TWI653473B - Image display device - Google Patents

Abstract

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

An image display device comprising: (1) an organic EL unit; (2) a polarizer disposed closer to the visual recognition side than the aforementioned organic EL unit; and (3) having a wavelength of 3000 nm or more and 150,000 nm closer to the visual recognition side than the polarizer. The following hysteresis alignment film.

Description

Image display device

The present invention relates to an image display device.

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

In this way, the opportunity to view the image display device through a polarizing filter such as sunglasses increases. On the other hand, for image display devices, alignment films have 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 the image with a polarizing filter, the hue due to rainbow spots and the like Disturbance causes a problem that visibility deteriorates (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.

As a result of repeated studies day and night in order to solve the above problems, the present inventors have found that the above problems can be solved by controlling the retardation of the alignment film. Based on the findings, the inventors have repeated the research and improvement several times, and finally completed the present invention.

The representative invention is as follows:

Item 1.

An image display device comprising: (1) an image display unit; (2) a polarizer disposed closer to the visual recognition side than the aforementioned image display unit; and (3) having a wavelength of 3000 nm or more and 150,000 nm closer to the visual recognition side than the polarizer The following hysteresis alignment film.

Item 2.

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

Item 3.

The image display device according to item 1 or 2, wherein the aforementioned 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 in image quality caused by the tonal confusion represented by the rainbow spots that occur when viewed through a polarizing filter is reduced. In addition, in this specification, "iris" is a concept including "color unevenness", "color shift", and "interference color".

E1‧‧‧Organic EL display device

E4‧‧‧Organic EL Unit

E5‧‧‧Side-view side polarizer

E6‧‧‧Touch Panel

E7‧‧‧Light source side polarizer

E8‧‧‧Side-view side polarizer

E9a‧‧‧Polarizer Protection Film

E9b‧‧‧Polarizer Protection Film

E10a‧‧‧Polarizer Protection Film

E10b‧‧‧Side Polarizer Protection Film

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

E11a‧‧‧Light source side substrate film

E11b‧‧‧Transparent conductive layer

E12‧‧‧Transparent conductive film

E12a‧‧‧Viewable side substrate film

E12b‧‧‧Transparent conductive layer

E13‧‧‧spacer

E14‧‧‧anti-scatter film on light source side

E15‧‧‧Recognized side anti-scatter film

E16‧‧‧1 / 4 wave plate

L1‧‧‧LCD display device

L2‧‧‧light source

L3‧‧‧ Light source side polarizer

L4‧‧‧LCD unit

L5‧‧‧ side polarizer

L6‧‧‧Touch Panel

L7‧‧‧light source side polarizer

L8‧‧‧ side-view polarizer

L9a‧‧‧Polarizer Protective Film

L9b‧‧‧Polarizer Protection Film

L10a‧‧‧Polarizer Protection Film

L10b‧‧‧ side view polarizer protective film

L11‧‧‧Transparent conductive film on light source side

L11a‧‧‧Light source side substrate film

L11b‧‧‧Transparent conductive layer

L12‧‧‧Recognized side transparent conductive film

L12a‧‧‧Viewable side substrate film

L12b‧‧‧Transparent conductive layer

L13‧‧‧ spacer

L14‧‧‧ Anti-scatter film on the light source side

L15‧‧‧ side anti-scatter film

E17‧‧‧Substrate

E18‧‧‧Anode

E19‧‧‧Organic emitting layer

E20‧‧‧Cathode

FIG. 1 is a schematic cross-sectional view showing a typical 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.

[Form of Implementing Invention]

The image display device typically includes 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 diagram of an image display device (organic EL display device) using an organic EL unit as an image display unit is shown in Fig. 1. A representative diagram of an image display device (liquid crystal display device) using a liquid crystal unit as an image display unit is shown in Fig. 1. The figure is shown in Figure 2. Hereinafter, the representative structure of the image display device will be 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 specification, the side on which the image display device displays the image (the side where we view the image) is referred to as the "viewable side", and the side opposite to the viewable side (that is, in the organic EL display device, is provided with The side of the organic EL unit that also functions as a light source; in a liquid crystal display device, the side on which the light source is arranged) is called the "light source side". In FIGS. 1 and 2, the right side is the visual recognition side, and the left side is the light source side.

As shown in FIG. 1, the organic EL display device (E1) may include an organic EL unit (E4), a polarizing plate (E5), and a touch panel (E6). A quarter-wave plate (E16) may be provided between the organic EL unit (E4) and the polarizing plate (E5). The polarizing plate (E5) is typically provided on the visible side of the organic EL unit (E4), and has a structure in which a polarizer protective film (E10a, E10b) is laminated on both sides of a film called a "polarizer (E8)". The touch panel (E6) is typically located closer to the viewing side than 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 substrate film (E11a, E12a) and a transparent conductive layer (E11b, E12b) are laminated. On the light source side and the viewing side of the touch panel (E6), a transparent substrate anti-scattering film (E14, E15) can be provided through any adhesive layer.

As shown in FIG. 2, the liquid crystal display device (L1) may include a light source (L2), a liquid crystal cell (L4), and a touch panel (L6). On both the light source side and the viewing side of the liquid crystal cell (L4), a polarizing plate (the light source side polarizing plate (L3) and the viewing side polarizing plate (L5)) is typically provided. Each polarizer (L3, L5) typically has a structure in which a polarizer protective film (L9a, L9b, L10a, L10b) is laminated on both sides of a film called a "polarizer (L7, L8)". In this specification, the polarizing plate (L5) located closer to the viewing side than the image display unit is also referred to as a "viewing side polarizing plate", and the polarizer (L8) constituting it is referred to as a "viewing side polarizer". The touch panel (L6) is typically located closer to the viewing side than the viewing-side polarizer (L5). Touch panel (L6) typical on It 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 substrate film (L11a, L12a) and a transparent conductive layer (L11b, L12b) are laminated. In addition, on the light source side and the visual side of the touch panel (L6), an anti-scattering film (L14, L15) as a transparent substrate can be provided through any adhesive layer.

