JPH09146083A - Liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the contrast over the entire part of images and to obtain a bright image. SOLUTION: This liquid crystal display device has a liquid crystal cell 7 which is formed by enclosing liquid crystal between a pair of transparent substrates and in which pixels corresponding to three colors, red, green and blue are periodically arranged and a hologram 6 which emits parallel light incident at a prescribed incident angle in directions varying for every wavelength and makes the light incident on the pixels corresponding to the respective colors. The liquid crystal molecules are twist-oriented at 90 deg. twist angle by the orientation treatment applied to the opposed surfaces of the electrode substrate of the liquid crystal cell 7, thereby, the photolysis direction 6a of the hologram 6 and the orientation treatment direction 7a of the liquid crystal cell 7 crass at angle of 45 deg.. Then, the photolysis direction 6a of the hologram 6 and the direction of the best visual field angle characteristic of the liquid crystal cell 7 are aligned. The contrast is thereby improved even with the light having some angle and, therefore, the contrast over the entire part of the displayed images is improved and a bright image can be obtd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device that displays a color image.

[0002]

2. Description of the Related Art Conventionally, some liquid crystal display devices display a color image by irradiating the back surface of a liquid crystal display element with light from a light source. This liquid crystal display device uses red (R), green (G), and blue (B) color filters corresponding to each pixel of the liquid crystal display element, and is colored when light from a light source passes through the color filters. As a result, a color image is displayed. However, in such a liquid crystal display device, when the light from the light source passes through the color filter, the light of the complementary color component is absorbed by the color filter,
There is an inconvenience that the utilization efficiency of the light from the light source is poor and the color display becomes dark. For this reason, recently, a hologram is arranged between the light source and the liquid crystal display element, and this hologram disperses parallel light from the light source into specific wavelength components of R, G, and B, and at the same time, By collecting the light of each wavelength component from the light source, the light of each wavelength component is made incident on each color pixel of the liquid crystal display element by condensing on the pixel of the corresponding color,
Methods for improving the light utilization efficiency are being studied.

[0003]

However, in such a liquid crystal display device, when the direction of photolysis of the hologram and the direction of the best viewing angle characteristic of the liquid crystal display element are deviated,
Of the light emitted from the hologram, the contrast of the light that is angled to some extent is lowered, so that the contrast of the entire display image is deteriorated, and there is a problem that a clear image cannot be obtained. In general, the viewing angle characteristic of a liquid crystal display element when the orientation processing direction of the liquid crystal display element is horizontal (0 ° direction) or vertical (90 ° direction) is 4 with respect to the horizontal direction.
Since the hologram is inclined by 5 ° and the photolysis direction of the hologram is horizontal, the photolysis direction of the hologram and the direction of the best viewing angle characteristic of the liquid crystal display element are deviated, and the above problem occurs. . When such a liquid crystal display device is used in a liquid crystal projector, the viewing angle characteristics of the liquid crystal display element are inclined by 45 ° with respect to the horizontal direction (the photolytic direction of the hologram), and therefore the viewing angle characteristics are When only one side becomes extremely bad and the light that has passed through the liquid crystal display element is enlarged and projected on the screen by the projection lens as an image, the projection angle of the projection lens must be adjusted to the one with poor viewing angle characteristics. The overall contrast deteriorates,
In addition, the light with a certain angle must be cut by the projection lens, and the entire image becomes dark. An object of the present invention is to improve the contrast of the entire image and to obtain a bright image by matching the photolytic direction of the hologram with the direction of the best viewing angle characteristic of the liquid crystal display element. Is.

