JPH04120586A - Image display device - Google Patents

Abstract

PURPOSE:To utilize a polarized light component effectively and improve the brightness of a display by transmitting plural polarized light beams through a common liquid crystal display element along different optical paths, modulating them and generating pieces of information luminous flux, and converging them on the same optical axis and obtaining a composite image. CONSTITUTION:Polarization beam splitters 4a and 4b are used to split light from a light source 1 into two polarized light components which have mutually orthogonal planes of polarization and the same liquid crystal display element 20 is irradiated with the polarized light components in mutually different directions. Then the relation between the orienting direction of liquid crystal molecules and the direction of the polarization plane of the incident light is classified by an extraordinary light mode wherein the long-axis direction of the liquid crystal molecules and the plane of polarization of the input light are parallel and an ordinary light mode wherein the long-axis direction of the liquid crystal molecules and the plane of polarization of the input light cross each other at right angles. Further, an optical correcting means, e.g. prisms or linear Fresnel prisms 6a and 6b, etc., are arranged between the liquid crystal display element 20 and a projection lens 8. Consequently, the light of the light source can be utilized without any waste and the projection type image display device which has a bright screen is obtained.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a projection type color liquid crystal display device using a liquid crystal display element, and is particularly applicable to a high brightness projection type color television (TV) system. It is applied to information display systems.

<Prior Art> A conventionally known projection type color liquid crystal display device will be briefly described.

Projection TVs using liquid crystal display elements are being developed as an alternative to the conventional method of projecting images displayed on a cathode ray tube onto a screen, so-called projection TVs.
Commercial products have already appeared.

Since the liquid crystal display element itself does not emit light, it is necessary to provide a separate light source, but the principle technology has the characteristic that it can display a screen that is as bright as desired depending on the brightness of the light source. However, compared to CRT projection color TVs with the same screen size, they are much smaller and lighter, so further development is expected.

There are two types of liquid crystal display devices depending on the driving method: a simple matrix type and an active matrix type, and the present invention is applicable to both types. Projection type color image display systems using such liquid crystal display elements include a three-panel type that uses a total of three liquid crystal display elements, and a single-panel type that uses only one liquid crystal display element, depending on the three primary colors.

The former three-panel type uses three liquid crystal display elements, which display red, green,
A pair of optical systems that transmit all of the color light of each of the three primary colors of blue and a display element that controls the color light to form an image is provided independently, and images of each color are superimposed on the optical system to display full color. . A special example is one in which three individual light sources and all seven color letters are used as sources of red, green, and blue color light.
Disclosed in Japanese Patent No. 60-8291, the light from a single white light source is split into three primary color lights of red, green, and blue using a dichroic ink mirror, and each color light is displayed on a liquid crystal display element corresponding to the color. It is also possible to irradiate the rays with a ray of light, and an example of this is disclosed by Ganto Honro in Japanese Patent Application Laid-Open No. 169827/1983. As the white light source, a halogen lamp, a xenon lamp, a metal halide lamp, etc. are used. The emission spectrum may be a continuous spectrum or an emission line spectrum (V). With this configuration, the light and sound emitted from a common white light source can be effectively utilized, so if other conditions are the same, an image that is about 3 times brighter than the conventional single-panel configuration described below can be obtained, but compared to the single-panel type. Since the number of parts is large, it is disadvantageous in terms of cost and compactness of the device compared to the plate type.

Here, the dichroic ink mirror is a dichroic ink mirror formed with a dielectric multilayer thin film using a well-known thin film forming technique, or a dichroic ink mirror that selectively reflects or transmits only light in a wavelength range on a transparent substrate such as glass. A dichroic prism used in color TV imagers is used in which a similar dielectric multilayer thin film for wavelength selection is formed on the surface of a prism. In a single-panel configuration that only uses a mosaic of three primary color filters, similar to direct-view LCD TVs,
It projects a liquid crystal display element with a pattern using an optical system similar to a slide projector.
No. 230.383. This method has a simple optical system configuration and uses only one liquid crystal display element, so it is suitable for small projection systems. However, in this method, about two-thirds of the light irradiated onto the liquid crystal display element is absorbed or reflected by the color filter. For example, a red color filter is placed on a pixel that displays red, but this red color filter blocks green and blue light.)
be done. Therefore, only 1/3 of the light incident on the liquid crystal display element can be used, and the brightness of the screen is reduced to about 1/3 compared to the case of using the same light source sound with the 3-panel liquid crystal display element type described above. . In addition to this, for a single-panel liquid crystal display device, the liquid crystal display element is illuminated with all-white light, and minute gicchroic mirrors, microprism arrays, or diffraction gratings are arranged in correspondence with the weights of picture elements of the three primary colors. JP-A No. 61-21, No. 0828 discloses a configuration for full color display.
JP-A-62-293222, JP-A-62-29822
No. 8, JP-A-68-118125.

