JP2019015934A - Driving device - Google Patents

Abstract

To perform widening of a rotational angle or adjustment of a resonance frequency, by syntheses of resonances of a driven part and resonances of deforming vibrations in the shape of standing waves.SOLUTION: The present driving device makes: a base part and a torsion bar perform deforming vibrations in the shape of standing waves, with vibrations generated by periodically applying vibrations to a drive source part arranged in the base part; and a mirror (driven part) supported by the base part rotate resonantly at a frequency of the standing-wave-shaped deforming vibrations that is different from a resonance frequency of a mirror part (and determined by a support part).SELECTED DRAWING: Figure 1

Description

  The present invention relates to a technical field of a driving device such as a MEMS mirror driving device that rotates a driven object such as a mirror.

  The mirror driving device is used in various technical fields such as a scanner, a barcode reader, a printing device, a laser radar, a display, a retinal scanning display, precision measurement, precision processing, and information recording / reproduction. There are MEMS devices manufactured by semiconductor process technology and apparatuses using inexpensive processing methods such as metal etching, precision metal punching, laser cutting, etc., without using semiconductor technology fine fine processing technology. A scanning field that scans light on a predetermined screen area and receives reflected light to read image information, or a display that displays an image by scanning light incident from a light source on a predetermined screen area In the field, a micro-structured mirror driving device (MEMS mirror driving device) has attracted attention.

As the mirror driving device, the following driving device shown in Patent Document 1 is known.
The drive device connects the base part, a rotatable driven part (mirror), the base part and the driven part, and rotates the driven part about an axis along one direction as a central axis. The driven portion and the driven portion so that the driven portion rotates at a resonance frequency determined by the driven portion and the elastic portion while resonating around an axis along the one direction as a central axis. And an application unit that applies micro vibrations for rotating the unit to the base unit.

Patent No. 5624213 Patent Gazette Patent No. 6014234 Patent Gazette Patent No. 4958195 Patent Gazette

  In the mirror driving device having such a configuration, a driving force is not directly applied to the driven portion (mirror), and an excitation force having a resonance frequency determined by the driven portion (mirror) and the elastic portion is applied to the base portion. In this example, vibration is propagated from the base portion to the driven portion, and the driven portion is resonantly driven at the resonance frequency. However, in such a conventional drive device, there is a problem that the use efficiency of the excitation force is not sufficient, a necessary mirror rotation angle cannot be obtained, power consumption is large, or the device is enlarged. There is also a problem that the resonance frequency of the mirror cannot be increased.

In such a conventional mirror driving apparatus, there are problems of enlargement of the mirror rotation angle, low power consumption, miniaturization of the apparatus, and a high resonance frequency of the mirror to achieve high definition.

  In view of the above problems, a drive device according to the present invention connects a first base portion, a second base portion supported by the first base portion, the first base portion and the second base portion, and A first elastic portion having elasticity that rotates the second base portion about an axis along another direction as a rotation axis, a rotatable driven portion, and the second base portion and the driven portion are connected to each other. And a second elastic part having elasticity that rotates the driven part about an axis along one direction different from the other direction and an application for applying a driving force to the second base part. The drive force application unit includes the first elastic part a, the second base part (including the second elastic part and the driven part), and the first elastic part b along the other direction. Apply a periodic excitation force so that the deformation vibration is in a standing wave shape and the deformation vibration becomes resonance, Due to the ordinary wave-like deformation vibration, the driven part resonates and rotates with the axis along the one direction as a central axis, and the resonance wave-like deformation vibration causes the resonance frequency of the driven part to transition, The resonance frequency of the driven part is different from the resonance frequency determined by the driven part and the second elastic part.

  In the present invention, since the frequency transition effect and the resonance synthesis effect due to the stationary wave-like deformation vibration of the second base portion and the first elastic portion are appropriately used, a larger rotation angle can be obtained, higher efficiency, lower A power consumption drive device can be provided. Further, there is an advantage that the resonance frequency of the driven part (mirror) can be increased and the definition can be increased.

  Such an operation and gain of the present invention will be clarified from the embodiments described below.

It is a top view which shows notionally the structure of the MEMS mirror drive device based on 1st Example. It is a side view which shows notionally the mode of operation by the MEMS mirror drive device concerning the 1st example. It is a side view which shows notionally the mode of operation by the MEMS mirror drive device concerning the 1st example. It is a side view which shows notionally the mode of operation by the MEMS mirror drive device concerning the 1st example. It is a top view which shows notionally the structure of the MEMS mirror drive device based on 2nd Example. It is a side view which shows notionally the aspect of the operation | movement by the MEMS mirror drive device which concerns on 2nd Example. It is a side view which shows notionally the aspect of the operation | movement by the MEMS mirror drive device which concerns on 2nd Example. It is a side view which shows notionally the aspect of the operation | movement by the MEMS mirror drive device which concerns on 2nd Example. It is a top view which shows notionally the structure of the MEMS mirror drive device which concerns on 3rd Example. It is a top view which shows notionally the structure of the MEMS mirror drive device which concerns on 4th Example. It is a side view which shows notionally the aspect of the operation | movement by the MEMS mirror drive device which concerns on 4th Example. It is a top view which shows notionally the structure of the MEMS mirror drive device which concerns on 5th Example. It is a side view which shows notionally the aspect of the operation | movement by the MEMS mirror drive device which concerns on 5th Example.

Hereinafter, embodiments according to the drive device will be described in order.
The driving apparatus of the present embodiment connects the first base portion, the second base portion supported by the first base portion, the first base portion and the second base portion, and the second base portion. Connecting the first elastic part having elasticity such that the axis along the other direction as a rotation axis, a rotatable driven part, the second base part and the driven part and connecting the driven part A second elastic part having elasticity so as to rotate the drive part about an axis along one direction different from the other direction as a rotation axis; a coil part disposed on the second base part; and the coil A magnetic field applying part that applies a magnetic field to the part, and the coil part includes the first elastic part a and the second base part (including the second elastic part and the driven part) along the other direction. And the first elastic portion b deforms and vibrates in a standing wave shape, and the deformed vibration becomes resonance. A periodic excitation force is applied to the driven portion, and the driven part resonates and rotates about the axis along the one direction as a central axis due to the stationary wave-like deformation vibration. The resonance frequency of the driving unit is changed, and the resonance frequency of the driven unit is different from the resonance frequency determined by the driven unit and the second elastic unit.

  According to the drive device of the present embodiment, the first base portion serving as the foundation and the second base portion supported by the first base portion are connected by the first elastic portion having elasticity. Furthermore, the second base portion and a driven portion (for example, a mirror described later) rotatably supported are connected by a second elastic portion having elasticity. The second base portion is based on the torsional elasticity of the first elastic portion (for example, the elasticity that the second base portion can be rotated about an axis along another direction (for example, an X-axis direction described later) as a rotation axis). Rotate the axis along the other direction as the axis of rotation. Therefore, the driven part connected to the second base part via the second elastic part also has an axis along the other direction as a rotation axis (the second base part and the driven part are integrated). Rotate.

In addition, the driven portion is torsionally elastic of the second elastic portion (for example, elasticity that the driven portion can be rotated about an axis along one direction (Y-axis direction described later) as a rotation axis). , And an axis along one direction different from the other direction (preferably orthogonal) is rotated as a rotation axis. In other words, the driving device of the present embodiment has a single-axis drive of the driven part with the axis along one direction as the rotation axis, and both the axis along one direction and the axis along the other direction. The driven part can be driven in two axes with the rotation axis as the rotation axis.
However, the drive apparatus of this embodiment may perform multi-axis drive (for example, 3-axis drive, 4-axis drive,...) Of the driven part.

  In the aspect of the driving device in which the rigidity of a part of the second base part is higher than the rigidity of the other part of the second base part, the rigidity of the side along the direction of the Y axis is set to the direction of the X axis. It is preferable to make it higher than the rigidity of the side along. However, the high bending rigidity mentioned here indicates that the natural frequency (resonance frequency) in the natural vibration mode is high.

  In the drive device according to the present embodiment, the driven part is rotated by the force caused by the current flowing in the coil part. In other words, the driving force for rotating the driven part is an electromagnetic force resulting from the electromagnetic interaction between the coil part and the magnetic field applying part.

  More specifically, the coil part is supplied with a control current for rotating the driven part about an axis along one direction as a rotation axis. For example, the control current is preferably an alternating current having the same frequency as the frequency at which the driven part rotates with an axis along one direction as a rotation axis. That is, the control current is preferably an alternating current having the same frequency as that of a stationary wave-like deformation vibration described later including the driven portion, the second elastic portion, the first elastic portion, and the second base portion. On the other hand, a magnetic field is applied to the coil unit from the magnetic field applying unit. For this reason, a Lorentz force is generated in the coil portion due to electromagnetic interaction between the control current supplied to the coil portion and the magnetic field applied by the magnetic field applying portion.

  This Lorentz force generates vibration in the coil portion. This vibration generates a standing wave-like deformation vibration. In other words, the electromagnetic force generated by the coil portion generates deformation waves having a standing wave shape with the second base portion and the first elastic portion. This standing wave-like deformation vibration causes the driven part to resonate and rotate.

  The standing wave deformation vibration (standing wave deformation vibration with the second base portion and the first elastic portion) will be described. In the driving device of the present embodiment, due to the periodic electromagnetic excitation force generated by the coil portion, the spring elasticity and mass of each portion (including the first elastic portion and the second base portion (including the driven portion and the second elastic portion)). Standing wave-like resonance occurs. In this resonance, the first elastic part a, the second base part (including the driven part and the second elastic part), and the first elastic part b are connected along the other direction, like the double mode of the string. Shows deformed appearance.

  At this time, a belly and a node appear along the other direction in the standing wave-like deformation vibration. That is, a belly appears at the connection portion between the first elastic part a and the second base part, a node (two) and a belly appear at the second base part (including the driven part and the second elastic part), and the first Resonance having a mode in which an antinode appears in a connection portion between the first elastic portion b and the second base portion. Deformation vibration in which the second base portion and the first elastic portion (including the driven portion and the second elastic portion) are coupled (hereinafter referred to as standing wave-shaped deformation vibration with the second base portion and the first elastic portion). ) Shows a so-called standing wave-like deformation state, and the positions of the antinodes and nodes are substantially fixed.

  In the driving apparatus of the present embodiment, the rotational resonance of the driven part and the stationary wave-like deformation vibration (coupled vibration) of the second base part and the first elastic part are generated at the same frequency. Strictly speaking, the resonance frequency of the driven part is changed by a standing wave-like deformation vibration of the second base part and the first elastic part. Therefore, the resonance frequency of the driven part at this time is different from the resonance frequency determined by the driven part and the second elastic part.

  In addition, since the resonance frequency of the driven part is changed by the standing wave-like deformation vibration of the second base part and the first elastic part, the resonance frequency of the driven part is typically the driven part. The resonance frequency is higher than the resonance frequency determined by the portion and the second elastic portion.

In addition, the transition of resonance, that is, the synthesis of resonance is accurately performed, that is, the rotational resonance of the driven part and the steady wave resonance of the second base part and the first elastic part are accurately performed. Therefore, the driven member rotates at a larger rotation angle, and a driving device with higher efficiency and lower power consumption can be provided. Therefore, according to the drive device of this embodiment, when vibration is performed using the same electric power, resonance of the driven part due to stationary wave-like deformation vibration between the second base part and the first elastic part. The amount of rotation of the driven part can be increased compared to the case where frequency transition is not performed. That is, the rotational amplitude of the driven part per unit power can be increased.

  Further, the position of the vibration node (driven part side) on the second base part in the standing wave-like deformation vibration of the second base part and the first elastic part corresponds to the rotation axis of the driven part, In other words, it is preferable to match the position of the rotation axis of the second elastic portion. In this way, unnecessary vibration (translation) of the driven part is suppressed, and the driven part can be efficiently rotated. However, the agreement here does not have to be an exact agreement, and the position of the node may be adjusted as appropriate in consideration of the balance with other design conditions.

  In order to realize the above-described standing-wave deformation vibration, the rigidity, mass, length, and width of the first elastic part a, the second base part (including the second elastic part and the driven part), and the first elastic part b Etc. are adjusted. Specifically, it is preferable to adjust the length, width, shape, cross-sectional shape, rigidity, shape of the second base portion, mass, rigidity, shape of the coil portion, and the like of the first elastic portion. By adjusting these, the positions of the nodes and antinodes become appropriate, the transition of the resonance frequency of the driven part is performed, the above-mentioned stationary wave-like deformation vibration is suitably realized, and the driven part is suitably rotated. The

  In this embodiment, when a single coil unit is used, two or more signals may be superimposed in order to drive two or more axes. In other words, the drive signal responsible for the axis around one direction and the two drive signals responsible for the axis around the other direction are superimposed. Therefore, a drive signal in which two signals are superimposed may be supplied to the coil unit.

