TWI722324B - Organic EL display device - Google Patents

Abstract

The purpose is to provide an image display device with improved visibility.

An image display device having: (1) an organic EL unit; (2) a polarizer arranged on the viewing side of the organic EL unit; and (3) a polarizer arranged on the viewing side of the polarizer with a wavelength of 3000nm or more and 150,000nm The following hysteresis alignment film.

Description

Organic EL display device

The present invention relates to an image display device.

Image display devices are widely used in mobile phones, tablet terminals, personal computers, TVs, PDAs, electronic dictionaries, navigation devices, music players, digital cameras, and digital cameras. With the progress of the miniaturization and weight reduction of image display devices, its use is not limited to offices or indoors, but also extends to outdoor use in mobile applications such as cars or trams.

In this way, the chance of viewing the image display device through a polarizing filter such as sunglasses has increased. On the other hand, for image display devices, the use of alignment films has been proposed for various reasons. However, when an alignment film is used in an image display device, the deflection characteristics of the light emitted from the polarizing plate are distorted due to its birefringence. As a result, when viewing an image with a polarizing filter, the color tones such as rainbow spots may be distorted. Clutter leads to the problem of deterioration of visibility (Patent Document 1).

Prior art literature Patent literature

Patent Document 1 WO2011/058774

Therefore, an object of the present invention is to improve the visibility when viewing an image display device using an alignment film through a polarizing filter.

The inventors of the present invention have repeatedly studied day and night to solve the above-mentioned problems and found that the above-mentioned problems can be solved by controlling the hysteresis of the alignment film. The inventors of the present invention have further repeated many studies and improvements based on the above findings, and finally completed the present invention.

The representative invention is as follows:

Item 1.

An image display device having: (1) an image display unit; (2) a polarizer arranged on the viewing side of the image display unit; and (3) a polarizer arranged on the viewing side of the polarizer with a diameter of 3000nm or more and 150,000nm The following hysteresis alignment film.

Item 2.

The image display device of item 1, wherein the angle between the polarization axis of the polarizer and the alignment main axis of the alignment film is approximately 45 degrees.

Item 3.

The image display device of item 1 or 2, wherein the image display unit is an organic EL unit.

According to the present invention, the visibility of the image display device is improved. In particular, the deterioration of the image quality caused by the clutter of the color tone represented by the rainbow spot that occurs when viewed through the polarizing filter is reduced. Moreover, in this manual, "rainbow spot" is a concept including "color unevenness", "color shift" and "interference color".

E1‧‧‧Organic EL display device

E4‧‧‧Organic EL Unit

E5‧‧‧Visibility side polarizer

E6‧‧‧Touch Panel

E7‧‧‧Light source side polarizer

E8‧‧‧Visibility side polarizer

E9a‧‧‧Polarizer protective film

E9b‧‧‧Polarizer protective film

E10a‧‧‧Polarizer protective film

E10b‧‧‧Visibility side polarizer protective film

E11‧‧‧Transparent conductive film on the light source side

E11a‧‧‧Light source side substrate film

E11b‧‧‧Transparent conductive layer

E12‧‧‧Visible side transparent conductive film

E12a‧‧‧Visibility side substrate film

E12b‧‧‧Transparent conductive layer

E13‧‧‧Spacer

E14‧‧‧Anti-scattering film on the light source side

E15‧‧‧Visibility side anti-scattering film

E16‧‧‧1/4 wavelength plate

L1‧‧‧LCD device

L2‧‧‧Light source

L3‧‧‧Light source side polarizing plate

L4‧‧‧LCD unit

L5‧‧‧Visibility side polarizer

L6‧‧‧Touch Panel

L7‧‧‧Light source side polarizer

L8‧‧‧Visibility side polarizer

L9a‧‧‧ Polarizer protective film

L9b‧‧‧Polarizer protective film

L10a‧‧‧Polarizer protective film

L10b‧‧‧Visibility side polarizer protective film

L11‧‧‧Transparent conductive film on the light source side

L11a‧‧‧Light source side substrate film

L11b‧‧‧Transparent conductive layer

L12‧‧‧Visible side transparent conductive film

L12a‧‧‧Visibility side substrate film

L12b‧‧‧Transparent conductive layer

L13‧‧‧Spacer

L14‧‧‧Light source side anti-scattering film

L15‧‧‧Visibility side anti-scattering film

E17‧‧‧Substrate

E18‧‧‧Anode

E19‧‧‧Organic light-emitting layer

E20‧‧‧Cathode

Fig. 1 is a schematic cross-sectional view showing a representative organic EL display device.

Fig. 2 is a schematic cross-sectional view showing a representative liquid crystal display device.

Fig. 3 is a schematic cross-sectional view showing a representative organic EL unit.

[The form of implementing the invention]

The image display device typically has an image display unit and a polarizing plate. The image display unit typically uses an organic EL unit or a liquid crystal unit. A representative schematic diagram of an image display device (organic EL display device) using an organic EL unit as the image display unit is shown in Figure 1, and a representative schematic diagram of an image display device (liquid crystal display device) using a liquid crystal cell as the image display unit The figure is shown in Figure 2. Hereinafter, the representative structure of the image display device is described with reference to FIG. 1 or FIG. 2. However, the structure of the image display device is not limited to these, and various changes are possible.

In this manual, the side on which the image is displayed on the image display device (the side on which we view the image) is referred to as the "visual recognition side", and the opposite side of the visual recognition side (that is, in the organic EL display device, there is The side of the organic EL unit that also functions as a light source; in a liquid crystal display device, the side where the light source is arranged) is called the "light source side". In Figures 1 and 2, the right side is the visible side, and the left side is the light source side.

As shown in Figure 1, the organic EL display device (E1) may have: an organic EL unit (E4), a polarizing plate (E5), and a touch panel (E6). A quarter-wavelength plate (E16) can be provided between the organic EL unit (E4) and the polarizing plate (E5). The polarizer (E5) is typically installed on the visible side of the organic EL unit (E4), and has a structure in which polarizer protective films (E10a, E10b) are laminated on both sides of a film called "polarizer (E8)". The touch panel (E6) is typically located on the viewing side of the viewing side polarizer (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 visible side of the touch panel (E6), a transparent base anti-scattering film (E14, E15) can be provided via any adhesive layer.

As shown in Figure 2, the liquid crystal display device (L1) may have: a light source (L2), a liquid crystal cell (L4), and a touch panel (L6). Polarizing plates (light source side polarizing plate (L3) and visibility side polarizing plate (L5)) are typically provided on both the light source side and the visible side of the liquid crystal cell (L4). Each polarizer (L3, L5) typically has a structure in which polarizer protective films (L9a, L9b, L10a, L10b) are laminated on both sides of a film called "polarizers (L7, L8)". In this specification, the polarizing plate (L5) that is located closer to the viewing side than the image display unit is called the "visibility side polarizing plate", and the polarizing lens (L8) that constitutes it is also called the "visibility side polarizing lens". The touch panel (L6) is typically located closer to the viewing side than 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 laminated base film (L11a, L12a) and a transparent conductive layer (L11b, L12b) structure. In addition, on the light source side and the visible side of the touch panel (L6), an anti-scattering film (L14, L15) as a transparent substrate can be provided via any adhesive layer.

