JP2003248181A - Reflective spatial light modulator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To operate an image display device of a high resolution using an optical axis shift element and a reflective light valve by reducing unevenness in a surface with reliability at a lower cost. <P>SOLUTION: A pixel as a spatial light modulation element has a reflective concave surface structure 1, an embedded layer 2 made of a translucent member, a liquid crystal layer 4, a reflecting electrode 6 provided between the structure 1 and the layer 2 so that a planarized layer 3 in which the upper surface is planarized is provided on the layer 2. An incident luminous flux 10 is incident on a concave reflecting mirror 1 through the layer 4 and the layer 3, reflected and condensed by the mirror 1 to form a new contracted pixel 12 in which a condensed state, i.e., a reduced pixel size of the pixel is formed near a focus (f). <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spatial light modulator which realizes optical modulation of a high spatial frequency, an optical exchange switch for optical communication using the spatial light modulator, a projector for image display, and the like. The present invention relates to a head mounted display, and further to an optical information processing device using this spatial light modulator.

[0002]

2. Description of the Related Art Currently, as image display devices (displays), there are CRTs, liquid crystal displays, plasma displays, projectors and the like. These image display devices are required to display an image such as a natural image such as a photograph or a text mainly composed of characters with higher definition and to display on a larger screen.

This appears in the number of pixels and the screen size, which are the scales showing the performance of image display devices in the market.
The number of pixels is now XGA (1024 x 768 dots), SX
GA (1260 x 1024 dots), SXGA + (14
00x1050 dots, QXGA (1600x120)
(0 dots). As for the screen size, with the increase in the number of pixels, the current mainstream 14, 15
It is suitable for increasing the size from inches to 20 inches and 24 inches. A high-definition, large-screen display is required to have a smaller pixel size and a larger total number of pixels.

Among the displays, a projector forms an image by an image display device in which a large number of fine pixels called a liquid crystal spatial light modulation element (liquid crystal light valve) utilizing spatial light modulation by liquid crystal are arranged, and the image is formed by a projection lens. The method of projecting on the screen is used. The pixel shape is square or rectangular, and the size is 1
The sides are several tens to several tens of μm and several tens of μm. This pixel size determines the high definition of the image, and the finer the pixel, the higher the resolution of the image can be realized. Further, it is necessary to increase the number of pixels in order to cope with a large screen.

Liquid crystal light valves are roughly classified into transmissive light valves and reflective light valves. In the transmissive light valve, a thin film transistor (T
Areas such as FT) that do not contribute to image formation cannot be miniaturized,
Even if the pixels are miniaturized, the area occupied by these pixels becomes relatively large, and there is a problem that the aperture ratio decreases. On the other hand, in the reflection type light valve, the pixel electrode (reflection electrode)
Since it is possible to form a wiring portion underneath, the aperture ratio or reflectance can be improved.

However, in order to switch the liquid crystal layer, a liquid crystal is used in the case of using a ferroelectric liquid crystal for a surface stabilizing structure or in the case of using a nematic liquid crystal for a vertical alignment mode or a primary TN structure. The layer thickness needs to be about 1 micron, and a pixel size of about 10 microns can be realized, but the contrast, gradation, and uniformity are maintained at high quality, and smaller than 5 to 7 micron. It is very difficult to realize the pixel size of. There is also a method of increasing the number of pixels by increasing the size of the liquid crystal light valve itself, but this increases the cost of the liquid crystal light valve exponentially and at the same time increases the size of the optical system, resulting in higher cost. Image display device.

Therefore, an image display device which realizes high resolution by increasing the number of pixels by time division by providing an element for shifting the optical axis when projecting a liquid crystal light valve is disclosed in Japanese Patent Laid-Open No. 4-113308. Japanese Patent No. 2939826 (Nippon Telegraph and Telephone Corporation) discloses that by using two sets of an optical element capable of rotating a polarization direction and a transparent element having a birefringence effect with their optical axis shift directions orthogonal to each other, An apparatus for increasing the resolution by 2 times and 2 times in total and 4 times in total is shown. Further, JP-A-5-289044 (Matsushita Electric Industrial Co., Ltd.) and JP-A-6-32432.
Japanese Unexamined Patent Publication No. 0 (Sony Corporation) discloses a device which interpolates scanning lines and doubles the density in the vertical direction when interlaced driving is performed. Further, Japanese Patent Laid-Open No. 9-230329 discloses an apparatus capable of realizing a Δ (delta) array by shifting an optical axis.

As the optical axis shift element other than the optical element capable of turning the polarization direction and the transparent element having the birefringence effect, a display panel (light valve or spatial light modulator) is directly used by using a swing mechanism. Shifting-Patent application
No. 313116 (Nippon Telegraph and Telephone Corporation), Japanese Patent Laid-Open No. 6-20834, which uses rotating plates having different angles in the circumferential direction.
No. 5 (Nippon Victor Co., Ltd.), Japanese Patent Laid-Open No. 6-324320 (Sony Co., Ltd.), which vibrates optical parts such as lenses and mirrors.

Further, Japanese Patent Application Laid-Open No. 09-054554 discloses a method of condensing light with a condensing lens to a size smaller than a relatively large aperture of a transmissive liquid crystal panel when the optical axis is shifted to achieve high resolution. Has been done. Specifically, a transmissive liquid crystal light valve having a specific opening and a microlens having a circular outer shape that further reduces the pixel size than a small opening generated by being restricted by an active element facing the pixel are shown. ing.

Further, in Japanese Patent Laid-Open No. 09-054554, the operation and action when the resolution is doubled in one direction by a projection enlarging device using a liquid crystal light valve and an optical axis shift element. Is shown in comparison with the conventional example, and in the case of the conventional configuration example, the pixel is inevitably slightly reduced by the active element due to the aperture smaller than the pixel pitch, but the beam profile in this case is Even if the pixel has a rectangular shape and the resolution is increased by shifting the optical axis in such a pixel, the shifted pixels overlap with each other, and the brightness of the overlapping portion increases stepwise, so that the resolution cannot be improved. On the other hand, in the invention described in Japanese Patent Laid-Open No. 09-054554, a rectangular beam profile corresponding to the case of a circular shape which becomes a focused pixel is shown, which is larger than the pixel pitch. By being small,
When the optical axis shift element is used, the pixels do not overlap when the optical axis is shifted, and the resolution is improved.

FIG. 16 shows the above-mentioned Japanese Patent Laid-Open No. 09-054554.
FIG. 2 is a schematic configuration diagram for explaining an example of the display device described in Japanese Patent Publication No. JP-A-2003-242242.
A condensing optical system (microlens, Fresnel lens, etc.) 102 is disposed on the incident light beam 101 side (backlight side) of the display focus surface of the, and the condensing optical system 102 includes a mosaic display device 103. Each display pixel opening 10
The minute lens portions 102a corresponding to 3a are arranged. The minute lens portion 102a narrows the incident light beam 101 from the backlight side to a condensing pixel size 101a smaller than the display pixel opening 103a on the display focus surface of the mosaic display device 103, and emits the outgoing light beam 104. The light is emitted to the observer side or the screen side.

FIG. 17 is a diagram showing a luminance state in which a half-line non-interlaced display not implementing the display device shown in FIG. 16 is changed to a full-line interlaced display by using optical wobbling. The vertical axis represents the pixel position. As the display signal, a black-and-white repeating horizontal streak pattern for each line is assumed. Since it is a half line, the ODD field has a white level and the EVEN field has a black level. It can be seen that the portion of the brightness level 0 is a mask portion between pixels, and the black-and-white repeating signal for each line is reproduced as compared with the case of half-line non-interlaced display. When the opening is formed wider than the mask portion to improve brightness, the pixels of the original field and the pixels of the wobbled field appear to partially overlap with each other, and the vertical resolution is halved. .

FIG. 18 is a diagram showing a luminance state when the condensing pixel size is reduced by using the condensing optical system shown in FIG. 16, and the condensing pixel size is reduced as compared with the case of FIG. Since the display pixel size is reduced, there is no overlap between the display pixels, the resolution is improved, the brightness level is improved, and the contrast is improved. Therefore, it is possible to obtain an image quality with the same resolution and contrast as the full line double speed display. Considering moving images, the image quality is better than that of full-line double-speed display because it is interlaced by optical wobbling.

