specific range of the draw ratio, it is desirable to set the film forming conditions so as to exclude such a range.

The thickness unevenness of the oriented polyester film is preferably 5.0% or less, further preferably 4.5% or less, further preferably 4.0% or less, and 3.0% or less. Is particularly preferred. The thickness unevenness of the film can be measured by any means. For example, a tape-shaped sample (length 3 m) continuous in the flow direction of the film is taken, and a commercially available measuring instrument (for example, an electronic micrometer Millitron 1240 manufactured by Seiko EM Co., Ltd.) is used to measure 100 at a pitch of 1 cm. The thickness of the points is measured, the maximum value (dmax), the minimum value (dmin), and the average value (d) of the thickness are obtained, and the thickness unevenness (%) can be calculated by the following formula.
Thickness spot (%) = ((dmax-dmin) / d) × 100

<Image display cell and light source>
In an image display device, the light emitted from the image display cell preferably has a continuous and wide emission spectrum from the viewpoint of suppressing rainbow spots. Here, the "continuous and wide emission spectrum" means an emission spectrum in which there is no wavelength region in which the light intensity becomes zero in a wavelength region of at least 450 to 650 nm, preferably in the visible light region. The visible light region is, for example, a wavelength region of 400 to 760 nm, and may be 360 to 760 nm, 400 to 830 nm, or 360 to 830 nm.

When the image display device includes an organic EL cell as an image display cell, the organic EL cell itself has a function as a light source having a continuous and wide emission spectrum. On the other hand, when the image display device includes a liquid crystal cell as an image display cell, it is preferable to include a white light source having a continuous and wide emission spectrum.

The method and structure of the white light source having a continuous and wide emission spectrum are not particularly limited, and may be, for example, an edge light method or a direct type method. Examples of such a white light source include a white light emitting diode (white LED). White LEDs include phosphor-type ones (that is, blue light using a compound semiconductor, and an element that emits white light by combining a light emitting diode that emits ultraviolet light and a phosphor) and an organic light-emitting diode. : OLED) and the like. White light consisting of a blue light emitting diode using a compound semiconductor and a yttrium aluminum garnet yellow phosphor combined from the viewpoint of having a continuous and wide emission spectrum and excellent luminous efficiency. Light emitting diodes are preferred.

As the organic EL cell, an organic EL cell known in the art can be appropriately selected and used. The use of organic EL cells is preferred in that it has a wide viewing angle, high contrast, and fast response. A schematic cross-sectional view of a typical organic EL cell is shown in FIG. The organic EL cell (E4) typically has an anode (E18) which is a transparent electrode, an organic light emitting layer (E19), and a cathode (E20) which is a metal electrode on a transparent substrate (E17) in this order from the visual side. It is a luminescent material having a laminated structure (organic electroluminescence luminescent material). When a voltage is applied between the anode and the cathode, the organic EL cell emits light by recombination of holes injected from the anode and electrons injected from the cathode in the organic light emitting layer. do.

Any transparent substrate may be adopted as the transparent substrate. For example, the transparent substrate can be selected from the group consisting of glass substrates, ceramic substrates, semiconductor substrates, metal substrates, and plastic substrates. Specific examples of the plastic substrate include a transparent resin film conventionally used as a base film used for a touch panel described later. The transparent substrate may be provided with a surface treatment layer, if necessary. Examples of the surface treatment layer include a moisture permeation prevention layer, a gas barrier layer, a hard coat layer, an undercoat layer and the like.

Examples of the material constituting the anode and the cathode include metals, metals oxide, alloys, electrically conductive compounds, and mixtures thereof. More specific materials constituting the anode include conductive transparent materials such as gold, silver, chromium, nickel, copper iodide, indium tin oxide (ITO), tin oxide, and zinc oxide. More specific materials constituting the cathode include magnesium, aluminum, indium, lithium, sodium, cesium, silver, magnesium-silver alloy, magnesium-indium alloy, lithium-aluminum alloy and the like.

The thickness of the anode and the cathode can be arbitrarily set according to the material constituting the anode and the cathode. The thickness of the anode can be appropriately set, for example, from the range of 10 nm to 200 nm, preferably 10 nm to 100 nm. The thickness of the cathode is, for example, 10 nm to 1000 nm, and is preferably set from the range of 10 nm to 200 nm.

The organic light emitting layer is a layer having a function of providing a field for recombination of holes and electrons to emit light when a voltage is applied. The organic light emitting layer contains an organic light emitting material and may have a single layer structure or a laminated structure of two or more layers. In the case of a laminated structure, each layer may emit light with a different emission color. The thickness of the organic light emitting layer is arbitrary and can be appropriately set in the range of, for example, 3 nm to 3 μm.