In addition, in FIG. 1 and FIG. 2, a touch panel (E6, L6) is shown on the viewing side of the viewing-side polarizing plate (E5, L5), but it is not necessary to have a touch panel, and it can have any film . For example, there may be one anti-scattering film on the viewing side of the viewing-side polarizer. The touch panel is not limited to the above-mentioned resistive film type touch panel, and other types of touch panels such as a projection type power type can be used. For example, one transparent conductive film may be used. The anti-scattering film does not necessarily need to be disposed on both sides of the touch panel, and may be configured to be disposed on either side or not to be disposed on both sides.

<Position of alignment film>

In the image display device, an alignment film can be used for various purposes. In this specification, an alignment film refers to a polymer film having birefringence. In terms of an image display device, from the viewpoint of improving visibility, it is preferable to have an alignment film having a retardation of 3,000 nm to 150,000 nm closer to the viewing side than the viewing side polarizer. In this specification, an alignment film having a hysteresis of 3000 nm to 150,000 nm is also referred to as a "high hysteresis alignment film". Therefore, in the liquid crystal display device shown in FIGS. 1 and 2, the alignment film is typically used for a polarizer protective film (E10b, L10b) located closer to the viewing side of the polarizer (E8, L8). (Hereinafter referred to as the "view-side polarizer protective film"), a transparent conductive film (E11, L11) substrate film (E11a, L11a) (hereinafter referred to as "light source side substrate film"), a substrate film of a transparent conductive film (E12, L12) located closer to the viewing side than the spacer (E13, L13) (E12a, L12a) (hereinafter referred to as the "view-side substrate film"), a scattering prevention film (E14, L14) (hereinafter referred to as "light source side anti-scattering film") and / or anti-scattering film (E15, L15) located closer to the visual recognition side of the substrate film (E12a, L12a) on the visual side (hereinafter referred to as "visual anti-scattering film" film").

The number of high hysteresis alignment films used in the image display device is arbitrary and is not particularly limited, and it is preferable to use at least one high hysteresis alignment film at the position as described above. As a representative example of such an image display device, the organic EL display device or the liquid crystal display device shown in FIG. 1 or FIG. 2 is provided at a position corresponding to the anti-scattering film (E15, L15) on the visual 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 thereof.

As another representative example of an image display device, a "surface cover integrated touch panel" having a capacitive touch panel provided on a surface cover of glass or the like can be cited. A panel with a high hysteresis alignment film. As a specific configuration 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-latency alignment film is bonded 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-type integrated touch panel. The transparent conductive layer may be provided on either the light source side or the visible side of the surface cover, but it is preferably provided on the light source side.

(B) A glass plate is laminated on both sides of the high-latency alignment film to form a laminated glass, and a transparent conductive layer surface cover-integrated touch panel is provided on the light source side of the laminated glass.

(C) A transparent conductive layer is provided on one side of the high hysteresis film, and it is adhered to the surface cover integrated touch panel on the light source side or the visible side of the surface cover. If it is adhered to the light source side, it can be adhered to the surface of one side of the high-latency alignment film that is not provided with a transparent conductive layer or either side of 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 of 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. In addition, if the innermost surface is a transparent conductive layer, an electrode protective coating may be provided, and an anti-reflection layer may be provided thereon. Furthermore, an anti-reflection layer, an anti-glare layer, an anti-static layer, an anti-fouling layer, and the like can be provided on the outermost surface (the surface on the most visible side) of the surface cover integrated touch panel. In addition, the bonding of various parts is more suitable for using a baseless optical adhesive.

(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 the surface cover and the high-latency 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-latency alignment film, the bonding order is arbitrary.

(F) A surface cover-integrated touch panel in which a transparent conductive layer is provided on one or both sides of a sheet, such as glass, and is bonded to a surface cover and a high-latency 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-latency alignment film, the other order of lamination is arbitrary.

The lower limit of the retardation of the high retardation alignment film is preferably 4500 nm or more, preferably 6000 nm or more, preferably 8000 nm or more, and more preferably 10,000 nm or more, from the viewpoint of reducing iridescence. On the other hand, as far as the upper limit of the hysteresis of the alignment film is concerned, the use of a polyester film with a higher hysteresis cannot substantially achieve further improvement in visibility, and as the retardation increases, the thickness of the alignment film also increases. The upward tendency may be contrary to the requirement for thinning. From 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 retardation may be the same or different.

From the viewpoint of more effective suppression of rainbow spots, the ratio of the retardation (Re) to the thickness direction retardation (Rth) (Re / Rth) of the highly retarded alignment film is preferably 0.2 or more, preferably 0.5 or more, and more preferably 0.6 or more. The hysteresis in the thickness direction refers to the average value of the hysteresis obtained by multiplying the two birefringences ΔNxz and ΔNyz by the thickness d of the film when viewed from the cross section of the film thickness direction. The larger the Re / Rth, the more the birefringence effect increases its isotropy, which can more effectively suppress those who produce rainbow spots on the screen. In addition, in this specification, when only described as "hysteresis", it means the in-plane retardation.

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 more positive it is with the alignment direction The mechanical strength in the direction of intersection 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, the viewing angle characteristics (180 degrees left and right, and 120 degrees up and down) required by the image display device can still be satisfied.

The hysteresis of an alignment film can be measured by a well-known method. Specifically, it can be obtained by measuring the refractive index and 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 Measurement Co., Ltd.).

