JP4872453B2 - Microactuator, optical device and display device - Google Patents

Description

  The present invention relates to a microactuator, an optical device using the same, and a display device.

  Along with the development of MEMS (Micro-Electro-Mechanical System) technology, microactuators using this technology, optical devices such as DMD (Digital Micro-mirror Device) using this technology, and such optical devices were used. Various projection display devices have been proposed.

  For example, the following Patent Document 1 discloses a representative DMD. In this DMD, the mirror is held by a torsion hinge, the hinge is twisted and deformed by electrostatic force, the mirror is rotated to change its direction, and the incident light reflection direction is changed. A plurality of basic units are arranged in a one-dimensional or two-dimensional form to form a spatial light modulator, which is applied to an optical information processing apparatus, a projection display apparatus, an electrostatographic printing apparatus, and the like.

  An optical device that changes the reflection direction of incident light by bending a cantilever provided with a mirror with an electrostatic force is also known.

  However, in the microactuator using the torsion hinge, since the mirror is held by the torsion hinge, it is easily broken by the torsional stress applied to the coupling portion of the torsion hinge, and it is difficult to extend its life. Also, in the microactuator using a cantilever, the response speed cannot be increased because the natural frequency of the cantilever is low.

  Therefore, in Patent Document 2 below, a micromirror device using a doubly supported beam provided to fix both ends on a substrate having a V-shaped recess and to span the recess is proposed. In this device, a light reflecting film is formed on both cantilever beams, and the mirror is integrated with the both cantilever beams as a whole. In the state where no electrostatic force is applied, the double-supported beam (that is, the mirror) has a flat plate shape. On the other hand, when the electrostatic force is applied, the double-supported beam (that is, the mirror) is V-shaped along the V-shaped recess by electrostatic force. To change the reflection direction of incident light.

Since this device uses a doubly-supported beam, it is less likely to break than using a torsion hinge, and it is possible to extend the service life, increase the natural frequency, and increase the response speed. Can be fast.
Japanese Patent No. 3492400 JP 2005-24966 A

  However, in the device disclosed in Patent Document 2, since the mirror is integrated with the doubly supported beam, when the doubly supported beam is deformed into a V shape by electrostatic force, the mirror is also deformed into a V shape, The reflection surface of the mirror becomes two surfaces (one surface of the V shape and the other surface) having different directions. As a result, the direction of the reflected light varies greatly depending on the position where the incident light is incident, stray light or the like is likely to be generated, and it is difficult to absorb light with respect to the stray light.

  Thus, although the device disclosed in Patent Document 2 is very excellent in terms of extending the life and speeding up the response speed, the driven mirror is integrated with the doubly supported beam. The mirror, which is a driven body, is also deformed, which causes inconvenience.

  Further, not only the microactuator used in the mirror device disclosed in Patent Document 2, but also the microactuator used in various other applications, the orientation of the driven body without deforming the driven body itself. May only be required to change.

  The present invention has been made in view of such circumstances, and can achieve a long life and a high response speed. In addition, only the direction of the driven body is changed without deforming the driven body itself. It is an object of the present invention to provide a microactuator that can be used. It is another object of the present invention to provide an optical device and a display device using such a microactuator.

  In order to solve the above-mentioned problem, a microactuator according to a first aspect of the present invention includes a base, a plate-like member supported by the base, and a driving force applying unit, and the plate-like member is the plate-like member. It is fixed to the base body at a predetermined location over the entire circumference or a part of the periphery of the member, and can be bent and deformed in a region other than the predetermined location in the plate-like member. The driven member is locally mechanically connected to a predetermined portion of the plate-like member in a region where the plate-like member can be bent and deformed, and includes the two portions facing each other in the peripheral portion of the plate-like member, Is driven on at least a part of the plate-like member so that the bending-deformable region of the plate-like member is deformed in accordance with a signal and the inclination of the predetermined portion of the plate-like member changes. It can give power.

  The plate-like member and / or the driven body may be formed of a thin film.

  The microactuator according to a second aspect of the present invention is the microactuator according to the first aspect, wherein the driven body has a main plane, and the main plane of the plate-like member and the main plane of the driven body are substantially parallel. There is something.

  The microactuator according to a third aspect of the present invention is the microactuator according to the first or second aspect, wherein the predetermined part of the plate-like member is a part eccentric from the center of gravity of the plate-like member.

