JP2000075283A - Reflective liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a reflective liquid crystal display in which variation of chromaticity of a displayed color, varying according to an outgoing angle of a light based on impartment of a light scattering function of a forward scattering film or the like, is suppressed. SOLUTION: A liquid crystal cell 13 constructed by liquid crystal enclosed between an upper transparent substrate 14 and a lower substrate 19, a polarizing film 11, the first forward scattering film 10a, the second forward scattering film 10b, a birefringence film 12 with retardation located between the second forward scattering film 10b and the polarizing film 11 and being able to suppress variation of a color, varying according to an outgoing angle of a light generated by the liquid crystal cell 13 and the polarizing film 11 and a mirror reflection plate 18 located between the lower substrate 19 and liquid crystal are provided. The second forward scattering film 10b with retardation is made to be able to suppress variation of a color, varying according to an outgoing angle of a light generated by the second forward scattering film 10b itself and the first forward scattering film 10a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reflection type liquid crystal display device.

[0002]

2. Description of the Related Art With the rapid spread of information communication devices such as mobile phones, PHSs, and PDAs (Personal Digital Assistants), an infrastructure that allows anyone to easily access and transmit data regardless of time and place is being prepared. Since these are premised on mobile applications, lightweight, thin, and low power consumption display devices are required, and currently, liquid crystal display devices are mainly used. Liquid crystal display devices perform display by changing the light transmission intensity by driving liquid crystal molecules with an effective voltage of several volts.
Since the liquid crystal is a non-light emitting substance, some other light source is required. It is necessary to supply a very large power to the light source compared to the power for driving the liquid crystal.However, a reflective liquid crystal display device that has a reflective plate below the liquid crystal display device and displays using ambient light Accordingly, it is possible to realize a display device which consumes extremely low power and makes use of the inherent characteristics of liquid crystal. Such a reflection type liquid crystal display device is becoming indispensable as one of displays of a portable information terminal.

However, the reflection type liquid crystal display device has a problem that sufficient brightness cannot be obtained in a direction other than the specular reflection direction of light incident on the display device, since display is performed using ambient light. . Therefore, in order to widen the viewing angle characteristics, a configuration using a scattering film or the like that diffuses light in directions other than the specular reflection direction has been proposed.

[0004] As such a conventional reflection type liquid crystal display device, a device provided with a forward scattering film above a polarizing film, as described in JP-A-8-201802, is known. FIG. 4 shows a conventional reflective liquid crystal display device. As shown in FIG. 4, a conventional reflective liquid crystal display device includes a forward scattering film 10, a polarizing film 11, a birefringent film 12, a liquid crystal cell 13, an upper transparent substrate 14, a color filter 15, a transparent electrode 16, and a liquid crystal layer 17. , A mirror reflector 18 and a lower substrate 19.

Further, as a reflection type liquid crystal display device different from the reflection type liquid crystal display device shown in FIG. 4, a forward scattering film 10 provided above a polarizing film 11 in FIG.
However, there is also known a reflection type liquid crystal display device provided not between the polarizing film 11 but the birefringent film 12 and the upper transparent substrate 14.

[0006]

However, when a forward scattering film 10 having a function of diffusing incoming and outgoing light of a reflection type liquid crystal display device as in the conventional structure is provided, the viewing angle characteristics are widened, but the chromaticity of the display color is increased. However, there is a problem in that the difference greatly depends on the viewing angle direction. That is, the light transmitted through the forward scattering film 10 is diffused at various angles due to the scattering characteristics of the forward scattering film 10, and the chromaticity of the light diffused to each emission angle is different. Thereby, the display of the reflective liquid crystal display device looks colored. Therefore, it becomes necessary to optimize the optical configuration of the reflection type liquid crystal display device again in consideration of substantial coloring by the forward scattering film 10.

The present invention has been made in view of the above circumstances, and provides a reflection type liquid crystal display device in which a variation in chromaticity of a display color, which varies depending on an emission angle of light by providing a light scattering function of a forward scattering film or the like, is suppressed. Aim.