The angle between the alignment axis of the high retardation alignment film and the polarizing axis of the viewing side polarizer (assuming that the high retardation alignment film and the polarizer are in the same plane state) 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 Degree ± 2 degrees, 45 degrees ± 1 degree, 45 degrees. In this specification, the term "below" means the meaning of adding a value after "±". Therefore, for example, the aforementioned "45 degrees ± 20 degrees or less" means that a range of up and down 20 degrees is allowed around 45 degrees as the center.

Those who arrange a polarizer and a high-hysteresis alignment film in such a way that the polarizing axis and the alignment main axis satisfy a certain angle as described above can arrange the cut high-hysteresis alignment film to a specific angle between the polarizing axis of the alignment main axis and the polarizer, for example. Method, or a method of obliquely extending the high retardation alignment film.

The alignment axis of the high-latency alignment film is preferably arranged in the image display device so as to be parallel to the vertical or horizontal axis of the rectangular display screen. The reason for this is that when the alignment main axis of the high-latency alignment film is approximately parallel to the vertical axis of the display, when the screen is viewed from an oblique direction (from a horizontal direction) rather than from the front, the rainbow spots are suppressed and the visibility is excellent. On the other hand, the reason is that when the alignment axis of the high-latency alignment film is slightly consistent with the horizontal direction of the display screen, the rainbow spot is suppressed and the visibility is excellent when the screen is viewed from an oblique direction (from the horizontal direction) instead of from the front. .

The image display device only needs to have at least one high-hysteresis alignment film on the side closer to the viewing side than the viewing-side polarizer, and may have an alignment film with a retardation of less than 3000 nm at any position. Such alignment films are well known and can be obtained commercially.

The highly retarded alignment film can be produced by appropriately selecting a known method. For example, the high retardation alignment film can be selected from the group consisting of para-polyester resin, polycarbonate resin, polystyrene resin, para-polystyrene resin, polyetheretherketone resin, polyphenylene sulfide resin, cycloolefin resin, The liquid crystalline polymer resin and the cellulose-based resin are produced by adding one or more of a group of resins of a liquid crystal compound. Therefore, the highly retarded alignment film can be a liquid crystal compound added to a polyester film, a polycarbonate film, a polystyrene film, a para-position polystyrene film, a polyetheretherketone film, a polyphenylene sulfide film, a cycloolefin film, Liquid crystal film and film made of cellulose resin.

Polycarbonate and / or polyester, and para-polystyrene are preferred raw materials for high-hysteresis alignment films. These resins are excellent in transparency, and also excellent in thermal and mechanical properties, and can easily control hysteresis by stretching. Polyesters represented by polyethylene terephthalate and polyethylene naphthalate have large inherent birefringence, and even with thin films, it is easier to obtain large hysteresis and is better. Especially polyethylene naphthalate in polyester when Since the middle complex refractive index is large, it is particularly suitable when it is desired to increase the hysteresis or to reduce the film thickness while maintaining high hysteresis. Taking polyester resin as a representative example, a more specific method for producing a high-hysteresis alignment film will be described later.

An alignment film having a hysteresis of less than 3000 nm can be appropriately selected to be manufactured by a known method. For example, it can be selected from the group consisting of polyester resin, acetate resin, polyether resin, polycarbonate resin, polyamide resin, polyimide resin, polyolefin resin (polyethylene resin, polypropylene resin, (Cyclic polyolefins, etc.), (meth) acrylic resins, polyvinyl chloride resins, polyvinylidene chloride resins, polystyrene resins, polyvinyl alcohol resins, polyarylate resins, and polyphenylene sulfide resins, cellulose acetate Resin (cellulose triacetate, etc.) is used as a raw material. Among these, polyester resins and polyolefin resins are preferred, polyester resins are more preferred, and polyethylene terephthalate and / or polypropylene resins are more preferred.

<Manufacturing method of alignment film>

Hereinafter, a method for manufacturing an alignment film including a high-lag retardation film will be described using a polyester film as an example. The polyester film is obtained by condensing an arbitrary dicarboxylic acid and a diol. Examples of the dicarboxylic acid include terephthalic acid, isophthalic acid, phthalic acid, 2,5-naphthalenedioic acid, 2,6-naphthalenedioic acid, 1,4-naphthalenedioic acid, 1,5 -Naphthalenedicarboxylic acid, diphenylcarboxylic acid, diphenoxysuccinic acid, diphenylarsinocarboxylic acid, anthracenedioic acid, 1,3-cycloglutaric acid, 1,3-cycloadipic acid, 1,4 -Cyclohexanedipic 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.

Examples of the diol include 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) Wait

The dicarboxylic acid component and the diol component constituting the polyester film may be used singly or in combination of two or more kinds. Specific examples of the polyester resin constituting the polyester film include polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, and the like. , Preferably polyethylene terephthalate and polyethylene naphthalate, and more preferably polyethylene terephthalate. The polyester resin may also contain other copolymerization components. From the viewpoint of mechanical strength, the proportion of the copolymerization components is preferably 3 mol% or less, more preferably 2 mol% or less, and even 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 hysteresis by drawing.

The polyester film can be obtained in accordance with a general manufacturing method. Specifically, the non-oriented polyester is formed by melting a polyester resin and extruding it into a sheet shape. After the polyester resin is stretched in a longitudinal direction at a temperature higher than the glass transition temperature by a roller speed difference, the film is stretched. The web stretches in the transverse direction and is heat-treated with an oriented 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 at an angle of 45 degrees.

The manufacturing conditions for producing a polyester film can be appropriately set according to a well-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 magnification is usually 1.0 to 3.5 times, preferably 1.0 to 3.0 times. The horizontal extension ratio is usually 2.5 to 6.0 times, preferably 3.0 to 5.5 times.