  The microactuator according to a fourth aspect of the present invention is the microactuator according to any one of the first to third aspects, wherein the driving force applying means includes one or more first electrode portions provided on the base, One or more second electrode portions provided on a plate-like member and capable of generating an electrostatic force between the one or more first electrode portions due to a voltage between the one or more first electrode portions. Are included.

  The microactuator according to a fifth aspect of the present invention is the microactuator according to any one of the first to fourth aspects, wherein the driving force applying means bends the region where the bending deformation of the plate-shaped member is deformed according to a signal. A driving force is applied to at least a part of the plate-like member so that the predetermined portion of the plate-like member is displaced without deformation so that the inclination of the predetermined portion of the plate-like member is not substantially changed. To get.

  An optical device according to a sixth aspect of the present invention includes the microactuator according to any one of the first to fifth aspects and the driven body, and the driven body is an optical element.

  An optical device according to a seventh aspect of the present invention is the optical device according to the sixth aspect, wherein the optical element is a mirror.

  An optical device according to an eighth aspect of the present invention is the optical device according to the sixth or seventh aspect, comprising a plurality of sets of the microactuator and the optical element.

  A display device according to a ninth aspect of the present invention is a display device including a spatial light modulator, and the spatial light modulator is an optical device according to the eighth aspect.

  According to the present invention, it is possible to provide a microactuator that can achieve a long life and a high response speed and can change only the direction of the driven body without deforming the driven body itself. Can do. Further, according to the present invention, an optical device and a display device using such a microactuator can be provided.

  Hereinafter, a microactuator according to the present invention, an optical device using the same, and a display device will be described with reference to the drawings.

  [First Embodiment]

  FIG. 1 is a schematic perspective view schematically showing a unit element of the optical device according to the first embodiment of the present invention. FIG. 2 is a schematic plan view schematically showing the unit element shown in FIG. FIG. 3 is a schematic plan view schematically showing the plate-like member 2 of the unit element shown in FIG. FIG. 3 also shows a connecting portion 11 described later. FIG. 4 is a schematic cross-sectional view along the line A-A ′ in FIG. 2.

  For convenience of explanation, as shown in FIGS. 1 to 4, the X axis, the Y axis, and the Z axis that are orthogonal to each other are defined (the same applies to the drawings described later). The surface of the substrate 1 is parallel to the XY plane. 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 + side in the Z-axis direction may be referred to as the upper side, and the − side in the Z-axis direction may be referred to as the lower side. In addition, the material etc. which are demonstrated below are illustrations, and are not limited to this.

  The optical device according to the present embodiment includes a silicon substrate 1 as a base, a plate-like member 2 supported on the silicon substrate 1 via legs 3, a mirror 4 as an optical element as a driven body, and a fixed member. And an electrode (first electrode portion) 5. The driven body driven by the microactuator according to the present invention is not limited to the mirror 4, and may be other optical elements such as a diffractive optical element, an optical filter, a photonic crystal, or the like. Any member may be used.

  In the present embodiment, the plate-like member 2 has a quadrangular shape in plan view as seen from the Z-axis direction. When an electrostatic force described later as a driving force is not applied, the main plane of the plate-like member 2 is parallel to the XY plane as shown in FIGS.

  The plate-like member 2 is formed on an insulating film 6 such as a silicon oxide film on the substrate 1 in the vicinity of one side of the + X side and the one side of the −X side, which are two locations facing each other in the periphery of the plate-like member 2. It is fixed to the substrate 1 via legs 3 rising from the substrate 1 via a wiring pattern 7 made of an aluminum film (see FIG. 4 and omitted in FIGS. 1 and 2). Therefore, in this embodiment, the plate-like member 2 is a doubly supported beam. An area between the + X side leg 3 and the −X side leg 3 in the plate-like member 2 is an area that can be bent and deformed.

  The plate-like member 2 is composed of a thin film, and is composed of a three-layer film in which a silicon nitride film 8 as a lower insulating film, an intermediate aluminum film 9 and an upper silicon nitride film 10 are laminated.

  In the present embodiment, the leg portion 3 is configured by extending the silicon nitride films 8 and 10 and the aluminum film 9 constituting the plate-like member 2 as they are. The aluminum film 9 is connected to the wiring pattern 7 through an opening formed in the silicon nitride film 8 in the leg portion 3.

