JP2002341138A - Method for manufacturing polarizing plate and liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polarizing plate which hardly incurs dimentional deviation in cutting, axial or positional deviation in sticking, which is obtained by integrating an optical film and a polarizing film with a specified size and which is efficiently formed in a few number of steps and with which a thin and lightweight liquid crystal display device with easily visible display is formed. SOLUTION: In the method for manufacturing a polarizing plate, an optical film (1) constructed by disposing a plurality of rectangular regions (10) having a light emitting means equipped with an optical path converting slope on the one side surface of a long size transparent film so as to locate the direction of sides of the respective regions parallel or vertical to the direction of the long sides of the transparent film and a long size polarizing film (2) having an optic axis in the direction of the long sides are stuck to each other via an adhesive layer so as to locate the directions of the respective long sides in parallel with each other. The laminated body is cut so as to obtain laminated pieces (3) comprising the unit regions. The liquid crystal display device comprises the polarizing plate arranged on at least one side of a liquid crystal cell so that the side having the light emitting means of the optical film is the outer side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a liquid crystal display device which is thin, lightweight, bright, has little image disturbance and is easy to see, by efficiently converting the light incident from the side of the liquid crystal display panel in the viewing direction. The present invention relates to a method for manufacturing a polarizing plate.

[0002]

BACKGROUND OF THE INVENTION Light is incident on the side of a liquid crystal display panel having a polarizing plate formed by bonding an optical film having light emitting means and a polarizing film on the viewing side surface of a liquid crystal cell, and transmitting light within the panel. A reflection type liquid crystal display device for both external light and illumination has been proposed in which the panel is illuminated by reflecting light through the light emitting means (Japanese Patent Laid-Open No. 2000-1).
No. 47499). This realizes a liquid crystal display panel illumination system with an optical film that is much thinner than the conventional sidelight type light guide plate, achieving a reduction in thickness and weight, and uses scattered reflected light for illumination (particularly). Kaihei 5-
No. 158033) to achieve a bright display by increasing the directivity of the illumination light.

Conventionally, in the above-mentioned process of bonding and integrating an optical film and a polarizing film, each of the optical film and the polarizing film is first cut at a predetermined size and angle,
A method has been adopted in which an optical film and a polarizing film are adhered to each single plate. Therefore, there are problems that the number of steps from the cutting to the integration process is large, and that a size shift at the time of cutting, a positional shift at the time of bonding, and a shift of an optical axis easily occur. Misalignment or misalignment of the optical axis causes a decrease in contrast and the occurrence of coloring, and also changes the angle of incidence on the light emitting means, and the emitted light is not directed toward the observer. It greatly decreases.

[0004]

SUMMARY OF THE INVENTION According to the present invention, there is little occurrence of a size shift at the time of cutting, a position shift at the time of bonding, and a shift of an optical axis, and a small number of a predetermined size composed of an integrated film of an optical film and a polarizing film. It can be efficiently formed by the number of processes,
It is an object of the present invention to develop a polarizing plate capable of forming a thin, lightweight, bright, and easy-to-view liquid crystal display device by efficiently changing the optical path of light incident from a side surface of a liquid crystal display panel in a viewing direction.

[0005]

According to the present invention, a plurality of rectangular units having a light emitting means comprising a plurality of concave portions having an optical path changing slope having an inclination angle of 35 to 48 degrees with respect to a film surface are formed into a long unit. On one side of the transparent film, an optical film provided so that the direction of the side of each region is parallel or perpendicular to the long side direction of the transparent film, and a long polarizing film having an optical axis in the long side direction The long side direction is parallel, and the laminated body formed by bonding through an adhesive layer such that the surface having the light emitting means of the optical film is on the outside is cut, and the above-mentioned region unit is formed. A method for producing a polarizing plate, characterized in that a laminated piece is obtained, and a liquid crystal characterized by arranging the polarizing plate on at least one side of a liquid crystal cell such that a side having a light emitting means by an optical film is on the outside. display It is to provide a location.

[0006]

According to the manufacturing method of the present invention, a unit of a predetermined size is collectively bonded using a long optical film and a polarizing film, thereby bonding each single plate cut to a predetermined size. The processing can be avoided, and the unit body is less likely to be displaced or displaced in the optical axis, and is also less likely to be displaced in size during cutting. As a result, it is possible to efficiently form a polarizing plate of a predetermined size composed of an adhesive integrated product of an optical film and a polarizing film with a small number of steps and with little variation in quality. Further, by using the polarizing plate, the light incident from the side surface of the liquid crystal display panel is efficiently converted in the viewing direction to form a thin, lightweight, bright, and easy-to-view liquid crystal display device.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The manufacturing method according to the present invention is directed to a method of forming a plurality of units each having a rectangular region having a light emitting means having a plurality of concave portions having an optical path changing slope having an inclination angle of 35 to 48 degrees with respect to a film surface. On one side of a long transparent film,
An optical film provided such that the direction of the side of each region is parallel or perpendicular to the long side direction of the transparent film, and a long polarizing film having an optical axis in the long side direction, and a long side direction thereof. Are cut in parallel, and the laminated body bonded via an adhesive layer such that the surface having the light emitting means of the optical film is on the outside is cut out, and the polarizing plate as a laminated piece composed of the above-mentioned area unit is cut. Is what you get.

FIG. 1 shows a process example of the above-mentioned manufacturing method. FIG. 2 shows an example of the optical film. Further, FIGS. 3 and 4 show examples of concave portions forming the light emitting means. 1 is an optical film (a long transparent film), 10 is its rectangular region, 2 is a polarizing film, A is a concave portion, and a is its optical path conversion slope. 1 is a perspective view, FIG. 2 is a plan view,
3 and 4 are side views showing cross sections of the concave portion with respect to the optical path changing slope. 3 and 4, 1C is an adhesive layer, 1D
Is a polarizing film layer.

A rectangular area 10 in the optical film 1
As shown in FIG. 8, the light emitting means is arranged so that the surface on which the light emitting means is formed is located outside in the direction along the cell plane of the liquid crystal cell having the light source 51 on the side surface. The transmission light is reflected via the optical path changing slope a to be changed in the optical path in the back side (the polarizing film layer side), that is, in the viewing direction of the liquid crystal display panel, and emitted from the polarizing film layer 1D. It is intended to be able to be used as illumination light (display light).