[0008]

To achieve the above object, a first invention (corresponding to claim 1) comprises a first substrate,
A second substrate, and a liquid crystal cell composed of liquid crystal sealed between the first substrate and the second substrate; and a liquid crystal cell opposite to the first substrate with the liquid crystal sealed therein. A polarizing film disposed on the side, one or a plurality of scattering films disposed between the first substrate and the polarizing film, and / or disposed outside the polarizing film, and the first substrate and One or more birefringent layers having retardation, which are arranged anywhere between the polarizing film and the liquid crystal cell and can suppress variations in different colors depending on an emission angle of light generated by the polarizing film. A film, comprising a light reflecting means disposed between the second substrate and the liquid crystal, wherein the scattering film,
A reflective liquid crystal display device having a retardation capable of suppressing variation in different colors depending on an emission angle of light generated by the scattering film itself.

According to a second aspect of the present invention (corresponding to claim 2), the first aspect
Substrate, a second substrate, and the first substrate and the second substrate.
A liquid crystal cell composed of liquid crystal sealed between the first substrate, a polarizing film disposed on the side opposite to the side where the liquid crystal is sealed with respect to the first substrate, and the first substrate One or a plurality of scattering films disposed between the polarizing film and / or outside the polarizing film, and light reflecting means disposed between the second substrate and the liquid crystal. The reflection type liquid crystal display device is characterized in that the scattering film has a retardation capable of suppressing a variation in different colors depending on an emission angle of light generated by the scattering film itself.

[0010] By making the structure of the reflective liquid crystal display device of the first or second aspect of the present invention as described above, the scattering of the chromaticity of the display color due to the provision of the scattering function can be suppressed by the scattering film itself. it can. At the same time, a reflective liquid crystal that diffuses incident light from angles other than the viewing direction and condenses it in the viewing direction increases reflectance, provides an achromatic white display, and achieves higher contrast. A display device can be provided.

A third aspect of the present invention (corresponding to claim 3) is the first aspect of the present invention.
Alternatively, in the reflective liquid crystal display device according to the second aspect of the present invention, a second scattering film, which is arranged on the side opposite to the side where the liquid crystal is sealed with respect to the first substrate and is different from the scattering film, A reflective liquid crystal display device comprising:

According to a fourth aspect of the present invention (corresponding to claim 4), the first aspect
In the reflective liquid crystal display device according to any one of the first to third aspects, the scattering film has a retardation of 20 nm.
A reflective liquid crystal display device characterized by the following.

As described above, when the retardation of the scattering film is 20 nm or less, a change in retardation due to a change in viewing angle can be reduced, and coloring of a display color by providing a scattering function in a wide viewing angle range can be corrected.

[0015] The fifth invention (corresponding to claim 5) is the first invention.
Substrate, a second substrate, and the first substrate and the second substrate.
A liquid crystal cell composed of liquid crystal sealed between the first substrate, a polarizing film disposed on the side opposite to the side where the liquid crystal is sealed with respect to the first substrate, and the first substrate One or more scattering films disposed between the polarizing film and / or outside the polarizing film; and the liquid crystal disposed between the first substrate and the polarizing film. One or more first birefringent films having retardation, and the first substrate and the polarizing film, which can suppress variations in different colors depending on a cell and an emission angle of light generated by the polarizing film. And at least one sheet having retardation that can suppress variations in different colors depending on the emission angle of light generated by the scattering film. A birefringent film a second of a reflective type liquid crystal display device characterized by comprising an arrangement light reflected means between said second substrate crystal.

With this configuration, the scattering of the chromaticity of the display color due to the scattering function can be suppressed by the scattering film itself. At the same time, a reflective liquid crystal that diffuses incident light from angles other than the viewing direction and condenses it in the viewing direction increases reflectance, provides an achromatic white display, and achieves higher contrast. A display device can be provided.

A sixth invention (corresponding to claim 6) is a fifth invention.
In the reflection-type liquid crystal display device of the present invention, a second scattering film different from the scattering film is disposed on one of the side opposite to the side where the liquid crystal is sealed with respect to the first substrate. A reflective liquid crystal display device comprising:

According to a seventh aspect of the present invention (corresponding to claim 7), the sixth aspect
The reflection type liquid crystal display device according to the present invention, wherein the second birefringent film and the second scattering film are integrated.

With this configuration, the function can be separated into a scattering film having a scattering characteristic and a second birefringent film having a chromaticity adjusting function. From this point, individual characteristics can be easily optimized.

