WO2012172654A1

WO2012172654A1 - Drive device

Info

Publication number: WO2012172654A1
Application number: PCT/JP2011/063683
Authority: WO
Inventors: 純鈴木
Original assignee: パイオニア株式会社
Priority date: 2011-06-15
Filing date: 2011-06-15
Publication date: 2012-12-20

Abstract

A drive device (100) comprises: a base section (110); a plurality of driven sections (130a, 130c); a plurality of elastic sections (120a-120d); and an application unit (160) that applies to the base section an excitation force for rotating the plurality of driven sections such that each driven section rotates while resonating, around a central axis being an axis along one direction, at a resonant frequency determined by each of the plurality of driven sections and one elastic section among the plurality of elastic sections that corresponds to each driven section. The application unit applies the excitation force such that the rotation phase of a first driven section among the plurality of driven sections is the reverse phase to the rotation phase of a second driven section among the plurality of drive sections.

Description

Drive device

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

For example, in various technical fields such as a display, a printing apparatus, precision measurement, precision processing, and information recording / reproduction, research on MEMS (Micro Electro Mechanical System) devices manufactured by semiconductor process technology is being actively promoted. As such a MEMS device, for example, a display field in which light incident from a light source is scanned with respect to a predetermined screen region to embody an image, or light reflected by scanning light with respect to a predetermined screen region. In the scanning field where light is received and image information is read, a micro-structured mirror driving device (optical scanner or MEMS scanner) has attracted attention.

In general, a mirror driving device includes a fixed main body serving as a base, a mirror rotatable around a predetermined central axis, and a torsion bar (twisting member) that connects or joins the main body and the mirror. The structure provided is known (refer patent document 1).

Special table 2007-522529

The mirror driving device having such a configuration has a technical problem that the frequency at which the mirror rotates cannot be increased. In other words, the mirror driving device having such a configuration has a technical problem that the cycle of rotating the mirror cannot be shortened.

In contrast to such a conventional mirror driving device, the present invention provides, for example, a driving device (that is, a MEMS scanner) capable of relatively increasing the frequency at which a mirror (or rotating driven object) rotates. It is an issue to provide.

In order to solve the above-described problem, a base unit, a plurality of driven units each rotatable, and a base unit and a corresponding one driven unit among the plurality of driven units are connected. And a plurality of elastic portions each having elasticity that rotates the corresponding one driven portion about an axis along one direction as a central axis, and each of the plurality of driven portions and the plurality of elasticity. The plurality of driven parts rotate at a resonance frequency determined by one elastic part corresponding to each of the driven parts, while resonating with the axis along the one direction as a central axis. An application unit that applies an excitation force for rotating the driven unit to the base unit, and the application unit has a plurality of phases in which a first driven unit of the plurality of driven units rotates. Phase in which the second driven part of the driving part rotates As the reverse phase against, adding the excitation force.

It is a top view which shows notionally the structure of the MEMS scanner of 1st Example. It is a top perspective view which shows the structure of the back side (specifically, the other side of the base shown in FIG. 1) of a base. It is a top view which shows notionally the mode of operation | movement by the MEMS scanner of 1st Example. It is a top view for demonstrating the force without directionality resulting from the fine vibration applied from a drive source part. It is a side view which shows the aspect of a deformation | transformation vibration of a base in relation to the aspect of rotation of a mirror. It is a side view which shows the aspect of a deformation | transformation vibration of a base in relation to the aspect of rotation of a mirror. It is a top view which shows notionally the structure of the MEMS scanner of 2nd Example. It is a top view which shows notionally the structure of the MEMS scanner of 3rd Example. It is a top view which shows notionally the structure of the MEMS scanner of 4th Example. It is a top perspective view which shows the structure of the back side (specifically, the other side of 2nd base shown in FIG. 9) of the 2nd base. It is a top view which shows notionally the aspect of the operation | movement by the MEMS scanner of 4th Example. It is a top view for demonstrating the force without directionality resulting from the fine vibration applied from a drive source part. It is sectional drawing which shows the aspect of the deformation vibration of a 2nd base in relation to the aspect of rotation of a mirror. It is sectional drawing which shows the aspect of the deformation vibration of a 2nd base in relation to the aspect of rotation of a mirror. It is a top view which shows notionally the structure of the MEMS scanner of 5th Example. It is a top view which shows notionally the structure of the MEMS scanner of 6th Example.

Hereinafter, embodiments of the drive device will be described in order.

The driving apparatus according to the present embodiment connects a base unit, a plurality of driven units that can rotate, and a base unit and a corresponding one driven unit among the plurality of driven units. And a plurality of elastic portions each having elasticity that rotates the corresponding one driven portion about an axis along one direction as a central axis, and each of the plurality of driven portions and the plurality of elasticity. The plurality of driven parts rotate at a resonance frequency determined by one elastic part corresponding to each of the driven parts, while resonating with the axis along the one direction as a central axis. An application unit that applies an excitation force for rotating the driven unit to the base unit, and the application unit has a plurality of phases in which a first driven unit of the plurality of driven units rotates. The second driven part of the drive part of the As the reverse phase by, adding the excitation force.

According to the drive device of the present embodiment, an elastic portion (for example, a torsion bar or the like described later) in which the base portion serving as a base and a driven portion (for example, a mirror or the like described later) that is rotatably arranged have elasticity. Connected directly or indirectly by. The driven part is driven to rotate about the axis along one direction as the central axis by the elasticity of the elastic part (for example, the elasticity that the driven part can be rotated about the axis along one direction as the central axis) Is done.

The driving device of the present embodiment includes a plurality of driven parts. The drive device of this embodiment includes a plurality of elastic portions so as to correspond to the plurality of driven portions. For example, the drive device of the present embodiment includes N (where N is an integer of 2 or more) driven parts and N elastic parts. In this case, of the N (where N is an integer of 2 or more) driven parts, the kth (where k is an integer of 1 or more and N or less) driven parts are N elastic parts. Are connected to the base portion by the kth elastic portion corresponding to the kth driven portion.

In the driving apparatus of this embodiment, in particular, each driven unit is in one direction at a resonance frequency determined by each of the plurality of driven units and the corresponding one of the plurality of elastic units by the operation of the application unit. An excitation force that rotates while resonating with the axis along the axis as the central axis is applied. More specifically, the application unit is configured to (i) around the axis along one direction of the first driven unit among the N driven units (that is, the rotation of the first driven unit). The first driven part is centered on the axis along one direction at a resonance frequency determined by the moment of inertia around the axis) and the torsion spring constant of the first elastic part corresponding to the first driven part. (Ii) Inertia around the axis along one direction of the second driven part of the N driven parts (that is, around the rotational axis of the second driven part) The second driven part rotates about the axis along one direction at the resonance frequency determined by the moment and the torsion spring constant of the second elastic part corresponding to the second driven part; ... (N) around the axis along one direction of the Nth driven part among the N driven parts (that is, the Nth driven part) The Nth driven part is equal to the resonance frequency determined by the moment of inertia around the rotation axis of the Nth driven part and the torsion spring constant of the Nth elastic part corresponding to the Nth driven part. An exciting force is applied that rotates about the axis along the direction as the central axis.

Further, in the driving device of the present embodiment, the application unit is configured such that the phase of the first driven unit among the plurality of driven units rotates and the phase of the second driven unit among the plurality of driven units rotates. An excitation force is applied so as to be in reverse phase with respect to. Specifically, for example, the application unit is between a phase in which the first driven unit among the plurality of driven units rotates and a phase in which the second driven unit among the plurality of driven units rotates. Excitation force is applied so that the deviation is 180 °. As a result, when the first driven part is rotating clockwise with respect to the central axis along one direction, the second driven part is relative to the central axis along one direction. Will rotate counterclockwise. Similarly, when the first driven part is rotating counterclockwise with respect to the central axis along one direction, the second driven part is placed on the central axis along one direction. In contrast, it will rotate clockwise. In addition, when the first driven part is rotated by a predetermined amount (or a predetermined angle) clockwise from the reference position, the second driven part is the same position counterclockwise from the reference position. It rotates by a fixed amount (or a predetermined angle). Similarly, in addition, when the first driven part is rotated by a predetermined amount (or a predetermined angle) counterclockwise from the reference position, the second driven part is rotated clockwise from the reference position. It is rotated by the same predetermined amount (or a predetermined angle). Therefore, a plurality of driven parts (for example, first and second driven parts rotating in opposite phases to each other) are compared with a driving apparatus that rotates one driven object at a specific frequency f. By handling like a drive unit, it is possible to realize a state that is substantially the same as a state where one driven unit is rotated at twice the frequency 2f (in other words, with a period of 1/2). it can. In other words, even if each of the plurality of driven parts (for example, the first and second driven parts rotating in opposite phases to each other) is rotated at half the frequency f / 2, the plurality of driven parts (for example, The first and second driven parts that rotate in opposite phases to each other are handled like one driven part, so that one driven part is substantially rotated at twice the frequency f. A similar state can be realized.

In one aspect of the driving device of the present embodiment, the resonance frequency determined by each of the plurality of driven parts and one elastic part corresponding to each of the plurality of elastic parts is the plurality of the plurality of driven parts. It is the same between at least two of the driven parts.

According to this aspect, the resonance frequency determined by one elastic part corresponding to each driven part among each of the plurality of driven parts and the plurality of elastic parts is between at least two of the plurality of driven parts. It will be the same. More specifically, (i) around the axis along one direction of the first driven part among the N driven parts (that is, around the rotation axis of the first driven part). The resonance frequency determined by the moment of inertia and the torsion spring constant of the first elastic part corresponding to the first driven part, and (ii) the second driven part of the N driven parts. It is determined by the moment of inertia around the axis along one direction (that is, around the rotation axis of the second driven part) and the torsion spring constant of the second elastic part corresponding to the second driven part. Resonance frequency, ..., (N) Around the axis along one direction of the Nth driven part among the N driven parts (that is, around the rotation axis of the Nth driven part) ) And the torsion spring constant of the Nth elastic part corresponding to the Nth driven part. At least two of the oscillation frequencies are the same. Therefore, the excitation force is applied from the application unit at a specific period corresponding to the resonance frequency that is the same in at least two of the plurality of driven units, so that at least one of the plurality of driven units is The two can be rotated while resonating and synchronizing.

In another aspect of the driving apparatus of the present embodiment, the application unit applies the excitation force so that the base unit deforms and vibrates in a standing wave shape along another direction different from the one direction. Each of the plurality of driven parts is connected to a location corresponding to a node in the deformation vibration of the base part via the plurality of elastic parts.

According to this aspect, the base portion to which the excitation force is applied deforms and vibrates in a standing wave shape (that is, in a standing wave shape) along the other direction. That is, the appearance of the base portion is deformed so that a part thereof becomes an antinode of deformation vibration and the other part becomes a node of deformation vibration. Due to the deformation vibration of the base portion, the belly and the node appear along other directions. Since the deformation vibration of the base portion is performed in accordance with a so-called standing wave waveform, the positions of its antinodes and nodes are substantially fixed.

Furthermore, according to this aspect, each of the plurality of driven parts is connected to a location corresponding to a node in the deformation vibration of the base part. For this reason, while preventing the movement of the plurality of driven parts in the vertical direction (specifically, the direction perpendicular to the one direction and the other direction and perpendicular to the surface of the base part). The plurality of driven parts can be rotated in opposite phases.

In an aspect of the driving device in which the application unit applies an excitation force so that the base unit deforms and vibrates in a standing wave shape along the other direction, the application unit is configured to perform deformation vibration of the base unit along the other direction. You may comprise so that the said excitation force may be applied so that it may become resonance.

With this configuration, since the deformation vibration of the base portion becomes resonance, the deformation vibration of the base portion can be suitably realized.

In an aspect of the driving device in which the deformation vibration of the base portion resonates, a resonance frequency at which the base portion resonates may be configured to be the same as at least one resonance frequency of the plurality of driven portions. .

If configured in this way, it becomes easy to synchronize between the period of deformation vibration of the base part and the period of rotation of the plurality of driven parts. Accordingly, by appropriately synchronizing the period of deformation vibration of the base portion and the rotation of the plurality of driven parts, the plurality of driven parts can be rotated in opposite phases.

