JP2007171613A - Optical device, variable filter device, projection display device and shutter device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To attain miniaturization and high speed operation of an optical device, a variable filter device, a projection display device and a shutter device in comparison with means using macro mechanical mechanism and to raise use efficiency of light. <P>SOLUTION: The optical device 2 has a plurality of elements 10 two-dimensionally arranged on a substrate 11. Each element 10 has a rotating plate 12 whose posture regarding an angle is variable to the substrate 11 and an optical filter 13 provided on the rotating plate 12. Parts except the optical filter 13 among the elements 10 constitute one microactuator. The optical filter 13 is of a transmission type or reflective type having wavelength selection properties. The wavelength selection properties of the optical filter 13 vary depending on an incidence angle of incident light to the optical filter 13. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optical device, a variable filter device using the optical device, a projection display device using the variable filter device, and a shutter device using the optical device.

  At present, optical devices using liquid crystals are widely used in place of optical means using a macro mechanical mechanism in order to reduce the size and increase the operation speed.

  For example, a liquid crystal shutter is used in place of a mechanical shutter as a shutter that turns on and off the passage of light.

Further, for example, Patent Document 1 below discloses that, in a projection display device (projector), a variable filter device using liquid crystal is used instead of a variable filter device using a macro mechanical mechanism. The former variable filter device is disclosed in FIG. 4 of Patent Document 1, and includes a disk-type color filter in which red, green, and blue color filters are sequentially arranged in a fan shape, and a motor that rotates the disk-type color filter. It is configured. The latter variable filter device is disclosed in FIG. 2 of Patent Document 1, and is a liquid crystal shutter provided with red, green, and blue color filters (referred to as “color shutter” in Patent Document 1). And a control unit that controls the liquid crystal shutter so that light of a color selected according to a switching signal of red, green, and blue selectively passes therethrough.
JP 7-168147 A

  As described above, the liquid crystal device and the shutter device and variable filter device using the liquid crystal device are very excellent in terms of miniaturization and high-speed operation compared to the optical means using the macro mechanical mechanism.

  However, in these devices and apparatuses, since liquid crystals are used, the light use efficiency is essentially reduced. That is, the liquid crystal removes one polarized light and uses the other polarized light that is transmitted or reflected, so that half of the light amount of the light source is wasted. For this reason, not only does it become dark light, but wasteful power consumption also occurs.

  The present invention has been made in view of such circumstances, and can achieve a reduction in size and speed of operation as compared with a means using a macro mechanical mechanism, and also enhances the light utilization efficiency. It is an object to provide an optical device and a variable filter device, a projection display device, and a shutter device using the optical device.

  In order to solve the above problems, an optical device according to a first aspect of the present invention includes: (i) a plurality of microactuators having a movable portion that can change an attitude with respect to an angle with respect to a substrate; A microactuator array in which the movable portion is arranged one-dimensionally or two-dimensionally on one surface side of the substrate; and (ii) a transmission type having wavelength selection characteristics provided in the movable portion of each microactuator. A reflection-type optical filter, wherein the wavelength selection characteristic changes according to an incident angle of incident light with respect to the optical filter.

  An optical device according to a second aspect of the present invention is the optical device according to the first aspect, wherein each of the optical filters of the optical device has a bandpass characteristic having one or more pass wavelength bands as the wavelength selection characteristic. is there.

  The optical device according to a third aspect of the present invention is the optical device according to the first or second aspect, wherein the optical filters of the optical device are substantially different from each other when incident angles of incident light with respect to the optical filter are the same. Have the same wavelength selection characteristics.

  An optical device according to a fourth aspect of the present invention is the optical device according to any one of the first to third aspects, wired so that a drive signal is commonly supplied to the plurality of microactuators. .

  The optical device according to a fifth aspect of the present invention is the optical device according to any one of the first to fourth aspects, wherein the movable part of at least one of the plurality of microactuators is attached to the substrate by a torsion hinge. On the other hand, it includes a rotating portion supported so as to be rotatable around a predetermined rotation axis.

  The optical device according to a sixth aspect of the present invention is the optical device according to the fifth aspect, wherein the at least one microactuator can apply a first driving force in one rotational direction to the rotating portion. A force applying unit, and a second driving force applying unit capable of applying a second driving force in the other rotation direction to the rotating unit.

  The optical device according to a seventh aspect of the present invention is the optical device according to the sixth aspect, wherein the rotating unit is rotated in the one rotation direction by the first driving force with respect to the at least one microactuator. The angle of the rotating part relative to the one surface of the substrate when held in contact with the first contacted part on the substrate side, and the rotating part rotates the other by the second driving force The angle of the rotating portion with respect to the one surface of the substrate when the rotating portion rotates in the direction and is held in contact with the second contacted portion on the substrate side is set to be different from each other. It is a thing.

  The optical device according to an eighth aspect of the present invention is the optical device according to any one of the first to fourth aspects, wherein the movable part of at least one of the plurality of microactuators has a cantilever structure. The movable portion is provided so as to generate a return force for returning to a predetermined posture, and the movable portion includes a drive force generating portion capable of generating a drive force against the return force.

  The optical device according to a ninth aspect of the present invention is the optical device according to the eighth aspect, wherein the driving force generator is a current path that is arranged in a magnetic field and generates a Lorentz force by energization.

  A variable filter device according to a tenth aspect of the present invention receives incident light, and transmits light in a part of the incident light that is variably selected in a predetermined wavelength region within the predetermined wavelength region. A variable filter device that selectively passes, comprising: an optical device according to any one of the first to ninth aspects; and a control unit that controls the optical device in accordance with a selection signal; Each of the optical filters receives each of the partial light beams of the incident light, and the control unit includes any of the light after the partial light beams of the incident light are transmitted or reflected by the optical filters of the optical device. However, the posture of the movable portion of each microactuator is controlled so that the light components have wavelength components corresponding to the selection signal and substantially the same wavelength components.

  The variable filter device according to an eleventh aspect of the present invention is the variable filter apparatus according to the tenth aspect, wherein the predetermined wavelength region is a visible region.

  In the tunable filter device according to a twelfth aspect of the present invention, in the tenth or eleventh aspect, the light in the predetermined wavelength region of the incident light is composed of light in a plurality of discrete wavelength bands, and the optical Each optical filter of the device has a bandpass characteristic having a plurality of discrete pass wavelength bands as the wavelength selection characteristic, and for each optical filter of the optical device, the plurality of pass wavelength bands of the optical filter Any one of the plurality of wavelength bands of the incident light overlaps any one of the plurality of wavelength bands of the incident light. The plurality of pass wavelength bands of the optical filter are set so as not to substantially overlap with the wavelength band.

  The variable filter device according to a thirteenth aspect of the present invention is the variable filter device according to the twelfth aspect, wherein the light of the plurality of discrete wavelength bands constituting the incident light is light of a red wavelength band, light of a green wavelength band. Light and light in the blue wavelength band.

  The variable filter device according to a fourteenth aspect of the present invention is the variable filter device according to the tenth or eleventh aspect, wherein the incident light has a continuous spectrum within the predetermined wavelength region, and the optical filters of the optical device. Has a band pass characteristic having a single pass wavelength band having a narrower bandwidth than the predetermined wavelength region as the wavelength selection characteristic, and for each optical filter of the optical device, the pass wavelength band of the optical filter is The pass wavelength band of the optical filter is set so as to overlap the predetermined wavelength region.

  In the variable filter device according to a fifteenth aspect of the present invention, in any one of the tenth to fourteenth aspects, each optical filter of the optical device is a transmissive optical filter, and the substrate is the incident light. Transparent to the light in the part of the wavelength range variably selected in the predetermined wavelength region, and part of the variable light in the predetermined wavelength region of the incident light. After the light in the wavelength band passes through the substrate, it enters the optical filter of the optical device, or the wavelength band of the variably selected part of the incident light in the predetermined wavelength region. The light passes through the substrate after passing through the optical filters.

  The variable filter device according to a sixteenth aspect of the present invention is the variable filter device according to the fifteenth aspect, wherein a part of the variably selected light in the predetermined wavelength region of the incident light is transmitted through the substrate. After that, a microlens that enters each optical filter of the optical device and collects a partial light flux of the incident light on the optical filter is formed on the incident light incident side of the substrate.

  A projection display device according to a seventeenth aspect of the present invention receives incident light including light in a red wavelength band, light in a green wavelength band, and light in a blue wavelength band, and receives light in the red wavelength band, A variable filter device that sequentially and selectively passes light in a green wavelength band and light in a blue wavelength band, and sequentially receives light in each color wavelength band from the variable filter device; And a projection optical system that projects the modulated light obtained by the spatial light modulation unit, wherein the variable filter device is used as the variable filter device. The variable filter device according to any one of 1 to 16 is used.