In addition, in Figures 1 and 2, there are touch panels (E6, L6) shown on the viewing side of the viewing side polarizer (E5, L5), but there is no need for a touch panel, but any film . For example, there may be one anti-scattering film on the viewing side of the viewing side polarizing plate. The touch panel is not limited to the above-mentioned resistive film type touch panel, and other types of touch panels such as projection type electric power type can be used. For example, the transparent conductive film may be one sheet. The anti-scattering film does not necessarily have to be arranged on both sides of the touch panel, and it may be configured to be arranged on either side, or the anti-scattering film may not be arranged on both sides.

<Position of Alignment Film>

In image display devices, alignment films can be used for various purposes. In this specification, the alignment film refers to a polymer film with birefringence. As for the image display device, from the viewpoint of improving visibility, it is preferable to have an alignment film with a hysteresis of 3000 nm to 150,000 nm on the viewing side of the viewing side polarizer closer to the viewing side. In this specification, an alignment film with a hysteresis of 3000 nm or more and 150,000 nm or less is also referred to as a "high hysteresis alignment film." Therefore, in the liquid crystal display devices shown in Figures 1 and 2, the alignment film can typically be used for: Polarizer protective film (E10b, L10b) located closer to the viewing side than the viewing side polarizer (E8, L8) (Hereinafter referred to as "Visibility side polarizer protective film"), the base film (E11a, L11a) of the transparent conductive film (E11, L11) placed on the side of the spacer (E13, L13) closer to the light source (hereinafter referred to as "Light source side base film"), base film (E12a, L12a) of transparent conductive film (E12, L12) located closer to the visible side of the spacer (E13, L13) (hereinafter referred to as "visible side base film" "), the anti-scattering film (E14, L14) (hereinafter referred to as the "light source side anti-scattering film") between the viewing side polarizer protective film (E10b, L10b) and the light source side base film (E11a, L11a) and / Or anti-scattering film (E15, L15) located closer to the visible side than the visible-side base film (E12a, L12a) (hereinafter referred to as "visible side anti-scattering film").

The number of high hysteresis alignment films used in the image display device is arbitrary and is not particularly limited. It is preferable to use at least one high hysteresis alignment film in the above-mentioned position. As a representative example of this type of image display device, the organic EL display device or liquid crystal display device shown in Figure 1 or Figure 2 is provided at a position corresponding to the anti-scattering film (E15, L15) on the visible side Organic EL display device or liquid crystal display device with high hysteresis alignment film. In this representative example, the aforementioned high hysteresis alignment film may have an anti-reflection layer on the surface of the visible side.

As another representative example of the image display device, there is a "surface cover integrated touch panel" with a capacitive touch panel provided on a surface cover of glass, etc., and the "surface cover integrated touch panel" Those who assemble high-hysteresis alignment films on the “panel”. As a specific structure of the "surface cover integrated touch panel", the following forms (A) to (F) can be exemplified.

(A) A transparent conductive layer is provided on the light source side or the visible side of the surface cover, and a high hysteresis alignment film is attached to the surface of the transparent conductive layer or the surface of the surface cover opposite to the transparent conductive layer as the surface of the anti-scattering film Cover integrated touch panel. The transparent conductive layer can be provided on the light source side or the visible side of the surface cover, but is preferably provided on the light source side.

(B) Glue glass plates on both sides of the high-hysteresis alignment film to make laminated glass, and set a transparent conductive layer on the light source side of the laminated glass to integrate a touch panel with a surface cover.

(C) A transparent conductive layer is provided on one side of the high hysteresis film, and it is pasted on the light source side of the surface cover or the surface cover integrated touch panel on the visible side. If it is pasted on the light source side, it can be pasted on either the surface of the high-hysteresis alignment film on the side where the transparent conductive layer is not provided or the surface of the transparent conductive layer. When sticking to the visible side, it is better to stick the surface of the transparent conductive layer and the surface cover.

(D) A transparent conductive layer is provided on both sides of the high hysteresis film, and it is adhered to the surface cover integrated touch panel on the light source side of the surface cover.

It is preferable to provide an anti-reflection layer on the innermost surface (the surface closest to the light source side) of the surface cover integrated touch panel. Moreover, if the innermost surface is a transparent conductive layer, an electrode protective coating can be provided, and an anti-reflection layer can be provided on it. Furthermore, an anti-reflection layer, an anti-glare layer, an anti-static layer, an anti-fouling layer, etc. can be provided on the outermost surface (the surface on the most visible side) of the surface-cover integrated touch panel. Moreover, the bonding of each part is more suitable for the use of baseless optical adhesives.

(E) A surface cover integrated touch panel formed by arranging a transparent conductive layer on one or both sides of a film without birefringence and bonding it with a surface cover and a high hysteresis alignment film. Here, as long as the outermost surface (the surface on the most visible side of the image display device) is a cover plate or a high-hysteresis alignment film, the bonding order is arbitrary.

(F) A surface cover integrated touch panel formed by providing a transparent conductive layer on one or both sides of a sheet such as glass and bonding it with a surface cover and a high-hysteresis alignment film. Here, as long as the outermost surface (the surface on the most visible side of the image display device) is a cover plate or a high-hysteresis alignment film, the other order of bonding is arbitrary.

From the viewpoint of reducing rainbow spots, the lower limit of the hysteresis of the high-hysteresis alignment film is preferably 4500 nm or more, more preferably 6000 nm or more, preferably 8000 nm or more, and preferably 10000 nm or more. On the other hand, as far as the upper limit of the hysteresis of the high-hysteresis alignment film is concerned, the use of a polyester film with higher hysteresis can not substantially achieve further visibility improvement effects, and as the hysteresis increases, the thickness of the alignment film also varies. The upward trend may therefore be contrary to the requirements for thinning; according to this point of view, it is set to 150,000 nm, but theoretically it can be set to a higher value. When the image display device has more than two high-hysteresis alignment films, their hysteresis can be the same or different.

From the viewpoint of suppressing rainbow spots more effectively, the ratio (Re/Rth) of the hysteresis (Re) to the thickness-direction hysteresis (Rth) of the high hysteresis alignment film is preferably 0.2 or more, preferably 0.5 or more, and more preferably 0.6 or more. The thickness direction hysteresis refers to the average value of the hysteresis obtained by multiplying the two birefringences ΔNxz and ΔNyz by the film thickness d when viewed in a cross-section in the thickness direction of the film. The greater the Re/Rth, the more the effect of birefringence increases its isotropy, which can more effectively suppress the occurrence of rainbow spots on the screen. In addition, in this manual, when only described as "hysteresis", it means in-plane hysteresis.

The maximum value of Re/Rth is 2.0 (that is, a completely uniaxially symmetric film), but the closer to a complete uniaxially symmetric film, the mechanical strength in the direction orthogonal to the alignment direction tends to decrease gradually. Therefore, the upper limit of the Re/Rth of the polyester film is preferably 1.2 or less, and more preferably 1.0 or less. Even if the above ratio is 1.0 or less, it can still meet the viewing angle characteristics (180 degrees left and right, 120 degrees up and down) required by the image display device.

The hysteresis of the alignment film can be measured according to well-known methods. Specifically, it can be obtained by measuring the refractive index and thickness in the biaxial direction. In addition, 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 between the alignment main axis of the high hysteresis alignment film and the polarization axis of the viewing side polarizer (assuming that the high hysteresis alignment film and the polarizer are in the same plane) is not particularly limited. Based on the viewpoint of reducing rainbow spots, it is preferably approximately 45 degrees ( Approximately 45 degrees). For example, the aforementioned 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 Degrees ±2 degrees, 45 degrees ±1 degrees, 45 degrees. In this manual, the term "below" means only adding a value after "±". Therefore, for example, the aforementioned "45 degrees ± 20 degrees or less" means that a range of 20 degrees up and down is allowed to vary around 45 degrees.

