JP2022146675A - Movable device, deflection device, object recognition device, image projection device, and mobile object - Google Patents

Abstract

To provide a movable device capable of suppressing the changes in scanning angle and scanning center of a reflector due to gravity.SOLUTION: A movable device disclosed herein comprises a movable portion capable of rotating about a given axis, and a drive portion having one end thereof connected to the movable portion to rotate the movable portion, the movable portion having an extended part extending in the direction of the given axis.SELECTED DRAWING: Figure 1

Description

The present invention relates to a movable device, a deflection device, an object recognition device, an image projection device, and a moving body.

2. Description of the Related Art In recent years, with the development of micromachining technology applying semiconductor manufacturing technology, development of MEMS (Micro Electro Mechanical Systems) devices manufactured by microfabrication of silicon or glass is progressing.

The MEMS device includes, for example, a movable portion having a reflecting portion, a first driving portion connected to the movable portion to drive the movable portion, and a first support connected to the first driving portion to support the first driving portion. A movable device having a portion and a is known. In this movable device, the movable section includes adjusting sections arranged symmetrically with respect to the reflecting section (see, for example, Patent Literature 1).

In this movable device, the adjustment part is a part that ensures the symmetry of the weight of the movable part. and ensure the stability of the rotation of the movable part.

By the way, in the movable device described above, the reflection section changes its position and installation direction in the Z direction (gravitational direction) under the influence of gravity. This changes the scanning angle and scanning center of the reflector. If the scanning angle and the scanning center of the reflector change, for example, when the movable device is applied to sensing technology for measuring the distance to an object, the accuracy of measurement results may be deteriorated. However, in the movable device described above, there is room for improvement in terms of changes in the scanning angle of the reflecting section and changes in the scanning center due to the influence of gravity.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a movable device capable of suppressing changes in the scanning angle and scanning center of the reflecting section due to the influence of gravity.

A movable device according to an aspect of technology disclosed herein includes a movable portion rotatable about a predetermined axis, and a driving portion having one end connected to the movable portion and rotating the movable portion, the The movable part has an extending part extending in the direction in which the predetermined axis extends.

According to the technology disclosed herein, it is possible to provide a movable device capable of suppressing changes in the scanning angle of the reflecting section and changes in the scanning center due to the influence of gravity.

It is a top view (view seen from the reflective surface side) of the optical deflector which is a movable device which concerns on 1st Embodiment. FIG. 2 is a bottom view of the optical deflector, which is the movable device according to the first embodiment (viewed from the side opposite to the reflecting surface). FIG. 2 is a cross-sectional view taken along line AA of FIG. 1; FIG. 2 is a cross-sectional view taken along line BB of FIG. 1; FIG. 3 is a partial bottom view of the optical deflector, which is the movable device according to the first embodiment (viewed from the side opposite to the reflecting surface). FIG. 6 is a cross-sectional view taken along line CC of FIG. 5; It is a top view (a figure seen from the reflective surface side) of an optical deflector which is a movable device concerning modification 1 of a 1st embodiment. It is a top view (view seen from the reflective surface side) of the optical deflector which is a movable apparatus based on the modified example 2 of 1st Embodiment. FIG. 11 is a plan view (viewed from the reflective surface side) of an optical deflector that is a movable device according to Modification 3 of the first embodiment; It is a top view (a figure seen from the reflective surface side) of an optical deflector which is a movable device concerning a 2nd embodiment. It is a bottom view (viewed from the side opposite to the reflective surface) of the optical deflector, which is the movable device according to the second embodiment. It is a top view (view seen from the reflective surface side) of the optical deflector which is a movable apparatus based on the modified example 1 of 2nd Embodiment. It is a top view (a figure seen from the reflective surface side) of an optical deflector which is a movable device concerning a 3rd embodiment. It is a top view (a figure seen from the reflective surface side) of an optical deflector which is a movable device concerning modification 1 of a 3rd embodiment. 1 is a schematic diagram of an example optical scanning system; FIG. 1 is a hardware configuration diagram of an example of an optical scanning system; FIG. It is a functional block diagram of an example of a drive. 4 is a flowchart of an example of processing related to an optical scanning system; 1 is a schematic diagram of an example of a vehicle equipped with a head-up display device; FIG. 1 is a schematic diagram of an example of a head-up display device; FIG. 1 is a schematic diagram of an example of an image forming apparatus equipped with an optical writing device; FIG. 1 is a schematic diagram of an example of an optical writing device; FIG. 1 is a schematic diagram of an example of an automobile equipped with a laser radar device; FIG. 1 is a schematic diagram of an example of a laser radar device; FIG. 1 is a schematic diagram of an example of a packaged optical deflector; FIG.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments for carrying out the invention will be described with reference to the drawings. In each drawing, the same components are denoted by the same reference numerals, and redundant description may be omitted.

In the following description of the embodiments, the terms rotation, swing, and movement are synonymous. Furthermore, among the directions indicated by the arrows, the X direction is the direction parallel to the first axis, which is the rotation axis, the Y direction is the direction perpendicular to the first axis, and the Z direction is the direction perpendicular to the XY plane.

<First Embodiment>
FIG. 1 is a plan view (viewed from the reflective surface side) of an optical deflector, which is a movable device according to the first embodiment. FIG. 2 is a bottom view of the optical deflector, which is the movable device according to the first embodiment (viewed from the side opposite to the reflecting surface). FIG. 3 is a cross-sectional view along line AA of FIG. FIG. 4 is a cross-sectional view along line BB of FIG.

Referring to FIGS. 1-4, the movable device 100 is a double-ended optical deflector. The movable device 100 mainly has a movable portion 101, a reflecting portion 102, driving portions 103a and 103b, and supporting portions 104a and 104b. The movable device 100 has a structure that enables a movable portion 101 including a reflecting portion 102 to rotate about a first axis AX1 parallel to the X axis. That is, the movable device 100 can deflect incident light while scanning in one axial direction by rotating the movable portion 101 including the reflecting portion 102 in one axial direction (around the first axis AX1). The structure of the mobile device 100 will be described in detail below.

The movable portion 101 has a central portion 101a and extension portions 101b and 101c. The central portion 101a has, for example, a rectangular shape whose length in the Y direction is longer than the length in the X direction, and is arranged so as to straddle the first axis AX1.

The extending portion 101b extends in the direction in which the first axis AX1 extends from both sides of the +Y side end portion (one end portion in the direction orthogonal to the first axis AX1) of the central portion 101a. The extending portion 101c extends in the direction in which the first axis AX1 extends from both sides of the -Y side end portion (the other end portion in the direction orthogonal to the first axis AX1) of the central portion 101a. The extensions 101b and 101c are, for example, rectangular with a length in the X direction longer than the length in the Y direction. In the example of FIG. 1, the extensions 101b and 101c have a constant width. However, not limited to this, the extensions 101b and 101c may have partially different widths.

Here, "extending in the direction in which the first axis AX1 extends" means that the object extends in a direction other than the direction perpendicular to the first axis AX1. That is, the extending portions 101b and 101c need only extend in a direction other than the direction perpendicular to the first axis AX1, and may be inclined with respect to the first axis AX1. However, from the viewpoint of suppressing an increase in the size of the movable device 100, as shown in FIG. 1, the extensions 101b and 101c preferably have longitudinal directions parallel to the first axis AX1.