In an aspect of the driving device in which the application unit applies an excitation force so that the base unit deforms and vibrates in a standing wave shape along another direction, the rigidity of the portion corresponding to the node in the deformation vibration of the base unit is determined by the base unit. You may comprise so that it may be higher than the rigidity of places other than the node in deformation vibration of this.

With this configuration, the base portion can be easily deformed and oscillated in a standing wave shape along other directions by adjusting the rigidity of the base portion.

In an aspect of the driving device in which the application unit applies an excitation force so that the base unit deforms and vibrates in a standing wave shape along the other direction, the mass of the portion corresponding to the node in the deformation vibration of the base unit is the base unit. You may comprise so that it may be smaller than the mass of parts other than the node in deformation vibration of this.

With this configuration, by adjusting the mass of the base portion (specifically, for example, the mass per unit length, the mass per unit volume, etc.), the base portion is in a standing wave shape along other directions. Can be easily deformed and vibrated.

In another aspect of the driving apparatus of the present embodiment, the excitation force is non-directional fine vibration or anisotropic fine vibration as non-directional vibration energy.

According to this aspect, the application unit applies a slight vibration to the base portion so that the fine vibration propagates in the structure called the base portion. That is, instead of applying a force that directly twists the base part itself, the application unit applies the excitation energy (in other words, wave energy) for rotating the plurality of driven parts with the fine vibration propagating in the structure. Add as. In other words, the application unit rotates a plurality of driven units with micro vibrations that propagate as energy in the structure (in other words, energy that expresses the force without changing the force of “vibration” into vibration). Add as wave energy for. Such fine vibration (in other words, wave energy propagating in the structure) becomes a force having no directionality at least in the stage of propagation in the structure. In other words, the wave energy propagating in the base portion as a minute vibration propagates in the base portion in an arbitrary direction. As a result, this micro vibration is transmitted as wave energy from, for example, a structure such as a base portion to a plurality of elastic portions (further, from the base portion to a plurality of driven portions via the plurality of elastic portions). After that, micro vibrations (in other words, wave energy) that have propagated through the structure cause the plurality of elastic parts to vibrate in the direction corresponding to the elasticity of the plurality of elastic parts themselves, or according to the elasticity of the plurality of elastic parts. A plurality of driven parts are rotated in the direction of the movement. In other words, this wave energy can be taken out as vibrations in all directions without limiting the direction of micro vibrations. That is, the wave energy propagated in the base portion can be taken out in the form of vibration (more specifically, resonance), and as a result, a plurality of driven portions can be rotated. The wave energy can be extracted to the outside as sound, but the sound generated in this case has a different sound generation principle compared to the sound obtained by so-called piston motion.

Here, when a plurality of driven parts are rotationally driven by applying a so-called directional force (for example, the base part itself is largely twisted in the rotational direction of the plurality of driven parts, Direction of rotating a plurality of driven parts around an axis along one direction as a central axis when the plurality of driven parts are rotationally driven by being directly applied to the elastic part or the plurality of driven parts. (I.e., a force having a directionality that twists a structure such as a base portion in a rotation direction having an axis along one direction as a central axis) from the application unit. For this reason, the arrangement position of the application unit must be appropriately set so that a force having such directionality can be applied. That is, when a force having directionality is applied, the arrangement position of the application unit is limited depending on the direction in which the force is applied.

However, in this embodiment, since a non-directional force due to micro vibration is applied, the arrangement position of the application unit is not limited. In other words, since a non-directional force due to micro vibration is applied, the arrangement position of the application unit is not limited depending on the direction of rotation of the plurality of driven units. In other words, no matter what the arrangement position of the application unit is set, the slight vibration (that is, non-directional force) applied from the application unit is obtained by using the elasticity of the plurality of elastic units. The driven part can be rotated about an axis along one direction as a central axis. Thereby, the freedom degree of design of a drive device can be increased relatively.

According to this aspect, the wave energy propagating in the base portion as non-directional fine vibration or anisotropic fine vibration can be propagated in the base portion in an arbitrary direction. The “non-directional fine vibration” or “anisotropic fine vibration” may be, for example, a fine vibration in a direction uncorrelated with the rotation direction of the plurality of driven parts. As a result, the wave energy can be extracted as vibrations in all directions without limiting the direction of the fine vibration. That is, the wave energy propagated in the base portion can be taken out in the form of vibration (more specifically, resonance), and as a result, a plurality of driven portions can be rotated.

In an aspect of the driving device in which the excitation force is non-directional fine vibration or anisotropic fine vibration as non-directional vibration energy, the application unit is a rotation direction having an axis along the one direction as a central axis. You may comprise so that the said fine vibration produced by the force which acts on a different direction may be added.

According to this configuration, when applying the fine vibration, the application unit firstly has a direction different from the rotation direction having the axis along one direction as the central axis (that is, the rotation direction of the driven unit). Generate an acting force. As will be described in detail later with reference to the drawings, this force is applied to the base portion as fine vibration (in other words, wave energy). In other words, it is possible to apply a minute vibration (in other words, a minute vibration or wave energy generated by converting the force) caused by a force acting in a direction different from the rotation direction with the axis along one direction as the central axis. . Therefore, the various effects described above can be suitably enjoyed.

In an aspect of the driving device in which the excitation force is non-directional fine vibration or anisotropic fine vibration as non-directional vibration energy, the application unit is a force acting in a direction along the surface of the driven unit at rest It may be configured to apply the fine vibration generated by the above.

According to this configuration, when applying the fine vibration, the application unit firstly has a direction along the surface of the plurality of driven parts at rest (in other words, at the initial placement) (that is, in-plane direction). ) Is generated. As will be described in detail later with reference to the drawings, this force is applied to the base portion as fine vibration (in other words, wave energy). That is, it is possible to apply a minute vibration (in other words, a minute vibration or wave energy generated by converting the force) caused by a force acting in a direction along the surfaces of the plurality of driven parts at rest. Therefore, the various effects described above can be suitably enjoyed.

Such an operation and other advantages of the present embodiment will be clarified from examples described below.

As described above, according to the driving apparatus of the present embodiment, the base unit, the plurality of driven parts, the plurality of elastic parts, and the applying part are provided, and the applying part includes the first driven part. Slight vibration is applied so that the rotating phase is opposite to the rotating phase of the second driven part. Accordingly, the plurality of driven parts can be suitably rotated.

Hereinafter, embodiments of the drive device will be described with reference to the drawings. In the following, an example in which the driving device is applied to a MEMS scanner will be described.

(1) First Embodiment A MEMS scanner 100 according to a first embodiment will be described with reference to FIGS.

(1-1) Basic Configuration The basic configuration of the MEMS scanner 100 according to the first embodiment will be described with reference to FIG. FIG. 1 is a plan view conceptually showing the basic structure of the MEMS scanner 100 of the first embodiment.

As shown in FIG. 1, the MEMS scanner 100 of the first embodiment includes a base 110,

torsion bars

120a and 120b,

torsion bars

120c and 120d, a mirror 130a, a mirror 130c, and a drive source unit 160. ing.

The base 110 has a frame shape with a gap inside. That is, the base 110 has two sides extending in the Y-axis direction in FIG. 1 and two sides extending in the X-axis direction (that is, the axial direction perpendicular to the Y-axis) in FIG. It has a frame shape having a gap surrounded by two sides extending in the axial direction and two sides extending in the X-axis direction. In the example illustrated in FIG. 1, the base 110 has a square shape, but is not limited thereto, and other shapes (for example, a rectangular shape such as a rectangle or a circular shape) may be used. You may have. The base 110 is a structure that is the basis of the MEMS scanner 100 according to the first embodiment, and is fixed to a substrate or a support member (not shown) (in other words, the inside of the system called the MEMS scanner 100). Is preferably fixed).

Although FIG. 1 shows an example in which the base 110 has a frame shape, it goes without saying that it may have other shapes. For example, the base 110 may have a U-shape in which a part of the base 110 is an opening. Alternatively, for example, the base 110 may have a box shape with a gap inside. That is, the base 110 is defined by two surfaces distributed on a plane defined by the X axis and the Y axis, and the X axis and a Z axis (not shown) (that is, an axis orthogonal to both the X axis and the Y axis). Box having two planes distributed on a flat plane and two planes distributed on a plane defined by a Y-axis and a Z-axis (not shown) and a space surrounded by these six planes You may have a shape. Alternatively, the shape of the base 110 may be arbitrarily changed according to the manner in which the

mirrors

130a and 130c are arranged.

The torsion bar 120a 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 torsion bar 120a is arranged to extend in the direction of the Y axis in FIG. In other words, the torsion bar 120a 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 torsion bar 120a may have a shape having a short side extending in the Y-axis direction and a long side extending in the X-axis direction according to the setting state of the resonance frequency described later. One end 121 a of the torsion bar 120 a is connected to the side 111 inside the base 110. The other end 122a of the torsion bar 120a is connected to the side 131a of the mirror 130a that faces the side 111 inside the base 110 along the Y-axis direction.

The torsion bar 120b is an elastic member such as a spring made of, for example, silicon, copper alloy, iron alloy, other metal, resin, or the like. The torsion bar 120b is arranged so as to extend in the direction of the Y axis in FIG. In other words, the torsion bar 120b 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 torsion bar 120b may have a shape having a short side extending in the Y-axis direction and a long side extending in the X-axis direction according to the setting state of the resonance frequency described later. One end 121b of the torsion bar 120b is on the inner side 111 of the base 110 along the Y-axis direction (that is, the inner side 111 of the base 110 to which the one end 121a of the torsion bar 120a is connected). It is connected to the inner side 112 of the opposing base 110. The other end 122b of the torsion bar 120b is connected to the side 132a of the mirror 130a facing the side 112 inside the base 110 along the Y-axis direction.

The torsion bar 120c 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 torsion bar 120c is arranged to extend in the direction of the Y axis in FIG. In other words, the torsion bar 120c 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 torsion bar 120c may have a shape having a short side extending in the Y-axis direction and a long side extending in the X-axis direction in accordance with a setting state of a resonance frequency described later. One end 121 c of the torsion bar 120 c is connected to the side 111 inside the base 110. The other end 122c of the torsion bar 120c is connected to a side 131c of the mirror 130c that faces the side 111 inside the base 110 along the Y-axis direction.

The torsion bar 120d 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 torsion bar 120d is disposed so as to extend in the direction of the Y axis in FIG. In other words, the torsion bar 120d 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 torsion bar 120d may have a shape having a short side extending in the Y-axis direction and a long side extending in the X-axis direction according to the setting state of the resonance frequency described later. One end 121d of the torsion bar 120d is on the inner side 111 of the base 110 along the Y-axis direction (that is, the inner side 111 of the base 110 to which the one end 121c of the torsion bar 120c is connected). It is connected to the inner side 112 of the opposing base 110. The other end 122d of the torsion bar 120d is connected to the side 132c of the mirror 130c facing the inner side 112 of the base 110 along the Y-axis direction.

The mirror 130a is arranged to be suspended or supported by the

torsion bars

120a and 120b in the space inside the base 110. The mirror 130a is configured to rotate about the Y-axis direction as a central axis by the elasticity of the

torsion bars

120a and 120b.

The mirror 130c is arranged to be suspended or supported by the torsion bars 120c and 120d in the gap inside the base 110. The mirror 130c is configured to rotate about the Y-axis direction as a central axis by the elasticity of the torsion bars 120c and 120d.

The drive source unit 160 applies fine vibrations necessary for rotating the

mirrors

130 a and 130 c about the axis along the Y-axis direction to the base 110. In addition, as long as the drive source part 160 can apply a slight vibration to the base 110, the arrangement mode may be arbitrarily determined. Further, the force is not limited to the base 110, and is applied to other positions (for example, the torsion bar 120a, the torsion bar 120b, the torsion bar 120c, the torsion bar 120b, the mirror 130a, the mirror 130c, etc.). It may be configured such that a force can be applied to it.

More specifically, the drive source unit 160 is a drive source unit that applies a force due to an electromagnetic force, and is fixed to a coil 161 arranged along the frame shape of the base 110 and a base material (not shown). Magnetic pole 162. In this case, a desired voltage is applied to the coil 161 at a desired timing from a drive source unit control circuit (not shown). When a voltage is applied to the coil 161, a current flows, and electromagnetic interaction occurs between the coil 161 and the magnetic pole 162. As a result, electromagnetic force due to electromagnetic interaction is generated. This electromagnetic force is transmitted to the base 110 as a slight vibration.

