JPH1062782A - Manufacture of hologram element for projection type liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To embody the color sepn. adapted to the pixel arrangement of a liquid crystal display element and to obtain a shape having good light condensing efficiency by irradiating the element with object light at the time of forming interference fringes from the direction having the angle meeting the pixel arrangement. SOLUTION: At the time of forming the interference fringes corresponding to blue pixels 15c, optical system are installed on the same plane (x-y plane) on both of a reference light side and an object light side and the object light (Bo) is cast within the same plane (x-y plane) as the plane of the reference light (Br). At the time of forming the interference fringes corresponding to green pixels 15b, the optical systems on the object light side among the optical systems are arranged on the plane (z plane) orthogonal with the x-y plane and the object light (Go) is cast from the angle θdirection with respect to the reference light (Gr) to be cast from the direction within the x-y plane. Further, at the time of forming the interference fringes corresponding to the red pixels, the optical systems on both of the reference light side and the object light side are installed on the same plane (x-y plane) and the object light (Ro) is cast within the same plane as the plane of the reference light (Rr).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a hologram element for a projection type liquid crystal display device using a hologram element as a color separation means.

[0002]

2. Description of the Related Art As a liquid crystal display device, there is a projection type display device (liquid crystal projector) for projecting and displaying on a screen together with a direct-view type display device. In this projection type liquid crystal display device, light emitted from a single white light source is separated into three primary colors for color display by color separation means, and each color light is separated into a pixel (liquid crystal) of a liquid crystal display element corresponding to the color. (Cell), where it is modulated according to the reproduced image and then projected on the screen to display a color image. Such a projection type liquid crystal display device is a single-panel type using one liquid crystal display element with color separation means of three colors of red (Red = R), green (Green = G), and blue (Blue = B). And
It can be broadly classified into a three-panel system using three monochrome liquid crystal panels for each of the red, green and blue optical paths.

[0003] A single-panel type projection display device emits light emitted from a single white light source by one color separation means into red, green, and red light.
Dichroic mirrors are used to separate the light into three primary colors of blue, and a dichroic mirror is conventionally used as the color separation means. As a color liquid crystal display device using this dichroic mirror as a color separating means, there is one disclosed in, for example, Japanese Patent Application Laid-Open No. Hei 4-60538. In this color liquid crystal display device, white light emitted from a white light source is separated by three dichroic mirrors arranged at different angles for each of the three primary colors, and the separated light of each color is passed through a microlens. Light is condensed on each pixel of the liquid crystal display element.

[0004]

However, a color liquid crystal display device using such a dichroic mirror and a microlens has the following problems. That is, if the three primary colors of red, green, and blue are separated by a dichroic mirror, the three primary colors can be separated only in the same plane. Therefore, the pixel arrangement of the liquid crystal display element is linear such as horizontal or vertical. Can only take a simple array. When a liquid crystal display element having such a linear pixel arrangement is used, the configuration of a set (optical system) is restricted. In addition, there is a problem that the shape of the microlens needs to be linear in accordance with the pixel arrangement, and lens processing is difficult. Further, in the case of using a so-called delta (triangle) liquid crystal display element in which pixels of three primary colors of red, green, and blue are arranged in a triangular shape, for example, one set of pixels (red , Green, and blue) to correspond to one microlens, it is necessary to increase the size of one microlens more than necessary, and there is a problem that a useless portion that does not contribute to light collection occurs.

The present invention has been made in view of such a problem, and an object of the present invention is to realize color separation suitable for a pixel arrangement of a liquid crystal display element without restricting the configuration of an optical system. It is an object of the present invention to provide a method of manufacturing a hologram element for a projection-type liquid crystal display device, in which a microlens as a light condensing means can be formed into a shape having good light condensing efficiency corresponding to a pixel array, and can facilitate lens processing. is there.

[0006]

According to a method of manufacturing a hologram element according to the present invention, a white light source emitting white light is arranged along a first direction and a second direction orthogonal to each other on the same plane. A set of multiple types of pixels,
A liquid crystal display element configured by regularly arranging this set,
A plurality of interference fringes corresponding to a plurality of types of pixels are formed, and white light emitted from a white light source is separated into a plurality of primary color lights according to a pixel arrangement, and these separated primary color lights are respectively guided to a liquid crystal display element. A method of manufacturing a hologram element for a projection-type liquid crystal display device, comprising:
When forming interference fringes on the substrate for the hologram element, the reference light for the substrate corresponds to the incident light of white light from the white light source in a plane including the direction corresponding to the first direction of the pixel array in the liquid crystal display element. And the object light when forming interference fringes corresponding to the type of pixels arranged in the first direction in the set of pixels of the liquid crystal display element is the same as the reference light. In the direction of the reference light in an angle corresponding to the pixel arrangement in the plane of the liquid crystal display device, and the interference corresponding to the other type of pixels arranged in the second direction in the set of pixels of the liquid crystal display element. The object light for forming the stripes is irradiated to the reference light from a direction having an angle corresponding to the pixel arrangement in the second direction of the pixel arrangement of the liquid crystal display element.