In the present application, "parallel" includes cases where two straight lines, sides, etc. are in the range of 0°±5°. Also, "perpendicular" or "perpendicular" includes cases where two straight lines, sides, etc. are in the range of 90°±5°. However, this does not apply if there is a special explanation individually. Also, "center" and "center" indicate the approximate center or center of an object, and do not indicate the exact center or center. In other words, variations on the order of manufacturing errors are allowed. The same applies to point symmetry, line symmetry, and the like.

Reflecting portion 102 is formed on movable portion 101 . Specifically, the reflecting portion 102 is provided on most of the surface on the +Z side of the central portion 101a. The reflecting portion 102 may be formed on part or all of the extending portions 101b and 101c. Reflector 102 is rectangular in the example of FIG. 1, but may be circular, elliptical, or other complex shape. The reflecting section 102 is composed of, for example, a metal thin film containing aluminum, gold, silver, or the like, or a multilayer film thereof. The reflecting surface 102a is the surface of the reflecting section 102 on the +Z side.

One end of the drive units 103a and 103b is directly or indirectly connected to the movable unit 101, and rotates the movable unit 101. As shown in FIG. That is, the driving units 103a and 103b are a pair of actuators that rotatably support the movable unit 101 including the reflecting unit 102. As shown in FIG. The drive portions 103a and 103b have a plurality of beam portions 115 serving as vibrating beams and a connecting portion 116 connecting adjacent beam portions 115 to each other. In the driving portions 103a and 103b, adjacent beam portions 115 are alternately connected on the +Y side and the -Y side by connecting portions 116 to form a meander structure. Note that the connecting portion 116 may not connect the longitudinal ends of the adjacent beams 115 to each other, but may connect the portions closer to the longitudinal ends of the adjacent beams 115 to each other.

The +X side and -Y side end portions of the drive portion 103a are connected to the central portion 101a of the movable portion 101 via the movable portion connection portion 117a. The -X side and -Y side end portions of the drive portion 103a are connected to the support portion 104a via the support portion connection portion 118a. In addition, the −X side and +Y side end portions of the driving portion 103b are connected to the central portion 101a of the movable portion 101 via the movable portion connecting portion 117b. The +X side and +Y side end portions of the drive portion 103b are connected to the support portion 104b via the support portion connection portion 118b. In addition, in the example of FIG. 1, the support portions 104a and 104b are arranged on both sides of the movable portion 101 in the X direction. The supporting portion 104a supports the driving portion 103a, and the supporting portion 104b supports the driving portion 103b.

Drive element groups 119a and drive element groups 119b are alternately provided for each beam 115 on the +Z side surface of the beam 115 positioned on the −X side of the central portion 101a. Similarly, drive element groups 119a and drive element groups 119b are alternately provided for each beam 115 on the +Z side surface of the beam 115 positioned on the +X side of the central portion 101a. The drive element groups 119a and 119b are, for example, piezoelectric elements.

The movable device 100 can be formed point-symmetrically with respect to the center of the movable part 101, for example. However, without being limited to this, the movable device 100 may be formed line-symmetrically with respect to a straight line that is perpendicular to the first axis AX1 and passes through the center of the movable portion 101, for example.

For example, the movable device 100 is formed by forming one SOI (Silicon On Insulator) substrate by etching processing or the like, and forming the reflection section 102 and the driving element groups 119a and 119b on the formed substrate, thereby forming each component. are integrally formed. An SOI substrate is a substrate in which a silicon oxide layer is provided on a silicon support layer made of single crystal silicon (Si), and a silicon active layer made of single crystal silicon is further provided on the silicon oxide layer.

Since the thickness of the silicon active layer in the Z direction is smaller than that in the X or Y direction, the member composed only of the silicon active layer functions as an elastic part having elasticity. The thickness of the silicon active layer is, for example, about 20-60 μm. Note that the SOI substrate does not necessarily have to be planar, and may have a curvature or the like.

A central portion 101a of the movable portion 101 is formed of, for example, a silicon active layer, and a reflecting portion 102 is formed on the +Z side surface of the silicon active layer. The extending portions 101b and 101c of the movable portion 101 are also formed of, for example, a silicon active layer, like the central portion 101a.

As shown in FIG. 4, the support portion 104a is formed of, for example, a silicon support layer 131, a silicon oxide layer 132, and a silicon active layer 133 which are sequentially laminated. The same applies to the support portion 104b. The beam 115 is made of, for example, a silicon active layer.

Each of the drive element groups 119a and 119b is a piezoelectric element, and has, for example, a lower electrode 135, a piezoelectric section 136, and an upper electrode 137 which are sequentially formed on the +Z side surface of the beam section 115. FIG. The lower electrode 135 and the upper electrode 137 can be formed by sputtering using, for example, gold (Au) or platinum (Pt). The piezoelectric section 136 can be made of, for example, PZT (lead zirconate titanate), which is a piezoelectric material, but may be made of other piezoelectric materials, regardless of the type. The thickness of the piezoelectric portion 136 is, for example, about 2 μm.

When a voltage signal is applied between the lower electrodes 135 and upper electrodes 137 of the driving element groups 119a and 119b, the movable portion 101 including the reflecting portion 102 rotates around the first axis AX1. Specifically, in the driving element groups 119a and 119b, the odd-numbered beam portions 115 and the even-numbered beam portions 115 are alternately driven in reverse phase from the supporting portions 104a and 104b, respectively.

For example, when a pulse wave or sine wave voltage signal is applied between the lower electrode 135 and the upper electrode 137, the driving element groups 119a and 119b expand and contract in the in-plane direction of the surface of the beam portion 115 due to their electrostrictive characteristics. repeat. As a result, the beam portion 115 bends and vibrates, the meandering structure alternately moves up and down, and the vertical motion of the meandering structure is converted into rotational vibration (torsional vibration). rotate around.

1, the driving element groups 119a and 119b are provided on a part of the beam portion 115. As shown in FIG. However, the driving element groups 119a and 119b do not necessarily have to be provided on a part of the beam portion 115, and may be provided on the entire surface of the beam portion 115. FIG. Further, the driving element groups 119 a and 119 b need not be provided on all the beams 115 , and may be provided only on some of the plurality of beams 115 .

An insulating layer made of a silicon oxide layer or the like may be formed on at least one of the +Z side surface of the upper electrode 137 and the +Z side surfaces of the support portions 104a and 104b. At this time, the electrode wiring is provided on the insulating layer, and only the connection spots where the lower electrode 135 or the upper electrode 137 and the electrode wiring are connected are partially removed or not formed as openings. is preferred. As a result, the degree of freedom in designing the driving units 103a and 103b and the electrode wiring can be improved, and short circuits due to contact between the electrodes can be suppressed. The silicon oxide layer may also function as an antireflection material.

Further, the driving element groups 119a and 119b may have a structure in which a plurality of piezoelectric portions are laminated and an intermediate electrode is included.

In addition, although the example which forms the mobile device 100 from the SOI substrate was shown above, it does not restrict to this. The movable device 100 may be formed from a substrate other than the SOI substrate as long as it can be integrally formed by etching or the like and can be partially elastic. Examples of such substrates include Si substrates and Al substrates.

Thus, in the movable device 100, the movable portion 101 has extension portions 101b and 101c extending in the direction of the first axis AX1. This makes it possible to suppress the change in the scanning angle and the change in the scanning center (displacement in the -Z direction) of the reflector 102 due to the influence of gravity. As a result, the movable device 100 can perform highly accurate optical scanning. This will be explained in more detail below.