The organic light emitting material used for the organic light emitting layer can be appropriately selected from any light emitting materials. Specifically, olefin-based luminescent materials such as 4,4'-(2,2-diphenylvinyl) biphenyl; 9,10-di (2-naphthyl) anthracene, 9,10-bis (3,5-diphenylphenyl). ) Anthracene, 9,10-bis (9,9-dimethylfluorenyl) anthracene, 9,10- (4- (2,2-diphenylvinyl) phenyl) anthracene, 9,10'-bis (2-biphenylyl) Anthracene-based luminescent materials such as -9,9'-bisanthracene, 9,10,9', 10'-tetraphenyl-2,2'-bianthracene, 1,4-bis (9-phenyl-10-anthracene) benzene Spiro-based luminescent materials such as 2,7,2', 7'-tetrakis (2,2-diphenylvinyl) spirobifluorene; 4,4'-dicarbazolbiphenyl, 1,3-dicarbazolylbenzene, etc. Carbazole-based luminescent material; can be appropriately selected from the group consisting of pyrene-based luminescent materials such as 1,3,5-tripireninbenzene and the like.

The organic EL cell includes a sealing member formed so as to cover the organic EL element in order to shield the organic EL element composed of the anode, the organic light emitting layer, and the cathode on the base material from the outside air. Is also good. By providing the sealing member, it is possible to prevent deterioration of the light emitting characteristics of the organic light emitting layer due to moisture and oxygen in the outside air.

The organic EL device may further include any member (eg, a hole injection layer, a hole transport layer, an electron transport layer, and / or an electron transport layer) at any suitable position.

When an organic EL cell is used as an image display cell, a polarizing plate in an image display device is usually not essential. However, since the thickness of the organic light emitting layer is as thin as about 10 nm, the external light is reflected by the metal electrode and emitted to the visual recognition side again, and when visually recognized from the outside, the display surface of the organic EL display device looks like a mirror surface. In some cases. In order to shield such specular reflection of external light, it is preferable to provide a polarizing plate on the visual side of the organic EL cell and further provide a 1/4 wave plate between the organic EL cell and the polarizing plate. .. By forming a circularly polarizing plate by combining these viewing-side polarizing plates and a 1/4 wave plate, the external light reflected on the mirror surface by the metal electrode of the organic EL cell is shielded by the circularly polarizing plate, so that an image is displayed. It is possible to suppress a decrease in the visibility of the device.

As the liquid crystal cell, any liquid crystal cell that can be used in the liquid crystal display device can be appropriately selected and used, and the method and structure thereof are not particularly limited. For example, a liquid crystal cell such as a VA mode, an IPS mode, a TN mode, an STN mode, or a bend orientation (π type) can be appropriately selected and used. Therefore, as the liquid crystal cell, a liquid crystal made of a known liquid crystal material or a liquid crystal material that can be developed in the future can be appropriately selected and used. A preferred liquid crystal cell in one embodiment is a transmissive liquid crystal cell.

<Polarizer and polarizer protective film>
The polarizing plate has a structure in which both sides of a film-shaped polarizing element are sandwiched between two protective films (sometimes referred to as "polarizer protective films"). As the polarizing element, any polarizing element (or polarizing film) used in the art can be appropriately selected and used. As a typical polarizer, a polyvinyl alcohol (PVA) film or the like dyed with a dichroic material such as iodine can be mentioned, but the present invention is not limited to this, and is known and developed in the future. The obtained polarizer can be appropriately selected and used.

Commercially available PVA films can be used, for example, "Kuraray Vinylon (manufactured by Kuraray Co., Ltd.)", "Tosero Vinylon (manufactured by Tohcello Co., Ltd.)", "Nigo Vinylon (manufactured by Nippon Synthetic Chemical Co., Ltd.)". (Manufactured)] and the like. Examples of the bicolor material include iodine, a diazo compound, a polymethine dye and the like.

The polarizer can be obtained by any method. For example, a PVA film dyed with a dichroic material is uniaxially stretched in an aqueous boric acid solution, and washed and dried while maintaining the stretched state. Can be obtained by The draw ratio of uniaxial stretching is usually about 4 to 8 times, but is not particularly limited. Other manufacturing conditions and the like can be appropriately set according to a known method.

The protective film on the visual side of the polarizing element on the visual side (protective film on the polarizing element on the visual side) can be a high retardation alignment film or any film conventionally used as a polarizing element protective film, but is limited thereto. is not it.

The type of the protective film on the light source side of the polarizing element on the viewing side and the protective film on the polarizing element on the light source side are arbitrary, and a film conventionally used as a protective film can be appropriately selected and used. From the viewpoint of handleability and availability, for example, triacetyl cellulose (TAC) film, acrylic film, cyclic olefin film (for example, norbornene film), polypropylene film, polyolefin film (for example, TPX) and the like. It is preferable to use one or more non-polyrefractive films selected from the group consisting of.

In one embodiment, the light source side protective film of the viewing side polarizer and the viewing side protective film of the light source side polarizing element are preferably optical compensation films having an optical compensation function. Such an optical compensation film can be appropriately selected according to each method of the image display cell, and for example, a liquid crystal compound (for example, a discotic liquid crystal compounding portion and / or a birefractive compound) is dispersed in triacetyl cellulose. Selected from the group consisting of a resin, a cyclic olefin resin (for example, norbornene resin), a propionyl acetate resin, a polycarbonate film resin, an acrylic resin, a styrene acrylonitrile copolymer resin, a lactone ring-containing resin, an imide group-containing polyolefin resin, and the like. The ones obtained from one or more kinds can be mentioned.