In particular, according to the method of manufacturing a hologram element according to the present invention, a first primary color pixel in which a set of pixels constituting a liquid crystal display element are arranged adjacent to each other along a first direction of a pixel array is provided. And a second primary color pixel, and a third primary color pixel arranged along the second direction so as to form a triangular shape together with the first primary color pixel and the second primary color pixel. The liquid crystal display element has a delta arrangement,
This is effective when the configuration has one microlens as a light condensing means corresponding to one set of pixels.

In such a method of manufacturing a hologram element according to the present invention, a plurality of pixels arranged along a first direction and a second direction in a pixel array of a liquid crystal display element with respect to a hologram substrate, respectively. , An interference fringe is formed. Therefore, in the hologram element manufactured by this method, white light emitted from the white light source is separated into a plurality of primary color lights according to the pixel arrangement (for example, delta shape) of the liquid crystal display element, and these separated primary color lights are separated. Each is guided to each pixel of the liquid crystal display element.

[0009]

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

FIG. 1 shows a schematic configuration of a projection type liquid crystal display device 10 according to an embodiment of the present invention as viewed from above. Projection type liquid crystal display device 1 according to the present embodiment
0 is a white light source 11 that emits white light;
1, a reflection mirror (reflector) made of, for example, a spherical mirror, a condenser lens 13 disposed in front of a white light source 11, and a hologram element 14 disposed in front of the condenser lens 13 as color separation means. , Hologram element 14
Liquid Crystal Display (LCD; Liquid Cry)
stal display) 15, a projection lens 16 arranged on the front of the liquid crystal display element 15, and a screen 17 for image formation.
It consists of.

The white light source 11 only needs to be capable of emitting white light including the three primary colors of red, green, and blue. For example, a metal halide lamp, a halogen lamp, a xenon lamp, or the like is used. The condenser lens 13 condenses the white light emitted from the white light source 11 and converts the white light into parallel light.
It leads to 4.

The hologram element 14 is not of the type in which the diffraction efficiency does not depend on the wavelength (that is, the type in which only a specific wavelength is diffracted like a Lippmann hologram and the other wavelengths are not diffracted). Hologram element). As such a hologram element, there are, for example, a relief method, a phase method, an amplitude method, and the like. Hologram element 14
For example, a photopolymer (Omnidex 352 manufactured by DuPont) is used as an element material for forming the light-emitting device, and interference fringes corresponding to the wavelengths of the three primary colors are formed by a method described below. Hologram element 14 according to the present embodiment
As shown in FIGS. 2 and 3, the pixel arrangement of the liquid crystal display element 15 for each of the three primary colors of red, green and blue of the white light condensed by the condensing lens 13 as shown in FIG. And is transmitted to the liquid crystal display element 15 side at an angle adapted to the above.

FIG. 2 shows a light transmission state when the hologram element 14 is viewed from above. In the drawing, the horizontal direction of the paper surface is the y direction of the xyz coordinate system, the vertical direction is the x direction, and the direction perpendicular to the paper surface is the z direction. On the other hand, FIG. 3 shows a light transmission state when the same hologram element 14 is viewed from the side. In this figure, the horizontal direction is the y direction, the vertical direction is the z direction, and the direction perpendicular to the paper surface is the x direction. In the present embodiment, when the hologram element 14 is viewed from the side (FIG. 3), the red and blue primary color lights are on the same plane (in this embodiment, the plane (x perpendicular to the pixel plane of the hologram 14). -Y-plane)). When the hologram element 14 is viewed from above (FIG. 2), the light passes through the liquid crystal display element 15 in different directions at an angle suitable for the pixel arrangement. On the other hand, when the hologram element 14 is viewed from the side (FIG. 3), the green primary color light is along a plane (z plane) orthogonal to the transmission plane (xy plane) of the red and blue primary color lights. When the hologram element 14 is viewed from above (FIG. 2), the hologram element 14 is transmitted in a direction different from the primary colors of red and blue at an angle suitable for the pixel arrangement of the liquid crystal display element 15. It has become. Here, the transmission angle θ of the green primary color light
Is a delta liquid crystal display element 15 described later (FIG. 4).
It is determined according to the positional relationship of the green pixel 15b with respect to the red pixel 15a and the blue pixel 15c in the set of pixels 15a to 15c.