However, the above-mentioned Japanese Unexamined Patent Publication No. 09-0545
The configuration disclosed in Japanese Patent Publication No. 54 is characterized in that a microlens array, which is a condensing optical system in which condensing functional portions corresponding to the number of display pixels are arranged, is arranged on the light source side of the display pixels. However, in a normal configuration of a reflection type light valve, the illumination light condensed by the microlens array at the time of incidence is the same as that at the time of emission. The pixels cannot be reduced because they are magnified by the microlens array. Japanese Unexamined Patent Publication No. 09-054554 does not consider the problem that occurs in such a reflective light valve, and does not describe the solution thereof.

On the other hand, in a reflection type light valve, an image display device in which a microlens is provided for each pixel in order to improve light utilization efficiency is disclosed in Japanese Patent Laid-Open No. 11-258585.
Japanese Patent Publication No. 2001-215531 and the like. Japanese Patent Application Laid-Open No. 11-258585 discloses a conventional example of a reflective light valve in which a microlens is provided on a reflective electrode, and the focal length and the distance between the microlens and a pixel are focused. According to the invention,
Similar to Japanese Patent Publication No. 001-215531, the effect of disclination is reduced, and at the same time, the effective reflection area ratio of the pixel is brought close to 100% to improve the light utilization efficiency, thereby realizing an image with higher brightness and higher quality. It is an object. In Japanese Patent Laid-Open No. 11-258585, f> t is a favorable condition for realizing a high-luminance, high-quality image, where f is the focal length of the microlens and t is the distance between the microlens and the reflective electrode. , F = 2t is the most preferable. This is because the configuration satisfying this condition is efficiently taken into the projection lens to generate the emitted light from the microlens and improve the utilization efficiency. Also, f =
It is described that under the condition of 2t, a spot having a size of 1/2 of one side of the microlens (square) is formed on the reflective electrode.

FIG. 19 is a diagram showing an example of a display device described in Japanese Patent Laid-Open No. 11-258585, which is a light source 111.
The light from is incident on the liquid crystal display device 113 by the beam splitter 112, is reflected by the reflective electrode 114 when the liquid crystal display device 113 is in the ON state, reaches the projection lens 115 through the beam splitter 112, and is displayed on the screen 116. Projected.

However, the above-mentioned Japanese Patent Laid-Open No. 11-2585.
The invention described in Japanese Patent Publication No. 85 is aimed at improving the light utilization efficiency, and does not consider a pixel size reduction element in the case of combining an optical axis shift element, and uses the optical axis shift element in this configuration. Cannot be used as a high-resolution image display device. This is because Japanese Patent Laid-Open No. 11-2585
According to Japanese Patent Laid-Open No. 85, the range of F that satisfies the F value of the illumination system = the F value of the microlens = the F value of the projection lens is optimal so that the pixels are imaged at the same magnification. Furthermore, f =
When the relationship of 2t is established, the refractive index between the microlens and the reflective electrode is 1, and when the illumination light incident on the reflective electrode first enters, the microlens almost functions as a field lens. Therefore, when the incident illumination light is reflected by the reflective electrode serving as a pixel, is emitted in the opposite direction, and is incident on the microlens again, the reflected light is transmitted to the aperture which is the size of the microlens and has a size of approximately 100%. Therefore, light can be transmitted without loss. That is, no pixel reduction is performed.

In such an optical configuration, three F
Since the F values of the projection lenses do not have to be made smaller because the values are almost the same, the effect of reducing the pixels does not occur, and the size of the pixels when the emitted image light re-enters the microlens is , It is almost the same as the microlens, that is, the magnification is the same, and no consideration has been given to the effect on pixel reduction when combined with the optical axis shift element.
This is because if the optical axis shift is not performed and the pixels are reduced so that gaps are formed between the pixels, the smoothness of the image is rather reduced.

Further, in order to improve the light utilization efficiency in the reflection type light valve, a microlens is provided on the light source side of each pixel, and at the same time, a microlens or a micro condenser mirror is provided on the substrate side. An image display device is disclosed in Japanese Patent Laid-Open No. 9-90310.

FIG. 20 is a perspective constitutional view for explaining an example of the reflection type liquid crystal device described in the above-mentioned Japanese Patent Laid-Open No. 09-90310, FIG. 21 is a sectional constitutional view, and 121 is a first light collecting means. 21 is a front light incident side transparent substrate having a micro lens 121a, and 122 is a rear light incident side transparent substrate having a pixel electrode 122a. These are bonded by an adhesive 125 as shown in FIG. There is. 123 is the second
Is a reflective electrode having a reflective electrode 123a, which is a light-collecting means, and is mainly composed of liquid crystal.
The transparent electrode 122a is formed on the surface that is in contact with or close to.

In the reflection type light valve disclosed in Japanese Patent Application Laid-Open No. 09-90310, which improves the light utilization efficiency, the lens 121 is provided with a specific illumination angle both at the time of incidence and at the time of emission. At the same time as a field lens, the lens 121
By configuring the microlens or the micro-condensing mirror 123 provided on the opposite side to a relay lens-like configuration, there is almost no loss of light and spread of the emission angle with respect to the illumination angle, and a microlens corresponding to each pixel is configured. It is supposed to be possible.

However, the above-mentioned Japanese Unexamined Patent Publication No. 09-9031.
In JP-A-0, in order to improve light utilization efficiency,
Since it is important that the incident illumination angle and the outgoing angle are approximately the same and that there is no vignetting in the optical system that uses the lens size as a stop, the outgoing light reflected to the full size of the lens 121 is In consideration of transmission, no consideration is given to reducing the pixel size when an optical axis shift element is used. Therefore, the micro condenser mirror 12
3 also has a configuration in which a lens 121 serving as a field lens is arranged at a position about twice the focal length as a relay lens. Since this is an equal-magnification image formation, the resolution is increased by the optical axis shift element and the pixel is increased. It does not consider reducing the size at all.

[0023]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has been conventionally performed in the case of realizing a high-resolution image display device using an optical axis shift element and a reflection type light valve. The cost is lower and the reliability is higher than that of a high-resolution image display device using a reflective light valve in which a circuit for driving the pixels, a substrate having a reflective surface, and a counter substrate having a microlens are attached to each other and an optical axis shift element. At the same time, it is possible to provide an image display device capable of further reducing in-plane non-uniformity, and further, an image display in which a conventional microlens is allowed to act in the path of irradiation light before transmission of the switching layer. An object of the present invention is to provide an image display device having higher resolution and brighter visibility than the device.

[0024]

The present invention has a driving circuit, a substrate having a reflecting surface, and a microlens for deforming a pixel profile, which are required in a high-resolution image display device using a conventional optical axis shift element. High-precision alignment between the counter substrate and the counter substrate having the microlenses is achieved by providing an optical element that eliminates the microlenses from the counter substrate and reflects on the circuit having the driving surface and the substrate having the reflecting surface and at the same time deforms the pixel profile. , The substrate having the circuit and the substrate having the circuit are made alignment-free, and instead of causing the pixel profile deforming element composed of a conventional microlens to act prior to the transmission of the switching layer in the path of the irradiation light, the pixel profile deforming element is used. To act after the first transmission of the switching layer in the path of the illuminating light Ri was resolved.

According to a first aspect of the present invention, a light source that emits light, an irradiation optical element that shapes the light from the light source into irradiation light, and optically modulates the incident irradiation light and reflects the irradiation light. Reflection-type spatial light having a plurality of light modulation elements arranged on substantially the same plane for emitting the light and emitting light emitted from the plurality of light modulation elements in a spatial coordinate manner. In the modulator, the light modulator is
It is characterized in that each of the light modulation elements has a reflection type light flux profile deforming element that reflects the irradiation light and deforms the light flux profile of the emitted light emitted by the reflection.

A second invention is characterized in that, in the first invention, the reflection type light flux profile deforming element is an optical element having a concave mirror surface.

A third invention is characterized in that, in the first invention, the reflection type light flux profile deforming element is an optical element having a concave mirror surface having a curved surface.