According to an eighth aspect of the present invention (corresponding to claim 8), the fifth aspect
The reflective liquid crystal display device according to any one of the first to seventh aspects, wherein the material of the second birefringent film is an acetate-based cellulose.

A ninth aspect of the present invention (corresponding to claim 9) is an eighth aspect of the present invention.
The reflective liquid crystal display device according to the present invention, wherein the acetate-based cellulose is triacetate cellulose.

As described above, when the material of the second birefringent film is an acetate-based cellulose, and particularly when it is a triacetate cellulose, the change in optical properties is very small and stable under various use environments. In addition to exhibiting characteristics, the acetate cellulose is colorless and transparent, so that an optimized optical configuration can be achieved, and an achromatic black-and-white display can be realized.

A tenth aspect of the present invention (corresponding to claim 10) is:
The reflective liquid crystal display device according to any one of the fifth to ninth aspects, wherein the retardation of the second birefringent film is 20 nm or less.

As described above, when the retardation of the second birefringent film is 20 nm or less, a change in retardation due to a change in viewing angle can be reduced, and coloring of display colors due to the provision of a scattering function in a wide viewing angle range can be corrected. Can be.

According to an eleventh aspect of the present invention (corresponding to claim 11),
A liquid crystal cell including a first substrate, a second substrate, and liquid crystal sealed between the first substrate and the second substrate; and the liquid crystal sealed into the first substrate. A polarizing film disposed on the opposite side to the side, between the first substrate and the polarizing film, and / or one or more scattering films disposed outside the polarizing film, At least one birefringence having retardation, which is arranged between the first substrate and the polarizing film and can suppress variation in different colors depending on an emission angle of light generated by the scattering film. A reflection type liquid crystal display device comprising: a film; and a light reflection unit disposed between the second substrate and the liquid crystal.

With this configuration, the scattering of the chromaticity of the display color due to the scattering function can be suppressed by the scattering film itself. At the same time, a reflective liquid crystal that diffuses incident light from angles other than the viewing direction and condenses it in the viewing direction increases reflectance, provides an achromatic white display, and achieves higher contrast. A display device can be provided.

According to a twelfth aspect of the present invention (corresponding to claim 12),
In the reflective liquid crystal display device according to the eleventh aspect of the present invention, a second liquid crystal display device, which is disposed on one of the side opposite to the side where the liquid crystal is sealed with respect to the first substrate and is different from the scattering film, is provided. A reflection type liquid crystal display device comprising a scattering film.

According to a thirteenth aspect of the present invention (corresponding to claim 13),
A twelfth reflective liquid crystal display device according to the present invention, wherein the birefringent film and the second scattering film are integrated.

With this configuration, the function can be separated into a scattering film having a scattering characteristic and a birefringent film having a chromaticity adjusting function, and the characteristics of the scattering film and the birefringent film can be easily separated from the viewpoint of material selection. Can be optimized.

The fourteenth invention (corresponding to claim 14) provides:
The reflective liquid crystal display device according to any one of the eleventh to thirteenth aspects, wherein the material of the birefringent film is an acetate-based cellulose.

According to a fifteenth aspect of the present invention (corresponding to claim 15),
A fourteenth aspect of the present invention, in the reflective liquid crystal display device, wherein the acetate-based cellulose is triacetate cellulose.

As described above, when the material of the birefringent film is an acetate-based cellulose, and particularly when it is a triacetate cellulose, the change in optical properties is very small under various use environments, and the properties are stable. In addition, since the acetate-based cellulose is colorless and transparent, an optimized optical configuration can be achieved, and an achromatic black-and-white display can be realized.

According to a sixteenth aspect of the present invention (corresponding to claim 16),
The reflective liquid crystal display device according to any one of the eleventh to fifteenth aspects, wherein the birefringent film has a retardation of 20 nm or less.

As described above, when the retardation of the birefringent film is 20 nm or less, a change in retardation due to a change in viewing angle can be reduced, and coloring of a display color due to the provision of a scattering function can be corrected over a wide viewing angle range.