  A shutter device according to an eighteenth aspect of the present invention is configured to receive incident light and to pass light of at least a part of a wavelength band within a predetermined wavelength region of the incident light, and the incident light A shutter device capable of switching between a second state in which light within the predetermined wavelength region is not substantially passed, wherein the optical device according to any one of the first to ninth aspects and the switching device according to the switching signal A control unit that controls the optical device, wherein each optical filter of the optical device receives each partial light beam of the incident light, and the control unit displays the first state when the switching signal indicates the first state Each of the micro-beams so that each of the light beams after the partial light beams of the incident light are transmitted or reflected by the optical filters of the optical device become light in the at least some wavelength bands. Acti When the attitude of the movable part of the eta is controlled and the switching signal indicates the second state, the passing wavelength band of each optical filter of the optical device is substantially the same as any wavelength band of the incident light. The posture of the movable part of each microactuator is controlled so as not to overlap.

  A shutter device according to a nineteenth aspect of the present invention is the shutter device according to the eighteenth aspect, wherein the predetermined wavelength region is a visible region.

  The shutter device according to a twentieth aspect of the present invention is the shutter device according to the eighteenth or nineteenth aspect, wherein the light in the predetermined wavelength region of the incident light comprises light of a plurality of discrete wavelength bands, Each optical filter of the optical device has a bandpass characteristic having a plurality of discrete pass wavelength bands as the wavelength selection characteristic, and the incident light in the first state with respect to each optical filter of the optical device. The plurality of pass wavelength bands of the optical filter are set so that the light of the plurality of wavelength bands respectively overlaps the plurality of pass wavelength bands of the optical filter.

  The shutter device according to a twenty-first aspect of the present invention is the shutter device according to the twentieth aspect, wherein the light of the plurality of discrete wavelength bands constituting the incident light is light of a red wavelength band, light of a green wavelength band. And light in the blue wavelength band.

  The shutter device according to a twenty-second aspect of the present invention is the shutter device according to any one of the eighteenth to twenty-first aspects, wherein each of the optical filters of the optical device is a transmissive optical filter, and the substrate is configured to transmit the incident light. The transparent light is transparent to the light of the at least part of the wavelength band within the predetermined wavelength region, and the light of the at least part of the wavelength band of the incident light within the predetermined wavelength region is transmitted through the substrate. After the incident on each optical filter of the optical device, or after the light of the at least a part of the wavelength band in the predetermined wavelength region of the incident light is transmitted through the optical filter, the substrate It is transparent.

  The shutter device according to a twenty-third aspect of the present invention is the shutter device according to the twenty-second aspect, wherein the light in the at least part of the incident light passes through the substrate and then passes through the substrate. A microlens is formed on the incident side of the incident light on the substrate to collect the partial light flux of the incident light on the optical filter.

  According to the present invention, it is possible to reduce the size and increase the operation speed as compared with the means using a macro mechanical mechanism, and to improve the light utilization efficiency, and to use the optical device. A variable filter device, a projection display device, and a shutter device can be provided.

  Hereinafter, an optical device, a variable filter device, a projection display device, and a shutter device according to the present invention will be described with reference to the drawings.

  [First Embodiment]

  FIG. 1 is a schematic configuration diagram showing a projection display device (projector) according to a first embodiment of the present invention. For convenience of explanation, as shown in FIG. 1, an X axis, a Y axis, and a Z axis that are orthogonal to each other are defined (the same applies to the drawings described later). The direction of the arrow in the Z-axis direction is called the + Z direction or + Z side, and the opposite direction is called the -Z direction or -Z side, and the same applies to the X-axis direction and the Y-axis direction. The Z axis is parallel to the optical axis of the projection display device.

  As shown in FIG. 1, the projection display apparatus according to the present embodiment includes a light source 1, an optical device 2, a variable filter device 4 having a device control circuit 3 for controlling the optical device 2, a spatial light modulator 5, and an image. A signal control circuit 6 and a projection lens 7 as a projection optical system for irradiating a screen 8 with a display image are provided. In the present embodiment, a transmissive modulator is used as the spatial light modulator 5, but a reflective modulator may be used. In this embodiment, a liquid crystal panel is used as the spatial light modulator 5, but another spatial light modulator may be used.

  In the present embodiment, the light source 1 includes light in a red wavelength band (R light), light in a green wavelength band (G light), and light in a blue wavelength band (R light) as light in a plurality of discrete wavelength bands. B light). Specifically, for example, an LED in which three LEDs of R, G, and B are used as a set is used as the light source 1, and the three wavelength bands ΔλR, ΔλG, and ΔλB of the light emitted from the light source 1 are 470 nm. There are relatively narrow wavelength bands near, 550 nm, and 650 nm. Further, as the light source 1, for example, a halogen lamp that emits light having a continuous spectrum in the visible region, and a transmission type or a reflection type that obtains discrete R light, G light, and B light by filtering the light. A combination of a three-band optical filter may be used.

  In the present embodiment, the light from the light source 1 enters the optical device 2 as a parallel light beam. If necessary, the light from the light source 1 may be converted into a parallel light beam using a collimator lens or the like. Further, the light incident on the optical device 2 is not necessarily a parallel light flux.

  The image signal control circuit 6 processes the input image signal, and sequentially circulates the R light selection signal, the G light selection signal, and the B light selection signal as color selection signals to the device control circuit 3 of the variable filter device 4. On the other hand, the image signal of the color component is supplied to the spatial light modulator 5 in synchronization with the selection signal of each color. The device control circuit 3 controls the optical device 2 according to the color selection signal from the image signal control circuit 6, so that the optical device 2 of the variable filter device 4 indicates the color selection signal out of the light from the light source 1. Color light is selectively transmitted (transmitted in the present embodiment) and incident on the spatial light modulator 5. Accordingly, the variable filter device 4 selectively allows the R light, the G light, and the B light to pass through cyclically under the control of the image signal control circuit 6. For example, the variable filter device 4 does not allow the G light and the B light to pass when the R light is allowed to pass. The spatial light modulator 5 modulates the color light received from the optical device 2 of the variable filter device 4 with the image signal of the corresponding color component from the image signal control circuit 6, and the image light (modulated light) of the color. Generate. Therefore, the spatial light modulator 5 sequentially receives the R light, G light, and B light from the variable filter device 4, modulates the color light with an image signal of a color component synchronized with the light, and converts the image light of the color. Generate.

  In this manner, the R, G, and B image lights are sequentially and cyclically sent from the spatial light modulator 5 and projected onto the screen 8 by the projection lens 7. Therefore, by switching the R light, the G light, and the B light at a relatively high speed, the viewer observes the image as a full color image.

  FIG. 2 is a schematic plan view schematically showing the optical device 2 in FIG. Note that FIG. 2 is greatly simplified and shows only the substrate 11, the rotating plate 12, and the optical filter 13. FIG. 3 is a schematic plan view schematically showing two adjacent unit elements 10 in FIG. FIG. 4 is a schematic cross-sectional view along the line A-A ′ in FIG. 3. FIG. 5 is a schematic cross-sectional view along the line B-B ′ in FIG. 3. 2 and 3, the optical filter 13 is hatched.

  In the present embodiment, the optical device 2 includes a substrate 11 such as a Pyrex (registered trademark) glass substrate or a sapphire substrate that is transparent to visible light including R light, G light, and B light described above, 4 × 4 elements 10 arranged two-dimensionally on a substrate 11 are provided. Of course, the number of elements 10 is not limited to this. The + Z side surface of the substrate 11 is parallel to the XY plane.

  Each element 10 includes a rotating plate 12 as a movable portion whose attitude with respect to an angle can change with respect to the substrate 11, and a transmission type optical filter 13 provided on the rotating plate 12 and having wavelength selection characteristics. And an optical filter 13 in which the wavelength selection characteristic changes according to the incident angle of the incident light with respect to. The optical filter 13 of each element 10 receives a partial light flux of incident light from the light source 1.

  The rotating plate 12 is formed in a rectangular flat plate shape by a SiN (SiNx) film 21, and a step 12 a for increasing rigidity is formed around the rotating plate 12. Note that the SiN film is transparent to light in the visible region. The central part of the + Y side of the rotating plate 12 and the central part of the −Y side of the rotating plate 12 are supported by a post 14 rising from the substrate 11 via a torsion hinge 15, and the rotating plate 12 is connected to the Y axis by the torsion hinge 15. It is supported so as to be rotatable around parallel rotation axes. When the rotating plate 12 rotates, the inclination angle θ of the rotating plate 12 with respect to the XY plane (that is, the inclination angle with respect to the + Z side surface of the substrate 11) changes. When the later-described electrostatic force is not applied to the rotating plate 12, the rotating plate 12 is returned to a posture parallel to the XY plane by the restoring force of the torsion hinge 15. The SiN film 21 constituting the rotating plate 12 extends to the torsion hinge 15 and the post 14 as it is.