In a fourth invention according to the first, second or third invention, a transparent material having a refractive index n of 1.6 or more is provided on the entrance / exit side of the concave mirror surface of the reflection type light flux profile modifying element. It is characterized in that it has an embedded member which is a member and has a shape to be embedded in the mirror surface.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the aperture diameter of the concave mirror surface having the curved surface of the reflected light beam profile deforming element is d, and the average curvature of the concave mirror surface is d. Where r is 2.2 / (m /
2) <r / d <17.9 / (m / 2) (where m is the number of modulation steps of the optical path modulator).

In a sixth aspect of the present invention, in any one of the first to fifth aspects, when the F number of the concave mirror surface having the curved surface of the reflected light beam profile deforming element is Fr number, 1.1 /(M/2)<n×Fr<8.9/(m/2)
(However, n is the refractive index of the embedded member, and m is the number of modulation steps of the optical path modulator.)

In a seventh aspect of the present invention, in any one of the first to sixth aspects of the invention, the F-value of the concave mirror surface having the curved surface of the reflected light beam profile deforming element is set to an Fr value, and the spatial light modulating element is provided. When the F value of the incident irradiation light is a Fi value, 0.27 / (m / 2) <n × (Fr / F
i) <2.2 / (m / 2) (where n is the refractive index of the embedding member and m is the number of modulation steps of the optical path modulator).

An eighth invention is characterized in that, in any one of the first to seventh inventions, the reflection type light flux profile modifying element has an optical element in which a mirror surface and a microlens are integrated. Is.

In a ninth aspect based on the eighth aspect, the microlens of the reflection type light flux profile modifying element is
It is characterized by being a microlens having a curved surface.

A tenth invention is characterized in that, in the eighth invention, the microlens of the reflection type light flux profile modifying element has a microlens having a refractive index distribution member.

An eleventh invention is characterized in that, in any one of the first to tenth inventions, the reflection type light flux profile modifying element is an optical element in which a mirror surface and a micro prism are integrated. Is.

A twelfth invention is characterized in that, in the fourth or ninth invention, the microlenses or the microprisms of the reflection type light flux profile modifying element have a diffraction grating.

A thirteenth aspect of the present invention is the light modulating element according to any one of the first to twelfth aspects, wherein the light modulating element has a light modulating layer that modulates light by changing the transmittance or changing the deflection angle. On the other hand, the reflection-type luminous flux profile deformation element is provided on the side opposite to the incident direction of the irradiation light.

A fourteenth invention is the thirteenth invention, wherein
A flattening layer is provided between the reflective light flux profile modifying element and the light modulation layer.

The fifteenth invention is the fourteenth invention, wherein
It is characterized in that a conductive layer is provided between the flattening layer and the light modulation layer of the reflection type light flux profile deformation element.

In a sixteenth invention according to any one of the first to twelfth inventions, the light modulation element has a light modulation layer for modulating light by a change in transmittance or a change in deflection angle, and the reflection type light flux. The profile deformation element is integrated with the light modulation layer.

A seventeenth invention is characterized in that, in any one of the first to fifteenth inventions, the light modulation element has a light shielding layer having an opening.

In an eighteenth aspect of the present invention according to any one of the first to seventeenth aspects, the full width at half maximum of the luminous flux profile of the emitted light emitted from the light modulation element is smaller than the original pitch of the light modulation element. It is characterized in that it has an imaging lens for forming an image of outgoing light at a position different from the position of the light modulation layer of the light modulation element.

In a nineteenth aspect based on any one of the first to seventeenth aspects, the full width at half maximum of the luminous flux profile of the emitted light emitted from the light modulation element is smaller than the original pitch of the light modulation element. It is characterized in that it has a virtual image forming lens for forming a virtual image of emitted light at a position different from the position of the light modulation layer of the light modulation element.

[0044]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (Embodiment 1) FIG. 1 is a diagram for explaining Embodiment 1 of the present invention, in which an optical axis shift element is used to increase the resolution of an original reflective light valve. FIG. 3 is a schematic view of a cross section of a reflection type light valve having, for each pixel, a concave mirror that serves as a pixel profile deforming element of the image display apparatus. In FIG. 1, only the basic configuration is shown, and a pixel serving as a spatial light modulator includes a reflective concave surface structure 1, an embedded layer 2 that is a layer made of a translucent member, and a liquid crystal layer 4.
A reflective electrode 6 is provided between the reflective concave surface structure 1 and the burying layer 2, a flattening layer 3 having a flattened upper surface is provided on the burying layer 2, and the flattening layer 3 is provided on the flattening layer 3. In addition, below the liquid crystal layer 4, there is an additional transparent electrode 7. A counter substrate 5 is provided on the liquid crystal layer 4, and a transparent electrode 8 is separately provided on the liquid crystal side of the counter substrate 5. Although not shown, the transparent electrode 7 and the reflective electrode 6 are separated for each pixel and are electrically connected to each other by a through hole filling member 9. Here, the radius of curvature of the concave reflector 1 is r, and the refractive index of the buried layer 2 is n. As the substrate of the reflective concave mirror 1, Si, a SiO ₂ substrate with high temperature pSi, or the like is used. A thin film of metal such as Al is used for the reflective electrode 6, and a thin film of ITO is used for the transparent electrode 7.

FIG. 2 is a diagram for explaining the outline of the operation in the case of the first embodiment shown in FIG. 1, and FIG.
FIG. 2 is a diagram showing the operation of irradiation light in FIG. 2 and a state in which an image of a pixel is formed by a reflecting concave mirror. In FIG.
As for 0, only parallel light is shown. The incident light flux 10 is transmitted through the liquid crystal layer 4 and the light-transmitting flattening layer 3 and is incident on the reflection concave mirror 1, is reflected and condensed by the reflection concave mirror 1, and is in a condensed state of a pixel near the focus f, that is, A new reduced pixel 12 with a reduced pixel size is formed. In FIG. 2, the reduced pixels 12 are spread in fact that the light flux is spread by the light source or the device, that is, the illumination angle (divergence angle) θi.
This is because there is n (see FIG. 3). From a geometrical point of view, the size of the reduced pixel has a size corresponding to the illumination angle and the focal length. In addition, the reduced pixel becomes larger according to the aberration. Furthermore, when the pixel profile of the deformed reduced pixel is projected on the screen using the projection lens, the pixel profile is further deformed in accordance with the transfer function of the projection lens. However, by optimizing these, in the vicinity 11 of the focal position of the reflective concave mirror 1, it is possible to form a condensed state in which the light emitted from the pixel is pixel-reduced.

FIG. 3 is a diagram showing the relationship between the maximum angle θin at the time of incidence on the pixel and the maximum angle θout at the time of emission. θi
Although n is determined by the irradiation optical system and has a constant value for the incident light to be irradiated, θout changes depending on n and r. In FIG. 3, θout is an angle that is about half the spread of the light flux, but by reducing the pixel size, it is about ½.
In the case of, the angle (± θout) is about twice this. Therefore, in order to achieve high resolution while maintaining the light utilization efficiency when the pixel size is reduced to about 1/2 by using the optical axis shift element and the pixel reduction element, the projection lens is used When projecting the emitted light, it is preferable to use a projection lens having an F value that is about 1/2 times that of the conventional one.

Further, as shown in FIG. 3, since the pixel profile in the condensed state where the pixel size is reduced is near the focus of the optical element, the angular distribution of the irradiation light to the pixel also has a great influence. Furthermore, the reduction ratio of the pixel greatly varies depending on the outer shape of the pixel itself, the curvature profile of the concave mirror, the characteristics and the positional relationship of the projection lens, and it is preferable to optimize these.

Further, when the emitted light is subjected to pixel reduction by the concave mirror, it is not necessary to simply reduce the pixel size to 1/2. When using an optical axis shift element for high resolution,
The transformed pixel profile is simply the pixel reduction factor,
Visibility such as image resolution and smoothness is not determined, and even at the same pixel reduction ratio, if the pixel profiles are different, the visibility may be greatly different. In addition, even if the pixel size is not ½, a large difference in visibility may not be recognized.