The scattering film is preferably a forward scattering film. Here, the forward scattering film refers to a scattering film that has forward scattering characteristics but hardly any back scattering characteristics. In the case where there is back scattering, the reflectance of black display becomes high in the reflection type liquid crystal display device, high contrast cannot be obtained, and an image with high visibility cannot be obtained. Therefore, it is preferable to suppress back scattering. . In the case where the absorption by the scattering film is strong, the incident light passes through the scattering film twice in the reflection type liquid crystal display device, so that the reflectance of the outgoing light is low, and a dark white display is obtained. From these two points, it is desirable for the scattering film to have little absorption and backscattering of transmitted light, and to transmit almost all incident light. In particular, those having a total light transmittance of 85% or more are preferable.

[0035]

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) FIG. 1 is a sectional view of a reflection type liquid crystal display device according to a first embodiment. In FIG. 1, reference numeral 10 denotes a first forward scattering film 1
0a and a forward scattering film layer comprising a second forward scattering film 10b, 11 is a polarizing film (polarizer), 12
Denotes a birefringent film, 13 denotes a liquid crystal cell, 14 denotes an upper transparent substrate, 15 denotes a color filter, 16 denotes a transparent electrode, 17 denotes a liquid crystal layer, 18 denotes a mirror reflector (metal reflective electrode), and 19 denotes a lower substrate.

Next, FIG. 2 shows a conceptual diagram for defining the angle of the light incident on the forward scattering film layer 10. 10 is a forward scattering film layer, 21 is a direction of incident light on the forward scattering film layer 10, 22 is a normal direction of the forward scattering film layer 10, 23
Is an in-plane reference line. Also, as shown
Is the angle between the incident light direction 21 and the film normal direction 22, and the angle Φ is the angle between the in-film reference line 23 and the projection component 24 of the incident light direction 21 onto the film surface.

Now, a glass substrate is used as the upper transparent substrate 14 and the lower substrate 19 in FIG.
A stripe of green and blue was formed by photolithography, and a pixel electrode was formed thereon using indium tin oxide (ITO) as a transparent electrode 16. Further, on the lower substrate 19, a metal reflective electrode was formed as the specular reflector 18 by depositing silver on the lower substrate 19. After forming an alignment film on the transparent electrode 16 and the metal reflection electrode 18, an alignment process was performed by rubbing.

Then, a thermosetting sealing resin mixed with glass fiber is printed on a peripheral portion on the upper transparent substrate 14, and resin beads having a diameter of 4.5 μm are sprayed on the lower substrate 19. 14 and the lower substrate 19 were bonded together, and the sealing resin was cured at 150 ° C. afterwards,
An ester nematic liquid crystal having Δn = 0.14 was vacuum-injected, sealed with an ultraviolet curable resin, and then cured with ultraviolet light.

On the upper transparent substrate 14 of the liquid crystal cell 13 thus formed, the first forward scattering film 10a has a haze ratio of 60% with respect to the incident light direction 21 from the range of 0 ° ≦ θ ≦ 50 °. As described above, a forward scattering film (trade name "Lumisti") manufactured by Sumitomo Chemical Co., Ltd., in which the haze ratio for incident light from other regions is 10% or less, is set in a range where the haze ratio is 60%. Lamination was performed so that the main scattering direction was Φ = 90 °. Here, the main scattering direction refers to the center direction of a region where the haze ratio is 60% or more. The haze ratio is a value defined by (scattered light transmittance) / (total light transmittance) × 100 [%].

Further, the first forward scattering film 10a
A second forward scattering film 10b having a retardation was bonded onto the above so that the slow axis of the second forward scattering film 10b was orthogonal to the rubbing direction of the upper transparent substrate 14. Second forward scattering film 1 used here
0b is an anisotropic film having scattering properties with a haze ratio of only 20% in the stretching direction only, in which scattering is imparted by the surface shape formed by stretching the film. The slow axis direction is the stretching direction, and the retardation value is 20 nm.

Further, the retardation value is 490 nm.
Is bonded so that the slow axis of the birefringent film 12 is orthogonal to the rubbing direction of the upper transparent substrate 14, and the polarizing film 11 is further placed thereon so that the absorption axis has the rubbing direction of the upper transparent substrate 14. And a 45-degree angle. The birefringent film 12
Can suppress variations in different colors depending on the emission angles of light generated by the liquid crystal cell 13 and the polarizing film 11.