  A movable electrode 16 made of an ITO film 22 is formed on the rotating plate 12, and an optical filter 13 is further formed on the movable electrode 16. The ITO film 22 is transparent to light in the visible region. As shown in FIG. 3, the optical filter 13 is formed in a large area of the flat portion of the rotating plate 12 except for the vicinity of the step 12 a around the rotating plate 12. The movable electrode 16 is also formed in the same region of the rotating plate 12. As shown in FIG. 5, the ITO film 22 constituting the movable electrode 16 extends to the torsion hinge and the post 14 as a part of the wiring of the movable electrode 16, and is formed on the SiN film 21 at the post 14. It is connected to a wiring 17 on the substrate 11 made of an ITO film through a contact hole. The movable electrodes 16 of all the elements 10 are electrically connected in common by the wiring 17. In the present embodiment, each of the two posts 14 is connected to the two wirings 17, but the movable electrode 16 may be connected to only one wiring 17. The torsion hinge 15 and the post 14 are constituted by a SiN film 21 extending from the rotating plate 12 and an ITO film 22 extending from the movable electrode 16.

In this embodiment, the optical filter 13 has a wavelength selection characteristic described later by a dielectric multilayer film (for example, a dielectric multilayer film having a structure in which a large number of alternating layers of SiO ₂ layers and Nb ₂ O ₅ layers are stacked). It is configured to have. When the incident angle of the incident light with respect to the dielectric multilayer film changes, the effective thickness of each layer changes according to the incident angle, so that the wavelength selection characteristics change according to the incident angle. For example, when the dielectric multilayer film has a bandpass characteristic as a wavelength selection characteristic regarding the transmission characteristic, the transmission wavelength band shifts to the short wavelength side as the inclination of incident light with respect to the normal direction of the dielectric multilayer film increases. I will do it. The wavelength selection characteristics of the optical filter 13 will be described in detail later. The optical filter 13 is not limited to a dielectric multilayer film, and may be composed of, for example, a photonic crystal.

  On the substrate 11, a first fixed electrode 18 a made of an ITO film 22 facing the −X side region of the movable electrode 16 and a second fixed film 18 a made of the ITO film 22 facing the + X side region of the movable electrode 16. A fixed electrode 18b is formed. The first fixed electrode 18a is connected to the wiring 19a formed by extending the ITO film 22 constituting the first fixed electrode 18a, and the second fixed electrode 18b is formed by extending the ITO film 22 constituting the first fixed electrode 18a as it is. It is connected to the wiring 19b. The first fixed electrodes 18a of all the elements 10 are electrically connected in common by the wiring 19a, and the second fixed electrodes 18b of all the elements 10 are electrically connected in common by the wiring 19b.

The wirings 17, 19 a, 19 b and the fixed electrodes 18 a, 18 b are covered with an insulating film 20 made of a SiN film or a SiO ₂ film that is transparent to light in the visible region.

  Since the element 10 has the movable electrode 16 and the first and second fixed electrodes 18a and 18b as described above, when a voltage is applied between the movable electrode 16 and the first fixed electrode 18a, An electrostatic force as a driving force acts between the rotating plate 12 and the -X side region of the movable electrode 16 approaches the substrate 11 side around the rotation axis parallel to the Y axis connecting the two torsion hinges 15. Rotate in the direction of rotation. The rotating plate 12 abuts on a stopper 31a made of a SiN film or the like as a contacted portion provided on the substrate 11 at a position opposite to the −X side region of the movable electrode 16, and is held in that state. The In this state, the height of the stopper 31a is set so that the inclination angle (inclination angle with respect to the XY plane) θ of the rotating plate 12 becomes the predetermined first inclination angle θ1. The first tilt angle θ1 will be described in detail later. For example, the first tilt angle θ1 is a tilt angle at which the optical filter 13 selectively transmits R light.

  Similarly, when a voltage is applied between the movable electrode 16 and the second fixed electrode 18b, an electrostatic force as a driving force acts between the two, and the rotating plate 12 has two torsion hinges. 15, the region on the + X side of the movable electrode 16 rotates in a rotation direction approaching the substrate 11 side around a rotation axis parallel to the Y axis connecting 15. The rotating plate 12 abuts on a stopper 31b made of a SiN film or the like as a contacted portion provided on the substrate 11 at a position facing the + X side region of the movable electrode 16, and is held in that state. . In this state, the height of the stopper 31b is set so that the inclination angle θ of the rotating plate 12 becomes the predetermined second inclination angle θ2. The second inclination angle θ2 is different from the first inclination angle, and θ2 <θ1. In the present embodiment, the height of the stopper 31a and the height of the stopper 31b are made different in order to make the first and second inclination angles θ1 and θ2 different. As will be described in detail later, the second inclination angle θ2 is, for example, an inclination angle at which the optical filter 13 selectively transmits G light. The stoppers 31a and 31b are not necessarily provided on the substrate 11. For example, when a voltage is applied between the movable electrode 16 and the first fixed electrode 18a without providing the stopper 31a, the movable electrode 16 is provided. The end portion on the −X side may contact the insulating film 20 on the substrate 11 and be held in that state.

  When no voltage is applied between the movable electrode 16 and the first fixed electrode 18a or between the movable electrode 16 and the second fixed electrode 18b, the restoring force of the torsion hinge 15 The posture in which the rotating plate 12 is parallel to the XY plane, that is, the inclination angle θ of the rotating plate 12 returns to 0 degrees. As will be described in detail later, when the inclination angle θ is 0 degree, for example, the optical filter 13 is set so as to selectively transmit the B light.

  In the present embodiment, the optical device 2 is configured as a transmission type, and the substrate 11 side (that is, the −Z side) is the light incident side. As described above, since the substrate 11, the insulating film 20, the fixed electrodes 18a and 18b, the rotating plate 12, the movable electrode 16, and the like are transparent to light in the visible region, R light, G light, and B from the light source 1 are used. The light is not blocked.

  In the present embodiment, on the light incident side of the substrate 11, a microlens 11 a that condenses incident light on the optical filter 13 is formed on-chip corresponding to the optical filter 13 of each element 10. Has been. In the present embodiment, the microlens 11 a is formed of the same material as the substrate 11 by processing the substrate 11, but may be formed of a material different from that of the substrate 11. In the present embodiment, by using the microlens 11a, it is possible to effectively use light that enters the optical filter 13 and cannot enter the optical filter 13 without the microlens 11a. Thus, the light utilization efficiency can be further increased. In addition, if a lens having a good light collection rate is used as the microlens 11a, it is possible to avoid a portion where wiring and electrodes are arranged from the optical path. In such a case, it is not always necessary to configure wiring and electrodes using a transparent electrode material.

  However, it is not always necessary to form the microlens 11a. In this case, light that does not enter the optical filter 13 may be shielded by a light shielding unit (not shown) as necessary. When the microlens 11a is not formed in this way, the optical filter 13 side (that is, the + Z side) may be the light incident side, contrary to the present embodiment. However, when the optical filter 13 side is the light incident side, a microlens array configured separately from the optical device 2 may be arranged on the + Z side of the optical filter 13 to increase the light use efficiency.

  In the present embodiment, as described above, the movable electrodes 16 of all the elements 10 are electrically connected in common, and the first fixed electrodes 18a of all the elements 10 are electrically connected in common, Since the second fixed electrodes 18b of the elements 10 are electrically connected in common, wiring is performed so that a drive signal is supplied to all the elements 10 in common, and rotation of all the elements 10 is performed. The inclination angles of the plates 12 are always substantially the same. Moreover, in this Embodiment, the optical filter 13 of all the elements 10 is comprised completely the same, Thereby, the optical filter 13 of all the elements 10 is the case where the inclination angle of the rotating plate 12 is the same ( That is, in the case where the incident angles of incident light with respect to the optical filter 13 are the same), they have substantially the same wavelength selectivity.

  In the present embodiment, the part other than the optical filter 13 in the element 10 constitutes one microactuator. And the part except each optical filter 13 among the some elements 10 which comprise the optical device 2 comprises the microactuator array provided with the some microactuator.

  Next, an example of a method for manufacturing the optical device 2 will be described with reference to FIGS. 6 to 8 are schematic cross-sectional views schematically showing the state of each step in this manufacturing method, and a cross section taken along the line AA ′ in FIG. 3 (however, only a cross section of one element 10). It corresponds to. In addition, the material and dimension in the following description are illustrations, and are not limited to them.

