JP2002148530A - Optical switching element, spatial optical modulator and image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical switching element having a high response speed and high contrast, and to provide a spatial optical modulator and an image display device applying the optical switching element. SOLUTION: The optical switching element (1) is provided with a reflection face capable of switching reflected light to parallel light and light to be focused and a light transmissible member having a part for interrupting the progress of light in the vicinity of the focus of the light to be focused. The spatial light modulator (2) is characterized by arraying plural optical switching elements (1) in one-dimensional or two-dimensional array state. The image display device (3) is provided with the modulator (2), a reflection face to be rotated around an axis parallel with the aligning direction of the arrayed optical switching elements (1), a driving mechanism of the reflection face, a means for making an optical beam incident on the modulator (2), and a means for projecting an image formed by the modulator (2) to a screen to display an image.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical switching element which can operate individually, a spatial light modulator which can transmit information spatially by using a plurality of the switching elements, and an image display device.

[0002]

2. Description of the Related Art There are the following three types of conventionally known technologies relating to an optical switching element using a mirror. (B) A mirror that bends light by bending or tilting a mirror attached with a cantilever or hinge. (B) A film light valve that focuses light by transforming a flat thin film into a spherical mirror. (C) A grating light valve that diffracts light by forming a periodic pattern. A disadvantage of the type (a) is a slow response time on the order of 10 μs. This is because the natural frequency of the cantilever is low and a large bending is required.
A disadvantage of the type (b) is that it is difficult to form a cavity under the thin film by micro-machining because the thin film is supported around the entire periphery, and it is difficult to machine. A disadvantage of the type (c) is that the optical efficiency is poor.

A mechanism (see FIG. 1) disclosed in Japanese Patent Application Laid-Open No. 2000-2842 is known as a light valve belonging to the type (b) and having a short response time and high efficiency. The configuration and function of FIG. 1 will be briefly described. When the reflected light from the metal coating 2 on the movable ribbon 1 is parallel light as shown in FIG. When the ribbon 1 bends and the reflected light is focused, the reflected light can pass through the slit 9 located near the focal point, thereby adjusting the light beam of one pixel. However, in the above device, even if the reflected light is parallel light, a part of the light beam passes through the slit, so it is impossible to create a state in which the transmitted light is completely blocked, and there is a limit to high contrast There is a problem that there is.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an optical switching element having a high response speed and a high contrast, a spatial light modulator and an image display apparatus using the same, which have solved the above-mentioned problems. .

[0005]

Means for Solving the Problems The above problems are as follows:
The invention 12) (hereinafter referred to as Inventions 1 to 12) is solved. 1) A reflecting surface capable of switching reflected light into a parallel light beam and a focusing light beam, and a light transmitting member having a portion near the focal point of the focusing light beam that hinders the propagation of the light beam. An optical switching element characterized by the above-mentioned. 2) The optical switching element according to 1), wherein the portion that hinders the propagation of the light beam is made of a light-absorbing material that absorbs light reflected on the reflection surface. 3) The optical switching element according to 1), wherein the portion that hinders the propagation of the light beam is made of a light reflecting material that reflects light reflected on the reflection surface. 4) The area ratio (S2) of the area S2 of the portion obstructing the progress of light to the area S1 of the light transmitting member through which the parallel light passes.
2 / S1) is set to 1/10 or less in the case of the double-supported beam type, and 1/100 or less in the case of the all-around holding type. The optical switching element as described in the above. 5) A spatial light modulator, wherein the optical switching elements according to any one of 1) to 4) are arranged in a one-dimensional array. 6) Spatial light modulation in which a plane on which the optical switching elements according to any one of 1) to 4) are arranged in a one-dimensional array is rotatably provided about an axis parallel to the alignment direction of the optical switching elements. A spatial light modulator, comprising: a modulator; and a drive mechanism for rotating the spatial light modulator. 7) A spatial light modulator, wherein the optical switching elements according to any one of 1) to 4) are arranged in a two-dimensional array. 8) The spatial light modulator according to 5), a reflecting surface rotatably provided about an axis parallel to the alignment direction of the arranged optical switching elements, and a driving mechanism thereof, and the spatial light modulator. An image display device comprising: means for making a light beam incident; and means for projecting and displaying an image formed by the spatial light modulator on a screen. 9) A spatial light modulator according to 6), means for causing a light beam to be incident on the spatial light modulator, and means for projecting and displaying an image formed by the spatial light modulator on a screen. An image display device characterized by the above-mentioned. 10) A spatial light modulator according to 7), a means for causing a light beam to be incident on the spatial light modulator, and a means for projecting and displaying an image formed by the spatial light modulator on a screen. Characteristic image display device. 11) The image display device according to any one of 8) to 10), further comprising a function of displaying an image of each color in a time-division manner with incident light of a plurality of wavelengths such as red, green, and blue. Image display device. 12) The full-color image display device according to any one of 8) to 10), further comprising a function of simultaneously projecting images of each color by a plurality of spatial light modulators.