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

In order to suppress the hysteresis of the polyester film, the smaller the thickness unevenness of the film, the better. When the longitudinal stretching magnification is reduced to give a hysteresis difference, the value of the vertical thickness unevenness may become high. The value of the vertical thickness unevenness rises in a specific range of the stretch magnification. Therefore, it is desirable to set the film forming conditions so as to avoid such a range.

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

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

<Image display unit and light source>

In the image display device, it is preferable that the light emitted from the image display unit has a continuous and wide light emission spectrum from the viewpoint of suppressing iridescence. Here, the "continuous and wide-ranging luminescence spectrum" refers to a luminescence spectrum in a wavelength region of at least 450 to 650 nm, preferably in a visible light region having no wavelength region with a light intensity of zero. 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 unit as the image display unit, the organic EL unit itself has a function as a light source having a continuous and wide light emission spectrum. On the other hand, when the image display device is provided with a liquid crystal unit as the image display unit, it is preferable to have a light source having a continuous and wide light emission spectrum.

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

As the organic EL unit, an organic EL unit well known in the technical field can be appropriately selected and used. Using organic EL units, in a wide viewing angle, high alignment Better than the 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 transparent electrodes, which are sequentially laminated on a transparent substrate (E17) from the recognized side. Structured light emitter (organic electroluminescent light emitter). In the organic EL unit, when a voltage is applied between the anode and the cathode, a hole (hole) injected from the anode and electrons injected from the cathode are recombined in the organic light emitting layer to emit light.

As the transparent substrate, any transparent substrate can be used. For example, the transparent substrate may be selected from the group consisting of a glass substrate, a ceramic substrate, a semiconductor substrate, a metal substrate, and a plastic substrate. As a specific plastic substrate, the transparent resin film conventionally used as the base material film for a touch panel mentioned later is mentioned. The transparent substrate can also be provided with a surface treatment layer as required. Examples of the surface treatment layer include a moisture barrier layer, a gas barrier layer, a hard coat layer, and an undercoat layer.

Examples of the materials constituting the anode and the cathode include metals, metal oxides, alloys, 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, 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 a 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 a range of, for example, 10 nm to 1000 nm, preferably 10 nm to 200 nm.

The organic light-emitting layer is a layer having a function of providing a field of recombination of holes and electrons when a voltage is applied to emit light. The organic light-emitting layer contains an organic light-emitting material, and may have a single-layer structure or a multilayer structure of two or more layers. In the case of a laminated structure, each layer can emit light of different emission colors. The thickness of the organic light-emitting layer is arbitrary, and can be appropriately set within a 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 material. Specifically, olefin-based light-emitting materials including 4,4 '-(2,2-diphenylvinyl) biphenyl; 9,10-bis (2-naphthyl) anthracene; and 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-biphenyl) -9,9'-bianthracene, 9,10,9 ', 10'-tetraphenyl-2,2'-bianthracene, 1,4- Anthracene-based light-emitting materials such as bis (9-phenyl-10-anthracene) benzene; Spiro-based light-emitting materials such as 2,7,2 ', 7'-di (2,2-diphenylvinyl) spirofluorene; 4 Carbazole-based light-emitting materials such as 4,4-dicarbazole biphenyl and 1,3-dicarbazolylbenzene; fluorene-based light-emitting materials such as 1,3,5-trinuclearin benzene and the like 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 substrate from the influence of the atmosphere. By providing the sealing member, it is possible to prevent the light emitting characteristics of the organic light emitting layer from being deteriorated due to atmospheric moisture and oxygen.

The organic EL element may further include an arbitrary 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.

When an organic EL unit is used as the image display unit, in general, a polarizing plate in the image display device is not necessary. However, since the thickness of the organic light-emitting layer is about 10 nm, it is extremely thin. When external light is reflected by the metal electrode and emitted to the viewing side again, when viewed from the outside, the display surface of the organic EL display device sometimes looks like a mirror surface. In order to shield such specular reflection of external light, it is better to provide a polarizing plate on the visible side of the organic EL unit, and further to provide a 1/4 wavelength plate between the organic EL unit and the aforementioned polarizing plate. The combination of these viewing-side polarizing plates and a quarter-wave plate is used to form a circularly polarizing plate, and the external light reflected by the metal electrode in the organic EL unit is shielded by the circularly 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 for the liquid crystal cell, and the method or structure is not particularly limited. For example, a liquid crystal cell using a VA mode, an IPS mode, a TN mode, an STN mode, or a bend alignment (π-type) can be appropriately selected. 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 sides of a film-shaped polarizer are sandwiched by two protective films (the so-called "polarizer protective film"). As the polarizer, any polarizer (or polarizing film) used in this technical field can be appropriately selected and used. As a representative polarizer, a dichroic material such as iodine is dyed and attached to a polyvinyl alcohol (PVA) film, but it is not limited to this, and a well-known and future-developed polarizer can be appropriately selected and used.

Commercially available products can be used for the PVA film, such as "Kuraray Vinylon (manufactured by Kuraray Co., Ltd.)", "Tohcello Vinylon (manufactured by Tohcello Co., Ltd.)", "Nichigo Vinylon (manufactured by Japan Synthetic Chemical Co., Ltd.)", and the like. Examples of the dichroic material include iodine, a diazonium compound, and a polymethine dye.

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

The protective film of the visible side polarizer (viewable side polarizer protective film) may be a high-hysteresis alignment film, or any film conventionally used as a polarizer protective film, and is not limited thereto.

The type of the protective film on the light source side of the visible side polarizer and the protective film on the light source side polarizer is arbitrary, and a film conventionally 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 material selected from the group consisting of a cellulose triacetate (TAC) film, an acrylic film, and a cyclic olefin-based film (for example, norbornene-based film), a polypropylene film, and a polymer. One or more non-birefringent films in the group of olefin-based films (for example, TPX).