Since the optical compensation films are commercially available, they can be appropriately selected and used. For example, "Wide View-EA" and "Wide View-T" for TN method (manufactured by Fujifilm), "Wide View-B" for VA method (manufactured by Fujifilm), VA-TAC (Konica Minolta) (Manufactured by), "Zeonor Film" (manufactured by Nippon Zeon), "Arton" (manufactured by JSR), "X-plat" (manufactured by Nitto Denko), and "Z-TAC" for IPS system (manufactured by Fujifilm) ), "CIG" (manufactured by Nitto Denko Corporation), "P-TAC" (manufactured by Okura Industrial Co., Ltd.) and the like.

The polarizer protective film can be laminated directly on the polarizer or via an adhesive layer. From the viewpoint of improving adhesiveness, it is preferable to laminate via an adhesive. The adhesive is not particularly limited and any adhesive can be used. From the viewpoint of thinning the adhesive layer, an aqueous type (that is, an adhesive component dissolved in water or dispersed in water) is preferable. For example, when a polyester film is used as the polarizer protective film, a polyvinyl alcohol-based resin, a urethane resin, or the like is used as the main component, and an isocyanate-based compound, an epoxy compound, or the like is blended as necessary in order to improve the adhesiveness. The composition can be used as an adhesive. The thickness of the adhesive layer is preferably 10 μm or less, more preferably 5 μm or less, and even more preferably 3 μm or less.

When a TAC film is used as the polarizer protective film, it can be bonded using a polyvinyl alcohol-based adhesive. When a film having low moisture permeability such as an acrylic film, a cyclic olefin film, a polypropire film, or TPX is used as the polarizer protective film, it is preferable to use a photocurable adhesive as the adhesive. Examples of the photocurable resin include a mixture of a photocurable epoxy resin and a photocationic polymerization initiator.

The thickness of the polarizer protective film is arbitrary, and can be appropriately set, for example, in the range of 15 to 300 μm, preferably in the range of 30 to 200 μm.

<Touch panel, transparent conductive film, base film, shatterproof film>
The image display device may include a touch panel. The type and method of the touch panel are not particularly limited, and examples thereof include a resistive touch panel and a capacitance type touch panel. The touch panel usually has one or more transparent conductive films regardless of the method. The transparent conductive film has a structure in which a transparent conductive layer is laminated on a base film. As the base film, a high retardation oriented film or another film conventionally used as a base film or a rigid plate such as a glass plate can be used.

Examples of other films conventionally used as the base film include various transparent resin films. For example, polyester resin, acetate resin, polyether sulfone resin, polycarbonate resin, polyamide resin, polyimide resin, polyolefin resin, (meth) acrylic resin, polyvinyl chloride resin, polyvinylidene chloride resin, polystyrene resin, polyvinyl alcohol resin, polyarylate. A film obtained from one or more kinds of resins selected from the group consisting of resins, polyphenylene sulfide resins and the like can be used. Among these, polyester resin, polycarbonate resin, and polyolefin resin are preferable, and polyester resin is more preferable.

The thickness of the base film is arbitrary, but is preferably in the range of 15 to 500 μm.

The surface of the base film may be subjected to an etching treatment such as sputtering, corona discharge, flame, ultraviolet irradiation, electron beam irradiation, chemical conversion, oxidation, or an undercoating treatment in advance. This makes it possible to improve the adhesion with the transparent conductive layer or the like provided on the base film. Further, before providing the transparent conductive layer or the like, the surface of the base film may be dust-removed and cleaned by solvent cleaning, ultrasonic cleaning, or the like, if necessary.

The transparent conductive layer may be laminated directly on the base film, but can be laminated via an easy-adhesion layer and / or various other layers. Examples of other layers include a hard coat layer, an index matching (IM) layer, a low refractive index layer, and the like. The following six patterns can be mentioned as a typical laminated structure of the transparent conductive film, but the laminated structure is not limited to these.
(1) Base film / Easy-adhesion layer / Transparent conductive layer (2) Base film / Easy-adhesion layer / Hard coat layer / Transparent conductive layer (3) Base film / Easy-adhesion layer / IM (index matching) layer / Transparent conductive layer (4) Base film / Easy-adhesion layer / Hard coat layer / IM (index matching) layer / Transparent conductive layer (5) Base film / Easy-adhesion layer / Hard coat layer (also serves as IM with high refractive index ) / Transparent conductive layer (6) Base film / Easy-adhesion layer / Hard coat layer (high refractive index) / Low refractive index layer / Transparent conductive thin film

Since the IM layer itself has a laminated structure of a high refractive index layer / a low refractive index layer (the transparent conductive thin film side is a low refractive index layer), by using this, the ITO pattern is displayed when the liquid crystal display screen is viewed. Can be obscured. As described in (6) above, the high refractive index layer of the IM layer and the hard coat layer can be integrated, which is preferable from the viewpoint of thinning.