The switching element of the present invention has a reflecting surface capable of switching reflected light into a parallel light beam and a focusing light beam, and a light having a portion near the focal point of the focusing light beam that hinders the propagation of the light beam. A transparent member. The reflected light transmits through the light-transmitting member in the case of a parallel light beam, but cannot pass through the light-transmitting member in the case of a focused light beam because it is blocked by a portion that hinders the progress of the light beam. By arranging the optical switching elements of the present invention in a one-dimensional or two-dimensional array, a spatial light modulator can be configured. The one-dimensionally arranged spatial light modulators can realize two-dimensional spatial light modulation by using a scanning mechanism that scans in a direction perpendicular to the arrangement direction of the optical switching elements. Further, if the one-dimensionally arranged spatial light modulators themselves are scanned by the scanning mechanism, a small and inexpensive spatial light modulator can be configured. In the above spatial light modulator, an image display device can be configured by combining a means for making a light beam incident thereon and a means for projecting a formed image on a screen.

Hereinafter, the present invention will be described in detail while showing a specific configuration. FIG. 2 shows an embodiment of the present invention. The reflection surface 101 has a function of reflecting incident light, is separated from the silicon substrate 103 by the layer 102, and is supported on the silicon substrate. The material of the layer 102 may be metal or non-metal. The lower part of the reflecting surface is hollow. The material of the reflective surface is
Silicon, aluminum, silicon nitride, or the like can be used, but it is desirable to provide a reflective film on the surface in order to increase the reflectance. The advantage of silicon nitride is that it has a higher response frequency due to its higher resonance frequency. Furthermore, silicon nitride has a longer life because it is less likely to fatigue than aluminum. In addition, the reflective surface also functions as an electrode if formed of a metal coating of aluminum, silver, or the like. It is possible to provide the reflective surface with wavelength selectivity by coating with a dielectric multilayer film or the like, but in that case, it is necessary to provide an electrode for driving. The second electrode 104 is deposited below the air chamber 105. When the reflective surface has the function of an electrode, the two electrodes 101 and 104 form a capacitor, so that when a voltage is applied between the two electrodes, the reflective surface bends due to electrostatic attraction. The reflecting surface when the electrode is applied is a cylindrical side surface in the case of a doubly supported beam, and a substantially spherical surface or a paraboloid of revolution surface when it is held all around. However, since it is a small deflection with respect to the size of the reflecting surface,
Even if the shape cannot be clearly defined functionally (mathematically), there is no particular problem.

The incident light beam 106 is reflected by (the coating of) the reflecting surface. The behavior of the reflected light according to the type of the incident light will be described. First, when the incident light is a parallel light, when the device is not active as shown in FIG. As a result, the reflected light reaches the light transmissive member 107 as parallel rays and is transmitted therethrough (hereinafter, this is referred to as an ON state). However, a small amount of light reaching the light blocking portion 108 is prevented from traveling. On the other hand, FIG.
When the device is activated, as shown in (b), the reflecting surface is deflected to become a spherical surface, a paraboloid of revolution surface or a cylindrical side surface, so that the reflected light is focused, and a portion 108 that hinders the propagation of light near the focal point. Therefore, the light cannot pass through the light transmitting member 107 (hereinafter, this is called an OFF state). Secondly, in the case of a non-parallel ray (convergent ray) in which the incident light is focused, the reflected light can be turned into a parallel ray by making the reflection surface a convex spherical surface, a paraboloid of revolution surface or a cylindrical side surface, so that ON. 3 (a). Since the reflected light can be focused by making the reflecting surface flat, the OFF state [FIG.
(B)]. Third, in the case of non-parallel rays (divergent rays) in which the incident light is diffused, the reflected light can be turned into parallel rays by making the reflecting surface a downwardly convex spherical surface, parabolic rotating body surface or cylindrical side surface, so that the reflected light can be turned on. FIG. 4A shows that the reflected light can be focused by further increasing the curvature of the reflecting surface, so that the OFF state is obtained as shown in FIG. 4B. In this way, the high-speed optical switching element 109 can be configured by switching the shape of the reflecting surface for any type of incident light.