In one embodiment, the light source side protective film of the viewing side polarizer and the light source side protective film of the light source side polarizer are preferably an optical compensation film having an optical compensation function. Such an optical compensation film can be appropriately selected in accordance with each mode of the image display unit, and examples thereof include a liquid crystal compound (such as a disc-shaped liquid crystal) selected from cellulose triacetate dispersed Resin, cyclic olefin resin (such as norbornene resin), propionyl acetate resin, polycarbonate film resin, acrylic resin, styrene acrylonitrile copolymer Resin, lactone ring-containing resin, fluorene-imide-containing polyolefin resin, etc.

The optical compensation film is commercially available, so it can be appropriately selected for use. 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 Japan), "ARTON" (manufactured by JSR Corporation), "X-plate" (manufactured by Nitto Denko Corporation), and "Z-TAC" (manufactured by FUJIFILM company) for IPS methods, "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 via an adhesive. From the viewpoint of improving adhesion, it is preferable to laminate through an adhesive. The adhesive is not particularly limited, and any one can be used. From the viewpoint of thinning the adhesive layer, an aqueous system (that is, one in which the adhesive component is dissolved or dispersed in water) is preferred. For example, when a polyester film is used as a polarizer protective film, a polyvinyl alcohol resin or a urethane resin is used as a main component, and in order to improve adhesion, an isocyanate compound or an epoxy compound may be used as required. And other compositions as adhesives. 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.

If a TAC film is used as a protective film for polarizers, a polyvinyl alcohol-based adhesive can be used for adhesion. As the polarizer protective film, when an acrylic film, a cyclic olefin-based film, a polypropylene film, or a film having low moisture permeability such as TPX is used, a photocurable adhesive is preferably used 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 is appropriately set in a range of 15 to 300 μm, preferably in a range of 30 to 200 μm.

<Touch panel, transparent conductive film, base film, anti-scattering 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 film type touch panel and a capacitive type touch panel. 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 substrate film, a high-hysteresis alignment film or another film conventionally used as a substrate film or a rigid plate such as a glass plate can be used.

Examples of other films conventionally used as a base film include various resin films having transparency. For example, a resin selected from the group consisting of polyester resin, acetate resin, polyether resin, polycarbonate resin, polyamide resin, polyimide resin, polyolefin resin, (meth) acrylic resin, and polychloride can be used. Films obtained from one or more resins in 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 base film is arbitrary, and it is preferably in the range of 15 to 500 μm.

The surface of the base film may be subjected to an etching treatment or a primer treatment such as sputtering, corona discharge, flame, ultraviolet irradiation, electron beam irradiation, formation, oxidation, and the like in advance. Thereby, the adhesiveness with the transparent conductive layer etc. which were provided in the base film can be improved. In addition, before the transparent conductive layer is provided, the surface of the base film can be dust-removed and cleaned by solvent cleaning or ultrasonic cleaning.

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

(1) Substrate film / adhesive layer / transparent conductive layer

(2) Substrate film / adhesive layer / hard coating / transparent conductive layer

(3) Substrate film / adhesive layer / IM (refractive index matching) layer / transparent conductive layer

(4) Substrate film / adhesive layer / hard coating / IM (refractive index matching) layer / transparent conductive layer

(5) Substrate film / Easy-adhesive layer / Hard coating (high refractive index doubles as IM) / Transparent conductive layer

(6) Substrate film / Easy adhesion layer / Hard coat layer (high refractive index) / Low refractive index layer / Transparent conductive film

The IM layer has a laminated structure of a high refractive index layer and a low refractive index layer (a low refractive index layer on the side of the transparent conductive film). It is difficult to see the ITO pattern when viewing the LCD screen. It is also possible to integrate the high refractive index layer of the IM layer and the hard coat layer as described in (6) above, from the viewpoint of thinning.

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

The transparent conductive layer on the substrate film is formed of a 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. A 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. 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. In addition, Ag nanowires, Ag inks, self-organized conductive films of Ag inks, mesh electrodes, CNT inks, and conductive polymers can also be used.

The thickness of the transparent conductive layer is not particularly limited, but it is preferably 10 nm or more, more preferably 15 to 40 nm, and still more 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 film having a surface resistance of, for example, 1 × 103 Ω / □ or less. When the thickness of the transparent conductive layer is 40 nm or less, a more transparent layer can be formed.

The transparent conductive layer can be formed according to a known procedure. Examples include a vacuum evaporation method, a sputtering method, and an ion plating method. The transparent conductive layer may be amorphous or crystalline. As a method for forming a crystalline transparent conductive layer, it is preferable to form the amorphous film and a flexible transparent substrate by heating and crystallization after forming the amorphous film on the 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 patterned transparent conductive film of the transparent conductive layer includes: a pattern forming portion for forming a transparent conductive layer on a base film; and an opening portion having no transparent conductive layer on the base film. Examples of the shape of the pattern forming portion include a square shape in addition to the strip shape.

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

When the alignment film is used as an anti-scattering film on a surface cover of an image display device, the alignment film can be arranged on the light source side or the visual side of the surface cover. Moreover, it may be 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 opposite side of the alignment film from the surface cover. By providing an anti-reflection layer, a bright and clear image can be obtained.

When using an alignment film as an anti-scattering film, it is preferable to provide an ultraviolet absorption function to an alignment film. The ultraviolet absorbing function can be imparted by adding an ultraviolet absorbing agent to the alignment film, or by performing ultraviolet absorbing coating on the visible side of the alignment film. When the alignment film is located on the visible side of the surface cover, an anti-reflection layer, an anti-glare layer, an antistatic layer, an anti-fouling layer, etc. are preferably provided on the opposite side of the alignment film from the surface cover. At this time, an anti-reflection layer may be provided on the light source side of the outermost surface cover plate, or may be bonded to other members on the visible side through an adhesive material.