One of the causes of the change in the scanning angle and the change in the scanning center of the reflecting section 102 due to the influence of gravity is that the reflecting section 102 is displaced in the -Z direction (gravitational direction) under the influence of gravity. The displacement in the −Z direction due to the effect of gravity of the reflecting section 102 is proportional to (mass)/(spring constant) of the movable section 101 including the reflecting section 102 . On the other hand, the change in the resonance frequency of the movable part 101 is proportional to the square root of (torsional spring constant about the first axis AX1)/(moment of inertia about the first axis AX1) of the movable part 101 including the reflecting part 102. .

Here, the spring constant and the torsional spring constant about the first axis AX1 are approximately proportional. Therefore, the change in the scanning angle and the change in the scanning center of the reflector 102 due to the influence of gravity are proportional to (mass)/(inertia moment about the first axis AX1). Therefore, in order to suppress the change in the scanning angle and the change in the scanning center of the reflection section 102 due to the influence of gravity, it is sufficient to reduce (mass)/(inertia moment about the first axis AX1).

Generally, in the movable part 101, the moment of inertia of the movable part 101 around the first axis AX1 increases as the mass of the part farther from the first axis AX1 increases. Therefore, in the movable part 101, if the mass is concentrated in a region distant from the first axis AX1, (mass)/(inertia moment about the first axis AX1) can be reduced, and the scanning of the reflecting part 102 due to the influence of gravity can be reduced. Angle changes and scanning center changes can be effectively suppressed.

That is, in the movable device 100, the movable portion 101 has the extending portions 101b and 101c extending in the direction of the first axis AX1, thereby increasing the moment of inertia of the movable portion 101 around the first axis AX1. As a result, (mass)/(moment of inertia about the first axis AX1) can be reduced in the movable portion 101, and changes in the scanning angle and scanning center of the reflecting portion 102 due to the influence of gravity can be suppressed. The movable portion 101 preferably has a symmetrical planar shape and mass with respect to the first axis AX1. Thereby, the moment of inertia of the movable portion 101 about the first axis AX1 can be increased more efficiently.

Note that the resonance frequency of the movable portion 101 is proportional to the square root of (torsional spring constant about the first axis AX1)/(moment of inertia about the first axis AX1). As the surrounding moment of inertia increases, the resonance frequency of the movable part 101 decreases. In order to maintain the resonance frequency of the movable part 101, the spring constant of the movable part 101 needs to be increased. It is possible to further suppress the change and the change of the scanning center.

Although the same effect as described above can be obtained by increasing the length of the movable portion in the direction perpendicular to the first axis AX1, the size of the movable device increases and the cost also increases, which is not preferable. In the movable device 100 according to this embodiment, the extending portions 101b and 101c of the movable portion 101 extend in the direction in which the first axis AX1 extends, and do not extend in the direction orthogonal to the first axis AX1. As a result, it is possible to increase the moment of inertia of the movable unit 101 around the first axis AX1 while suppressing an increase in the size of the mobile device 100, which is advantageous in terms of suppressing the size of the mobile device 100 and reducing costs. is.

In FIG. 1, the −X side end of the extending portion 101b is preferably positioned further in the +X direction than the most +X side position of the +Y side end of the supporting portion 104a. Also, the +X side end of the extending portion 101b is preferably positioned further in the -X direction than the most -X side position of the +Y side end of the support portion 104b. Moreover, it is preferable that the -X side end of the extending portion 101c is positioned further in the +X direction than the most +X side position of the -Y side end of the support portion 104a. Moreover, it is preferable that the +X side end of the extending portion 101c is located further in the -X direction than the most -X side position of the -Y side end of the support portion 104b.

In other words, the X-direction length of the extending portion 101b is preferably shorter than the X-direction length of the region sandwiched between the supporting portions 104a and 104b facing each other. In addition, it is preferable that the length in the X direction of the extending portion 101c is shorter than the length in the X direction of the region sandwiched between the supporting portions 104a and 104b facing each other. By satisfying these requirements, it is possible to reduce the possibility that the extending portions 101b and 101c will come into contact with the supporting portions 104a and 104b when the movable portion 101 rotates.

FIG. 5 is a partial bottom view of the optical deflector, which is the movable device according to the first embodiment (viewed from the side opposite to the reflecting surface). 6 is a cross-sectional view taken along line CC of FIG. 5. FIG.

As shown in FIGS. 5 and 6, the movable portion 101 may have a projecting portion 108 (rib structure) projecting on one side in the thickness direction. Specifically, the movable portion 101 may have a protrusion 108 on the back side (surface on the −Z side). The protrusion 108 is composed of, for example, a silicon support layer 131 and a silicon oxide layer 132 which are sequentially laminated. A movable portion 101 formed of a silicon active layer is located on the silicon oxide layer 132 .

The protrusions 108 can be provided, for example, on the +Y side end of the central portion 101a and the back side of the extension portion 101b, and the −Y side end of the center portion 101a and the back side of the extension portion 101c. The protruding portion 108 may be provided on the back side of the other region of the central portion 101a, that is, the region that mainly overlaps with the reflecting portion 102 in plan view. The projecting portion 108 may be provided only on the rear surface side of the extending portion 101b and the extending portion 101c. The protrusion 108 is preferably provided symmetrically with respect to the first axis AX1.

It should be noted that planar view means viewing from the normal direction of the +Z side surface of the movable portion 101 when the movable portion 101 is not rotating. Further, when the movable portion 101 is not rotating, the shape viewed from the normal direction of the +Z side surface of the movable portion 101 may be referred to as a planar shape.

By providing the projection 108 on the back side of the movable portion 101 in this way, the moment of inertia of the movable portion 101 about the first axis AX1 can be increased more than in the case of FIGS. As a result, (mass)/(moment of inertia about the first axis AX1) in the movable part 101 can be made even smaller than in the case of FIGS. A change in the scanning center can be further suppressed than in the case of FIGS. 1 to 4. FIG.

In order to effectively increase the moment of inertia of the movable portion 101 about the first axis AX1, it is preferable to preferentially provide the projecting portion 108 from a region away from the first axis AX1. However, as shown in FIG. 5, providing the protrusion 108 also on the rear surface side of the reflecting section 102 is preferable in that deformation of the reflecting section 102 during rotation can be reduced. In addition, since the moment of inertia is affected by the mass other than on the first axis AX1, providing the projection 108 on the back side of the reflecting part 102 also has a certain effect in improving the moment of inertia.

FIG. 7 is a plan view (viewed from the reflective surface side) of an optical deflector that is a movable device according to Modification 1 of the first embodiment. As in the movable device 100A shown in FIG. 7, in a plan view, the movable portion 101 includes driving portions 103a and 103b at the ends on the -X side and the +X side, which are the ends in the longitudinal direction of the extending portion 101b. may have a projecting portion 101d projecting to the opposite side. In a plan view, the movable portion 101 has projections 101e projecting from the -X side end and the +X side end, which are the longitudinal ends of the extension portion 101c, in the opposite direction to the drive portions 103a and 103b. may be provided.

By providing the protruding portions 101d and 101e, the mass of the region away from the first axis AX1 can be effectively increased, so that the moment of inertia of the movable portion 101 about the first axis AX1 is increased more than in the case of FIGS. can be increased. As a result, (mass)/(moment of inertia about the first axis AX1) in the movable part 101 can be made even smaller than in the case of FIGS. A change in the scanning center can be further suppressed than in the case of FIGS. 1 to 4. FIG. In 100 A of mobile devices, the projection part 108 shown in FIG.5 and FIG.6 may further be provided.