First, an ITO film having a thickness of 0.3 μm is formed on a substrate 11 such as a Pyrex glass substrate or a sapphire substrate, and this ITO film is patterned into shapes such as fixed electrodes 18a and 18b and wirings 17, 19a and 19b. . Next, an insulating film 20 having a thickness of 0.5 μm made of a SiN film or a SiO ₂ film is formed on the entire surface of the substrate 11 (FIG. 6A).

  Next, an island-shaped resist 41a having a height of 3 μm as a sacrificial layer aligned with the stopper 31a and an island-shaped resist 41b having a height of 6 μm as a sacrificial layer aligned with the stopper 31b are formed on the insulating film 20. (FIG. 6B).

  Next, a 0.3 μm SiN film is formed, and this SiN film is patterned in accordance with the shapes of the stoppers 31a and 31b (FIG. 6C). At this time, minute openings (not shown) are formed in the stoppers 31a and 32b so that the resists 41a and 41b can be removed later.

  Subsequently, a resist 42 having a thickness of 12 μm as a sacrificial layer is applied to the entire surface of the substrate in the state shown in FIG. 6C (FIG. 6D). Further, a resist 43 having a thickness of 3 μm is formed in an island shape on the resist 42 as a sacrificial layer in accordance with the rotating plate 12 (FIG. 7A). Next, an opening corresponding to the contact hole in the post 14 (a square opening having a side of 5 μm) is formed in the resist 43 and the insulating film 20.

  Thereafter, a SiN film 21 is formed, and this SiN film 21 is patterned into the shape of the rotating plate 12, the post 14 and the torsion hinge 15 (FIG. 7B). At this time, an opening corresponding to the contact hole in the post 14 is formed in the SiN film 21.

Next, an ITO film 22 having a thickness of 0.3 μm is formed, and this ITO film 22 is patterned into a shape of a part of the movable electrode 16 and its wiring. Further, a dielectric multilayer film having a total thickness of 4 μm is formed by laminating a number of alternating layers of SiO ₂ layers and Nb ₂ O ₂ layers, and this dielectric multilayer film is patterned into the shape of the optical filter 13. (FIG. 7 (c)).

  Next, a resist 44 as a protective layer is formed on the substrate in the state of FIG. Further, a resist 45 exposed and developed with a gray-tone mask or the like is formed on the lower surface of the substrate 11 so as to have a curved surface matching the shape of the microlens 11a (FIG. 8A).

  Thereafter, the lower surface side of the substrate 11 is dry-etched using the resist 45 as a mask so that the lower surface side of the substrate 11 becomes the microlens 11a (FIG. 8B).

  Finally, the resists 41a, 41b, 42 to 44 are removed by a plasma ashing method or the like. Thereby, the optical device 2 is completed.

  Here, the wavelength selection characteristic of the optical filter 13 will be described with reference to FIG. FIG. 9 schematically shows the relationship between the wavelength bands ΔλR, ΔλG, ΔλB of the discrete R light, G light, and B light from the light source 1 and the discrete transmission wavelength bands Δλ1, Δλ2, Δλ3 of the optical filter 13. FIG. 9A shows a case where the tilt angle θ of the rotary plate 12 is 0 °, FIG. 9B shows a case where the tilt angle θ of the rotary plate 12 is the second tilt angle θ2, and FIG. The case where the inclination angle θ of the rotating plate 12 is the first inclination angle θ1 (> θ2) described above is shown.

  As described above, in the present embodiment, the wavelength component of the light from the light source 1 has only discrete wavelength bands ΔλR, ΔλG, ΔλB of the discrete R light, G light, and B light in the visible region. .

  In this embodiment, as shown in FIG. 9, the optical filter 13 has bandpass characteristics (so-called three-bandpass characteristics) having three discrete transmission wavelength bands Δλ1, Δλ2, and Δλ3 in the visible region. Have. As the rotating plate 12 is tilted (that is, as the tilt angle θ is increased), the effective thickness of each layer of the dielectric multilayer film constituting the optical filter 13 is increased. Therefore, as shown in FIG. Δλ1, Δλ2, and Δλ3 shift to the short wavelength side. In the present embodiment, the incident angle of the incident light with respect to the substrate 11 is unchanged.

  In this embodiment, when θ = 0 °, as shown in FIG. 9A, the transmission wavelength band Δλ1 overlaps ΔλB, but the other transmission wavelength bands Δλ2 and Δλ3 are in any wavelength band ΔλR, Neither ΔλG nor ΔλB overlaps. When θ = θ2, as shown in FIG. 9B, the transmission wavelength band Δλ2 overlaps with ΔλG, but the other transmission wavelength bands Δλ1, Δλ3 overlap with any of the wavelength bands ΔλR, ΔλG, ΔλB. Don't be. Further, when θ = θ1, as shown in FIG. 9C, the transmission wavelength band Δλ3 overlaps with ΔλR, but the other transmission wavelength bands Δλ1, Δλ2 overlap with any of the wavelength bands ΔλR, ΔλG, ΔλB. Don't be. In the present embodiment, the first and second inclination angles θ1, θ2 and transmission wavelength bands Δλ1, Δλ2, Δλ3 are set so as to satisfy such a relationship. For example, by appropriately setting the number of layers constituting the optical filter 13, the layer thickness, and the like, the transmission wavelength bands Δλ 1, Δλ 2, and Δλ 3 can be appropriately set by providing the optical filter 13 with three band pass characteristics. Is well known.

  Therefore, in the present embodiment, when the tilt angle θ of the rotating plate 12 is set to 0 °, the optical filter 13 selectively transmits only the B light, and when the tilt angle θ of the rotating plate 12 is set to the second tilt angle θ2. The optical filter 13 selectively transmits only the G light, and when the tilt angle θ of the rotating plate 12 is set to the first tilt angle θ1, the optical filter 13 selectively transmits only the R light.

  Of course, even when any one of R light, G light, and B light is selectively transmitted, the relationship between the inclination angles θ1, θ2, the wavelength bands ΔλR, ΔλG, ΔλB and the transmission wavelength bands Δλ1, Δλ2, Δλ3 is It is not limited to the example shown in FIG. For example, when θ = 0 °, only one of the transmission wavelength bands Δλ1, Δλ2, and Δλ3 overlaps only one of the wavelength bands ΔλR, ΔλG, and ΔλB, When θ = θ1, only one of the remaining two transmission wavelength bands of the transmission wavelength bands Δλ1, Δλ2, and Δλ3 is the remaining two of the wavelength bands ΔλR, ΔλG, and ΔλB. Only one of the wavelength bands overlaps, and when θ = θ2, only the remaining one of the transmission wavelength bands Δλ1, Δλ2, Δλ3 is included in the wavelength bands ΔλR, ΔλG, ΔλB. The relationship may be set so as to overlap with only the remaining one wavelength band.

Here, FIGS. 11 to 13 show examples of simulation results when the relationship shown in FIG. 9 is set. In this simulation, it is assumed that the light transmitted through the light from the halogen lamp through the optical filter having the three-band characteristics shown in FIG. 10 (the optical filter for producing incident light) is incident light on the optical filter 13. FIG. 11 shows the simulation result of the spectrum of the light after passing through the optical filter 13 when this incident light is incident on the optical filter 13 in the normal direction (corresponding to θ = 0 °). Show. Further, when this incident light is incident on the optical filter 13 with an inclination of 30 ° with respect to the normal direction of the optical filter 13 (corresponding to θ = θ2 = 30 °), the light is transmitted through the optical filter 13. The simulation result of the spectrum of light is shown in FIG. Further, when the incident light is incident on the optical filter 13 with an inclination of 40 ° with respect to the normal direction of the optical filter 13 (corresponding to θ = θ1 = 40 °), the light is transmitted through the optical filter 13. The simulation result of the spectrum of light is shown in FIG. In this simulation, it is assumed that the optical filter 13 is a laminated film of 80 layers, all odd-numbered layers from the light incident side are 50 nm thick SiO ₂ layers, and even-numbered layers from the light incident side are All of them were Nb ₂ O ₅ layers having a thickness of 50 nm.

  From FIG. 10 to FIG. 13, if the configuration as in the simulation is adopted as the configuration of the optical filter 13 and the first and second tilt angles θ1 and θ2 are set to 40 ° and 30 °, respectively, θ = 0. In the case of °, only the B light is selectively transmitted through the optical filter 13, in the case of θ = θ2, only the G light is selectively transmitted through the optical filter 13, and in the case of θ = θ1, only the R light is optically filtered. It can be seen that 13 is selectively transmitted.