The configurations (3) to (6) above are particularly suitable for use in a capacitive touch panel. Further, the above configurations (2) to (6) are preferable from the viewpoint of preventing oligomers from depositing on the surface of the base film, and a hard coat layer may be provided on the other side of the base film. preferable.

The transparent conductive layer on the base film is formed of a conductive metal oxide. The conductive metal oxide constituting the transparent conductive layer is not particularly limited, and is composed of the group consisting of indium, tin, zinc, gallium, antimony, titanium, silicon, zirconium, magnesium, aluminum, gold, silver, copper, palladium and tungsten. Conductive metal oxides of at least one selected metal are used. The metal oxide may further contain the metal atoms shown in the above group, if necessary. Preferred transparent conductive layers are, for example, a tin-doped indium oxide (ITO) layer and an antimony-doped tin oxide (ATO) layer, and more preferably an ITO layer. Further, it may be Ag nanowire, Ag ink, self-assembled conductive film of Ag ink, mesh-like electrode, CNT ink, or conductive polymer.

The thickness of the transparent conductive layer is not particularly limited, but is preferably 10 nm or more, more preferably 15 to 40 nm, and further preferably 20 to 30 nm. When the thickness of the transparent conductive layer is 15 nm or more, it is easy to obtain a good continuous coating having ^{a surface resistance of, for example, 1 × 10 3 Ω / □ or less.} Further, when the thickness of the transparent conductive layer is 40 nm or less, a more transparent layer can be obtained.

The transparent conductive layer can be formed according to a known procedure. For example, a vacuum vapor deposition method, a sputtering method, and an ion plating method can be exemplified. The transparent conductive layer may be amorphous or crystalline. As a method for forming the crystalline transparent conductive layer, it is preferable to form the amorphous film once on the substrate and then heat and crystallize the amorphous film together with the flexible transparent substrate.

The transparent conductive film of the present invention may be patterned by removing a part of the transparent conductive layer in the plane. The transparent conductive film in which the transparent conductive layer is patterned has a pattern forming portion in which the transparent conductive layer is formed on the base film and a pattern opening having no transparent conductive layer on the base film. Have. Examples of the shape of the pattern forming portion include a striped shape and a square shape.

It is preferable to have one or more shatterproof films as the transparent substrate on the light source side and / or the visual recognition side of the touch panel. As the shatterproof film, the above-mentioned high retardation alignment film or various films conventionally used as the shatterproof film (for example, the transparent resin film described for the above-mentioned base film) can also be used. When two or more shatterproof films are provided, they may be made of the same material or may be different.

When the alignment film is used as a shatterproof film on the surface cover plate of the image display device, the alignment film may be arranged on the light source side or the visual recognition side of the surface cover plate. Further, it may have a laminated glass structure in which glass is laminated on both sides of the alignment film. When the alignment film is on the light source side of the surface cover plate, it is preferable to provide an antireflection layer on the side opposite to the surface cover plate of the alignment film. A bright and clear image can be obtained by providing the antireflection layer.

When the alignment film is used as a shatterproof film, it is preferable to impart an ultraviolet absorbing function to the alignment film. The ultraviolet absorbing function can be imparted by adding an ultraviolet absorber to the alignment film, or by applying an ultraviolet absorbing coating to the visible side of the alignment film. When the alignment film is on the visible side of the surface cover plate, it is preferable to provide an antireflection layer, an antiglare layer, an antistatic layer, an antifouling layer, etc. on the side opposite to the surface cover plate of the alignment film. In this case, an antireflection layer may be provided on the light source side of the outermost surface cover plate, or may be bonded to another member on the visual viewing side with an adhesive.

The polarizer protective film, the base film, and the shatterproof film can contain various additives as long as the effects of the present invention are not impaired. For example, UV absorbers, inorganic particles, heat-resistant polymer particles, alkali metal compounds, alkaline earth metal compounds, phosphorus compounds, antistatic agents, lightfasteners, flame retardants, heat stabilizers, antioxidants, antigelling agents. , Surfactants and the like. Further, in order to obtain high transparency, it is also preferable that the polyester film contains substantially no particles. "Substantially free of particles" means, for example, in the case of inorganic particles, when the inorganic elements are quantified by Keiko X-ray analysis, the weight is 50 ppm or less, preferably 10 ppm or less, and particularly preferably the detection limit or less. Means quantity.

The alignment film may have various functional layers. Such functional layers include, for example, a hard coat layer, an antiglare layer, an antireflection layer, a low reflection layer, a low reflection antiglare layer, an antireflection antiglare layer, an antistatic layer, a silicone layer, an adhesive layer, and an antifouling layer. One or more selected from the group consisting of a layer, a water-repellent layer, a blue-cut layer, and the like can be used. By providing the antiglare layer, the antireflection layer, the low reflection layer, the low reflection antiglare layer, and / or the antireflection antiglare layer, it can be expected that the color spots when observed from an oblique direction are improved.