Note that the retardation value is a value indicating the phase delay of transmitted light of a substance having a refractive index anisotropy in terms of distance. Here, assuming that the extraordinary light refractive index is ne, the ordinary light refractive index is no, and the thickness of the substance having the refractive index anisotropy in the direction of transmitting light is d, the retardation value is the difference Δn between the refractive index and the thickness. It is expressed by the product Δnd of d and is shown below (Equation 1)
Let it be represented by

[0044]

Δnd = (ne−no) × d With the above configuration, a normally black mode reflective color liquid crystal display device which provides black display when no voltage is applied was obtained. According to such a reflective liquid crystal display device, since the second forward scattering film 10b has retardation, the second forward scattering film 10b has a display color due to the scattering characteristics of the second forward scattering film 10b itself. Variations in chromaticity can be corrected. In addition, the second forward scattering film 10b includes the first forward scattering film 10a.
It is also possible to correct the variation in chromaticity of the display color due to the scattering characteristics of. The first forward scattering film 10a is provided to further enhance the scattering characteristics.

By adopting such a reflection type liquid crystal display device, specifically, the contrast is 7.5 in frontal characteristics, the reflectance is 15.8% in terms of Y value in white display, and the saturation is 2. A good characteristic of 0 was obtained.

As a comparison regarding the correction of chromaticity, a configuration using a second forward scattering film 10b having a haze ratio to incident light of 20% and a retardation of 0 nm, that is, a configuration having no retardation was used. In this case, an achromatic white display such as a saturation of 9.7 was not obtained.

In the first embodiment, the upper transparent substrate 14 as the first substrate, the lower substrate 19 as the second substrate, and the liquid crystal cell as the liquid crystal cell according to the first or second aspect of the present invention. 13. Polarizing film 1 as polarizing film
1. The second forward scattering film 10 as the scattering film
b, The birefringent film 12 was used as the birefringent film, and the specular reflector 18 was used as the light reflecting means. Further, a first forward scattering film 10a was used as the second scattering film of the present invention according to claim 3.

In the first embodiment described above, the forward scattering film layer 10 is
a and the second forward scattering film 10b, the forward scattering film layer 10 may be constituted only by the second forward scattering film 10b, or May be constituted by the first forward scattering film 10a and the second forward scattering film 10b. When the forward scattering film layer 10 is formed from a plurality of first forward scattering films 10a and second forward scattering films 10b, scattering characteristics can be optimized, and incident light from angles other than the main observation direction of the observer can be reduced. Since the light can be condensed in the main observation direction by diffusing, the reflectance is increased, an achromatic white display can be performed, and a higher contrast can be realized.

In the above-described first embodiment, the second forward scattering film 10b is disposed between the birefringent film 12 and the first forward scattering film 10a. The location of the forward scattering film 10b depends on the birefringent film 12 and the first forward scattering film 1 described above.
0a. Second forward scattering film 10b
May be arranged between the polarizing film 11 and the birefringent film 12. In short, the second forward scattering film 1
Ob may be disposed anywhere between the upper transparent substrate 14 and the polarizing film 11. Alternatively, the second forward scattering film 10b may be arranged outside the polarizing film 11.

Further, in the above-described first embodiment, the first forward scattering film 10a is arranged between the upper transparent substrate 14 and the first forward scattering film 10b. The location of the forward scattering film 10a is the same as that of the upper transparent substrate 14 and the first forward scattering film 10b described above.
Not limited to The first forward scattering film 10a includes:
It may be arranged at any position as long as it is on the polarizing film 11 side with respect to the upper transparent substrate 14. Or, they do not have to be arranged.

Further, in the reflection type liquid crystal display device of the first embodiment, one birefringent film 12 is formed between the polarizing film 11 and the second forward scattering film 10b. The location of the birefringent film 12 is
There is no limitation between the polarizing film 11 and the second forward scattering film 10b. The arrangement place of the birefringent film 12 may be any place as long as it is between the upper transparent substrate 14 and the polarizing film 11. The number of the birefringent films 12 to be arranged is not limited to one, but may be plural. Alternatively, they need not be arranged.

(Second Embodiment) The structure and manufacturing method of the reflection type liquid crystal display device of the second embodiment are basically the same as those of the first embodiment, and are shown in FIG. It has the same cross-sectional structure as the folded structure. However, in this embodiment,
The first forward scattering film 10a is not used.