The light transmitting member is made of glass or plastic having high light transmitting property. The portion that inhibits light transmission may be any as long as it absorbs or reflects the reflected light and prevents the reflected light from passing through the light transmitting member. Examples of the light-absorbing material that can constitute the inhibition portion include carbon black, inorganic pigments such as iron oxide and chromium oxide, and dyes such as direct black and acid black. Also, a plurality of dyes or pigments having different absorption wavelength regions may be mixed to have absorption in a wide wavelength range. As the light reflecting material that can constitute the obstructing portion, a metal having excellent visible light reflecting characteristics such as aluminum and silver is preferable, and the reflecting surface is oriented so that the reflected light does not enter the reflecting surface of another element. Install.

The main advantages of this optical switching element are:
This means that a sufficiently efficient operation can be performed even with a very small deflection of μm or less. In order to reduce the size of the entire apparatus, it is necessary to reduce the size of each element. Therefore, the practical size is at least about 10 μm × 10 μm. Increasing the area of the portion that hinders the progress of light can surely hinder the transmission of light in the OFF state, but reduces the amount of light transmission in the ON state, resulting in lower contrast. Therefore,
It is desirable that the area of the portion that hinders the progress of light be as small as possible within a range where the focused reflected light can be hindered without leakage. Specifically, it is optimal to make it as small as the diffraction limit of the light beam so as to match the position of the focal point. Therefore, it is practical to set the width to about 1 μm, and the area ratio (S2 / S1) of the area S2 of the portion obstructing the propagation of light to the area S1 of the light transmitting member at that time is (S2 / S1) In this case, it is preferably about 1/10 or less, and in the case of the full circumference holding type, about 1/100 or less.

The possibility of achieving high contrast will be further described. In the conventional method disclosed in Japanese Patent Application Laid-Open No. 2000-2842, the area ratio between the light-shielding plate and the slit is assumed to be the same as that described above, and the ON-state is considered. Although the amount of transmitted light is 100% with respect to the incident light, about 10% of the reflected light passes through the slit even in the OFF state, so that the ON / OFF transmission amount ratio is only about 100/10 = 10 times. However, there is a limit in increasing the contrast. On the other hand, in the method of the present invention, the amount of transmitted light in the ON state is 80 to 90% for the double-supported beam and 96 to 99% for the entire circumference, but is almost 0% in the OFF state. The transmitted light amount ratio in the OFF state is 90/0 = ∞
Doubling and there is almost no limit. This is the greatest advantage of the present invention.

FIG. 5 shows a spatial light modulator according to the present invention. By arranging the optical switching elements 109 in a one-dimensional array, a one-dimensional spatial light modulator 110 can be formed. FIGS. 5A and 5B show a doubly supported beam type and an all-around holding type, respectively. The ON / OFF (spatial light modulation) of linear light can be performed by bending or returning the reflecting surface 101 of each switching element 109 arranged in an array. A scanning mechanism (device) that scans the spatial light modulator in a direction perpendicular to the direction in which the optical switching elements are arranged.
Or two-dimensional spatial light modulation can be performed by providing a mechanism for rotating the optical switching elements around the arrangement direction. That is, as shown in FIG. 6, the driving of the reflection surface 101 of the spatial light modulator 110 and the scanning mechanism (device) 114
Is controlled by an image signal, and the obtained two-dimensionally spatially modulated light beam is projected on a screen, whereby an image display device can be formed.

Further, as shown in FIG. 7, by providing a scanning mechanism in the one-dimensional spatial light modulator itself and performing scanning in a direction perpendicular to the arrangement of the optical switching elements, it is possible to provide a smaller image display device. In this case, the light transmissive member is also linked to the spatial light modulator, and is always at a position where the reflected light can be transmitted or hindered. FIGS. 6 and 7 show the case where the reflection surface is a doubly supported beam type. However, the image display device can be similarly formed by using a spatial light modulator using an optical switching element having a reflection surface having an all around circumference. Can be. Further, even when the incident light is not a parallel light beam, an image display device can be similarly formed. As the scanning mechanism, an existing method such as a galvano method using Lorentz force, a method using electrostatic force, or a method using electrostriction or magnetostriction can be used.