FIG. 8 is a plan view (viewed from the reflective surface side) of an optical deflector that is a movable device according to Modification 2 of the first embodiment. Like the movable device 100B shown in FIG. 8, in a plan view, the movable part 101 has driving parts 103a and 103b at the -X side end and the +X side end, which are the ends in the longitudinal direction of the extension part 101b. A protruding portion 101f protruding to the side may be provided. Further, in a plan view, the movable portion 101 is provided with projecting portions 101g projecting toward the driving portions 103a and 103b at the ends on the -X side and the +X side, which are the ends in the longitudinal direction of the extending portion 101c. may

By providing the protruding portions 101f and 101g, the mass of the region away from the first axis AX1 can be effectively increased, so that the moment of inertia of the movable portion 101 about the first axis AX1 is increased more than in the case of FIGS. can be increased. As a result, (mass)/(moment of inertia about the first axis AX1) in the movable part 101 can be made even smaller than in the case of FIGS. A change in the scanning center can be further suppressed than in the case of FIGS. 1 to 4. FIG.

Comparing the movable device 100A and the movable device 100B, the movable device 100A is preferable in that the projecting portion is less likely to come into contact with the supporting portion, and the movable device 100B is preferable in that the overall size can be reduced.

In addition, in the movable device 100B, the projecting portion 108 shown in FIGS. 5 and 6 may be further provided. Moreover, in the mobile device 100B, the structure of the mobile device 100A may be additionally employed. That is, in the movable device 100B, in addition to the protrusions 101f and 101g, protrusions 101d and 101e that protrude on the side opposite to the drive sections 103a and 103b in plan view may be provided.

FIG. 9 is a plan view (viewed from the reflective surface side) of an optical deflector that is a movable device according to Modification 3 of the first embodiment. As in a movable device 100C shown in FIG. 9, a reflecting portion 102 may be provided on the entire surface on the +Z side of the central portion 101a and the extending portions 101b and 101c. As a result, the mass of the area apart from the first axis AX1 in the movable part 101 can be increased, so that the moment of inertia of the movable part 101 around the first axis AX1 can be increased more than in the case of FIGS. 1 to 4. .

As a result, (mass)/(moment of inertia about the first axis AX1) in the movable part 101 can be made even smaller than in the case of FIGS. A change in the scanning center can be further suppressed than in the case of FIGS. 1 to 4. FIG. In 100 C of mobile devices, the projection part 108 shown in FIG.5 and FIG.6 may further be provided. Moreover, in 100 C of movable apparatuses, you may further provide the protrusion part shown in FIG. 7 or FIG.

Note that the reflecting portion 102 does not necessarily have to be provided on the entire surface on the +Z side of the center portion 101a and the extension portions 101b and 101c. It is effective in that the moment of inertia around it can be increased. In addition, when the reflecting portion 102 is provided on the entire surface of the +Z side of the center portion 101a and the extension portions 101b and 101c, the thickness of the movable portion 101 is made uniform, thereby suppressing the generation of unnecessary vibration modes. But preferred.

Note that the reflective portion 102 may be provided only in a region necessary for reflecting light, and a layer made of a material different from that of the reflective portion 102 may be provided in other regions to improve the mass. In this case as well, the moment of inertia of the movable portion 101 around the first axis AX1 can be increased.

<Second embodiment>
FIG. 10 is a plan view (viewed from the reflecting surface side) of an optical deflector, which is a movable device according to the second embodiment. FIG. 11 is a bottom view (viewed from the side opposite to the reflecting surface) of the optical deflector, which is the movable device according to the second embodiment.

10 and 11, the movable device 200 is an optical deflector with a double-end support structure. The movable device 200 has a structure that enables a movable portion 201 including a reflecting portion 202 to rotate around a first axis AX1 parallel to the X axis. That is, the movable device 200 can deflect incident light while scanning in one axial direction by rotating the movable portion 201 including the reflecting portion 202 in one axial direction (around the first axis AX1). The structure of the mobile device 200 will be described in detail below.

The movable device 200 mainly has a movable portion 201, a reflecting portion 202, driving portions 203a and 203b, a supporting portion 204, and a pair of torsion beams 220a and 220b. The movable device 200 can be formed point-symmetrically with respect to the center of the movable part 201, for example.

The movable portion 201 has a central portion 201a and extension portions 201b and 201c. The central portion 201a has, for example, a rectangular shape whose length in the Y direction is longer than the length in the X direction. The extending portions 201b extend in the direction in which the first axis AX1 extends from both sides of the +Y side end portion of the central portion 201a. The extending portions 201c extend in the direction in which the first axis AX1 extends from both sides of the -Y side end portion of the central portion 201a. The extensions 201b and 201c are, for example, rectangular with a length in the X direction longer than the length in the Y direction.

In the example of FIG. 10, the extensions 201b and 201c are parallel to the first axis AX1. However, the extending portions 201b and 201c may be inclined with respect to the first axis AX1. Also, in the example of FIG. 10, the extensions 201b and 201c have a constant width. However, not limited to this, the extensions 201b and 201c may have partially different widths.

Reflecting portion 202 is formed on movable portion 201 . Specifically, the reflecting portion 202 is formed on most of the surface on the +Z side of the central portion 201a. The reflecting portion 202 may be formed on part or all of the extending portions 201b and 201c. Reflector 202 is rectangular in the example of FIG. 10, but may be circular, elliptical, or other complex shape. The reflecting section 202 is composed of, for example, a metal thin film containing aluminum, gold, silver, or the like, or a multilayer film thereof. The reflecting surface 202a is the surface of the reflecting section 202 on the +Z side.

The driving units 203a and 203b are a pair of actuators that rotatably support the movable unit 201 including the reflecting unit 202. As shown in FIG. Each of the driving portions 203a and 203b has a beam portion 215 serving as a vibrating beam, and driving elements 219a and 219b formed on the upper surface of the beam portion 215. As shown in FIG.

The beam portion 215 is arranged with its longitudinal direction directed in the Y direction, and both ends thereof are connected to the inside of the support portion 204 . The drive elements 219a and 219b are formed in a strip shape with the longitudinal direction directed in the Y direction. The driving elements 219a and 219b are arranged, for example, so as to be line-symmetrical with respect to the first axis AX1. The drive elements 219a and 219b are, for example, piezoelectric elements.

The support portion 204 is formed, for example, in a rectangular frame shape so as to surround the movable portion 201 . The support part 204 is composed of, for example, a silicon support layer, a silicon oxide layer, and a silicon active layer. Note that the support section 204 does not have to be formed so as to completely surround the movable section 201. For example, the support sections 104a and 104b in FIG. 1 can be separately arranged.

Each of the torsion beams 220a and 220b has one end connected to a substantially central portion in the longitudinal direction of the central portion 201a of the movable portion 201, and extends in the direction of the first axis AX1. The torsion beams 220a and 220b are a pair of elastic support portions that support the movable portion 201 including the reflecting portion 202 so as to be movable around the first axis AX1. Torsion beams 220a and 220b are composed of, for example, a silicon active layer.