  In the present embodiment, when the device control circuit 3 in FIG. 1 receives the R light selection signal from the image signal control circuit 6, the device control circuit 3 is interposed between the movable electrodes 16 of all the elements 10 and the first fixed electrodes 18a. A voltage is applied to θ = θ1, and when a G light selection signal is received, a voltage is applied between the movable electrode 16 and the second fixed electrode 18b of all the elements 10 to make θ = θ2, and B light When a selection signal is received, no voltage is applied between the movable electrode 16 and the fixed electrodes 18a and 18b of all the elements 10, and θ = 0 °.

  In the present embodiment, the variable filter device 4 including the optical device 2 and the device control circuit 3 described above is used, and the wavelength of light to be transmitted is changed using the wavelength selection characteristic of the optical filter 13, so that the variable filter Compared with the case where a liquid crystal device using polarized light is used instead of the apparatus 4 as in the prior art, the light use efficiency is greatly increased.

  Further, in the present embodiment, the wavelength of light to be transmitted is not changed by moving a single large optical filter (that is, not using a macro mechanical mechanism). The individual optical filters 13 are provided on the movable parts (rotary plates 12 in the present embodiment) of the individual microactuators of the array, and the plurality of optical filters 13 are respectively moved by the microactuators, so that they are the same all at once. Perform a color selection operation. Therefore, each optical filter 13 can be reduced in size and weight. Therefore, the operation speed of each optical filter 13 can be increased, and the operation speed of color selection can be increased. Further, the variable filter device 4 can be reduced in size as compared with the case where the variable filter device is configured using a macro mechanical mechanism.

  Thus, according to the present embodiment, the variable filter device 4 can be reduced in size and speeded up as compared with the means using a macro mechanical mechanism, and the light utilization efficiency can be improved. Can be increased. Therefore, according to the present embodiment, it is possible to reduce the size of the projection display device as a whole and increase the light use efficiency.

  In the present embodiment, as described above, the optical filters 13 of all the elements 10 have the same wavelength selection characteristics, and the inclination angles of the rotating plates 12 of all the elements 10 are always the same. However, the present invention is not necessarily limited to this. For example, all the elements 10 are divided into several groups, the optical filters 13 of the elements 10 of each group are configured to have different wavelength selection characteristics for each group, and the device control circuit 3 is connected to the image signal control circuit 6. When the R light selection signal is received, a different drive signal is applied to each group, and the tilt angle of the rotating plate 12 is made different for each group, so that the optical filters 13 of the elements 10 of all the groups have the R light. May be configured to transmit selectively. In this case, for example, the fixed electrodes 18a and 18b may be commonly connected to each group and wired so that independent drive signals can be applied between different groups.

  [Second Embodiment]

  FIG. 14 is a schematic plan view schematically showing two adjacent unit elements 60 of the optical device 52 used in the projection display apparatus according to the second embodiment of the present invention, and corresponds to FIG. . FIG. 15 is a schematic sectional view taken along line C-C ′ in FIG. 14. 14 and 15, the same or corresponding elements as those in FIGS. 3 and 4 are denoted by the same reference numerals, and redundant description thereof is omitted.

  The projection display device according to the present embodiment is different from the projection display device according to the first embodiment in that an optical device 52 is used instead of the optical device 2, and accordingly, the device control circuit 3 performs an optical operation. The only difference is that the signal supplied to the device 52 is not a voltage signal but a current signal described later.

  The optical device 52 is different from the optical device 2 in the points described below. Although not shown in the drawing, in the optical device 52, a plurality of unit elements 60 instead of the unit elements 10 are two-dimensionally arranged on the substrate 11.

  The optical device 52 is basically different from the optical device 2 in that the rotating plate 12 as a movable part is rotatably supported in the optical device 2, while the optical device 52 is described below as described below. The cantilever structure is adopted.

  Each element 60 includes a movable plate 62 as a movable portion that can change its attitude with respect to the substrate 11 and an optical filter 13 provided on the movable 62 (this optical filter 13 is the same as the optical filter 13 of the optical device 2). The same).

  The movable plate 62 is formed in a rectangular flat plate shape by a lower SiN film 71 and an upper SiN film 72, and a step 62a for increasing rigidity is formed around the movable plate 62. The optical filter 13 is formed on the SiN film 72.

  Both side portions on one side of the −X side of the movable plate 62 are supported via posts 65 rising from the substrate 11 via hinges 65 that form leaf springs, and the movable plates 62 are supported by the hinges 65 so as to be tiltable. In this embodiment, a cantilever structure in which one end side is supported by the hinge 65 is employed. When the Lorentz force described later is not applied to the movable plate 62, the movable plate 62 is returned to a posture parallel to the XY plane by the restoring force of the hinge 65 (in this embodiment, the spring force). It has become. The SiN films 71 and 72 constituting the movable plate 62 extend to the hinge 65 and the post 64 as they are.

  As shown in FIG. 14, between the SiN films 71 and 72, from the + Y side post 64, the + Y side hinge 65, the vicinity of the + Y side of the movable plate 62, the vicinity of the + X side of the movable plate 62, and the movable A wiring 63 made of an Al film is formed in the vicinity of the −Y side edge of the plate 62, passing through the −Y side hinge 65, and reaching the −Y side post 64. In the present embodiment, the wiring 63 is arranged so as not to overlap the optical filter 13. However, in the case where the wiring 63 is arranged so as to overlap, the wiring 63 may be formed of an ITO film or the like. A non-illustrated permanent magnet (may be an electromagnet or the like) generates a substantially uniform magnetic field toward one side along the X-axis direction.

  Of the wiring 63, a linear path 63a extending in the Y-axis direction along one side of the + X side of the movable plate 62 is disposed in the magnetic field of the magnet, and generates a Lorentz force as a driving force when energized. (Current path for Lorentz force). The other part of the wiring 63 is a supply path for supplying current to the Lorentz force current path 63a. Since the magnetic field is generated by the magnet, the Lorentz force in the −Z direction or + Z direction acts on the Lorentz force current path 63a (and hence the movable plate 62) according to the direction of the current flowing through the Lorentz force current path 63a. To do. In the present embodiment, the Lorentz force current path 63a serves as a driving force generator, but the driving force is not necessarily limited to the Lorentz force. However, since the Lorentz force has good linearity with respect to the current, the magnitude of the driving force is adjusted, and the movable plate 62 is stably held at a desired inclination angle in which the driving force and the spring force of the hinge 65 are balanced. For this purpose, Lorentz force is preferably used as the driving force.

  The hinge 65 and the post 64 are composed of SiN films 71 and 72 and wirings 63 extending from the movable plate 62.

One end of the wiring 63 is connected to a wiring 66 a made of an Al film formed on the substrate 11 through a contact hole formed in the SiN film 71 at a post 64 on the + Y side. Similarly, the other end of the wiring 63 is connected to a wiring 66 b made of an Al film formed on the substrate 11 through a contact hole formed in the SiN film 71 in the post 64 on the −Y side. The wirings 66a and 66b are covered with an insulating film 80 made of a SiN film or a SiO ₂ film.

  One end of the Lorentz force current path 63a of all the elements 60 is electrically connected in common by the wiring 66a. Similarly, one end of the Lorentz force current path 63a of all the elements 60 is electrically connected in common by the wiring 66b. Thereby, the Lorentz force current paths 63a of all the elements 60 are connected in parallel. Therefore, a Lorentz force current, which is a drive signal, is supplied to the Lorentz force current path 63a of all the elements 60 in common. In the Lorentz force current path 63a of all the elements 60, Lorentz force in the same direction is generated. Instead of the Lorentz force current paths 63a of all the elements 60 being connected in parallel, the Lorentz force current paths 63a of all the elements 60 may be connected in series, or the Lorentz force current paths 63a may be connected in series for each of a plurality of elements. The series connection bodies may be connected in parallel. Also in these cases, the Lorentz force current, which is a drive signal, is supplied to the Lorentz force current path 63a of all the elements 60 in common.

  In this optical device 52, when a Lorentz force current is passed through the Lorentz force current path 63a, the movable plate 62 is tilted to an inclination angle where the Lorentz force generated in the Lorentz force current path 63a and the spring force of the hinge 65 are balanced. Hold. Therefore, the inclination of the movable plate 62 to be held can be changed by changing the magnitude of the current flowing through the Lorentz force current path 63a. The direction of the Lorentz force may be the + Z direction or the −Z direction.