In the other form 1 of the present embodiment, the coil portion is disposed away from the driven portion and is disposed on the second base portion. In other words, the coil part is arranged at a position shifted from the place where the driven part is arranged in a predetermined direction (other direction, an X-axis direction described later). More specifically, the coil part is arranged on the first elastic part so that the center of the coil part is arranged at a position shifted in a predetermined direction from the place where the center of the driven part is arranged.

  The rotational force of the coil portion generated by the Lorentz force becomes a force for twisting the coil portion about the axis along the Y-axis direction, and this torsional vibration generates a stationary wave-like deformation vibration. In other words, the electromagnetic force generated by the coil portion generates deformation waves having a standing wave shape with the second base portion and the first elastic portion. This standing wave-like deformation vibration causes the driven part to resonate and rotate.

  At this time, the rotation axis of the coil part along the Y-axis direction is different from the rotation axis of the driven part along the Y-axis direction. Specifically, the rotation axis of the coil unit 141 along the Y-axis direction exists at a position shifted by a predetermined distance in the X-axis direction with reference to the rotation axis of the mirror along the Y-axis direction. For this reason, the rotation of the coil portion 141 having the axis along the Y-axis direction as the rotation axis does not directly rotate the driven portion about the axis along the Y-axis direction as the rotation axis.

  The standing wave deformation vibration (standing wave deformation vibration with the second base portion and the first elastic portion) will be described. In the driving device of the present embodiment, due to the periodic electromagnetic excitation force generated by the coil portion, the spring elasticity and mass of each portion (including the first elastic portion and the second base portion (including the driven portion and the second elastic portion)). Standing wave-like resonance occurs. In this resonance, the first elastic part a, the second base part (including the driven part and the second elastic part), and the first elastic part b are connected along the other direction, like the double mode of the string. Shows deformed appearance.

  Furthermore, in the drive device of the present embodiment, stationary wave-like deformation vibrations of the second base part and the first elastic part due to the electromagnetic excitation force (and torsional vibration caused by this) generated by the coil part, that is, the first In the case where the first elastic part a, the second base part (including the driven part and the second elastic part), and the first elastic part b are connected and deformed into a standing wave shape along other directions and deformed, the coil part The rotation center of is at the position corresponding to the node. However, the position of the section here is not a strict meaning and may be interpreted as a position close to the section. At this time, the coil portion performs a rotational motion with an axis including the rotation center (an axis parallel to the extending direction of the second elastic portion = a Y-axis direction described later) as the rotation axis. Therefore, the driving force by the electromagnetic force generated by the coil portion is preferably a rotational force having an axis including the rotation center (an axis parallel to the extending direction of the second elastic portion = a Y-axis direction described later) as the rotation axis.

  Then, the resonance can be suitably increased by matching the vibration form caused by the resonance of the coil part (on the second base) with the form of the excitation force. Thus, if a rotational force (and torsional vibration due to the rotational force) is applied to the coil portion, the resonance is preferably increased, and the steady-wave deformation vibration of the second base portion and the first elastic portion is increased. As a result, it is possible to obtain a larger rotational amplitude of the driven part with a smaller driving force by resonance with the driven part (stationary wave-like deformation vibration). However, the above-described matching of the vibration form of the coil portion and the form of the excitation force does not have to be exact coincidence, and the effect of increasing the amplitude even if the rotation axis is deviated, for example, rotational movement and translational movement are mixed. Can be obtained. Therefore, in consideration of the balance with other design conditions, it is sufficient to appropriately adjust the match between the vibration mode and the excitation force mode.

In addition, the above-described vibration form of the coil portion and the form of the excitation force do not necessarily have to be matched.
In this case, driving with leakage of driving force (in other words, force that works in an unintended direction)
You may drive by the force (nondirectional vibration) which does not limit the direction of force as shown by patent document 3. FIG.

In another aspect 2 of the present embodiment,
The driven part is rotated by the electrostatic attractive force caused by the charge on the electrode. In other words, the driving force for rotating the driven part is an electrostatic attractive force generated between the movable electrode and the fixed electrode.

  In another aspect 3 of the present embodiment, the driven part is rotated by the deformation force generated by the piezoelectric body. In other words, the driving force for rotating the driven part is a displacement force due to expansion and contraction of the piezoelectric body.

  In the other aspect 4 of the present embodiment, the second base portion is not significantly deformed in the standing wave-like deformation vibration with the second base portion and the first elastic portion. In other words, it is the first elastic part that is mainly deformed in the standing wave-like deformation vibration of the second base part and the first elastic part.

Such an operation and other advantages of the present embodiment will be clarified from examples described below.
As described above, according to the drive device of this embodiment,
A shaft that connects the first base portion, the second base portion supported by the first base portion, the first base portion and the second base portion, and the second base portion along another direction. A first elastic part having elasticity such that the rotation part is rotated, a rotatable driven part, the second base part and the driven part are connected, and the driven part is connected to the other direction. Comprises a second elastic portion having elasticity that rotates about an axis along a different direction, and a drive source portion that applies vibration to the second base portion, and the drive source portion is the other The first elastic part a, the second base part (including the second elastic part and the driven part), and the first elastic part b are connected along the direction of the line to deform and vibrate in a standing wave shape, and the deformation vibration resonates. A periodic excitation force is applied so that the The moving part resonates with the axis along the one direction as a central axis, and the resonance frequency of the driven part is shifted by the stationary wave-like deformation vibration, and the resonance frequency of the driven part is Unlike the resonance frequency determined by the part and the second elastic part, the driven member rotates at a larger rotation angle, and a driving device with higher efficiency and lower power consumption can be provided.

Embodiments of the drive device will be described with reference to the drawings. In the first to fifth embodiments, an example in which the driving device is applied to a MEMS mirror driving device will be described.
(1) First Example First, a first example of a MEMS mirror driving device will be described with reference to FIGS.
(1-1) Basic configuration

  With reference to FIG. 1, a basic configuration of the MEMS mirror driving device 100 of the first embodiment will be described. FIG. 1 is a plan view conceptually showing the basic structure of the MEMS mirror driving device 100 of the first embodiment.

  As shown in FIG. 1, the MEMS mirror driving device 100 of the first embodiment includes a first base portion 110-1, a first elastic portion 120 including first elastic portions 120a-1 and 120b-1, and an upper side 110. -2ou, vertical side 110-2a, vertical side 110-2b, lower side 110-2od, second base portion 110-2, and second elastic portions 120a-2 and 120b-2, second elastic portion 120-2. And a mirror 130, a coil part 141, and a drive source part 140 including magnetic poles 142a to hh as magnetic field applying parts.

  The first base part 110-1 has a frame shape with a gap inside. That is, the first base portion 110-1 has two sides extending in the Y-axis direction in FIG. 1 and two sides extending in the X-axis direction in FIG. It has a frame shape having a gap surrounded by one side and two sides extending in the X-axis direction. In the example shown in FIG. 1, the first base portion 110-1 has a rectangular shape, but is not limited to this, for example, other shapes (for example, a rectangular shape such as a square or a circular shape). Or the like. The first base portion 110-1 is a structure that is the basis of the MEMS mirror driving device 100 of the first embodiment, and is preferably fixed to a substrate or a support member (not shown).

  As described above, FIG. 1 shows an example in which the first base portion 110-1 has a frame shape, but it goes without saying that it may have other shapes. For example, the first base portion 110-1 may have a U-shape in which a part of the side is an opening. Alternatively, for example, the first base portion 110-1 may have a box shape with a gap inside. That is, the first base portion 110-1 is orthogonal to the two surfaces distributed on the plane defined by the X axis and the Y axis, and the X axis and the Z axis (not shown) (that is, both the X axis and the Y axis). And two surfaces distributed on a plane defined by a Y-axis and a Z-axis (not shown) and surrounded by these six surfaces. It may have a box shape with a gap. Or you may change the shape of the 1st base part 110-1 arbitrarily suitably according to the aspect in which the mirror 130 is arrange | positioned.

  The first elastic portion 120a-1 is a member having elasticity such as a spring made of, for example, silicon, copper alloy, iron alloy, other metal, resin, or the like. The first elastic portion 120a-1 is disposed so as to extend in the direction of the X axis in FIG. In other words, the first elastic portion 120a-1 has a shape having a long side extending in the X-axis direction and a short side extending in the Y-axis direction. However, the first elastic portion 120a-1 has a shape having a short side extending in the X-axis direction and a long side extending in the Y-axis direction according to the setting state of the resonance frequency described later. Or may have any other shape. Moreover, you may be comprised with the some elastic material. One end of the first elastic portion 120a-1 is connected to the inner side of the first base portion 110-1. The other end portion of the first elastic portion 120a-1 is a connecting portion 110 on the outer side of the second base portion 110-2 that faces the inner side of the first base portion 110-1 along the X-axis direction. -2a.

  The first elastic portion 120b-1 is a member having elasticity such as a spring made of, for example, silicon, copper alloy, iron alloy, other metal, resin, or the like. The first elastic part 120b-1 is arranged so as to extend in the X-axis direction in FIG. In other words, the first elastic part 120b-1 has a shape having a long side extending in the X-axis direction and a short side extending in the Y-axis direction. However, the first elastic portion 120b-1 has a shape having a short side extending in the X-axis direction and a long side extending in the Y-axis direction according to the setting state of the resonance frequency described later. Or may have any other shape. Moreover, you may be comprised with the some elastic material. One end of the first elastic portion 120b-1 is connected to the frame portion 110-2h of the second base portion 110-2 along the X-axis direction. The other end of the first elastic portion 120b-1 is connected to the inner side of the first base portion 110-1 along the X-axis direction.

  The 2nd base part 110-2 has a frame shape provided with a space inside. That is, it has an upper side 110-2ou parallel to the X-axis in FIG. 1, a vertical side 110-2a, a lower side 110-2od parallel to the X-axis direction, and a vertical side 110-2b. The four sides are connected to each other. The first elastic portion 120a-1 is connected to the connecting portion of the second base portion 110-2 and the vertical side 110-2a, and the first elastic portion 120b-1 is connected to the central portion of the vertical side 110-2b. .

  The second base portion 110-2 has a vertically symmetrical shape with the center line of the first elastic portion 120-1 as the axis of symmetry. However, the 2nd base part 110-2 is not limited to these, For example, it has other shapes (For example, a square, a rhombus, a hexagon, an octagon, a polygon, a circle, an ellipse shape, etc.). It may be. Needless to say, it does not have to be symmetrical.

  The sides (upper side 110-2ou, vertical side 110-2a, vertical side 110-2b, lower side 110-2od) constituting the second base portion 110-2 may have the same thickness, or may have different thicknesses depending on the side. It may be good or may be reinforced with ribs or the like. In order to suitably realize a stationary wave-like deformation vibration between the second base portion and the first elastic portion, which will be described in detail in the operation section, the side rigidity may be varied. Specifically, it is preferable to make the rigidity of the side along the direction of the Y-axis higher than the rigidity of the side along the direction of the X-axis. The rigidity here is not a mere hardness (Young's modulus), In other words, the resonance frequency of the deformation vibration of the second base portion 110-2 along the Y-axis direction is the resonance frequency of the deformation vibration of the second base portion 110-2 along the X-axis direction. It should be interpreted as meaning higher than the frequency.

  The second base part 110-2 is arranged to be suspended or supported by the first elastic parts 120a-1 and 120b-1 in the space inside the first base part 110-1. The second base portion 110-2 is configured to rotate about the direction along the X axis as a rotation axis by the elasticity of the first elastic portions 120a-1 and 120b-1. In other words, it is configured to rotate around an axis parallel to the X axis.

 The second elastic portion 120a-2 is a member having elasticity such as a spring made of silicon, copper alloy, iron alloy, other metal, resin, or the like. The 2nd elastic part 120a-2 is arrange | positioned so that it may extend | stretch in the direction of the Y-axis in FIG. In other words, the second elastic portion 120a-2 has a shape having a long side extending in the Y-axis direction and a short side extending in the X-axis direction. However, the second elastic portion 120a-2 has a shape having a short side extending in the direction of the Y-axis and a length extending in the direction of the X-axis, depending on the setting state of the resonance frequency described later. Also good. One end of the second elastic portion 120a-2 is connected to the inner side of the upper side 110-2ou of the second base portion 110-2. The other end portion of the second elastic portion 120a-2 is connected to one end portion of the mirror 130 facing the inner side of the second base portion 110-2 along the Y-axis direction.