Subsequently, the configuration of the back side of the base 110 (specifically, the side opposite to the base 110 shown in FIG. 1) will be described with reference to FIG. 2 is a plan perspective view showing the configuration of the back side of the base 110 (specifically, the side opposite to the base 110 shown in FIG. 1).

As shown in FIG. 2, ribs 119 protruding from the surface of the base 110 are formed in a partial region 110 a of the frame shape of the base 110. The rib 119 may be formed integrally with the base 110 or may be additionally arranged after the base 110 is formed. On the other hand, the rib 119 is not formed in the other partial area 110b of the frame shape of the base 110.

2, the rigidity of a part of the region 110a in the frame shape of the base 110 is higher than the rigidity of the other part of the region 110b in the frame shape of the base 110. In other words, the rib 119 realizes a state in which the rigidity of a part of the region 110a in the frame shape of the base 110 is higher than the rigidity of the other part of the region 110b in the frame shape of the base 110. It is preferable to be formed on the base 110 so that the That is, a state in which the rigidity of a part of the region 110a in the frame shape of the base 110 is higher than the rigidity of the other part of the region 110b in the frame shape of the base 110 can be realized. It is preferable that the formation position, size, mass, rigidity, density, and the like of the rib 119 are appropriately determined.

Alternatively, by the rib 119 shown in FIG. 2, the mass (or mass per unit length along the frame direction of the base 110) of a part of the region 110 a in the frame shape of the base 110 can be reduced. It becomes larger than the mass (or mass per unit length along the frame direction of the base 110) of some other regions 110b. Alternatively, the rib 119 can realize a state in which the mass of a part of the region 110a in the frame shape of the base 110 is larger than the mass of the other part of the region 110b in the frame shape of the base 110. It is preferable to be formed on the base 110 so as to be able to. That is, in order to realize a state in which the mass of a part of the region 110a in the frame shape of the base 110 is larger than the mass of the other part of the region 110b in the frame shape of the base 110, It is preferable that the formation position, size, mass, rigidity, density, and the like of the rib 119 are appropriately determined.

The region 110a where the rib 119 is formed and the region 110b where the rib 119 is not formed are in a direction (that is, a direction along the X axis) perpendicular to the respective rotation axes (that is, the Y axis) of the mirrors 130a and 130b. It is preferable to line up along.

FIG. 2 shows an example in which the rib 119 is formed on the back side of the base 110. However, the rib 119 may be formed on the front side of the base 110, may be formed on the side surface of the base 110, or may be formed on the inner surface of the base 110. Alternatively, by using a configuration other than the rib 119, the rigidity of the partial area 110a in the frame shape of the base 110 is higher than the rigidity of the other partial area 110b in the frame shape of the base 110. May be realized. Alternatively, by using a configuration other than the rib 119, the mass of a part of the region 110a in the frame shape of the base 110 is larger than the mass of the other part of the region 110b in the frame shape of the base 110. May be realized. For example, the above-described state may be realized by making the density and material of the base 110 different between the region 110a and the region 110b.

(1-2) Operation of the MEMS Scanner Next, with reference to FIG. 3, an operation mode (specifically, an operation mode for rotating the

mirrors

130a and 130c) of the MEMS scanner 100 of the first embodiment will be described. To do. FIG. 3 is a plan view conceptually showing an operation mode by the MEMS scanner 100 of the first embodiment.

During the operation of the MEMS scanner 100 of the first embodiment, a desired voltage is applied to the coil 161 at a desired timing from a drive source unit control circuit (not shown). When a voltage is applied to the coil 161, a current flows, and electromagnetic interaction occurs between the coil 161 and the magnetic pole 162. As a result, electromagnetic force due to electromagnetic interaction is generated. This electromagnetic force is transmitted to the base 110 as slight vibration (or wave energy).

Here, the direction of the electromagnetic force due to electromagnetic interaction is from the back side (the back side of the paper) to the near side (the front side of the paper) in FIG. This electromagnetic force itself is different from the rotation direction of the

mirrors

130a and 130c (that is, the rotation direction with the direction along the Y axis as the central axis). On the other hand, this electromagnetic force is transmitted to the base 110 as micro vibrations (in other words, wave energy having no directivity). More specifically, the drive source unit 160 applies, as wave energy, fine vibrations that propagate through the base 110 while eliminating the twist in the rotation direction of the base 110 itself to the base 110 that is the base. In other words, instead of applying a force that imparts a twist in the rotational direction to the base 110 itself, the drive source unit 160 transmits micro vibrations that propagate through the base 110 as energy (in other words, as wave energy that expresses the force). Add. Such fine vibration becomes a force having no directivity when propagating through the base 110. In other words, the wave energy propagating in the base 110 as micro vibrations propagates in the base 110 in an arbitrary direction. In addition, the base 110 to which such a minute vibration is applied becomes a medium for propagating the minute vibration (in other words, wave energy) rather than the object that the base 110 itself vibrates.

As a result, the slight vibration applied from the drive source unit 160 to the base 110 is transmitted from the base 110 to the

torsion bars

120a and 120b. After that, as shown in FIG. 3, the micro-vibration (in other words, wave energy) propagating through the base 110 rotates the

torsion bars

120a and 120b in a direction corresponding to the elasticity of the

torsion bars

120a and 120b themselves. Or rotate the mirror 130a. In other words, the micro vibration that has propagated through the base 110 appears in the form of rotation of the

torsion bars

120a and 120b and rotation of the mirror 130a. In other words, this wave energy can be taken out as vibrations in all directions without limiting the direction of micro vibrations. That is, the wave energy propagated in the base 110 can be extracted outside in the form of vibration (more specifically, resonance), and as a result, the mirror 130a can be rotated. As a result, as shown in FIG. 3, the mirror 130a rotates about the axis along the Y-axis direction as the central axis. More specifically, the mirror 130a repeats the rotation operation at the resonance frequency within a predetermined angle range (in other words, repeats the reciprocating motion of rotation within the predetermined angle range).

At this time, the mirror 130a rotates so as to resonate at a resonance frequency determined according to the mirror 130a and the

torsion bars

120a and 120b. More specifically, the mirror 130a is an inertia around the axis along the Y axis of the mirror 130a (more specifically, a suspended part including the mirror 130a and suspended by the

torsion bars

120a and 120b). It rotates so as to resonate at a resonance frequency determined according to the moment and the torsion spring constants of the

torsion bars

120a and 120b. For example, if the moment of inertia about the axis along the Y-axis of the mirror 130a is Ia and the torsion spring constant when the

torsion bars

120a and 120b are regarded as one spring is ka, the mirror 130a is ( 1 / (2π)) × √ (ka / Ia) resonance frequency (or (1 / (2π)) × √ (ka / Ia) N times or 1 / N times (where N Is rotated about the axis along the direction of the Y axis so as to resonate at a resonance frequency of 1). For this reason, the drive source unit 160 applies slight vibration in a manner synchronized with the resonance frequency so that the mirror 130a resonates at the resonance frequency described above.

Strictly speaking, the resonance frequency of the mirror 130a may change depending on the rigidity and mass (or moment of inertia) of the base supporting the rotating system including the rotating body called the mirror 130a. For example, the resonance frequency of the mirror 130a may change depending on the rigidity and mass (or moment of inertia) of the base 110 that supports a rotating system including a rotating body called the mirror 130a. Therefore, in consideration of the rigidity and mass (or moment of inertia) of the base supporting the mirror 130a, an equation (1 / (2π)) × √ (ka / Ia) (or a parameter specifying the equation) A resonance frequency obtained as a result of performing a predetermined correction operation on certain ka and Ia) may be handled as the actual resonance frequency of the mirror 130a.

Similarly, the slight vibration applied to the base 110 from the drive source unit 160 is transmitted from the base 110 to the torsion bars 120c and 120d. After that, as shown in FIG. 3, micro vibrations (in other words, wave energy) propagating through the base 110 rotate the

torsion bars

120 c and 120 d in a direction corresponding to the elasticity of the

torsion bars

120 c and 120 d themselves. Or rotate the mirror 130c. In other words, the micro vibration that has propagated through the base 110 appears in the form of rotation of the torsion bars 120c and 120d and rotation of the mirror 130c. In other words, this wave energy can be taken out as vibrations in all directions without limiting the direction of micro vibrations. That is, the wave energy propagated in the base 110 can be extracted outside in the form of vibration (more specifically, resonance), and as a result, the mirror 130c can be rotated. As a result, as shown in FIG. 3, the mirror 130c rotates about the axis along the Y-axis direction as the central axis. More specifically, the mirror 130c repeats the rotation operation at the resonance frequency within a predetermined angle range (in other words, the reciprocating motion of rotation within the predetermined angle range is repeated).

At this time, the mirror 130c rotates so as to resonate at a resonance frequency determined according to the mirror 130c and the torsion bars 120c and 120d. More specifically, the mirror 130c is an inertia around the axis along the Y axis of the mirror 130c (more specifically, a suspended portion including the mirror 130c and suspended by the torsion bars 120c and 120d). It rotates so as to resonate at a resonance frequency determined according to the moment and the torsion spring constants of the torsion bars 120c and 120d. For example, assuming that the moment of inertia about the axis along the Y-axis of the mirror 130c is Ic and the torsion spring constant kc when the torsion bars 120c and 120d are regarded as one spring is kc, 1 / (2π)) × √ (kc / Ic) specified by the resonance frequency (or (1 / (2π)) × √ (kc / Ic) N times or 1 / N times (where N Is rotated about the axis along the direction of the Y axis so as to resonate at a resonance frequency of 1). For this reason, the drive source unit 160 applies slight vibration in a manner synchronized with the resonance frequency so that the mirror 130c resonates at the resonance frequency described above.

Strictly speaking, the resonance frequency of the mirror 130a may change depending on the rigidity and mass (or moment of inertia) of the base supporting the rotating system including the rotating body called the mirror 130c. For example, the resonance frequency of the mirror 130a may change depending on the rigidity and mass (or moment of inertia) of the base 110 that supports a rotating system including a rotating body called the mirror 130c. Therefore, in consideration of the rigidity and mass (or moment of inertia) of the base supporting the mirror 130c, an equation (1 / (2π)) × √ (kc / Ic) (or a parameter for specifying the equation) A resonance frequency obtained as a result of performing a predetermined correction operation on a certain kc and Ic) may be handled as an actual resonance frequency of the mirror 130c.

In the first embodiment, it is preferable that the resonance frequency of the mirror 130a and the resonance frequency of the mirror 130c are the same. Specifically, it is preferable that (1 / (2π)) × √ (ka / Ia) = (1 / (2π)) × √ (kc / Ic). Alternatively, when the MEMS scanner 100 includes three or more mirrors 130, it is preferable that at least two resonance frequencies of the plurality of mirrors 130 are the same.

Here, with reference to FIG. 4, the non-directional force resulting from the fine vibration applied from the drive source unit 160 will be further described. FIG. 4 is a plan view for explaining a non-directional force caused by the micro vibration applied from the drive source unit 160. In the following description, in order to make the description easy to understand, the description will be given using the drive source unit 160 having a configuration different from the drive source unit 160 shown in FIG. However, the electromagnetic force as a minute vibration applied from the drive source unit 160 shown in FIG. 1 and the electromagnetic force as a minute vibration applied from the drive source unit 160 shown in FIG. 4 are actually the same force (that is, direction). Power without sex).

As shown in FIG. 4, the drive source unit 160 includes a transmission branch 160b and a first support plate 160-1c connected to the base 110 via the transmission branch 160b and facing each other along the direction of the Y axis. A first support plate 160-1c having first branches 160-1x and 160-1y, and a second support plate 160-2c connected to the base 110 via the transmission branch 160b, and in the direction of the Y-axis A second support plate 160-2c having second branches 160-2x and 160-2y facing each other along, and a first coil 160-1z wound around each of the first branches 160-1x and 160-1y, A second coil 160-2z wound around each of the second branches 160-2x and 160-2y. Further, it is assumed that the shapes and characteristics of the first branches 160-1x and 160-1y and the second branches 160-2x and 160-2y are the same, and the characteristics of the coil 160-1z wound around the first branch 160-1x ( For example, the number of turns, etc.) and the characteristics (eg, the number of turns, etc.) of the coil 160-1z wound around the first branch 160-1y are the same, and the coil 160-2z wound around the second branch 160-2x The characteristics (for example, the number of windings) and the characteristics (for example, the number of windings) of the coil 160-2z wound around the second branch 160-2y are the same.