The polarizer protective film, the base film, and the anti-scattering film may contain various additives as long as the effects of the present invention are not hindered. Examples thereof include ultraviolet absorbers, inorganic particles, heat-resistant polymer particles, alkali metal compounds, alkaline earth metal compounds, phosphorus compounds, antistatic agents, light resistance agents, flame retardants, heat stabilizers, antioxidants, gel inhibitors, Surfactants and so on. In order to exhibit high transparency, it is also preferable that the polyester film does not substantially contain particles. "Substantially free of particles" means that, for example, when inorganic particles are quantified by X-ray fluorescence analysis when the inorganic particles are quantified, the content is 50 ppm or less by weight, preferably 10 ppm or less, particularly preferably for detection. Below the limit.

The alignment film may have various functional layers. As such a functional layer, for example, a material 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, Anti-fouling layer, water-repellent layer, blue light filter layer and more. By providing an anti-glare layer, an anti-reflection layer, a low-reflection layer, a low-reflection anti-glare layer, and / or an anti-reflection anti-glare layer, the effect of improving the color spot when viewed obliquely can also be expected.

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

(Hard coating)

The hard coat layer may be a layer having hardness and transparency, and generally uses a "radiation-hardenable resin which is typically hardened by ultraviolet rays or electron beams, a thermosetting resin which is hardened by heat, etc. Various hardenable resins are formed in the form of "hardened resin layers". In order to impart appropriate flexibility and other physical properties to these curable resins, a thermoplastic resin or the like may be appropriately added. Among the curable resins, a free radiation-curable resin is preferred based on a representative and excellent hard coating film available.

As the above-mentioned free radiation-curable resin, a conventionally known resin may be appropriately used. In addition, as the radiation-hardenable resin, a radically polymerizable compound having an ethylenic double bond, a cationically polymerizable compound such as an epoxy compound, and the like can be typically used. These compounds include monomers, oligomers, and prepolymers. A polymer or the like can be used alone or in combination as appropriate. Representative compounds are various (meth) acrylate compounds which are radically polymerizable compounds. Among the (meth) acrylic ester-based compounds, examples of the compound used at a relatively low molecular weight include polyester (meth) acrylate, polyether (meth) acrylate, (meth) acrylic acid methacrylate, Epoxy (meth) acrylate, urethane (meth) acrylate, and the like.

Examples of the monomer include 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, neopentaerythritol tri (meth) acrylate, dinepentaerythritol hexa (methyl) Acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol Polyfunctional monomers, such as a di (meth) acrylate, can be used suitably. (Meth) acrylate means acrylate or methacrylate.

When the free radiation-curable resin is hardened by an electron beam, a photopolymerization initiator is not required, and when it is hardened by ultraviolet rays, a known photopolymerization initiator is used. For example, in the case of a radical polymerization system, as the photopolymerization initiator, acetophenones, benzophenones, and 9-oxysulfur can be used alone or in combination. Category, benzoin, benzoin methyl ether, etc. In the case of a cationic polymerization system, as the photopolymerization initiator, an aromatic diazonium salt, an aromatic sulfonium salt, an aromatic sulfonium salt, a metallocene compound, a benzoin sulfonate, or the like can be used alone or in combination.

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

In the radiation-hardenable resin, a thermoplastic resin, a thermosetting resin, or the like may be appropriately added in order to adjust appropriate physical properties and the like. Examples of the thermoplastic resin or the thermosetting resin include various types, such as an acrylic resin, a urethane resin, and a polyester resin.

In order to impart light resistance to the hard coat layer and prevent discoloration, strength deterioration, and cracks caused by ultraviolet rays contained in sunlight, it is also preferable to add an ultraviolet absorbent to the free radiation-curable resin. When an ultraviolet absorbent is added, in order to surely prevent the ultraviolet absorber from hindering the hardening of the hard coat layer, it is preferable that the radiation-hardenable resin is hardened by an electron beam. The ultraviolet absorber may be an organic ultraviolet absorber such as a benzotriazole-based compound or a benzophenone-based compound, or an inorganic system such as particulate zinc oxide, titanium oxide, or cerium oxide having a particle diameter of 0.2 μm or less What is necessary is just to select and use a well-known thing, such as an ultraviolet absorber. The addition amount of the ultraviolet absorber is about 0.01 to 5% by mass in the free radiation-curable resin composition. In order to further improve light resistance, it is preferable to use a radical scavenger such as a hindered amine radical scavenger in combination with an ultraviolet absorber. In addition, the electron beam irradiation system uses an acceleration voltage of 70 kV to 1 MV and a radiation dose of 5 to 100 kGy (0.5 to 10 Mrad).

(Anti-glare layer)

As the anti-glare layer, a conventionally known one may be appropriately used, and generally, it is formed by 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 a true sphere, ellipse, or the like. Preferably, the particles are transparent. Examples of such fine particles include silica beads as the inorganic fine particles, and resin beads as the 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 are generally added in an amount of 2 to 30 parts by mass, and preferably about 10 to 25 parts by mass based on 100 parts by mass of the resin.

The above-mentioned resin in which the anti-glare agent is dispersed and held is the same as the hard coat layer, and the higher the hardness, the better. Therefore, as the resin, for example, a hardening resin such as a radiation-hardenable resin and a thermosetting resin in the hard coat layer can be used.

The thickness of the anti-glare layer may be set to an appropriate thickness, and is usually about 1 to 20 μm. The anti-glare layer can be formed by appropriately applying various known coating methods. In addition, in the coating liquid for forming the anti-glare layer, in order to prevent precipitation of the anti-glare agent, it is preferable to appropriately add a known anti-settling agent such as silicon oxide.