  In the present embodiment, the mirror 4 is composed of a thin film and is composed of an aluminum film. It has a quadrangular shape in plan view as viewed from the Z-axis direction. When the electrostatic force described later as the driving force is not applied, the main plane of the mirror 4 is parallel to the XY plane as shown in FIGS. 1 to 4, and the main plane of the plate-like member 2 is It is parallel. Although not shown in the drawing, in order to increase the rigidity of the mirror 4, it is preferable to reinforce by forming a step (a rising portion or a falling portion) around the mirror 4.

  The mirror 4 is mechanically locally connected to a portion that is eccentric in the −X direction from the center (center of gravity) of the plate-like member 2 in the region where the plate-like member 2 can be bent and deformed via the connection portion 11. It is connected. The connecting portion 11 is configured by extending an aluminum film constituting the mirror 4 as it is.

  In the present embodiment, the fixed electrode 5 is formed of an aluminum film so as to overlap the plate member 2 over the entire Y axis direction of the plate member 2 in the vicinity of the center of the plate member 2 in the X axis direction. ing. A movable electrode (second electrode portion) in which an area of the aluminum film 9 constituting the plate-like member 2 that faces the fixed electrode 5 can generate an electrostatic force with the fixed electrode 5 due to a voltage between the aluminum electrode 9 and the fixed electrode 5. ). The remaining region of the aluminum film 9 is a wiring pattern for connecting the movable electrode to the wiring pattern 7.

  In the present embodiment, as described above, the fixed portion of the mirror 4 with respect to the plate-like member 2 is eccentric in the −X direction, and the fixed electrode 5 and the movable electrode are at the center of the plate-like member 2 in the X-axis direction. Has been placed. In the present embodiment, this causes the fixed electrode 5 and the movable electrode to be deformed by deformation of the plate-like member 2 in accordance with a signal (in this embodiment, a voltage between the fixed electrode 5 and the movable electrode). A driving force that can apply a driving force (electrostatic force in the present embodiment) to the plate-like member 2 so that the possible region is deformed and the inclination of the fixed portion of the mirror 4 with respect to the plate-like member 2 changes. The giving means is configured. But in this invention, you may comprise a driving force provision means so that arbitrary driving forces other than an electrostatic force can be provided. For example, as the driving force applying means, a current path that is arranged in a magnetic field and generates a Lorentz force by energization may be provided in the plate-like member 2, or a piezoelectric element may be provided to use the driving force by the piezoelectric element.

  Here, the operation of the optical device according to the present embodiment (particularly, the operation of the unit element) will be described with reference to FIG. FIG. 5 is a diagram schematically showing each operation state of the optical device according to the present embodiment, and corresponds to a cross-sectional view that greatly simplifies FIG.

  In FIG. 5A, as in FIG. 4, no voltage is applied between the fixed electrode 5 and the movable electrode (a region of the aluminum film 9 facing the fixed electrode 5) (that is, both have the same potential). ), A state in which no electrostatic force is generated between them. In this state, the plate-like member 2 is not deformed and has a flat shape. For this reason, the mirror 4 is maintained parallel to the substrate 1.

  FIG. 5B shows a state where a not-so-high voltage is applied between the fixed electrode 5 and the movable electrode, and an electrostatic force is generated between them. By this electrostatic force, the vicinity of the center in the X-axis direction of the plate-like member 2 is pulled in the substrate direction (−Z direction). As a result, the deformable plate is bent toward the substrate 1 as shown in FIG. Since the fixing part of the mirror 4 with respect to the plate-like member 2 (that is, the part to which the connecting portion 11 is connected) is eccentric in the −X direction from the center of the plate-like member 2, the plate-like member 2 is positioned at the connecting portion 11. Make an inclined surface. By this action, the mirror 4 is inclined with respect to the substrate 1. The inclination angle can be adjusted by adjusting the voltage applied between the fixed electrode 5 and the movable electrode. In the present embodiment, DC driving in which a DC voltage is applied between both electrodes may be employed, or AC driving in which an AC pulse is applied to both electrodes may be employed. In order to avoid the influence of charge-up or the like, it is preferable to adopt AC driving.