FIG. 4 is a diagram for explaining the second embodiment of the present invention, in which the pixel profile emitted from the reflective concave mirror (emitted from the pixel) is modified by the reflection type light valve in the first embodiment, and the pixel is changed. An operation of increasing the number of pixels (image of pixels) by an element in which a pixel whose size is reduced modulates (spatial shift) the optical path is shown. In this example, the piezo elements 22 and 23 are used as means for modulating the optical path of the light emitted from the pixel of the spatial light modulation element 21 (viewed perpendicularly to the optical axis). This is to mechanically move the spatial modulation element 21 itself by using the piezoelectric elements 22 and 23. Since the element itself moves, the pixel also moves. If a piezo element is used, the pixel size is 10 μm
Even if it is m or less, the optical path can be shifted less than that. This can be achieved by installing the piezo elements 22 and 23 vertically (y-axis direction) 25 and horizontally (x-axis direction) 26 on the spatial light modulator 21 and the jig 24 and periodically moving them. Note that z
The axis is perpendicular to the plane of the paper and coincides with the optical axis.

FIG. 5 shows a pixel whose pixel size is reduced by modifying the pixel profile emitted from the reflective concave mirror by the reflective light valve in Embodiment 1 of FIG.
FIG. 11 is a diagram showing an operation of forming a high-resolution image by being time-divisionally projected on the screen by the optical axis shift element in the second embodiment. Here, the reduction rate α of the pixel size by the microlens array is 1/2. Pixels of the spatial light modulator are square, and a square reduced image is obtained assuming that the pixels are ideally reduced. First, letting (A) be the initial state that is not moving, and (B) be the state in which the pixel size of the spatial light modulator is shifted by 1/2 in the y direction. For example, if the pixel size is 14 μm, then 7 μm. = Δx, Δy. The state in which the pixel size is shifted by 1/2 in the x direction from (B) is (C), and subsequently, the pixel size is shifted by 1/2 in the direction opposite to (B) (displayed as minus or −). The state is (D), followed by (E), the state shifted in the opposite direction to (C), and (F) the state finally shifted by 1/2 of the pixel size in the y direction. Then, the state of (A) is restored. As a result, if these shift cycles are fast, the image will not flicker, and flicker will not be felt.
It is possible to realize a high definition image (G) in which the size of one side of the pixel is ½ and the density is four times. Further, in this example, since the spatial light modulator and the optical path modulator are one device, there is no need to expand the optical system and insert the optical path modulator, which leads to downsizing of the apparatus. In the above example, the movement is performed in two directions of x and y, but the shift may be performed in only one of x and y. In this case, the pixel is 2
Doubled. Also, α is set to 1/3 and the shift amount is 1 /
If it is 3, a 9 × increase in the number of pixels can be expected with 3 × 3.

The optical axis shift element shown in FIG. 4 may be an element that shifts the optical path in space coordinates, and in addition to directly mechanically moving the reflection type light valve, a liquid crystal which is a birefringent material. Using the optical element using, the optical axis may be parallel-shifted, the optical axis may be deflected, or the optical axis may be parallel-shifted and the optical axis may be deflected at the same time. Further, it is possible to mechanically displace a transparent member having a wedge shape or obliquely arranged and having different optical path lengths.

FIG. 6 is based on the operation shown in FIG.
Pixels whose pixel size is reduced by changing the pixel profile emitted from the reflection concave mirror by the reflection type light valve in the first embodiment of the present invention are projected on the screen by the optical axis shift element in the second embodiment of FIG. 4 in a time division manner. 3 is a third embodiment of the configuration of an image display device that realizes high-resolution image display, and relates to a high-definition image projection device (projector) using the high-definition image display device. As an example, an example of a single-plate type projector using one reflective spatial light modulator is shown. The light emitted from the white light source 31 is first made uniform in illuminance by a homogenizing optical element (light integrator) 32 such as a fly-eye lens. Next, a color separation device 33 such as a color wheel separates the three colors of red, green, and blue. When a color wheel is used, it is not separated into red, green, and blue at the same time, but is separated in time series into red, green, and blue. Next, each color enters the polarization beam splitter 35, is reflected by the pixels of the spatial light modulator (reflection type liquid crystal light valve) 34, passes through the polarization beam splitter 35, and is finally projected by the projection lens 36, and the screen 37 A high-definition image is formed on.

As the spatial light modulator, the first embodiment shown in FIG. 1 is used.
In addition to the reflective light valve LCOS described in
A reflective deflection element may be used by using the MEMS technique like DMD. Further, the method of using the spatial light modulator is not limited to the single plate type shown in FIG. 6, and may be a three plate type or a two plate type. Since the spatial light modulation element is combined with the optical axis shift element, it is preferable that it has a high-speed response.

Further, as in the projector shown in FIG. 6, other than a device for displaying a high-resolution image in which a reduced pixel having a modified pixel profile is enlarged by image formation satisfying a conjugate relationship using a projection lens. An image display device that magnifies and displays an image by magnifying as a virtual image using a magnifying lens for forming a virtual image, such as a magnifying glass, may be used. As a result, a viewfinder of a video camera, a head mounted display, a small display for a cellular phone, etc. can be realized.

When high-resolution display is performed by combining the optical axis shift element and the reflection type light valve in the present invention and using the reflection type pixel reduction element, the pixel reduction by the microlens on the conventional counter substrate is performed. The difference in operation between the case of using and the case of using will be described below. When the pixel profile is modified in the reflective light valve with the configuration shown in FIGS. 1, 4 and 6 of the first embodiment,
Unlike the case where a conventional microlens is provided on the light source side,
Since there is no optical element required for alignment on the substrate facing the silicon substrate with the reflective electrode, there is no need for position adjustment when bonding with the opposing substrate, and alignment-free, so an expensive overlay device during assembly. It is not necessary to use an anti-vibration device or the like, and the yield of assembly is greatly improved, so that the cost can be significantly reduced. Further, the pixel profile does not change even if the horizontal displacement with respect to the counter substrate occurs after the assembly, so that the reliability is very excellent. Further, since there is a difference in expansion coefficient between the glass substrate and the silicon substrate which are usually used as the counter substrate, there are great restrictions on the process temperature at the time of production and the use environment as a product. With a diagonal 1 inch silicon substrate and ordinary optical glass,
Even with a temperature change of 10 degrees, a difference in expansion of several micron is generated between the ends, and further 120 to 15 of adhesive curing
There was a difference in expansion due to a positional deviation of 10 microns or more at a temperature change of 100 degrees in the 0 degree process. These are directly misaligned, damage the liquid crystal spacers, or warp to deteriorate the characteristics of the reflective light valve. However, the influence of the positional deviation can be eliminated, the manufacturing can be performed at a lower cost, and at the same time, the reliability in a severe environment such as a cold region or the inside of a vehicle in the summer can be significantly improved. Furthermore, even if a large 2-inch reflective light valve is used, it will not affect the absolute positional deviation, but even if the reflective light valve is made larger, the resolution will increase. Will be able to improve.

Further, in the structure shown in FIGS. 1 and 4 and 6 of the first embodiment, when the pixel profile is modified in the reflection type light valve, unlike the case where the conventional microlens is provided on the light source side, silicon is used. Since an element that deforms the pixel profile is provided on the substrate side, an optical element that deforms the pixel profile after the illumination light is first transmitted as it is, with a liquid crystal layer that is switched by polarization rotation in combination with a polarization separation element as an opening And is then transmitted through the liquid crystal layer again. Therefore, even if the conventional microlenses on the light source side are provided with a light condensing function in order to reduce the initial pixel profile, they may be enlarged on the way back and may not be reduced. Also,
The focal length of the microlens can be changed to effectively operate one lens both in the forward and backward directions to reduce pixels, but the illumination angle, substrate thickness, and microlens structure are limited. In addition, since the lens power is inevitably the same on the forward path and the backward path because it is a single lens, the resolution and light utilization rate when changing the pixel profile are not sufficient, and it is brighter. It is also not possible to use illumination angles or darker projection lenses.

On the other hand, the microlens of the present invention does not work up to the first liquid crystal layer in the outward path, but can work in the optical path thereafter, so that the pixel profile can be deformed with higher resolution. In addition, it is designed to improve the light utilization efficiency. Further, it becomes possible to realize an image profile having a shape that cannot be realized by the pixel profile deformation by the conventional microlenses provided on the counter substrate, and it is possible to realize higher resolution. In addition, since a transmissive microlens, in particular, a single lens having a very small F value can be made to have no large chromatic aberration in the case of a reflecting mirror, the pixel profile color variation can be greatly reduced in this respect as well. It becomes possible to realize higher resolution than ever before.