The other end of the torsion beam 220a is connected to a substantially central portion in the longitudinal direction of the beam portion 215 of the driving portion 203a. The other end of the torsion beam 220b is connected to a substantially central portion in the longitudinal direction of the beam portion 215 of the driving portion 203b. The longitudinal direction of the torsion beams 220a and 220b and the longitudinal direction of the beam portion 215 are perpendicular. The central axis of the torsion beam 220a is, for example, the first axis AX1.

Thus, the beam portions 215 of each of the driving portions 203a and 203b are arranged on both sides in the Y direction with respect to the first axis AX1, which is the central axis of the torsion beam 220a. The beam portion 215 supports the movable portion 201 including the reflecting portion 202 and the torsion beams 220a and 220b from both sides of the supporting portion 204. As shown in FIG.

In mobile device 200, drive elements 219a and 219b have, for example, the same structure as drive element groups 119a and 119b. In the movable device 200, for example, when a pulse wave or sine wave voltage signal is applied between the lower electrodes and the upper electrodes of the driving elements 219a and 219b, the driving elements 219a and 219b move the beam 215 due to their electrostrictive characteristics. Repeated expansion and contraction in the in-plane direction of the surface. The bending vibration of the beam portion 215 is converted into rotational vibration (torsional vibration) by the torsion beams 220a and 220b, and the movable portion 201 including the reflecting portion 202 rotates around the first axis AX1.

The movable device 200 can be formed using, for example, an SOI substrate, a Si substrate, an Al substrate, or the like, like the movable device 100 .

As long as the movable portion 201 including the reflecting portion 202 can be driven around the first axis AX1, the shape of each constituent portion is not limited to the shape of the embodiment. For example, torsion beams 220a and 220b and beam portion 215 may have a curved shape.

Thus, in the movable device 200, the movable portion 201 has extension portions 201b and 201c extending in the direction of the first axis AX1. Accordingly, as in the case of the mobile device 100, it is possible to suppress changes in the scanning angle and the scanning center of the reflecting section 202 due to the influence of gravity. In the movable device 200, modifications similar to those in FIGS. 5 to 9 may be applied.

FIG. 12 is a plan view (viewed from the reflective surface side) of an optical deflector that is a movable device according to Modification 1 of the second embodiment. A movable device 200A shown in FIG. 12 has a cantilever structure in which a movable portion having a reflecting surface is rotated to deflect light incident on the reflecting surface in one axial direction (around a first axis AX1 parallel to the X axis). is an optical deflector.

Unlike the movable device 200, the movable device 200A has a cantilever structure, and therefore, like the drive portions 203c and 203d, the drive portions are provided only on one side of the first axis AX1.

In the movable device 200A, similarly to the movable device 200, the bending vibration of the beam portion 215 is converted into rotational vibration (torsional vibration) by the torsion beams 220a and 220b, thereby moving the movable portion 201 including the reflecting portion 202 along the first axis. It can rotate around AX1.

Even in the case of a cantilever structure like the movable device 200A, the movable portion 201 has extension portions 201b and 201c that extend in the direction of the first axis AX1, so that the influence of gravity is reduced as in the case of the movable device 200. It is possible to suppress the change in the scanning angle of the reflecting section 202 and the change in the scanning center due to the . In the movable device 200A, modifications similar to those shown in FIGS. 5 to 9 may be applied.

<Third embodiment>
The third embodiment shows an example of a biaxial optical deflector using the movable device according to the first and second embodiments. In this embodiment, optical scanning around the first axis AX1 is defined as sub-scanning, and optical scanning around the second axis AX2 is defined as main scanning.

FIG. 13 is a plan view (viewed from the reflecting surface side) of an optical deflector that is a movable device according to the third embodiment.

Referring to FIG. 13, the movable device 100D is an optical deflector with a double-end support structure. The movable device 100D has a structure that enables the movable portion 201 including the reflecting portion 202 and the movable portion 101 to rotate around a first axis AX1 parallel to the X axis. In addition, the movable device 100D has a structure that allows the movable portion 201 including the reflecting portion 202 to rotate around the second axis AX2 parallel to the Y-axis. That is, the movable device 100D rotates the movable portion 201 including the reflecting portion 202 in two axial directions (around the first axis AX1 and the second axis AX2), thereby scanning incident light in two axial directions. Deflectable.

The movable device 100D has an opening inside the central portion 101a of the movable device 100, and the movable portion 201 and the like are arranged in the opening. That is, a structure corresponding to the inner side of the support portion 204 of the movable device 200 is arranged in the opening. The movable portion 201 is supported by the central portion 101a so as to be rotatable about a second axis AX2 perpendicular to the first axis AX1. In addition, unlike the movable device 200, the movable part 201 of the movable device 100D does not have an extending portion. In the movable device 100D, both the longitudinal direction of the beam portion 115 and the longitudinal directions of the torsion beams 220a and 220b face the Y direction (the direction of the second axis AX2).

In movable device 100D, the structural portion corresponding to movable device 100 contributes to rotation in the sub-scanning direction, and the structural portion corresponding to movable device 200 contributes to rotation in the main scanning direction (fast axis). That is, the drive units 103a and 103b swing the movable unit 101 including the movable unit 201 around the first axis AX1. Further, the driving portions 203a and 203b swing the movable portion 201 around a second axis AX2 orthogonal to the first axis AX1.

Thus, in the movable device 100D, the movable portion 101 has extension portions 101b and 101c extending in the direction of the first axis AX1. As a result, as in the case of the mobile device 100, it is possible to suppress changes in the scanning angle and scanning center of the reflecting section 202 due to the influence of gravity with respect to the rotation in the direction of the first axis AX1. In the movable device 100D, modifications similar to those shown in FIGS. 5 to 9 may be applied.

FIG. 14 is a plan view (viewed from the reflective surface side) of an optical deflector that is a movable device according to Modification 1 of the third embodiment. A movable device 100E shown in FIG. 14 is different from the movable device 100D (see FIG. 13) in that the movable portion 201 has extending portions 201b and 201c extending in the direction in which the second axis AX2 extends.

Like the movable device 100E, the movable part 101 may have extensions 101b and 101c, and the movable part 201 may have extensions 201b and 201c. As a result, as in the case of the mobile device 100D, it is possible to suppress changes in the scanning angle and scanning center of the reflecting section 202 due to the influence of gravity with respect to the rotation in the direction of the first axis AX1. Furthermore, regarding the rotation in the direction of the second axis AX2, it is possible to suppress the change in the scanning angle and the change in the scanning center of the reflection section 202 due to the influence of gravity.

The movable devices according to the first to third embodiments and modifications described above can be used for optical scanning systems, image projection devices, optical writing devices, and object recognition devices.

[Optical scanning system]
First, with reference to FIGS. 15 to 18, an optical scanning system equipped with any one of the movable devices according to the first to third embodiments and modifications will be described in detail.

FIG. 15 shows a schematic diagram of an example of an optical scanning system.

As shown in FIG. 15, the optical scanning system 10 is a system that optically scans a surface 15 to be scanned by deflecting light emitted from a light source device 12 by a reflecting surface 14 of a movable device 13 under the control of a driving device 11 . be. The movable device 13 is any one of the movable devices according to the first to third embodiments and modifications.

The optical scanning system 10 includes a drive device 11 , a light source device 12 and a movable device 13 having a reflective surface 14 . Optical scanning system 10 is a representative example of a deflection device according to the present invention.