(Anti-reflection layer)

As the anti-reflection layer, a conventionally known one may be appropriately 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 (higher than the low-refractive index layer) alternately adjoining the laminated layer, and the surface side is the low-refractive index layer Of multiple layers. Each thickness of the low-refractive index layer and the high-refractive index layer need only be appropriate thicknesses for the respective applications. It is preferable that each of the thicknesses is about 0.1 μm when adjacent layers are stacked, and about 0.1 to 1 μm when there is only a low-refractive index layer.

Examples of the low refractive index layer include a layer containing a low refractive index substance such as silicon oxide and magnesium fluoride, a layer containing a low refractive index resin such as a fluorine-based resin, and a low refractive index resin. Middle layer, thin film formed by a thin film formation method (e.g., physical or chemical vapor deposition method such as evaporation, sputtering, CVD, etc.) of a layer containing a low refractive index substance such as silicon oxide, magnesium fluoride, etc. The sol solution forms a film formed by a sol-gel method of a silica gel film, or a layer in which void-containing particles as a low refractive index substance are contained in a resin.

The above-mentioned void-containing particles refer to particles containing gas inside, gas-containing porous structure particles, etc., ie, particles having a reduced apparent refractive index as a whole due to voids generated by the gas relative to the original refractive index of the solid portion of the particle. Examples of such void-containing fine particles include silicon oxide fine particles disclosed in Japanese Patent Application Laid-Open No. 2001-233611. As the void-containing fine particles, in addition to inorganic materials such as silicon oxide, hollow polymer fine particles disclosed in Japanese Patent Application Laid-Open No. 2002-805031 and the like can also be mentioned. 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 containing a high refractive index substance such as titanium oxide, zirconia, and zinc oxide in a resin, a layer containing a high refractive index resin such as a fluorine-free resin, and a high refractive index substance. Film in a high-strength resin, a thin film formed by a thin film formation method (such as a physical or chemical vapor deposition method such as vapor deposition, sputtering, CVD, etc.) of a layer containing a high refractive index substance such as titanium oxide, zirconia, and zinc oxide .

(Antistatic layer)

As the antistatic layer, a conventionally known one may be used as appropriate, and generally, it is formed as a layer containing an antistatic layer in a resin. As the antistatic layer, an organic or inorganic compound can be used. For example, as the antistatic layer of the organic compound, a cationic antistatic agent, an anionic antistatic agent, an amphoteric antistatic agent, a nonionic antistatic agent, an organometallic antistatic agent, etc. may be mentioned, and the like 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. Further, as the antistatic agent, for example, conductive fine particles containing a metal oxide can be used. The particle diameter of the conductive fine particles is based on transparency, and for example, the average particle diameter is about 0.1 nm to 0.1 μm. 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.

For the above-mentioned resin containing an antistatic layer, for example, in addition to using a hardening resin such as a radiation-hardenable resin, a thermosetting resin, and the like described in the hard coat layer, an antistatic layer is formed as an intermediate layer. When the surface strength of the antistatic layer is not required, thermoplastics are also used. Sex resin and so on. The thickness of the antistatic layer is only required to be an appropriate thickness, and is usually about 0.01 to 5 μm. The antistatic layer can be appropriately formed using various known coating methods.

When an alignment film is used as a protective film for a polarizer, it is preferable that an antistatic layer is laminated on the 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 laminate two layers. In addition, when assembling an image display device, a polarizing plate protective film is generally used as a processing member on the surface of a polarizing plate (different from a polarizer protective film, which is ultimately not assembled in a liquid crystal display device and is used in a liquid crystal display device manufacturing step A member discarded in the middle), but the polarizing plate protective film is preferably provided with an antistatic layer on one side or the opposite side of the polarizing plate.

(Antifouling layer)

As the antifouling layer, as long as it is well known, conventionally, resins containing silicon-based compounds such as silicone oil and silicone resins; fluorine-based surfactants and fluorine-based compounds such as fluorine-based resins; waxes and the like The coating of the staining agent is formed by a known coating method. The thickness of the antifouling layer is only required to be an appropriate thickness, and it is usually about 1 to 10 μm.

[Example]

Hereinafter, the present invention will be described more specifically with reference to the examples, but the present invention is not limited by the following examples, and can be appropriately modified and implemented within a range that can meet the spirit of the present invention, and all of them are included in Within the technical scope of the present invention.

Evaluation of rainbow spots

In the image display devices 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, and 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, and observe the white image to confirm the presence and extent of rainbow spots, as follows Benchmarks are assessed.

<Evaluation Criteria>

：: No rainbow spot was particularly observed when viewed from the front or obliquely, and the visibility was good.

○: When viewed from the front, no rainbow spot was observed in particular, but when viewed obliquely, a weak rainbow spot was observed, but practically no problem was observed.

×: Rainbow spots were observed from both the front and oblique observations.

<Structure 1 of Video Display Device>

(1) Image display unit: organic EL unit

(2) Visual-side polarizer: A TAC film (manufactured by FUJIFILM Co., Ltd., 80 μm thick) is bonded to the side of the image display unit of the polarizer, which is a protective film on both sides of a polarizer containing PVA and iodine. Polarizing plate made of 1/4 wavelength plate.

(3) Scatter-resistant anti-scattering film: The following alignment films 1 to 5

In addition, the anti-scatter film is bonded to a glass plate via OCA (Optical Clear Adhesive), and the image display device is assembled so that the anti-scatter film becomes the image display unit side.

<Structure of Video Display Device 2>

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

(2) Light source side polarizer: TAC film is provided as a protective film on both sides of a polarizer containing PVA and iodine.