Further, the effective aperture as the optical system is the microlens of the counter substrate in the conventional method, whereas in the present invention, the size of the pixel of the liquid crystal layer itself is the aperture. For this reason, in the past, the crosstalk between adjacent pixels was greatly influenced by the characteristics of the periphery and adjacent portions of the microlenses provided on the counter substrate, and the resolution was reduced, while the crosstalk between pixels adjacent to each other in the liquid crystal itself. Since it is possible to improve the resolution by reducing the number of pixels, it is possible to easily reduce the crosstalk between adjacent images by providing the electrode pattern and the light shielding layer, and it is possible to realize a higher resolution image.

Further, in FIG. 1, the concave mirror is not limited to the spherical mirror, but may be an aspherical mirror or a free-form mirror. Moreover, you may use combining the planar mirror which does not have a curved surface. By using two mirrors symmetrically facing each other in a V-shape diagonally, the pixel profile can be deformed in one of the horizontal and vertical directions to reduce the pixels. Further, it is preferable to use three or more sheets because the pixels can be reduced more effectively. Further, by using four mirror surfaces diagonally opposed to each other in two directions like an inverted pyramid structure, pixels can be reduced in two directions, horizontal and vertical. Furthermore, by increasing the number of mirror surfaces, the pixels can be effectively reduced.
Since it is not necessary to form a curved surface structure, these can be relatively easily manufactured by using the MEMS technology when the number of mirror surfaces is about several, and the cost is lower.

In FIG. 1, since the liquid crystal layer 4 does not need to be formed in a concave shape by having the burying layer 2, it is not necessary to form a convex shape on the counter substrate, alignment is not necessary, and assembly is very easy. It will be easier. Further, by embedding a transparent dielectric material instead of forming an air layer, the refractive index becomes at least 1.3 or more, so that the focal length f (absolute value) of the concave mirror has a curvature r and a diameter d.
And the refractive index is given by f = r / (nd), so even if the focal length of the concave mirror has the same curvature,
It is possible to make it smaller than 10%, and it is possible to greatly reduce various aberrations such as spherical aberration on the axis of the concave mirror, off-axis astigmatism and coma, and to greatly reduce the pixel reduction ratio. As a result, higher resolution can be achieved.

In FIG. 1, a flattening layer 3 made of another transparent material is provided on the buried layer 2, and the flattening layer 3 has its upper surface flattened by chemical polishing. On the flattening layer 3, a transparent electrode and an alignment film are formed, and then a liquid crystal layer is formed. This makes it possible to achieve a liquid crystal layer thickness within plus or minus 1 micron, which is excellent. Contrast and even in-plane uniformity can be realized, and further, uniformity in the panel is improved. The flattening layer 3 may be formed by integrating the buried layer 2 and using the buried layer itself as a flattening layer.

When an electric field is applied to the liquid crystal, the electric field can be directly applied by the reflecting electrode 6 without providing the transparent electrode 7. Since the structure is simple, the cost is low and the reliability is excellent. . However, when the curvature of the concave mirror is small or when the pixel pitch is large, the unevenness difference of the concave member 1 becomes large, and the electric field may not be uniformly applied to the liquid crystal layer 4. Therefore, as shown in FIG.
By separately providing the transparent electrode 7 on the flattening layer 3, it becomes possible to apply a uniform electric field in the pixel to the liquid crystal layer and improve the contrast of the image. The transparent electrode 7 and the reflective electrode 6 are electrically contacted with each other by using a through-hole filling member, and the embedded layer 2 is thinned to directly electrically contact the transparent electrode 7 at the edge portion of the reflective electrode 6. You may.

In the configuration of the first embodiment shown in FIG. 1, in order to quantitatively evaluate the characteristics of the pixel profile, the following evaluation values, namely (1) CTF (Contrast Tr) are used.
transfer function), (2) Reduction rate:
α and (3) utilization efficiency; η were used.

FIG. 7 is a diagram for explaining the CTF. FIG. 7A is a schematic view of the outer diameter shape when the pixel profile is reduced and deformed from the original square by the pixel reduction element. FIG. 7B is a light intensity distribution diagram that is a pixel profile that is a cross-sectional view in the horizontal direction of the paper surface of FIG. 7A. As shown in FIG. 7 (A), 3 is measured or visually recognized.
When one pixel 41 is actually evaluated quantitatively, FIG.
As shown in (B), the pixel profile is not a perfect rectangular pixel profile but a continuous pixel profile, and at the same time, it has a minimum value MIN other than 0. At this time, the maximum value MAX and the minimum value MIN of this pixel profile are defined as shown in Expression (1). CTF = (MAX-MIN) / (MAX + MIN) ... Formula (1)

However, while the normal MTF is a transfer function of a sine wave, here the first waveform is a rectangular pixel wave of a reflection type light valve. Therefore, since the CTF is obtained when the pixels are reduced, the spatial frequency becomes the spatial frequency corresponding to the inverse of the pitch of the original pixel. However, since this CTF is a transfer function of a rectangular wave, the CTF is determined by the MTF characteristics of higher and lower frequencies other than the corresponding spatial frequency.
It does not uniquely correspond to the MTF of a specific spatial frequency. However, from the viewpoint of resolution limit, MT
Almost the same as F, usually at least 20% or more,
The value is preferably 30% or more, more preferably 50% or more. Further, if it is 65% or more, the visibility is recognized almost like the original rectangular wave.

These CTFs were measured by combining a microscope objective lens and a CCD light receiving element via a prism type beam splitter. Further, instead of the microscope objective lens, a projection lens having different MTF characteristics was used, and the CCD was directly arranged on the surface on which the conjugate screen was arranged. As the microscope objective lens, SLWD having a long working distance of Nikon 20 times or 40 times was used by providing an aperture if necessary and controlling the taking NA. The projection lens used was a self-made projection lens. The calculation was performed by removing the dark noise of CCD.

If an ideal optical system is used for a rectangular pixel profile, the image projected on the screen is rectangular, and a sharp and clear image can be realized. However, such an image gives a good result in subjective evaluation in the case of a conventional low-resolution display and a data projector with a small amount of image information. In an image display device that is intended to realize the above, or an image display device that displays image information of a moving image and mainly displays image information, "jagginess" or "gradation discontinuity"
Feeling is generated by subjective evaluation, and does not always give excellent image quality. These affect the image quality in combination with the aperture ratio and the corresponding reduction ratio described below.

The reduction ratio was evaluated by using the full width at half maximum with the same configuration as the optical system for evaluating the CTF. The reduction rate α is defined by the following equation (2). α = Full width at half maximum of pixel profile / Pixel size of spatial light modulator ... Formula (2) However, when a magnifying optical system is used, the reduction ratio α is normalized to 1.0 or 100. When it was%, it was assumed to be the same size without reduction. This reduction rate is important together with CTF as a standard for high definition of an image. From the viewpoint of a high-definition image by pixel reduction, when α is 1.0, it is not reduced at all and cannot be a high-definition image. On the contrary, if the value is too small, this time it is not a profile. It was found that the gap was marked and the image was in an excessively reduced state that could not be a high-definition image.

Then, the relationship between the reduction ratio and the image quality when the image was shifted using the optical axis shift element was tested by subjective evaluation. The reduction rate greatly affects the image quality when the resolution is increased by using the optical axis shift element. Figure 7
From the subjective evaluation of the image based on the profile as shown in (A), the results shown in Table 1 were obtained regarding the reduction ratio and the high definition of the image. Here, with respect to the increase in the number of pixels described above, it is set to 4 times (2 times in the vertical direction and 2 times in the horizontal direction). The image is
Images consisting of pixels with different image profiles of α were evaluated.

[0070]

[Table 1]

Here, ◯ means good, Δ means good, and × means not, and was performed on 10 observers on the basis of a five-step scale, which is a series category method, and 4 or more was evaluated as ○, 3 or more. Is Δ, and 2 or less is x. As a scale of 5 steps, a scale of very good, good, normal, bad, and very bad is used, and gradation, sharpness,
Multiple evaluations regarding noise were made.