  Also in the present embodiment, since the optical filter 13 is the same as in the first embodiment, the device control circuit 3 receives the R light selection signal from the image signal control circuit 6 and thus the drive signal. As described above, a current having such a magnitude that the inclination angle (inclination section angle with respect to the XY plane) θ of all the elements 60 is set to the aforementioned first inclination angle θ1 is supplied to the Lorentz force current path 63a of all the elements 60. Shed. Further, when the device control circuit 3 receives the G light selection signal from the image signal control circuit 6, the tilt angle θ of the movable plates 62 of all the elements 60 is set to the second tilt angle θ2 described above as a drive signal. A current having such a magnitude is supplied to the Lorentz force current path 63a of all the elements 60. Further, when the device control circuit 3 receives the B light selection signal from the image signal control circuit 6, the Lorentz force of all the elements 60 is set so that the inclination angle θ of the movable plates 62 of all the elements 60 becomes 0 °. No current is passed through the current path 63a.

  In the present embodiment, the part of the element 60 other than the optical filter 13 constitutes one microactuator. And the part except each optical filter 13 among the some elements 60 which comprise the optical device 52 comprises the microactuator array provided with the some microactuator.

  Next, an example of a method for manufacturing the optical device 52 will be described with reference to FIGS. 16 to 18 are schematic cross-sectional views schematically showing the state of each step in this manufacturing method, and correspond to the cross-sectional view shown in FIG. However, in FIGS. 16 to 18, only the cross section of one element 60 is shown. In addition, the material and dimension in the following description are illustrations, and are not limited to them.

First, an Al film having a thickness of 0.3 μm is formed on a substrate 11 such as a Pyrex glass substrate or a sapphire substrate, and this Al film is patterned into a shape such as wirings 66a and 66b. Next, an insulating film 80 having a thickness of 0.5 μm made of SiN film or SiO ₂ film is formed on the entire surface of the substrate 11 (FIG. 16A).

  Next, a resist 91 having a thickness of 3 μm is formed as a sacrificial layer on the entire insulating film 20 (FIG. 16B). Further, a resist 92 having a thickness of 3 μm as a sacrificial layer matched with the movable plate 62 is formed in an island shape on the resist 91 (FIG. 16C).

  Subsequently, an opening (a square opening with a side of 5 μm) corresponding to the contact hole in the post 64 is formed in the resist 91 and the insulating film 80 (FIG. 16D).

  Thereafter, a SiN film 71 is formed, and this SiN film 71 is patterned into the shape of the movable plate 62, the post 64, and the hinge 65 (FIG. 17A). At this time, an opening corresponding to the contact hole in the post 64 is formed in the SiN film 71.

  Next, an Al film having a thickness of 0.3 μm is formed, and this Al film is patterned into the shape of the wiring 63 (FIG. 17B). Further, a 0.3 μm thick SiN film 72 is formed thereon, and the SiN film 72 is patterned into the shape of the movable plate 62, the post 64, and the hinge 65 (FIG. 17C).

Next, a dielectric multilayer film having a structure in which a large number of alternating layers of SiO ₂ layers and Nb ₂ O ₂ layers are stacked and having a total layer thickness of 4 μm is formed, and this dielectric multilayer film is formed into the shape of the optical filter 13. Patterning is performed (FIG. 17D).

  Next, a resist 93 as a protective layer is formed on the substrate in the state of FIG. Further, a resist 94 exposed and developed with a gray-tone mask or the like is formed on the lower surface of the substrate 11 so as to have a curved surface matching the shape of the microlens 11a (FIG. 18A).

  Thereafter, the lower surface side of the substrate 11 is dry-etched using the resist 94 as a mask so that the lower surface side of the substrate 11 becomes the microlens 11a (FIG. 18B).

  Finally, the resists 91 to 93 are removed by a plasma ashing method or the like. Thereby, the optical device 52 is completed.

  Also in this embodiment, the same advantages as those in the first embodiment can be obtained.

  By the way, the variable filter device (variable filter device including the optical device 52 and the device control circuit) employed in the projection display device according to the present embodiment may be modified as follows depending on the application. This modification will be described with reference to FIG. FIG. 19 is a diagram showing the relationship between the wavelength band ΔλRGB of the light spectrum from the light source 1 and the single wavelength band Δλ11 of the optical filter 13 in this modification. 19A shows a case where the tilt angle θ of the movable plate 62 is 0 °, FIG. 19B shows a case where the tilt angle θ increases, and FIG. 19C shows a case where the tilt angle θ further increases. Each case is shown.

  In this modification, a halogen lamp or the like that emits light having a continuous spectrum in the visible region is used as the light source 1, and the light having this continuous spectrum (in FIG. 19, the wavelength band is indicated by ΔλRGB). Then, the light is incident on the deformed optical device 52 as follows. In this modification, as the optical filter 13 of the optical device 52, a filter having a wavelength selection characteristic having a single transmission wavelength band Δλ11 is provided as shown in FIG. In this example, by continuously changing from θ = 0 ° shown in FIG. 19A to the angle shown in FIG. 19C, the wavelength of the selectively transmitted light is substantially continuously from G light to B light. Can be changed. If the microactuator is configured so that the variable range of the tilt angle of the movable plate 62 becomes larger and Δλ11 when θ = 0 ° is set near the R light, the tilt angle of the movable plate 62 is continuously changed. As a result, the wavelength of the selectively transmitted light can be continuously changed from substantially R light to B light. Therefore, if it deform | transforms in this way, it can use for the use which changes a passage wavelength continuously from R light to B light. Further, if the microactuator is configured so that the variable range of the tilt angle of the movable plate 62 becomes larger, and Δλ11 when θ = 0 ° is set in the vicinity of the R light, this single transmission wavelength band Δλ11 is obtained. The optical device 52 deformed to have can be used in place of the optical device 52 in the second embodiment. In this case, the device control circuit 3 may be switched to a state where no current is passed through the Lorentz force current path 63a, a state where a current for G light is passed, and a state where a current for B light is passed according to the color selection signal.

  In addition, the variable filter device employed in the first embodiment and the second embodiment may be configured to variably output two colors of light depending on the application. In this modification, for example, when only one of the G light and the B light is selectively output, as can be understood from FIG. 9, for example, the light source 1 (appropriately, if necessary) The optical filter 13 includes light components of two discrete wavelength bands ΔλG and ΔλB of G light and B light as light from the optical filter 13. May be configured to have bandpass characteristics (so-called two-bandpass characteristics) having two discrete transmission wavelength bands Δλ1 and Δλ2. At this time, for example, as shown in FIG. 20, the optical filter 13 of each element 60 is configured to have relatively wide transmission wavelength bands Δλ1 ′ and Δλ2 ′ instead of relatively narrow transmission wavelength bands Δλ1 and Δλ2. May be.

  [Third Embodiment]

  FIG. 21 is a schematic configuration diagram showing a shutter device 104 according to the third embodiment of the present invention.

  The shutter device 104 according to the present embodiment includes an optical device 102 and a device control circuit 103 that controls the optical device 102, and at least a part of the incident light from the light source 101 in the visible region according to the switching signal. Between an on state in which light in the wavelength band of light is allowed to pass and an off state in which light in the visible region of incident light from the light source 101 is not substantially passed.

  The light source 101 is the same as the light source 1 in the first embodiment, and the wavelength band of light from the light source 101 is three discrete and relatively narrow wavelength bands, that is, R light, G light, and B light. Are the wavelength bands ΔλR, ΔλG, and ΔλB.

  In the present embodiment, the light from the light source 101 enters the optical device 102 as a parallel light flux. If necessary, the light from the light source 1 may be converted into a parallel light beam using a collimator lens or the like. Further, the light incident on the optical device 102 is not necessarily a parallel light beam.

  The optical device 102 is configured in the same manner as the optical device 2 employed in the projection display device according to the first embodiment except for the points described below. The optical device 102 is different from the optical device 2 in that the second fixed electrode 18b and the stopper 31b are removed from each element 10 and the wiring 19b is also removed, and the wavelength selection of the optical filter 13 of each element 10 is performed. It is only a characteristic point.

  In this optical device 102, a voltage is applied between the fixed electrode 18a and the movable electrode 16, and the inclination angle θ of the rotating plate 12 is held at the inclination angle θ1, and between the fixed electrode 18a and the movable electrode 16. No voltage is applied to the rotating plate 12, and the tilt angle θ of the rotating plate 12 is switched to one of the states held at 0 °.

  FIG. 22 shows the wavelength bands ΔλR, ΔλG, ΔλB of discrete R light, G light, and B light from the light source 101 and the discrete transmission wavelength bands Δλ21, Δλ22, Δλ23 of the optical filter 13 of the optical device 102. It is a figure which shows a relationship typically. 22A shows the case where the tilt angle θ of the rotating plate 12 is 0 °, and FIG. 22B shows the case where the tilt angle θ of the rotating plate 12 is the tilt angle θ1.