As shown in FIG. 8, a two-dimensional spatial light modulator can be formed by arranging the reflecting surfaces in a two-dimensional array. In this case, since two-dimensional spatial light modulation can be performed only by the spatial light modulator, an image display device can be formed without providing a scanning mechanism as shown in FIGS. In the image display apparatus using the one-dimensional array or two-dimensional array of spatial light modulators, images of each color are displayed in a time-division manner using incident light of a plurality of wavelengths such as red, green, and blue. Alternatively, a full-color image can be displayed by providing a plurality of spatial light modulators and projecting images of each color at the same time (field sequential method).

[0015]

EXAMPLES The present invention will be described below in more detail with reference to examples, but the present invention is not limited to these examples.

Example 1 A light-transmitting member made of polished quartz glass was prepared by sputtering carbon black on a part of one surface of the light-transmitting member in a streak shape having a width of 1 μm as a part for inhibiting light rays.
Further, the reflection surface of the spatial light modulator shown in FIG. 5A and its driving mechanism were manufactured as follows (see FIG. 9). First, a silicon oxide layer 151 was formed on the surface of a silicon substrate 150 by heat treatment, a silicon nitride layer 152 was formed thereon by low-pressure CVD (chemical vapor deposition), and a conductive layer 153 was formed thereon by vapor deposition. . The conductive layer material is desirably a high-conductivity high-melting-point metal or alloy such as tungsten, molybdenum, or tantalum. In this case, tungsten is used. Next, the sacrificial layer 15 is formed thereon by CVD.
4 was formed. The sacrificial layer is a layer that is selectively etched in a later step to form a movable space. As a material of the sacrificial layer, an impurity-added glass such as phosphorus silicate glass or boron phosphorus silicate glass is usually used. Here, phosphorus silicate glass is used. The thickness of the sacrificial layer needs to be such that the electrodes do not come into contact with each other when the reflecting surface formed in a later step is driven. Next, by patterning and etching with a photoresist material, a concave portion for forming a column portion of the doubly supported beam was formed such that the length (L) of the doubly supported beam became 10 μm. Note that the length in the depth direction of the paper of FIG. 9 is 5 mm.
Next, as shown in FIG. 10, an elastic material layer 155 constituting a doubly supported beam is formed. Since the elastic material layer has a role of a spring which bends downward due to the electrostatic force and returns quickly when the electrostatic force is released, the material used for the elastic material layer has such a spring force. Preferably, silicon nitride is used here and formed by a CVD method. Next, a silver layer 157 is formed by vapor deposition on the conductive layer 153 on the upper surface of the elastic material layer. This serves as both a reflective layer and a conductive layer, and forms a capacitor together with the conductive layer 153. Next, patterning and etching are performed with a photoresist so that the width (W) of each element of the doubly supported beam is 10 μm and the interval (g) of each doubly supported beam is 4 μm, thereby separating the doubly supported beam and forming the sacrificial layer 154. Removal was performed. Next, the conductive layer 153 is used as a common electrode, and an electrode is extracted from the electrode layer of each doubly supported beam. Lastly, the light transmissive member was placed at a position 13 μm from the spatial light modulator to produce a one-dimensional spatial light modulator. In the state where no signal is input to the electrodes, the spatial light modulator manufactured as described above has a flat reflecting surface as shown in FIG. When a voltage is applied between the conductive layer and the electrode layer of the selected doubly supported beam, the doubly supported beam is bent as shown in FIG. Because it is hindered, it cannot pass through the light transmitting member. In this embodiment, laser light (wavelength 670 nm) shaped by a lens so that the beam shape becomes 1 mm × 5 mm.
Was input from the entrance surface of the quartz prism, and the drive voltage was 5 V to selectively operate the drive mechanism having the double-supported beam structure, thereby performing high-speed spatial light modulation with good contrast.