[0004]

According to the present invention, a liquid crystal display device in which liquid crystal is sealed between a pair of transparent electrode substrates, and pixels corresponding to three colors of red, green and blue are periodically arranged, What is claimed is: 1.A liquid crystal display device comprising: a hologram which emits parallel light incident at a predetermined incident angle in different directions for each wavelength and makes it enter a pixel corresponding to each color of a liquid crystal display element. By matching the direction of the best viewing angle characteristic of the display element, the contrast is improved even in light with a certain angle, and therefore the contrast of the entire display image is improved and a bright image can be obtained.
In this case, as described in claim 2, in the liquid crystal display element, the liquid crystal molecules are twisted and aligned at a twist angle of 90 ° by the alignment treatment performed on the facing surfaces of the pair of electrode substrates, and the hologram photolysis direction and the liquid crystal display are displayed. If the orientation processing direction of the incident side electrode substrate of the element intersects at an angle of 45 °, the photolysis direction of the hologram and the direction of the best viewing angle characteristic of the liquid crystal display element can be matched.

According to a third aspect of the present invention, a polarizing plate that transmits a specific linearly polarized light component of the parallel light on the incident side of the hologram is arranged perpendicularly to the parallel light, and the hologram is transparent. If the anti-reflection film is provided on the entrance surface of this transparent plate, the reflection of the light of the specific linearly polarized light component and the light of the linearly polarized light component orthogonal to the light incident on the transparent plate The difference in the ratio can be reduced by the antireflection film, whereby the generation of the elliptically polarized light component can be suppressed and only the light of the specific linearly polarized light component can be made incident on the liquid crystal display element, which also improves the contrast. it can. Further, as described in claim 4, when a retardation plate is arranged between the polarizing plate and the hologram arranged on the entrance side of the hologram, or between the hologram and the liquid crystal display element, parallel light is transmitted through the hologram to the liquid crystal. When entering the display element, the retardation plate can correct only the light of a specific linearly polarized component to enter the liquid crystal display element, which also improves the contrast.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION

[First Embodiment] A first embodiment of the liquid crystal display device of the present invention will be described below with reference to FIGS. FIG. 1 is a schematic configuration diagram of a liquid crystal display device. In this figure, reference numeral 1 denotes a light source unit, in which a light source 3 is arranged at a focal position of a reflector 2 formed of a paraboloid, and the light generated from this light source 3 is reflected by the reflector 2 as light parallel to an optical axis 4. It has become. In front of (reflecting side) of the light source unit 1, an incident side polarization plate 5 for selecting and transmitting light of a specific linearly polarized light component (light of either P polarized light component or S polarized light component) is arranged on the optical axis 4. It is arranged vertically. A hologram 6 is arranged on the exit side of the entrance-side polarization plate 5 at a predetermined angle (40 °) with respect to the optical axis 4. A liquid crystal cell (liquid crystal display element) 7 is arranged in parallel with the hologram 6 on the exit side of the hologram 6. Further, on the output side of the liquid crystal cell 7, an output side polarization plate 8 for selecting and transmitting light of a specific linear polarization component (light of either P polarization component or S polarization component) is arranged in parallel with the liquid crystal cell 7. Has been placed

The liquid crystal cell 7 is one in which liquid crystal is sealed between a pair of transparent electrode substrates, and liquid crystal molecules have a twist angle of 90 ° by an alignment treatment such as a rubbing treatment performed on the opposing surfaces of the pair of electrode substrates. Is twisted and oriented, and a large number of pixels are arranged in a dot matrix between a pair of electrode substrates, and a black matrix BM is formed corresponding to each pixel. In this case, the liquid crystal cell 7 has three pixels corresponding to three colors of R, G, and B as one pixel.
It has a structure in which a set of unit pixels is arranged periodically. The hologram 6 diffracts any wavelength with one diffraction grating, and diffracts at different diffraction angles depending on the wavelength. The hologram 6 passes through the incident side polarizing plate 5 and has a predetermined incident angle (40 °). As shown in FIG. 3, the incident light is made incident on the pixels of the liquid crystal cell 7 corresponding to each color. That is, as shown in FIG. 4, this hologram 6 is a unit hologram 9 (right in FIG. 4) corresponding to a unit pixel having a set of three pixels corresponding to three colors of R, G, and B of the liquid crystal cell 7. (Corresponding to the region indicated by the upward slanted lines) is periodically arrayed.