The driving device 11 is an electronic circuit unit including, for example, a CPU (Central Processing Unit) and an FPGA (Field-Programmable Gate Array). The movable device 13 is, for example, a MEMS (Micro Electromechanical Systems) device having a reflecting surface 14 and capable of moving the reflecting surface 14 . The light source device 12 is, for example, a laser device that emits laser light. Note that the scanned surface 15 is, for example, a screen.

The driving device 11 generates control commands for the light source device 12 and the movable device 13 based on the acquired optical scanning information, and outputs drive signals to the light source device 12 and the movable device 13 based on the control commands.

The light source device 12 irradiates the light source based on the input drive signal. The movable device 13 moves the reflecting surface 14 in at least one or two axial directions based on the input drive signal.

As a result, the driving device 11 reciprocates the reflecting surface 14 of the movable device 13 in a predetermined range in two axial directions by control based on image information, which is an example of optical scanning information, for example. The irradiation light from the light source device 12 is deflected and optically scanned. As a result, the driving device 11 can project any image onto the scanned surface 15 .

Details of the control by the driving device 11 will be described later.

Next, an example hardware configuration of the optical scanning system 10 will be described with reference to FIG.

FIG. 16 is a hardware configuration diagram of an example of the optical scanning system 10. As shown in FIG.

As shown in FIG. 16, the optical scanning system 10 includes a driving device 11, a light source device 12 and a movable device 13, which are electrically connected to each other.

[Driving device]
The driving device 11 includes a CPU 20 , a RAM 21 (Random Access Memory), a ROM 22 (Read Only Memory), an FPGA 23 , an external I/F 24 , a light source device driver 25 and an optical deflector driver 26 .

The CPU 20 is an arithmetic device that reads programs or data from a storage device such as a ROM 22 onto a RAM 21 and executes processing to achieve overall control and functions of the drive device 11 . The RAM 21 is a volatile storage device that temporarily holds programs or data.

The ROM 22 is a non-volatile storage device capable of retaining programs or data even when power is turned off, and stores processing programs or data executed by the CPU 20 to control each function of the optical scanning system 10 . there is

The FPGA 23 is a circuit that outputs control signals suitable for the light source device driver 25 and the optical deflector driver 26 according to the processing of the CPU 20 .

The external I/F 24 is an interface with, for example, an external device or network. External devices include, for example, host devices such as PCs (Personal Computers), and storage devices such as USB memories, SD cards, CDs, DVDs, HDDs, or SDs. The network is, for example, a CAN (Controller Area Network) of an automobile, a LAN (Local Area Network), or the Internet. The external I/F 24 may be configured to enable connection or communication with an external device, and the external I/F 24 may be prepared for each external device.

The light source device driver 25 is an electric circuit that outputs a drive signal such as a drive voltage to the light source device 12 according to the input control signal.

The optical deflector driver 26 is an electric circuit that outputs a driving signal such as a driving voltage to the movable device 13 according to the input control signal.

In the drive device 11 , the CPU 20 acquires optical scanning information from an external device, network, or the like via the external I/F 24 . The driving device 11 may be configured so that the CPU 20 can acquire the optical scanning information, and may be configured to store the optical scanning information in the ROM 22 or the FPGA 23 in the driving device 11 . Further, the driving device 11 may be configured such that a storage device such as an SSD is newly provided inside and optical scanning information is stored in the storage device.

Here, the optical scanning information is information indicating how to optically scan the surface 15 to be scanned. For example, when an image is displayed by optical scanning, the optical scanning information is image data. Further, for example, when optical writing is performed by optical scanning, the optical scanning information is writing data indicating the writing order or writing location. In addition, for example, when object recognition is performed by optical scanning, the optical scanning information is irradiation data indicating the timing and irradiation range of irradiation with light for object recognition.

The driving device 11 can implement the functional configuration described below by means of commands from the CPU 20 and the hardware configuration shown in FIG.

[Functional Configuration of Driving Device]
Next, with reference to FIG. 17, the functional configuration of the driving device 11 of the optical scanning system 10 will be described. FIG. 17 is a functional block diagram of an example of a driving device for an optical scanning system.

As shown in FIG. 17, the drive device 11 has a control section 30 and a drive signal output section 31 as functions.

The control unit 30 is implemented by, for example, the CPU 20 and the FPGA 23 , acquires optical scanning information from an external device, converts the optical scanning information into control signals, and outputs the control signals to the drive signal output unit 31 . For example, the control unit 30 is a control means, acquires image data as optical scanning information from an external device or the like, generates a control signal from the image data through predetermined processing, and outputs the control signal to the drive signal output unit 31 .

The drive signal output unit 31 is an application means, is realized by the light source device driver 25, the optical deflector driver 26, etc., and outputs a drive signal to the light source device 12 or the movable device 13 based on the input control signal. The drive signal output section 31 (applying means) may be provided, for example, for each target to which the drive signal is output.

The drive signal is a signal for controlling driving of the light source device 12 or the movable device 13 . For example, in the light source device 12, the drive signal is a drive voltage for controlling the irradiation timing and irradiation intensity of the light source. Further, for example, in the movable device 13 , the drive signal is a drive voltage that controls the timing and movable range of moving the reflecting surface 14 of the movable device 13 . The driving device may acquire the irradiation timing and the light receiving timing of the light source from an external device such as the light source device 12 or the light receiving device, and synchronize them with the driving of the movable device 13 .

[Optical scanning process]
Next, with reference to FIG. 18, the process of optically scanning the surface 15 to be scanned by the optical scanning system 10 will be described. FIG. 18 is a flowchart of an example of processing related to the optical scanning system.

In step S11, the control unit 30 acquires optical scanning information from an external device or the like.

In step S<b>12 , the control section 30 generates a control signal from the acquired optical scanning information and outputs the control signal to the drive signal output section 31 .

In step S13, the drive signal output unit 31 outputs drive signals to the light source device 12 and the movable device 13 based on the input control signal.

In step S14, the light source device 12 performs light irradiation based on the input drive signal. Also, the movable device 13 moves the reflecting surface 14 based on the input drive signal. By driving the light source device 12 and the movable device 13, the light incident on the reflecting surface 14 is deflected in an arbitrary direction and optically scanned.

In the optical scanning system 10, one drive device 11 controls the light source device 12 and the movable device 13. However, a drive device for controlling the light source device 12 and a drive device for controlling the movable device 13 are provided separately. good too.

Further, in the optical scanning system 10 , one drive device 11 is provided with the function of the control section 30 and the function of the drive signal output section 31 . However, these functions may exist separately. For example, a drive signal output device having a drive signal output section 31 may be provided separately from the drive device 11 having the control section 30 . In the optical scanning system 10, the movable device 13 having the reflecting surface 14 and the driving device 11 may constitute an optical deflection system that deflects the light.

By using any one of the movable devices according to the first to third embodiments and modifications in the optical scanning system, changes in the scanning angle of the movable device and changes in the scanning center due to the influence of gravity are suppressed, resulting in high accuracy. can be optically scanned.

[Image projection device]
Next, with reference to FIGS. 19 and 20, an image projection device to which the movable device 13 is applied will be described in detail.

FIG. 19 is a schematic diagram of an embodiment of an automobile 400 equipped with a head-up display device 500, which is an example of an image projection device. Also, FIG. 20 is a schematic diagram of an example of the head-up display device 500 .

An image projection device is a device that projects an image by optical scanning, such as a head-up display device.

As shown in FIG. 19, the head-up display device 500 is installed near the windshield (windshield 401 etc.) of the automobile 400, for example. The projection light L emitted from the head-up display device 500 is reflected by the windshield 401 and travels toward the observer (driver 402) who is the user.