When α'is 1.0, the pixel image is not reduced at all and cannot be said to be a high definition image. When α'is 0.8, the effect is not remarkable, but there is a difference compared with when it is 1.0. Therefore, it is considered that the upper limit of α'is around 0.9. But,
It is preferably about 0.35 to about 0.8, and more preferably about 0.4 to about 0.7. In the case of only increasing the definition of the image by pixel reduction, α ′ may be appropriately small, but when increasing the number of pixels, the reduction rate must be a value according to the rate of increase. As in the above example, when the number of pixels is 4 times (2 × 2), it is more appropriate that α ′ is around 0.5, but the number of pixels is 9 times (3 times vertical, 3 times horizontal).
If doubled, this value is large. This is because, since the profile has a shape with a skirt, the pixels are overlapped with each other, the CTF is deteriorated, and the image quality is deteriorated.

When the optical axis shift element shifts the optical axis by a level other than two and is three or more, the number is 0.
It is preferable that the pixel size reduction rate is 8 * 2/3 times. This makes it possible to obtain a convolution image similar to the optical axis shift of 2 times, and reduce the deterioration of resolution due to crosstalk between adjacent pixels even in the optical axis shift of 3 times and 4 times. it can. More specifically, when it is tripled, it is preferably 0.23 or more and 0.53 or less, and more preferably 0.23 or more and 0.46 or less. It is said that the optimum value of α'is about 0.33.

Even if the image is of high definition, good image quality cannot be obtained if the image is dark, and utilization efficiency is also important. Using this as a measure, we defined the usage efficiency η for one pixel. This is how much the energy emitted from one pixel on the pixel array of the spatial light modulation element corresponds to one pixel projected on the screen which is in an image forming relationship at the position where the pixel is reduced and the position conjugate with this. It is the ratio of whether it has reached. Equation (3) shows the definition of efficiency when projected on a screen. η = energy reaching a region corresponding to one pixel on the screen (W) / energy reflected by one pixel on the light valve (W) (3)

When the pixel size is simply reduced by using only the aperture of the light shielding layer, the light use efficiency in the case of 1/2 times pixel reduction, that is, when α = 0.5, is 0.25. That is, since it is 25%, it is preferably at least more. In order to increase the resolution using the optical axis shift element, it is necessary to appropriately improve the values of CTF, α and η.

(Manufacturing / Evaluation Means) The opposite of Example 1 of the present invention.
The flash type light valve can be manufactured as follows.
The silicon substrate backplane for normal LCOS
As is, use the transparent dielectric on this aluminum metal reflective electrode.
The body layer is deposited to a thickness of about 2 microns. Film formation is PCV
SiO by D₂Layer, SiON layer, SiN layer, EB evaporation
And sputtered Al₂O₃Layer, TiO₂Layer, ZnO
A layer or the like is formed. After this, contact at the edge of the pixel
After forming a through hole for the
Ni metal is electroformed. Also, transfer with a gradation mask.
After forming a concave resist layer for copying, dray etch
To form a concave shape of about 0.5 to 2 microns
It After that, after forming an aluminum electrode on the entire surface,
Etching the peripheral part to prevent contact between the elements
Remove more. Then again, this aluminum metal counter
Form a transparent dielectric layer with a thickness of approximately 2 microns on the emitting electrode
It The film is formed by PCVD using SiO 2.₂Layer, SiON layer,
SiN layer, EB evaporation and sputtered Al₂O ₃layer,
TiO₂A layer, a ZnO layer, etc. are formed.

After that, a second through hole for contact is formed in the edge portion of the pixel, and then aluminum metal is electroformed into this portion. Then, after chemical polishing, an ITO electrode is formed on the entire surface, and the peripheral portion is removed by dry etching to prevent contact between pixels. Further, a polyimide alignment film is applied on the ITO film. After that, it can be manufactured by stacking, assembling, injecting, and sealing with a counter substrate similar to a normal LCOS.

In the reflection type light valve of Example 1 of the present invention, the projection image having the structure as shown in FIG. 6 is arranged on the surface enlarged by a microscope as a substitute for the screen surface.
An optical design evaluation tool was used for evaluation on the CD camera and further on the projected screen surface. As an optical design evaluation tool, Litools (3rd edition) capable of non-sequential ray tracing analysis of Optical Reed Sachia Association of the United States was used, and the number of rays was set to about 200,000 (about 50 using a 1 GHz CPU. Minute calculation amount).
In order to reduce the calculation burden, ray tracing is performed only for a plurality of pixels in a specific area, and the light intensity distribution in a wide area on the screen surface is calculated by convolution with a separate calculation tool. ,evaluated. As the high pressure mercury lamp, the value of a DC discharge lamp of 150 W class manufactured by USHIO INC. Was used. The illumination angle is 5x8 fly-eye lens
It was designed and manufactured so that the illumination angle in the vertical direction was 7 degrees. In addition, the projection lens has an aperture corresponding to that of a high resolution of F2.4.

Table 2 shows Example 5 and Example 6 which are the evaluation values of pixel reduction in the configuration of FIG. Example 5 is
The buried layer 2 has a refractive index n = 1.83 and r = 150 μm. In Example 6, the buried layer 2 has a refractive index n = 1.
83, r = 190 microns. The pixel pitch is 14 microns.

[0080]

[Table 2]

Table 3 shows Comparative Example 1 and Table 4 shows Comparative Example 2 using the microlenses. However, the refractive index is the refractive index of a member having a convex shape, and the member having a concave shape is a fluorine-based photocurable adhesive, and the refractive index is n =
The thickness t is 1.4, which is the distance between the convex portion of the convex member and the liquid crystal layer, and includes the average thickness of 4 μm of the fluorine-based photocurable adhesive. The thickness t tends to become non-uniform depending on the thickness of the intermediate substrate, and when priority is given to in-plane uniformity, it is preferably at least 20 microns or more. The pixel pitch is 14 microns.

[0082]

[Table 3]

[0083]

[Table 4]

As can be seen by comparing Examples 5 and 6 and Comparative Examples 1 and 2, CT is better when the reflecting mirror is used.
It can be seen that at least two or more evaluation values of F, η, and α can be simultaneously improved, and the reduction of the remaining evaluation values can be minimized.

FIG. 8 shows the case where the refractive index of the buried layer is changed when the curvature r is fixed to 100 μm.
Example 7 which is an evaluation value of pixel reduction in the case of is shown. Figure 8
As shown in, the larger the refractive index of the buried layer is, the more the light utilization efficiency is 90% or more and the loss is 1/10 or less when the refractive index is 1.6 or more (n> = 1.6). The light utilization efficiency is very high. Further, if it is 1.7 or more, it is more preferable because the light utilization efficiency is substantially 97% or more. Further, as the refractive index becomes higher, the reduction ratio does not substantially change, but the light utilization efficiency decreases, and if the refractive index is 2.2 or less, various transparent dielectric materials have P
Can be formed by CVD, EB evaporation, sputtering, etc., and
Since these materials having a refractive index of 2.2 or less are easily subjected to drain etching, it is particularly preferable that the refractive index is 1.7 or more and 2.2 or less.

As shown in Example 7, a refractive index of 1 is better than that of a usual transparent material such as SiO ₂ , BK7, acrylic polymer, CYTOP, 1737 glass (Corning Co.) having a refractive index of 1.4 or more and less than 1.6. A material of 0.6 or more is preferable because the focal length f (absolute value) of the concave mirror is given by f = r / (nd) by the curvature r, the diameter d, and the refractive index n, as described above. The spherical aberration on the axis of the concave mirror, off-axis astigmatism, coma and other aberrations can be greatly reduced, and the operation is similar, but the incident illumination angle is This is because refraction at the flattening layer portion reduces the incident angle according to Snell's law, and the reflected light that becomes a light beam due to vignetting in the projection lens becomes smaller.

FIGS. 9 and 10 show Example 8 which is an evaluation value of pixel reduction when the curvature of the concave mirror in the configuration of FIG. 1 is changed. In Example 8, the refractive index of the buried layer was n =
At 1.6, the pixel pitch is 14 microns. As shown in FIG. 9, the reduction ratio is preferably such that the radius of curvature is larger than 30 microns and smaller than 250 microns, and more preferably 50 microns or more and 200 microns or less. Also, as shown in FIG. 10, the CTF changes abruptly.
Similarly, it is preferred that the radius of curvature be greater than 30 microns and less than 250 microns, more preferably 5
It is 0 micron or more and 200 micron or less. At this time,
The reduction ratio is 40% or more and 50% or less, neither reduction nor deterioration that deteriorates resolution, and since it is not a rectangular shape, more than 50% CTF can be secured. By using the optical axis shift element for the reduced pixel whose profile is modified, it is possible to realize an image display device that realizes a very high-quality image that can simultaneously realize image resolution and smoothness.