  As described above, in the present embodiment, the wavelength component of the light from the light source 1 has only discrete wavelength bands ΔλR, ΔλG, ΔλB of the discrete R light, G light, and B light in the visible region. .

  In this embodiment, the optical filter 13 of each element 10 of the optical device 102 has a bandpass characteristic having three discrete transmission wavelength bands Δλ21, Δλ22, and Δλ23 in the visible region as shown in FIG. (So-called three-band pass characteristics). As the rotating plate 12 is tilted (that is, the tilt angle θ is increased), the effective thickness of each layer of the dielectric multilayer film constituting the optical filter 13 is increased. Δλ21, Δλ22, and Δλ23 shift to the short wavelength side. In the present embodiment, the incident angle of the incident light with respect to the substrate 11 is unchanged.

  In this embodiment, when θ = 0 °, as shown in FIG. 22A, the three transmission wavelength bands Δλ21, Δλ22, Δλ23 overlap with the three wavelength bands ΔλR, ΔλG, ΔλB, respectively. . On the other hand, when θ = θ1, the three transmission wavelength bands Δλ21, Δλ22, and Δλ23 do not overlap any of the wavelength bands ΔλR, ΔλG, and ΔλB. In the present embodiment, the optical filter 13 of each element 10 of the optical device 102 is set with an inclination angle θ1 and transmission wavelength bands Δλ21, Δλ22, and Δλ23 so as to satisfy such a relationship.

  Therefore, in this embodiment, when the tilt angle θ of the rotating plate 12 is set to 0 °, the optical filter 13 transmits all of the R light, G light, and B light, and the light after transmission is substantially the same as the light before transmission. It becomes white light. On the other hand, when the tilt angle θ of the rotating plate 12 is set to the tilt angle θ1, light in any wavelength band of R light, G light, and B light is not transmitted, and light from the light source 101 is completely shielded.

  Here, FIG. 23 and FIG. 24 show an example of simulation results when the relationship shown in FIG. 22 is set. In this simulation, the light transmitted through the optical filter having the three-band pass characteristic shown in FIG. FIG. 23 shows a simulation result of the spectrum of the light after passing through the optical filter 13 when this incident light is incident on the optical filter 13 in the normal direction (corresponding to θ = 0 °). Show. In addition, when this incident light is incident on the optical filter 13 with an inclination of 30 ° with respect to the normal direction of the optical filter 13 (corresponding to θ = θ1 = 30 °), the light is transmitted through the optical filter 13. The light spectrum simulation result is shown in FIG.

  23 and 24, if the configuration as in the simulation is adopted as the configuration of the optical filter 13 and the inclination angle θ1 is set to 30 °, the optical filter 13 is configured to emit R light when θ = 0 °. It can be seen that white light composed of G light and B light is transmitted and light in any wavelength band is shielded when θ = θ1.

  In the present embodiment, the device control circuit 103 in FIG. 21 receives the switching signal from the outside, and when the switching signal indicates the on state, the device control circuit 103 performs the operation of the movable electrodes 16 and the fixed electrodes 18a of all the elements 10. When no voltage is applied between them and θ = 0 °, and the switching signal indicates an off state, a voltage is applied between the movable electrode 16 and the fixed electrode 18a of all the elements 10 so that θ = θ1. To do.

  In the shutter device 104 according to the present embodiment, the optical device 102 and the device control circuit 103 described above are used, and light transmission is turned on / off using the wavelength selection characteristics of the optical filter 13. Instead of using a liquid crystal shutter that uses polarized light as in the prior art, the light use efficiency is significantly increased.

  Further, in the present embodiment, the wavelength of light to be transmitted is not changed by moving a single large optical filter (that is, not using a macro mechanical mechanism). The individual optical filters 13 are provided on the movable parts (rotary plates 12 in the present embodiment) of the individual microactuators of the array, and the plurality of optical filters 13 are respectively moved by the microactuators, so that they are the same all at once. Performs on / off switching operation. Therefore, each optical filter 13 can be reduced in size and weight. Therefore, the operation speed of each optical filter 13 can be increased, and the on / off operation speed can be increased. Further, the shutter device 104 can be reduced in size as compared with the case where the shutter device 104 is configured using a macro mechanical mechanism.

  Thus, according to the present embodiment, it is possible to reduce the size and increase the operation speed as compared with the means using a macro mechanical mechanism, and it is possible to increase the light utilization efficiency.

  Note that the relationship between the wavelength bands ΔλR, ΔλG, ΔλB and the discrete transmission wavelength bands Δλ1, Δλ2, Δλ3 of the optical filter 13 of the optical device 102 is not limited to the example shown in FIG. It is also possible to set so that white light composed of R light, G light, and B light is transmitted when = θ1, and light in any wavelength band is shielded when θ = 0 °.

  In the present embodiment, the optical device 102 is a modification of the optical device 2 employed in the first embodiment. However, instead of the optical device 102, the second embodiment is used. A modified version of the optical device 52 used in the above may be used. In this case, the optical filter 13 of each element 60 in the optical device 52 may be replaced with the same one as the optical filter 13 of the optical device 102 (that is, an optical device having wavelength selection characteristics shown in FIG. 22). In this case, when the switching signal indicates an off state, the device control circuit 102 sets the inclination angle (inclination section angle with respect to the XY plane) θ of all the elements 60 to the inclination angle θ1 as a drive signal. When a current of a magnitude is passed through the Lorentz force current path 63a of all the elements 60 and the switching signal indicates an ON state, all the elements 60 have all of the movable plates 62 to have an inclination angle θ of 0 °. No current flows through the Lorentz force current path 63a of the element 60.

  Incidentally, the shutter device 104 according to the third embodiment may be modified as follows. That is, even when the wavelength components of light from the light source 101 are ΔλR, ΔλG, and ΔλB, only light in one or two wavelength bands of ΔλR, ΔλG, and ΔλB is selectively transmitted in the on state. You may do it. In this case, for example, when only light in the wavelength bands of ΔλB and ΔλG is selectively transmitted in the on state, the optical filter 13 of each element 10 has a bandpass characteristic having only two transmission wavelength bands Δλ21 and Δλ22. What is necessary is just to comprise so that it may have.

  Further, the wavelength components of the light from the light source 101 are not limited to ΔλR, ΔλG, and ΔλB, and may include only one or two of them, for example. For example, when the light from the light source 101 includes only ΔλG, the optical filter 13 of each element 10 may be configured to have a single bandpass characteristic having only one transmission wavelength band Δλ22. In this case, for example, as shown in FIG. 25, the optical filter of each element 10 may be configured to have a short path characteristic that transmits a wavelength band ΔλS that is equal to or less than the cutoff wavelength.

  Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments.

  For example, the first and second embodiments are examples in which the variable filter device according to the present invention is used in a projection display device, but the application of the variable filter device according to the present invention is not limited to this. For example, it may be used to change the wavelength observed in a fluorescence microscope.

  In the variable filter device employed in the first and second embodiments and the shutter device according to the third embodiment and its modification, each unit element is arranged two-dimensionally. Depending on the case, they may be arranged one-dimensionally.

  The variable filter device employed in the first and second embodiments and the shutter device according to the third embodiment and its modification are configured as a transmission type, but are configured as a reflection type. Also good. In these devices, when a reflective configuration is employed, a reflective optical filter may be employed in place of the transmissive optical filter 13 in each element. At this time, if incident light is incident not from the substrate 11 side but from the optical filter side, the substrate 11 and the like need not be made of a transparent material. In this case, since no light enters the microlens 11a, it is not necessary to form the microlens 11a.