Accordingly, the driver 402 can visually recognize the image or the like projected by the head-up display device 500 as a virtual image. A combiner may be installed on the inner wall surface of the windshield so that the user can visually recognize the virtual image by projected light reflected by the combiner.

As shown in FIG. 20, the head-up display device 500 emits laser light from red, green, and blue laser light sources 501R, 501G, and 501B. The emitted laser light enters an incident optical system including collimator lenses 502, 503, and 504 provided for each laser light source, two dichroic mirrors 505 and 506, and a light amount adjuster 507. FIG. Then, the laser light that has passed through the incident optical system is deflected by the movable device 13 having the reflecting surface 14 .

The deflected laser light passes through a projection optical system including a free-form surface mirror 509, an intermediate screen 510, and a projection mirror 511, and is projected onto a screen.

In the head-up display device 500, the laser light sources 501R, 501G and 501B, the collimating lenses 502, 503 and 504, and the dichroic mirrors 505 and 506 are unitized as a light source unit 530 with an optical housing.

The head-up display device 500 projects the intermediate image displayed on the intermediate screen 510 onto the windshield 401 of the automobile 400 so that the driver 402 can visually recognize the intermediate image as a virtual image.

The respective color laser beams emitted from the laser light sources 501R, 501G, and 501B are collimated by collimating lenses 502, 503, and 504, respectively, and combined by two dichroic mirrors 505 and 506, respectively. The combined laser light is two-dimensionally scanned by the movable device 13 having the reflecting surface 14 after the light amount is adjusted by the light amount adjusting unit 507 . The projection light L that has been two-dimensionally scanned by the movable device 13 is reflected by the free-form surface mirror 509 and corrected for distortion, and then converged on the intermediate screen 510 to display an intermediate image. The intermediate screen 510 is, for example, a microlens array in which microlenses are two-dimensionally arranged, and magnifies the projection light L incident on the intermediate screen 510 in units of microlenses.

The movable device 13 reciprocates the reflecting surface 14 in two axial directions, and two-dimensionally scans the projection light L incident on the reflecting surface 14 . The reflecting surface 14 of the movable device 13 is controlled in synchronization with the light emission timings of the laser light sources 501R, 501G, and 501B.

The head-up display device 500 has been described above as an example of an image projection device. Any device other than a head-up display device may be used.

The image projection device can equally be applied to a projector that is placed on, for example, a desk and projects an image onto a display screen. In addition, the image projection device is mounted on a mounting member worn on the head of the observer, etc., and projects on a reflection-transmitting screen of the mounting member, or a head-mounted display device that projects an image using the eyeball as a screen. can be applied as well.

In addition, the image projection device can be applied not only to a vehicle or a mounting member, but also to a mobile object such as an aircraft, a ship, and a mobile robot, or a work robot that operates a driven object such as a manipulator without moving from its place. may be mounted on a non-moving object.

By using any one of the movable devices according to the first to third embodiments and modifications in the image projection device, changes in the scanning angle and scanning center of the movable device due to the influence of gravity are suppressed, resulting in high accuracy. image projection becomes possible.

[Optical writing device]
Next, an optical writing device to which the movable device 13 is applied will be described in detail with reference to FIGS. 21 and 22. FIG.

FIG. 21 shows an example of an image forming apparatus in which the optical writing device 600 is incorporated. Also, FIG. 22 is a schematic diagram of an example of an optical writing device.

As shown in FIG. 21, the optical writing device 600 is used as a constituent member of an image forming apparatus typified by a laser printer 650 having a printer function using laser light. In the image forming apparatus, the optical writing device 600 performs optical writing on the photosensitive drum by optically scanning the photosensitive drum, which is the surface to be scanned 15, with one or a plurality of laser beams.

As shown in FIG. 22, in an optical writing device 600, a laser beam from a light source device 12 such as a laser element passes through an imaging optical system 601 such as a collimating lens, and then passes through a movable device 13 having a reflecting surface 14. Axially or biaxially deflected.

Then, the laser beam deflected by the movable device 13 passes through the scanning optical system 602 including the first lens 602a, the second lens 602b, and the reflecting mirror portion 602c, and passes through the surface to be scanned 15 (for example, a photosensitive drum or a photosensitive drum). paper) to perform optical writing. The scanning optical system 602 forms a spot-like light beam on the surface 15 to be scanned.

Also, the movable device 13 having the light source device 12 and the reflecting surface 14 is driven based on the control of the driving device 11 .

Thus, the optical writing device 600 can be used as a component of an image forming apparatus having a printer function using laser light.

In addition, the optical writing device 600 can perform optical scanning not only in one axial direction but also in two axial directions by using different scanning optical systems. The optical writing device 600 can be used, for example, as a component of an image forming apparatus such as a laser label device that deflects a laser beam onto a thermal medium, optically scans it in two axial directions, and heats the thermal medium to print. can be done.

The movable device 13 having the reflecting surface 14 applied to the optical writing device consumes less power for driving than a rotating polygonal mirror using a polygon mirror or the like, so it contributes to power saving of the optical writing device. Advantageous.

In addition, since wind noise when the movable device 13 vibrates is smaller than that of the rotating polygon mirror, it is advantageous for improving the quietness of the optical writing device. The optical writing device requires an overwhelmingly smaller installation space than the rotary polygon mirror, and the amount of heat generated by the movable device 13 is also very small. be.

By using any of the movable devices according to the first to third embodiments and modifications as an optical writing device, changes in the scanning angle of the movable device and changes in the scanning center due to the influence of gravity are suppressed. Accurate optical writing becomes possible.

[Object recognition device]
Next, an object recognition device to which the movable device 13 is applied will be described in detail with reference to FIGS. 23 and 24. FIG.

FIG. 23 is a schematic diagram of an automobile equipped with a laser radar device, which is an example of an object recognition device. Also, FIG. 24 is a schematic diagram of an example of a laser radar device.

An object recognition device is a device that recognizes an object in a target direction, such as a laser radar device.

As shown in FIG. 23, a laser radar device 700 is mounted on, for example, an automobile 701, optically scans a target direction, and receives reflected light from a target object 702 existing in the target direction. 702 is recognized.

As shown in FIG. 24, the laser light emitted from the light source device 12 passes through an incident optical system including a collimating lens 703, which is an optical system that converts diverging light into substantially parallel light, and a plane mirror 704, and passes through the reflecting surface 14. is scanned in one or two axial directions by a movable device 13 having a

The laser beams scanned in the biaxial directions are irradiated onto an object 702 in front of the device through a projection lens 705 or the like, which is a projection optical system. The driving of the light source device 12 and the movable device 13 is controlled by the driving device 11 . Reflected light reflected by the target object 702 is photodetected by a photodetector 709 .

That is, the light reflected by the target object 702 is received by the imaging device 707 via the condenser lens 706 and the like, which is a light receiving optical system, and the imaging device 707 outputs a detection signal to the signal processing circuit 708 . The signal processing circuit 708 performs predetermined processing such as binarization or noise processing on the input detection signal, and outputs the result to the distance measurement circuit 710 .

The distance measuring circuit 710 detects the target by the time difference between the timing at which the light source device 12 emits the laser beam and the timing at which the photodetector 709 receives the laser beam, or the phase difference for each pixel of the image sensor 707 that receives the laser beam. The presence or absence of the object 702 is recognized. The distance measurement circuit 710 also calculates distance information to the target object 702 .