That is, unlike the above-described first embodiment, the second forward scattering film 10b having retardation is placed on the upper transparent substrate 14, and the slow axis of the second forward scattering film 10b is The transparent substrates 14 were bonded so as to be parallel to the rubbing direction. The forward scattering film 10b used here is composed of a scattering layer 31 and a base material 32 as shown in FIG. 3, and the scattering characteristics of the scattering layer 31 are isotropic, so that the light is incident regardless of the incident angle. The haze ratio for light is 50%. Triacetate cellulose was used as the material of the base material 32, and the retardation was 10 nm.

Then, similarly to the first embodiment, the birefringent film 12 and the polarizing film 11 were sequentially bonded thereon.

With the above configuration, a normally black mode reflection type color liquid crystal display device which provides black display when no voltage is applied was obtained. In addition, the forward scattering film layer 10 of the present configuration includes the forward scattering film 10 having retardation.
b.

According to such a reflection type liquid crystal display device,
Since the base material 32 of the scattering film 10b has retardation, the base material 32 can correct variation in chromaticity of a display color due to the scattering characteristics of the scattering layer 31 of the scattering film 10b. At the same time, by diffusing incident light from an angle direction other than the observer's main observation direction, the light can be collected in the main observation direction, so that the reflectance increases and an achromatic white display can be performed. And a higher contrast can be realized.

By adopting such a reflection type liquid crystal display element, specifically, the front characteristic is excellent such as a contrast of 6.0, a reflectance of 10.2% in terms of Y value of white display, and a saturation of 1.7. Characteristics were obtained. In addition, it has been confirmed that good results are obtained with respect to the chromaticity change of the display color depending on the viewing angle.

In the above-described second embodiment, the upper transparent substrate 1 is used as the first substrate according to the present invention.
4. Lower substrate 19 as a second substrate, liquid crystal cell 13 as a liquid crystal cell, polarizing film 11 as a polarizing film, scattering layer 31 of second forward scattering film 10b as a scattering film, birefringence as a first birefringent film. Film 1
2. The base material 32 of the second forward scattering film 10b as the second birefringent film, and the specular reflector 18 as the light reflecting means
Was used.

In the above-described second embodiment, the second forward scattering film 10b is disposed between the birefringent film 12 and the upper transparent substrate 14. The location of 10b is not limited between the above-described birefringent film 12 and upper transparent substrate 14. The second forward scattering film 10b may be disposed between the polarizing film 11 and the birefringent film 12. In short, the second forward scattering film 10b is the upper transparent substrate 1
What is necessary is just to arrange | position in any one between 4 and the polarizing film 11. FIG. Alternatively, the second forward scattering film 10b
It may be arranged outside the polarizing film 11.

In the above-described second embodiment, the second forward scattering film 10b comprises the scattering layer 31 and the base material 32.
Although the scattering layer 31 and the base material 32 are not necessarily integrated, they may be independent. Further, the number of the scattering layer 31 and / or the substrate 32 is not limited to one, and may be plural. Alternatively, a plurality of integrated second forward scattering films 10b including the scattering layer 31 and the base material 32 may be used.

In the second embodiment, one birefringent film 12 is formed between the polarizing film 11 and the second forward scattering film 10b. The arrangement place is not limited between the polarizing film 11 and the second forward scattering film 10b.
The arrangement place of the birefringent film 12 may be any place as long as it is between the upper transparent substrate 14 and the polarizing film 11. The number of the birefringent films 12 to be arranged is not limited to one, but may be plural.
Alternatively, they need not be arranged. The configuration of the reflection type liquid crystal display device when it is not arranged corresponds to the configuration of the reflection type liquid crystal display device of claim 11, and the base material 32 of the second forward scattering film 10 b corresponds to the birefringent film of claim 11. I do.

Further, in the above-described second embodiment, the first forward scattering film 10a is not used, but the first forward scattering film 10a may be used in order to enhance the scattering characteristics. In that case, the first forward scattering film 10a
Corresponds to the second scattering film of the present invention according to claim 6 or 12. In addition, the first forward scattering film 10a includes:
The upper transparent substrate 14 may be disposed on any side as long as it is on the opposite side to the side on which the liquid crystal cell 13 is disposed.