When providing various functional layers, it is preferable to have an easy-adhesion layer on the surface of the alignment film. At that time, from the viewpoint of suppressing interference due to reflected light, it is preferable to adjust the refractive index of the easy-adhesion layer so as to be close to the geometric mean of the refractive index of the functional layer and the refractive index of the alignment film. A known method can be adopted for adjusting the refractive index of the easy-adhesion layer, and for example, it can be easily adjusted by adding titanium, zirconium, or other metal species to the binder resin.

(Hard coat layer)
The hard coat layer may be a layer having hardness and transparency, and usually has various curability such as an ionizing radiation curable resin that is typically cured by ultraviolet rays or an electron beam, and a thermosetting resin that is cured by heat. What is formed as a cured resin layer of the resin is used. A thermoplastic resin or the like may be appropriately added to these curable resins in order to appropriately add flexibility and other physical properties. Among the curable resins, the ionizing radiation curable resin is preferable in that a typical and excellent hard coating film can be obtained.

As the ionizing radiation curable resin, a conventionally known resin may be appropriately used. As the ionizing radiation curable resin, radically polymerizable compounds having an ethylenic double bond, cationically polymerizable compounds such as epoxy compounds and the like are typically used, and these compounds are monomers, oligomers, prepolymers and the like. These can be used alone or in combination of two or more as appropriate. Typical compounds are various (meth) acrylate compounds which are radically polymerizable compounds. Among the (meth) acrylate compounds, examples of the compound used at a relatively low molecular weight include polyester (meth) acrylate, polyether (meth) acrylate, acrylic (meth) acrylate, epoxy (meth) acrylate, and urethane (meth). ) Acrylate, etc. can be mentioned.

Examples of the monomer include monofunctional monomers such as ethyl (meth) acrylate, ethylhexyl (meth) acrylate, styrene, methylstyrene, and N-vinylpyrrolidone; or, for example, trimethylpropantri (meth) acrylate and tripropylene glycol di. (Meta) acrylate, diethylene glycol di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, etc. Polyfunctional monomers and the like are also used as appropriate. (Meta) acrylate means acrylate or methacrylate.

When the ionizing radiation curable resin is cured with an electron beam, a photopolymerization initiator is not required, but when it is cured with ultraviolet rays, a known photopolymerization initiator is used. For example, in the case of a radical polymerization system, acetophenones, benzophenones, thioxanthones, benzoins, benzoin methyl ethers and the like can be used alone or in combination as the photopolymerization initiator. In the case of a cationic polymerization system, an aromatic diazonium salt, an aromatic sulfonium salt, an aromatic iodonium salt, a metaserone compound, a benzoin sulfonic acid ester and the like can be used alone or in combination as the photopolymerization initiator.

The thickness of the hard coat layer may be an appropriate thickness, for example, 0.1 to 100 μm, but usually 1 to 30 μm. Further, the hard coat layer can be formed by appropriately adopting various known coating methods.

A thermoplastic resin, a thermosetting resin, or the like can be appropriately added to the ionizing radiation curable resin in order to adjust the physical properties as appropriate. Examples of the thermoplastic resin or the thermosetting resin include acrylic resin, urethane resin, polyester resin and the like.

It is also preferable to add an ultraviolet absorber to the ionizing radiation curable resin in order to impart light resistance to the hard coat layer and prevent discoloration, strength deterioration, crack generation and the like due to ultraviolet rays contained in sunlight and the like. When an ultraviolet absorber is added, the ionizing radiation curable resin is preferably cured by an electron beam in order to prevent the curing of the hard coat layer from being hindered by the ultraviolet absorber. Examples of the ultraviolet absorber include organic ultraviolet absorbers such as benzotriazole compounds and benzophenone compounds, and inorganic ultraviolet absorbers such as fine zinc oxide, titanium oxide and cerium oxide having a particle size of 0.2 μm or less. It may be selected from known substances and used. The amount of the ultraviolet absorber added is about 0.01 to 5% by mass in the ionizing radiation curable resin composition. In order to further improve the light resistance, it is preferable to add a radical scavenger such as a hindered amine radical scavenger in combination with an ultraviolet absorber. The electron beam irradiation has an acceleration voltage of 70 kV to 1 MV and an irradiation dose of about 5 to 100 kGy (0.5 to 10 Mrad).

(Anti-glare layer)
As the antiglare layer, a conventionally known one may be appropriately adopted, and is generally formed as a layer in which an antiglare agent is dispersed in a resin. As the antiglare agent, inorganic or organic fine particles are used. The shape of these fine particles is a true sphere, an ellipse, or the like. The fine particles are preferably transparent. Examples of such fine particles include silica beads as inorganic fine particles and resin beads as organic fine particles. Examples of the resin beads include styrene beads, melamine beads, acrylic beads, acrylic-styrene beads, polycarbonate beads, polyethylene beads, benzoguanamine-formaldehyde beads and the like. The fine particles can be usually added in an amount of 2 to 30 parts by mass, preferably about 10 to 25 parts by mass, based on 100 parts by mass of the resin content.