Here, when an electric current is passed through the coils 160-1z and 160-2z wound around the first branches 160-1x and 160-1y and the second branches 160-2x and 160-2y, respectively, A force pulled in the direction of the first branch 160-1y and the second branch 160-2y with respect to the first branch 160-1x and the second branch 160-2x (that is, in the negative direction of the Y-axis, as shown in FIG. When a force acting in the direction toward the middle and lower side is generated, the first branch 160-1x and the second branch 160-2x are also applied to the first branch 160-1y and the second branch 160-2y. A force that is pulled in the direction (that is, a force acting in the positive direction of the Y axis and in the direction toward the upper side in FIG. 4) is generated. Since these forces are opposite to each other and have the same magnitude, the first branch 160-1x and the first branch 160-1y do not cause acceleration to the outside or generate acceleration themselves. Are joined at point P1 (in other words, point P1 on the transmission branch 160b) and point P2 (in other words, point P2 on the transmission branch 160b) where the second branch 160-2x and the second branch 160-2y are joined. Only fine vibrations are transmitted. As a result, the forces at points P1 and P2 are not directional. Similarly, the force that separates the first branch 160-1y and the second branch 160-2y from the first branch 160-1y and the second branch 160-2y by the electromagnetic interaction (that is, the positive direction of the Y-axis). 4), the first branch 160-1x and the second branch 160 are also applied to the first branch 160-1y and the second branch 160-2y. −2x is generated (that is, a force acting in the negative direction of the Y axis and in the downward direction in FIG. 4). Since these forces are opposite to each other and have the same magnitude, the first branch 160-1x and the first branch 160-1y do not cause acceleration to the outside or generate acceleration themselves. Only a slight vibration is transmitted to the point P1 where the two parts are joined and the point P2 where the second branch 160-2x and the second branch 160-2y are joined. As a result, the forces at points P1 and P2 are not directional.

However, according to the experiment by the inventors of the present application, a fine vibration (that is, a wave energy having no directivity) propagates in the base 110 according to the above configuration, and as a result, the

mirrors

130a and 130c have the Y axis. It has been found that it rotates about the axis along the direction as the central axis. That is, the micro-vibration applied by the drive source unit 160 propagates in the base 110 as the above-described non-directional force (in other words, wave energy), so that the

mirrors

130a and 130c have an axis along the Y-axis direction. It has been found that it rotates as a central axis.

Thus, in the first embodiment, the mirror 130a is rotated about the axis along the Y-axis direction as the central axis so that the mirror 130a resonates at a resonance frequency determined according to the mirror 130a and the

torsion bars

120a and 120b. Can be made. Further, in the first embodiment, the mirror 130c is rotated about the axis along the Y-axis direction as a central axis so that the mirror 130c resonates at a resonance frequency determined according to the mirror 130c and the torsion bars 120c and 120d. Can do. That is, in the first embodiment, the

mirrors

130a and 130c self-resonate with the Y axis as the central axis.

Here, “resonance” is a phenomenon in which infinite displacement occurs due to repeated infinitesimal force. Therefore, even if the force applied to rotate the

mirrors

130a and 130c is reduced, the rotation range of the

mirrors

130a and 130c (in other words, the amplitude in the rotation direction) can be increased. That is, the force required to rotate the

mirrors

130a and 130c can be relatively reduced. For this reason, it is possible to reduce the amount of electric power necessary for applying the force necessary to rotate the

mirrors

130a and 130c. Therefore, the

mirrors

130a and 130c can be moved more efficiently, and as a result, low power consumption of the MEMS scanner 100 can be realized.

In addition, in the first embodiment, a force having no directionality is applied.

Here, as a comparative example, a configuration in which the

mirrors

130a and 130c are rotationally driven by applying a so-called directional force (for example, the base 110 itself is largely twisted in the rotational direction of the

mirrors

130a and 130c, and the torsion is performed. The

torsion bars

120a and 120b, the torsion bars 120c and 120d, and the

mirrors

130a and 130c are directly driven to rotate the

mirrors

130a and 130c. In this case, a force having a directionality to rotate the

mirrors

130a and 130c about the axis along the Y-axis direction (that is, the base 110 is rotated about the axis along the Y-axis direction as the central axis). It is necessary to apply a twisting force from a certain drive source unit 160. For this reason, the arrangement position of the drive source unit 160 must be appropriately set so that a force having such directionality can be applied. That is, when applying a force having directionality, the arrangement position of the drive source unit 160 is limited depending on the direction in which the force is applied.

However, in the first embodiment, since a non-directional force due to micro vibration is applied, the arrangement position of the drive source unit 160 is not limited. In other words, since a non-directional force due to micro vibration is applied, the arrangement position of the drive source unit 160 is not limited depending on the direction of rotation of the

mirrors

130a and 130c. That is, no matter what the position of the drive source unit 160 is set, the slight vibration (that is, nondirectional force) applied from the drive source unit 160 causes the

torsion bars

120a and 120b and the torsion bar 120c. And 120d, the

mirrors

130a and 130c can be rotated about the axis along the Y-axis direction as the central axis. Thereby, the design freedom of the MEMS scanner 100 can be relatively increased. This is very advantageous in practice for MEMS scanners where the size or design constraints of each component are large.

Further, in the first embodiment, since the rib 119 is formed on the back side of the base 110, the base 110 itself deforms and vibrates so as to wave due to the slight vibration applied from the drive source unit 160. Hereinafter, with reference to FIG. 5, the deformation | transformation aspect of the base 110 is demonstrated. FIG. 5 is a side view showing the deformation mode of the base 110 in association with the rotation mode of the mirrors 130a and 130b. 5 shows a side view when the base 110 and the

mirrors

130a and 130c are observed from the direction of the arrow “III” shown in FIG.

As shown in FIG. 5A, the base 110 is not deformed and the mirrors 130a and 130b are not rotating in a state where the vibration is not applied to the base 110 from the drive source unit 160.

As shown in FIG. 5B, when a slight vibration is applied from the drive source unit 160 to the base 110, the region 110a in which the rib 119 is formed has a relatively high rigidity and is bent by the slight vibration. On the other hand, since the region 110b where the rib 119 is not formed has a relatively low rigidity, it is easy to bend by slight vibration. As a result, the base 110 deforms and vibrates so as to wave in the direction of the X-axis, with the region 110a where the rib is formed as a node and the region 110b where the rib 119 is not formed as a belly. More specifically, the base 110 vibrates while deforming its appearance like a standing wave having a region 110a where the rib 119 is formed as a node and a region 110b where the rib 119 is not formed as an antinode. In the example shown in FIG. 5B, the base 110 is deformed and oscillated so as to be bent from the center. However, the base 110 may be deformed and oscillated in other deformation modes (for example, a deformation mode having more nodes).

The deformation vibration of the base 110 in the first embodiment is realized by forming the rib 119 at an appropriate location. Therefore, the above-described rib 119 has the base 110 such that the base 110 is deformed and oscillated along the direction of the X-axis with the region 110a where the rib is formed as a node and the region 110b where the rib 119 is not formed as an antinode. It is preferably formed at an appropriate location on 110. At this time, it is preferable that a portion where the

torsion bars

120a and 120b and the torsion bars 120c and 120d are connected corresponds to the region 110a. For example, in the rib 119 described above, a portion having a relatively high bending rigidity along the X-axis direction and a portion having a relatively low bending rigidity along the X-axis direction appear in order along the X-axis direction. As such, it is preferably formed at an appropriate location on the base 110. Alternatively, for example, in the rib 119 described above, a portion having a relatively high bending rigidity along the X-axis direction and a portion having a relatively low bending rigidity along the X-axis direction are along the X-axis direction. It is formed in an appropriate place on the base 110 so that the places where the

torsion bars

120a and 120b and the torsion bars 120c and 120d are connected become the area 110a and the other places become the area 110b. Is preferred.

At this time, depending on the period of fine vibration applied from the drive source unit 160, the base 110 undergoes deformation vibration so as to resonate. Here, in the first embodiment, the resonance frequency in the deformation vibration of the base 110 is preferably the same as the resonance frequency of the mirrors 130a and 130b. In other words, the characteristics of the base 110 are preferably determined so that the base 110 deforms and vibrates at the same resonance frequency as that of the mirrors 130a and 130b. For example, characteristics of the rib 119 formed on the back side of the base 110 so as to deform and vibrate at the same resonance frequency as the resonance frequency of the mirrors 130a and 130b (for example, the formation position, size, mass, rigidity, density, etc. Etc.) is preferably defined.

The resonance frequency in the deformation vibration of the base 110 is such that the structure including the base 110 and the rib 119 is regarded as one spring system, the mass added to the spring system is M, and the spring constant of the spring system is k. In this case, it is specified by (1 / (2π)) × √ (k / M). However, if the spring system is a one-degree-of-freedom spring system in which one mass structure is connected to one spring (in other words, the natural frequency is one and the natural vibration mode is one). , (1 / (2π)) × √ (k / M) resonant frequency can be employed. On the other hand, if the spring system is a two-degree-of-freedom spring system in which two mass structures are connected to one spring, “k” at a resonance frequency of (1 / (2π)) × √ (k / M). "," M "and the like are preferably corrected. When the structure including the base 110 and the rib 119 is regarded as one spring system, the mass M added to the spring system and the spring constant k of the spring system depend on the rigidity and mass of the base 110. Determined. In the first embodiment, the rigidity and mass of the base 110 are adjusted by the ribs 119. For this reason, the resonance frequency of the base 110 is substantially determined by the characteristics of the rib 119 described above.

Also, the resonance frequency in the deformation vibration of the base 110 is specified by the equation (1 / (2π)) × √ (k / M). However, strictly speaking, the resonance frequency in the deformation vibration of the base 110 may change depending on the rigidity and mass (or moment of inertia) of the base supporting the vibration system including the deformation vibration body called the base 110. For this reason, after considering the rigidity and mass (or moment of inertia) of the base supporting the base 110, an equation (1 / (2π)) × √ (k / M) (or a parameter specifying the equation) A resonance frequency obtained as a result of performing a predetermined correction operation on a certain k and M) may be handled as a resonance frequency in an actual deformation vibration of the base 110.

Further, the resonance in the deformation vibration of the base 110 is replaced by defining the spring system related to the deformation vibration of the base 110 as a two-degree-of-freedom spring system in which two mass structures are connected to one spring. It may be defined by considering it as a higher-order resonance mode of a plate-like member called the base 110.

Here, as described above, fine vibration is applied from the drive source unit 160 in a manner synchronized with the resonance frequency so that the

mirrors

130a and 130c resonate at the resonance frequency. Therefore, the base 110 is deformed and oscillated so as to resonate due to the application of such fine vibration. That is, as shown in FIG. 5A to FIG. 5F in time series, the base 110 is deformed and oscillated so as to have an appearance like a standing wave with both ends open. That is, the base 110 has an appearance such that a standing wave appears along a direction orthogonal to the rotation axes of the

mirrors

130a and 130c (that is, the direction of the X axis).

When the base 110 is deformed and vibrated in this manner, the base 110 on the mirror 130a side (specifically, the relatively left base 110 in FIGS. 5A to 5F) is deformed. This is opposite to the deformation mode of the base 110 on the mirror 130c side (specifically, the relatively right-side base 110 in FIGS. 5A to 5F). For example, when the base 110 on the mirror 130a side is deformed counterclockwise around the rotation axis of the mirror 130a (for example, when deformed as shown in FIGS. 5A to 5C). The base 110 on the mirror 130c side is deformed clockwise around the rotation axis of the mirror 130c. Similarly, for example, when the base 110 on the mirror 130a side is deformed clockwise around the rotation axis of the mirror 130a (for example, as illustrated in FIGS. 5D to 5F). ), The base 110 on the mirror 130c side is deformed counterclockwise around the rotation axis of the mirror 130c. Accordingly, since the resonance frequencies of the

mirrors

130a and 130c are the same, the

mirrors

130a and 130c have the rotation phase of the mirror 130a and the rotation phase of the mirror 130c reversed in phase with the deformation vibration of the base 110. Rotate to In other words, the

mirrors

130a and 130c rotate so that the phase of rotation of the mirror 130a is shifted by 180 ° with respect to the phase of rotation of the mirror 130c. In other words, the

mirrors

130a and 130c rotate so that the deviation between the rotation phase of the mirror 130a and the rotation phase of the mirror 130c is fixed at 180 °. The relationship between the phase of rotation of the mirror 130a and the phase of rotation of the mirror 130c is as shown in FIGS. 5 (c) to 5 (f). Even if it exists, it is established.