The long transparent film forming the optical film can be formed by using one or more kinds of appropriate materials exhibiting transparency in accordance with the wavelength range of light incident through a light source or the like. it can. Incidentally, in the visible light region, for example, acrylic resins, polycarbonate resins, transparent resins represented by cellulose resins, norbornene resins, and the like, and curable resins that can be polymerized by heat, ultraviolet rays, radiation such as electron beams, and the like. . “Long” means that the length of one side in two directions perpendicular to the thickness direction of the film is larger than the other side (the same applies hereinafter).

The preferred refractive index of the transparent film is equal to or higher than that of the liquid crystal cell, especially the cell substrate, in order to obtain a liquid crystal display device which is bright and has excellent uniformity by increasing the efficiency of incidence on the light path conversion slope. 1.49 or more, especially 1.52
That is all. From the viewpoint of suppressing surface reflection in the case of a front light system, the refractive index is preferably 1.6 or less, more preferably 1.56 or less, and particularly preferably 1.54 or less.
Note that such a refractive index is generally based on the D line in the visible light range, but is not limited to the above when the wavelength range of the incident light has specificity, and is not limited to the above. Can also be used (the same applies hereinafter)

Further, a transparent film which is preferable from the viewpoint of suppressing a luminance nonuniformity and a color nonuniformity to obtain a liquid crystal display device with a small display nonuniformity, does not exhibit birefringence or has a small birefringence. It is 30 nm or less. When a transparent film having a small phase difference is used, when linearly polarized light is incident through a polarizing film layer or the like, the polarization state can be favorably maintained, which is advantageous in preventing deterioration in display quality.

From the viewpoint of preventing display unevenness, the preferable average retardation in the plane of the transparent film is 20 nm or less, preferably 15 nm or less.
It is more preferably 10 nm or less, particularly 10 nm or less, and the variation of the phase difference at each location is as small as possible. Further, a transparent film made of a material having a small photoelastic coefficient is preferable from the viewpoint of suppressing the internal stress which is easily generated in the transparent film by the bonding treatment and preventing the occurrence of a phase difference due to the internal stress. In addition, the average retardation in the thickness direction of the transparent film is preferably 50 nm or less, more preferably 30 nm or less, and particularly preferably 20 nm or less from the viewpoint of preventing display unevenness and the like.

The formation of such a low retardation transparent film is as follows:
For example, it can be performed by an appropriate method such as a method of removing internal optical distortion by a method of annealing an existing film or the like. A preferred forming method is a method of forming a transparent film having a small retardation by a casting method. The above-mentioned retardation in the transparent film is preferably based on light in the visible region, particularly light having a wavelength of 550 nm. The above-mentioned average retardation in the plane is defined by (nx−ny) × d, and the average retardation in the thickness direction is ｛(nx + ny) / 2.
−nz｝ d. Where nx is the average refractive index in the direction showing the maximum refractive index in the film plane, ny
Is the average refractive index in the direction orthogonal to the nx direction in the film plane, nz is the average refractive index in the thickness direction of the film,
d means the average thickness of the film.

The transparent film is usually formed as a single layer, but may be formed as a laminate made of the same or different materials. The thickness of the transparent film can be appropriately determined and is not particularly limited, but is preferably 5 to 500 μm, more preferably 10 to 300 μm, particularly 20 to 10 from the viewpoint of thinning and weight reduction.
0 μm is preferred. With such a thickness, sizing by punching or the like can be easily performed.

As shown in FIG. 2, the optical film includes a plurality of units each having a rectangular area 10 having a light emitting means for obtaining the above-mentioned emission characteristics, on one surface of the transparent film 1.
It is formed by providing the side of each region so as to be parallel or perpendicular to the long side direction (arrow) of the transparent film. The setting of such a parallel or vertical relationship is such that when a long polarizing film having an optical axis in the long side direction and an optical film are bonded so that their long side directions are parallel, the side of the rectangular region 10 Is directed parallel or perpendicular to the optical axis of the polarizing film. It is preferable that the parallel or vertical relationship between the sides of the above-described region is the same in all the rectangular regions provided on the transparent film.

The size of each rectangular area can be appropriately determined according to the size of the liquid crystal cell to be applied. It is preferable to provide rectangular regions having a uniform size at regular intervals, rather than efficiently cutting by a punching method or the like. The rectangular area may be substantially a quadrilateral, and the intersection of the sides may be a right angle, or may be in a non-right angle state after being subjected to a rounding process or the like.

The light emitting means provided in the rectangular area of the optical film (transparent film) includes a concave portion A having an optical path changing slope a having an inclination angle θ1 of 35 to 48 degrees with respect to the film surface as shown in FIGS. Are formed. By the way, in the example of FIG. 3, it is formed of a concave portion having an isosceles triangular cross section and has two optical path changing slopes a. On the other hand, in the example of FIG. 4, the optical path changing slope a having the inclination angle θ1 with respect to the film surface of 35 to 48 degrees.
And a concave portion having a substantially triangular cross section having an upright surface b having a large inclination angle θ2. The concave means that the optical film is concave (groove).

As described above, the incident light or the transmitted light from the side direction by the light source disposed on the side surface of the liquid crystal cell or the like is transmitted through the optical path changing slope a to the back side of the transparent film having no light emitting means, that is, to the polarizing film layer side. By changing the optical path, light having excellent directivity in the normal direction to a liquid crystal cell or the like can be emitted from the transparent film with good use of light from the light source and can be incident on the polarizing film layer. If the inclination angle of the optical path conversion slope is less than 35 degrees, when a reflection plate is disposed on the viewing back side of the liquid crystal cell to reflect the optical path conversion light, display light based on the reflected light is emitted from the liquid crystal display panel. Angle is 30
Exceeding the degree will be disadvantageous for visual recognition. On the other hand, if the angle of inclination of the optical path changing slope exceeds 48 degrees, light is likely to leak from the slope without being totally reflected and the light use efficiency is reduced.

In the above case, when the reflection method using the light path changing slope is used instead of the reflection method using the light emitting means having a roughened surface, the light is hardly reflected in the vertical direction and is inclined more greatly than the front direction from the liquid crystal display panel. The light is emitted in the direction, and the liquid crystal display becomes dark and the contrast becomes poor. Efficient total reflection through the optical path conversion slope, emits light with good directivity from the back of the transparent film in the normal direction of the film surface, and efficiently illuminates the liquid crystal cell to achieve a bright and easy-to-view liquid crystal display. Is preferably 3
8 to 45 degrees, especially 40 to 43 degrees.