  FIG. 5C shows a state in which a relatively high voltage is applied between the fixed electrode 5 and the movable electrode to generate a relatively large electrostatic force therebetween. In this state, the plate-like member 2 is deformed until it comes into contact with the substrate 1 and is stationary when it comes into contact. Also in this case, the mirror 4 is inclined with respect to the substrate 1 as in the case of FIG. 5B, but the inclination angle is larger than that in the case of FIG.

  Although the unit element of the optical device according to the present embodiment has been described above, the microactuator that drives the mirror 4 is configured by components other than the mirror 4 in the structure of the unit element described above.

  In the optical device according to the present embodiment, as shown in FIG. 6, the above-described unit elements shown in FIGS. 1 to 4 are two-dimensionally arranged on the substrate 1. Thereby, the optical device according to the present embodiment constitutes a spatial light modulator. In FIG. 6, for the sake of simplicity, 4 × 4 unit elements are arrayed, but any number of unit elements may be used. In FIG. 6, one mirror 4 corresponds to one unit element, but for simplicity, illustration of components other than the mirror 4 of each unit element is omitted. Note that the arrangement of unit elements is not limited to the example shown in FIG. 6, and for example, an arrangement such as shifting by half a pitch for each column or each row may be employed. Further, the unit elements may be arranged one-dimensionally. In FIG. 6, the mirror 4 in the second row and the second column is in the state shown in FIG. 5B, and the other mirrors 4 are in the state shown in FIG. In the present embodiment, the state shown in FIG. 5B is used without using the state shown in FIG. 5C. Conversely, the state shown in FIG. 5C is used. It may be.

  In the optical device according to the present embodiment, although not shown in the drawing, the voltage state between the electrodes of each unit element is determined so that the state of the mirror 4 of each unit element becomes a state corresponding to the control signal. A driving circuit is employed. As such a drive circuit, for example, a drive circuit similar to DMD or the like can be employed.

  Here, an example of the manufacturing method of the optical device according to the present embodiment will be described with reference to FIGS. 7 and 8 are cross-sectional views showing each manufacturing process and correspond to FIG.

  First, a silicon oxide film 6 is formed on a silicon substrate 1 on which a drive circuit is previously formed by a known semiconductor manufacturing process. Next, an aluminum film is formed, and the aluminum film is patterned into the shape of the fixed electrode 5 and the wiring pattern 7 by photolithography (FIG. 7A).

  Although not shown in FIG. 7A, the silicon oxide film 6 under the fixed electrode 5 and a part of the wiring pattern 7 is electrically connected to these aluminum films and the drive circuit. Drill holes as needed. Subsequently, a sacrificial layer 21 such as a photoresist is formed, and an opening 21a is formed by photolithography at a position where the leg 3 is to be formed in the sacrificial layer 21 (FIG. 7B).

  Thereafter, a silicon nitride film 8, an aluminum film 9, and a silicon nitride film 10 are sequentially formed, and these films 8 to 10 are patterned into the shape of the plate-like member 2 by a photolithography etching method (FIG. 7C). At this time, the etching step may be performed every time the film is formed, or after all the films have been formed, etching may be sequentially added from the upper layer film, or they may be combined. An opening is formed in the leg portion 3 in the silicon nitride film 8 so that the aluminum film 9 is electrically connected to the wiring pattern 7 in the leg portion 3.

  Next, a sacrificial layer 22 such as a photoresist is formed, and an opening 22a is formed in the sacrificial layer 22 at a position where the connection portion 11 is to be formed (FIG. 8A).

  Next, an aluminum film is formed, and this aluminum film is patterned into the shape of the mirror 4 by photolithography (FIG. 8B). Finally, the sacrificial layers 21 and 22 are removed. Thereby, the optical device according to the present embodiment is completed.

  According to the present embodiment, since the plate-like member 2 is a doubly-supported beam, as in the device disclosed in Patent Document 2 described above, damage is less likely to occur than when a torsion hinge is used. The lifetime can be increased, the natural frequency can be increased, and the response speed can be increased.

  And according to this Embodiment, unlike the device disclosed by patent document 2 mentioned above, the mirror 4 is not integrated with the plate-shaped member 2 entirely, but via the connection part 11, The plate-like member 2 is locally mechanically connected to a part of the region where the plate-like member 2 can be deformed. Therefore, as shown in FIG. 5 described above, only the orientation of the mirror 4 can be changed without deforming the mirror 4 itself.