It should be noted that the deviation between the phase of rotation of the mirror 130a and the phase of deformation vibration of the base 110 may vary with time or may be fixed. Similarly, the deviation between the phase of rotation of the mirror 130c and the phase of deformation vibration of the base 110 may vary with time or may be fixed. The above description with reference to FIG. 5 shows an example in which the deviation between the phase of rotation of the

mirrors

130a and 130c and the phase of deformation vibration of the base 110 is fixed. However, even if the deviation between the phase of the rotation of the

mirrors

130a and 130c and the phase of the deformation vibration of the base 110 fluctuates, the

mirrors

130a and 130c may change the phase of the rotation of the mirror 130a and the rotation of the mirror 130c. There is no change in rotating so that the phases are opposite to each other.

Thus, according to the first embodiment, the

mirrors

130a and 130c can be rotated so that the rotation phase of the mirror 130a and the rotation phase of the mirror 130c are opposite to each other. That is, the two

mirrors

130a and 130c can be rotated (that is, driven) in opposite phases while being synchronized. Therefore, compared to a MEMS scanner that rotates one mirror 130 at the reference frequency f, the two

mirrors

130a and 130c are handled as one mirror 130 at a frequency 2f that is twice the reference frequency f (in other words, A state similar to the state of rotating one mirror 130 (with a period of 1/2) can be realized. In other words, even if each of the

mirrors

130a and 130c is rotated at a frequency f / 2 that is half the reference frequency f, the two

mirrors

130a and 130c are handled as one mirror 130, so that one mirror at the reference frequency f. A state similar to the state of rotating 130 can be realized. For example, a mirror 130 that can be rotated ± X ° in one cycle with the state at rest being 0 ° will be described as an example. If one mirror 130 is used, a period of one cycle is required to use an angle from −X ° to X °. On the other hand, if two

mirrors

130a and 130c rotating in opposite phases are used, the mirror 130a rotates from 0 ° to X ° and the mirror 130c rotates from 0 ° to −X ° in a half cycle. For this reason, according to the first embodiment, in order to use the angle from −X ° to X °, one period is not necessarily required, and a half period is sufficient, for example. Therefore, even if the frequency for driving each of the

mirrors

130a and 130c is lowered, the driving frequency of the mirror 130 when the

mirrors

130a and 130c are handled like one mirror 130 is not lowered.

FIG. 5 shows an example in which the rotation phase of each of the

mirrors

130a and 130c and the phase of deformation vibration of the base 110 are reversed. However, as shown in FIG. 6, the phase of rotation of each of the

mirrors

130 a and 130 c and the phase of deformation vibration of the base 110 may be in phase. Even if the phase of rotation of each of the

mirrors

130a and 130c and the phase of deformation vibration of the base 110 are in phase, the phase of deformation vibration of the base 110 may be in phase. Various effects that can be enjoyed when the phase of rotation of each of the

mirrors

130a and 130c and the phase of deformation vibration of the base 110 are in opposite phases can be suitably enjoyed.

In the first embodiment described above, an example is described in which fine vibration is used as the force for rotating the

mirrors

130a and 130c (that is, applied from the drive source unit). However, any force other than the slight vibration may be used as the force for rotating the

mirrors

130a and 130c. For example, the mirror 130a and the mirror 130a and the “driving method in which torsional vibration is generated in the mirror using the plate wave of the substrate (for example, Lamb wave resonance piezoelectric driving method)” described in JP-A-2006-293116 is disclosed. 130c may be rotated. Alternatively, for example, as a force for rotating the

mirrors

130a and 130c, a directional force acting in the direction of directly rotating the

mirrors

130a and 130c may be used. In other words, for example, as a force for rotating the

mirrors

130a and 130c, a directional force acting in a direction that directly twists the

torsion bars

120a and 120b and 120c and 120d may be used. The same applies to the following second to third embodiments.

(2) Second Embodiment Next, the MEMS scanner 101 of the second embodiment will be described with reference to FIG. FIG. 7 is a plan view conceptually showing the basic structure of the MEMS scanner 101 of the second embodiment. In addition, about the structure same as the MEMS scanner 100 of the above-mentioned 1st Example, the detailed description is abbreviate | omitted by attaching | subjecting the same referential mark.

As shown in FIG. 7, the MEMS scanner 101 of the second embodiment is similar to the MEMS scanner 100 of the first embodiment, in that a base 110,

torsion bars

120a and 120b,

torsion bars

120c and 120d, a mirror 130a, , And a mirror 130c. The MEMS scanner 101 according to the second embodiment includes a drive source unit 140 that applies force (microvibration) due to the piezoelectric effect, instead of the drive source unit 160 that applies force (microvibration) due to electromagnetic force. .

The drive source unit 140 includes a first piezoelectric element 140-1a, a second piezoelectric element 140-2a, a transmission branch 140b, a first gap 140-1d, and is fixed to the base 110 via the transmission branch 140b. A first support plate 140-1c and a second support plate 140-2c having a second gap 140-2d and being fixed to the base 110 via the transmission branch 140b are provided. On the first support plate 140-1c, the first piezoelectric element 140-1a is sandwiched by the first branches 140-1e and 140-1f facing each other defined by the first gap 140-1d. On the second support plate 140-2c, the second piezoelectric element 140-2a is sandwiched between the opposing second branches 140-2e and 140-2f defined by the second gap 140-2d. By applying a voltage to the first piezoelectric element 140-1a via an electrode (not shown), the first piezoelectric element 140-1a changes its shape. This change in the shape of the first piezoelectric element 140-1a causes a change in the shape of the first branches 140-1e and 140-1f. As a result, changes in the shapes of the first branches 140-1e and 140-1f are transmitted to the base 110 through the transmission branch 140b as fine vibration (or wave energy) as will be described in detail later. Similarly, by applying a voltage to the second piezoelectric element 140-2a via an electrode (not shown), the second piezoelectric element 140-2a changes its shape. This change in the shape of the second piezoelectric element 140-2a causes a change in the shape of the second branches 140-2e and 140-2f. As a result, changes in the shapes of the second branches 140-2e and 140-2f are transmitted to the base 110 through the transmission branch 140b as fine vibration (or wave energy) as will be described in detail later.

Such micro-vibration applied from the drive source unit 140 is a force having no direction described with reference to FIG. Therefore, according to the MEMS scanner 101 of 2nd Example, the effect similar to the various effects which the MEMS scanner 100 of 1st Example mentioned above can enjoy suitably can be enjoyed.

(3) Third Embodiment Next, the MEMS scanner 102 of the third embodiment will be described with reference to FIG. FIG. 8 is a plan view conceptually showing the basic structure of the MEMS scanner 102 of the third embodiment. In addition, about the structure same as the MEMS scanner 100 of the above-mentioned 1st Example, the detailed description is abbreviate | omitted by attaching | subjecting the same referential mark.

As shown in FIG. 7, the MEMS scanner 102 of the third embodiment is similar to the MEMS scanner 100 of the first embodiment, in that a base 110,

torsion bars

120a and 120b,

torsion bars

120c and 120d, a mirror 130a, , And a mirror 130c. The MEMS scanner 102 according to the third embodiment includes a drive source unit 150 that applies a force (microvibration) due to an electrostatic force, instead of the drive source unit 160 that applies a force (microvibration) due to electromagnetic force. .

The drive source unit 150 has a comb-like first electrode 151 disposed along the outer side of the base 110 and a comb-like shape that is fixed to a base material (not shown) and distributed between the first electrodes 151. The second electrode 152 is provided. In this case, a desired voltage is applied to the first electrode 151 (or the second electrode 152) at a desired timing from a drive source unit control circuit (not shown). Due to the potential difference between the first electrode 151 and the second electrode 152, an electrostatic force (in other words, Coulomb force) is generated between the first electrode 151 and the second electrode 152. As a result, electrostatic force is generated. This electrostatic force is transmitted to the base 110 as a slight vibration.

Such micro-vibration applied from the driving source unit 150 is a force having no direction described with reference to FIG. Therefore, according to the MEMS scanner 102 of 3rd Example, the effect similar to the various effects which the MEMS scanner 100 of 1st Example mentioned above can enjoy can be enjoyed suitably.

(4) Fourth Embodiment Next, a fourth embodiment of the MEMS scanner will be described with reference to FIGS.

(4-1) Basic Configuration First, the basic configuration of the MEMS scanner 103 according to the fourth embodiment will be described with reference to FIG. FIG. 9 is a plan view conceptually showing the basic structure of the MEMS scanner 103 of the fourth embodiment.

As shown in FIG. 9, the MEMS scanner 103 of the fourth embodiment includes a first base 110-1, first torsion bars 120a-1 and 120b-1, a second base 110-2, and a second torsion bar. 120a-2 and 120b-2, second torsion bars 120c-2 and 120d-2, a mirror 130a, a mirror 130c, and a drive source unit 160.

The first base 110-1 has a frame shape with a gap inside. That is, the first base 110-1 has two sides extending in the Y-axis direction in FIG. 9 and two sides extending in the X-axis direction (that is, the axial direction perpendicular to the Y-axis) in FIG. And a frame shape having a gap surrounded by two sides extending in the Y-axis direction and two sides extending in the X-axis direction. In the example shown in FIG. 9, the first base 110-1 has a square shape. However, the first base 110-1 is not limited to this. For example, other shapes (for example, a rectangular shape such as a rectangle or a circular shape) Shape etc.). The first base 110-1 is a structure that is the basis of the MEMS scanner 103 of the fourth embodiment, and is fixed to a substrate or a support member (not shown) (in other words, the MEMS scanner 103). It is preferably fixed inside the system).

Although FIG. 9 shows an example in which the first base 110-1 has a frame shape, it goes without saying that the first base 110-1 may have other shapes. For example, the first base 110-1 may have a U-shape in which a part of the first base 110-1 is an opening. Alternatively, for example, the first base 110-1 may have a box shape with a gap inside. That is, the first base 110-1 is orthogonal to the two surfaces distributed on the plane defined by the X axis and the Y axis, and the Z axis (not shown) (that is, both the X axis and the Y axis). 2 planes distributed on a plane defined by the axis) and two planes distributed on a plane defined by the Y axis and a Z axis (not shown) and surrounded by these 6 planes You may have the box shape which has a space | gap. Alternatively, the shape of the first base 110-1 may be arbitrarily changed according to the manner in which the

mirrors

130a and 130c are arranged.

The first torsion bar 120a-1 is an elastic member such as a spring made of, for example, silicon, copper alloy, iron-based alloy, other metal, resin, or the like. The first torsion bar 120a-1 is disposed so as to extend in the direction of the X axis in FIG. In other words, the first torsion bar 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 torsion bar 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, depending on the setting condition of the resonance frequency described later. Also good. One end 121a-1 of the first torsion bar 120a-1 is connected to the inner side 115-1 of the first base 110-1. The other end 122a-1 of the first torsion bar 120a-1 is an outer side of the second base 110-2 that faces the inner side 115-1 of the first base 110-1 along the X-axis direction. 117-2.

The first torsion bar 120b-1 is an elastic member such as a spring made of, for example, silicon, copper alloy, iron alloy, other metal, resin, or the like. The first torsion bar 120b-1 is disposed so as to extend in the direction of the X axis in FIG. In other words, the first torsion bar 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 torsion bar 120b-1 has a short shape extending in the X-axis direction and a long shape extending in the Y-axis direction, depending on the setting condition of the resonance frequency described later. Also good. One end 121b-1 of the first torsion bar 120b-1 is located on the inner side (in other words, a region portion) 115-1 (that is, the first torsion bar) along the X-axis direction. The bar 120a-1 is connected to the inner side 116-1 of the first base 110-1 opposite to the inner side 115-1) of the first base 110-1 to which one end 121a-1 is connected. . The other end 122b-1 of the first torsion bar 120b-1 is an outer side of the second base 110-2 that faces the inner side 116-1 of the first base 110-1 along the X-axis direction. It is connected to 118-2.