  The second elastic portion 120b-2 is a member having elasticity such as a spring made of silicon, copper alloy, iron-based alloy, other metal, resin, or the like. The second elastic portion 120b-2 is disposed so as to extend in the direction of the Y axis in FIG. In other words, the second elastic portion 120b-2 has a shape having a long side extending in the Y-axis direction and a short side extending in the X-axis direction. However, the second elastic portion 120b-2 has a shape that has a short side that extends in the direction of the Y axis and a length that extends in the direction of the X axis according to the setting state of the resonance frequency described later. Also good. One end of the second elastic portion 120b-2 is connected to the inside of the lower side 110-2od of the second base portion 110-2 along the direction of the Y axis. The other end of the second elastic portion 120b-2 is the mirror 130 (on the side where 120a-2 is not connected) facing the inner side of the second base portion 110-2 along the Y-axis direction. Connected to the end.

  The mirror 130 is arranged to be suspended or supported by the second elastic portions 120a-2 and 120b-2 in the gap inside the second base portion 110-2. The mirror 130 is configured to rotate about the axis along the Y-axis direction as a rotation axis by the elasticity of the second elastic portions 120a-2 and 120b-2. In other words, it is configured to rotate around an axis parallel to the Y axis.

  The mirror 130 may be formed by plating, metal deposition, or the like on a base material such as silicon, copper alloy, iron-based alloy, other metal, resin, or a metal mirror, glass mirror, or the like. Good.

  The drive source unit 140 causes the coil unit 141 to generate vibration necessary for rotating the mirror 130 about the axis along the Y-axis direction as a central axis. That is, as will be described later, the first elastic portion 120a-1, the second base portion 110-2 (including the mirror 130, the second elastic portions 120a-2, 120b-2), and the first elastic portion 120b-1. Thus, an exciting force for resonating in a standing wave shape (a stationary wave-like deformation vibration described later) can be applied. Moreover, you may be comprised so that force can be applied with respect to the 2nd base part 110-2. Specifically, by applying a twisting force around the axis along the X axis to the second base portion 110-2, a force for rotating the second base portion 110-2 and the mirror 130 connected thereto may be applied. Good.

  More specifically, the drive source unit 140 is a drive source unit that applies a force due to an electromagnetic force, and forms a coil unit 141 and a magnetic field applying unit fixed to the first base unit 110-1. 142a, 142b, 142c, 142d, 142e, 142f, 142g, and 142h. In this case, a desired current is applied to the coil unit 141 at a desired timing from a drive source unit control circuit (not shown), and electromagnetic interaction occurs between the coil unit 141 and the magnetic poles 142a to 142h. As a result, electromagnetic force due to electromagnetic interaction is generated. This electromagnetic force is transmitted as vibration or torsional force to the coil part 141, the first elastic part 120 (120a-1, 120b-1), the second base part 110-2, and the mirror 130, and rotates the mirror 130.

  The coil unit 141 includes a winding made of, for example, a material having relatively high conductivity (for example, gold, copper, aluminum, or the like). It may be formed by plating or vapor deposition on the frame part 110-2h of the second base part 110-2, or may be formed by etching or the like. In the first embodiment, the coil portion 141 has a rectangular shape. However, the coil part 141 may have an arbitrary shape (for example, a square, a rhombus, a parallelogram, a circle, an ellipse, a polygon, or any other loop shape).

  The coil part 141 is arrange | positioned on the 2nd base part 110-2. That is, the coil unit 141 is disposed around the mirror 130.

  The magnetic field applying unit includes a permanent magnet and a yoke (magnetic material such as iron) that induces a magnetic field, and applies a magnetic field to the coil unit 141 from the magnetic poles 142a to 142h. The magnetic poles 142 a to 142 f are arranged around the coil portion 141. The magnetic pole 142g and the magnetic pole 142h are disposed in the gap inside the coil portion 141.

  The magnetic poles 142a and 142b are arranged so as to sandwich the coil part 141 along the Y-axis direction. The description will be made using an example in which the magnetic pole 142a is on the magnetic field exit side (N pole) and the magnetic pole 142b is on the magnetic field entrance side (S pole). Needless to say, the exit side (N pole) and the incident side (S pole) ) May be replaced. Here, the magnetic pole 142g and the magnetic pole 142h serve as intermediate yokes and serve to relay magnetic flux. Similarly, the magnetic poles 142c, 142d, 142e, and 142f are arranged so as to sandwich the coil portion 141 along the X-axis direction. The description will be made using an example in which the magnetic poles 142c and 142d are on the magnetic field exit side (N pole) and the magnetic poles 142e and 142f are on the magnetic field entrance side (S pole). It does not matter if the side (S pole) is switched. Further, the number of magnetic poles may be set as appropriate without being limited to the above numerical values. An electromagnet may be used instead of the permanent magnet. Further, there may be no intermediate yoke.

Next, a configuration including the drive source unit 140 will be described with reference to FIG.
FIG. 2 shows a first elastic part 120a-1, a second base part 110-2 (including a mirror 130, second elastic parts 120a-2 and 120b-2, a coil part 141), a first elastic part 120b-1, and It is the figure which looked at the magnetic poles 142c-142e from the side.

As shown in FIG. 2, the first elastic part 120a-1, the second base part 110-2 (including the mirror 130, the second elastic parts 120a-2, 120b-2, and the coil part 141), the first elastic part 120b. −1 are continuous and vibrate in a standing wave shape (resonance). The vibration state at this time is such that a node appears at a position corresponding to the center of the mirror 130, that is, at the connection portion with the second elastic portion 110-2 near the center of the second base portion 110-2, and the first elastic portion 120a. -1 and the second base portion have a belly, and a belly appears at the connection portion between the first elastic portion 120b-1 and the second base portion. The rigidity, mass, and the like of each part are adjusted so that such a kneaded standing wave-like vibration state appears. Since this resonance will be described in detail as a standing-wave-like deformation vibration with the second base portion and the first elastic portion in the section of operation, only the outline thereof will be described here.
(1-2) Operation of MEMS mirror driving device

  Subsequently, an operation mode (specifically, an operation mode of rotating the mirror 130) of the MEMS mirror driving device 100 of the first embodiment will be described with reference to FIGS.

  First, the rotation about the axis along the X-axis direction of the mirror 130 as a central axis will be described with reference to FIG. During operation of the MEMS mirror driving apparatus 100 of the first embodiment, a desired current is applied to the coil unit 141 at a desired timing from a drive source unit control circuit (not shown), and the coil unit 141 and the magnetic poles 142a and 142b Electromagnetic interaction occurs between the two. As a result, electromagnetic force due to electromagnetic interaction is generated. This electromagnetic force becomes a force that twists the coil part 141 about the axis along the X-axis direction as a center axis, and rotates the second base part 110-2 around the axis along the X-axis direction as a center axis. Therefore, the mirror 130 connected to the second base portion is also rotated about the axis along the X-axis direction as the central axis.

  Here, the direction of the electromagnetic force due to the electromagnetic interaction between the coil portion 141 and the magnetic pole 142a is from the back side (the back side of the paper) to the near side (the front side of the paper) in FIG. The direction of the electromagnetic force by the electromagnetic interaction between the coil part 141 and the magnetic pole 142b is from the front side to the back side in FIG. As a result, the electromagnetic force rotates the coil unit 141 with the extending direction (the direction along the X axis) of the first elastic units 120a-1 and 120b-1 as the rotation axis direction. As a result, the second base portion 110-2 to which the coil portion 141 is attached rotates about the axis along the X-axis direction as a central axis, and the mirror 130 supported by the second base portion 110-2 also includes the above-described mirror 130. It rotates with the axis along the X-axis direction as the central axis.

  Note that the second base portion 110-2 (including the second elastic portions 120a-2 and 120b-2 and the mirror 130) may repeatedly rotate at a frequency lower or higher than a mirror resonance frequency described later. For example, when the MEMS mirror driving device 100 of the first embodiment is applied to a display (or a head mounted display), the second base portion 110-2 (second elastic portions 120a-2 and 120b-2 and the mirror 130). May repeat the rotation operation at a frequency (for example, 60 Hz) corresponding to the scanning period or frame rate of the display, for example.

  Alternatively, the second base portion 110-2 (including the second elastic portions 120a-2 and 120b-2 and the mirror 130) is a suspended portion such as the second base portion 110-2 and the mirror 130, and the first elastic portion 120. The rotation operation at a more specific resonance frequency may be repeated. Specifically, the second base portion 110-2 (including the second elastic portions 120a-2 and 120b-2 and the mirror 130) includes the second base portion 110-2 and the suspended portion such as the coil portion 141 and the second base portion 110-2. You may rotate so that it may resonate with the resonance frequency defined according to 1 elastic part 120a-1 and 120b-1. For example, the moment of inertia around the axis along the X axis of the second base portion 110-2 (including the mirror 130) (more specifically, the second elastic portion 120a provided in the second base portion 110-2). -2 and 120b-2 and the second base portion 110-2 including the respective masses of the mirror 130, the suspension moment portion consisting of the entire system, ie, the inertia moment about the axis along the X axis) is I1; If the torsion spring constant when the first elastic parts 120a-1 and 120b-1 are regarded as one spring is k1, the second base part 110-2 (second elastic parts 120a-2, 120b- 2 and the mirror 130) is a resonance frequency specified by (1 / (2π)) × √ (k1 / I1) or near the resonance frequency (or (1 / (2π)) × √ (k1 / I1) N times (where N is 1 or more) To resonate at an integer) the resonant frequency of), it may be rotated about axis an axis along the direction of the X axis.

  Next, with reference to FIG. 1 and FIG. 2, rotation about the axis along the Y-axis direction of the mirror 130 as a central axis will be described. During the operation of the MEMS mirror driving device 100 of the first embodiment, a desired control current is applied to the coil unit 141 at a desired timing from a drive source unit control circuit (not shown).

  The control current includes a current component for rotating the mirror 130 about the axis along the Y-axis direction as a rotation axis. In the first embodiment, the mirror 130 has a resonance frequency determined by the mirror 130 and the second elastic portions 120a-2 and 120b-2 with a standing wave shape of the second base portion 110-2 and the first elastic portion 120-1 described later. Using the deformation vibration, the axis along the Y-axis direction is rotated about the axis of rotation so as to resonate at the transitioned frequency. In other words, the resonance rotation is performed at a frequency different from the resonance frequency determined by the mirror 130 and the second elastic portions 120a-2 and 120b-2.

  In this embodiment, when a single coil portion is used, two or more signals may be superimposed in order to drive two or more axes. That is, a signal in which two signals of a current component responsible for rotation around the axis along the X-axis direction and a current component responsible for rotation around the axis along the Y-axis direction are superimposed on the drive coil 141 may be applied.

  Here, as shown in FIG. 1, a control current flowing in the counterclockwise direction is supplied to the coil unit 141, and a magnetic field from the magnetic poles 142c and 142d toward the magnetic poles 142e and 142f is applied to the coil unit 141. . By applying a current to the coil unit 141, electromagnetic interaction occurs between the coil unit 141 and the magnetic pole 142c, the magnetic pole 142d, the magnetic pole 142e, and the magnetic pole 142f.

  The direction of electromagnetic force due to electromagnetic interaction between the coil portion 141 and the magnetic poles 142c and 142d is from the back side (front side of the paper) to the labor side (back side of the paper) in FIG. The direction of the electromagnetic force due to the electromagnetic interaction between the coil portion 141 and the magnetic pole 142d and the magnetic pole 142e is from the front side to the back side in FIG.

  In other words, as shown in FIG. 2, the direction of the electromagnetic force due to the electromagnetic interaction between the coil portion 141a, the magnetic pole 142c, and the magnetic pole 142d is from the lower side to the upper side in FIG. The direction of the electromagnetic force due to the electromagnetic interaction between the coil portion 141b, the magnetic pole 142e, and the magnetic pole 142f is from the upper side to the lower side in FIG. That is, electromagnetic forces in directions different from each other are generated on the two long sides of the coil portion 141 facing in the X-axis direction. In other words, an electromagnetic force serving as a couple is generated on the two long sides 141a and 141b of the coil portion 141 facing in the X-axis direction. Therefore, the coil part 141 rotates in the clockwise direction in FIG.

  On the other hand, since the control current is an alternating current, a control current flowing in the clockwise direction is supplied to the coil unit 141 after a half cycle. Accordingly, the coil portion 141 rotates in the clockwise direction in FIG. As a result, the coil unit 141 repeatedly rotates about the axis along the Y-axis direction as a rotation axis.

  The repeated rotation of the coil 141 as described above is transmitted to the second base portion 110-2 and the first elastic portion 120-1 as torsional vibration of the coil portion 141 with the axis along the Y-axis direction as the central axis. A stationary wave-like deformation vibration of the second base portion and the first elastic portion is generated.