If the polarizer and the high hysteresis alignment film are arranged in such a way that the polarization axis and the alignment main axis meet a certain angle as described above, for example, the cut high hysteresis alignment film can be arranged such that the alignment main axis and the polarization axis of the polarizer have a specific angle Or the method of diagonally extending the high-hysteresis alignment film.

The alignment main axis of the high-hysteresis alignment film is preferably arranged in the image display device in a manner parallel to the vertical axis or the horizontal axis of the rectangular display screen. The reason is that when the alignment main axis of the high hysteresis alignment film is approximately parallel to the longitudinal axis of the display, when the screen is viewed from an oblique direction (from the lateral direction) instead of from the front, the rainbow spots are suppressed and the visibility is excellent. On the other hand, the reason is that when the alignment main axis of the high hysteresis alignment film is slightly the same as the horizontal direction of the monitor screen, when the screen is viewed from an oblique direction (from the horizontal direction) instead of from the front, the rainbow spots are suppressed and the visibility is excellent. .

The image display device only needs to have at least one high-hysteresis alignment film on the viewing side of the viewing-side polarizer, and it can have an alignment film with a retardation of less than 3000 nm at any position. This kind of oriented film is well known and can be commercialized.

The high-hysteresis alignment film can be manufactured by appropriately selecting well-known methods. For example, the high hysteresis alignment film can be selected from the group consisting of p-polyester resin, polycarbonate resin, polystyrene resin, para-polystyrene resin, polyether ether ketone resin, polyphenylene sulfide resin, cycloolefin resin, Liquid crystal polymer resins and cellulose resins are produced by adding one or more of the group of resins of liquid crystal compounds. Therefore, the high hysteresis alignment film can be a polyester film, a polycarbonate film, a polystyrene film, a para-polystyrene film, a polyether ether ketone film, a polyphenylene sulfide film, a cycloolefin film, and a liquid crystal compound added to the film. Liquid crystalline film, film made of cellulose resin.

The preferred raw material resins for high-hysteresis alignment films are polycarbonate and/or polyester, and para-polystyrene. These resins have excellent transparency, thermal and mechanical properties, and can easily control hysteresis by stretching. Polyester represented by polyethylene terephthalate and polyethylene naphthalate has a large inherent birefringence, and even if the film thickness is thin, it is easier to obtain a large hysteresis, which is preferable. In particular, polyethylene naphthalate has a relatively large inherent complex refractive index in polyester, and therefore it is suitable when the hysteresis is to be increased, or the film thickness is to be reduced while maintaining high hysteresis. Taking polyester resin as a representative example, a more specific method of manufacturing a high-hysteresis alignment film will be described later.

The alignment film with a hysteresis of less than 3000 nm can be manufactured by appropriately selecting well-known methods. For example, it can be selected from polyester resins, acetate resins, polyether resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins (polyethylene resins, polypropylene resins, Cyclic polyolefins, etc.), (meth)acrylic resins, polyvinyl chloride resins, polyvinylidene chloride resins, polystyrene resins, polyvinyl alcohol resins, polyarylate resins, polyphenylene sulfide resins, and cellulose acetate Resin (cellulose triacetate, etc.) and other resins in the group are obtained as raw materials. Among these, polyester resins and polyolefin resins are preferred, polyester resins are more preferred, and polyethylene terephthalate and/or polypropylene resins are still more preferred.

<Manufacturing Method of Alignment Film>

Hereinafter, a polyester film is taken as an example to describe a method of manufacturing an alignment film including a high hysteresis alignment film. The polyester film can be obtained by condensation of any dicarboxylic acid and diol. As the dicarboxylic acid, for example, terephthalic acid, isophthalic acid, phthalic acid, 2,5-naphthalene diacid, 2,6-naphthalene diacid, 1,4-naphthalene diacid, 1,5 -Naphthalic acid, diphenyl carboxylic acid, diphenoxy succinic acid, diphenyl carboxylic acid, anthracene acid, 1,3-cycloglutaric acid, 1,3-cyclohexanedioic acid, 1,4 -Cycloadipic acid, hexahydroterephthalic acid, hexahydroisophthalic acid, malonic acid, dimethylmalonic acid, succinic acid, 3,3-diethylsuccinic acid, glutaric acid, 2,2-Dimethylglutaric acid, adipic acid, 2-methyladipic acid, trimethyladipic acid, pimelic acid, azelaic acid, dimer acid, sebacic acid, suberic acid, Dodecanedioic acid and so on.

As the glycol, for example, ethylene glycol, propylene glycol, hexamethylene glycol, neopentyl glycol, 1,2-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, decamethylene glycol, 1, 3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 2,2-bis(4-hydroxyphenyl)propane, bis(4-hydroxyphenyl)碸 etc.

The dicarboxylic acid component and the diol component constituting the polyester film can be used individually by one type or two or more types. As the specific polyester resin constituting the polyester film, for example, polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, etc. , Preferably polyethylene terephthalate and polyethylene naphthalate, more preferably polyethylene terephthalate. The polyester resin may also contain other copolymerization components. From the viewpoint of mechanical strength, the ratio of the copolymerization components is preferably 3 mol% or less, more preferably 2 mol% or less, and still more preferably 1.5 mol% or less. These resins are excellent in transparency, and also excellent in thermal and mechanical properties. In addition, these resins can easily control the hysteresis by extension processing.

Polyester film can be obtained by following general manufacturing methods. Specifically, an unaligned polyester formed by melting a polyester resin and extruding into a sheet shape can be stretched in the longitudinal direction at a temperature higher than the glass transition temperature using the speed difference of the rollers, and then drawn The web is stretched in the transverse direction and is heat-treated to form an aligned polyester film. The polyester film may be a uniaxially stretched film or a biaxially stretched film. The high-hysteresis alignment film can also be formed by extending 45 degrees obliquely.

The manufacturing conditions for preparing the polyester film can be appropriately set in accordance with well-known methods. For example, the vertical stretching temperature and the horizontal stretching temperature are usually 80 to 130°C, preferably 90 to 120°C. The longitudinal stretching magnification is usually 1.0 to 3.5 times, preferably 1.0 to 3.0 times. The transverse stretch magnification is usually 2.5 to 6.0 times, preferably 3.0 to 5.5 times.

The hysteresis can be controlled within a specific range by appropriately setting the stretching ratio, stretching temperature, and film thickness. For example, the higher the stretching ratio difference between the vertical stretching and the horizontal stretching, the lower the stretching temperature, and the thicker the film thickness, the easier it is to obtain high hysteresis. Conversely, the lower the stretching ratio difference between the vertical stretching and the horizontal stretching, the higher the stretching temperature, and the thinner the film thickness, the easier it is to obtain low hysteresis. Furthermore, the higher the stretching temperature and the lower the total stretching ratio, the easier it is to obtain a film with a lower ratio of hysteresis to thickness-direction hysteresis (Re/Rth). Conversely, the lower the extension temperature and the higher the total extension ratio, the easier it is to obtain a film with a higher ratio of hysteresis to thickness direction hysteresis (Re/Rth). Furthermore, the heat treatment temperature is generally preferably 140 to 240°C, preferably 180 to 240°C.