<Problems to be Solved by the Invention> A conventional projection type liquid crystal display device using a liquid crystal display element using a polarizing plate, particularly a twisted nematic (TN) type liquid crystal display element, Only one polarized component of the polarizing component was used, and the other polarized component was absorbed by the polarizing plate and did not contribute to display. An object of the present invention is to fully improve display brightness by fully utilizing the other polarization component, which was not utilized in conventional projection type liquid crystal display devices.

In addition, as a method that makes full use of the other polarized light component, which has not been used in the past, the light beam from one light source is separated into two polarized light components by a polarizing beam splitter, and each polarized light component illuminates a separate liquid crystal display element. However, a display system in which images are projected using independent lenses and combined on a screen, or a display system in which images are combined using a second polarizing beam splitter and then projected is disclosed in Japanese Utility Model Application Publication No. 1-1.0782.
However, these methods require two liquid crystal display elements, resulting in an increase in cost. In addition, in Japanese Utility Model Application No. 68-150922 and Japanese Patent Application Laid-open No. 63-188480, the polarization plane of one of two polarized light components separated by a polarizing beam splitter is rotated by a total of 908, and the polarization plane of the two components is changed. A method has been disclosed in which each luminous flux illuminates half of the display screen of the same liquid crystal display element, but in this method, the brightness becomes discontinuous at the boundary between the irradiation areas of the two luminous fluxes, resulting in display problems. There is a problem that the quality is easily damaged. Furthermore, in Japanese Patent Application Laid-Open No. 61-90584, one of the two polarization components separated by a polarization beam nullator is polarized 15. A method has been disclosed in which the planes of polarization of the two components are aligned by rotating f' by 90°N, and each light beam illuminates the display screen of the same liquid crystal display element from different angles.
In this method, the optical axes of the two light beams do not coincide, so the two light beams are far apart at the entrance pupil of the projection lens and become one. In order to effectively project both light beams onto the screen, There is a problem that a projection lens with a very large aperture must be completely circular.

<Means for Solving All Problems> In order to achieve all of the above objects, the present invention uses a polarizing beam splitter instead of a conventional polarizing plate, and splits the light from the light source into two beams having mutually orthogonal polarization planes. The light is separated into polarized light components, and each polarized light component is configured to irradiate the same liquid crystal display element from different directions. , the well-known twisted operation mode of liquid crystal display elements.
Nematic mode is preferred. This mode is determined by the relationship between the orientation direction of liquid crystal molecules and the direction of the polarization plane of the incident light.
It is classified into an extraordinary light mode in which the long axis direction of the liquid crystal molecules and the polarization plane of the incident light are parallel to each other, and a normal light mode in which the long axis direction of the liquid crystal molecules and the polarization plane of the incident light are orthogonal to each other. Conventional twisted nematic mode liquid crystal displays utilize only either the normal light mode or the extraordinary light mode, but the present invention uses both the normal light mode and the extraordinary light mode. It is configured as follows.

Next, by employing the above means, the optical axis (traveling direction) of each polarized light component is no longer perpendicular to the liquid crystal display element. It is placed between the liquid crystal display element and the projection lens.

In addition, in order to equalize the voltage-transmittance characteristics of the twisted nematic mode liquid crystal display element with respect to the incident angle of each polarized light component, the polarization plane of the incident light is rotated by 45 degrees before and after the liquid crystal display element as necessary. An optical element may also be added.

Further, a microlens array is disposed at least on the surface of the liquid crystal display element on the light source side, so that the light beams t@4 from two directions whose polarization planes are orthogonal to each other incident thereon are condensed at different positions with respect to the microlens. You can also. At this time, if the angle of incidence of each polarized light component with respect to the microlens array is selected to meet the conditions described below, each condensing sporatra can be made to enter the pixel apertures adjacent to each other. This condition is that a light beam passing through the center of one microlens passes through the center of an adjacent picture element aperture. This condition requires that the difference in the angle of incidence of two polarized lights be θ
, the focal length of the microlens in air, and the corresponding pixel spacing, it can be expressed as tanθ=p/fu.