  Next, the standing-wave deformation vibrations of the second base portion and the first elastic portion will be described with reference to FIG. The first elastic part 120a-1, the second base part 110-2 (including the second elastic parts 120a-2 and 120b-2 and the mirror 130), and the first elastic part 120b are generated by the exciting force generated by the coil part 141. -1 are continuous, deform and vibrate in a standing wave shape along other directions, and become resonance. In other words, the first elastic portion 120a-1, the second base portion 110-2 (including the second elastic portions 120a-2 and 120b-2 and the mirror 130), and the first elastic portion 120b-1 are connected to form an X axis. It vibrates in a deformed state like the double string mode along the direction. That is, a part of the first elastic portion 120a-1, the second base portion 110-2 (including the second elastic portions 120a-2 and 120b-2 and the mirror 130), and the first elastic portion 120b-1 are in a standing wave shape. The deformation state is such that the deformation vibration becomes the antinode and the other part becomes a node of the deformation wave having a standing wave shape.

  In the above-described stationary wave-like deformation vibration, a node appears at the center of the coil portion 141. A node appears at the connection portion of the second elastic part of the upper side 110-2ou and the lower side 110-2od of the second base part 110-2, in other words, at the position of the rotation center of the mirror 130. A node appears at the center of the second base part 110-2, a belly appears at the connection between the right end of the first elastic part 120a-1 and the second base part 110-2a, and the first elastic part 120b-1 A belly appears at the connection between the left end and the second base portion 110-2b. That is, the center of the coil portion 141 is located at the node position in the standing wave.

  Here, the force for rotationally resonating the mirror 130 with the axis along the Y-axis direction as the rotation axis is not an aspect of directly rotating the mirror 130, but the coil portion 141 serving as the drive source portion is subjected to the deformation of a standing wave. The mirror 130 is driven to resonate by applying an excitation force as an energy source.

On the other hand, as described above, the center of rotation of the mirror 130 is at the position of the node. For this reason, as shown in FIG. 2, the movement is small in the vertical direction (direction along the Z axis), and a rotational movement around the axis along the Y axis direction is generated so that the rotation can be enjoyed suitably. . The above-described deformation vibration shows a so-called standing wave-like deformation state, and the positions of the antinodes and nodes are substantially fixed.
However, the above-described mirror 130 or coil part 141 being in the position of the node does not mean that the mirror 130 or the coil part 141 is strictly located, and it may be interpreted that the mirror 130 or the coil part 141 is in a position close to the node. It is better to grasp that the closer to the knot, the more efficient the rotation.

  Such a standing wave-like deformation of the first elastic part 120a-1, the second base part 110-2 (including the second elastic parts 120a-2 and 120b-2 and the mirror 130) and the first elastic part 120b-1. Due to the vibration, the mirror 130 is rotated.

  The rotational resonance of the mirror 130 and the stationary wave-like deformation vibration of the second base portion and the first elastic portion are generated at the same frequency, but the frequency is different from the resonance frequency determined by the mirror 130 and the second elastic portion. . That is, the resonance frequency of the mirror 130 is changed by a standing wave-like deformation vibration of the second base portion and the first elastic portion. As a result, the mirror 130 resonates at a frequency different from the resonance frequency determined by the mirror 130 and the second elastic portion. The resonance frequency of the mirror 130 at this time is typically higher than the resonance frequency determined by the mirror 130 and the second elastic part. Further, at this time, the rotation angle of the mirror 130 becomes larger than that in the case where the frequency is not shifted by the stationary wave-like deformation vibration.

  In order to realize the above-described standing-wave deformation vibration, the first elastic part 120a-1, the second base part 110-2 (including the second elastic parts 120a-2 and 120b-2 and the mirror 130), and the first The rigidity, mass, length, etc. of the elastic part 120b-1 are adjusted. Specifically, the length, cross-sectional shape, rigidity, shape of the second base part 110-2, mass, rigidity, shape of the coil part 141, mass, rigidity, etc. may be adjusted. By adjusting these, the position of the node, the antinode, and the resonance frequency become appropriate, the above-described stationary wave-like deformation vibration is suitably realized, and the preferred rotation of the mirror 130 is realized.

  Here, a method for adjusting the resonance frequency in the standing-wave-like deformation vibration will be described in more detail with reference to FIGS. In recent years, computing technology has developed, and simulations can be performed easily on a personal computer without trial production, and the values of the trial production and simulation match with high accuracy. Here, as an example of simulation by a personal computer, a method for adjusting a resonance frequency and a method for adjusting rigidity in a standing wave-like deformation vibration will be described. The resonance frequency of the target mirror 130 is about 25 kHz.

(Adjustment 1)
First, the resonance frequency of the mirror 130 determined by the mirror 130 and the second elastic part 120-2 is calculated. The mirror 130, the second elastic part (120a-2, 120b-2), the second base part 110-2, and the coil part 141 are equipped, and the thickness, diameter, length, width, etc. are appropriately adjusted. Then, complete fixation is input as the boundary condition of the second base unit 110-2. If eigenvalue analysis (resonance frequency analysis) is performed with simulation software in this state, the resonance frequency of the mirror 130 determined by the mirror 130 and the second elastic portion 120-2 is calculated. At this time, the dimensions of each part are determined (by repetitive calculation) so that the resonance frequency of the mirror 130 in the rotational direction along the Y-axis direction is 25 kH.

(Adjustment 2)
Next, the first elastic portions 120a-1 and 120b-1 and the first base portion 110-1 are additionally equipped, and the thickness, length, width, etc. are appropriately adjusted. In this state, when complete fixing is input as the boundary condition of the first base part-1, the first elastic part 120a-1, the second base part 110-2 (second elastic parts 120a-2, 120b-2, and mirrors). 130), and the resonance frequency and resonance mode of the standing-wave-like resonance (combined rotational motion and translational motion) of the first elastic portion 120b-1. The dimensions (thickness, length, width, size) of each part are adjusted so that the Nth-order resonance mode at this time becomes a deformed state like the double-string mode as shown in FIG. Further, it is preferable to finely adjust each part so that a node appears at a position corresponding to the rotation axis of the mirror 130 (rotation center of the mirror) and a position of the rotation center of the coil unit 141.

  If the resonance frequency in the above-described vibration state is calculated to be 25.000 kHz, this state indicates that the frequency of the standing-wave-like deformation vibration is the resonance frequency of the mirror 130 (mirror 130 (driven portion) and the second elastic portion 120). The condition is adjusted to match.

(Adjustment 3)
However, the above-mentioned state (25.000 kHz) is not the best state in this embodiment. Next, for example, a case where the thickness of the upper side 110-2ou and the lower side 110-2od of the second base part 110-2 is slightly increased is assumed. Since the spring rigidity increases in proportion to the cube of the thickness and the mass is proportional to the thickness of the first power (in other words, the rigidity increases but the mass does not increase so much), the resonance of the system including the second base portion 110 The frequency increases, and the resonance frequency of the standing wave-like deformation vibration increases.

Then, it is assumed that the calculation result by the simulation is changed to 25.25 KHz (frequency of the standing wave-like deformation vibration = frequency of the driven part). The concept of the vibration state at this time is shown in FIG. The amplitude of the standing wave-like deformation vibration decreases and the rotation angle of the mirror increases. At this time, the mirror 130 resonates at a frequency different from the frequency (25.000 kHz) determined by the mirror 130 and the second elastic portion 120-2.
(Resonant frequency of mirror is changed by standing wave deformation vibration)

  On the contrary, when the same simulation is performed with the thickness of the upper side 110-2ou and the lower side 110-2od of the second base part 110-2 being reduced, the resonance frequency of the standing wave-like deformation vibration is lowered 24. .75 KH, the amplitude of the standing-wave deformation vibration is increased, and the touch angle of the mirror 130 is decreased.

  Thus, in this embodiment, the mirror 130 resonates at a resonance frequency different from the resonance frequency determined by the mirror 130 and the second elastic portion 120-2. In other words, the resonance frequency of the mirror 130 is shifted by the standing wave-like deformation vibration.

  Also, according to various aspects of the calculation, typically, the mirror rotation angle increases when the resonance frequency of the mirror 130 is shifted to a higher frequency by a standing wave-like deformation vibration.

  When the rotation direction of the coil portion 141 and the rotation direction of the mirror 130 are the same (referred to as in-phase), the above transition frequency (deviation) tends to increase, and the deviation is 1% to 10%. There is an example that becomes a degree. As shown in FIG. 4, when the movements of the second base unit 110-2 and the mirror 130 are in opposite directions (referred to as reverse phase), the above-described deviation is small, and the deviation is from 0.03% to 2%. There is an example which becomes about%.

  Or, as an example, when the vibration mode of the standing wave-shaped deformation vibration is set to a lower mode, that is, a vibration mode close to the double mode of the string, the above transition frequency (deviation) tends to increase. There have been confirmed examples of up to 30%.

  In addition, contrary to the above-described typical example, there is also an example in which it is preferable that the resonance frequency of the mirror 130 is changed to a low level by a standing wave-like deformation vibration. It should be added that the frequency may be set lower than the frequency determined by the unit 120-2.

  Here, regarding the resonance frequency of the mirror 130, the different resonance frequencies (frequency deviations) will be mentioned. A structure composed of silicon such as MEMS and a metal spring has a small attenuation as a material, and the resonance peak in the frequency characteristic diagram has a sharp and steep shape. A typical numerical value representing the sharpness of the resonance peak is a Q value. The MEMS and metal have a large Q value, typically about 1500. Here, the deviation of the resonance frequency will be described using the Q value.

  The definition of the Q value is as follows: ω is the resonance frequency at the resonance peak, ω1 is the frequency at which the vibration energy is half the resonance peak on the frequency side lower than ω, and ω2 is the half value of the resonance peak on the frequency side higher than ω. Q value is represented by Q = ω / (ω2−ω1). If the above ω = 25000 Hz and Q = 1500 are substituted for the deformation, ω2−ω1 = 25000/1500 = 16.67 Hz. Further, due to the symmetry of the resonance peak, the difference between the resonance peak frequency ω and ω1 (ω2) is 16.67 / 2 = 8.34 Hz. That is, in the frequency characteristics of the drive device, when the excitation resonance frequency is 8.34 Hz away from the resonance peak frequency ω, the resonance energy of the system is reduced to half (the rotation angle is √ (0.5)). 8.34 Hz is 0.0334% ≈0.03% of 25 kHz. Accordingly, the resonance energy is halved by the deviation of the resonance frequency (peak frequency) of 0.03%. Therefore, it can be considered that the difference of 0.03% in the resonance frequency is a sufficient difference. The above-described example is a consideration example when the resonance energy is halved, and the present invention is not limited to this calculation, and the different resonance frequencies may be arbitrarily determined.

  As described above, the MEMS mirror driving apparatus 100 according to the first embodiment can rotate the mirror 130 with the axis along the X-axis direction as the rotation axis, and at the same time, the mirror with the axis along the Y-axis direction as the rotation axis. 130 can be resonantly rotated. That is, the MEMS mirror driving device 100 of the first embodiment can perform biaxial driving.

  Here, the force for rotationally resonating the mirror 130 with the axis along the Y-axis direction as the rotation axis is not an aspect of directly rotating the mirror 130, but is applied to the coil unit 141 as an energy source of deformation waves in the form of standing waves. By applying force, the mirror 130 is driven to resonate.

In particular, the resonance frequency of the mirror 130 is different from the resonance frequency determined by the mirror 130 and the second elastic portion 120-2. The resonance frequency of the mirror 130 is shifted (typically a high frequency) by the stationary wave-like deformation vibration of the second base portion 110-2 and the first elastic portion 120-1, and the resonance is accurately synthesized. Thus, the driven device can be rotated at a larger rotation angle to provide a driving device with higher efficiency and lower power consumption.
(2) Second Embodiment First, a second embodiment of the MEMS mirror driving device will be described with reference to FIGS.
(2-1) Basic configuration

  With reference to FIG. 5, the basic configuration of the MEMS mirror driving device 101 of the second embodiment will be described. FIG. 5 is a plan view conceptually showing the basic structure of the MEMS mirror driving device 101 of the second embodiment.

  As shown in FIG. 5, the MEMS mirror driving device 101 according to the second embodiment includes a first base portion 110-1, a first elastic portion 120 including first elastic portions 120 a-1 and 120 b-1, and an upper side 110. -2ou, a vertical side 110-2a, a lower side 110-2od, a second base part 110-2 comprising a frame part 110-2h, and a second elastic part 120-2 comprising a second elastic part 120a-2 and 120b-2. And a mirror 130, a coil unit 141, and a drive source unit 140 including magnetic poles 142a to 142e as magnetic field applying units.

  The first base part 110-1 has a frame shape with a gap inside. That is, the first base portion 110-1 has two sides extending in the Y-axis direction in FIG. 5 and two sides extending in the X-axis direction in FIG. 5, and extends in the Y-axis direction. It has a frame shape having a gap surrounded by one side and two sides extending in the X-axis direction. In the example shown in FIG. 5, the first base portion 110-1 has a rectangular shape, but is not limited to this, for example, other shapes (for example, a rectangular shape such as a square or a circular shape). Or the like. The first base portion 110-1 is a structure that is the basis of the MEMS mirror driving device 101 of the second embodiment, and is preferably fixed to a substrate or a support member (not shown).