(3) Image display unit: liquid crystal unit

(4) Visible side polarizer: Polarizer with TAC film (manufactured by FUJIFILM Co., Ltd., 80 μm thick) bonded as a protective film on both sides of a polarizer containing PVA and iodine

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

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

Manufacturing example-PET (A)

When the temperature of the esterification reaction tank 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 and 0.064 as catalysts were charged while stirring. Parts by mass of magnesium acetate tetrahydrate, and 0.16 parts by mass of triethylamine. Next, the temperature was increased under pressure, and the pressure esterification reaction was performed 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, the temperature was raised to 260 ° C. in 15 minutes, and 0.012 parts by mass of trimethyl phosphate was added. Next, after 15 minutes, dispersion treatment was performed using a high-pressure disperser. After 15 minutes, the obtained esterification reaction product was transferred to a polycondensation reaction tank, and the polycondensation reaction was performed at 280 ° C under reduced pressure.

After the polycondensation reaction was completed, a filter paper made of Naslon (registered trademark) with a diameter of 5 μm was filtered by 95%, and the filter was extruded into a strand shape from the nozzle. ) 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 substantially no inactive particles and internally precipitated particles were contained. (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, and then fed to an extruder and dissolved at 285 ° C. The polymer was filtered with a filter material of a stainless steel sintered body (95% of particles with a nominal filtering accuracy of 10 μm), extruded into a sheet form from a nozzle, and then wound around a casting drum (surface temperature: 30 ° C.) using an electrostatic casting method casting drum), and cooled and solidified to form an unstretched film.

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

Alignment film 2

Except for changing the thickness of the unstretched film to a thickness of about 100 μm, a uniaxially oriented alignment film 2 was produced in the same manner as the alignment film 1. Re of the alignment film 2 was 10200 nm, Rth was 13233 nm, and Re / Rth was 0.771.

Alignment film 3

Except that the unstretched film is heated to 105 ° C by a heated roller group and an infrared heater, and then the roller group with a peripheral speed difference is extended 1.5 times in the direction of travel, the same method as that of the alignment film 1 is extended in the width direction. Other than 4.0 times, a biaxially oriented alignment film 3 having a film thickness of about 50 μm was produced in the same manner as the alignment film 1. Re of the alignment film 3 was 3915 nm, Rth was 6965 nm, and Re / Rth was 0.562.

Alignment film 4

A biaxially oriented alignment film 4 having a film thickness of about 38 μm was produced in the same manner as the alignment film 3 except that it extended 3.6 times in the traveling direction and 4.0 times in the width direction. Re of the alignment film 4 is 1178 nm, Rth is 6365 nm, and Re / Rth is 0.185.

Alignment film 5

Except for changing the thickness of the unstretched film to a thickness of about 200 μm, a uniaxially oriented alignment film 5 was produced in the same manner as the alignment film 1. The Re of the alignment film 5 is 20500 nm.

Hysteresis (Re) and thickness direction retardation (Rth) were measured as follows. That is, using two polarizing plates, the orientation major axis direction of the film was obtained, and a rectangle of 4 cm × 2 cm was cut out so that the orientation major axis direction was orthogonal to prepare a measurement sample. For this sample, the refractive index (Nx, Ny) of the two orthogonal axes and the refractive index (Nz) of the thickness direction were obtained using an Abbe refractometer (NAR-4T manufactured by ATAGO), and the two The absolute value of the refractive index difference (| Nx-Ny |) of the axis is taken as the anisotropy (ΔNxy) of the refractive index. The thickness d (nm) of the thin film was measured using an electronic micrometer (Millitron 1245D manufactured by FEINPRUF), and the unit was converted to nm. From the refractive index The product (ΔNxy × d) of the anisotropy (ΔNxy) and the thickness d (nm) of the film was used to determine the hysteresis (Re). In addition, Nx, Ny, Nz, and the thickness d (nm) of the film were calculated in the same manner as the measurement of the hysteresis, and the average value of (△ Nxz × d) and (△ Nyz × d) was calculated to determine 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 an alignment film with a retardation of more than 3000 nm on the viewing side than the viewing side polarizer, even when using an organic EL unit and a liquid crystal cell (except the light source is a cold cathode tube) In the case where any one of them is used as the image display unit, the occurrence of rainbow spots can also be suppressed.

Claims (4)

An image display device comprising: (1) an organic EL unit; (2) a polarizer disposed closer to the visual recognition side than the organic EL unit; and (3) a piece of 3000 nm disposed at the visual recognition side closer to the polarizer. The above-mentioned retardation alignment film with a thickness of less than 150000 nm, the ratio (Re / Rth) of the retardation (Re) to the thickness direction retardation (Rth) of the alignment film is 0.2 or more and 2.0 or less, wherein the alignment film is used as: (i) disposed in A polarizer protective film closer to the visual recognition side than the polarizer; (ii) a polarizing plate on the visual recognition side containing the polarizer as a constituent member is closer to the visual recognition side, and in the case of a touch panel, as a touch panel A base film of a transparent conductive film; (iii) a viewing-side polarizing plate containing the polarizer as a constituent member is closer to the viewing side, and is disposed on the touch panel and the viewing side when a touch panel is present Anti-scattering film between polarizer protective films; or (iv) the viewing-side polarizing plate containing the polarizer as a constituent member is closer to the viewing side, and when there is a touch panel, it is arranged closer to the viewing side than the touch panel Anti-scatter thin Film; however, the image display device does not include an image display device with a translucent mask having a retardation in the plane closer to the viewing side than the polarizer. For example, the image display device of claim 1, wherein the angle between the polarization axis of the polarizer and the alignment main axis of the alignment film is approximately 45 degrees. For example, the image display device of claim 1, wherein the retardation of the alignment film is 6000 nm to 150,000 nm. For example, the image display device of claim 1, wherein the image display device has a touch panel near the viewing side polarizer near the viewing side.