The second base 110-2 has a frame shape with a gap inside. That is, the second base 110-2 has two sides extending in the Y-axis direction in FIG. 9 and two sides extending in the X-axis direction (that is, the axis direction orthogonal to the Y-axis) in FIG. And a frame shape having a gap surrounded by two sides extending in the Y-axis direction and two sides extending in the X-axis direction. In the example shown in FIG. 9, the second base 110-2 has a square shape. However, the second base 110-2 is not limited to this. For example, the second base 110-2 has other shapes (for example, a rectangular shape such as a rectangle or a circular shape). Shape etc.).

The second base 110-2 is arranged to be suspended or supported by the first torsion bars 120a-1 and 120b-1 in the space inside the first base 110-1. The second base 110-2 is configured to rotate about the X-axis direction as a central axis by the elasticity of the first torsion bars 120a-1 and 120b-1.

Although FIG. 9 shows an example in which the second base 110-2 has a frame shape, it goes without saying that the second base 110-2 may have other shapes. For example, the second base 110-2 may have a U-shape in which a part of the second base 110-2 is an opening. Alternatively, for example, the second base 110-2 may have a box shape with a gap inside. That is, the second base 110-2 is orthogonal to the two surfaces distributed on the plane defined by the X axis and the Y axis, and the Z axis (not shown) (that is, both the X axis and the Y axis). 2 planes distributed on a plane defined by the axis) and two planes distributed on a plane defined by the Y axis and a Z axis (not shown) and surrounded by these 6 planes You may have the box shape which has a space | gap. Alternatively, the shape of the second base 110-2 may be arbitrarily changed according to the manner in which the

mirrors

130a and 130c are arranged.

The second torsion bar 120a-2 is an elastic member such as a spring made of, for example, silicon, copper alloy, iron-based alloy, other metal, resin, or the like. Second torsion bar 120a-2 is arranged to extend in the direction of the Y-axis in FIG. In other words, the second torsion bar 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 torsion bar 120a-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, depending on the setting state of the resonance frequency described later. Also good. One end 121a-2 of the second torsion bar 120a-2 is connected to the inner side 111-2 of the second base 110-2. The other end 122a-2 of the second torsion bar 120a-2 is connected to one side 131a of the mirror 130a facing the side 111-2 on the inner side of the second base 110-2 along the Y-axis direction. The

The second torsion bar 120b-2 is a member having elasticity such as a spring made of, for example, silicon, copper alloy, iron alloy, other metal, resin, or the like. Second torsion bar 120b-2 is arranged to extend in the direction of the Y-axis in FIG. In other words, the second torsion bar 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 torsion bar 120b-1 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, depending on the setting state of the resonance frequency described later. Also good. One end 121b-2 of the second torsion bar 120b-2 is located on the inner side 111-2 of the second base 110-2 along the Y-axis direction (that is, one end of the second torsion bar 120a-2). It is connected to the inner side 112-2 of the second base 110-2 opposite to the inner side 111-2) of the second base 110-2 to which the end 121a-2 is connected. The other end 122b-2 of the second torsion bar 120b-2 is connected to the other side 132a of the mirror 130a facing the side 112-2 on the inner side of the second base 110-2 along the Y-axis direction. The

The second torsion bar 120c-2 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 second torsion bar 120c-2 is disposed so as to extend in the Y-axis direction in FIG. In other words, the second torsion bar 120c-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 torsion bar 120c-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 121c-2 of the second torsion bar 120c-2 is connected to the inner side 111-2 of the second base 110-2. The other end 122c-2 of the second torsion bar 120c-2 is connected to one side 131c of the mirror 130c facing the inner side 111-2 of the second base 110-2 along the Y-axis direction. The

The second torsion bar 120d-2 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 second torsion bar 120d-2 is disposed so as to extend in the Y-axis direction in FIG. In other words, the second torsion bar 120d-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 torsion bar 120d-1 has a shape having a short side extending in the Y-axis direction and a long side extending in the X-axis direction according to the setting state of the resonance frequency described later. Also good. One end 121d-2 of the second torsion bar 120d-2 extends along the Y-axis direction along the side 111-2 inside the second base 110-2 (that is, one end of the second torsion bar 120c-2). It is connected to the inner side 112-2 of the second base 110-2 opposite to the inner side 111-2) of the second base 110-2 to which the end 121c-2 is connected. The other end 122d-2 of the second torsion bar 120d-2 is connected to the other side 132c of the mirror 130c facing the inner side 112-2 of the second base 110-2 along the Y-axis direction. The

The mirror 130a is arranged to be suspended or supported by the second torsion bars 120a-2 and 120b-2 in the gap inside the second base 110-2. The mirror 130a is configured to rotate about the Y-axis direction as a central axis by the elasticity of the second torsion bars 120a-2 and 120b-2.

The mirror 130c is arranged to be suspended or supported by the second torsion bars 120c-2 and 120d-2 in the gap inside the second base 110-2. The mirror 130c is configured to rotate about the Y-axis direction as a central axis by the elasticity of the second torsion bars 120c-2 and 120d-2.

The drive source unit 160 applies to the second base 110-2 a fine vibration necessary to rotate the

mirrors

130a and 130c about the axis along the Y-axis direction as a central axis. As long as the drive source unit 160 can apply a slight vibration to the second base 110-2, the arrangement mode may be arbitrarily determined. Further, the present invention is not limited to applying force to the second base 110-2, and may be configured to apply force to other positions (for example, the first base 110-1).

More specifically, the drive source unit 160 is a drive source unit that applies a force due to electromagnetic force, and includes a coil 161 arranged along the frame shape of the second base 110-2, and the first base 110. Magnetic poles 162a to 162c fixed to -1. In this case, a desired voltage is applied to the coil 161 at a desired timing from a drive source unit control circuit (not shown). By applying a voltage to the coil 161, a current flows, and electromagnetic interaction occurs between the coil 161 and the magnetic poles 162a to 162c. As a result, electromagnetic force due to electromagnetic interaction is generated. This electromagnetic force is transmitted to the second base 110-2 as a slight vibration.

The magnetic pole 162a is a side 110-2 on one side of the second base 110-2 and a region between the mirror 130a and the mirror 130c (that is, the antinode of deformation vibration in the second base 110-2). It is preferable to be arranged adjacent to the region. On the other hand, the

magnetic poles

162b and 162c are regions located on the opposite side of the magnetic pole 162a with respect to the rotation axis of the second base 110-2, and the second base 110-2 (or the mirror 130a and the mirror 130c are connected). ) It is preferably arranged at a position sandwiched along the direction of the Y axis.

Subsequently, the configuration of the back side of the second base 110-2 (specifically, the opposite side of the second base 110-2 shown in FIG. 9) will be described with reference to FIG. FIG. 10 is a plan perspective view showing the configuration of the back side of the second base 110-2 (specifically, the side opposite to the second base 110-2 shown in FIG. 9).

As shown in FIG. 10, ribs 119 protruding from the surface of the second base 110-2 are formed in a partial region 110a of the frame shape of the second base 110-2. The rib 119 may be formed integrally with the second base 110-2, or may be additionally disposed after the second base 110-2 is formed. On the other hand, the rib 119 is not formed in the other partial area 110b of the frame shape of the second base 110-2.

By the rib 119 shown in FIG. 10, the rigidity of a part of the region 110a in the frame shape of the second base 110-2 is set to the rigidity of the other part of the region 110b of the frame shape of the second base 110-2. Higher than. In other words, in the rib 119, the rigidity of a part of the region 110a in the frame shape of the second base 110-2 is higher than the rigidity of the other part of the region 110b in the frame shape of the second base 110-2. It is preferable that the second base 110-2 be formed so that a higher state can be realized. That is, the rigidity of a part of the region 110a in the frame shape of the second base 110-2 is higher than the rigidity of the other part of the region 110b in the frame shape of the second base 110-2. It is preferable that the formation position, size, mass, rigidity, density, density, and the like of the ribs 119 are appropriately determined so that they can be realized.

Alternatively, by the rib 119 shown in FIG. 10, the mass of a part of the region 110a in the frame shape of the second base 110-2 (or the mass per unit length along the frame direction of the second base 110-2). Is larger than the mass of the other partial region 110b in the frame shape of the second base 110-2 (or the mass per unit length along the frame direction of the second base 110-2). Alternatively, the rib 119 may be configured such that the mass of a part of the region 110a in the frame shape of the second base 110-2 is larger than the mass of the other part of the region 110b in the frame shape of the second base 110-2. It is preferable that the second base 110-2 be formed so that a large state can be realized. That is, the mass of the partial area 110a in the frame shape of the second base 110-2 is larger than the mass of the other partial area 110b in the frame shape of the second base 110-2. It is preferable that the formation position, size, mass, rigidity, density, density, and the like of the ribs 119 are appropriately determined so that they can be realized.

FIG. 10 shows an example in which the rib 119 is formed on the back side of the second base 110-2. However, the rib 119 may be formed on the front side of the second base 110-2, may be formed on the side surface of the second base 110-2, or may be formed on the inner surface of the second base 110-2. Also good. Alternatively, by using a configuration other than the rib 119, the rigidity of a part of the region 110a in the frame shape of the second base 110-2 is set to be a part of the other part of the frame shape of the second base 110-2. You may implement | achieve the state which becomes higher than the rigidity of 110b. Alternatively, by using a configuration other than the rib 119, the mass of a part of the region 110a in the frame shape of the second base 110-2 may be changed to the other part of the frame shape of the second base 110-2. You may implement | achieve the state which becomes larger than the mass of 110b. For example, the above-described state may be realized by making the density and material of the second base 110-2 different between the region 110a and the region 110b.

(4-2) Operation of MEMS Scanner Next, with reference to FIG. 11, an operation mode (specifically, an operation mode for rotating the

mirrors

130 a and 130 c) of the MEMS scanner 103 of the fourth embodiment will be described. To do. FIG. 11 is a plan view conceptually showing an operation mode of the MEMS scanner 103 according to the fourth embodiment.

During the operation of the MEMS scanner 103 of the fourth embodiment, a desired voltage is applied to the coil 161 at a desired timing from a drive source unit control circuit (not shown). By applying a voltage to the coil 161, a current flows, and electromagnetic interaction occurs between the coil 161 and the magnetic poles 162a to 162c. As a result, electromagnetic force due to electromagnetic interaction is generated. This electromagnetic force is transmitted to the second base 110-2 as fine vibration (or wave energy).

Here, the direction of the electromagnetic force due to the electromagnetic interaction between the coil 161 and the magnetic pole 162a 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 161 and the magnetic pole 162b is from the front side to the back side in FIG. The direction of the electromagnetic force due to the electromagnetic interaction between the coil 161 and the magnetic pole 162c is from the front side to the back side in FIG. As a result, as shown in FIG. 11, this electromagnetic force rotates the first torsion bars 120a-1 and 120b-1 in the direction according to the elasticity of the first torsion bars 120a-1 and 120b-1 itself. Or rotating the second base 110-2. As a result, as shown in FIG. 11, the second base 110-2 rotates about the axis along the X-axis direction as the central axis.

It should be noted that the second base 110-2 may repeat the rotation operation within the predetermined angle range at the same frequency as the resonance frequency of

mirrors

130a and 130c, which will be described later, or at a frequency lower or higher than the resonance frequency. For example, when the MEMS scanner 103 of the fourth embodiment is applied to a display (or a head-mounted display), the second base 110-2 has a frequency (for example, 60 Hz) corresponding to the scanning period or frame rate of the display, for example. ) May be repeated.

Alternatively, the second base 110-2 repeats the rotation operation at the resonance frequency determined by the suspended portion including the second base 110-2 and the first torsion bars 120a-1 and 120b-1 within a predetermined angle range. May be. Specifically, the second base 110-2 includes a suspended portion including the second base 110-2 (in other words, the second base 110-2 suspended by the first torsion bars 120a-1 and 120b-1). Including the suspended portion) and the first torsion bars 120a-1 and 120b-1 may be rotated so as to resonate at a resonance frequency determined. For example, the moment of inertia about the axis along the X axis of the suspended portion including the second base 110-2 (more specifically, the second torsion bars 120a-2 to 120d provided in the second base 110-2) -2 and the second base 110-2 taking into account the mass of each of the

mirrors

130a and 130c, the suspended moment consisting of the entire system, ie, the moment of inertia about the axis along the X-axis) is I1 and the first torsion If the torsion spring constant when the bars 120a-1 and 120b-1 are regarded as one spring is k1, then the second base 110-2 is (1 / (2π)) × √ (k1 / I1 ) At the resonance frequency (or (1 / (2π)) × √ (k1 / I1) N times or 1 / N times (where N is an integer equal to or greater than 1)). In the direction of the X-axis Shaft may be rotated about axis was.