The liquid crystal display element 15 has a set of pixels (liquid crystal cell) 1 corresponding to three colors of red, green and blue as shown in FIG.
5a to 15c are arranged in, for example, a delta (triangle) shape, and this set is arranged regularly. In this figure, the horizontal direction of the paper is the x direction (first direction), and the vertical direction is the z direction.
The direction (second direction), the direction perpendicular to the paper surface, is the y direction. In the present embodiment, a red pixel 15a and a blue pixel 15c of a set of pixels 15a to 15c are juxtaposed in the x direction (first direction) in FIG.
5b is arranged along the z direction (second direction). Specifically, the liquid crystal display element 15 is, for example, as shown in FIGS.
And a microlens group 30 as a light collecting means attached to the front surface of the element body 20. FIG. 5 (a) corresponds to a state where the portion indicated by arrow a in FIG. 4 is viewed from the side, and FIG. 5 (b) corresponds to a state where the portion indicated by arrow b in FIG. 4 is viewed from above. I have. The element body 20 is 2
A liquid crystal layer 23 is sealed between a pair of glass substrates 21 and 22. Signal electrodes 24R, 24G, 24B and a scanning electrode (not shown) constituting a matrix electrode structure for driving the liquid crystal layer 23 are provided. It has a structure arranged on the inner surfaces of the glass substrates 21 and 22. The microlens group 30 includes a plurality of microlenses 30a, and one microlens 30a is arranged to face the three pixels 15a, 15b, and 15c (that is, the signal electrodes 24R, 24G, and 24B). Signal electrodes 24R, 24G, 2
4B and the scanning electrode are each formed of a transparent conductive film, and drive signals of red, green, and blue are input to the signal electrodes 24R, 24G, and 24B, respectively. The red light transmitted through the hologram element 14 is applied to the signal electrode 24R as shown in FIG.
0a. Green light transmitted through the hologram element 14 is incident on the signal electrode 24G via the microlens 30a as shown in FIG. Further, blue light transmitted through the hologram element 14 is incident on the signal electrode 24B via the microlens 30a as shown in FIG. That is, the signal electrodes 24R, 24G,
The intensity of the light of each color incident on each of the lights 24B is modulated according to the input state of the drive signal to the signal electrodes 24R, 24G, and 24B according to the reproduced image.
Note that, for simplicity, a polarizing plate, an alignment film, and the like, which are components of the liquid crystal display element, are omitted here.

The projection lens 16 combines the light modulated and transmitted by the liquid crystal display element 15 and magnifies and forms an image on a screen 17.

Next, a specific method of manufacturing the hologram element 14 will be described with reference to FIGS. 4, 6A to 6C, and 7A and 7B. Here, FIG.
(A) to (c) show the hologram substrate 14 for each manufacturing process.
7A shows a state when viewed from above, and FIGS. 7A to 7C show states when the hologram substrate 14a is viewed from the side in the same manufacturing process.

In the present embodiment, first, FIG.
As shown in (a), for example, a blue laser beam, that is, a reference beam (Br) is applied to the hologram substrate 14a having a film thickness of 10 μm, Angle θ suitable for the array of pixels 15c
₁ is irradiated with object light (Bo), and interference fringes are formed by these lights. When forming an interference fringe corresponding to the blue pixel 15c, an optical system (not shown) for fabrication is set on the same plane (xy plane) on both the reference light side and the object light side, As shown in the side view of FIG. 7A, the object light (Bo) is coplanar with the reference light (Br) (x
-Y plane). Subsequently, as shown in FIG. 6B, a laser beam for green, that is, a reference beam (Gr) is applied to the same hologram substrate 14a, and the liquid crystal display element 15 receives the reference beam (Gr). Green pixel 15b
Is irradiated with the object light (Go) at an angle θ ₂ suitable for the arrangement of the above, and an interference fringe is formed by these lights. When forming interference fringes corresponding to the green pixel 15b, the arrangement of the optical system on the object light side of the optical system (not shown) for fabrication is different from that of the red pixel 15a. By arranging the object light (Go) on the plane (z plane) orthogonal to the xy plane, the object light (Go) is located within the xy plane, as shown in the side view of FIG. 7B. The reference light (Gr) emitted from the direction is emitted from a direction forming a predetermined angle θ. Subsequently, as shown in FIG. 6 (c), the same laser beam for red, that is, the reference light (Rr) is applied to the same hologram substrate 14a, and the liquid crystal display element 15 responds to the reference light (Rr). object light (Ro) was irradiated at an angle theta ₃ adapted to the arrangement of red pixel 15a, forming interference fringes by these lights. When forming an interference fringe corresponding to the red pixel 15a, an optical system (not shown) for manufacturing is formed on the same plane on both the reference light side and the object light side as in the case of the blue pixel 15c. 7 (c), the object light (Ro) is placed on the same plane (xy plane) as the reference light (Rr), as shown in the side view of FIG. 7 (c).
Irradiate within. Thus, interference fringes corresponding to the pixels (blue, green, and red) in the delta arrangement are formed on the hologram substrate 14a.