The light emitting means can be formed as a plurality of concave portions which are continuous from one side to the other side, or which are discontinuously intermittent as shown in plan views in FIGS. The recesses may be distributed in parallel as in the example of FIG. 5 or irregularly as in the example of FIG. 6, based on the optical path conversion slope in the continuous or discontinuous state described above. Alternatively, the distribution may be arranged in a pit shape with respect to the virtual center as in the example of FIG. Further, the concave portion may have an appropriate form such as a substantially triangular shape to a substantially pentagonal shape based on a cross section with respect to the optical path conversion slope. Generally, the recess is formed in a substantially triangular cross section as shown in the examples of FIGS. Note that "substantially" such as the above-mentioned triangular shape means that a change such as a change in the angle of a side or a circularization of an angle formed by the intersection of the sides is permitted.

The arrangement state of the plurality of concave portions can be appropriately determined according to the form or the like. As described above, the light path conversion slope a is configured to reflect the incident light from the side direction by the light source in the illumination mode toward the rear surface of the transparent film to change the light path. Distributing the light on one side of the transparent film so that the total light transmittance is 75 to 92% and the haze is 4 to 20% can efficiently illuminate the liquid crystal cell by changing the light path from the side direction through the light source. This is preferable from the viewpoint of obtaining a bright surface light source and achieving a liquid crystal display which is bright and has excellent contrast. Such characteristics of the total light transmittance and the haze can be achieved by controlling the size, distribution density, etc. of the concave portions. / 100-1/8, especially 1
/ 50 to 1/10, especially 1/30 to 1/15.

More specifically, if the size of the optical path conversion slope is large, the existence of the slope is easily recognized by the observer, so that the display quality is greatly reduced, and the uniformity of illumination of the liquid crystal cell is also easily reduced. In consideration of the above, when the continuous concave portions are distributed in parallel as in the example of FIG. 5, the repetition pitch is set to 2 mm or less, particularly 20 μm to 1 mm, particularly 50 to 500 μm, and the projection width of the optical path conversion slope to the film surface is adjusted. 40 μm or less, especially 3 to 20 μm, especially 5 to
It is preferably 15 μm. The parallel distribution of the continuous concave portions may be parallel to one side of the rectangular region, or may be arranged in an intersecting state within 30 degrees. The latter is effective for preventing moiré due to interference with the pixels of the liquid crystal cell. The prevention of moire can also be performed by adjusting the repetition pitch of the parallel arrangement, and therefore, the repetition pitch may be changed or may not be constant.

On the other hand, when discontinuous concave portions are distributed in parallel or irregularly as in the examples of FIGS. In consideration of the reflection efficiency by the conversion slope, it is preferable that the length of the optical path conversion slope is 5 times or more, more preferably 8 or more, especially 10 or more, of the depth of the recess. The length of the optical path conversion slope is 500 μm or less, particularly 200 μm or less, and particularly 1 μm or less.
0 to 150 μm, depth and width of concave portion are 2 μm to 100 μm
m, preferably 5 to 80 μm, particularly preferably 10 to 50 μm. The length is based on the length in the long side direction of the optical path conversion slope, that is, the continuous direction of the grooves of the concave portions, and the depth is based on the light emitting means forming surface of the transparent film. The width is based on the length in a direction orthogonal to the long side direction and the depth direction of the optical path conversion slope.

The surface on which the concave portion is formed and which does not satisfy the light path changing slope a having a predetermined inclination angle, for example, the upright surface b facing the light path changing slope a in FIG. It does not contribute to emission from the back surface, and preferably does not affect display quality, light transmission or light emission as much as possible. Incidentally, when the inclination angle θ2 of the upright surface with respect to the film surface is small, the projected area with respect to the film surface becomes large, and in the external light mode by the front light system in which the polarizing plate 3 is arranged on the viewing side as illustrated in FIG. The reflected light returns to the viewing direction, which tends to impair the display quality.

Therefore, it is more advantageous that the inclination angle θ2 of the upright surface or the like is larger, so that the projection area with respect to the film surface can be made smaller and the reduction of the total light transmittance can be suppressed. The angle can be made smaller, the surface reflected light can be reduced, and the reflected light can be inclined in the plane direction of the polarizing plate (the film surface direction), so that the influence on the liquid crystal display can be suppressed. From such a point, a preferable inclination angle θ2 of the upright surface or the like is 50 degrees or more, particularly 60 degrees or more, particularly 75 to 90 degrees.
Degrees.

The slope forming the concave portion A may be formed in an appropriate surface such as a straight surface, a refraction surface, a curved surface, or the like. Further, the cross-sectional shape of the concave portion may be such that the inclination angle or the like is constant over the entire surface of the sheet, or the uniformity of the light emission on the polarizing plate may be taken into account by the absorption loss and the attenuation of the transmitted light due to the optical path conversion. The concave portion may be made larger as the distance from the side surface on which light is incident is increased for the purpose of realizing the structure. In addition, it is also possible to form concave portions having a constant pitch, or to increase the distribution density of concave portions by gradually narrowing the pitch as the distance from the side on which light is incident (arrow) as shown in the examples of FIGS. You can also. Furthermore, the light emission on the polarizing plate can be made uniform at a random pitch, and the random pitch is more advantageous than the prevention of moire due to interference with pixels. Therefore, the light emitting means may be formed of a combination of recesses having different shapes and the like in addition to the pitch.

It is preferable that the light path changing slope in the concave portion faces the direction (arrow) of light to be incident from the side of the liquid crystal cell as shown in the examples of FIGS. Therefore, when a linear light source is used, it is preferable that the optical path conversion slope is oriented in a direction with respect to one side of the rectangular area or in a fixed direction as illustrated in FIGS. When a point light source such as a light emitting diode is used, it is preferable that the optical path conversion slope is oriented in the direction of the light emission center of the point light source as shown in FIG.

The shape of the intermittent end of the concave portion is not particularly limited, but is preferably 30 ° or more, more preferably 45 ° or more, particularly 60 ° or more from the viewpoint of suppressing the influence of the reduction of the incident light on the portion. Preferably, the slope is used. The rectangular area is
It is preferable that the front and back surfaces be as smooth as possible flat surfaces, except for the concave portion forming the light emitting means, and it is particularly preferable that the front and rear surfaces have an angle change of ± 2 degrees or less, particularly 0 degrees. It is preferable that the angle change is within 1 degree per 5 mm in length. By making such a flat surface, most of the film surface forming the rectangular region can be made a smooth surface with an angle change of 2 degrees or less, and the light transmitted inside the liquid crystal cell can be efficiently used to form an image. Uniform light emission without disturbing can be achieved. It is more preferable than the point of easy adhesion to the polarizing film.