The pixel pitch in Example 8 is 14 microns, the radius of curvature can be normalized by the pixel pitch, and the number of displacement steps of the optical axis shift element is taken into consideration.
The range that achieves the extremely high resolution above is 2.2.
/(M/2)<r/d<17.9/(m/2) (where n is the refractive index of the embedded member and m is the number of modulation steps of the optical path modulator). Further, by taking this into consideration with the refractive index of the embedding layer of 1.6 or more, when the F value of the concave mirror surface is taken as the Fr value, 1.1 / (m / 2) <n ×
Fr <8.9 / (m / 2) (where n is the refractive index of the embedding member, m is the number of modulation steps of the optical path modulator) is a preferable range, and further, as an F value that is an illumination angle of 7 degrees. Considering 4 of No. 4, a more preferable range is 0.27 / (m / 2) <n ×, where F value of the illumination diameter is Fi value.
(Fr / Fi) <2.2 / (m / 2) (where n is the refractive index of the embedded member and m is the number of modulation steps of the optical path modulator).

FIG. 11 shows a ninth embodiment of the present invention, which is an example of the structure when the microlens and the mirror surface are integrated. In FIG. 11, 51 is a back plane having a top surface reflective electrode, 52 is a microlens, 53 is a flattening layer,
54 is a liquid crystal layer, and 55 is a counter substrate. Although not shown, ITO electrodes, contact holes and the like sandwiching the liquid crystal layer are formed as in FIG. At this time, since the reflection electrode and the microlens are integrated and arranged on the side opposite to the light source side with respect to the liquid crystal layer, the pixel profile can be deformed almost in the same manner as in FIG. Since it can be configured with a plane, it is easier to manufacture,
The yield can be improved and the cost can be reduced. The shape of the microlens can also act twice at the same location at the same time, so the curvature can be small, so the process is simple and the aberration is small. In addition to embedding the convex microlenses having a high refractive index with a material having a low refractive index to flatten the surface, a concave microlens having a low refractive index may be embedded with a material having a high refractive index.

FIG. 12 shows a tenth embodiment of the present invention which is another structural example in the case where the microlens and the mirror surface are integrated. In FIG. 12, 51 is a back plane having a top surface reflective electrode, 61 is a microlens lower layer, 62 is a microlens, 53 is a flattening layer, 54 is a liquid crystal layer, and 55 is
Is a counter substrate. Although not shown, ITO electrodes, contact holes and the like sandwiching the liquid crystal layer are formed as in FIG. At this time, the microlens is separated by the concave material and the lower layer 61. However, as an optical function, the microlens is located on the opposite side of the liquid crystal layer, so that the reflective electrode and the microlens are integrated as in FIG. It is the same as when it became. In this case, since the number of surfaces of the lens can be increased, the aberration of the lens can be further reduced, and the pixel profile can be controlled more, so that high-resolution image display can be performed. Also, by reducing the thickness of the lens,
It is also possible to reduce the absolute value of the variation in the thickness of the flattening layer during polishing caused by the stress corresponding to the uneven structure, and to provide an image display device with a more uniform gap, high contrast, and little in-plane variation. be able to.

FIG. 13 shows an eleventh embodiment of the present invention, which is an example of the structure when the micro prism and the mirror surface are integrated. In FIG. 13, reference numeral 51 is a back plane having an upper surface reflection electrode, 71 is a microlens, 53 is a flattening layer, 54 is a liquid crystal layer, and 55 is a counter substrate. Although not shown, ITO electrodes, contact holes and the like sandwiching the liquid crystal layer are formed as in FIG. At this time, similarly to FIG. 11, the reflection electrode and the microphone prism are integrated and are arranged on the side opposite to the light source side with respect to the liquid crystal layer, so that the pixel profile can be deformed substantially in the same manner as in FIG. At the same time, since the reflecting mirror and the prism can be configured by a flat surface, the manufacturing becomes easier, the yield is improved, and the cost can be reduced.

FIG. 14 shows a twelfth embodiment of the present invention, which is a structural example in which the modulation layer and the concave mirror surface are integrated. In FIG. 14, 81 is a backplane having an SRAM, 82 is a hinge pillar, 83a and 83b are concave mirror movable parts, and 84a and 84b are flattening layers for concave mirrors. 83
Reference numerals a and 83b are modulation layers which are manufactured by the MEMS technique and perform light modulation by deflection control. In the two states of 83a and 84a and 83b and 84b, reflected light of 0 value and 1 value is obtained. It is a reflective element that performs digital modulation. At this time, by forming a concave mirror structure in the portion which becomes the movable mirror, the pixel profile can be deformed almost in the same manner as in FIG. 1 or FIG. 11, and at the same time, it is not possible with the conventional microlens counter substrate. Moreover, since the pixel reduction in the deflection type light modulation element can be realized, the high contrast of the deflection type light modulation element can be realized and at the same time,
It is possible to solve the restriction on the pixel pitch, which is limited by the MEMS structure, by shifting the optical axis, and to realize a high-resolution image display device. Further, the flattening layer is effective because it can reduce the focal length of the concave mirror. In addition to the concave mirror structure, microlenses may be formed on a plane mirror.

FIG. 15 shows a thirteenth embodiment of the present invention, which is a structural example when a light shielding layer is used in the spatial light modulator.
In FIG. 15, reference numeral 51 is a back plane having an upper surface reflection electrode, 52 is a microlens, 53 is a flattening layer, 54
Is a liquid crystal layer, 55 is a counter substrate, and 91a, 91b, 9
Reference numerals 1c and 91d denote black matrix layers provided in a lattice pattern around the concave mirror. . Although not shown, ITO electrodes, contact holes and the like sandwiching the liquid crystal layer are formed as in FIG. At this time, the black matrix layer 9
1a to 91d can reduce the scattered light near the edge of the concave mirror, improve the contrast, and at the same time, can reduce the pixel size by masking the portion of the concave mirror having large aberrations, thereby achieving higher resolution. An image display device can be realized.

The reflection type light valve of FIG. 1 is not limited to the above-mentioned image display device, and may be used as a space type optical exchange switch for optical communication, a flat type light receiving element, The optical information processing circuit device may be configured by combining an arithmetic circuit, a planar light emitting element, a microlens multistage array, and the like.

[0095]

According to the present invention, when realizing a high resolution image display device using an optical axis shift element and a reflection type light valve, it is necessary in a conventional high resolution image display apparatus using an optical axis shift element. The high-precision alignment between the substrate having the driving circuit and the reflecting surface and the counter substrate having the microlens that deforms the pixel profile is performed.
An optical element that eliminates the microlens from the counter substrate having the microlens and drives the circuit and the substrate having the reflecting surface to reflect the pixel profile and at the same time deforms the pixel profile is provided. With such a configuration, it is possible to provide an image display device that is less expensive and more reliable, and that can reduce in-plane nonuniformity. Further, instead of causing the pixel profile modifying element consisting of a conventional microlens to act in the irradiation light path before transmitting the switching layer, the pixel profile modifying element acts in the irradiation light path after the first transmission of the switching layer. By doing so, it becomes possible to design an optical element in which the action on the liquid crystal layer in the outward path can be ignored, and this conventional microlens is operated in the path of the irradiation light before the transmission of the switching layer. Also, it is possible to provide an image display device having higher resolution and brighter visibility.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a reflective light valve according to the present invention.

FIG. 2 is a diagram for explaining an outline of the operation of the reflection-type light valve shown in FIG. 1, and is a diagram showing the operation of irradiation light and how an image of a pixel is formed by a reflecting concave mirror.

FIG. 3 is a diagram showing a relationship between a maximum angle θin at the time of incidence on a pixel and a maximum angle θout at the time of emission.

FIG. 4 is a diagram for explaining an operation of deforming a pixel profile emitted by a reflective light valve to increase the number of pixels.

FIG. 5 is a diagram for explaining an operation of time-divisionally projecting reduced pixels emitted from a reflective concave mirror by a reflective light valve.

FIG. 6 is an overall configuration diagram for explaining an example of a high definition projector to which the present invention is applied.