<Function> The projection type liquid crystal display device of the present invention can obtain an image on the display screen using both the normal light mode and the extraordinary light mode. Compared to the device, the efficiency of using light from the light source is increased, and the brightness of the display screen can in principle be improved by about two to several times.

<Embodiment> FIG. 1 is a schematic diagram of an optical path of a projection type image display device which is an embodiment of the present invention. In the figure, 1 is a light source, 150W
, arc length AL-5ff, arc diameter Aφ = 2.28
A white light source is used, consisting of metal halide lamps arranged so that the arc is perpendicular to the plane of the paper. As other white light sources, halogen lamps and xenon lamps can be used. A spherical mirror 2 is arranged on the back side of the white light source 1,
A condenser lens 3 with an aperture of 80 mm and a focal length of fc-60 fi is arranged on the front surface. The center of the spherical mirror 2 is arranged so as to coincide with the center of the light emitting part of the white light source 10,
Furthermore, the center of the light emitting part of the white light source 1 is the condenser lens 3.
is placed so that it coincides with the focal point of the With this arrangement, the light emitted from the white light source 1 through the condenser lens 3 becomes a substantially parallel white light beam. The parallelism of the luminous flux at this time is approximately 2.2° in the arc length direction (direction parallel to the paper surface of Figure 1) and approximately 1° in the arc diameter direction (direction parallel to the paper surface of Figure 1). It is. Next, this parallel light beam is passed through a polarization beam nuplitter 4a into two polarized light beam P components having planes of polarization perpendicular to each other (in FIG. 1, the plane of polarization is parallel to the plane of the paper>-S component (in FIG. 1, the plane of polarization is parallel to the plane of the paper). Further, plane mirrors 5a and 5b are used so that each polarized light beam illuminates the same liquid crystal display element 20 at a predetermined angle.
The direction of travel is bent at . Here, the predetermined angle refers to a direction inclined at 30 degrees with respect to the normal line of the display screen and tilted toward the optimum viewing angle direction. Both components have a symmetrical relationship in the optimum viewing angle direction. Incidentally, the optical path lengths from the polarizing beam nuplitter 4a to the liquid crystal display 20 do not necessarily have to be equal for each polarized light component.

FIG. 2 shows a schematic cross-sectional view of the liquid crystal display element 20 and the microlens array 10 used in this embodiment. The liquid crystal display element 20 includes two glass substrates 21a.

A liquid crystal layer 22 is sealed between 21b and a well-known amorphous layer.
Rystened nematic mode (T
N)'s active micro-type liquid crystal display element is used. The pixel pitch is 100 μm both vertically and horizontally, the size of the pixel opening is 50 μm x 70 μm, and the number of pixels is 45 vertically.
It is set to a delta array of 0 x 600 horizontally. The pixel open rate is 35%. In the figure, the liquid crystal molecules C alignment film and the like are omitted for the sake of simplicity.

Next, the microlens array 10, which is an important element of this embodiment, will be explained. In the active matrix method described above, in order to supply an independent drive voltage to each picture element, each picture element is provided with all stages of elements such as thin film 1-run sisters or MIMs, and all picture elements are connected to each other in a line that supplies drive signals to them. and the picture element. Furthermore, if light incident on a region other than the picture element region leaks, the black level of the display screen will be raised and the contrast will be reduced. To prevent this, a light-shielding mask is usually provided in areas other than the picture elements, and is configured to absorb or reflect light that does not contribute to display. Therefore, when the display panel is illuminated with the same illuminance, a problem arises in that the lower the aperture ratio of the display panel, the darker the screen becomes. As a means to solve such problems,
Nos. 0-165621 to 165624 disclose a configuration in which a "microlens array" is provided on the light source side of a display panel, and illumination light is focused on each pixel area to improve the utilization rate of illumination light. ing. However, these publications do not mention the type of light source or the parallelism of illumination light.
There is also no mention of projecting images. However, looking at its configuration, it can be inferred that the effect of expanding the viewing angle can be expected. Furthermore, in Japanese Patent Application Laid-Open No. 60-262131, a pair of lens elements are provided for each picture element on both sides of the display panel, and the first lens focuses the illumination light incident on the display panel onto the picture element area. , after passing through the display area,
It has been disclosed that the light that diverges at an angle determined by the numerical aperture is converted into a nearly parallel beam of light by a second lens. If it is provided only on the light source side of the element, the almost parallel light flux incident on the microlens array is converged and passes through the pixel area of the ζ night crystal display element, and after being modulated according to the image signal, It spreads within a solid angle determined by the numerical aperture (NA) of the microlens, but
If the aperture of the projection lens is increased so as to receive all of these luminous fluxes, the light transmitted through the liquid crystal display panel will not be restricted thereby. In other words, the light that enters the liquid crystal display panel and travels through the pixel area is effectively used, so a brighter image can be obtained compared to a projection type image display device without microlenses.