Since the movable device 13 having the reflecting surface 14 is less likely to be damaged than a polygonal mirror and is small, it is possible to provide a compact radar device with high durability.

Such a laser radar device is mounted on a moving body such as a vehicle, an aircraft, a ship, and a mobile robot, or a non-moving body such as a working robot that operates a driven object such as a manipulator without moving from the spot. can. Then, the laser radar device can recognize the presence or absence of an obstacle or the distance to the obstacle by optically scanning a predetermined range.

Although the laser radar device 700 has been described above as an example of the object recognition device, the object recognition device is not limited to the laser radar device. The object recognition device performs optical scanning by controlling the movable device 13 having the reflecting surface 14 with the driving device 11, and recognizes the target object 702 by receiving the reflected light with the photodetector. , other than the laser radar device.

The object recognition device can be applied to biometric authentication, for example, in which object information such as shape is calculated from distance information obtained by optically scanning a hand or face, and the object is recognized by referring to the recording. can. In addition, the object recognition device calculates and recognizes object information such as shape from the security sensor that recognizes an intruding object by optically scanning the target range, and the distance information obtained by the optical scanning, and outputs it as three-dimensional data 3 The same can be applied to components of dimensional scanners and the like.

By using any one of the movable devices according to the first to third embodiments and modifications as an object recognition device, changes in the scanning angle and scanning center of the movable device due to the influence of gravity are suppressed, resulting in high accuracy. object recognition becomes possible.

[Packaging]
Next, with reference to FIG. 25, packaging of the movable device 13, which is an optical deflector, will be described.

FIG. 25 is a schematic diagram of an example of a packaged optical deflector.

As shown in FIG. 25 , the movable device 13 is attached to an attachment member 802 arranged on the bottom surface of a concave package member 801 . The package member 801 is provided with a transparent member 803 that covers the area where the movable device 13 is arranged. The movable device 13 is packaged by sealing with the package member 801 and the transparent member 803 .

Furthermore, the inside of the package is sealed with an inert gas such as nitrogen. As a result, deterioration due to oxidation of the movable device 13 is suppressed, and durability against environmental changes such as temperature is improved.

Although the preferred embodiments and the like have been described in detail above, the present invention is not limited to the above-described embodiments and the like, and various modifications and substitutions can be made to the above-described embodiments and the like without departing from the scope of the claims. can be added.

For example, in each of the above-described embodiments, an example of using a piezoelectric driving method using a piezoelectric element as a driving means for swinging the movable portion was shown, but the present invention is not limited to this, and driving is performed using, for example, electrostatic force. An electrostatic drive system or an electromagnetic drive system using electromagnetic force may be used. In addition, in the third embodiment, the driving means for swinging the movable portion in the main scanning direction and the driving means for swinging the movable portion in the sub-scanning direction both employ the same driving method, but they are different from each other. You may employ a drive system.

In each of the above embodiments, the movable portion has a reflecting portion, but instead of the reflecting portion, the movable portion includes a diffraction grating, a photodiode, a heater (for example, a heater using SiN), a light source (for example, a plane light-emitting type laser) or the like.

10 optical scanning system 12 light source device 13 movable device 14 reflective surface 15 surface to be scanned 20 CPU
21 RAM
22 ROMs
23 FPGAs
24 External I/F
25 light source device driver 26 optical deflector driver 30 control section 31 drive signal output section 100, 100A, 100B, 100C, 100D, 100E, 200, 200A movable device 101, 201 movable section 101a, 201a central section 101b, 101c, 201b, 201c extensions 101d, 101e, 101f, 101g projections 102, 202 reflections 102a, 202a reflection surfaces 103a, 103b, 203a, 203b, 203c, 203d driving parts 104a, 104b, 204 support 108 projections 115, 215 beams Part 116 Connection parts 117a, 117b Movable part connection parts 118a, 118b Support part connection parts 119a, 119b Drive element group 131 Silicon support layer 132 Silicon oxide layer 133 Silicon active layer 135 Lower electrode 136 Piezoelectric part 137 Upper electrodes 219a, 219b Drive element 220a, 220b Torsion beam 400 Automobile 401 Windshield 402 Driver 500 Head-up display device 501R, 501G, 501B Laser light source 502, 503, 504 Collimating lens 505, 506 Dichroic mirror 507 Light amount adjusting unit 509 Free curved surface mirror 510 Intermediate screen 511 Projection Mirror 530 Light source unit 600 Optical writing device 601 Imaging optical system 602 Scanning optical system 602a First lens 602b Second lens 602c Reflecting mirror section 650 Laser printer 700 Laser radar device 701 Automobile 702 Target object 703 Collimating lens 704 Plane mirror 705 Projection lens 706 Condensing lens 707 Imaging element 708 Signal processing circuit 709 Photodetector 710 Distance measuring circuit 801 Package member 802 Mounting member 803 Transmission member

JP 2020-003531 A

Claims (17)

a movable part rotatable about a predetermined axis;
a drive unit having one end connected to the movable unit and rotating the movable unit;
A movable device, wherein the movable portion has an extending portion extending in a direction in which the predetermined axis extends. 2. The movable device according to claim 1, wherein the extending portion has a longitudinal direction parallel to the predetermined axis. The movable device according to claim 1 or 2, wherein the extending portion has a protrusion that protrudes on one side in the thickness direction. The movable part according to any one of claims 1 to 3, wherein the movable part has a projecting part projecting in a direction opposite to the driving part at a longitudinal end of the extending part in a plan view. Device. The movable device according to any one of claims 1 to 4, wherein the movable portion has a protruding portion that protrudes toward the driving portion from a longitudinal end portion of the extending portion in plan view. The movable device according to any one of claims 1 to 5, wherein the drive section has a meander structure in which a plurality of beam sections are connected by a connection section. 6. The movable device according to any one of claims 1 to 5, comprising a pair of torsion beams having one end connected to both sides of the movable portion and the other end connected to the drive portion. The movable device according to any one of claims 1 to 7, wherein the movable portion has a symmetrical planar shape and mass with respect to the predetermined axis. The movable part has a central part arranged to straddle the predetermined axis,
The extending portion includes a first extending portion extending in a direction in which the predetermined axis extends from both sides of one end portion of the central portion in a direction orthogonal to the predetermined axis, and a first extending portion extending in the direction in which the predetermined axis extends from the central portion. The movable device according to any one of claims 1 to 8, further comprising: a second extending portion extending in a direction in which the predetermined axis extends from both sides of the other end portion in a direction perpendicular to the direction of the movable device. The movable device according to claim 9, wherein one surface of said central portion is provided with a reflecting portion. The movable device according to claim 10, wherein the reflecting portion is provided on the entire surface of each one of the central portion, the first extending portion, and the second extending portion. The central portion has an opening,
A second movable part is arranged inside the opening,
The movable device according to any one of claims 9 to 11, wherein said second movable portion is supported by said central portion so as to be rotatable about another axis orthogonal to said predetermined axis. 13. The movable device according to claim 12, wherein said second movable portion has an extending portion extending in a direction in which said other axis extends. A mobile device according to any one of claims 1 to 13;
a light source;
A deflection device with a An object recognition device comprising the movable device according to any one of claims 1 to 13. An image projection device comprising a movable device according to any one of claims 1 to 13. A moving object comprising at least one of the object recognition device according to claim 15 and the image projection device according to claim 16.

Images