FIG. 7 is a diagram for explaining CTF.

FIG. 8 is a diagram showing evaluation values of pixel reduction when the refractive index of the embedded layer is changed.

FIG. 9 is a diagram showing a reduction ratio which is an evaluation value of pixel reduction when the curvature of the concave mirror is changed.

FIG. 10 is a diagram showing CTF which is an evaluation value of pixel reduction when the curvature of the concave mirror is changed.

FIG. 11 is a diagram showing an example in which a microlens and a mirror surface are integrated.

FIG. 12 is a diagram showing another embodiment in which the microlens and the mirror surface are integrated.

FIG. 13 is a diagram showing another embodiment in which the micro prism and the mirror surface are integrated.

FIG. 14 is a diagram showing an example in which the modulation layer and the concave mirror surface are integrated.

FIG. 15 is a diagram showing an example of the present invention as a configuration example when a light shielding layer is used for the spatial light modulator.

FIG. 16 is a diagram for explaining an example of a display device described in Japanese Patent Laid-Open No. 9-54554.

17 is a diagram showing a luminance state when the display device shown in FIG. 16 is not used.

FIG. 18 is a diagram showing a luminance state when the display device shown in FIG. 16 is used.

FIG. 19 is a diagram showing an example of a display device described in Japanese Patent Laid-Open No. 11-258585.

FIG. 20 is a diagram showing an example of a display device described in Japanese Patent Laid-Open No. 9-90310.

FIG. 21 is a cross-sectional configuration diagram for explaining an example of a reflective liquid crystal device described in Japanese Patent Laid-Open No. 09-90310.

[Explanation of symbols]

1 ... Reflective concave structure, 2 ... Buried layer, 3 ... Planarization layer, 4
... Liquid crystal layer, 5 ... Counter substrate, 6 ... Reflective electrode, 7, 8 ... Transparent electrode, 9 ... Through hole filling member, 10 ... Incident light flux, 1
DESCRIPTION OF SYMBOLS 1 ... Around a focal point, 12 ... Reduction pixel, 21 ... Spatial light modulation element, 22, 23 ... Piezo element, 24 ... Jig, 31 ... White light source, 32 ... Uniformization optical element, 33 ... Color separation device, 34
... Reflecting liquid crystal light valve, 35 ... Polarizing beam splitter, 36 ... Projection lens, 37 ... Screen, 41 ... Pixel, 51 ... Backplane, 52 ... Microlens, 5
3 ... Flattening layer, 54 ... Liquid crystal layer, 55 ... Counter substrate, 61 ...
Micro lens lower layer, 62 ... Micro lens, 71 ...
Micro lens, 81 ... Back plane, 82 ... Hiji pillar, 83a, 83b ... Concave mirror movable part, 84a, 84
b ... Flattening layer of concave mirror, 91a, 91b, 91c, 91
d ... Black matrix layer.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G02F 1/13357 G02F 1/13357 (72) Inventor Ikuo Kato 1-3-6 Nakamagome, Ota-ku, Tokyo In stock company Ricoh (72) Inventor Kenji Namie 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh stock company (72) Inventor Kenji Kameyama 1-3-6 Nakamagome, Tokyo Ota-ku Tokyo (72) Inventor Yasuyuki Takiguchi 1-3-6 Nakamagome, Ota-ku, Tokyo F-term in Ricoh Co., Ltd. (reference) 2H041 AA16 AB14 AC06 AZ01 AZ05 AZ08 2H079 AA02 AA12 BA01 CA02 DA08 EB01 GA05 KA01 KA14 2H088 EA13 EA16 FA16 EA16 FA18 GA02 HA20 HA24 HA28 MA06 MA20 2H091 FA10X FA17Y FA26X FA26Z FA41Z FA50X FA50Z FD02 LA18 LA30 MA07

Claims (19)

[Claims] 1. A light source that emits light, an irradiation optical element that shapes the light from the light source to be irradiation light, and a device that optically modulates the incident irradiation light and reflects and emits the irradiation light. A plurality of light modulation elements arranged on the same plane,
In a reflective spatial light modulator having an optical path modulator that spatially coordinates the optical paths of the outgoing light emitted from the plurality of optical modulators, the optical modulator emits irradiation light for each optical modulator. A reflection-type spatial light modulator comprising a reflection-type light flux profile deforming element that reflects and deforms a light flux profile of emitted light emitted by the reflection. 2. The reflection type spatial light modulator according to claim 1, wherein the reflection type light flux profile modifying element is an optical element having a concave mirror surface. 3. The reflection-type spatial light modulator according to claim 1, wherein the reflection-type luminous flux profile deformation element is an optical element having a concave mirror surface having a curved surface. 4. An embedding member that is a transparent member having a refractive index n of 1.6 or more and has a shape to be embedded in the mirror surface on the entrance / exit side of the concave mirror surface of the reflection type light flux profile modifying element. The reflective spatial light modulator according to claim 1, 2 or 3. 5. When the diameter of the concave mirror surface having the curved surface of the reflected light beam profile modifying element is d and the average curvature of the concave mirror surface is r, 2.2 / (m /
2) <r / d <17.9 / (m / 2) (where m is the number of modulation steps of the optical path modulator), The reflective space according to any one of claims 1 to 4. Light modulator. 6. When the F number of the concave mirror surface having the curved surface of the reflected light beam profile deforming element is taken as the Fr number, 1.1 / (m / 2) <n × Fr <8.9 / ( m / 2)
(Where n is the refractive index of the embedded member and m is the number of modulation steps of the optical path modulator).
6. The reflective spatial light modulator according to any one of 1 to 5. 7. When the F number of the concave mirror surface having the curved surface of the reflected light beam profile deformation element is Fr value and the F number of the irradiation light incident on the spatial light modulation element is Fi value, 0.27 / (m / 2) <n × (Fr / F
7. i) <2.2 / (m / 2) (where n is the refractive index of the embedding member, and m is the number of modulation steps of the optical path modulation element). Reflective spatial light modulator. 8. The reflection-type spatial light modulator according to claim 1, wherein the reflection-type luminous flux profile deformation element has an optical element in which a mirror surface and a microlens are integrated. . 9. The reflective spatial light modulator according to claim 8, wherein the microlens of the reflective light flux profile modifying element is a microlens having a curved surface. 10. The reflective spatial light modulator according to claim 8, wherein the microlenses of the reflective light flux profile modifying element include microlenses having a refractive index distribution member. 11. The reflection-type spatial light modulator according to claim 1, wherein the reflection-type luminous flux profile deformation element is an optical element in which a mirror surface and a microprism are integrated. . 12. The microlens or the microprism of the reflection type light flux profile modifying element,
The reflective spatial light modulator according to claim 4 or 9, further comprising a diffraction grating. 13. The light modulation element has a light modulation layer that modulates light by a change in transmittance or a change in deflection angle, and the reflection type light flux is on the side opposite to the incident direction of irradiation light with respect to the light modulation layer. The reflective spatial light modulator according to claim 1, further comprising a profile modifying element. 14. The reflective spatial light modulator according to claim 13, further comprising a flattening layer between the reflective light flux profile modifying element and the light modulation layer. 15. The reflective spatial light modulator according to claim 14, further comprising a conductive layer between the flattening layer and the light modulating layer of the reflective light flux profile modifying element. 16. The light modulation element has a light modulation layer that modulates light by a change in transmittance or a change in deflection angle, and the reflection type light flux profile modification element is integrated with the light modulation layer. The reflective spatial light modulator according to any one of claims 1 to 12, which is characterized in that. 17. The reflective spatial light modulator according to claim 1, wherein the light modulation element has a light shielding layer having an opening. 18. The full width at half maximum of the luminous flux profile of the emitted light emitted from the light modulation element is smaller than the original pitch of the light modulation element, and a position different from the position of the light modulation layer of the light modulation element is output. The reflective spatial light modulator according to any one of claims 1 to 17, further comprising an imaging lens that forms an image of emitted light. 19. The position at which the full width at half maximum of the luminous flux profile of the emitted light emitted from the light modulation element is smaller than the original pitch of the light modulation element and is different from the position of the light modulation layer of the light modulation element. The reflective spatial light modulator according to any one of claims 1 to 17, further comprising a virtual image forming lens that forms a virtual image of incident light.