  In the present invention, it is not always necessary to arrange a plurality of the above-described unit elements on the substrate 1, and only one unit element described above may be arranged on the substrate 1.

  [Second Embodiment]

  FIG. 9 is a schematic configuration diagram showing a projection display device (projection display device) according to the second embodiment of the present invention.

  The projection display device according to the present invention includes a light source 31, an illumination optical system 32, a spatial light modulator 33, a light absorption plate 34, a projection optical system 35, a screen 36, and a control unit 37. In the present embodiment, the optical device according to the first embodiment described above is used as the spatial light modulator 33.

  The illumination light emitted from the light source 31 passes through the illumination optical system 32 and is then applied to the spatial light modulator 33. Each unit element of the spatial light modulator 33 has its mirror 4 at the first angle (state shown in FIG. 5 (a)) or the second angle (state shown in FIG. 5 (b) or FIG. 5 (c)). Suppose you have At the first angle, the incident light is reflected in the first direction, reaches the light absorption plate 34, and the light disappears. At the second angle, incident light is reflected in the second direction, passes through the projection optical system 35, and is then projected onto the screen 36. The control unit 37 controls the spatial light modulator 33 by sending a control signal to the spatial light modulator 33 according to the image signal, and changes the angle of the mirror 4 of each unit element according to the image signal. With this control, a still image or a moving image indicated by the input image signal can be formed on the screen 36.

  Although this embodiment is an example of a so-called black and white display device, colorization can also be achieved by diverting the prior art. Although not shown, for example, a color wheel is installed in the illumination optical system 32 or between the illumination optical system 32 and the spatial light modulator 33, or the light source 31 is made up of red, blue, and green. It is assumed that the color can be controlled in time division, and colorization can be achieved by synchronizing with the spatial light modulator 33.

  The projection display device using the optical device according to the present invention is not limited to the type of display device as in the present embodiment, and can be used for various types of projection display devices. As a configuration example of the projection image display device, various types using a liquid crystal panel, DMD, or the like as a spatial light modulator have been proposed. Regarding the optical system used in the projection image display apparatus using DMD, the spatial light modulator by the optical device of the present invention is a mirror device that changes the mirror angle similar to that of DMD, and therefore basically the same one is used. Can be used. Projection image display devices using a liquid crystal panel use polarized light in principle, and there are transmission types as well as reflection types. For this reason, when these optical systems are adapted to the spatial light modulator by the optical device according to the present invention, it is sufficient to change those points.

  Note that the application using a spatial light modulator is not only a video application such as a projection image display device, but also an optical information processing device, an electrophotographic printing device, and one of semiconductor manufacturing devices described above. There are various uses such as an exposure apparatus, an optical switch used in optical communication, a switched-blazed grating device, and a plate setter used in the printing field. The present invention is also applicable to these.

  [Third Embodiment]

  FIG. 10 is a schematic plan view schematically showing the plate-like member 2 of the unit element of the optical device according to the third embodiment of the present invention, and corresponds to FIG. 10, elements that are the same as or correspond to those in FIG. 3 are given the same reference numerals, and redundant descriptions thereof are omitted.

  The optical device according to the present embodiment is different from the optical device according to the first embodiment in that, in the first embodiment, the plate-like member 2 is a substrate through the legs 3 only in the vicinity of the two sides. In the present embodiment, the plate member 2 is only fixed to the substrate 1 via the legs 3 in the vicinity of the four sides.

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

  [Fourth Embodiment]

  FIG. 11 is a schematic cross-sectional view schematically showing a unit element of an optical device according to the fourth embodiment of the present invention, and corresponds to FIG. 11, elements that are the same as or correspond to those in FIG. 4 are given the same reference numerals, and redundant descriptions thereof are omitted.

  The optical device according to the present embodiment is different from the optical device according to the first embodiment in that the connection portion 11 is arranged at the center of the mirror 4 and the connection portion 11 is at the center of the plate-like member 2. Instead of the fixed point and one fixed electrode 5 formed on the substrate 1 in the vicinity of the center of the plate member 2 in the X-axis direction, X is formed on the −X side and the −X side of the plate member 2. The point that two fixed electrodes 5a and 5b are formed on the substrate 1 at symmetrical positions with respect to the axial direction, and one aluminum film 9 that is continuous as a whole is composed of two aluminum films 9a on the −X side and the + X side. , 9b.