The following methods can be used to form a microlens array used for this purpose.

(1) A method of obtaining a gradient index lens by selective ion diffusion. This method involves immersing a glass plate as a matrix in molten salt, exchanging ions such as different types of alkali ions between the glass plate and the molten salt through a mask provided on the glass plate, and creating a pattern corresponding to the mask pattern. How to make a glass plate with refractive index distribution (Electronics Lett
ers Vow.

17 No. 13 o452 (1981)).

When the entire microlens is formed using this method, the outer shape of the lens has no irregularities, so it can be attached to the liquid crystal display panel using Canada balsam or a photocurable resin without passing through the air, and the substrate Reflection loss at the surface can be reduced to an almost negligible level.

(2) A method of molding plastic or glass using a mechanical tool or a mold. In addition to directly processing the mold, it is also possible to use a mold formed by the following method (3) as a master mold and f) transferred by a method such as electroforming.

(3) When a certain type of photosensitive resin is exposed in a pattern,
A method of forming a convex lens by utilizing the phenomenon that unreacted polymers move from the non-exposed area to the exposed area and the exposed area bulges (Journal of Applied Physics Society of Optics, Micro-Optics Research Group Vol. 1.5 No. 2 pH8 (1987), Vol. 1.6 No. 2p87 (1988)).

(4) The thermoplastic resin is patterned into the planar shape of a lens using well-known photography techniques, and then heated to a temperature above its softening point to give it fluidity and cause edges to sag to obtain a convex lens. That method. in this case,
If the thermoplastic resin is photosensitive, it can be patterned by exposing itself to light (Japanese Patent Laid-Open No. 6
0-38989, JP-A-60-165623, JP-A-61-67003).

(5) Proximity n light (a method of exposing without fully contacting the photomask) is applied to the photosensitive resin, and the amount of photoreaction products is distributed according to the blurring of the edges of the pattern.
A method for obtaining a convex lens shape (Japanese Patent Application Laid-open No. 158602/1983).

(6) A method in which a photosensitive resin is irradiated with light having an intensity distribution to form a pattern with a refractive index distribution corresponding to the intensity of the light, thereby providing a full lens effect (Japanese Patent Application Laid-open No. 72927/1983).

A material whose refractive index changes upon irradiation with light is disclosed in JP-A-60-166946.

(7) Patterned light irradiation is applied to a photosensitive glass that has been made photosensitized by a silver salt, and the resulting silver crystal nuclei are grown by a total heat treatment, resulting in crystallization of the glass. A method of obtaining a convex lens using the volumetric shrinkage associated with (Applied Optics)
VoL 24 No.

16p2520 (1985)).

Furthermore, application of a combination of such a microlens array and a mosaic color filter to a liquid crystal display device is disclosed in Japanese Patent Application Laid-open No. 61-208080 and Japanese Patent Application Laid-Open No. 62-1989.
No. 94826, JP-A-62-203126, JP-A-6
It is disclosed in No. 2-267791, Japanese Unexamined Patent Publication No. 62-267723, etc.

However, there is no mention of application to a projection display device.

In this example, the microlens array 10 was formed by an ion exchange method. Its focal length is t = 1. I made it equal to N'II.

However, when the focal length of the microlens is measured in air, t/n = 1.1 tx71.58 = 0.72
It becomes B. Here, n represents the refractive index of the substrate of the liquid crystal display element. This was adhered to the light source side surface of the liquid crystal display element 20 with an optical adhesive so as to correspond to the arrangement of the picture elements.

When this microlens array 10 is irradiated with a parallel beam of light from a predetermined direction, the light is focused into spots at intervals of 100 μm corresponding to the arrangement of the microlenses where the optical axis of each microlens intersects with the liquid crystal layer. This focused spot is a reduced image of the light source created by the condenser lens and microlens [
Reduction ratio: fu (focal length of microlens)/fC (focal length of condenser lens)], and the size is 60 μm x 26.4 when calculated from the dimensions of the above-mentioned Noark.
Since it is μm, it fits within the pixel aperture.