  As described above, FIG. 5 shows an example in which the first base portion 110-1 has a frame shape, but it goes without saying that the first base portion 110-1 may have other shapes. For example, the first base portion 110-1 may have a U-shape in which a part of the side is an opening. Alternatively, for example, the first base portion 110-1 may have a box shape with a gap inside. That is, the first base portion 110-1 is orthogonal to the two surfaces distributed on the plane defined by the X axis and the Y axis, and the X axis and the Z axis (not shown) (that is, both the X axis and the Y axis). And two surfaces distributed on a plane defined by a Y-axis and a Z-axis (not shown) and surrounded by these six surfaces. It may have a box shape with a gap. Or you may change the shape of the 1st base part 110-1 arbitrarily suitably according to the aspect in which the mirror 130 is arrange | positioned.

  The first elastic portion 120a-1 is a member having elasticity such as a spring made of, for example, silicon, copper alloy, iron alloy, other metal, resin, or the like. The first elastic part 120a-1 is arranged so as to extend in the X-axis direction in FIG. In other words, the first elastic portion 120a-1 has a shape having a long side extending in the X-axis direction and a short side extending in the Y-axis direction. However, the first elastic portion 120a-1 has a shape having a short side extending in the X-axis direction and a long side extending in the Y-axis direction according to the setting state of the resonance frequency described later. Or may have any other shape. One end of the first elastic portion 120a-1 is connected to the inner side of the first base portion 110-1. The other end portion of the first elastic portion 120a-1 is a connecting portion 110 on the outer side of the second base portion 110-2 that faces the inner side of the first base portion 110-1 along the X-axis direction. -2a.

  The first elastic portion 120b-1 is a member having elasticity such as a spring made of, for example, silicon, copper alloy, iron alloy, other metal, resin, or the like. The first elastic part 120b-1 is arranged so as to extend in the X-axis direction in FIG. In other words, the first elastic part 120b-1 has a shape having a long side extending in the X-axis direction and a short side extending in the Y-axis direction. However, the first elastic portion 120b-1 has a shape having a short side extending in the X-axis direction and a long side extending in the Y-axis direction according to the setting state of the resonance frequency described later. Or may have any other shape. One end of the first elastic portion 120b-1 is connected to the frame portion 110-2h of the second base portion 110-2 along the X-axis direction. The other end of the first elastic portion 120b-1 is connected to the inner side of the first base portion 110-1 along the X-axis direction.

  The 2nd base part 110-2 has a frame shape provided with a space inside. That is, it has an upper side 110-2ou parallel to the X-axis in FIG. 5, a vertical side 110-2a, a lower side 110-2od parallel to the X-axis direction, and a rectangular frame part 110-2h for mounting the coil. . The three sides are connected to each other, starting from the upper left end of the frame part 110-2h, connected in the order of the upper side 110-2ou, the vertical side 110-2a, and the lower side 110-2od, resulting in the lower left end of the frame part 110-2h. . The first elastic part 120a-1 is connected to the connection part 110-2a of the second base part 110-2, and the first elastic part 120b-1 is connected to the center of the right side of the frame part 110-2h. The

  The second base portion 110-2 has a vertically symmetrical shape with the center line of the first elastic portion 120-1 as the axis of symmetry. However, the 2nd base part 110-2 is not limited to these, For example, it has other shapes (For example, a square, a rhombus, a hexagon, an octagon, a polygon, a circle, an ellipse shape, etc.). It may be. Needless to say, it does not have to be symmetrical.

  The sides constituting the second base part 110-2 (upper side 110-2ou, vertical side 110-2a, lower side 110-2od, frame part 110-2h) may have the same thickness or different thicknesses depending on the side. It may be good or may be reinforced with ribs or the like. In order to suitably realize a stationary wave-like deformation vibration between the second base portion and the first elastic portion, which will be described in detail in the operation section, the side rigidity may be varied. Specifically, it is preferable to make the rigidity of the side along the direction of the Y-axis higher than the rigidity of the side along the direction of the X-axis. The rigidity here is not a mere hardness (Young's modulus), In other words, the resonance frequency of the deformation vibration of the second base portion 110-2 along the Y-axis direction is the resonance frequency of the deformation vibration of the second base portion 110-2 along the X-axis direction. It should be interpreted as meaning higher than the frequency.

  The second base part 110-2 is arranged to be suspended or supported by the first elastic parts 120a-1 and 120b-1 in the space inside the first base part 110-1. The second base portion 110-2 is configured to rotate about the direction along the X axis as a rotation axis by the elasticity of the first elastic portions 120a-1 and 120b-1. In other words, it is configured to rotate around an axis parallel to the X axis.

 The second elastic portion 120a-2 is a member having elasticity such as a spring made of silicon, copper alloy, iron alloy, other metal, resin, or the like. The second elastic portion 120a-2 is disposed so as to extend in the Y-axis direction in FIG. In other words, the second elastic portion 120a-2 has a shape having a long side extending in the Y-axis direction and a short side extending in the X-axis direction. However, the second elastic portion 120a-2 has a shape having a short side extending in the direction of the Y-axis and a length extending in the direction of the X-axis, depending on the setting state of the resonance frequency described later. Also good. One end of the second elastic portion 120a-2 is connected to the inner side of the upper side 110-2ou of the second base portion 110-2. The other end portion of the second elastic portion 120a-2 is connected to one end portion of the mirror 130 facing the inner side of the second base portion 110-2 along the Y-axis direction.

  The second elastic portion 120b-2 is a member having elasticity such as a spring made of silicon, copper alloy, iron-based alloy, other metal, resin, or the like. The second elastic portion 120b-2 is disposed so as to extend in the direction of the Y axis in FIG. In other words, the second elastic portion 120b-2 has a shape having a long side extending in the Y-axis direction and a short side extending in the X-axis direction. However, the second elastic portion 120b-2 has a shape that has a short side that extends in the direction of the Y axis and a length that extends in the direction of the X axis according to the setting state of the resonance frequency described later. Also good. One end of the second elastic portion 120b-2 is connected to the inside of the lower side 110-2od of the second base portion 110-2 along the direction of the Y axis. The other end of the second elastic portion 120b-2 is the mirror 130 (on the side where 120a-2 is not connected) facing the inner side of the second base portion 110-2 along the Y-axis direction. Connected to the end.

  The mirror 130 is arranged to be suspended or supported by the second elastic portions 120a-2 and 120b-2 in the gap inside the second base portion 110-2. The mirror 130 is configured to rotate about the axis along the Y-axis direction as a rotation axis by the elasticity of the second elastic portions 120a-2 and 120b-2. In other words, it is configured to rotate around an axis parallel to the Y axis.

  The drive source unit 140 causes the coil unit 141 to generate a torsional force necessary for rotating the mirror 130 about the axis along the Y-axis direction as a central axis. That is, as will be described later, the first elastic portion 120a-1, the second base portion 110-2 (including the mirror 130, the second elastic portions 120a-2, 120b-2), and the first elastic portion 120b-1. Thus, an exciting force for resonating in a standing wave shape (a stationary wave-like deformation vibration described later) can be applied. Moreover, you may be comprised so that force can be applied with respect to the 2nd base part 110-2. Specifically, by applying a twisting force around the axis along the X axis to the second base portion 110-2, a force for rotating the second base portion 110-2 and the mirror 130 connected thereto may be applied. Good.

  More specifically, the drive source unit 140 is a drive source unit that applies a force due to an electromagnetic force, and forms a coil unit 141 and a magnetic field applying unit fixed to the first base unit 110-1. 142a, 142b, 142c, 142d, and 142e. In this case, a desired current is applied to the coil unit 141 at a desired timing from a drive source unit control circuit (not shown), and electromagnetic interaction occurs between the coil unit 141 and the magnetic poles 142a to 142e. As a result, electromagnetic force due to electromagnetic interaction is generated. This electromagnetic force is transmitted to the coil part 141, the first elastic part 120 (120a-1, 120b-1), the second base part 110-2, and the mirror 130 as a torsional force, and rotates the mirror 130.

  The coil unit 141 includes a winding made of, for example, a material having relatively high conductivity (for example, gold, copper, aluminum, or the like). It may be formed by plating or vapor deposition on the frame part 110-2h of the second base part 110-2, or may be formed by etching or the like. In the second embodiment, the coil portion 141 has a rectangular shape. However, the coil part 141 may have an arbitrary shape (for example, a square, a rhombus, a parallelogram, a circle, an ellipse, a polygon, or any other loop shape).

  The coil part 141 is arranged on the second base part 110-2 so as to be shifted with respect to the mirror 130. That is, the coil part 141 is arrange | positioned in the position shifted in the predetermined direction (other direction, X-axis direction) from the location where the mirror 130 is arrange | positioned. More specifically, the coil unit 141 has a center (for example, the center of the coil unit) at a position shifted in a predetermined direction from a position where the center of the second base unit 110-2 (that is, the rotation center or the center of gravity of the mirror 130) is arranged. It is arranged on the second base part 110-2 so that the center or the center of gravity of the winding is arranged. In other words, the mirror 130 is disposed outside the winding wire that constitutes the coil 141.

  The magnetic field applying unit includes a permanent magnet and a yoke (magnetic material such as iron) that induces a magnetic field, and applies a magnetic field to the coil unit 141 from the magnetic poles 142a to 142e. The magnetic poles 142a to 142e are arranged around the coil portion 141. The magnetic poles 142a and 142b are arranged so as to sandwich the coil part 141 along the Y-axis direction. The description will be made using an example in which the magnetic pole 142a is on the magnetic field exit side (N pole) and the magnetic pole 142b is on the magnetic field entrance side (S pole). Needless to say, the exit side (N pole) and the incident side (S pole) ) May be replaced. Similarly, the magnetic pole 142c and the magnetic poles 142d and 142e are arranged so as to sandwich the coil portion 141 along the X-axis direction. The description will be made using an example in which the magnetic pole 142c is on the magnetic field exit side (N pole) and the magnetic poles 142d and 142e are on the magnetic field entrance side (S pole). Needless to say, the output side (N pole) and the incident side ( It does not matter if the S pole) is replaced. Needless to say, the number of magnetic poles is not limited to the above numerical value, and may be set as appropriate. An electromagnet may be used instead of the permanent magnet.

Next, a configuration including the drive source unit 140 will be described with reference to FIG.
FIG. 6 shows the first elastic part 120a-1, the second base part 110-2 (including the mirror 130, the second elastic parts 120a-2, 120b-2 and the coil part 141), the first elastic part 120b-1, and It is the figure which looked at the magnetic poles 142c-142e from the side.

As shown in FIG. 6, the first elastic portion 120a-1, the second base portion 110-2 (including the mirror 130, the second elastic portions 120a-2, 120b-2, and the coil portion 141), the first elastic portion 120b. −1 are continuous and vibrate in a standing wave shape (resonance). The vibration state at this time is a position corresponding to the center of the mirror 130, that is, a node appears at the connection part of the second base part 110-2 and the second elastic part 110-2, and a node appears at the center position of the coil part 141. Appear, a belly appears near the center of the second base part 110-2, a belly appears at the connection part between the first elastic part 120a-1 and the second base part, and 120b-1 and the second base part A belly appears at the connection. The rigidity, mass, and the like of each part are adjusted so that such a kneaded standing wave-like vibration state appears. Since this resonance will be described in detail as a standing-wave-like deformation vibration with the second base portion and the first elastic portion in the section of operation, only the outline thereof will be described here.
(2-2) Operation of the MEMS mirror driving device

  Subsequently, an operation mode (specifically, an operation mode of rotating the mirror 130) of the MEMS mirror driving device 101 of the second embodiment will be described with reference to FIGS.

  First, with reference to FIG. 5, the rotation about the axis along the X-axis direction of the mirror 130 as a central axis will be described. During the operation of the MEMS mirror driving device 101 of the second embodiment, a desired current is applied to the coil unit 141 at a desired timing from a drive source unit control circuit (not shown), and the coil unit 141 and the magnetic poles 142a and 142b Electromagnetic interaction occurs between the two. As a result, electromagnetic force due to electromagnetic interaction is generated. This electromagnetic force becomes a force that twists the coil part 141 about the axis along the X-axis direction as a center axis, and rotates the second base part 110-2 around the axis along the X-axis direction as a center axis. Therefore, the mirror 130 connected to the second base portion is also rotated about the axis along the X-axis direction as the central axis.