2A to 2D are plan views schematically showing the positional relationship of the optical axes of the optical elements with respect to the alignment treatment direction of the liquid crystal cell 7. The alignment treatment direction 7a applied to the electrode substrate on the incident side of the liquid crystal cell is shown in FIG.
As shown in, the liquid crystal molecules are inclined by 45 ° with respect to the reference line S along the left-right direction of the display surface, and the liquid crystal molecules near the incident side electrode substrate are arranged along the alignment processing direction 7a. The orientation processing direction 7b applied to the outgoing side electrode substrate is set to intersect with the incoming side orientation processing direction 7a at 90 °, and the outgoing side electrode substrate is aligned along this orientation processing direction 7b. Liquid crystal molecules in the vicinity are aligned. As a result, the number of liquid crystal molecules becomes 9
Oriented with a 0 ° twist. As shown in FIG. 2A, the transmission axis 5a of the incident side polarization plate 5 is set in a direction orthogonal to the incident side alignment treatment direction 7a of the liquid crystal cell 7. The photolytic direction 6a of the hologram 6 is as shown in FIG.
As shown in FIG. 6, the direction is set to be parallel to the reference line S, that is, to intersect with the alignment processing direction 7a on the incident side at an angle of 45 °. Further, as shown in FIG. 2D, the transmission axis 8a of the exit side polarizing plate 8 is parallel to the incident side alignment treatment direction 7a of the liquid crystal cell 7, that is, the direction orthogonal to the exit side alignment treatment direction 7b. Is set to.

In such a liquid crystal display device, the light from the light source 3 is reflected by the reflector 2 as light parallel to the optical axis 4, and this parallel light is vertically incident on the incident side polarization plate 5, and the incident side polarization is performed. Only the light of the specific linear polarization component is selected and transmitted by the plate 5, and the transmitted light of the specific linear polarization component is incident on the hologram 6 at an incident angle of 40 °. The light incident on the hologram 6 is, as shown in FIG.
Are diffracted at different diffraction angles for each of the R, G, and B wavelength components and enter the pixels of the liquid crystal cell 7 corresponding to each color. That is, the light of the R wavelength component is incident on the pixel corresponding to the R color of the liquid crystal cell 7, and the light of the G wavelength component is the G of the liquid crystal cell 7.
The light of the B wavelength component is incident on the pixel corresponding to the color, and the light of the B wavelength component is incident on the pixel of the liquid crystal cell 7 corresponding to the B color. The light incident on each pixel of the liquid crystal cell 7 is rotated and emitted when passing through the liquid crystal cell 7, and the emitted light of each wavelength component is incident on the emission side polarization plate 8, and this emission side polarization plate Only light of a specific linear polarization component is selected by 8 and transmitted. At this time, if the liquid crystal cell 7 is driven, a color image corresponding to the driving is displayed.

As described above, in this liquid crystal display device, the photo-decomposition direction 6a of the hologram 6 and the alignment treatment directions 7a and 7b of the liquid crystal cell 7 intersect each other at an angle of 45 °. The direction 6a and the direction of the best viewing angle characteristic of the liquid crystal cell 7 can be made to coincide with each other, so that the contrast is improved even in light with a certain angle, and the contrast of the entire display image can be improved, resulting in a bright image. A display image can be obtained. Particularly, in this liquid crystal display device, the incident side alignment treatment direction 7a of the liquid crystal cell 7 is formed.
On the other hand, since the transmission axis 5a of the incident side polarization plate 5 is made orthogonal to each other and the transmission axis 8a of the emission side polarization plate 8 is made perpendicular to the emission side alignment treatment direction 7b of the liquid crystal cell 7, the contrast is very good. By the way, in this liquid crystal display device, the viewing angle characteristics as shown in FIG. 5 are obtained. That is, this figure shows isocontrast curves when observed from a direction tilted in each direction (clockwise direction of the clock) from the normal direction of the liquid crystal cell 7 (clockwise axis direction of the clock). Here, the scale on each azimuth is 4 ° with respect to the normal direction of the liquid crystal cell 7 in order from the center,
8 °, 12 °, 16 °, 20 °, and 24 ° are tilted directions. The two-dot chain line has a contrast of 500, the dotted line has a contrast of 400, and the solid line has a contrast of 300, 1.
The dotted line represents a contrast of 200. As shown in this figure, in this liquid crystal display device, the viewing angle characteristic is best in the left-right direction (the direction of 3:00 to 9:00 in the clock), and this direction coincides with the photolytic direction of the hologram 6. Therefore, a contrast of 200 or more can be obtained even with a certain angle of light (light of 0 ° to ± 20 °).