In order to suppress the hysteresis of the polyester film, the thickness unevenness of the film should be as small as possible. When the longitudinal stretching magnification is lowered in order to provide a hysteresis difference, the value of longitudinal thickness unevenness may increase. The value of longitudinal thickness unevenness has a sharply rising area within a certain range of stretching magnification. Therefore, it is ideal to set the film forming conditions in a way that avoids this range.

The thickness unevenness of the aligned polyester film is preferably 5.0% or less, more preferably 4.5% or less, still more preferably 4.0% or less, and particularly preferably 3.0% or less. The thickness unevenness of the film can be measured by any means. For example, a strip sample (length 3m) that is continuous in the film flow direction is sampled, and a commercially available measuring device (such as the electronic micrometer Millitron 1240 manufactured by Seiko-EM Co., Ltd.) is used to measure 100 at a distance of 1 cm. For the thickness of the point, obtain the maximum value (dmax), minimum value (dmin), and average value (d) of the thickness, and calculate the thickness unevenness (%) by the following formula.

Thickness unevenness (%)=((dmax-dmin)/d)×100

<Image display unit and light source>

In the image display device, the light emitted from the image display unit preferably has a continuous and wide emission spectrum based on the viewpoint of suppressing rainbow spots. Here, "continuous and wide emission spectrum" refers to the emission spectrum in the wavelength region of at least 450 to 650 nm, preferably in the visible light region where there is no wavelength region where the light intensity is zero. The visible light region is, for example, a wavelength region of 400 to 760 nm, which can be 360 to 760 nm, 400 to 830 nm, or 360 to 830 nm.

When the image display device has an organic EL unit as the image display unit, the organic EL unit itself has a function as a light source with a continuous and wide emission spectrum. On the other hand, when the image display device has a liquid crystal cell as the image display unit, it is better to have a light source with a continuous and wide emission spectrum.

The method and structure of the light source with continuous and wide emission spectrum are not particularly limited, and may be, for example, an edge emitting method or a direct type method. As such a white light source, for example, a white light-emitting diode (white LED) can be cited. The white LED can be exemplified by the phosphor method (that is, a light emitting diode that emits blue light and ultraviolet light using compound semiconductors and a phosphor combined to emit white light) and organic light emitting diodes (Organic light -emitting diode: OLED) and so on. Based on the viewpoint that it has a continuous and wide emission spectrum and excellent luminous efficiency, it is preferable to include a white light emitting element composed of a blue light emitting diode using a compound semiconductor and a yttrium aluminum garnet-based yellow phosphor. Diode.

The organic EL unit can be appropriately selected and used as an organic EL unit well-known in the technical field. The use of organic EL units is better in terms of wide viewing angle, high contrast ratio and high-speed response. A schematic cross-sectional view of a representative organic EL unit is shown in FIG. 3. The organic EL unit (E4) typically has an anode (E18), an organic light-emitting layer (E19), and a cathode (E20) that are metal electrodes stacked on a transparent substrate (E17) in order from the visible side. Structured emitters (organic electroluminescent emitters). In the organic EL cell, when a voltage is applied between the anode and the cathode, holes injected from the anode and electrons injected from the cathode are recombined in the organic light-emitting layer to emit light.

As the aforementioned transparent substrate, any transparent substrate can be used. For example, the transparent substrate can be selected from the group consisting of glass substrates, ceramic substrates, semiconductor substrates, metal substrates, and plastic substrates. As a specific plastic substrate, a transparent resin film that has been used as a base film for a touch panel, which will be described later, can be mentioned. The transparent substrate can also be provided with a surface treatment layer as required. As the surface treatment layer, for example, a moisture-permeable layer, a gas barrier layer, a hard coat layer, an undercoat layer, etc. may be mentioned.

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

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

The organic light-emitting layer has the function of providing a field of recombination of holes and electrons when a voltage is applied to make it emit light. The organic light-emitting layer contains an organic light-emitting material, and may have a single-layer structure or a stacked-layer structure of two or more layers. In the case of a multilayer structure, each layer can emit light in different luminous colors. The thickness of the above-mentioned 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 in the organic light-emitting layer can be appropriately selected from any light-emitting materials. Specifically, it may contain olefin-based luminescent materials such as 4,4'-(2,2-diphenylvinyl)biphenyl; 9,10-bis(2-naphthyl)anthracene, 9,10-bis(3 ,5-Diphenylphenyl)anthracene, 9,10-bis(9,9-dimethylsulfonyl)anthracene, 9,10-(4-(2,2-diphenylvinyl)phenyl) Anthracene, 9,10'-bis(2-biphenyl)-9,9'-bianthracene, 9,10,9',10'-tetraphenyl-2,2'-bianthracene, 1,4- Anthracene-based luminescent materials such as bis(9-phenyl-10-anthracene)benzene; 2,7,2',7'-four (2,2-diphenylvinyl) spiro-linked luminescent materials; 4 ,4'-dicarbazole biphenyl, 1,3-dicarbazolyl benzene and other carbazole-based luminescent materials; 1,3,5-trinucleotide benzene and other pyrene-based luminescent materials are appropriately selected from the group.

The organic EL unit may be provided with a sealing member formed by covering the organic EL element in order to block the organic EL element composed of the anode, the organic light-emitting layer, and the cathode on the above-mentioned base material from the influence of the atmosphere. With the sealing member, it is possible to prevent moisture and oxygen in the atmosphere from deteriorating the light-emitting characteristics of the organic light-emitting layer.

The organic EL element may further include any member (for example, a hole injection layer, a hole transport layer, an electron injection layer, and/or an electron transport layer) at any appropriate position.

If an organic EL unit is used as the image display unit, generally speaking, the polarizing plate in the image display device is not necessary. However, since the thickness of the organic light-emitting layer is about 10 nm and extremely thin, when external light is reflected by the metal electrode and then emitted to the viewing side, and viewed from the outside, the display surface of the organic EL display device sometimes looks like a mirror surface. In order to shield the specular reflection of external light, it is better to install a polarizing plate on the visible side of the organic EL unit, and further install a quarter-wavelength plate between the organic EL unit and the aforementioned polarizing plate. The circular polarizing plate is formed by the combination of the viewing side polarizer and the quarter-wavelength plate, and the external light reflected by the metal electrode in the organic EL unit is shielded by the circular polarizing plate, thereby suppressing the visibility of the image display device decline.

Any liquid crystal cell that can be used in a liquid crystal display device can be appropriately selected and used as the liquid crystal cell, and its mode or structure is not particularly limited. For example, a liquid crystal cell of VA mode, IPS mode, TN mode, STN mode, or bend alignment (π-type) can be appropriately selected and used. Therefore, the liquid crystal cell can appropriately select and use liquid crystals made of well-known liquid crystal materials and liquid crystal materials that can be developed in the future. In one embodiment, the preferred liquid crystal cell is a transmissive liquid crystal cell.

<Polarizer and Polarizer Protective Film>

The polarizing plate has a structure in which two protective films (referred to as "polarizer protective film") sandwich both sides of the film-shaped polarizer. As the polarizer, any polarizer (or polarizing film) used in this technical field can be appropriately selected and used. As a representative polarizer, a polyvinyl alcohol (PVA) film or the like is dyed with a dichroic material such as iodine, but it is not limited to this, and a known polarizer that can be developed in the future can be appropriately selected and used.

Commercially available PVA films can be used, such as "Kuraray Vinylon (manufactured by Kuraray Co., Ltd.)", "Tohcello Vinylon (manufactured by Tohcello Co., Ltd.)", "Nichigo Vinylon (manufactured by Nippon Synthetic Chemical Co., Ltd.)" and the like. Examples of dichroic materials include iodine, diazonium compounds, and polymethine dyes.