  In the present embodiment, the region 9a 'of the aluminum film 9a that faces the fixed electrode 5a is a movable electrode that can generate an electrostatic force between the fixed electrode 5a and the region 9a'. In addition, the region 9b 'of the aluminum film 9b facing the fixed electrode 5b is a movable electrode that can generate an electrostatic force with the fixed electrode 5b due to the voltage between the fixed electrode 5b.

  12 and 13 are diagrams schematically showing each operation state of the optical device according to the present embodiment, and correspond to a cross-sectional view that greatly simplifies FIG.

  FIG. 12A shows a state where no voltage is applied between the electrodes 5a and 9a 'and between the electrodes 5b and 9b', and no electrostatic force is generated between them, as in FIG. In this state, the plate-like member 2 is not deformed and has a flat shape. For this reason, the mirror 4 is maintained parallel to the substrate 1.

  In FIG. 12B, a relatively high voltage is applied between the electrodes 5a and 9a ′ to generate a relatively large electrostatic force therebetween, while no voltage is applied between the electrodes 5b and 9b ′. A state where no electrostatic force is generated is shown. In this state, the plate-like member 2 is in contact with the vicinity of the electrode 5a in the vicinity of the electrode 9a ', but the distance between the electrodes 5b and 9b' is relatively large. In this state, the mirror 4 is relatively large and tilted to the left in the drawing.

  In FIG. 12C, a relatively high voltage is applied between the electrodes 5b and 9b 'to generate a relatively large electrostatic force between them, while no voltage is applied between the electrodes 5a and 9a'. A state where no electrostatic force is generated is shown. In this state, the plate-like member 2 is in contact with the vicinity of the electrode 5b in the vicinity of the electrode 9b ', but the distance between the electrodes 5a and 9a' is relatively large. In this state, the mirror 4 is relatively large and tilted to the right side in the figure.

  In FIG. 13A, a not so high voltage is applied between the electrodes 5b and 9b ′ to generate an electrostatic force between them, while no voltage is applied between the electrodes 5a and 9a ′. The state which does not generate an electrostatic force is shown. In this state, the plate-like member 2 approaches the electrode 5b in the vicinity of the electrode 9b ', but the distance between the electrodes 5a and 9a' is relatively large. In this state, the mirror 4 is not so large and is inclined to the right side in the figure. The inclination angle can be adjusted by adjusting the voltage applied between the electrodes 5b and 9b '.

  Although not shown in the drawing, contrary to the case of FIG. 13A, a not so high voltage is applied between the electrodes 5a and 9a 'to generate an electrostatic force between them, while the electrodes 5b and 9b If no voltage is applied between them and no electrostatic force is generated between them, the plate-like member 2 approaches the electrode 5a near the electrode 9a ', but the distance between the electrodes 5b and 9b' is relatively large. Become. In this state, the mirror 4 is not so large and tilts to the left in the figure. The inclination angle can be adjusted by adjusting the voltage applied between the electrodes 5a and 9a '.

  FIG. 13B shows a state in which a relatively high voltage is applied between the electrodes 5a and 9a 'and between the electrodes 5b and 9b' to generate a relatively large electrostatic force therebetween. In this state, the plate-like member 2 is in contact with the vicinity of the electrode 5a in the vicinity of the electrode 9a 'and is in contact with the vicinity of the electrode 5b in the vicinity of the electrode 9b'. In this state, the mirror 4 is positioned at the lowest position while maintaining parallel to the substrate 1.

  FIG. 13C shows a state in which a not so high voltage is applied between the electrodes 5a and 9a 'and between the electrodes 5b and 9b' and a not so large electrostatic force is generated between them. In this state, the plate-like member 2 approaches the vicinity of the electrode 5a in the vicinity of the electrode 9a 'and approaches the vicinity of the electrode 5b in the vicinity of the electrode 9b'. In this state, the mirror 4 is located at an intermediate height position while maintaining parallel to the substrate 1. The height can be adjusted by adjusting the voltage applied between the electrodes 5a and 9a 'and between the electrodes 5b and 9b'.