As with the hard coat layer, the resin that disperses and holds the antiglare agent preferably has as high hardness as possible. Therefore, as the resin, for example, a curable resin such as an ionizing radiation curable resin or a thermosetting resin described in the hard coat layer can be used.

The thickness of the antiglare layer may be an appropriate thickness, and is usually about 1 to 20 μm. The antiglare layer can be formed by appropriately adopting various known coating methods. It is preferable to appropriately add a known anti-precipitation agent such as silica to the coating liquid for forming the anti-glare layer in order to prevent the anti-glare agent from precipitating.

(Anti-reflective layer)
As the antireflection layer, a conventionally known one may be appropriately adopted. In general, the antireflection layer is composed of at least a low refractive index layer, and further, a low refractive index layer and a high refractive index layer (which has a higher refractive index than the low refractive index layer) are alternately laminated adjacent to each other, and the surface side is low-refractive. It consists of a multi-layered layer. The thickness of each of the low-refractive-index layer and the high-refractive-index layer may be appropriately set according to the intended use, and is about 0.1 μm each when adjacently laminated, and about 0.1 μm when the low-refractive index layer alone is used. Is preferable.

As the low refractive index layer, a layer containing a low refractive index substance such as silica or magnesium fluoride in the resin, a layer of a low refractive index resin such as a fluororesin, and a low refractive index substance in the low refractive index resin. A thin film formed by a thin film forming method (for example, a physical or chemical vapor phase growth method such as vapor deposition, sputtering, CVD, etc.) or oxidation of the contained layer or a layer made of a low refractive index substance such as silica or magnesium fluoride. Examples thereof include a film formed by a sol-gel method for forming a silicon oxide gel film from a silicon sol solution, and a layer in which void-containing fine particles are contained in a resin as a low refractive index substance.

The void-containing fine particles are fine particles containing a gas inside, fine particles having a porous structure containing a gas, and the like. It means fine particles with an apparently reduced refractive index. Examples of such void-containing fine particles include silica fine particles disclosed in JP-A-2001-233611. In addition to inorganic substances such as silica, the void-containing fine particles include hollow polymer fine particles disclosed in JP-A-2002-805031 and the like. The particle size of the void-containing fine particles is, for example, about 5 to 300 nm.

Examples of the high refractive index layer include a layer containing a high refractive index substance such as titanium oxide, zirconium oxide, and zinc oxide in the resin, a layer of a high refractive index resin such as a fluorine-free resin, and a high refractive index substance. A layer contained in a rate resin and a layer made of a high refractive index substance such as titanium oxide, zirconium oxide, zinc oxide, etc. are formed by a thin film forming method (for example, physical or chemical vapor phase growth such as vapor deposition, sputtering, CVD, etc.). The thin film formed by the method) can be mentioned.

(Antistatic layer)
As the antistatic layer, a conventionally known one may be appropriately adopted, and is generally formed as a layer containing an antistatic layer in a resin. As the antistatic layer, an organic compound or an inorganic compound is used. For example, examples of the antistatic layer of the organic compound include a cationic antistatic agent, an anionic antistatic agent, an amphoteric antistatic agent, a nonionic antistatic agent, an organic metal antistatic agent, and the like. The inhibitor is used not only as a low molecular weight compound but also as a high molecular weight compound. Further, as the antistatic agent, a conductive polymer such as polythiophene or polyaniline is also used. Further, as an antistatic agent, for example, conductive fine particles made of a metal oxide or the like are also used. The particle size of the conductive fine particles is, for example, about 0.1 nm to 0.1 μm on average in terms of transparency. Examples of the metal oxide include ZnO, CeO ₂ , Sb ₂ O ₂ , SnO ₂ , ITO (indium-doped tin oxide), In ₂ O ₃ , Al ₂ O ₃ , ATO (antimon-doped tin oxide), and the like. AZO (aluminum-doped zinc oxide) and the like can be mentioned.

As the resin containing the antistatic layer, for example, a curable resin such as an ionizing radiation curable resin or a thermosetting resin as described in the hard coat layer is used, and an antistatic layer is used as an intermediate. When the antistatic layer itself is formed as a layer and the surface strength of the antistatic layer itself is not required, a thermoplastic resin or the like is also used. The thickness of the antistatic layer may be appropriately adjusted, and is usually about 0.01 to 5 μm. The antistatic layer can be formed by appropriately adopting various known coating methods.

When the alignment film is used as a polarizer protective film, it is preferable to laminate an antistatic layer on the surface layer thereof. When laminating the antistatic layer, it is preferable to stack the antistatic layer and the antiglare layer on top of each other, or to add an antistatic agent to the antistatic layer and laminate a layer having both layers. When assembling the image display device, the polarizing plate protective film (unlike the polarizing element protective film) is not finally incorporated into the liquid crystal display device as a process member on the surface of the polarizing plate, and is in the middle of the manufacturing process of the liquid crystal display device. (Members discarded in the above) are usually used, but it is preferable to provide an antistatic layer on the side where the polarizing plate protective film is in contact with the polarizing plate or on the opposite side.