The polarizer can be obtained by any method, for example, it can be obtained by dyeing the PVA film with a dichroic material, performing uniaxial stretching in an aqueous boric acid solution, and washing and drying while maintaining the extended state. The stretching magnification of uniaxial stretching is usually about 4 to 8 times, and is not particularly limited. Other manufacturing conditions can be appropriately set based on well-known methods.

The protective film on the viewing side of the viewing side polarizer (the viewing side polarizer protective film) may be a high hysteresis alignment film, or any film that has been used as a protective film for the polarizing lens, and is not limited to these.

The types of the protective film on the light source side of the viewing side polarizer and the protective film on the light source side polarizer are arbitrary, and the film that has been used as a protective film can be appropriately selected and used. From the viewpoints of handling and ease of handling, it is preferable to use, for example, a film selected from the group consisting of triacetate cellulose (TAC) film, acrylic film, and cyclic olefin film (such as norbornene film), polypropylene film, and poly One or more non-birefringent films in the group of olefin-based films (such as TPX).

In one embodiment, the light source side protective film of the visual recognition side polarizer and the visual recognition side protective film of the light source side polarizer are preferably optical compensation films with optical compensation functions. Such an optical compensation film can be appropriately selected according to the various modes of the image display unit, for example, a liquid crystal compound (such as a discotic liquid crystal compound and/or a birefringent compound) dispersed in cellulose triacetate may be selected. Resins, cyclic olefin resins (such as norbornene resins), propionyl acetate resins, polycarbonate film resins, acrylic resins, styrene acrylonitrile copolymer resins, lactone ring-containing resins, and phenolic resins One or more of the group of imino-based polyolefin resins.

Since the optical compensation film can be obtained commercially, it can be appropriately selected and used. Examples include "Wide View-EA" and "Wide View-T" (manufactured by FUJIFILM) for the TN method, "Wide View-B" (manufactured by FUJIFILM) for the VA method, and VA-TAC (manufactured by KONICA MINOLTA) ), "ZEONOR FILM" (manufactured by ZEON Corporation in Japan), "ARTON" (manufactured by JSR Corporation), "X-plate" (manufactured by Nitto Denko Corporation), and "Z-TAC" (manufactured by FUJIFILM Corporation) for the IPS method, "CIG" (manufactured by Nitto Denko Corporation), "P-TAC" (manufactured by Okura Industrial Co., Ltd.), etc.

The polarizer protective film can be laminated on the polarizer directly or through 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 one can be used. From the viewpoint of making the adhesive layer thinner, an aqueous product (that is, one that dissolves or disperses the adhesive component in water) is preferred. For example, when polyester film is used as a polarizer protective film, polyvinyl alcohol-based resin and urethane resin are used as the main components, and to improve adhesion, isocyanate-based compounds and epoxy compounds can be used as required. Etc. as an adhesive. The thickness of the adhesive layer is preferably 10 μm or less, more preferably 5 μm or less, and still more preferably 3 μm or less.

If TAC film is used as a protective film for polarizers, polyvinyl alcohol-based adhesives can be used for bonding. As the polarizer protective film, when an acrylic film, a cyclic olefin-based film, a polypropylene film, or a film with low moisture permeability such as TPX is used, 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, for example, it can be set appropriately within the range of 15-300 μm, preferably within the range of 30-200 μm.

<Touch panel, transparent conductive film, base film, anti-scattering film>

The image display device may have a touch panel. The type and method of the touch panel are not particularly limited, and examples include resistive film touch panels and capacitive touch panels. The touch panel has nothing to do with this method, and generally has one or more transparent conductive films. 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-hysteresis alignment film, other films conventionally used as base films, or rigid plates such as glass plates can be used.

As other films conventionally used as base films, various resin films having transparency can be cited. It can be used, for example, selected from the group consisting of polyester resins, acetate resins, polyether ether resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, (meth)acrylic resins, and polychlorinated resins. A film made of one or more resins from the group of vinyl resin, polyvinylidene chloride resin, polystyrene resin, polyvinyl alcohol resin, polyarylate resin, and polyphenylene sulfide resin. Among these, polyester resins, polycarbonate resins, and polyolefin resins are preferred, and polyester resins are preferred.

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

The surface of the substrate film can be pre-treated with etching treatment or primer treatment such as sputtering, corona discharge, flame, ultraviolet irradiation, electron beam irradiation, chemical conversion, and oxidation. Thereby, the adhesiveness with the transparent conductive layer etc. provided on the base film can be improved. Furthermore, before providing the transparent conductive layer, etc., the surface of the substrate film can be cleaned and cleaned by solvent cleaning or ultrasonic cleaning.

The transparent conductive layer can be laminated directly on the substrate film, but can be laminated through the easy-adhesive layer and/or various other laminated layers. Examples of other layers include a hard coat layer, an index matching (IM) layer, and a low refractive index layer. The typical laminated structure of the transparent conductive film can be exemplified in the following six forms, but it is not limited to these.

(1) Substrate film/easy adhesion layer/transparent conductive layer

(2) Substrate film/easy adhesion layer/hard coating/transparent conductive layer

(3) Substrate film/easy adhesion layer/IM (index matching) layer/transparent conductive layer

(4) Substrate film/easy adhesion layer/hard coat layer/IM (index matching) layer/transparent conductive layer

(5) Substrate film/easy adhesion layer/hard coating (high refractive index and also used as IM)/transparent conductive layer

(6) Substrate film/easy adhesion layer/hard coat layer (high refractive index)/low refractive index layer/transparent conductive film

Since the IM layer itself has a multilayer structure of a high refractive index layer/low refractive index layer (the transparent conductive film side is a low refractive index layer), by using it, it is difficult to see the ITO pattern when viewing a liquid crystal display screen. As in (6) above, the high refractive index layer of the IM layer and the hard coat layer may be integrated, which is preferable from the viewpoint of thinning.

The structures of (3) to (6) above are particularly suitable for use in capacitive touch panels. In addition, the above-mentioned structures (2) to (6) are preferable from the viewpoint of preventing oligomers from precipitating on the surface of the base film, and it is preferable to provide a hard coat layer on the other side of the base film.

The transparent conductive layer on the substrate film is formed of conductive metal oxide. The conductive metal oxide constituting the transparent conductive layer is not particularly limited, and is selected from the group consisting of indium, tin, zinc, gallium, antimony, titanium, silicon, zirconium, magnesium, aluminum, gold, silver, copper, palladium, and tungsten. Conductive metal oxide of at least one metal in the group. The metal oxide may further contain metal atoms shown in the above group as required. The preferred transparent conductive layer is, for example, a tin-doped indium oxide (ITO) layer and an antimony-doped tin oxide (ATO) layer, and more preferably an ITO layer. In addition, it can also be Ag nanowire, Ag ink, self-organized conductive film of Ag ink, mesh electrode, CNT ink, conductive polymer.

The thickness of the transparent conductive layer is not particularly limited, and is preferably 10 nm or more, more preferably 15-40 nm, and still more preferably 20-30 nm. When the thickness of the transparent conductive layer is 15 nm or more, it is easy to obtain a good continuous film having a surface resistance of, for example, 1×103 Ω/□ or less. Moreover, when the thickness of the transparent conductive layer is 40 nm or less, it can be made into a layer with higher transparency.