Although the liquid crystal display device has been described in the first embodiment, the invention is not limited to this. For example, a projection lens is arranged on the exit side of the exit side polarization plate 8 and the liquid crystal cell 7 is transmitted by this projection lens. The light thus generated may be enlarged and projected as an image on the screen. In this case, the photolytic direction 6a of the hologram 6 and the alignment treatment direction 7a of the liquid crystal cell 7,
Since 7b and 45b intersect each other at an angle of 45 °, the light decomposition direction 6a of the hologram 6 and the direction of the best viewing angle characteristic of the liquid crystal cell 7 coincide with each other, and the light with a certain angle (0 °
Since the contrast is good even with light of up to ± 20 °), when the display image is projected by the projection lens, the capture angle of the projection lens can be set to about ± 20 °, and the contrast of the entire projected image can be improved. Since the light cut by the projection lens is small, a bright projection image can be obtained.

[Second Embodiment] Next, referring to FIG.
A second embodiment in which the present invention is applied to a liquid crystal projector will be described. The same parts as those in the first embodiment shown in FIGS. 1 to 5 are denoted by the same reference numerals, and description thereof will be omitted. In this liquid crystal projector, as shown in FIG. 6, a hologram 6 is provided on the exit surface of a transparent plate 10 such as glass, and an antireflection film 11 made of an optical multilayer film or the like is provided on the entrance surface of the transparent plate 10 by vapor deposition or the like. Similar to the first embodiment, this transparent plate 10 is provided on the exit side of the entrance side polarization plate 5 with respect to the optical axis 4.
The projection lens 12 is arranged at an angle of 0 °, and the projection lens 12 is arranged on the exit side of the exit side polarization plate 8, and the projection lens 12 has a structure in which light transmitted through the liquid crystal cell 7 is enlarged and projected as an image on a screen (not shown). Has become. Also in this liquid crystal projector, as in the first embodiment, the alignment processing direction 7a on the incident side of the liquid crystal cell 7 is 45 ° with respect to the horizontal reference line S.
It is inclined, and the orientation processing direction 7b on the exit side is set to be orthogonal to the orientation processing direction 7a on the incidence side. Further, the transmission axis 5a of the incident side polarization plate 5 is set to be a direction orthogonal to the incident side alignment treatment direction 7a, and the photolytic direction 6a of the hologram 6 is parallel to the reference line S, that is, the incident side alignment treatment. It is set at a direction inclined by 45 ° with respect to the direction 7a, and the transmission axis 8a of the exit side polarization plate 8 is set parallel to the alignment processing direction 7a on the entrance side, that is, a direction orthogonal to the alignment processing direction 7b on the exit side. There is.