The incident angle of the reference light (Gr, Rr, Br) with respect to the hologram substrate 14a is such that the white light emitted from the white light source 11 is the hologram substrate 14a.
The angle is set to be the same as the angle of incidence on a. The incident angles θ _{1 to} θ ₃ of the object light with respect to the reference lights (Gr, Rr, Br) (FIG. 6) take into account the focal length of the micro lens 30a (FIG. 5) in addition to the arrangement pitch of the pixels of each color. Need to decide.

In the projection type liquid crystal display device 10 using the hologram element 14 manufactured by such a method, the white light emitted from the white light source 11 and reflected by the reflecting mirror 12 is condensed by the condensing lens 13. After being converted into parallel light, the light enters the hologram element 14. The three primary colors of red, green and blue of the white light incident on the hologram element 14 are transmitted at a different angle for each color as shown in FIG. 2, and further transmitted to the liquid crystal display element 15 through the microlenses 30a. The light is incident on the pixels 15a to 15c corresponding to the respective color components. The light of the three primary colors that has entered the liquid crystal display element 15 is spatially modulated by the reproduced image of the liquid crystal display element 15 for each color, and then guided to the projection lens 16. The modulated light that has entered the projection lens 16 is combined here to form an image on the screen 17. Thus, a color image is displayed.

As described above, in the projection type liquid crystal display device 10 according to the present embodiment, when the hologram element 14 is viewed from the side (FIG. 3), the red and blue primary color lights are on the same plane (xy). (Green plane) in the directions different from each other, and the green primary color light has an angle θ with respect to the xy plane.
Because it is configured to transmit only in different directions,
Red, green, and blue primary color lights are appropriately incident on the pixels 15a to 15c of the delta arrangement of the liquid crystal display element 15, respectively. Therefore, color separation suitable for the pixel arrangement of the liquid crystal display element 15 can be performed without restricting the set (optical system) configuration, and a bright image display with good color reproducibility can be performed.

In addition, in the present embodiment, since the primary color light can be separated corresponding to the pixels 15a to 15c of the delta arrangement of the liquid crystal display element 15, the shape of the microlens 30a as the light condensing means is changed to the delta shape. Figure 4 according to the arrangement
Can be made hexagonal as shown in FIG. Therefore, the work of processing the microlens is facilitated, and unnecessary portions that do not contribute to light collection are reduced, and light collection efficiency is improved. Furthermore, in the present embodiment, since the hologram element 14 is used as the color separation means, an inexpensive projection type liquid crystal display device can be realized.

Further, according to the method of manufacturing a hologram element according to the present embodiment, hologram element 15 having the above-described color separation function can be easily manufactured. Further, by adjusting the wavelength of the object light at the time of creating the hologram to the light source spectrum of the set (optical system), there is an effect that the emission energy can be used efficiently.

Although the present invention has been described with reference to the embodiment, the present invention is not limited to the above-described embodiment and can be variously modified. For example, in the above embodiment, in the process of manufacturing the hologram element 14, red, green,
Although multiple exposures are performed in the order of blue, the order of arrangement is determined by the angle of incidence in the manufacturing process, so the order is arbitrary. Further, the hologram element 14 may be manufactured not by the multiple exposure method but by the collective exposure method.

In the above embodiment, the liquid crystal display element 15 having a delta (triangle) pixel arrangement has been described. However, another liquid crystal display element 15 (for example, a mosaic arrangement) may be used. In this case, interference fringes of the hologram element 14 may be formed according to the pixel arrangement.