The transparent conductive layer can be formed according to well-known procedures. Examples include vacuum evaporation, sputtering, and ion plating. The transparent conductive layer may be amorphous or crystalline. As a method of forming a crystalline transparent conductive layer, it is preferable to form an amorphous film on a substrate, and then heat and crystallize the amorphous film and the flexible transparent substrate.

The transparent conductive film of the present invention can be patterned by removing a part of the surface of the transparent conductive layer. The transparent conductive film in which the transparent conductive layer is patterned has: a pattern forming part where a transparent conductive layer is formed on a base film; and an opening part without a transparent conductive layer on the base film. For example, the shape of the pattern forming part may include a square shape and the like in addition to a strip shape.

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

When the alignment film is used as the anti-scattering film of the surface cover of the image display device, the alignment film can be arranged on the light source side or the visible side of the surface cover. In addition, it may also have a laminated glass structure in which glass is laminated on both sides of the alignment film. When the alignment film is located on the light source side of the surface cover, it is better to provide an anti-reflection layer on the side of the alignment film opposite to the surface cover. By setting the anti-reflection layer, a bright and clear image can be obtained.

When the alignment film is used as an anti-scattering film, it is preferable to impart an ultraviolet absorbing function to the alignment film. The ultraviolet absorption function can be provided by adding an ultraviolet absorber to the alignment film, or applying an ultraviolet absorption coating on the visible side of the alignment film, or the like. When the alignment film is located on the visible side of the surface cover, it is preferable to provide an anti-reflection layer, an anti-glare layer, an anti-static layer, an anti-fouling layer, etc., on the side of the alignment film opposite to the surface cover. At this time, an anti-reflection layer can be provided on the light source side of the surface cover of the outermost surface, or it can be bonded with other members on the visible side through adhesive materials.

The polarizer protective film, the base film, and the anti-scattering film may contain various additives within a range that does not hinder the effects of the present invention. Examples include ultraviolet absorbers, inorganic particles, heat-resistant polymer particles, alkali metal compounds, alkaline earth metal compounds, phosphorus compounds, antistatic agents, light stabilizers, flame retardants, heat stabilizers, antioxidants, gel inhibitors, Surfactant, etc. In addition, in order to exert high transparency, it is also preferable that the polyester film contains substantially no particles. "Substantially free of particles" refers to, for example, when inorganic particles are used to quantify inorganic elements by X-ray fluorescence analysis, the content by weight is 50 ppm or less, preferably 10 ppm or less, particularly preferably for detection Below the limit.

The alignment film can have various functional layers. As such a functional layer, for example, a layer selected from the group consisting of a hard coat layer, an anti-glare layer, an anti-reflection layer, a low-reflection layer, a low-reflection anti-glare layer, an anti-reflection anti-glare layer, an antistatic layer, a silicone layer, an adhesive layer, One or more of the group of antifouling layer, water repellent layer and blue light filter layer. By providing an anti-glare layer, an anti-reflective layer, a low-reflective layer, a low-reflective anti-glare layer, and/or an anti-reflective anti-glare layer, it can also be expected to have an effect of improving color spots when viewed obliquely.

When setting various functional layers, it is preferable that the surface of the alignment film has an easy-adhesion layer. At this time, from the viewpoint of suppressing interference caused by reflected light, it is preferable to adjust the refractive index of the easy-adhesive layer to near the geometric mean of the refractive index of the functional layer and the refractive index of the alignment film. The refractive index of the easy-adhesive layer can be adjusted by a well-known method, and can be easily adjusted by, for example, making the adhesive resin contain titanium, zirconium, or other metal species.

(Hard coating)

The hard coat layer only needs to be a layer with hardness and transparency. It is usually made of ionizing radiation curable resin that is typically cured by ultraviolet rays or electron beams, or thermosetting resin that is cured by heat. It is formed in the form of "hardened resin layer of various hardening resins". In order to impart appropriate flexibility and other physical properties to these curable resins, thermoplastic resins and the like may be appropriately added. Among the curable resins, ionizing radiation curable resins are preferred based on the availability of representative and excellent hard coating films.

As the ionizing radiation curable resin, a conventionally known resin may be suitably used. Furthermore, as ionizing radiation curable resins, radically polymerizable compounds with ethylenic double bonds, cationically polymerizable compounds such as epoxy compounds, etc. can be typically used. These compounds are monomers, oligomers, and prepolymers. Forms such as polymers can be used alone or in appropriate combination of two or more. Representative compounds are various (meth)acrylate-based compounds that are radically polymerizable compounds. Among (meth)acrylate-based compounds, as compounds used with relatively low molecular weights, for example, polyester (meth)acrylates, polyether (meth)acrylates, (meth)acrylates, Epoxy (meth)acrylate, urethane (meth)acrylate, etc.

As the monomer, for example, monofunctional monomers such as ethyl (meth)acrylate, ethylhexyl (meth)acrylate, styrene, methylstyrene, and N-vinylpyrrolidone; or for example, trimethylolpropane tri( Meth) acrylate, tripropylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, neopentyl erythritol tri (meth) acrylate, dineopentaerythritol hexa (meth) Multifunctional monomers such as acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, and the like can be suitably used. (Meth)acrylate means acrylate or methacrylate.

類、安息香、安息香甲醚等。若為陽離子聚合系時，作為光聚合起始劑，可單獨或混合使用芳香族重氮鹽、芳香族鋶鹽、芳香族錪鹽、茂金屬化合物、安息香磺酸酯等。 When the ionizing radiation curable resin is cured by an electron beam, a photopolymerization initiator is not required, and when it is cured by ultraviolet rays, a well-known photopolymerization initiator must be used. For example, in the case of a radical polymerization system, as a photopolymerization initiator, acetophenones, benzophenones, and 9-oxysulfur can be used alone or in combination.

Class, benzoin, benzoin methyl ether and so on. In the case of a cationic polymerization system, as a photopolymerization initiator, aromatic diazonium salts, aromatic sulfonium salts, aromatic iodonium salts, metallocene compounds, benzoin sulfonate, etc. can be used alone or in combination.

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

In the ionizing radiation curable resin, in order to adjust proper physical properties, etc., thermoplastic resin or thermosetting resin can be added appropriately. As a thermoplastic resin or a thermosetting resin, various types are mentioned, for example, an acrylic resin, a urethane resin, a polyester resin, etc. are mentioned.

In order to impart light resistance to the hard coat layer and prevent discoloration, strength deterioration, and cracking caused by ultraviolet rays contained in sunlight, etc., it is also preferable to add an ultraviolet absorber to the ionizing radiation curable resin. When an ultraviolet absorber is added, in order to prevent the ultraviolet absorber from hindering the hardening of the hard coat layer, it is preferable that the ionizing radiation curable resin is hardened by electron beam. As the ultraviolet absorber, any organic ultraviolet absorber such as benzotriazole-based compounds and benzophenone-based compounds, or inorganic ultraviolet absorbers such as particulate zinc oxide, titanium oxide, and cerium oxide with a particle size of 0.2μm or less Just wait for the publicly known things to be selected and used. The amount of ultraviolet absorber added is about 0.01 to 5 mass% in the ionizing radiation curable resin composition. In order to further improve the light resistance, it is better to use it together with an ultraviolet absorber and add a free radical scavenger such as a hindered amine-based free radical scavenger. In addition, the electron beam irradiation system uses an acceleration voltage of 70kV~1MV and a radiation dose of about 5~100kGy (0.5~10Mrad).