Example 2 A one-dimensional spatial light modulator was produced in the same manner as in Example 1 except that aluminum was sputtered in a streak shape having a width of 1 μm as a light-inhibiting portion instead of carbon black in Example 1. Was prepared. The aluminum reflects the reflected light in the vicinity of its focal point, hinders the reflected light from passing through the light transmitting member, and can perform high-speed spatial light modulation with good contrast as in the first embodiment. Was.

Example 3 A portion of one side of a light-transmitting member made of a glass substrate, in which carbon black is sputtered in a dot-like manner at the position of the focal point of each optical switching element as a portion that blocks light rays. Was prepared. Further, the reflecting surface of the spatial light modulator shown in FIG. 5B and its driving mechanism were manufactured as follows. That is, as shown in FIG.
On the surface of No. 8, a circular groove having a diameter of 10 μm to be a gap 160 was formed, and a conductive layer 153 was formed on the bottom surface. Conductive layer 15
A drive signal is applied to No. 3 by a back wiring through a via hole (not shown). Next, the silicon substrate 1
After bonding 50 to the glass substrate 158 by anodic bonding,
The film was thinned by etching to form a diaphragm (also a reflection mirror) 159. Finally, a one-dimensional spatial light modulator was manufactured in combination with a light transmitting member. This spatial light modulator was able to perform high-speed spatial light modulation with good contrast under the same driving conditions as in Example 1.

Example 4 In the same manner as in Example 3 except that instead of carbon black in Example 3, aluminum was formed as a point that obstructs light rays in a dot-like manner at the focal position of each optical switching element. To produce a one-dimensional spatial light modulator.
The aluminum reflected the reflected light at its focal point, hindered the reflected light from passing through the light transmitting member, and performed high-speed spatial light modulation with good contrast as in Example 3. .

Example 5 A spatial light modulator was manufactured by combining the spatial light modulator of Example 1 with a scanning mechanism of the galvano system in the configuration shown in FIG. The scanning mechanism used had a scanning angle of 20 °. A white light source was used as the incident light, and the spatial light modulator and the scanning mechanism were driven by the image signal. As a result, a moving image could be displayed on the screen.

Embodiment 6 The image display apparatus having the structure shown in FIG. 7 was manufactured by assembling the spatial light modulator of Embodiment 1 with a scanning mechanism of a galvano system. Using laser light (wavelength 670 nm) as the incident light and driving the spatial light modulator and the scanning mechanism by an image signal, a moving image could be displayed on the screen.

[0022]

According to the present invention, an optical switching element having a high response speed and a high contrast can be provided. Invention 2
According to 3, an optical switching element having a good SN ratio can be provided. According to the fourth aspect, an optical switching element having a high contrast ratio can be provided. According to the fifth aspect, a spatial light modulator having a high response speed and a high contrast can be provided. According to the sixth aspect, it is possible to provide a small and inexpensive spatial light modulator having a high response speed, a high contrast, and a small size.
According to the seventh aspect, a spatial light modulator having a high response speed and a high contrast can be provided. According to the inventions 8 to 10,
An image display device capable of performing high-definition display on a large screen can be provided. According to the present invention, it is possible to provide a full-color image display device capable of performing high-definition display on a large screen.

[Brief description of the drawings]

FIG. 1 is a view showing a high-speed deformable mirror light valve described in JP-A-2000-2842. (A) Sectional view when not active. (B) Sectional view in the active state.

FIG. 2 is a diagram showing an optical switching element of the present invention. (A) Sectional drawing when incident light is parallel light and the element is not active (ON state). (B) When the incident light is parallel light and the device is in the active state (O
Sectional view of FF state).

FIG. 3 is a diagram showing an optical switching element of the present invention. (A) Sectional drawing when incident light is convergent light and the element is not active (ON state). (B) When the incident light is convergent light and the device is active (O
Sectional view of FF state).

FIG. 4 is a diagram showing an optical switching element of the present invention. (A) Sectional view when incident light is divergent light and the element is not active (ON state). (B) When the incident light is divergent light and the element is active (O
Sectional view of FF state).

FIG. 5 is a diagram showing a spatial light modulator in which the optical switching elements of the present invention are arranged in a one-dimensional array. (A) The figure which shows a doubly supported beam type. (B) The figure which shows the full circumference holding type.

FIG. 6 is a diagram showing an image display device using the spatial light modulator of the present invention.

FIG. 7 is a diagram showing an image display device having a configuration different from that of FIG. 6 using the spatial light modulator of the present invention.