In such a liquid crystal projector, as in the case of the first embodiment, the parallel light from the light source unit 1 receives the incident side polarization plate 5.
When incident on, the incident side polarization plate 5 selects and transmits the light of the specific linear polarization component, and the transmitted light of the specific linear polarization component passes through the transparent plate 10 at a predetermined angle (40 °). It enters the hologram 6. At this time, since the transmission axis 5a of the incident-side polarization plate 5 is inclined by 45 ° with respect to the reference line S, light having a specific linear polarization component (for example, P-polarization component light) on the incident surface of the transparent plate 10, It is conceivable that a difference in reflectance will occur between the light of the linearly polarized light component (for example, the light of the S-polarized light component) orthogonal to this, but since the antireflection film 11 is provided on the incident surface of the transparent plate 10, This antireflection film 11 reduces the difference in reflectance between light of a specific linearly polarized light component (light of P polarized light component) and light of a linearly polarized light component (light of S polarized light component) orthogonal thereto. Therefore, the generation of the elliptically polarized light component in the hologram 6 can be suppressed, and the decrease in the degree of polarization can be prevented, which makes it possible to obtain a brighter display image with higher contrast than in the first embodiment.

Also, in this liquid crystal projector, as in the first embodiment, the photolytic direction 6a of the hologram 6 and the alignment treatment directions 7a and 7b of the liquid crystal cell 7 intersect at an angle of 45 °, so that the hologram Since the photolytic direction 6a of 6 and the direction of the best viewing angle characteristic of the liquid crystal cell 7 coincide with each other and the contrast is good even for light with a certain angle (light of 0 ° to ± 20 °), it is displayed by the projection lens 12. When projecting an image, the capture angle of the projection lens 12 can be set to about ± 20 °, the contrast of the entire projection image can be improved, and since the light cut by the projection lens 12 is small, a bright projection image can be obtained. Obtainable.

In the second embodiment, the transparent plate 10
Although the hologram 6 is provided on the exit surface of the above, the invention is not limited to this. For example, the hologram 6 may be provided on the entrance surface of the transparent plate 10 and the antireflection film 11 may be attached to the entrance surface of the hologram 6. With such a structure, a cost-effective and low-priced product can be obtained.

[Third Embodiment] Next, a third embodiment in which the present invention is applied to a liquid crystal projector will be described with reference to FIGS. Also in this case, the same parts as those in the first embodiment shown in FIGS. 1 to 5 are designated by the same reference numerals, and the description thereof will be omitted. In this liquid crystal projector, as shown in FIG. 7, a retardation plate 15 is arranged between an incident side polarizing plate 5 and a hologram 6 in parallel with the incident side polarizing plate 5 and projected on an emitting side of an emitting side polarizing plate 8. A lens 12 is arranged, and the projection lens 12 has a structure in which light transmitted through the liquid crystal cell 7 is enlarged and projected as an image on a screen (not shown). In this case, the phase difference plate 15 is a quarter-wave plate, and when light enters the hologram 6, the phase of the incident light is preliminarily shifted in consideration of the change in the polarization state caused by the hologram 6, thereby The polarization state at 6 is corrected so as to be a linear polarization state, and is incident on the liquid crystal cell 7.

In this liquid crystal projector, FIG.
As shown in FIG. 8E, the positional relationship of the optical axes of each optical element is set. That is, the alignment processing direction 7a on the incident side of the liquid crystal cell 7 is inclined by 45 ° with respect to the horizontal reference line S as in the first embodiment, as shown in FIG. The processing direction 7b is set to be a direction orthogonal to the alignment processing direction 7a on the incident side. As shown in FIG. 8A, the transmission axis 5a of the incident side polarization plate 5 is set in a direction orthogonal to the incident side alignment treatment direction 7a. As shown in FIG. 8B, the optical axis 15a of the retardation plate 15 is parallel to the transmission axis 5a of the incident-side polarization plate 5, that is, inclined by 45 ° with respect to the reference line S. As shown in FIG. 8C, the photolytic direction 6a of the hologram 6 is 45 with respect to the direction parallel to the reference line S, that is, the orientation processing direction 7a on the incident side.
° It is set in a tilted direction. Further, as shown in FIG. 8E, the transmission axis 8a of the exit side polarization plate 8 is set parallel to the incident side alignment treatment direction 7a, that is, a direction orthogonal to the exit side alignment treatment direction 7b. There is.