Furthermore, the electromagnetic force itself applied from the drive source unit 160 is different from the rotation direction of the

mirrors

130a and 130c (that is, the rotation direction centered on the direction along the Y axis). On the other hand, this electromagnetic force is transmitted to the second base 110-2 as fine vibration. More specifically, the drive source unit 160 is a fine vibration that propagates in the second base 110-2 while eliminating the twist in the rotational direction of the second base 110-2 itself with respect to the second base 110-2. Is added as wave energy. In other words, instead of applying a force that imparts a twist in the rotational direction to the second base 110-2 itself, the drive source unit 160 uses the inside of the second base 110-2 as energy (in other words, a wave that expresses the force). Adds a small vibration to propagate (as energy). Such fine vibration becomes a force having no directivity when propagating in the second base 110-2. In other words, the wave energy propagating in the second base 110-2 as a minute vibration propagates in the second base 110-2 in an arbitrary direction. Further, the second base 110-2 to which such a fine vibration is applied is a medium that propagates the fine vibration (in other words, wave energy) rather than the second base 110-2 itself becoming an oscillating object. Become.

As a result, the slight vibration applied from the drive source unit 160 to the second base 110-2 is transmitted from the second base 110-1 to the second torsion bars 120a-2 and 120b-2. After that, as shown in FIG. 11, the micro-vibration (in other words, wave energy) propagating through the second base 110-2 is directed in a direction corresponding to the elasticity of the second torsion bars 120a-2 and 120b-2 itself. The second torsion bars 120a-2 and 120b-2 are rotated toward the front, and the mirror 130a is rotated. In other words, the micro vibrations propagated in the second base 110-2 are manifested in the form of rotation of the second torsion bars 120a-2 and 120b-2 and rotation of the mirror 130a. In other words, this wave energy can be taken out as vibrations in all directions without limiting the direction of micro vibrations. That is, the wave energy propagated in the second base 110-2 can be extracted outside in the form of vibration (more specifically, resonance), and as a result, the mirror 130a can be rotated. As a result, as shown in FIG. 11, the mirror 130a rotates about the axis along the Y-axis direction as the central axis. More specifically, the mirror 130a repeats the rotation operation at the resonance frequency within a predetermined angle range (in other words, repeats the reciprocating motion of rotation within the predetermined angle range).

At this time, the mirror 130a rotates so as to resonate at a resonance frequency determined according to the mirror 130a and the second torsion bars 120a-2 and 120b-2. More specifically, the mirror 130a is a Y axis of the mirror 130a (more specifically, a suspended portion including the mirror 130a and a structure suspended by the second torsion bars 120a-2 and 120b-2). , And a torsion spring constant of the second torsion bars 120a-2 and 120b-2. For example, it is assumed that the moment of inertia about the axis along the Y axis of the mirror 130a is Ia and the torsion spring constant when the second torsion bars 120a-2 and 120b-2 are regarded as one spring is ka. For example, the mirror 130a has a resonance frequency specified by (1 / (2π)) × √ (ka / Ia) (or N times or N minutes of (1 / (2π)) × √ (ka / Ia). So that it resonates at a resonance frequency of 1 (where N is an integer equal to or greater than 1). For this reason, the drive source unit 160 applies slight vibration in a manner synchronized with the resonance frequency so that the mirror 130a resonates at the resonance frequency described above.

Strictly speaking, the resonance frequency of the mirror 130a may change depending on the rigidity and mass (or moment of inertia) of the base supporting the rotating system including the rotating body called the mirror 130a. For example, the resonance frequency of the mirror 130a is such that the rigidity and mass of the first base 110-1, the first torsion bars 120a-1 and 120b-1, the second base 110-2, and the like that support a rotating system including a rotating body called the mirror 130a. (Or moment of inertia). Therefore, in consideration of the rigidity and mass (or moment of inertia) of the base supporting the mirror 130a, an equation (1 / (2π)) × √ (ka / Ia) (or a parameter specifying the equation) A resonance frequency obtained as a result of performing a predetermined correction operation on certain ka and Ia) may be handled as the actual resonance frequency of the mirror 130a.

Similarly, the slight vibration applied from the drive source unit 160 to the second base 110-2 is transmitted from the second base 110-1 to the second torsion bars 120c-2 and 120d-2. After that, as shown in FIG. 11, the micro-vibration (in other words, wave energy) propagating in the second base 110-2 is directed in a direction corresponding to the elasticity of the second torsion bars 120c-2 and 120d-2 themselves. The second torsion bars 120c-2 and 120d-2 are rotated or the mirror 130c is rotated. In other words, the minute vibrations that have propagated through the second base 110-2 are manifested in the form of rotation of the second torsion bars 120c-2 and 120d-2 and rotation of the mirror 130c. In other words, this wave energy can be taken out as vibrations in all directions without limiting the direction of micro vibrations. That is, the wave energy propagated in the second base 110-2 can be extracted outside in the form of vibration (more specifically, resonance), and as a result, the mirror 130c can be rotated. As a result, as shown in FIG. 11, the mirror 130c rotates about the axis along the Y-axis direction as the central axis. More specifically, the mirror 130c repeats the rotation operation at the resonance frequency within a predetermined angle range (in other words, the reciprocating motion of rotation within the predetermined angle range is repeated).

At this time, the mirror 130c rotates so as to resonate at a resonance frequency determined according to the mirror 130c and the second torsion bars 120c-2 and 120d-2. More specifically, the mirror 130c is a Y-axis of the mirror 130c (more specifically, a suspended portion including the mirror 130c and suspended by the second torsion bars 120c-2 and 120d-2). , And the torsion spring constant of the second torsion bars 120c-2 and 120d-2. For example, it is assumed that the moment of inertia about the axis along the Y axis of the mirror 130c is Ic and the torsion spring constant when the second torsion bars 120c-2 and 120d-2 are regarded as one spring is kc. For example, the mirror 130a has a resonance frequency specified by (1 / (2π)) × √ (kc / Ic) (or N times or N minutes of (1 / (2π)) × √ (kc / Ic). So that it resonates at a resonance frequency of 1 (where N is an integer equal to or greater than 1). For this reason, the drive source unit 160 applies slight vibration in a manner synchronized with the resonance frequency so that the mirror 130c resonates at the resonance frequency described above.

Strictly speaking, the resonance frequency of the mirror 130a may change depending on the rigidity and mass (or moment of inertia) of the base supporting the rotating system including the rotating body called the mirror 130c. For example, the resonance frequency of the mirror 130a is such that the rigidity and mass of the first base 110-1, the first torsion bars 120a-1 and 120b-1, the second base 110-2, and the like that support a rotating system including a rotating body called the mirror 130c. (Or moment of inertia). Therefore, in consideration of the rigidity and mass (or moment of inertia) of the base supporting the mirror 130c, an equation (1 / (2π)) × √ (kc / Ic) (or a parameter for specifying the equation) A resonance frequency obtained as a result of performing a predetermined correction operation on a certain kc and Ic) may be handled as an actual resonance frequency of the mirror 130c.

In the fourth embodiment, it is preferable that the resonance frequency of the mirror 130a and the resonance frequency of the mirror 130c are the same. Specifically, it is preferable that (1 / (2π)) × √ (ka / Ia) = (1 / (2π)) × √ (kc / Ic). Alternatively, when the MEMS scanner 103 includes three or more mirrors 130, it is preferable that at least two of the plurality of mirrors 130 have the same resonance frequency.

Here, with reference to FIG. 12, the non-directional force caused by the fine vibration applied from the drive source unit 160 will be further described. Here, FIG. 12 is a plan view for explaining a force having no directivity due to the fine vibration applied from the drive source unit 160. In the following description, in order to make the description easy to understand, the description will be given using the drive source unit 160 having a configuration different from that of the drive source unit 160 shown in FIG. However, the electromagnetic force as fine vibration applied from the drive source unit 160 shown in FIG. 9 and the electromagnetic force as fine vibration applied from the drive source unit 160 shown in FIG. 12 are actually the same force (that is, direction). Power without sex).

As shown in FIG. 12, the drive source unit 160 includes a transmission branch 160b, a first support plate 160-1c connected to the first base 110-1 via the transmission branch 160b, and in the Y-axis direction. A first support plate 160-1c having first branches 160-1x and 160-1y facing each other along, and a second support plate 160-2c connected to the first base 110-1 via a transmission branch 160b. The second support plate 160-2c having the second branches 160-2x and 160-2y facing each other along the direction of the Y-axis and wound on the first branches 160-1x and 160-1y, respectively. A first coil 160-1z and a second coil 160-2z wound around each of the second branches 160-2x and 160-2y are provided. Further, it is assumed that the shapes and characteristics of the first branches 160-1x and 160-1y and the second branches 160-2x and 160-2y are the same, and the characteristics of the coil 160-1z wound around the first branch 160-1x ( For example, the number of turns, etc.) and the characteristics (eg, the number of turns, etc.) of the coil 160-1z wound around the first branch 160-1y are the same, and the coil 160-2z wound around the second branch 160-2x The characteristics (for example, the number of windings) and the characteristics (for example, the number of windings) of the coil 160-2z wound around the second branch 160-2y are the same.

Here, when an electric current is passed through the coils 160-1z and 160-2z wound around the first branches 160-1x and 160-1y and the second branches 160-2x and 160-2y, respectively, The force pulled in the direction of the first branch 160-1y and the second branch 160-2y with respect to the first branch 160-1x and the second branch 160-2x (that is, in the negative direction of the Y-axis, as shown in FIG. When a force acting in the direction toward the middle and lower side is generated, the first branch 160-1x and the second branch 160-2x are also applied to the first branch 160-1y and the second branch 160-2y. A force that is pulled in the direction (that is, a force acting in the positive direction of the Y axis and in the direction toward the upper side in FIG. 12) is generated. Since these forces are opposite to each other and have the same magnitude, the first branch 160-1x and the first branch 160-1y do not cause acceleration to the outside or generate acceleration themselves. Are joined at point P1 (in other words, point P1 on the transmission branch 160b) and point P2 (in other words, point P2 on the transmission branch 160b) where the second branch 160-2x and the second branch 160-2y are joined. Only fine vibrations are transmitted. As a result, the forces at points P1 and P2 are not directional. Similarly, the force that separates the first branch 160-1y and the second branch 160-2y from the first branch 160-1y and the second branch 160-2y by the electromagnetic interaction (that is, the positive direction of the Y-axis). When a force acting in the direction toward the upper side in FIG. 12 is generated, the first branch 160-1x and the second branch 160 are also applied to the first branch 160-1y and the second branch 160-2y. -2x is generated (that is, a force acting in the negative direction of the Y-axis and in the downward direction in FIG. 12). Since these forces are opposite to each other and have the same magnitude, the first branch 160-1x and the first branch 160-1y do not cause acceleration to the outside or generate acceleration themselves. Only a slight vibration is transmitted to the point P1 where the two parts are joined and the point P2 where the second branch 160-2x and the second branch 160-2y are joined. As a result, the forces at points P1 and P2 are not directional.

However, according to experiments by the inventors of the present application, the above-described configuration causes micro vibrations transmitted through the first base 110-1 and the first torsion bars 120a-1 and 120b-1 (that is, wave energy having directional characteristics). It has been found that the

mirrors

130a and 130c rotate about the axis along the direction of the Y axis as a central axis. That is, the micro-vibration applied by the drive source unit 160 propagates in the second base 110-2 as the above-described non-directional force (in other words, wave energy), so that the

mirrors

130a and 130c move in the Y-axis direction. It has been found that the axis along the axis rotates.