As described above, the recess A as illustrated in FIG.
The pit-like arrangement is such that a point light source is disposed on the side surface of a liquid crystal display panel or the like, and the radial incident light or the transmitted light from the side direction by the point light source is converted into an optical path through an optical path conversion slope a to form a polarizing plate. It is an object of the present invention to emit light as uniformly as possible, and to emit light having excellent directivity in a normal direction to a liquid crystal cell or the like from a polarizing plate with efficient use of light from a light source. Therefore, the pit-like arrangement is preferably performed such that a virtual center is formed on the end face of the polarizing plate or outside thereof so that the point light source can be easily arranged. The virtual center can be formed at one position or at two or more positions with respect to the same or different end faces of the polarizing plate.

The optical film is formed, for example, by transferring a transparent film made of a thermoplastic resin under heating to a mold capable of forming one or a plurality of rectangular regions having predetermined light emitting means under heat. A method of filling a heat-melted thermoplastic resin or a resin fluidized through heat or a solvent into a mold capable of forming one or a plurality of rectangular regions having predetermined light emitting means, heat or ultraviolet rays A suitable method such as a method of filling or casting a liquid resin which can be polymerized by radiation such as an electron beam into a mold capable of forming one or more rectangular regions having a predetermined light emitting means and polymerizing the resin. Can be done in a way. The above method is particularly advantageous for forming a transparent film integrally having a rectangular region provided with a light emitting means by forming a transparent film integrally with the rectangular area provided with the light emitting means.

A preferred method of forming a transparent film having a rectangular region provided with light emitting means is, for example, to apply a curable resin which can be polymerized by ultraviolet rays or radiation or the like to one side of the transparent film, and to coat the coating layer with gold. A method of peeling and recovering the transparent film from the mold after curing by irradiation with ultraviolet light or radiation, etc. Filling the surface of the rectangular area provided with light emitting means, forming a transparent film in close contact with the filling layer, curing the filling layer by irradiating ultraviolet rays or radiation, and then peeling the transparent film from the mold This is a method of adding a rectangular area provided with a light emitting means to one surface of a transparent film via a mold capable of forming a rectangular area provided with a predetermined light emitting means, such as a collecting method. Therefore, in this case, as shown in the examples of FIGS. 3 and 4, a transparent film 1B provided with a light emitting means forming layer 1A separately from the transparent film 1B is formed.

In the above-mentioned method of adding a light emitting means forming layer to the transparent film, if the refractive index difference between the light emitting means forming layer to be added and the transparent film is large, the emission efficiency is greatly reduced due to interface reflection and the like. In some cases, it is preferable to minimize the difference in the refractive index between the transparent film and the light emitting means forming layer, from the viewpoint of preventing such a case, preferably within 0.10, particularly preferably within 0.05. In that case, it is preferable to increase the refractive index of the light emitting means forming layer to be added, as compared with the transparent film, from the viewpoint of emission efficiency. In forming the light emitting means forming layer, an appropriate transparent material according to the wavelength range of the incident light can be used according to the transparent film.

In the above, when the mold is capable of forming one or a plurality of rectangular regions having light emitting means,
By repeating the above operation using the mold, an optical film having a predetermined number (plurality) of rectangular regions can be formed. In addition, in the examples of FIGS. 3 and 4, the light emitting means forming layer 1A is provided on the transparent base film 1B, but the light emitting means forming layer in which the base film is omitted as described above is a single layer. It may be a transparent film made of an object.

On the light emitting means forming surface in the rectangular area of the optical film, if necessary, non-glare treatment or anti-reflection treatment for the purpose of preventing visual obstruction due to surface reflection of external light, and hardware for the purpose of scratch prevention A coating treatment or the like can be performed. A polarizing plate having a rectangular region subjected to such a treatment can be preferably used particularly for a front light system. The non-glare treatment can be performed by forming a fine uneven structure on the surface by various methods such as a roughening method such as a sand blast method or an embossing method, and a coating method of a resin containing the above-described transparent particles such as silica. it can. The antireflection treatment can be performed by a method of forming a coherent vapor deposition film. Further, the hard coat treatment can be performed by a method of applying a hard resin such as a curable resin. The non-glare treatment, the anti-reflection treatment, and the hard coat treatment can also be applied to a method of bonding a film which has been subjected to one or more kinds of the treatment.

As shown in FIGS. 1, 3 and 4, the polarizing plate is composed of an optical film 1 and a long polarizing film 2 having an optical axis (arrow) in the long side direction. In this manner, the optical film is bonded via the adhesive layer 1C so that the surface having the light emitting means of the optical film is on the outside, and the laminated body is cut.
(Polarizing plate).

Any suitable polarizing film can be used without any particular limitation. Rather than obtaining a display with a good contrast ratio due to the incidence of highly linearly polarized light, for example, a highly hydrophilic film such as a polyvinyl alcohol-based film, a partially formalized polyvinyl alcohol-based film, or an ethylene-vinyl acetate copolymer-based partially saponified film is used. Those having a high degree of polarization, such as an absorption type polarizing film formed by stretching a molecular film by adsorbing a dichroic substance such as iodine or a dichroic dye, can be preferably used.

The polarizing film to be used may be a film provided with a transparent protective layer according to the prior art on one or both sides thereof. For the formation of the transparent protective layer, those having excellent transparency, mechanical strength, heat stability, moisture shielding property and the like and having a refractive index similar to that of the above-mentioned transparent film are preferably used. Therefore, the optical film can be provided so as to also serve as the transparent protective layer of the polarizing film. In this case, the liquid crystal display device and the like can be made thinner and lighter.

An adhesive layer for adhering the optical film and the polarizing film can be provided on one or both adhesion-treated surfaces of the films. The bonding through the bonding layer is performed by the light path changing slope a of the concave portion A forming the light emitting means.
The purpose of the present invention is to improve the reflection efficiency through the light source, and furthermore to improve the luminance by effectively utilizing the incident light from the side. It is preferable that the adhesive layer has a small difference in the refractive index from the transparent film from the purpose. An adhesive layer that is preferable from the viewpoint of suppressing the total reflection and increasing the incidence efficiency of the liquid crystal cell transmission light into the rectangular region and obtaining a liquid crystal display device that is bright and has excellent uniformity,
It has a refractive index of 0.07 or more lower than that of the transparent film, and has a refractive index higher or close to that of the cell substrate of the liquid crystal cell.