(Anti-fouling layer)
As the antifouling layer, a conventionally known one may be appropriately adopted, and generally, a silicon-based compound such as silicone oil or silicone resin; a fluorine-based compound such as a fluorine-based surfactant or a fluorine-based resin is contained in the resin. It can be formed by a known coating method using a paint containing an antifouling agent such as wax. The thickness of the antifouling layer may be appropriately set, and is usually about 1 to 10 μm.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited by the following Examples, and is carried out with appropriate modifications to the extent that it can be adapted to the gist of the present invention. It is also possible, all of which are within the technical scope of the invention.

Evaluation of Rainbow Spots In an image display device having the following configurations 1 and 2, a polarizing film was arranged on the viewing side surface so as to be parallel to the viewing side surface, and a white image was displayed on the screen. While maintaining the parallel state, the white image is viewed while rotating the angle formed by the polarization axis of the polarizing film and the polarization axis of the polarizing element on the visual side of the image display device by 360 degrees to confirm the presence or absence and degree of rainbow spots. , Evaluated according to the following criteria.

<Evaluation criteria>
⊚: No rainbow spots are observed when observed from the front or diagonally, and visibility is good. ○: No rainbow spots are observed when observed from the front, but thin when observed from an angle. Although rainbow spots were observed, visibility was obtained without any practical problems.
X: Iridescent spots are observed whether observed from the front or from an angle.

<Configuration 1 of image display device>
(1) Image display cell: Organic EL cell (2) Visualizing side polarizing plate: Polarized light to which a TAC film (manufactured by Fuji Film Co., Ltd., thickness 80 μm) is bonded as a protective film on both sides of a polarizing element composed of PVA and iodine. A polarizing plate in which a 1/4 wave plate is attached to the image display cell side of the plate.
(3) Visible side shatterproof film: The following oriented films 1 to 5
The shatterproof film was attached to a glass plate via OCA (Optical Clear Adhesive), and an image display device was assembled so that the shatterproof film was on the image display cell side.

<Configuration 2 of image display device>
(1) Backlight light source: White LED or cold cathode tube (2) Light source side polarizing plate: A TAC film is provided as a protective film on both sides of a polarizer composed of PVA and iodine.
(3) Image display cell: Liquid crystal cell (4) Visualizing side polarizing plate: A polarizing plate to which a TAC film (manufactured by Fuji Film Co., Ltd., thickness 80 μm) is bonded as a protective film on both sides of a polarizer composed of PVA and iodine. 5) Light source side shatterproof film: bottom-aligned films 1-5
(6) Touch panel: A resistance film type touch panel having a structure in which a transparent conductive film formed by providing a transparent conductive layer made of ITO on a glass base material is arranged via a spacer.

Production example-PET (A)
When the temperature of the esterification reaction can was raised to 200 ° C., 86.4 parts by mass of terephthalic acid and 64.6 parts by mass of ethylene glycol were charged, and 0.017 parts by mass of antimony trioxide was used as a catalyst while stirring. 0.064 parts by mass of magnesium acetate tetrahydrate and 0.16 parts by mass of triethylamine were charged. Then, the pressure was raised and the pressure esterification reaction was carried out under the conditions of a gauge pressure of 0.34 MPa and 240 ° C., the esterification reaction can was returned to normal pressure, and 0.014 parts by mass of phosphoric acid was added. Further, the temperature was raised to 260 ° C. over 15 minutes, and 0.012 parts by mass of trimethyl phosphate was added. Then, after 15 minutes, dispersion treatment was carried out with a high-pressure disperser, and after 15 minutes, the obtained esterification reaction product was transferred to a polycondensation reaction can, and a polycondensation reaction was carried out under reduced pressure at 280 ° C.

After completion of the polycondensation reaction, filtration is performed with a filter made by Naslon (registered trademark) having a 95% cut diameter of 5 μm, extruded into a strand shape from a nozzle, and using cooling water that has been previously filtered (pore diameter: 1 μm or less). It was cooled, solidified, and cut into pellets. The intrinsic viscosity of the obtained polyethylene terephthalate resin (A) was 0.62 dl / g, and it contained substantially no inert particles and internally precipitated particles. (Hereafter, it is abbreviated as PET (A).)

Orientation film 1
The PET (A) resin pellets containing no particles were dried under reduced pressure (1 Torr) at 135 ° C. for 6 hours, then supplied to an extruder and dissolved at 285 ° C. This polymer is filtered through a stainless sintered filter medium (nominal filtration accuracy of 10 μm particles 95% cut), extruded into a sheet from the base, and then cast into a casting drum with a surface temperature of 30 ° C. using an electrostatic application casting method. It was wound and cooled and solidified to make an unstretched film.

The unstretched film was guided to a tenter stretching machine, and while gripping the end of the film with a clip, it was guided to a hot air zone having a temperature of 125 ° C. and stretched 4.0 times in the width direction. Next, while maintaining the width stretched in the width direction, the film was treated at a temperature of 225 ° C. for 30 seconds, and further subjected to a relaxation treatment of 3% in the width direction to obtain a uniaxially oriented oriented film 1 having a film thickness of about 50 μm. rice field. The Re of the alignment film 1 was 5177 nm, the Rth was 6602 nm, and the Re / Rth was 0.784.