In such a liquid crystal projector, when the parallel light from the light source unit 1 is incident on the incident side polarization plate 5, the incidence side polarization plate 5 selects the light of a specific linear polarization component shown in FIG. 9A. Then, the transmitted light of the specific linearly polarized light component is incident on the phase difference plate 15, and the phase difference plate 15 causes the light of FIG.
As shown in (b), the phase is shifted to an elliptically polarized state, and the light in this elliptically polarized state enters the hologram 6.
At this time, the transmission axis 5a of the incident side polarization plate 5 is set to the reference line S.
Since the light beam is inclined by 45 ° with respect to the light incident surface of the hologram 6, light of a specific linear polarization component (for example, light of P polarization component)
It is conceivable that there will be a difference in reflectance between the light having a linearly polarized light component (for example, light having an S-polarized light component) orthogonal to this, and elliptically polarized light due to this difference in reflectance. By shifting the phases and setting the elliptically polarized state in the reverse rotation, the elliptically polarized state in the reverse rotation cancels out the elliptically polarized state generated on the entrance surface of the hologram 6. Therefore, it is possible to suppress the generation of the elliptically polarized light component in the hologram 6 and prevent the deterioration of the polarization degree.

The light diffracted by the hologram 6 and emitted at different angles for each wavelength is incident on the liquid crystal cell 7 as specific linearly polarized light as shown in FIG. 9 (c). The contrast is higher than that of the first embodiment, and a bright display image can be obtained. Also, when the display image is projected on the liquid crystal cell 7 by the projection lens 12, the photolytic direction 6 of the hologram 6 is the same as in the second embodiment.
Since a and the direction of the best viewing angle characteristic of the liquid crystal cell 7 match, the acceptance angle of the projection lens 12 can be set to about ± 20 °, the contrast of the entire projected image can be improved, and the projection Since the light cut by the lens 12 is small, a bright projected image can be obtained.

[Fourth Embodiment] Next, referring to FIGS. 10 to 12, a fourth embodiment of the present invention is applied to a liquid crystal projector.
An embodiment will be described. Also in this case, FIGS.
The same parts as those of the third embodiment shown in are attached with the same notations and an explanation thereof will be omitted. In this liquid crystal projector, as shown in FIG. 10, a retardation plate 16 which is a half-wave plate is arranged in parallel with the hologram 6 between the hologram 6 and the liquid crystal cell 7, and the hologram is reflected by the retardation plate 16. The light of the specific linearly polarized light component emitted from 6 is made incident on the liquid crystal cell 7 by shifting the phase, and the light transmitted through the liquid crystal cell 7 by the projection lens 12 arranged on the emission side of the emission side polarization plate 8 is imaged. The structure is such that it is enlarged and projected on the screen.

In this liquid crystal projector, FIG.
As shown in FIG. 11E, the positional relationship of the optical axes of the optical elements is set. That is, as shown in FIG. 11D, the alignment treatment direction 7a on the incident side of the liquid crystal cell 7 is
Similar to the first embodiment, 45 ° with respect to the horizontal reference line S
It is inclined, and the orientation processing direction 7b on the exit side is set to be orthogonal to the orientation processing direction 7a on the incidence side. As shown in FIG. 11A, the transmission axis 5a of the incident side polarization plate 5 is set in a direction orthogonal to the reference line S, that is, in a direction inclined by 45 ° with respect to the incident side alignment treatment direction 7a. . As shown in FIG. 11B, the photolytic direction 6a of the hologram 6 is set in a direction parallel to the reference line S, that is, a direction inclined by 45 ° with respect to the alignment processing direction 7a on the incident side. The optical axis 16a of the retardation plate 16 is 22.5 relative to the transmission axis 5a of the incident side polarization plate 5, as shown in FIG.
67. with respect to the direction intersecting at an angle of .degree.
It is set in a direction inclined by 5 °. Further, as shown in FIG. 11 (e), the transmission axis 8a of the exit-side polarization plate 8 is set to be parallel to the alignment processing direction 7a on the entrance side, that is, the direction orthogonal to the alignment processing direction 7b on the exit side. There is.