Incidentally, when the refractive index is lower than that of the cell substrate of the liquid crystal cell, the incident light from the side surface is liable to be totally reflected during the transmission. As the cell substrate, a resin plate or an optical glass plate is usually used. In the case of a non-alkali glass plate, the refractive index is 1.
Since about 51 to 1.52 is generally used, ideally, most of the transmitted light having an angle that can be incident on the rectangular region from the cell is obtained by performing an adhesive treatment via an adhesive layer having a higher refractive index. The light can be incident on the rectangular area without being totally reflected at the bonding interface. The light transmission type optical layer such as an adhesive layer, a liquid crystal cell, or a transparent film is improved in terms of the display brightness and the uniformity of the in-plane brightness by suppressing the loss light amount that cannot be emitted by the confinement effect based on total reflection. The preferred refractive index difference at each interface between is within 0.15, especially within 0.10,
In particular, it is within 0.05. Therefore, the preferable refractive index of the adhesive layer is 1.49 or more, preferably 1.50 or more, particularly 1.51 or more.
That is all.

For forming the adhesive layer, an appropriate material such as an adhesive which is cured by irradiation with ultraviolet rays or radiation or by heating can be used without any particular limitation. The pressure-sensitive adhesive layer can be preferably used from the viewpoint of easy handling such as easy adhesion and stress relaxation property for suppressing generation of internal stress. For forming the adhesive layer, for example, an adhesive using a suitable polymer such as a rubber-based, acrylic-based, vinyl alkyl ether-based, silicone-based, polyester-based or polyurethane-based, polyether-based, polyamide-based, or styrene-based polymer as a base polymer Etc. can be used. Among them, those excellent in transparency, weather resistance, heat resistance and the like, such as an acrylic pressure-sensitive adhesive having a polymer mainly composed of an alkyl ester of acrylic acid or methacrylic acid as a base polymer, are preferably used.

The adhesive layer may be formed of inorganic particles which may be conductive, such as silica, alumina, titania, zirconia, tin oxide, indium oxide, cadmium oxide, nonmonoxide, or organic such as crosslinked or uncrosslinked polymers. One or more suitable transparent particles such as system particles may be contained to form a light diffusion type.

In the case of forming a laminate with an optical film, the optical axis in the long side direction of the polarizing film is generally an absorption axis, but is not limited to this, and may be a transmission axis. Also, the bonding process between the optical film and the polarizing film
It can be performed by an appropriate method. Generally, since the light emitting means is formed of a concave portion and is less likely to be crushed, a continuous bonding method using the pressure rollers 4, 5 as shown in the example of FIG. 1 is preferable from the viewpoint of manufacturing efficiency and the like. In addition, the light emitting means having the concave portion has the advantage of being excellent in light incidence efficiency and the like in addition to being excellent in preventing damage as described above, as compared with the convex shape.

The purpose of cutting the laminate of the optical film and the polarizing film is to cut out a rectangular area of the optical film from the laminate for each unit and obtain a polarizing plate 3 composed of a laminated piece as a unit body. I do. The cutting process is
An appropriate method such as a punching method can be used. Also, the cutting process can be performed in a separate step from the formation of the laminate, or a cutting device is provided after the bonding device to continuously form the laminate and sequentially perform the cutting process simultaneously with the laminate to obtain a polarized light. It is also possible to adopt a method of continuously manufacturing plates.

In the above-mentioned cutting process, as shown in FIG. 2, a plurality of rectangular area units 10 in the laminated optical film are provided with an appropriate position specifying mark such as a cross 11 for example. It is also possible to detect the cutting position through the means for recognizing the mark for position identification and cut the laminate. Thus, the cutting position can be determined quickly and accurately, and the uniformity of the cutting shape and quality of the polarizing plate can be improved. The position specifying mark to be formed is arbitrary as described above, and can be provided on one or both of the optical film and the polarizing film forming the laminate. Such a mark can be provided in advance on an optical film or the like before forming a laminate, or can be provided after forming the laminate.

The above-mentioned laminate or polarizing plate may be provided with a transparent adhesive layer on the side of the polarizing film for adhering to another member, if necessary. The adhesive layer can conform to the case of the laminate described above. Further, such an adhesive layer can be provided in advance on the polarizing film before forming the laminate, or can be provided after forming the laminate or the polarizing plate. It is preferable to cover the adhesive layer with a release sheet temporarily for the purpose of preventing entry of foreign matter or the like until the adhesive layer is put to practical use.

The polarizing plate according to the present invention is arranged such that, through the light emitting means (optical path changing slope), the incident light from the side of the light source or the transmitted light from the light source is directed in a direction (normal direction) excellent in perpendicularity, which is advantageous for visual recognition. The light path can be converted to emit light with high utilization efficiency, and it can exhibit good transparency to external light. For example, bright and easy-to-view thin and lightweight reflective or transmissive external light / illumination Various devices such as a dual-purpose liquid crystal display device can be formed. FIG. 8 shows an example of the liquid crystal display device. The figure shows an example of a reflection type liquid crystal display device for both external light and illumination. Reference numerals 20 and 30 denote cell substrates in a liquid crystal cell, 40 denotes a liquid crystal layer, and 31 denotes a reflective layer.

As shown in the drawing, the liquid crystal display device can be formed by disposing the polarizing plate 3 on at least one side of the liquid crystal cell such that the side having the light emitting means is on the outside. In that case, the lighting mechanism is one of the liquid crystal cells as shown in the figure.
Alternatively, it can be formed by arranging one or more light sources 51 on one or more side surfaces of the cell substrate 20 on the side where the polarizing plate 3 is arranged, particularly on two or more side surfaces. In that case, it is preferable to adhere the polarizing plate to a liquid crystal cell or the like via an adhesive layer from the viewpoint of achieving a bright display.

When forming the illumination mechanism, in the case of a polarizing plate having pit-shaped light emitting means as shown in the example of FIG.
It is preferable to arrange the point light source on the side surface of the liquid crystal cell on a vertical line including the virtual center of the pit-shaped arrangement of the light emitting means, in order to achieve a bright display by efficiently using the radial incident light from the point light source. In such an arrangement of the point light sources corresponding to the virtual center, the point light source of the cell substrate 20 as shown in the example of FIG. 8 depends on whether the virtual center of the light emitting means is at the end face of the polarizing plate or outside thereof. An appropriate countermeasure such as a method of protruding the side on which is disposed can be adopted.