Next, from the initial direction θ= tan' (mX f00
/720) When another parallel beam is irradiated from an inclined direction,
A condensing spot is formed m×100 μm horizontally from each initial condensing spot, and falls within the lightning pole of the picture element spaced m apart. However, m is an integer. On the actual flow side, m is ±3, and 22.6 degrees left and right from the optimum viewing angle direction described later.
A book was irradiated with a polarized light beam. Even if the light is focused by a microlens, the plane of polarization does not change, so the light beams of each polarized component propagate through the liquid crystal layer as normal light mode and extraordinary light mode, respectively, and the signal voltage applied to the liquid crystal layer The plane of polarization is rotated accordingly. In a twisted nematic mode liquid crystal display element, there is a slight difference in characteristics between the normal light mode and the extraordinary light mode, and there is also a viewing angle dependence depending on the alignment process of the liquid crystal molecules. In the present invention, the characteristics of the two modes do not necessarily have to match exactly;
The overall brightness-applied voltage characteristic obtained by combining the two modes is the average value of the two modes. However, if the characteristics of both modes differ in pressure end, the steepness of the combined characteristics will deteriorate, which is not preferable.

By the way, in a normal twisted nematic mode liquid crystal display element, each of the two substrates is subjected to alignment treatment such as well-known rubbing treatment in a direction tilted approximately 45 degrees left and right with respect to the vertical direction of the screen, and the optimum viewing angle direction is determined. is set so that it is in the 12 o'clock direction and Vi6 o'clock direction with respect to the screen.

In this case, since the viewing angle dependence of the characteristics becomes bilaterally symmetrical, the transmittance-voltage characteristics can be made almost the same by making the two polarized light beams completely incident from angles that are bilaterally symmetrical with respect to the optimum viewing angle direction. In this case, in both the normal light mode and the extraordinary light mode, the screen C is diagonally 4
Light with a polarization plane of 5° must be incident. However, in the arrangement shown in Figure 1, the polarized beef splinter-4a
The planes of polarization of the two polarized light components separated by are parallel and perpendicular to the plane of the paper, respectively, so in order to align the alignment direction of the liquid crystal molecules with these planes, the screen of the liquid crystal display element must be rotated a total of 45 degrees vertically. However, since the shape of the polarizing beam nuplitter is generally cubic and the cross section of the emitted light beam is square, the method of rotating the screen of the liquid crystal display element by 45 degrees vertically will produce a polarized beam nuplitter that is -circularly larger than the screen size of the liquid crystal display element. liter is required, which is disadvantageous in terms of cost. As an alternative to this, in this embodiment, an optical element for rotating the plane of polarization of the incident light by 45 degrees is added in front of and behind the liquid crystal display element (not shown), and the plane of polarization perpendicular and parallel to the plane of paper is rotated by 45 degrees with respect to the plane of paper. Tilt the liquid crystal molecules to match the orientation direction of the liquid crystal molecules described above. After passing through the liquid crystal display element, the plane of polarization is again rotated a total of 458 times to return the plane of polarization to perpendicular and parallel to the plane of the paper. As an optical element for rotating the plane of polarization of incident light by 45 degrees, a twisted nematic liquid crystal cell with a twist angle of 45 degrees is used. Since it is not necessary to apply a voltage to this 7-hole, it is only necessary to perform alignment treatment on the Galanus substrate and fill it with the bonded liquid crystal. If this 45° twist liquid crystal cell and liquid crystal display element are bonded together using an all-optical adhesive, reflection loss at the interface between the two can be reduced to an almost negligible level. As an optical element for rotating the plane of polarization of incident light by 45 degrees, it is also possible to use a stack of optically anisotropic films with their optical axes rotated little by little.

Since the respective light beams transmitted through the liquid crystal display element 20 travel in different directions, the liquid crystal display element 20 is different from the other.
, 5e, the beam is bent in its traveling direction, and is input to a polarizing beam nuplitter 4b to combine two polarized beams. The polarizing beam splinter 4b also serves as an analyzer for the light transmitted through the liquid crystal display element 20. FIG. 1 shows the plane of polarization when no voltage is applied to the liquid crystal display element.

Here, since the two polarized light components are combined and displayed on one screen by superimposing them, the optical path length from the liquid crystal display element 20 to the polarized beam nullifier 4b'1 must be equal for each polarized light component, and Including the reflection of one polarization component by the polarizing beam splitter 4b, the number of reflections must be the same or the difference in the number of reflections must be an even number. Furthermore, since the angle of incidence of each polarized light beam on the liquid crystal display element is different, the image formation planes of the projected images by the respective polarization light beams will intersect. In order to correct this and align the image formation surfaces, a prism or Near Fresnel prism (prism with serrated cross section) - ft static A Urako silkworm rod 2
Insert between 0φ≧Melon flat beam sp I+...J n -4b.