Orientation film 2
By changing the thickness of the unstretched film, a uniaxially oriented oriented film 2 was obtained in the same manner as the oriented film 1 except that the film thickness was set to about 100 μm. The Re of the alignment film 2 was 10200 nm, the Rth was 13233 nm, and the Re / Rth was 0.771.

Orientation film 3
The unstretched film is heated to 105 ° C. using a heated roll group and an infrared heater, then stretched 1.5 times in the traveling direction by the roll group having a peripheral speed difference, and then stretched 1.5 times in the traveling direction, and then in the same manner as in the alignment film 1. A biaxially oriented oriented film 3 having a film thickness of about 50 μm was obtained in the same manner as the oriented film 1 except that the film was stretched 4.0 times in the width direction. The Re of the alignment film 3 was 3915 nm, the Rth was 6965 nm, and the Re / Rth was 0.562.

Orientation film 4
A biaxially oriented oriented film 4 having a film thickness of about 38 μm was obtained in the same manner as the oriented film 3 except that the film was stretched 3.6 times in the traveling direction and 4.0 times in the width direction. The Re of the orientation film 4 was 1178 nm, the Rth was 6365 nm, and the Re / Rth was 0.185.

Orientation film 5
By changing the thickness of the unstretched film, a uniaxially oriented oriented film 5 was obtained in the same manner as the oriented film 1 except that the film thickness was set to about 200 μm. The Re of the alignment film 5 was 20500 nm.

The retardation (Re) and the thickness direction retardation (Rth) were measured as follows. That is, the orientation spindle direction of the film was determined using two polarizing plates, and a rectangle of 4 cm × 2 cm was cut out so that the orientation spindle directions were orthogonal to each other, and used as a measurement sample. For this sample, the refractive indexes (Nx, Ny) of the two axes orthogonal to each other and the refractive index (Nz) in the thickness direction were determined by an Abbe refractive index meter (NAR-4T manufactured by Atago Co., Ltd.), and the refractive indexes of the two axes were obtained. The absolute value of the difference (| Nx-Ny |) was determined as the anisotropy of the refractive index (ΔNxy). The film thickness d (nm) was measured using an electric micrometer (Millitron 1245D, manufactured by Finereuf), and the unit was converted to nm. The retardation (Re) was determined from the product (ΔNxy × d) of the anisotropy of the refractive index (ΔNxy) and the thickness d (nm) of the film. Further, Nx, Ny, Nz and the film thickness d (nm) are obtained by the same method as the measurement of retardation, and the average value of (ΔNxz × d) and (ΔNyz × d) is calculated to perform thickness direction retardation (ΔNyz × d). Rth) was calculated.

The evaluation results are shown in Table 1 below.

As shown in Table 1 above, by providing an alignment film having a retardation of 3000 nm or more on the viewing side of the polarizing element on the viewing side, an organic EL cell and a liquid crystal cell (excluding the case where the light source is a cold cathode tube) are provided as image display cells. It was confirmed that the occurrence of iridescent spots was suppressed when any of) was used.

E1 Organic EL display device E4 Organic EL cell E5 Visualizing side polarizing plate E6 Touch panel E7 Light source side polarizing element E8 Visualizing side polarizing element E9a Polarizer protective film E9b Polarizer protective film E10a Polarizer protective film E10b Visualizing side polarizing element protective film E11 Light source Side transparent conductive film E11a Light source side base film E11b Transparent conductive layer E12 Visible side transparent conductive film E12a Visible side base film E12b Transparent conductive layer E13 Spacer E14 Light source side shatterproof film E15 Visible side shatterproof film E16 1/4 Wavelength plate L1 Liquid crystal display device L2 Light source L3 Light source side polarizing plate L4 Liquid crystal cell L5 Visualizing side polarizing plate L6 Touch panel L7 Light source side polarizer L8 Visualizing side polarizer L9a Polarizer protective film L9b Polarizer protective film L10a Polarizer protective film L10b Visual recognition Side polarizer protective film L11 Light source side transparent conductive film L11a Light source side base film L11b Transparent conductive layer L12 Visible side transparent conductive film L12a Visible side base film L12b Transparent conductive layer L13 Spacer L14 Light source side shatterproof film L15 Visible side Anti-scattering film E17 Substrate E18 Polarized light E19 Organic light emitting layer E20 Polarized light

Claims (1)

(1) Organic EL cell,
It has an alignment film having (2) a polarizing plate arranged on the visible side of the organic EL cell and (3) an alignment film having in-plane retardation of 6000 nm or more and 150,000 nm or less arranged on the visible side of the polarizing plate. An organic EL display device in which the ratio (Re / Rth) of the in-plane retardation of the alignment film to the retardation in the thickness direction is 0.771 or more and 1.0 or less.

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