  Thus, according to the present embodiment, as shown in FIGS. 12A to 12C and FIG. 13A, not only the inclination of the mirror 4 can be changed, but also FIG. As shown in FIGS. 13B and 13C, the height can be changed while the mirror 4 is kept parallel to the substrate 1.

  Therefore, according to the present embodiment, not only the direction of the reflected light can be changed, but also the optical distance of the reflected light is changed by changing the height position without tilting the mirror 4 to shift the phase of the reflected light. And can be used as a phase modulator.

  Except for this, the present embodiment can provide the same advantages as those of the first embodiment. When the optical device according to the present embodiment is used as the spatial light modulator 33 in FIG. 9, for example, the state shown in FIG. 12A is set at the first angle and the second angle is set. The state shown in FIG.

  In this embodiment, the fixed electrode 5a is replaced with the two fixed electrodes 5a and 5b and the aluminum film 9 is separated into the two aluminum films 9a ′ and 9b ′ at the same time. Even if only one of them is performed, the same effect as the present embodiment can be obtained.

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

It is a schematic perspective view which shows typically the unit element of the optical device by the 1st Embodiment of this invention. FIG. 2 is a schematic plan view schematically showing the unit element shown in FIG. 1. It is a schematic plan view which shows typically the plate-shaped member of the unit element shown in FIG. FIG. 3 is a schematic cross-sectional view along the line A-A ′ in FIG. 2. It is a figure which shows typically each operation state of the optical device by the 1st Embodiment of this invention. It is a figure which shows the example of arrangement | positioning of the unit pixel in the optical device by the 1st Embodiment of this invention. It is process drawing which shows the manufacturing method of the optical device by the 1st Embodiment of this invention. FIG. 8 is a process diagram illustrating a process following the process in FIG. 7. It is a schematic block diagram which shows the projection display apparatus by the 2nd Embodiment of this invention. It is a schematic plan view which shows typically the plate-shaped member of the unit element of the optical device by the 3rd Embodiment of this invention. It is a schematic sectional drawing which shows typically the unit element of the optical device by the 4th Embodiment of this invention. It is a figure which shows typically each operation state of the optical device by the 4th Embodiment of this invention. It is a figure which shows typically each other operation state of the optical device by the 4th Embodiment of this invention.

Explanation of symbols

1 substrate 2 plate-like member 4 mirror 5 fixed electrode

Claims (9)

A base, a plate-like member supported by the base, and a driving force applying means;
The plate-like member is fixed to the base at a predetermined location over the entire circumference or a part of the periphery of the plate-like member, and can be bent and deformed in a region other than the predetermined location in the plate-like member. Yes,
The predetermined location includes two locations facing each other in the peripheral portion of the plate-shaped member,
A driven body is locally mechanically connected to a predetermined portion of the plate-shaped member in a deformable region;
In response to the signal, the driving force applying means is configured so that the region of the plate-like member that can be bent and deformed is bent and the inclination of the predetermined portion of the plate-like member is changed. A driving force can be applied to at least a part,
A microactuator characterized by that.   2. The microactuator according to claim 1, wherein the driven body has a main plane, and the main plane of the plate member and the main plane of the driven body are substantially parallel.   3. The microactuator according to claim 1, wherein the predetermined portion of the plate-like member is a portion decentered from the center of gravity of the plate-like member.   The driving force applying means may be configured such that the one or more first electrode portions provided on the base and the one or more first electrode portions provided on the plate-like member by a voltage between them. The microactuator according to any one of claims 1 to 3, further comprising one or more second electrode portions capable of generating an electrostatic force between the first electrode portion and the first electrode portion.   In response to the signal, the driving force applying means deforms the deformable region of the plate-like member so that the inclination of the predetermined portion of the plate-like member does not substantially change, and the plate-like member The microactuator according to any one of claims 1 to 4, wherein a driving force can be applied to at least a part of the plate-like member so that the predetermined portion of the member is displaced.   An optical device comprising the microactuator according to any one of claims 1 to 5 and the driven body, wherein the driven body is an optical element.   The optical device according to claim 6, wherein the optical element is a mirror.   The optical device according to claim 6 or 7, comprising a plurality of sets of the microactuator and the optical element.   A display device comprising a spatial light modulator, wherein the spatial light modulator is the optical device according to claim 8.

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