! Light is emitted from the light beam splinter 4b in two directions (NW and NB directions in FIG. 1), but the intensities thereof are complementary, and one (NW in FIG. 1) is emitted from the liquid crystal display element 2.
The mode is normally white, which is brightest when no voltage is applied to the liquid crystal display element 20 and becomes darker as the applied voltage increases, and the other mode (NB in FIG. 1) is when no voltage is applied to the liquid crystal display element 20. The mode becomes a normally black mode, which is sometimes dark and becomes brighter as the applied voltage is increased.

Either one of the lights emitted from the polarizing beam splitter 4b is further projected onto a screen 9 by a projection lens 8 to display an image. In order to shorten the back throw of the projection lens 8, a relay lens is placed between the liquid crystal display element 20 and the polarizing beam splitter 4b, and a field lens is placed near the polarizing beam splitter star 4b.
An image of the liquid crystal display element 20 may be formed there.

In a conventional liquid crystal display device equipped with a polarizing plate, the amount of incident light is about 1. /2 was cut off, but in the present invention, all of the incident light is used, so the luminous flux incident on the surface of the liquid crystal display element is increased to almost twice that of the conventional one, and the light focusing effect of the microlens is also improved. Since the effective aperture ratio has also been approximately doubled, the brightness of the display screen has been improved to approximately four times that of conventional models.

In the present invention, if the parallelism of illumination light is poor or if stray light, that is, light from a direction different from the expected direction, enters the liquid crystal display element, it may cause a decrease in display contrast, so this is necessary. Depending on the situation, the light from the light source may be focused on a spot using a condenser lens, and unnecessary light may be cut using a slit or pinhole.

Furthermore, if the polarization beam splitters 4a and 4b do not sufficiently separate the polarization components, a polarizing plate may be inserted after the polarization beam splitter 4a or before the polarization beam splitter 4b, if necessary. In this case, since most of the light incident on the polarizing plate is already polarized, the insertion loss is 20
It is about %.

Although the return angle of the polarizing beam splitter is generally 45 degrees, it does not necessarily have to be 45 degrees, and a polarizing prism using a birefringent crystal such as a Wolanneton prism may be used. FIG. 3 shows a second embodiment in which the number of reflections from a plane mirror is reduced by using such a polarizing beam splitter 4C. In this embodiment, in order to equalize the optical path lengths of the two polarized light beams, a linear Fresnel prism 6a is used only in the -10,000 optical path. Furthermore, since the tilt of the liquid crystal display element 20 with respect to the optical axis is not corrected, trapezoidal distortion of the projected image can be eliminated by aligning the optical axis of the projection lens 8 and the normal to the NuClean 9 with respect to the traveling direction of the illumination light. I can do it. Incidentally, FIG. 3 shows an optical path diagram when the normally black mode is used.

<Effects of the Invention> According to the present invention, it becomes possible to utilize the light from the light source without wasting it, and a projection type image display device with a very bright screen can be realized.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of an image display device for explaining one embodiment of the present invention. FIG. 2 is a schematic diagram showing the positional relationship between the pixel aperture and the microlens array of the image display device shown in FIG. 1. FIG. 3 is a schematic diagram of the image display device for explaining another embodiment of the present invention. . 1: Light source 2: Spherical mirror 3: Condenser lens
4a, 4b: polarizing beam splitter 5a, 5b, 5c
, 5d, 5e: Plane mirrors 6a, 6b: Linear Fresnel prism 8: Projection lens 9 Niscreen 10:
Microlens array 202 liquid crystal display element 21a,
21b Ni glass substrate 21C: Picture element opening 22:
Liquid crystal layer 4C: Polarizing beam splitter - 5f: Plane mirror 6C: Linear Fresnel prism

Claims (1)

[Claims] 1. After a plurality of polarized lights having planes of polarization in different directions are transmitted through a common liquid crystal display element along different optical paths and modulated to form a plurality of information light beams, the information light beams are An image display device comprising an optical system that focuses light onto the same optical axis to obtain a composite image on a display screen. 2. Claim 1, wherein the liquid crystal display element is provided with microlenses for condensing polarized light corresponding to the arrayed picture elements.
The image display device described in Section 1.