  Here, the direction of the electromagnetic force due to the electromagnetic interaction between the coil portion 141 and the magnetic pole 142a is from the back side (the back side of the paper) to the near side (the front side of the paper) in FIG. The direction of the electromagnetic force by the electromagnetic interaction between the coil part 141 and the magnetic pole 142b is from the front side to the back side in FIG. As a result, the electromagnetic force rotates the coil unit 141 with the extending direction (the direction along the X axis) of the first elastic units 120a-1 and 120b-1 as the rotation axis direction. As a result, the second base portion 110-2 to which the coil portion 141 is attached rotates about the axis along the X-axis direction as a central axis, and the mirror 130 supported by the second base portion 110-2 also includes the above-described mirror 130. It rotates with the axis along the X-axis direction as the central axis.

  Note that the second base portion 110-2 (including the second elastic portions 120a-2 and 120b-2 and the mirror 130) may repeatedly rotate at a frequency lower or higher than a mirror resonance frequency described later. For example, when the MEMS mirror driving device 101 of the second embodiment is applied to a display (or a head mounted display), the second base portion 110-2 (second elastic portions 120a-2 and 120b-2 and the mirror 130). May repeat the rotation operation at a frequency (for example, 60 Hz) corresponding to the scanning period or frame rate of the display, for example.

  Alternatively, the second base portion 110-2 (including the second elastic portions 120a-2 and 120b-2 and the mirror 130) is a suspended portion such as the second base portion 110-2 and the mirror 130, and the first elastic portion 120. The rotation operation at a more specific resonance frequency may be repeated. Specifically, the second base portion 110-2 (including the second elastic portions 120a-2 and 120b-2 and the mirror 130) includes the second base portion 110-2 and the suspended portion such as the coil portion 141 and the second base portion 110-2. You may rotate so that it may resonate with the resonance frequency defined according to 1 elastic part 120a-1 and 120b-1. For example, the moment of inertia around the axis along the X axis of the second base portion 110-2 (including the mirror 130) (more specifically, the second elastic portion 120a provided in the second base portion 110-2). -2 and 120b-2 and the second base portion 110-2 including the respective masses of the mirror 130, the suspension moment portion consisting of the entire system, ie, the inertia moment about the axis along the X axis) is I1; If the torsion spring constant when the first elastic parts 120a-1 and 120b-1 are regarded as one spring is k1, the second base part 110-2 (second elastic parts 120a-2, 120b- 2 and the mirror 130) is a resonance frequency specified by (1 / (2π)) × √ (k1 / I1) or near the resonance frequency (or (1 / (2π)) × √ (k1 / I1) N times (where N is 1 or more) To resonate at an integer) the resonant frequency of), it may be rotated about axis an axis along the direction of the X axis.

  Next, with reference to FIG. 5 and FIG. 6, the rotation about the axis along the Y-axis direction of the mirror 130 as a central axis will be described. During the operation of the MEMS mirror driving device 101 of the second embodiment, a desired control current is applied to the coil unit 141 at a desired timing from a drive source unit control circuit (not shown).

  The control current includes a current component for rotating the mirror 130 about the axis along the Y-axis direction as a rotation axis. In the second embodiment, the mirror 130 has a resonance frequency determined by the mirror 130 and the second elastic portions 120a-2 and 120b-2 with a standing wave shape of the second base portion 110-2 and the first elastic portion 120-1 described later. Using the deformation vibration, the axis along the Y-axis direction is rotated about the axis of rotation so as to resonate at the transitioned frequency. In other words, the resonance rotation is performed at a frequency different from the resonance frequency determined by the mirror 130 and the second elastic portions 120a-2 and 120b-2.

  In this embodiment, when a single coil portion is used, two or more signals may be superimposed in order to drive two or more axes. That is, a signal in which two signals of a current component responsible for rotation around the axis along the X-axis direction and a current component responsible for rotation around the axis along the Y-axis direction are superimposed on the drive coil 141 may be applied.

  Here, as shown in FIG. 5, a control current flowing in a counterclockwise direction is supplied to the coil unit 141, and a magnetic field from the magnetic pole 142 c to the magnetic poles 142 d and 142 e is applied to the coil unit 141. By applying a current to the coil unit 141, electromagnetic interaction occurs between the coil unit 141 and the magnetic pole 142c, the magnetic pole 142d, and the magnetic pole 142e.

  The direction of the electromagnetic force due to the electromagnetic interaction between the coil part 141 and the magnetic pole 142c is from the back side (the back side of the paper) to the near side (the front side of the paper) in FIG. The direction of electromagnetic force due to electromagnetic interaction between the coil portion 141 and the magnetic pole 142d and magnetic pole 142e is from the front side to the back side in FIG.

  In other words, as shown in FIG. 6, the direction of the electromagnetic force due to the electromagnetic interaction between the coil portion 141a and the magnetic pole 142c is from the lower side to the upper side in FIG. The direction of electromagnetic force due to electromagnetic interaction between the coil portion 141b, the magnetic pole 142d, and the magnetic pole 142e is from the upper side to the lower side in FIG. That is, electromagnetic forces in directions different from each other are generated on the two long sides of the coil portion 141 facing in the X-axis direction. In other words, an electromagnetic force serving as a couple is generated on the two long sides 141a and 141b of the coil portion 141 facing in the X-axis direction. Accordingly, the coil portion 141 rotates in the clockwise direction in FIG.

  On the other hand, since the control current is an alternating current, a control current flowing in the clockwise direction is supplied to the coil unit 141 after a half cycle. Accordingly, the coil portion 141 rotates in the clockwise direction in FIG. As a result, the coil unit 141 repeatedly rotates about the axis along the Y-axis direction as a rotation axis.

  The repeated rotation of the coil 141 as described above is transmitted to the second base portion 110-2 and the first elastic portion 120-1 as torsional vibration of the coil portion 141 with the axis along the Y-axis direction as the central axis. A stationary wave-like deformation vibration of the second base portion and the first elastic portion is generated.

  At this time, the rotation axis of the coil unit 141 along the Y-axis direction is different from the rotation axis of the mirror 130 along the Y-axis direction. Specifically, the rotation axis of the coil unit 141 along the Y-axis direction exists at a position shifted by a predetermined distance in the X-axis direction with reference to the rotation axis of the mirror 130 along the Y-axis direction. For this reason, the rotation of the coil unit 141 having the axis along the Y-axis direction as the rotation axis does not directly rotate the mirror 130 about the axis along the Y-axis direction as the rotation axis. In other words, the coil part 141 is a stationary wave-like deformation for rotating the mirror 130 instead of applying a force that imparts a twist in the rotational direction to the mirror 130 (supported by the second base part 110-2) itself. An excitation force (torsional vibration) is applied as a vibration energy source.

  Next, the standing-wave deformation vibrations of the second base part and the first elastic part will be described with reference to FIG. The first elastic part 120a-1, the second base part 110-2 (including the second elastic parts 120a-2 and 120b-2 and the mirror 130), and the first elastic part 120b- are generated by the rotational force generated by the coil part 141. 1 are connected to each other, and are deformed and oscillated in the form of a standing wave along the other direction, resulting in resonance. In other words, the first elastic portion 120a-1, the second base portion 110-2 (including the second elastic portions 120a-2 and 120b-2 and the mirror 130), and the first elastic portion 120b-1 are connected to form an X axis. Vibrates along a direction in a deformed state like the triple mode of a string. That is, a part of the first elastic portion 120a-1, the second base portion 110-2 (including the second elastic portions 120a-2 and 120b-2 and the mirror 130), and the first elastic portion 120b-1 are in a standing wave shape. Deformation vibration in which the deformation vibration becomes an antinode and the other part becomes a node of the deformation wave having a standing wave shape.

  In the above-described stationary wave-like deformation vibration, a node appears at the center of the coil portion 141. A node appears at the connection portion of the second elastic part of the upper side 110-2ou and the lower side 110-2od of the second base part 110-2, in other words, at the position of the rotation center of the mirror 130. A belly appears at the center of the second base part 110-2, and a belly appears at the connection between the right end of the first elastic part 120a-1 and the second base part 110-2a, and the first elastic part 120b-1 A belly appears at the connection between the left end and the second base portion 110-2h. That is, the coil part 141 is in the position of the node in the standing wave.

On the other hand, as described above, the center of rotation of the mirror 130 is at the position of the node. For this reason, as shown in FIG. 6, the movement is small in the vertical direction (the direction along the Z axis), and a rotational movement around the axis along the direction of the Y axis is generated, so that the rotation can be enjoyed suitably. . The above-described deformation vibration shows a so-called standing wave-like deformation state, and the positions of the antinodes and nodes are substantially fixed.
However, the above-described mirror 130 or coil part 141 being in the position of the node does not mean that the mirror 130 or the coil part 141 is strictly located, and it may be interpreted that the mirror 130 or the coil part 141 is in a position close to the node. It is better to grasp that the closer to the knot, the more efficient the rotation.

  Such a standing wave-like deformation of the first elastic part 120a-1, the second base part 110-2 (including the second elastic parts 120a-2 and 120b-2 and the mirror 130) and the first elastic part 120b-1. Due to the vibration, the mirror 130 is rotated.

  The rotational resonance of the mirror 130 and the stationary wave-like deformation vibration of the second base portion and the first elastic portion are generated at the same frequency, but the frequency is different from the resonance frequency determined by the mirror 130 and the second elastic portion. . That is, the resonance frequency of the mirror 130 is changed by a standing wave-like deformation vibration of the second base portion and the first elastic portion. As a result, the mirror 130 resonates at a frequency different from the resonance frequency determined by the mirror 130 and the second elastic portion. The resonance frequency of the mirror 130 at this time is typically higher than the resonance frequency determined by the mirror 130 and the second elastic part. Further, at this time, the rotation angle of the mirror 130 becomes larger than that in the case where the frequency is not shifted by the stationary wave-like deformation vibration.

  In order to realize the above-described standing-wave deformation vibration, the first elastic part 120a-1, the second base part 110-2 (including the second elastic parts 120a-2 and 120b-2 and the mirror 130), and the first The rigidity, mass, length, etc. of the elastic part 120b-1 are adjusted. Specifically, the length, cross-sectional shape, rigidity, shape of the second base part 110-2, mass, rigidity, shape of the coil part 141, mass, rigidity, etc. may be adjusted. By adjusting these, the position of the node, the antinode, and the resonance frequency become appropriate, the above-described stationary wave-like deformation vibration is suitably realized, and the preferred rotation of the mirror 130 is realized.

  Here, a method for adjusting the resonance frequency in the standing wave-like deformation vibration will be described in more detail with reference to FIGS. In recent years, computing technology has developed, and simulations can be performed easily on a personal computer without trial production, and the values of the trial production and simulation match with high accuracy. Here, as an example of simulation by a personal computer, a method for adjusting a resonance frequency and a method for adjusting rigidity in a standing wave-like deformation vibration will be described. The resonance frequency of the target mirror 130 is about 25 kHz.

(Adjustment 1)
First, the resonance frequency of the mirror 130 determined by the mirror 130 and the second elastic part 120-2 is calculated. The mirror 130, the second elastic part (120a-2, 120b-2), the second base part 110-2, and the coil part 141 are equipped, and the thickness, diameter, length, width, etc. are appropriately adjusted. Then, complete fixation is input as the boundary condition of the second base unit 110-2. If eigenvalue analysis (resonance frequency analysis) is performed with simulation software in this state, the resonance frequency of the mirror 130 determined by the mirror 130 and the second elastic portion 120-2 is calculated. At this time, the dimensions of each part are determined (by repetitive calculation) so that the resonance frequency of the mirror 130 in the rotational direction along the Y-axis direction is 25 kH.

(Adjustment 2)
Next, the first elastic portions 120a-1 and 120b-1 and the first base portion 110-1 are additionally equipped, and the thickness, length, width, etc. are appropriately adjusted. In this state, when complete fixing is input as the boundary condition of the first base part-1, the first elastic part 120a-1, the second base part 110-2 (second elastic parts 120a-2, 120b-2, and mirrors). 130), and the resonance frequency and resonance mode of the standing-wave-like resonance (combined rotational motion and translational motion) of the first elastic portion 120b-1. The dimensions (thickness, length, width, size) of each part are adjusted so that the Nth-order resonance mode at this time becomes a deformed state like the triple mode of the string as shown in FIG. Further, it is preferable to finely adjust each part so that a node appears at a position corresponding to the rotation axis of the mirror 130 (rotation center of the mirror) and a position of the rotation center of the coil unit 141.

  If the resonance frequency in the above-described vibration state is calculated to be 25.000 kHz, this state indicates that the frequency of the standing-wave-like deformation vibration is the resonance frequency of the mirror 130 (mirror 130 (driven portion) and the second elastic portion 120). The condition is adjusted to match.