1 is a schematic configuration diagram illustrating a projection display device according to a first embodiment of the present invention. It is a schematic plan view which shows typically the optical device in FIG. FIG. 3 is a schematic plan view schematically showing two adjacent unit elements in FIG. 2. FIG. 4 is a schematic cross-sectional view along the line A-A ′ in FIG. 3. FIG. 4 is a schematic sectional view taken along line B-B ′ in FIG. 3. It is a schematic sectional drawing which shows each process of the manufacturing method of the optical device in FIG. 1 typically, respectively. It is a schematic sectional drawing which shows each process following the process shown in FIG. It is a schematic sectional drawing which shows each process following the process shown in FIG. It is a figure which shows typically the characteristic of the optical device in FIG. It is a figure which shows the characteristic of the optical filter for incident light creation used for simulation. It is a figure which shows an example of a simulation result. It is another figure which shows an example of a simulation result. It is another figure which shows an example of a simulation result. It is a schematic plan view which shows typically two adjacent unit elements of the optical device used with the projection type display apparatus by the 2nd Embodiment of this invention. FIG. 15 is a schematic cross-sectional view taken along line C-C ′ in FIG. 14. It is a schematic sectional drawing which shows typically each process of the manufacturing method of the optical device used with the projection type display apparatus by the 2nd Embodiment of this invention. It is a schematic sectional drawing which shows each process following the process shown in FIG. It is a schematic sectional drawing which shows each process following the process shown in FIG. It is a figure which shows typically the characteristic of the optical filter in a modification. It is a figure which shows typically the characteristic of the optical filter in another modification. It is a schematic block diagram which shows the shutter apparatus by the 3rd Embodiment of this invention. It is a figure which shows typically the characteristic of the optical filter of the optical device in FIG. It is a figure which shows an example of a simulation result. It is another figure which shows an example of a simulation result. It is a figure which shows typically the characteristic of the optical filter in another modification.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,101 Light source 2,102 Optical device 3,103 Device control circuit 4 Variable filter apparatus 5 Spatial light modulator 7 Projection lens 10,60 Element 11 Substrate 11a Micro lens 12 Rotating plate 13 Optical filter 15 Torsion hinge 62 Movable plate 104 Shutter apparatus

Claims (23)

There are a plurality of microactuators having movable parts that can change the posture with respect to the angle with respect to the substrate, and the movable parts of the plurality of microactuators are arranged one-dimensionally or two-dimensionally on one surface side of the substrate. Microactuator array
A transmission type or reflection type optical filter provided in the movable part of each microactuator and having a wavelength selection characteristic, wherein the wavelength selection characteristic changes according to an incident angle of incident light with respect to the optical filter; ,
An optical device comprising:   2. The optical device according to claim 1, wherein each of the optical filters of the optical device has a bandpass characteristic having one or more pass wavelength bands as the wavelength selection characteristic.   3. The optical device according to claim 1, wherein the optical filters of the optical device have substantially the same wavelength selection characteristics when the incident angles of incident light with respect to the optical filter are the same. .   The optical device according to claim 1, wherein the optical device is wired so that a drive signal is commonly supplied to the plurality of microactuators.   The movable portion of at least one microactuator of the plurality of microactuators includes a rotating portion supported by a torsion hinge so as to be rotatable around a predetermined rotation axis with respect to the substrate. The optical device according to any one of 1 to 4.   The at least one microactuator includes a first driving force applying unit capable of applying a first driving force in one rotation direction to the rotating unit, and a second driving in the other rotating direction of the rotating unit. The optical device according to claim 5, further comprising a second driving force applying unit capable of applying a force.   With respect to the at least one microactuator, when the rotating portion is rotated in the one rotation direction by the first driving force and the rotating portion is held in contact with the first contacted portion on the substrate side The angle of the rotating part with respect to the one surface of the substrate and the rotating part is rotated in the other rotating direction by the second driving force, and the rotating part is a second contacted part on the substrate side. The optical device according to claim 6, wherein an angle of the rotating portion with respect to the one surface of the substrate when held in contact with the substrate is different from each other.   The movable part of at least one microactuator of the plurality of microactuators has a cantilever structure, and the movable part is provided so as to generate a return force for returning to a predetermined posture. 5. The optical device according to claim 1, further comprising a driving force generator that can generate a driving force against the restoring force. 6.   9. The optical device according to claim 8, wherein the driving force generator is a current path that is arranged in a magnetic field and generates a Lorentz force by energization. A variable filter device that receives incident light and selectively passes a part of the wavelength band of the incident light that is variably selected within a predetermined wavelength region with respect to the predetermined wavelength region,
An optical device according to any one of claims 1 to 9, and a control unit that controls the optical device according to a selection signal,
Each optical filter of the optical device receives each partial light beam of the incident light,
The control unit is configured such that each of the light beams after the partial light beams of the incident light are transmitted or reflected by the optical filters of the optical device are wavelength components corresponding to the selection signal, and substantially each other. Controlling the position of the movable part of each microactuator so as to be light of the same wavelength component;
A variable filter device.   The variable filter device according to claim 10, wherein the predetermined wavelength region is a visible region. The light in the predetermined wavelength region of the incident light consists of light of a plurality of discrete wavelength bands,
Each optical filter of the optical device has a bandpass characteristic having a plurality of discrete pass wavelength bands as the wavelength selection characteristic,
Regarding each optical filter of the optical device, any one of the plurality of pass wavelength bands of the optical filter is any one of the plurality of wavelength bands of the incident light. The plurality of pass wavelength bands of the optical filter are set so that the other pass wavelength bands of the optical filter do not substantially overlap with other wavelength bands of the incident light when overlapping. The variable filter device according to claim 10 or 11.   The light of the plurality of discrete wavelength bands constituting the incident light is light of a red wavelength band, light of a green wavelength band, and light of a blue wavelength band. Variable filter device. The incident light has a continuous spectrum within the predetermined wavelength region;
Each optical filter of the optical device has a bandpass characteristic having a single pass wavelength band having a narrower bandwidth than the predetermined wavelength region as the wavelength selective characteristic,
12. The pass wavelength band of the optical filter is set so that the pass wavelength band of the optical filter overlaps the predetermined wavelength region with respect to each optical filter of the optical device. The variable filter device described. Each optical filter of the optical device is a transmissive optical filter,
The substrate is transparent to light in a part of the variably selected wavelength band in the predetermined wavelength region of the incident light;
Light in a part of the variably selected wavelength band within the predetermined wavelength region of the incident light passes through the substrate and then enters each optical filter of the optical device, or the incident light 15. The light in a part of the variably selected wavelength band within the predetermined wavelength region of the light passes through the optical filters and then passes through the substrate. 15. The variable filter device described in 1. After the light of a part of the variably selected wavelength band in the predetermined wavelength region of the incident light is transmitted through the substrate, the light enters the optical filter of the optical device,
The variable filter device according to claim 15, wherein a microlens for condensing a partial light flux of the incident light onto each of the optical filters is formed on the incident side of the incident light on the substrate. Upon receiving incident light including light in the red wavelength band, light in the green wavelength band, and light in the blue wavelength band, the light in the red wavelength band, light in the green wavelength band, and light in the blue wavelength band A variable filter device that selectively and sequentially passes through;
A spatial light modulator that sequentially receives the light of each color wavelength band from the variable filter device, and modulates the light of the wavelength band of the color with an image signal of a color component synchronized with the light;
A projection optical system that projects the modulated light obtained by the spatial light modulator;
With
17. A projection type display device, wherein the variable filter device according to claim 10 is used as the variable filter device. A first state that receives incident light and transmits light in at least a part of a wavelength band within a predetermined wavelength region of the incident light; and substantially transmits light within the predetermined wavelength region of the incident light. A shutter device capable of switching between a second state that is not allowed to pass through,
An optical device according to any one of claims 1 to 9, and a control unit that controls the optical device according to a switching signal,
Each optical filter of the optical device receives each partial light beam of the incident light,
When the switching signal indicates the first state, the control unit is configured such that each of the light after the partial light beams of the incident light are transmitted or reflected by the optical filters of the optical device, While controlling the attitude of the movable part of each microactuator so as to be light in the at least part of the wavelength band, and when the switching signal indicates the second state, each of the optical devices Controlling the attitude of the movable part of each microactuator so that the passing wavelength band of the optical filter does not substantially overlap any wavelength band of the incident light,
A shutter device characterized by that.   The shutter device according to claim 18, wherein the predetermined wavelength region is a visible region. The light in the predetermined wavelength region of the incident light is composed of light in a plurality of discrete wavelength bands,
Each optical filter of the optical device has a bandpass characteristic having a plurality of discrete pass wavelength bands as the wavelength selection characteristic,
With respect to each optical filter of the optical device, the plurality of optical filters so that light in the plurality of wavelength bands of the incident light overlaps with the plurality of pass wavelength bands of the optical filter in the first state, respectively. The shutter device according to claim 18 or 19, wherein a passing wavelength band of is set.   21. The light of the plurality of discrete wavelength bands constituting the incident light is light of a red wavelength band, light of a green wavelength band, and light of a blue wavelength band. Shutter device. Each optical filter of the optical device is a transmissive optical filter,
The substrate is transparent to light of the at least some wavelength bands in the predetermined wavelength region of the incident light;
The light of the at least part of the wavelength band within the predetermined wavelength region of the incident light passes through the substrate and then enters the optical filter of the optical device, or the light of the incident light The shutter device according to any one of claims 18 to 21, wherein light in the at least part of a wavelength band within a predetermined wavelength region passes through the substrate after passing through the optical filters. The light of the at least some of the incident light in the wavelength band passes through the substrate and then enters the optical filter of the optical device,
23. The shutter device according to claim 22, wherein a microlens for condensing a partial light beam of the incident light onto the optical filter is formed on the incident side of the incident light on the substrate.

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