As the light source disposed on the side surface of the liquid crystal cell, any suitable light source can be used. For example, in addition to the above-mentioned point light sources such as light emitting diodes, etc., linear light sources such as (cold and hot) cathode tubes, and point light sources An array in which light sources are arranged linearly or in a plane, or a combination of a point light source and a linear light guide plate to convert incident light from the point light source into a linear light source through the linear light guide plate And the like can be preferably used.

The light source is preferably disposed on the side of the cell where the optical path conversion slope of the polarizing plate faces, from the viewpoint of emission efficiency. By arranging the optical path conversion slope so as to face the light source as perpendicularly as possible, including the case of the above-mentioned pit-shaped arrangement, efficiently convert the incident light from the side surface through the light source into a surface light source. Light can be emitted with high efficiency. Therefore, in the case of the rectangular area 10 having two optical path changing slopes a as in the example of FIG. 3, light sources can be arranged on both of the opposed side surfaces of the cell substrate. In the case of a pit-like arrangement, a point light source can be arranged at one or more places corresponding to the virtual center of the light emitting means on the polarizing plate.

The light source enables visual recognition in the illumination mode by lighting the light source. In the case of a liquid crystal display device for both external light and illumination, it is necessary to light the light source when the visual light is viewed in the external light mode using external light. Since there is no such switch, it can be switched between ON and OFF. An arbitrary method can be adopted as the switching method, and any of the conventional methods can be adopted. Note that the light source may be of a different color emission type capable of switching emission colors, or may be of a type capable of emitting different colors through different types of light sources.

As shown in the example of FIG. 8, the light source 51 is a combination body in which appropriate auxiliary means such as a reflector 52 surrounding the liquid crystal cell are arranged in order to guide divergent light to the side surface of the liquid crystal cell as necessary. Can also. As the reflector, an appropriate reflection sheet such as a resin sheet, a white sheet, or a metal foil provided with a high-reflectance metal thin film can be used. The reflector is
The end can be bonded to the end of a cell substrate or the like, and can be used as a fixing means that also serves as a surrounding of the light source.

In general, a liquid crystal display device comprises a liquid crystal cell functioning as a liquid crystal shutter, a driving device associated therewith, a front light or a backlight (polarizing plate) and, if necessary, components such as a reflective layer and a compensating retardation plate. Are formed by appropriately assembling them. In the present invention, there is no particular limitation except that an illumination mechanism is formed by using the above-described polarizing plate and light source, and it can be formed according to a conventional front light type or backlight type. Therefore, the liquid crystal cell to be used is not particularly limited, and the liquid crystal 40 is sealed between the cell substrates 20 and 30 via the sealing material 41 as shown in the figure,
Appropriate reflective or transmissive devices that can obtain display light through light control by the liquid crystal or the like can be used.

Incidentally, specific examples of the above-mentioned liquid crystal cell include twisted and non-twisted types such as TN type liquid crystal cell, STN type liquid crystal cell, IPS type liquid crystal cell, HAN type liquid crystal cell, OCB type liquid crystal cell and VA type liquid crystal cell. System, a guest host system or a ferroelectric liquid crystal system, or a light diffusion type liquid crystal cell such as an internal diffusion system. The liquid crystal driving method may be an appropriate one such as an active matrix method or a passive matrix method. The driving of the liquid crystal is usually performed via electrodes 21 and 31 provided inside the cell substrate as in the example of FIG.

In the reflection type liquid crystal display device, the arrangement of the reflection layer is indispensable, and the arrangement position can be provided inside the liquid crystal cell as illustrated in FIG. 8 or outside the liquid crystal cell. it can. Therefore, in the example of FIG.
Also serves as a reflective layer. For the reflective layer, for example, a coating layer containing a powder of a high-reflectance metal such as aluminum, silver, gold, copper, or chromium in a binder resin, an attached layer of a metal thin film formed by a vapor deposition method, or the like; Sheet, a metal foil, a transparent conductive film, a dielectric multilayer film or the like, which is supported by a base material, and can be formed as an appropriate reflective layer according to the related art.
When a transmissive liquid crystal display device is used for both external light and illumination, the reflective layer disposed outside the polarizing plate can be appropriately formed in accordance with the above.

On the other hand, a transmission type liquid crystal display device can be formed by disposing a polarizing plate on the viewing back side of a liquid crystal cell. In this case, by providing a reflective layer on the back side (outside) of the light emitting means, light leaking from an optical path changing slope or the like is reflected and returned to the direction of the liquid crystal cell, so that it can be used for cell illumination and the luminance can be improved. it can. At this time, by using the reflection layer as a diffuse reflection surface, the reflected light can be diffused and directed in the front direction, and can be directed in a more effective direction by visual recognition. Further, by providing the above-mentioned reflective layer, it can be used as a transmissive liquid crystal display device of both external light and illumination type.

When the reflective layer is disposed outside the liquid crystal cell in the above, the cell substrate and the electrodes need to be formed as transparent substrates and transparent electrodes in order to enable liquid crystal display. On the other hand, when an electrode 31 serving also as a reflection layer is provided inside the liquid crystal cell as in the example of FIG. 8, the cell substrate 20 and the electrode 21 on the viewing side are provided to enable liquid crystal display.
Need to be formed as a transparent substrate or a transparent electrode, but the cell substrate 30 on the back side does not need to be transparent like the reflective layer 31, and may be formed of an opaque body.

The thickness of the cell substrate is not particularly limited, and can be appropriately determined according to the sealing strength of the liquid crystal, the size of the light source to be arranged, and the like. Generally, 10 μm to 5 mm, especially 50 μm to 2 in consideration of the balance between light transmission efficiency and thinness and lightness.
mm, especially 100 μm to 1 mm. Further, the thickness of the cell substrate may be different between the side where the light source is disposed and the side where the light source is not disposed, or may be the same thickness.

In forming a liquid crystal cell, FIG.
As shown in the example, alignment films 22, 32 such as a rubbing film for aligning liquid crystal, a color filter 23 for realizing color display, a low refractive index layer 24, a retardation plate 25, and the like can be provided. In general, the alignment film is disposed adjacent to the liquid crystal layer, and the color filter is disposed between the cell substrate and the electrode. For the purpose of controlling the display light via the linearly polarized light, a polarizing film can be arranged on the side of the liquid crystal cell having no polarizing plate according to the present invention, if necessary. Therefore, the polarizing plate or the polarizing film can be arranged at an appropriate position on one or both of the viewing side and the back side of the liquid crystal cell.