(Anti-glare layer)

As the anti-glare layer, what is known in the past may be suitably used, and it is generally formed as a layer in which an anti-glare agent is dispersed in a resin. As the anti-glare agent, inorganic or organic fine particles can be used. The shape of these particles is spherical, elliptical, etc. Preferably, the particles should be transparent. Such fine particles include, for example, silica beads as inorganic fine particles, and resin beads as organic fine particles. Examples of resin beads include styrene beads, melamine beads, acrylic beads, acrylic-styrene beads, polycarbonate beads, polyethylene beads, benzoguanamine-formaldehyde beads, and the like. In terms of fine particles, generally, 2 to 30 parts by mass can be added to 100 parts by mass of the resin, preferably about 10 to 25 parts by mass.

The above-mentioned resin system in which the anti-glare agent is dispersed and retained is the same as the hard coat layer, so the higher the hardness, the better. Therefore, as the above-mentioned resin, for example, curable resins such as ionizing radiation-curable resins and thermosetting resins described in the above-mentioned hard coat layer can be used.

The thickness of the anti-glare layer only needs to be made to an appropriate thickness, usually about 1-20μm. The anti-glare layer can be formed using various known coating methods as appropriate. In addition, in the coating solution for forming the anti-glare layer, in order to precipitate the anti-glare agent, it is preferable to appropriately add a well-known anti-settling agent such as silica.

(Anti-reflective layer)

As the anti-reflection layer, what is known in the past may be suitably used. Generally speaking, the anti-reflection layer includes at least a low refractive index layer, and further includes a low refractive index layer and a high refractive index layer (with a refractive index higher than the low refractive index layer) alternately adjacent to the laminated layer, and the surface side is the low refractive index layer The multi-layered layer. The thickness of the low-refractive index layer and the high-refractive index layer may be made to an appropriate thickness for the application, and it is preferable that each of the adjacent laminated layers is about 0.1 μm, and when only the low-refractive index layer is only, it is about 0.1 to 1 μm.

Examples of the low refractive index layer include: a layer in which low refractive index materials such as silicon oxide and magnesium fluoride are contained in a resin, a layer in which low refractive index resins such as fluorine-based resins are contained, and a low refractive index resin in which low refractive index materials are contained In the layer, a layer containing low refractive index substances such as silicon oxide and magnesium fluoride is formed by a thin film formation method (such as physical or chemical vapor deposition methods such as vapor deposition, sputtering, CVD, etc.), and silicon oxide is used. The sol solution is a film formed by a sol-gel method in which a silica gel film is formed, or a layer in which void-containing particles, which are low refractive index substances, are contained in a resin.

The above-mentioned void-containing particles refer to particles containing gas inside, particles containing a porous structure with gas, etc., that is, particles in which the apparent refractive index of the entire particle decreases due to the voids created by the gas relative to the original refractive index of the solid part of the particle. Examples of such void-containing particles include silica particles disclosed in JP 2001-233611 A and the like. As the void-containing particles, in addition to inorganic substances such as silica, hollow polymer particles disclosed in Japanese Patent Application Laid-Open No. 2002-805031 and the like can be cited. The particle size of the void-containing particles is, for example, about 5 to 300 nm.

Examples of the high refractive index layer include a layer in which a high refractive index substance such as titanium oxide, zirconium oxide, and zinc oxide is contained in a resin, a layer in which a high refractive index resin such as a fluorine-free resin is contained, and a layer in which a high refractive index substance is contained in a high refractive index. A layer in a high-performance resin, a layer containing high refractive index substances such as titanium oxide, zirconium oxide, zinc oxide, etc., formed by a thin film formation method (e.g., physical or chemical vapor deposition such as vapor deposition, sputtering, CVD, etc.), etc. .

(Antistatic layer)

As the antistatic layer, what is known in the past may be appropriately used, and generally, it is formed in the form of a layer containing an antistatic layer in a resin. As the antistatic layer, organic or inorganic compounds can be used. For example, as the antistatic layer of organic compounds, cationic antistatic agents, anionic antistatic agents, amphoteric antistatic agents, nonionic antistatic agents, organometallic antistatic agents, etc. can be cited, and these In addition to being used as low-molecular compounds, antistatic agents are also used as high-molecular compounds. As an antistatic agent, conductive polymers such as polythiophene and polyaniline can also be used. Furthermore, as an antistatic agent, conductive fine particles containing metal oxides, etc. can still be used. Regarding the particle size of the conductive fine particles, based on transparency, for example, the average particle size is about 0.1 nm to 0.1 μm. In addition, 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 , and ATO (antimony-doped tin oxide) , AZO (aluminum-doped zinc oxide), etc.

In the case of the above-mentioned resin containing an antistatic layer, for example, in addition to using a curable resin such as ionizing radiation curable resin and thermosetting resin as described in the above-mentioned hard coat layer, when an antistatic layer is formed as an intermediate layer When 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 only needs to be made into an appropriate thickness, usually about 0.01~5μm. The antistatic layer can be formed appropriately by various well-known coating methods.

When the alignment film is used as a polarizer protective film, it is better to laminate an antistatic layer on its surface. When the antistatic layer is laminated, it is preferable to laminate the antistatic layer and the anti-glare layer, or to add an antistatic agent to the anti-glare layer to have two layers. In addition, when assembling an image display device, a polarizer protective film is generally used as a processing member on the surface of the polarizer (different from the polarizer protective film, which is not finally assembled into the liquid crystal display device but is used in the manufacturing process of the liquid crystal display device. The component discarded in the middle), but the polarizing plate protective film is preferably provided with an antistatic layer on the side or the opposite side of the polarizing plate.

(Antifouling layer)

As the antifouling layer, what is known in the past can be appropriately used. Generally speaking, silicon compounds such as silicone oil and silicone resin; fluorine-based compounds such as fluorine-based surfactants and fluorine-based resins; and antifouling agents such as waxes can be used. The paint of the contaminant is formed by a well-known coating method. The thickness of the antifouling layer only needs to be made to an appropriate thickness, usually about 1~10μm.

[Example]

Hereinafter, examples are given to describe the present invention in more detail. However, the present invention is not limited by the following examples, and can be appropriately modified and implemented within the scope of the scope of the present invention, and they are all included in Within the technical scope of the present invention.

Evaluation of rainbow spots

In the image display device having the following structures 1 and 2, a polarizing film is arranged on the viewing side surface so as to be parallel to the viewing side surface so that a white image is displayed on the screen. While maintaining the aforementioned parallel state, rotate the angle between the polarizing axis of the polarizing film and the polarizing axis of the viewing side polarizer of the image display device by 360 degrees, while observing the white image to confirm the occurrence and degree of rainbow spots, according to the following Benchmark to be evaluated.

<Assessment criteria>

⊚: No iris spots are particularly observed from the front view or from the oblique direction, and the visibility is good.

○: When viewed from the front, no iris spots are particularly observed, but faint iris spots are observed when viewed from an oblique direction, but practically no problem visibility can be obtained.

×: Rainbow spots are observed both from the front and from the oblique direction.

<Structure of image display device 1>

(1) Image display unit: organic EL unit

(2) Visibility side polarizing plate: The image display unit side of the polarizing plate is laminated with TAC film (manufactured by FUJIFILM Co., Ltd., thickness 80μm) as the protective film on both sides of the polarizer containing PVA and iodine Polarizing plate made of 1/4 wavelength plate.