In such a liquid crystal projector, when the parallel light from the light source unit 1 enters the incident side polarization plate 5, the incident side polarization plate 5 emits light (S) having a specific linear polarization component shown in FIG. The light of the polarization component) is selected and transmitted, and the transmitted light of the S polarization component is incident on the hologram 6. At this time, since the transmission axis 5a of the incident-side polarization plate 5 is orthogonal to the reference line S, only the light of the S-polarized component is incident on the incident surface of the hologram 6, so that the incident surface of the hologram 6 is incident. Therefore, there is no difference in reflectance. Therefore, as shown in FIG. 12B, the light that has entered the hologram 6 exits at a different angle for each wavelength in the S-polarized state and enters the retardation film 16. The light incident on the phase difference plate 16 is
As shown in FIG.
The phase is shifted to become linearly polarized light that is orthogonal to the incident side alignment processing direction 7a of the liquid crystal cell 7, and the light of this linearly polarized component is incident on the liquid crystal cell 7, so the contrast is higher than in the first embodiment. A bright display image can be obtained. Also, when the light transmitted through the liquid crystal cell 7 is projected as an image by the projection lens 12, the photolytic direction 6a of the hologram 6 and the direction of the best viewing angle characteristic of the liquid crystal cell 7 are the same as in the second embodiment. Since the projection lens 12 and the projection lens 12 have the same angle, the acceptance angle of the projection lens 12 can be set to about ± 20 °, and the contrast of the entire projected image can be improved.
Since the light cut by 2 is small, a bright projection image can be obtained.

In the above second to fourth embodiments, the case where the projection lens 12 is arranged on the exit side of the exit side polarization plate 8 and applied to the liquid crystal projector for enlarging and projecting the display image on the screen has been described. The present invention is not limited to this, and by removing the projection lens 12, it can be used as a liquid crystal display device. Moreover, in the said 1st-4th embodiment,
Light of a linearly polarized light component in a direction orthogonal to the incident side alignment treatment direction 7a of the liquid crystal cell 7 is made incident, and the transmission axis 8 of the emission side polarization plate 8 is made to the emission side alignment treatment direction 7b of the liquid crystal cell 7.
Although the case where a is orthogonalized is described, the invention is not limited to this.
For example, light of a linearly polarized component parallel to the incident side alignment treatment direction 7a of the liquid crystal cell 7 may be made incident, and the transmission axis of the emission side polarization plate 8 may be made incident to the emission side alignment treatment direction 7b of the liquid crystal cell 7. 8a may be arranged in parallel. Further, in the above-described first to fourth embodiments, the case where the TN type liquid crystal cell 7 in which the liquid crystal molecules are twisted by 90 ° is used is described, but the present invention is not limited to this, and may be applied to the STN type liquid crystal cell. You can Also in this case, the direction of the viewing angle characteristics of the liquid crystal cell and the photolytic direction of the hologram may be matched.

[0024]

As described above, according to the first aspect of the invention, the direction of the best viewing angle characteristic of the liquid crystal display device in which the pixels corresponding to the three colors of red, green and blue are periodically arranged. When,
By collimating parallel light incident at a predetermined incident angle in different directions for each wavelength and incident on the pixels corresponding to each color of the liquid crystal display element, the light decomposition direction of the hologram is made to match, so that light with a certain angle However, the contrast is improved, so that the contrast of the entire display image can be improved and a bright image can be obtained. Further, according to the invention described in claim 3, since the antireflection film is provided on the entrance surface of the transparent plate having the hologram on the exit surface, the light of a specific linearly polarized component in the light entering the transparent plate. And the difference in reflectance between the light of the linearly polarized light component and the light orthogonal to this can be reduced by the antireflection film, thereby suppressing the generation of the elliptically polarized light component and allowing only the light of the specific linearly polarized light component to enter the liquid crystal display element. It is also possible to improve the contrast. Further, according to the invention described in claim 4, since the retardation plate is arranged between the polarizing plate and the hologram arranged on the entrance side of the hologram, or between the hologram and the liquid crystal display element, the parallel light is reflected by the hologram. When the light enters the liquid crystal display element through the phase difference plate, it can be corrected by the retardation plate so that only the light of the specific linearly polarized light component enters the liquid crystal display element, which also improves the contrast.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a first embodiment of a liquid crystal display device of the present invention.