The low-refractive-index layer reflects the light incident from the side surface direction through the light source at the interface and efficiently transmits the light rearward in the direction away from the light source. The objective is to improve the uniformity of brightness on the entire surface of the cell display by efficiently entering the light. The low-refractive-index layer can be formed as a transparent layer made of an appropriate low-refractive-index material made of an inorganic substance or an organic substance such as a fluorine compound, and the arrangement position is inside the cell substrate 20 where the light source 51 is arranged as in the example of FIG. The surface of the substrate opposite to the side where the polarizing plate is provided is preferable from the viewpoint of improving the brightness of the cell display. In addition, the refractive index is lower than that of the cell substrate.
01 or more, especially 0.02 to 0.15, especially 0.05 to
The low refractive index layer having a low refractive index of 0.10 is preferable from the viewpoint of improving the brightness of the cell display.

When forming the liquid crystal display device, a liquid crystal display panel is provided, where necessary, in addition to the above-mentioned non-glare layer or the like, one or more appropriate optical layers such as a light diffusion layer and a retardation plate are added. You can also. The light diffusion layer aims at expanding the display range by diffusion of display light, making the luminance uniform by leveling light emission, and increasing the amount of light incident on the polarizing plate by diffusion of transmission light in the liquid crystal cell. The additional optical layer may be laminated and integrated with a polarizing plate via an adhesive layer or the like, if necessary, and applied to a liquid crystal cell.

The light diffusion layer can be provided by an appropriate method using a coating layer or a diffusion sheet having a fine surface unevenness structure according to the non-glare layer. The light diffusing layer can also be arranged as a layer also serving as an adhesive layer by blending transparent particles into the adhesive layer, thereby making it possible to reduce the thickness of the liquid crystal display device. One or two or more light diffusion layers can be disposed at appropriate positions such as between the polarizing plate and the cell substrate on the viewing side.

The above-mentioned retardation plate is usually disposed between the polarizing plate or the like on the viewing side and / or the rear side and the cell substrate as shown in FIG. 8 for the purpose of expanding the viewing angle and preventing coloring by optical compensation. You. An appropriate retardation plate for compensation may be used according to a wavelength range or the like, and may be formed as a single layer or a superposed layer of two or more retardation layers. The phase difference plate is
A birefringent film obtained by stretching a film made of an appropriate transparent polymer by an appropriate method such as uniaxial or biaxial, an alignment film of an appropriate liquid crystal polymer such as a nematic type or discotic type, and an alignment layer thereof with a transparent base. The heat-shrinkable film may be obtained by controlling the refractive index in the thickness direction under the action of the heat-shrinking force of the heat-shrinkable film.

In the reflection type liquid crystal display device shown in FIG. 8, when the light is used for both external light and illumination, the light emitted from the back surface of the polarizing plate 3 in the illumination mode in which the light source 51 is turned on is indicated by an arrow as shown by an arrow in the drawing. The reflective layer 3 via the cell
After being reflected at 1, the display light that has passed through the inside of the liquid crystal cell to reach the polarizing plate and transmitted from portions other than the concave portion A is visually recognized.
On the other hand, in the external light mode by turning off the light source, the polarizing plate 3
Light incident from a portion other than the concave portion on the light emitting means forming surface of the light-emitting device is reflected through the reflective layer 31, passes through the inside of the liquid crystal cell in the same manner as above, reaches the polarizing plate, and the display light transmitted from the portion other than the concave portion is visually recognized.

On the other hand, in a transmission type liquid crystal display device,
In the visual recognition using both lights, light emitted from the polarizing film layer of the polarizing plate disposed on the rear side enters the liquid crystal cell in the illumination mode in which the light source is turned on, and display light transmitted through the polarizing film or the like is visually recognized. In the external light mode in which the light source is turned off, external light incident from the viewing side surface passes through the liquid crystal cell to reach the polarizing plate, and light incident from a portion other than the concave portion of the light emitting means forming surface is reflected on the rear surface. Flip through layers,
The display light transmitted through the liquid crystal cell in reverse is visually recognized.

In the present invention, the components forming the liquid crystal display device described above may be wholly or partially laminated and integrated and fixed, or may be arranged in an easily separable state. It is preferable to be in a fixed state from the viewpoint of preventing a decrease in contrast by suppressing interface reflection,
It is preferable that at least the polarizing plate and the liquid crystal cell are in a fixed and adhered state. An appropriate transparent adhesive such as a pressure-sensitive adhesive can be used in the fixing treatment, and the transparent adhesive layer can also contain transparent particles and the like to form an adhesive layer having a diffusion function.

The above-mentioned formed parts, especially those on the viewing side, are treated with a UV absorber such as a salicylic acid ester compound, a benzophenone compound, a benzotriazole compound, a cyanoacrylate compound, a nickel complex salt compound, or the like. It can also have ultraviolet absorbing ability.

[0069]

Example 1 An ultraviolet-curable acrylic resin was applied to a long transparent film of polycarbonate (PC) with a thickness of about 100 μm using an applicator on a long transparent film of 60 μm. The layer is brought into close contact with a mold in which the layer has been processed in a predetermined shape so that it is parallel to the long side direction of the film with a rubber roller, and excess resin and air bubbles are extruded. The operation of peeling from the mold is sequentially repeated at a constant interval, and has a plurality of units each including a rectangular area provided with light emitting means at a constant interval on one surface of the long transparent film, and in the long side direction of the transparent film. On the other hand, an optical film was obtained in which the long sides of each region were parallel and the short sides were perpendicular. The measured refractive index of the cured ultraviolet-curable resin was 1.515.

The rectangular area has a width of 30 mm and a length of 40 mm.
mm, a light emitting means comprising a plurality of concave portions in which optical path conversion slopes continuous in the width direction are arranged in parallel in the length direction at a pitch of 210 μm, and a triangle section is formed between the slope and a surface facing the slope. Have The projection width of the optical path changing slope with respect to the film surface is 10 μm, the tilt angle is 42.5 degrees, and the tilt angle of the facing surface is about 75 degrees. Further, the area of the flat surface formed of the portion other than the concave portion on the surface on which the light emitting means is formed is at least 12 times the sum of the optical path conversion slope and the facing surface. Further, when the total light transmittance and the haze of this optical film were measured, each was 89%.
And 7%.