(3) Visual recognition side anti-scattering film: the following alignment films 1~5

In addition, the anti-scattering film is attached to the glass plate via OCA (Optical Clear Adhesive), and the image display device is assembled so that the anti-scattering film is on the side of the image display unit.

<Structure of Image Display Device 2>

(1) Backlight source: white LED or cold cathode tube

(2) Light source side polarizing plate: TAC film is used as the protective film on both sides of the polarizer containing PVA and iodine.

(3) Image display unit: liquid crystal unit

(4) Visibility side polarizing plate: A polarizing plate laminated with TAC film (manufactured by FUJIFILM Co., Ltd., thickness 80μm) as the protective film on both sides of the polarizer containing PVA and iodine

(5) Anti-scattering film on the light source side: the following alignment films 1~5

(6) Touch panel: A resistive film type touch panel, which has a structure in which a transparent conductive film made of a transparent conductive layer containing ITO is provided on a glass substrate, and a spacer is arranged therebetween.

Manufacturing example-PET (A)

At the time when the temperature of the esterification reaction tank reached 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 and 0.064 parts as a catalyst were charged while stirring. Parts by mass of magnesium acetate tetrahydrate and 0.16 parts by mass of triethylamine. Next, the pressure was increased and the pressure was subjected to the esterification reaction under the conditions of a gauge pressure of 0.34 MPa and 240° C., the esterification reaction tank was returned to normal pressure, and 0.014 parts by mass of phosphoric acid was added. Then, it heated up to 260 degreeC over 15 minutes, and 0.012 mass parts of trimethyl phosphates were added. Then, 15 minutes later, the dispersion treatment was performed with a high-pressure disperser, and 15 minutes later, the obtained esterification reaction product was transferred to the polycondensation reaction tank, and the polycondensation reaction was performed at 280°C under reduced pressure.

After the polycondensation reaction is completed, filter paper made of Naslon (registered trademark) with a diameter of 5μm is filtered by 95%, extruded from the nozzle into a strand shape, and filtered beforehand (pore size of 1μm or less) ) Cooling water to cool and solidify, and then cut into pellets. The intrinsic viscosity of the obtained polyethylene terephthalate resin (A) was 0.62 dl/g, and it contained substantially no inactive particles and internally precipitated particles. (Hereinafter referred to as PET(A).)

Alignment 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. The polymer is filtered with a stainless steel sintered filter material (with a nominal filtration accuracy of 10μm and 95% of particles are filtered out), extruded from a nozzle into a sheet, and then wound on a casting drum with a surface temperature of 30°C by using an electrostatic casting method ( Casting drum) and solidified by cooling to make an unstretched film.

Guide the unstretched film to the tenter stretcher, clamp the end of the film with a clip on one side, and guide it to a hot air zone with a temperature of 125°C, and extend it 4.0 times in the width direction. Next, while maintaining the width extending in the width direction, the treatment was performed at a temperature of 225°C for 30 seconds, and then a 3% relaxation treatment in the width direction was performed to obtain a uniaxially aligned alignment film 1 with a film thickness of about 50μm. . The Re of the alignment film 1 is 5177 nm, the Rth is 6602 nm, and the Re/Rth is 0.784.

Alignment film 2

A uniaxially aligned alignment film 2 was produced in the same manner as the alignment film 1 except that the thickness of the unstretched film was changed to about 100 μm. The Re of the alignment film 2 is 10200 nm, the Rth is 13233 nm, and the Re/Rth is 0.771.

Alignment film 3

Except that the unstretched film is heated to 105°C by the heated roller group and infrared heater, and then the roller group with the peripheral speed difference is stretched in the traveling direction by 1.5 times, and then stretched in the width direction by the same method as the alignment film 1 Except for 4.0 times, a biaxially aligned alignment film 3 with a film thickness of about 50 μm was prepared in the same manner as the alignment film 1. The Re of the alignment film 3 is 3915 nm, the Rth is 6965 nm, and the Re/Rth is 0.562.

Alignment film 4

Except for extending 3.6 times in the direction of travel and 4.0 times in the width direction, a biaxially aligned alignment film 4 with a film thickness of about 38 μm was prepared in the same manner as the alignment film 3. The Re of the alignment film 4 is 1178 nm, the Rth is 6365 nm, and the Re/Rth is 0.185.

Alignment film 5

A uniaxially aligned alignment film 5 was produced in the same manner as the alignment film 1 except that the thickness of the unstretched film was changed to about 200 μm. The Re of the alignment film 5 is 20500 nm.

The hysteresis (Re) and thickness direction hysteresis (Rth) are measured as follows. That is, using two polarizing plates, the orientation of the main axis of the film is determined, and a 4cm×2cm rectangle is cut out so that the orientation of the main axis is orthogonal to form a measurement sample. For this sample, the refractive index (Nx, Ny) of the two orthogonal axes and the refractive index (Nz) in the thickness direction were obtained by using an Abbe refractometer (NAR-4T manufactured by ATAGO), and the aforementioned two The absolute value of the refractive index difference between the axes (|Nx-Ny|) is regarded as the inequality of the refractive index (△Nxy). The thickness d (nm) of the film was measured with an electronic micrometer (Millitron 1245D manufactured by FEINPRUF), and the unit was converted into nm. Obtain the hysteresis (Re) from the product (△Nxy×d) of the refractive index inequality (△Nxy) and the film thickness d (nm). In addition, Nx, Ny, Nz and the film thickness d (nm) are calculated in the same way as the measurement of the hysteresis, and the average value of (△Nxz×d) and (△Nyz×d) is calculated to obtain the thickness direction hysteresis (Rth ).

The evaluation results are shown in Table 1 below.

As shown in Table 1 above, it can be confirmed that by arranging the alignment film with a hysteresis of 3000nm or more on the viewing side of the viewing side polarizer, even when organic EL cells and liquid crystal cells are used (except for cold cathode tubes where the light source is If any one of them is used as an image display unit, the occurrence of rainbow spots can also be suppressed.

E1‧‧‧Organic EL display device

E4‧‧‧Organic EL Unit

E5‧‧‧Visibility side polarizer

E6‧‧‧Touch Panel

E8‧‧‧Visibility side polarizer

E10a‧‧‧Polarizer protective film

E10b‧‧‧Visibility side polarizer protective film

E11‧‧‧Transparent conductive film on the light source side

E11a‧‧‧Light source side substrate film

E11b‧‧‧Transparent conductive layer

E12‧‧‧Visible side transparent conductive film

E12a‧‧‧Visibility side substrate film

E12b‧‧‧Transparent conductive layer

E13‧‧‧Spacer

E14‧‧‧Anti-scattering film on the light source side

E15‧‧‧Visibility side anti-scattering film

E16‧‧‧1/4 wavelength plate

Claims (4)

An organic EL display device having: (1) an organic EL unit; and (2) a circular polarizing plate disposed on the viewing side of the organic EL unit, the circular polarizing plate having a sheet laminated on the viewing side of the polarizer A polarizer protective film that satisfies the hysteresis of 6000nm or more and 10200nm or less and the ratio of the hysteresis (Re) to the thickness direction hysteresis (Rth) (Re/Rth) of 0.2 or more and 1.2 or less. Such as the organic EL display device of claim 1, wherein the thickness of the polarizer protective film is 15-300 μm. The organic EL display device of claim 1 or 2, wherein the ratio (Re/Rth) of the hysteresis (Re) to the thickness direction hysteresis (Rth) is 0.5 or more and 1.2 or less. The organic EL display device of claim 1 or 2, wherein the polarizer protective film is a polyester film.

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