(Adjustment 3)
However, the above-mentioned state (25.000 kHz) is not the best state in this embodiment. Next, for example, a case where the thickness of the upper side 110-2ou and the lower side 110-2od of the second base part 110-2 is slightly increased is assumed. Since the spring rigidity increases in proportion to the cube of the thickness and the mass is proportional to the thickness of the first power (in other words, the rigidity increases but the mass does not increase so much), the resonance of the system including the second base portion 110 The frequency increases, and the resonance frequency of the standing wave-like deformation vibration increases.

Then, it is assumed that the calculation result by the simulation is changed to 25.25 KHz (frequency of the standing wave-like deformation vibration = frequency of the driven part). The concept of the vibration state at this time is shown in FIG. The amplitude of the standing wave-like deformation vibration decreases and the rotation angle of the mirror increases. At this time, the mirror 130 resonates at a frequency different from the frequency (25.000 kHz) determined by the mirror 130 and the second elastic portion 120-2.
(Resonant frequency of mirror is changed by standing wave deformation vibration)

  On the contrary, when the same simulation is performed with the thickness of the upper side 110-2ou and the lower side 110-2od of the second base part 110-2 being reduced, the resonance frequency of the standing wave-like deformation vibration is lowered 24. .75 KH, the amplitude of the standing-wave deformation vibration is increased, and the touch angle of the mirror 130 is decreased.

  Thus, in this embodiment, the mirror 130 resonates at a resonance frequency different from the resonance frequency determined by the mirror 130 and the second elastic portion 120-2. In other words, the resonance frequency of the mirror 130 is shifted by the standing wave-like deformation vibration.

  Also, according to various aspects of the calculation, typically, the mirror rotation angle increases when the resonance frequency of the mirror 130 is shifted to a higher frequency by a standing wave-like deformation vibration.

  When the rotation direction of the coil portion 141 and the rotation direction of the mirror 130 are the same (referred to as in-phase), the above transition frequency (deviation) tends to increase, and the deviation is 1% to 10%. There is an example that becomes a degree. Further, as shown in FIG. 8, when the movements of the second base unit 110-2 and the mirror 130 are in opposite directions (referred to as reverse phase), the above-described deviation is small, and the deviation is from 0.03% to 2%. There is an example which becomes about%.

  Or, as an example, when the vibration mode of the standing wave-shaped deformation vibration is set to a lower mode, that is, a vibration mode close to the double mode of the string, the above transition frequency (deviation) tends to increase. There have been confirmed examples of up to 30%.

  In addition, contrary to the above-described typical example, there is also an example in which it is preferable that the resonance frequency of the mirror 130 is changed to a low level by a standing wave-like deformation vibration. It should be added that the frequency may be set lower than the frequency determined by the unit 120-2.

  Here, regarding the resonance frequency of the mirror 130, the different resonance frequencies (frequency deviations) will be mentioned. A structure composed of silicon such as MEMS and a metal spring has a small attenuation as a material, and the resonance peak in the frequency characteristic diagram has a sharp and steep shape. A typical numerical value representing the sharpness of the resonance peak is a Q value. The MEMS and metal have a large Q value, typically about 1500. Here, the deviation of the resonance frequency will be described using the Q value.

  The definition of the Q value is as follows: ω is the resonance frequency at the resonance peak, ω1 is the frequency at which the vibration energy is half the resonance peak on the frequency side lower than ω, and ω2 is the half value of the resonance peak on the frequency side higher than ω. Q value is represented by Q = ω / (ω2−ω1). If the above ω = 25000 Hz and Q = 1500 are substituted for the deformation, ω2−ω1 = 25000/1500 = 16.67 Hz. Further, due to the symmetry of the resonance peak, the difference between the resonance peak frequency ω and ω1 (ω2) is 16.67 / 2 = 8.34 Hz. That is, in the frequency characteristics of the drive device, when the excitation resonance frequency is 8.34 Hz away from the resonance peak frequency ω, the resonance energy of the system is reduced to half (the rotation angle is √ (0.5)). 8.34 Hz is 0.0334% ≈0.03% of 25 kHz. Accordingly, the resonance energy is halved by the deviation of the resonance frequency (peak frequency) of 0.03%. Therefore, it can be considered that the difference of 0.03% in the resonance frequency is a sufficient difference. The above-described example is a consideration example when the resonance energy is halved, and the present invention is not limited to this calculation, and the different resonance frequencies may be arbitrarily determined.

  As described above, the MEMS mirror driving device 101 according to the second embodiment can rotate the mirror 130 with the axis along the X-axis direction as the rotation axis, and at the same time, the mirror with the axis along the Y-axis direction as the rotation axis. 130 can be resonantly rotated. That is, the MEMS mirror driving device 101 of the second embodiment can perform biaxial driving.

  Here, the force for rotating and resonating the mirror 130 with the axis along the Y-axis direction as the rotation axis is not an aspect of directly rotating the mirror 130, but an exciting force as an energy source of stationary wave-like deformation vibration in the coil portion. Is added, the mirror 130 is driven to resonate.

In particular, the resonance frequency of the mirror 130 is different from the resonance frequency determined by the mirror 130 and the second elastic portion 120-2. The resonance frequency of the driven part is changed (typically a high frequency) by the stationary wave-like deformation vibration of the second base part 110-2 and the first elastic part 120-1, and the resonance is accurately synthesized. As a result, the driven device can be rotated at a larger rotation angle, and a driving device with higher efficiency and lower power consumption can be provided.
(3) Third Embodiment A third embodiment of the MEMS mirror driving device will be described with reference to FIG.
(3-1) Basic configuration

  A basic configuration of the MEMS mirror driving device 102 of the third embodiment will be described. FIG. 9 is a plan view conceptually showing the basic structure of the MEMS mirror driving device 102 of the third embodiment.

  As shown in FIG. 9, the MEMS mirror driving device 102 of the third embodiment includes a first base portion 110-1, a first elastic portion 120 including first elastic portions 120a-1 and 120b-1, and an upper side 110. -2ou, vertical side 110-2a, vertical side 110-2b, lower side 110-2od, second base portion 110-2, and second elastic portions 120a-2 and 120b-2, second elastic portion 120-2. And the mirror 130, the movable side electrodes 151a to 151f that are directly and indirectly connected to the second base part 110-2, and the first base part 110-1 that are directly or indirectly connected to the mirror 130. Drive source section 140 including fixed side electrodes 152a to 152f. Instead of the electromagnetic drive of the first embodiment, the third embodiment is an electrostatic drive system using electrostatic attraction, but the other basic configuration is the same as that of the first embodiment, and the same reference numerals are given. Therefore, the detailed description is abbreviate | omitted.

Further, the shape of the second base portion is not limited to a rectangle as in the first embodiment, and the shape may be appropriately changed. Also, the configuration (shape, number, etc.) of the electrodes constituting the drive source section (fixed section side electrode, movable section side electrode) may be changed as appropriate.
(3-2) Operation of MEMS mirror driving device

  An operation mode (specifically, an operation mode of rotating the mirror 130) of the MEMS mirror driving device 102 of the third embodiment will be described. During operation of the MEMS mirror driving device 103 of the third embodiment, a desired voltage is applied to the drive source unit 140 at a desired timing from a drive source unit control circuit (not shown), and the movable side electrodes 151a to 151f are An electrostatic attractive force is generated between the fixed side electrodes 152a to 152f. This electrostatic attraction force causes the mirror 130 to rotate with the second base portion 110-2 (including the mirror 130) twisted about the axis along the X-axis direction as the center axis and the axis along the Y-axis direction as the rotation axis. Generates slight vibration.

  In the third embodiment, since the electromagnetic force in the first embodiment is replaced by electrostatic attraction, the application timing of the driving force is slightly different, but basically the same operation is performed. Therefore, an effect equivalent to that of the first embodiment can be enjoyed.

  The MEMS mirror driving device 102 according to the third embodiment can rotate the mirror 130 with the axis along the X-axis direction as a rotation axis, and at the same time, the mirror 130 can resonate with the axis along the Y-axis direction as the rotation axis. I can do it. That is, the MEMS mirror driving apparatus 100 of the third embodiment can perform biaxial driving.

  Here, the force for rotationally resonating the mirror 130 about the axis along the Y-axis direction is not an aspect of directly rotating the mirror 130, but an excitation force as an energy source of deformation vibration is applied to the electrostatic electrode portion. In addition, the mirror 130 is resonantly driven.

In particular, the resonance frequency of the mirror 130 is different from the resonance frequency determined by the mirror 130 and the second elastic portion 120-2. The resonance frequency of the mirror 130 is shifted (typically a high frequency) by the stationary wave-like deformation vibration of the second base portion 110-2 and the first elastic portion 120-1, and the resonance is accurately synthesized. Thus, the driven device can be rotated at a larger rotation angle to provide a driving device with higher efficiency and lower power consumption.
(3) Fourth Embodiment A fourth embodiment of the MEMS mirror driving device will be described with reference to FIGS.
(4-1) Basic configuration

  A basic configuration of the MEMS mirror driving device 103 according to the fourth embodiment will be described. FIG. 10 is a plan view conceptually showing the basic structure of the MEMS mirror driving device 103 of the fourth embodiment.

  As shown in FIG. 10, the MEMS mirror driving device 103 of the fourth embodiment includes a first base portion 110-1, a first elastic portion 120 including first elastic portions 120a-1 and 120b-1, and an upper side 110. -2ou, vertical side 110-2a, vertical side 110-2b, lower side 110-2od, second base portion 110-2, and second elastic portions 120a-2 and 120b-2, second elastic portion 120-2. And the mirror 130, the coil part 141 disposed on the second base part 110-2, the drive source part 140 including the magnetic poles 142a and 142b as the magnetic field applying part, and the second base part 110-2 directly. And a piezoelectric drive source section 143 including piezoelectric bodies 143a to 143d that are installed either manually or indirectly.

  The fourth embodiment is the same as the first embodiment in the aspect in which the direction along the X axis is the rotation axis, but is the electromagnetic drive of the first embodiment in the aspect in which the direction along the Y axis is the rotation axis. Instead, a piezoelectric drive system using a piezoelectric body is employed.

  The piezoelectric drive source unit 143 causes the second base unit 110-2 to generate vibrations necessary for rotating the mirror 130 about the axis along the Y-axis direction as a central axis. That is, as in the first embodiment, the first elastic part 120a-1, the second base part 110-2 (including the mirror 130, the second elastic parts 120a-2, 120b-2), the first elastic part 120b- Excitation force for resonating in a standing wave shape (a standing wave-like deformation vibration described later) can be applied.

  More specifically, the piezoelectric bodies 143a to 143d are directly or indirectly installed on the second base portion, and the piezoelectric body itself generates a displacement that expands or contracts. Therefore, the second base portion 110-2 is configured to generate deformation vibrations according to the bimetal principle. The other basic configuration is the same as that of the first embodiment, and the detailed description thereof is omitted by attaching the same reference numerals.

Further, the shape of the second base portion is not limited to a rectangle as in the first embodiment, and the shape may be appropriately changed. The configuration (shape, number, etc.) of the piezoelectric bodies 143a to 143d constituting the piezoelectric drive source unit 143 may be changed as appropriate.
(4-2) Operation of MEMS mirror driving device

  An operation mode (specifically, an operation mode for rotating the mirror 130) of the MEMS mirror driving device 103 of the fourth embodiment will be described. FIG. 10 is a plan view conceptually showing the basic structure of the MEMS mirror driving device 103 of the fourth embodiment. FIG. 11 is a side view conceptually showing an operation mode of the MEMS mirror driving device 103 of the fourth embodiment. The aspect that rotates about the axis along the X-axis direction as the central axis is the same as in the first embodiment, and is omitted, and the aspect that rotates about the axis along the Y-axis direction as the central axis will be described.

  When the mirror 130 rotates with the axis along the Y-axis direction as the central axis, a desired voltage is applied to the piezoelectric drive source unit 143 from a drive source unit control circuit (not shown) at a desired timing. In the bodies 143a to 143d, expansion and compression forces as shown in FIG. 10 are generated. A force in the extending direction is generated in the piezoelectric bodies 143a and 143b, and a force in the contracting direction is generated in the piezoelectric bodies 143c and 143d.

  As a result, a deformation force is generated in the second base portion due to the bimetal principle, and the second base portion is deformed as shown in FIG. 11, and this deformation is the same as in the first embodiment. The second base portion 110-2 (including the second elastic portions 120a-2 and 120b-2 and the mirror 130) and the first elastic portion 120b-1 are caused to generate deformation waves having a standing wave shape, and the mirror 130 is rotated by resonance. It is done.