Next, a polyvinyl alcohol-based long polarizing film having an absorption axis in the long-side direction is provided on the optical film through an acrylic adhesive layer having a refractive index of 1.515. Adhering via a pressure roller so as to be parallel and the surface having the light emitting means of the optical film to be outside, and forming a laminated body continuously (FIG. 1), it is disposed after the pressure roller. Each region unit was punched out sequentially through the Thomson blade punching device described above to continuously obtain a polarizing plate composed of the laminated pieces. At the time of the punching, position control was performed by an image recognition system using a television camera and a personal computer to prevent a position shift.

Comparative Example An optical film was formed in the same manner as in Example 1, and the simple substance was punched out sequentially for each area unit. A single polarizing film was punched out into a predetermined size with a Thomson blade according to Example 1. Next, the punched pieces of the optical film and the polarizing film were adhered for each veneer with their respective sides aligned to obtain a polarizing plate according to Example 1.

Evaluation Test The time required to produce 1,000 polarizing plates in the production methods of the examples and comparative examples was examined. The results are shown in the following table. Process required time (minutes) Example Comparative example Set of optical film 15 15 Same as above No cutting 5 Set of polarizing plate 15 15 Same as above No cutting 5 Continuous lamination 3 No Same Same as above 5 No bonding per veneer None 250 Total time required 38 290

From the above table, it can be seen that the time required for manufacturing 1,000 polarizing plates is about 40 minutes in the example, but about 5 hours in the comparative example. In the example, 1000 polarizing plates were actually manufactured, but in the comparative example, the bonding process for each single plate took about 1 hour to bond to 100 polarizing plates, so the required time was increased by 10 times. The time required for the process of bonding to 1,000 polarizing plates was determined.

On the other hand, 30 sheets of each of the polarizing plates obtained in Examples and Comparative Examples were indiscriminately extracted, and the axis shift and the position shift of the optical axis were measured with a microscope. The results are shown in the following table. In the table, X is the average value of the axial deviation and the positional deviation, σ is their standard deviation, and NG is the number of defective products showing an axial deviation of 0.4 degrees or more and a positional deviation of 0.3 mm or more. It is. Example Comparative Example X σ NG X σ NG axis shift 0 0 0 0.1 0.07 1 Position shift 0 0 0 0.2 0.12 2

According to the above table, no axis deviation and no position deviation were observed in the examples, but in the comparative example, the average axis deviation was 0.1 degrees, the position deviation was 0.2 mm, and It can be seen that there are some products that show an axis deviation of 0.4 degrees or more and a positional deviation of 0.3 mm or more and become defective.

In the examples, it was found that if the image recognition system was not used when cutting the laminated body, the cutting position was gradually shifted and a defective product was obtained about 30 minutes after the start. Therefore, when the image recognition system is not used, 3
It is necessary to reset the laminate every 0 minutes, which increases the required time.

[Brief description of the drawings]

FIG. 1 is an explanatory perspective view of a manufacturing process.

FIG. 2 is an explanatory plan view of an optical film.

FIG. 3 is an explanatory side view of a laminate (recess).

FIG. 4 is an explanatory side view of another laminated body (recess).

FIG. 5 is an explanatory plan view of a light emitting unit.

FIG. 6 is an explanatory plan view of another light emitting unit.

FIG. 7 is an explanatory plan view of still another light emitting means.

FIG. 8 is an explanatory side view of a reflective liquid crystal display device.

[Explanation of symbols]

 3: polarizing plate (laminated piece) 1: optical film 10: rectangular area having light emitting means A: concave part a: optical path conversion slope 2: polarizing film 1c: adhesive layer 1D: polarizing film layer 20, 30: cell substrate 40 : Liquid crystal layer 51: light source

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Seiji Umemoto 1-1-2 Shimohozumi, Ibaraki City, Osaka Prefecture Inside Nitto Denko Corporation (72) Inventor Yuki Nakano 1-1-2 Shimohozumi, Ibaraki City, Osaka Prefecture No. Nitto Denko Corporation F term (reference) 2H042 BA05 BA15 BA20 2H049 BA02 BB63 BC13 BC14 BC22 2H091 FA08X FA08Z FA41X FA41Z FB02 FC25 KA10 LA17 LA18

Claims (9)

[Claims] An inclination angle with respect to a film surface is 35 to 48.
A plurality of units each comprising a rectangular region having a light emitting means comprising a plurality of concave portions having a plurality of optical path conversion slopes are provided on one surface of a long transparent film, and the direction of the side of each region is the long side direction of the transparent film. An optical film provided so as to be parallel or perpendicular to the optical film and a long polarizing film having an optical axis in the long side direction such that their long side directions are parallel to each other, and light emission of the optical film. A method of manufacturing a polarizing plate, comprising: cutting a laminate bonded through an adhesive layer such that a surface having the means is on the outside to obtain a laminate piece including the above-described area unit. 2. The method for manufacturing a polarizing plate according to claim 1, wherein the concave portion forming the light emitting means has a substantially triangular shape based on a cross section of the light path changing slope. 3. The optical path changing slope according to claim 2, wherein the length of the concave portion forming the light emitting means in the long side direction is 500.
μm or less, 5 times or more the depth of the concave portion, and the depth of the concave portion is 100 μm or less, and the width of the optical path conversion slope in the direction orthogonal to the long side direction and the depth direction is 100 μm or less. Production method. 4. The method for manufacturing a polarizing plate according to claim 3, wherein a surface of the concave portion forming the light emitting means, which faces the optical path changing slope, has a vertical angle of 60 to 90 degrees with respect to the film surface. 5. A polarizing plate according to claim 1, wherein the concave portions forming the light emitting means are arranged in parallel or irregularly on the basis of the optical path changing slope or in pits with respect to the virtual center. Method. 6. The method according to claim 1, wherein the adhesive layer is an adhesive layer having a refractive index of 1.49 or more. 7. The method for manufacturing a polarizing plate according to claim 1, wherein the laminate has a mark for specifying a position for each of a plurality of rectangular area units in the optical film. 8. The method for manufacturing a polarizing plate according to claim 7, wherein the laminate is cut through a means for recognizing a mark for position identification. 9. A liquid crystal, comprising: a polarizing plate according to claim 1, wherein the polarizing plate is arranged on at least one side of a liquid crystal cell such that a side having a light emitting means by an optical film is on the outside. Display device.