Further, in the above-described embodiment, an example has been described in which a transmission type hologram element in which diffracted light is emitted on the side opposite to the light source with the hologram surface as a boundary is applied. A hologram element of a mold type can also be used. In this case, the reference light may be incident from a direction conjugate with the reference light when the transmission hologram element is manufactured. Further, in the above-described embodiment, the interference fringes are formed by using the laser light in the process of manufacturing the hologram element. However, light other than the laser can be used as the reference light and the object light.

In addition, in the above embodiment, the interference fringes of the hologram element 14 are optically formed by two-beam interference, but a desired hologram interference fringe can be obtained by a computer. In this computer generated hologram, a hologram element similar to that in the above embodiment may be manufactured by adding the conditions in the above embodiment at the time of calculation.

[0027]

As described above, according to the method for manufacturing a hologram element for a projection type liquid crystal display device according to the present invention, when forming interference fringes on a substrate for a hologram element, a reference light for the substrate is used for liquid crystal display. In a plane including a direction corresponding to the first direction of the pixel array in the element, the light is emitted from a direction having an angle corresponding to the incident light of the white light from the white light source. First
The object light when forming the interference fringes corresponding to the pixels of the type arranged in the direction, is irradiated from the direction having an angle according to the pixel arrangement with respect to the reference light in the same plane as the reference light, Object light when forming interference fringes corresponding to other types of pixels arranged in the second direction in a set of pixels of the liquid crystal display element is referred to as reference light in the pixel arrangement of the liquid crystal display element. Irradiation from a direction having an angle corresponding to the pixel array in the second direction realizes color separation suitable for the pixel array of the liquid crystal display element without restricting the configuration of the optical system. At the same time, the microlens as the light condensing means can be formed into a shape having a high light condensing efficiency corresponding to the pixel arrangement, so that the lens processing can be facilitated.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating an overall schematic configuration of a projection type liquid crystal display device according to an embodiment of the present invention.

FIG. 2 is a top view of a light transmission state of a hologram element used in the display device shown in FIG.

FIG. 3 is a side view showing a light transmission state of a hologram element in the display device shown in FIG. 1;

FIG. 4 is a front view illustrating a pixel arrangement (delta arrangement) of a liquid crystal display element used in the display device illustrated in FIG.

5 is a cross-sectional view for explaining a specific configuration of a liquid crystal display element used for the display device shown in FIG.

FIG. 6 is a plan view for explaining a manufacturing process of the hologram element used for the display device shown in FIG.

FIG. 7 is a side view for explaining a manufacturing process of the hologram element.

[Explanation of symbols]

11: white light source, 12: reflecting mirror, 13: condenser lens, 1
4 Hologram element 14a Hologram substrate 15 Liquid crystal display element (LC
D), 16: Projection lens, 17: Screen

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display location H04N 9/31 H04N 9/31 C

Claims (2)

[Claims] 1. A set of a white light source that emits white light and a plurality of types of pixels arranged in a first direction and a second direction orthogonal to each other on the same plane. A liquid crystal display element, which is arranged in a matrix, and a plurality of interference fringes corresponding to a plurality of types of pixels are formed, and white light emitted from the white light source is separated into a plurality of primary color lights according to the pixel arrangement. A hologram element for a projection-type liquid crystal display device, comprising: a hologram element for guiding each of the separated primary color lights to the liquid crystal display element, wherein interference fringes are formed on a substrate for the hologram element. In this case, the reference light with respect to the substrate has an angle corresponding to incident light of white light from the white light source in a plane including a direction corresponding to the first direction of the pixel array in the liquid crystal display element. And irradiating the object light when forming interference fringes corresponding to the type of pixels arranged in the first direction in the set of pixels of the liquid crystal display element in the same plane as the reference light. Irradiate the reference light from a direction having an angle corresponding to the pixel arrangement, and form interference fringes corresponding to other types of pixels arranged in a second direction among a set of pixels of the liquid crystal display element. A projection type liquid crystal display characterized by irradiating the reference light with an object light at a time corresponding to an angle corresponding to a pixel arrangement in a second direction of a pixel arrangement of the liquid crystal display element. Method for producing hologram element for apparatus. 2. A first primary color pixel and a second primary color pixel, wherein a pair of pixels constituting the liquid crystal display element are arranged adjacent to each other along a first direction of a pixel array. A third primary color pixel arranged along the second direction so as to form a triangle with the first primary color pixel and the second primary color pixel; 2. The method of manufacturing a hologram element for a projection type liquid crystal display device according to claim 1, wherein the hologram element for a projection type liquid crystal display device has a configuration in which one micro lens as a light condensing means is provided corresponding to a set of pixels.