  The rotational resonance of the mirror 130 and the stationary wave-like deformation vibration of the second base portion and the first elastic portion are generated at the same frequency, but the frequency is different from the resonance frequency determined by the mirror 130 and the second elastic portion. . That is, the resonance frequency of the mirror 130 is changed by a standing wave-like deformation vibration of the second base portion and the first elastic portion. As a result, the mirror 130 resonates at a frequency different from the resonance frequency determined by the mirror 130 and the second elastic portion. The resonance frequency of the mirror 130 at this time is typically higher than the resonance frequency determined by the mirror 130 and the second elastic part. Further, at this time, the rotation angle of the mirror 130 becomes larger than that in the case where the frequency is not shifted by the stationary wave-like deformation vibration. Other operations are the same as those in the first embodiment. Therefore, an effect equivalent to that of the first embodiment can be enjoyed.

  The MEMS mirror driving device 103 according to the fourth embodiment can rotate the mirror 130 with the axis along the X-axis direction as the rotation axis, and at the same time, the mirror 130 can resonate with the axis along the Y-axis direction as the rotation axis. I can do it. That is, the MEMS mirror driving device 100 of the fourth embodiment can perform biaxial driving.

  Here, the force for rotating and resonating the mirror 130 about the axis along the Y-axis direction is not an aspect of directly rotating the mirror 130, but an excitation force is applied to the piezoelectric drive source as an energy source of deformation vibration. As a result, the mirror 130 is driven to resonate.

In particular, the resonance frequency of the mirror 130 is different from the resonance frequency determined by the mirror 130 and the second elastic portion 120-2. The resonance frequency of the mirror 130 is shifted (typically a high frequency) by the stationary wave-like deformation vibration of the second base portion 110-2 and the first elastic portion 120-1, and the resonance is accurately synthesized. Thus, the driven device can be rotated at a larger rotation angle to provide a driving device with higher efficiency and lower power consumption.
(5) Fifth Embodiment A fifth embodiment of the MEMS mirror driving device will be described with reference to FIGS.
(5-1) Basic configuration

  A basic configuration of the MEMS mirror driving device 104 of the fifth embodiment will be described. FIG. 12 is a plan view conceptually showing the basic structure of the MEMS mirror driving device 104 of the fifth embodiment.

  As shown in FIG. 12, the MEMS mirror driving device 104 of the fifth embodiment is similar to the first embodiment in that the first base portion 110-1 and the first elastic portions 120a-1 and 120b-1 are the first. The elastic portion 120 includes a second base portion 110-2 including an upper side 110-2ou, a vertical side 110-2a, a vertical side 110-2b, and a lower side 110-2od, and second elastic portions 120a-2 and 120b-2. A second elastic part 120-2, a mirror 130, a coil part 141, and a drive source part 140 including magnetic poles 142a to hh as magnetic field applying parts are provided. What differs from the first embodiment is the rigidity of the second base portion 110-2.

The rigidity of each side constituting the second base portion 110-2, that is, the upper side 110-2ou, the vertical side 110-2a, the vertical side 110-2b, and the lower side 110-2od is higher than that in the first embodiment. The shape is difficult to cause deformation. The other basic configuration is the same as that of the first embodiment, and the detailed description thereof is omitted by attaching the same reference numerals.
(5-2) Operation of MEMS mirror driving device

  An operation mode (specifically, an operation mode of rotating the mirror 130) of the MEMS mirror driving device 104 of the fifth embodiment will be described. FIG. 13 is a side view conceptually showing the basic operation of the MEMS mirror driving device 104 of the fifth embodiment. During the operation of the MEMS mirror drive device 104 of the fifth embodiment, a desired current is applied to the drive source unit 140 at a desired timing from a drive source unit control circuit (not shown), and the coil 141 and the magnetic poles 142a to 142h Electromagnetic force is generated between them. This electromagnetic force is a force for twisting the second base portion 110-2 (including the mirror 130) about the axis along the X-axis direction as a central axis and for rotating the mirror 130 about the axis along the Y-axis direction as the rotation axis. A slight vibration is generated.

The rotation about the axis along the X-axis direction as the central axis is the same as that of the first embodiment, and is omitted, and the case where the rotation is performed about the axis along the Y-axis direction as the rotation axis will be described.
In the fifth embodiment, since the rigidity of the second base portion is increased, the deformation of the second base portion 110-2 is small. Therefore, as shown in FIG. 13, the first elastic part 120a-1, the second base part 110-2 (including the mirror 130, the second elastic parts 120a-2, 120b-2, and the coil part 141), the first elastic part 120b. -1 are connected, and the first elastic portions 120a-1 and 120b-1 are the main deformed portions when they vibrate (resonate) in a standing wave shape.

  As in the first embodiment, a desired control current is applied to the coil 141 at a desired timing from a drive source unit control circuit (not shown). The coil unit 141 repeatedly rotates with the axis along the Y-axis direction as a rotation axis, and generates vibration. The vibration generated by the coil 141 becomes an excitation force, and the first elastic part 120a-1, the second base part 110-2 (including the second elastic parts 120a-2 and 120b-2 and the mirror 130), and the first elastic part. 120b-1 continues to generate a standing wave-like vibration. As a result, the mirror 130 is resonated and rotated due to the standing wave vibration.

  The rotational resonance of the mirror 130 and the standing-wave vibration of the second base portion and the first elastic portion are generated at the same frequency, but the frequency is different from the resonance frequency determined by the mirror 130 and the second elastic portion. That is, the resonance frequency of the mirror 130 is changed by standing-wave vibration with the second base portion and the first elastic portion. As a result, the mirror 130 resonates at a frequency different from the resonance frequency determined by the mirror 130 and the second elastic portion. The resonance frequency of the mirror 130 at this time is typically higher than the resonance frequency determined by the mirror 130 and the second elastic part. Further, at this time, the rotation angle of the mirror 130 becomes larger than that in the case where the frequency is not shifted by the stationary wave-like deformation vibration. Other operations are the same as those in the first embodiment. Therefore, an effect equivalent to that of the first embodiment can be enjoyed.

  The MEMS mirror driving device 104 according to the fifth embodiment can rotate the mirror 130 with the axis along the X-axis direction as the rotation axis, and at the same time, the mirror 130 can resonate with the axis along the Y-axis direction as the rotation axis. I can do it. That is, the MEMS mirror driving device 104 of the fifth embodiment can perform biaxial driving.

  Here, the force for rotationally resonating the mirror 130 about the axis along the Y-axis direction is not an aspect of directly rotating the mirror 130, but an excitation force is applied to the coil unit 141 as an energy source of deformation vibration. As a result, the mirror 130 is resonantly driven.

  In particular, the resonance frequency of the mirror 130 is different from the resonance frequency determined by the mirror 130 and the second elastic portion 120-2. By changing the resonance frequency of the mirror 130 (typically a high frequency) by standing-wave-like vibrations of the second base portion 110-2 and the first elastic portion 120-1, and appropriately synthesizing the resonance. The driven device can be rotated at a larger rotation angle to provide a driving device with higher efficiency and lower power consumption.

  Further, in the fifth embodiment, an example of driving by electromagnetic force has been shown, but the present invention is not limited to this, and electrostatic attraction as shown in the third and fourth embodiments, and extension / extension by a piezoelectric body. Contractile force may be used.

The MEMS mirror driving device (100) of the first embodiment described above to the MEMS mirror driving device (104) of the fifth embodiment includes, for example, a head-up display, a head-mounted display, a retinal scanning display, and a laser scanner. It can also be applied to various electronic devices such as laser printers and scanning drive devices. Therefore, these electronic devices are also included in the scope of the present invention.
Further, the present invention can be appropriately changed without departing from the gist or concept of the present invention that can be read from the claims and the entire specification, and a drive device that includes such a change is also included in the technical concept of the present invention. It is.

100, 101, 102, 103, 104, MEMS mirror driving device 110-1 first base unit 110-2 second base unit 110-2a second base unit vertical side 110-2ou second base unit upper side 110-2od second Base part lower side 110-2h 2nd base part coil frame part 120 1st elastic part 120-2 2nd elastic part 120a-1, 120b-1 1st elastic part 120a-2, 120b-2 2nd elastic part 130 Mirror 140 Drive source part 141 Coil part 141a, 141b Coil part 142a, 142b, 142c, 142d, 142e Magnetic pole 143 Piezoelectric drive source part 143a, 143b, 143c, 143d Piezoelectric body 151a, 151b, electrostatic electrode (movable side)
152a, 152b, electrostatic electrode (fixed side)

Claims (18)

  A shaft that connects the first base portion, the second base portion supported by the first base portion, the first base portion and the second base portion, and the second base portion along another direction. A first elastic part having elasticity so as to rotate about a rotation axis, a drive source part installed on the second base part for generating a driving force, a rotatable driven part, and the second base part A second elastic portion that is connected to the driven portion and has elasticity such that the driven portion rotates about an axis along one direction different from the other direction as a rotation axis; The second base portion deforms and vibrates along the other direction due to vibration generated by the source portion, and the driven portion moves along the one direction due to deformation vibration of the second base portion. And the second base portion has a resonance frequency of the driven portion. Deformation caused to transition by the vibration, the drive apparatus which is a frequency different from the resonance frequency determined from the driven portion and the second elastic portion. 2. The driving device according to claim 1, wherein the second base portion and the first elastic portion deform and vibrate in a standing wave shape due to vibration generated by the driving source portion. 3. The driving apparatus according to claim 1, wherein a co-frequency of the driven part is higher than a resonance frequency determined by the driven part and the second elastic part. 4. The drive according to claim 1, wherein a node of deformation vibration appears at a position corresponding to a rotation axis of the driven portion in the standing wave-like deformation vibration of the second base portion and the first elastic portion. apparatus. The electromagnetic driving device according to claim 1, further comprising a magnetic field applying unit, wherein the driving source unit is a coil unit. The electrostatic drive device according to claim 1, further comprising a fixed-side electrode, wherein the drive source unit is an electrostatic electrode. The piezoelectric drive device according to claim 1, wherein the drive source unit is a piezoelectric body.   A shaft that connects the first base portion, the second base portion supported by the first base portion, the first base portion and the second base portion, and the second base portion along another direction. A first elastic portion having elasticity such that the rotating portion is rotated about the rotating shaft, a coil portion disposed on the second base portion, a magnetic field applying portion for applying a magnetic field to the coil portion, and a rotatable cover. It has elasticity that connects the drive unit, the second base unit, and the driven unit, and rotates the driven unit about an axis along one direction different from the other direction as a rotation axis. A second elastic portion, and the coil portion rotates about an axis along one direction and a shaft different from the driven portion as a rotation axis, and the second portion is caused by the rotation of the coil portion. The base portion deforms and vibrates along the other direction, and the second base portion changes. Due to vibration, the driven part rotates about an axis along the one direction as a rotation axis, and the resonance frequency of the driven part is changed by the deformation vibration of the second base part, and the driven part And a driving device having a frequency different from a resonance frequency determined by the second elastic portion. 9. The driving apparatus according to claim 8, wherein the second base part and the first elastic part are deformed and oscillated in a standing wave shape due to the rotation of the coil part. The drive device according to claim 8 or 9, wherein a co-frequency of the driven part is higher than a resonance frequency determined by the driven part and the second elastic part. 11. The drive according to claim 8, wherein a node of deformation vibration appears at a position corresponding to a rotation axis of the driven part in the standing wave-like deformation vibration of the second base part and the first elastic part. apparatus.   A shaft that connects the first base portion, the second base portion supported by the first base portion, the first base portion and the second base portion, and the second base portion along another direction. A first elastic part having elasticity so as to rotate about a rotation axis, a drive source part installed on the second base part for generating a driving force, a rotatable driven part, and the second base part A second elastic portion that is connected to the driven portion and has elasticity such that the driven portion rotates about an axis along one direction different from the other direction as a rotation axis; Due to the vibration generated by the source part, the second base part and the first elastic part vibrate in a standing wave shape along the other direction, and the second base part and the first elastic part vibrate in a standing wave shape. The driven part rotates about the axis along the one direction as a rotation axis. The resonance frequency of the driven part is changed by a standing wave vibration with the second base part and the first elastic part, and is different from the resonance frequency determined by the driven part and the second elastic part. A drive device characterized by the above. The driving apparatus according to claim 12, wherein a co-frequency of the driven part is higher than a resonance frequency determined by the driven part and the second elastic part. The driving apparatus according to claim 12, wherein the frequency of the driven part is 0.03% to 30% higher than a resonance frequency determined by the driven part and the second elastic part. 15. The drive according to claim 12, wherein a node of deformation vibration appears at a position corresponding to a rotation axis of the driven part in the standing wave-like deformation vibration of the second base part and the first elastic part. apparatus. The electromagnetic drive device according to claim 12, further comprising a magnetic field applying unit, wherein the drive source unit is a coil unit. The electrostatic drive device according to claim 12, further comprising a fixed-side electrode, wherein the drive source unit is an electrostatic electrode. 16. The piezoelectric drive device according to claim 12, wherein the drive source unit is a piezoelectric body.