FIG. 8 is a diagram showing a spatial light modulator in which the optical switching elements of the present invention are arranged in a two-dimensional array.

FIG. 9 is a diagram for explaining an operation procedure of the spatial light modulator according to the first embodiment.

FIG. 10 is a view for explaining the operation procedure of the spatial light modulator according to the first embodiment (continuation of FIG. 9).

FIG. 11 is a diagram illustrating a configuration of a spatial light modulator according to a third embodiment.

FIG. 12 is a diagram showing a state of the spatial light modulator of the present invention at rest.

FIG. 13 is a diagram showing a state when a voltage is applied to the spatial light modulator of the present invention.

[Explanation of symbols]

 Reference Signs List 1 ribbon 2 metal coating 3 layer 4 silicon substrate 5 second electrode 6 air chamber 7 light beam 8 stopper 9 slit (wire diameter) 10 voltage 101 reflecting surface 102 layer 103 silicon substrate 104 second electrode 105 air chamber 106 light beam 107 light transmittance Member 108 Blocking part 109 Optical switching element 110 Spatial light modulator 111 Light source 112 Collimating lens 113 Projection lens 114 Scanning mechanism 115 Screen 150 Silicon substrate 151 Silicon oxide layer 152 Silicon nitride layer 153 Conductive layer 154 Sacrificial layer 155 Elastic material layer 157 Reflective layer 158 Glass substrate 159 Diaphragm part 160 Void part g Interval of doubly supported beam L Length of doubly supported beam W Width of doubly supported element

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hideki Tomino 1-3-6 Nakamagome, Ota-ku, Tokyo F-term in Ricoh Co., Ltd. (Reference) 2H041 AA05 AB14 AC06 AZ08 2H045 AB00 BA02 DA31 5C058 AA18 AB07 EA02 EA13 EA13 EA54

Claims (12)

[Claims] 1. A reflecting surface capable of switching reflected light into a parallel light beam and a focusing light beam, and a light transmitting member having a portion near the focal point of the focusing light beam that inhibits the propagation of the light beam. An optical switching element, comprising: 2. The optical switching element according to claim 1, wherein the portion that hinders the propagation of the light beam is made of a light absorbing material that absorbs the light reflected on the reflection surface. 3. The optical switching element according to claim 1, wherein the portion that hinders the propagation of the light beam is made of a light reflecting material that reflects the light reflected on the reflecting surface. 4. The area ratio (S2 / S1) of the area S2 of the portion that inhibits light propagation to the area S1 of the light transmissive member through which the parallel light passes is 1/2 in the case of the doubly supported beam type.
The optical switching element according to any one of claims 1 to 3, wherein the optical switching element is set to 10 or less, and to 1/100 or less in the case of an all around holding type. 5. A spatial light modulator, wherein the optical switching elements according to claim 1 are arranged in a one-dimensional array. 6. A plane in which the optical switching elements according to claim 1 are arranged in a one-dimensional array so as to be rotatable around an axis parallel to an alignment direction of the optical switching elements. A spatial light modulator, comprising: a spatial light modulator; and a drive mechanism for rotating and driving the spatial light modulator. 7. A spatial light modulator, wherein the optical switching elements according to claim 1 are arranged in a two-dimensional array. 8. A spatial light modulator according to claim 5, a reflecting surface rotatably provided around an axis parallel to an alignment direction of the arranged optical switching elements, a driving mechanism therefor, and the spatial light. An image display device comprising: means for causing a light beam to enter a modulator; and means for projecting and displaying an image formed by the spatial light modulator on a screen. 9. The spatial light modulator according to claim 6, a means for causing a light beam to enter the spatial light modulator, and a means for projecting and displaying an image formed by the spatial light modulator on a screen. An image display device comprising: 10. A spatial light modulator according to claim 7, further comprising: means for causing a light beam to be incident on said spatial light modulator; and means for projecting and displaying an image formed by said spatial light modulator on a screen. An image display device, characterized in that: 11. The image display device according to claim 8, further comprising a function of displaying an image of each color in a time-division manner with incident light of a plurality of wavelengths such as red, green, and blue. Full-color image display device. 12. The full-color image display device according to claim 8, further comprising a function of simultaneously projecting an image of each color by a plurality of spatial light modulators.