In the above-described second embodiment, the material of the base material 32 of the second forward scattering film 10b is triacetate cellulose.
Other acetate-based celluloses may be used. As described above, when the substrate 32 of the second forward scattering film 10b is made of acetate cellulose, the acetate-based cellulose is colorless and transparent, so that an optimized optical configuration can be achieved, and an achromatic black-and-white display can be realized. can do.

In the first and second embodiments described above, the retardation value of the second forward scattering film 10b or the base material 32 of the second forward scattering film 10b is assumed to be 20 or 10 nm. However, the second forward scattering film 10b corrects the chromaticity variation of the display color due to the scattering characteristics of the first forward scattering film 10a and the second forward scattering film 10b, or only the second forward scattering film 10b. Is possible, the retardation value of the second forward scattering film 10b or the base material 32 of the second forward scattering film 10b is 20 or 10
It is not limited to nm.

In the first and second embodiments described above, the retardation value of the birefringent film 12 is 4
Although it is assumed to be 90 nm, it is not limited to 490 nm.

In the first and second embodiments described above, the liquid crystal cell 13 is not limited to this liquid crystal mode, but may be a reflection type liquid crystal display element employing active driving by a thin film transistor (TFT) or the like. Substantially the same effect can be obtained regardless of the driving method.

In the first and second embodiments described above, silver is used as the specular reflection plate 18. However, the present invention is not limited to this. For example, a metal reflection electrode containing aluminum as a component may be used. Similar effects can be obtained.

Further, in the first and second embodiments described above, the forward scattering film 10b having a retardation having a haze ratio of 20% or 50% is used, but is not limited thereto. Haze rate of 4
A 0% forward scattering film may be used. Although one or two forward scattering films are used here, the present invention is not limited to this, and a similar effect can be obtained with a configuration of three or more sheets.

In the first and second embodiments described above, the slow axis of the forward scattering film 10b having the retardation is set to be orthogonal or parallel to the rubbing direction of the upper transparent substrate 14. The effect described above is not necessarily limited to this, and similar effects can be obtained by providing the optical configuration at an optimized angle.

[0070]

As apparent from the above description, the present invention can provide a reflection type liquid crystal display device in which the chromaticity variation of the display color due to the scattering characteristics of the forward scattering film is suppressed.

Further, the present invention provides a reflection type liquid crystal display device which compensates for the decrease in the scattering characteristic when correcting the chromaticity variation of the display color depending on the scattering characteristic of the forward scattering film. it can.

Accordingly, it is possible to diffuse incident light from an angle direction other than the main observation direction of the observer and to condense the light in the observation direction, to provide a high reflectance, achromatic white display, and to further enhance the contrast. Can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of a reflective liquid crystal display device according to a first embodiment of the present invention.

FIG. 2 is a perspective view of a scattering film for describing a definition of an angle of incident light on a first forward scattering film layer which is a component of the reflective liquid crystal display device according to the first embodiment of the present invention. is there.

FIG. 3 is a cross-sectional view illustrating a configuration of a scattering film having retardation of a reflective liquid crystal display device according to a second embodiment of the present invention.

FIG. 4 is a cross-sectional view illustrating a configuration example of a conventional reflective liquid crystal display device.

[Explanation of symbols]

 Reference Signs List 10 forward scattering film layer 10a first forward scattering film 10b second forward scattering film 11 polarizing film 12 birefringent film 13 liquid crystal cell 14 upper transparent substrate 15 color filter 16 transparent electrode 17 liquid crystal layer 18 specular reflector (metal reflective electrode) ) 19 Lower substrate 21 Incident light direction 22 Film normal direction 23 In-plane reference line 24 Projection component 31 Scattering layer 32 Substrate

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hisanori Yamaguchi 1006 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. Terms (reference) 2H091 FA02Y FA08X FA11X FA14Y FA31X FA31Z FB02 FD24 GA02 GA03 KA02 LA17

Claims (16)