FIG. 2 is a plan view schematically showing the positional relationship of the optical axes of the optical elements shown in FIG.

3 is a diagram showing a state in which light diffracted by the hologram of FIG. 1 is incident on a pixel corresponding to each color of a liquid crystal cell.

FIG. 4 is a diagram showing a correspondence relationship between the hologram of FIG. 1 and a liquid crystal cell.

FIG. 5 is a diagram showing viewing angle characteristics of a liquid crystal cell.

FIG. 6 is a schematic configuration diagram showing a second embodiment in which the present invention is applied to a liquid crystal projector.

FIG. 7 is a schematic configuration diagram showing a third embodiment in which the invention is applied to a liquid crystal projector.

8 is a plan view schematically showing the positional relationship of the optical axes of the optical elements shown in FIG.

9 is a plan view schematically showing the polarization state of light between the incident side polarization plate and the liquid crystal cell of FIG.

FIG. 10 is a fourth example in which the present invention is applied to a liquid crystal projector.
1 is a schematic configuration diagram showing an embodiment.

11 is a plan view schematically showing the positional relationship of the optical axes of the optical elements shown in FIG.

12 is a plan view schematically showing the polarization state of light between the incident side polarizing plate and the liquid crystal cell of FIG.

[Explanation of symbols]

 1 Light Source Section 2 Reflector 3 Light Source 4 Optical Axis 5 Incident Side Polarizing Plate 5a Transmission Axis 6 Hologram 6a Photolytic Direction 7 Liquid Crystal Cell 7a Incident Side Alignment Treatment Direction 7b Emission Side Alignment Treatment Direction 8 Emission Side Polarizer 8a Transmission Axis 10 Transparent Plate 11 Antireflection Film 12 Projection Lens 15 and 16 Phase Difference Plate

Claims (4)

[Claims] 1. A liquid crystal display device, in which liquid crystal is sealed between a pair of transparent electrode substrates, and pixels corresponding to three colors of red, green and blue are periodically arranged, and a parallel liquid crystal which is incident at a predetermined incident angle. A liquid crystal display device comprising: a hologram that emits light in different directions for each wavelength and makes it enter a pixel corresponding to each color of the liquid crystal display element, wherein a photolytic direction of the hologram and a best visual field of the liquid crystal display element. A liquid crystal display device characterized in that the directions of corner characteristics are matched. 2. The liquid crystal display device has a liquid crystal molecule of 90 ° by an alignment treatment performed on the facing surfaces of the pair of electrode substrates.
2. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is twisted and aligned at a twist angle of, and the photolytic direction of the hologram intersects with the alignment treatment direction of the liquid crystal display element at an angle of 45 °. 3. A polarizing plate that transmits a specific linearly polarized light component of the parallel light is disposed perpendicularly to the parallel light on the incident side of the hologram, and the hologram is provided on the exit surface of the transparent plate. 3. The liquid crystal display device according to claim 1, wherein an antireflection film is provided on the incident surface of the transparent plate. 4. A polarizing plate, which transmits a specific linearly polarized light component of the parallel light, is disposed perpendicular to the parallel light on the incident side of the hologram, and between the polarizing plate and the hologram. The liquid crystal display device according to claim 1, further comprising a retardation plate disposed between the hologram and the liquid crystal display element.