[Claims] A first substrate, a second substrate, and the first substrate;
A liquid crystal cell composed of liquid crystal sealed between the substrate and the second substrate, a polarizing film disposed on the side opposite to the side where the liquid crystal is sealed with respect to the first substrate, One or more scattering films disposed between the first substrate and the polarizing film and / or outside the polarizing film; and between the first substrate and the polarizing film One or a plurality of birefringent films having retardation, which can be arranged in the liquid crystal cell and can suppress variations in different colors depending on an emission angle of light generated by the polarizing film; and the second substrate Light scattering means disposed between the liquid crystal and the liquid crystal, wherein the scattering film can suppress a variation in color that varies depending on an emission angle of light generated by the scattering film itself. Reflection type liquid crystal display device, characterized in that those having Tadeshon. 2. A first substrate, a second substrate, and the first substrate.
A liquid crystal cell composed of liquid crystal sealed between the substrate and the second substrate, a polarizing film disposed on the side opposite to the side where the liquid crystal is sealed with respect to the first substrate, One or more scattering films disposed between the first substrate and the polarizing film and / or outside the polarizing film; and disposed between the second substrate and the liquid crystal. A reflection type liquid crystal display device, comprising: a light reflection unit, wherein the scattering film has a retardation capable of suppressing a variation in different colors depending on an emission angle of light generated by the scattering film itself. . 3. The liquid crystal display according to claim 1, further comprising a second scattering film disposed on a side opposite to the side where the liquid crystal is sealed with respect to the first substrate, the second scattering film being different from the scattering film. 3. The reflective liquid crystal display device according to 1 or 2. 4. The retardation of the scattering film is 2
4. The reflection type liquid crystal display device according to claim 1, wherein the thickness is equal to or less than 0 nm. 5. A first substrate, a second substrate, and said first substrate.
A liquid crystal cell composed of liquid crystal sealed between the substrate and the second substrate, a polarizing film disposed on the side opposite to the side where the liquid crystal is sealed with respect to the first substrate, One or more scattering films disposed between the first substrate and the polarizing film and / or outside the polarizing film; and between the first substrate and the polarizing film One or more first birefringent films having retardation, wherein the first and second birefringent films have retardation that can suppress variations in different colors depending on emission angles of light generated by the liquid crystal cell and the polarizing film; Has a retardation that can be arranged between the substrate and the polarizing film and can suppress variations in different colors depending on the emission angle of light generated by the scattering film. A reflection type liquid crystal display device comprising: at least one or more second birefringent films; and light reflecting means disposed between the second substrate and the liquid crystal. 6. A liquid crystal display device further comprising a second scattering film which is disposed on one of the side opposite to the side where the liquid crystal is sealed with respect to the first substrate and which is different from the scattering film. The reflective liquid crystal display device according to claim 5. 7. The reflection type liquid crystal display device according to claim 6, wherein said second birefringent film and said second scattering film are integrated. 8. The reflection type liquid crystal display device according to claim 5, wherein a material of said second birefringent film is acetate-based cellulose. 9. The reflection type liquid crystal display device according to claim 8, wherein said acetate-based cellulose is triacetate cellulose. 10. The method according to claim 5, wherein the retardation of the second birefringent film is 20 nm or less.
10. The reflective liquid crystal display device according to any one of items 1 to 9. 11. A liquid crystal cell comprising a first substrate, a second substrate, and a liquid crystal sealed between the first substrate and the second substrate; And a polarizing film disposed on the side opposite to the side on which the liquid crystal is sealed, and one or more sheets disposed between the first substrate and the polarizing film and / or disposed outside the polarizing film. A scattering film, at least one having retardation that is disposed between the first substrate and the polarizing film and that can suppress a variation in color different depending on an emission angle of light generated by the scattering film. A reflective liquid crystal display device, comprising: at least one birefringent film; and light reflecting means disposed between the second substrate and the liquid crystal. 12. The liquid crystal display device according to claim 1, further comprising a second scattering film disposed on one of the side opposite to the side on which the liquid crystal is sealed with respect to the first substrate and different from the scattering film. The reflective liquid crystal display device according to claim 11. 13. The reflective liquid crystal display device according to claim 12, wherein said birefringent film and said second scattering film are integrated. 14. The reflective liquid crystal display device according to claim 11, wherein the material of the birefringent film is an acetate-based cellulose. 15. The cellulose acetate according to claim 14, wherein the acetate cellulose is triacetate cellulose.
The reflective liquid crystal display device as described in the above. 16. The reflective liquid crystal display device according to claim 11, wherein the retardation of the birefringent film is 20 nm or less.