Thus, in the fourth embodiment, the axis along the Y-axis direction is centered so that the mirror 130a resonates at a resonance frequency determined according to the mirror 130a and the second torsion bars 120a-2 and 120b-2. The mirror 130a can be rotated as an axis. Furthermore, in the fourth embodiment, the axis along the Y-axis direction is set as the central axis so that the mirror 130c resonates at a resonance frequency determined according to the mirror 130c and the second torsion bars 120c-2 and 120d-2. The mirror 130c can be rotated. In addition, in the fourth embodiment, the second base 110-2 can be rotated about the axis along the X-axis direction as the central axis. Here, considering that the

mirrors

130a and 130c are connected to the second base 110-2 via the second torsion bars 120a-2 and 120b-2 and the second torsion bars 120c-2 and 120d-2. In accordance with the rotation of the second base 110-2 with the axis along the X-axis direction as the central axis, the

mirrors

130a and 130c also rotate about the axis along the X-axis direction as the central axis. As a result, the

mirrors

130a and 130c can be rotated so that the

mirrors

130a and 130c resonate with the X axis and the Y axis as the central axes. In other words, in the fourth embodiment, the

mirrors

130a and 130c are driven to rotate about the X axis as the central axis and self-resonate with the Y axis as the central axis.

mirrors

130a and 130c is reduced, the rotation range of the

mirrors

130a and 130c. Therefore, the

mirrors

130a and 130c can be moved more efficiently, and as a result, low power consumption of the MEMS scanner 103 can be realized.

In addition, in the fourth embodiment, a force having no directionality is applied.

Here, as a comparative example, a configuration in which a so-called directional force is applied to perform biaxial rotation driving of the

mirrors

130a and 130c (eg, the second base 110-2 itself is directed toward the rotation direction of the

mirrors

130a and 130c) Twisting the

mirrors

130a and 130c directly by directly twisting the torsion bars 120a-2 and 120b-2, the second torsion bars 120c-2 and 120d-2, and the

mirrors

130a and 130c. A configuration to be performed) will be described as an example. In this case, a force having directionality to rotate the

mirrors

130a and 130c about the axis along the X-axis direction (for example, the first base 110-1 is set about the axis along the X-axis direction as the central axis). A force (for example, the second base 110-) that applies a direction to rotate the

mirrors

130a and 130c about the axis along the direction of the Y axis as a central axis is applied from a certain drive source unit 160. 2 is required to be applied from the other drive source unit 160) (a force for twisting 2 to rotate about an axis along the Y-axis direction as a central axis). That is, when performing biaxial rotation driving of the

mirrors

130a and 130c by applying a force having directionality, normally, the MEMS scanner must include two or more drive source units 160. In other words, when the two-axis rotational drive of the

mirrors

130a and 130c is performed by applying a directional force, only one force acting in one direction can be applied from one drive source unit 160. The MEMS scanner must include two or more drive source units 160.

However, in the fourth embodiment, the two-axis rotation drive of the

mirrors

130a and 130c can be performed by applying a non-directional force due to the micro-vibration. Here, since a non-directional force due to the micro-vibration is applied, the micro-vibration (that is, non-directional force) applied from one drive source unit 160 is the first torsion bar 120a-1. 120b-1 (that is, the elasticity of rotating the second base 110-2 supporting the

mirrors

130a and 130c about the axis along the X-axis direction) and the second torsion bars 120a-2 to 120d- 2 using the elasticity of 2 (that is, the elasticity of rotating the

mirrors

130a and 130c about the axis along the Y-axis direction as the central axis), the

mirrors

130a and 130c are axes along the X-axis and Y-axis directions, respectively. Can be rotated around the center axis. That is, in the fourth embodiment, it is not always necessary to provide the two drive source units 160 even when the two-axis rotational drive of the

mirrors

130a and 130c is performed. For this reason, it is possible to apply a non-directional force due to the fine vibration for performing the biaxial rotation drive of the

mirrors

130a and 130c using the single drive source unit 160.

In addition, even if a force acting in two directions can be applied from one drive source unit, when the two-axis rotational drive of the

mirrors

130a and 130c is performed by applying a force having directionality, After all, a component acting in two directions (that is, a force component having a direction to rotate the

mirrors

130a and 130c about the axis along the X-axis direction as a central axis, and the

mirrors

130a and 130c as Y It is necessary to apply a force having a force component having a directionality that rotates the axis along the axis direction as a central axis. However, in the fourth embodiment, since a non-directional force due to micro vibration is applied as wave energy, there is an advantage that it is not necessary to apply the force in consideration of the direction in which the force acts. Yes.

In addition, since a non-directional force due to micro vibration is applied, the arrangement position of the drive source unit 160 is not limited. In other words, since a non-directional force due to micro vibration is applied, the arrangement position of the drive source unit 160 is not limited depending on the direction of rotation of the

mirrors

130a and 130c. In other words, no matter what the position of the drive source unit 160 is set, the minute vibration (that is, non-directional force) applied from the drive source unit 160 is caused by the second torsion bars 120a-2 and 120b. -2 and the elasticity of the second torsion bars 120c-2 and 120d-2, the

mirrors

130a and 130c can be rotated about the axis along the direction of the Y axis as the central axis. Thereby, the design freedom of the MEMS scanner 103 can be relatively increased. This is very advantageous in practice for MEMS scanners where the size or design constraints of each component are large.

Furthermore, in the fourth embodiment, since the rib 119 is formed on the back side of the second base 110-2, the second base 110-2 itself deforms and vibrates so as to wave due to the slight vibration applied from the drive source unit 160. . Hereinafter, the deformation vibration mode of the second base 110-2 will be described with reference to FIG. FIG. 13 is a side view showing the deformation vibration mode of the second base 110-2 in association with the rotation mode of the mirrors 130a and 130b. FIG. 13 is a side view when the second base 110-2 and the

mirrors

130a and 130c are observed from the direction of the arrow “X” shown in FIG.

As shown in FIG. 13 (a), in the state where the micro-vibration is not applied from the drive source unit 160 to the second base 110-2, the second base 110-2 is not deformed and the mirror 130a. And 130b are not rotated.

As shown in FIG. 13B, when a slight vibration is applied from the drive source unit 160 to the second base 110-2, the region 110a where the rib 119 is formed has a relatively high rigidity. While it is difficult to bend due to slight vibration, the region 110b where the rib 119 is not formed is relatively low in rigidity, and thus is easily bent due to slight vibration. As a result, the second base 110-2 deforms and vibrates so as to wave in the direction of the X axis, with the region 110a where the rib is formed as a node and the region 110b where the rib 119 is not formed as a belly. . More specifically, the second base 110-2 vibrates while deforming its appearance like a standing wave having a portion where the rib 119 is formed as a node and a portion where the rib 119 is not formed as a belly. . In the example shown in FIG. 13B, the second base 110-2 is deformed and oscillated so as to be bent from the center thereof. However, the second base 110-2 may be subjected to deformation vibration in another deformation mode (for example, a deformation mode having more nodes).

In addition, the deformation vibration of the second base 110-2 in the fourth embodiment is realized by forming the rib 119 at an appropriate location. Therefore, in the rib 119 described above, the second base 110-2 deforms and vibrates along the X-axis direction with the region 110a where the rib is formed as a node and the region 110b where the rib 119 is not formed as an antinode. Thus, it is preferably formed at an appropriate location on the second base 110-2. At this time, it is preferable that the portion where the second torsion bars 120a-2 and 120b-2 and the second torsion bars 120c-2 and 120d-2 are connected corresponds to the region 110a. For example, in the rib 119 described above, a portion having a relatively high bending rigidity along the X-axis direction and a portion having a relatively low bending rigidity along the X-axis direction appear in order along the X-axis direction. Thus, it is preferably formed at an appropriate location on the second base 110-2. Alternatively, for example, in the rib 119 described above, a portion having a relatively high bending rigidity along the X-axis direction and a portion having a relatively low bending rigidity along the X-axis direction are along the X-axis direction. As shown in order, the portion to which the second torsion bars 120a-2 and 120b-2 and the second torsion bars 120c-2 and 120d-2 are connected becomes the region 110a, and the other portions become the region 110b. Preferably, the second base 110-2 is formed at an appropriate location.

At this time, depending on the period of fine vibration applied from the drive source unit 160, the second base 110-2 undergoes deformation vibration so as to resonate. Here, in the fourth embodiment, the resonance frequency in the deformation vibration of the second base 110-2 is preferably the same as the resonance frequency of the mirrors 130a and 130b. In other words, it is preferable that the characteristics of the second base 110-2 be determined such that the second base 110-2 deforms and vibrates at the same resonance frequency as that of the mirrors 130a and 130b. For example, the characteristics of the ribs 119 formed on the back side of the second base 110-2 so as to deform and vibrate at the same resonance frequency as that of the mirrors 130a and 130b (for example, the formation position, size, mass, (Rigidity, density, etc.) are preferably determined.

The resonance frequency in the deformation vibration of the second base 110-2 is that the structure including the second base 110-2 and the rib 119 is regarded as one spring system, and the mass added to the spring system is M and When the spring constant of the spring system is k, it is specified by (1 / (2π)) × √ (k / M). However, if the spring system is a one-degree-of-freedom spring system in which one mass structure is connected to one spring (in other words, the natural frequency is one and the natural vibration mode is one). , (1 / (2π)) × √ (k / M) resonant frequency can be employed. On the other hand, if the spring system is a spring system having two or more degrees of freedom in which two mass structures are connected to one spring, the resonance frequency “1 / (2π)) × √ (k / M)” It is preferable to correct “k” and “M”. When the structure including the second base 110-2 and the rib 119 is regarded as one spring system, the mass M added to the spring system and the spring constant k of the spring system are determined by the second base 110-. 2 is determined according to rigidity and mass. In the fourth embodiment, the rigidity and mass of the second base 110-2 are adjusted by the rib 119. Therefore, the resonance frequency of the second base 110-2 is substantially determined by the characteristics of the rib 119 described above.

Strictly speaking, the resonance frequency in the deformation vibration of the second base 110-2 varies depending on the rigidity and mass (or moment of inertia) of the base supporting the vibration system including the deformation vibration body called the second base 110-2. There is no doubt. For example, the resonance frequency in the deformation vibration of the second base 110-2 is such that the first base 110-1 and the first torsion bars 120a-1 and 120b-1 supporting the vibration system including the deformation vibration body called the second base 110-2. It may change depending on rigidity and mass (or moment of inertia). Therefore, in consideration of the rigidity and mass (or moment of inertia) of the base supporting the second base 110-2, an equation (1 / (2π)) × √ (k / M) (or the equation) The resonance frequency obtained as a result of performing a predetermined correction operation on the specified parameters k and M) may be handled as the resonance frequency in the actual deformation vibration of the second base 110-2.

The resonance in the deformation vibration of the second base 110-2 regards the spring system related to the deformation vibration of the second base 110-2 as a two-degree-of-freedom spring system in which two mass structures are connected to one spring. Instead of the above, it may be defined as a higher-order resonance mode of a plate-like member called the second base 110-2.

mirrors

130a and 130c resonate at the resonance frequency. Accordingly, the second base 110-2 is deformed and oscillated so as to resonate due to the application of such fine vibration. That is, as shown in FIG. 13A to FIG. 13F in time series, the second base 110-2 deforms and vibrates so as to have an appearance like a standing wave with both ends open. That is, the second base 110-2 has an appearance such that a standing wave appears along a direction orthogonal to the rotation axes of the

mirrors

130a and 130c (that is, the X-axis direction).

When the second base 110-2 deforms and vibrates in this manner, the second base 110-2 on the mirror 130a side (specifically, the relatively left side of each of FIGS. 13 (a) to 13 (f)). Of the second base 110-2) and the second base 110-2 on the side of the mirror 130c (specifically, the second base on the relatively right side of each of FIGS. 13 (a) to 13 (f)). This is the opposite of the deformation mode of the base 110-2). For example, when the second base 110-2 on the mirror 130a side is deformed counterclockwise around the rotation axis of the mirror 130a (for example, as illustrated in FIGS. 13A to 13C). The second base 110-2 on the mirror 130c side is deformed clockwise around the rotation axis of the mirror 130c. Similarly, for example, when the second base 110-2 on the mirror 130a side is deformed clockwise around the rotation axis of the mirror 130a (for example, as shown in FIGS. 13 (d) to 13 (f)). When deformed), the second base 110-2 on the mirror 130c side is deformed counterclockwise around the rotation axis of the mirror 130c. Accordingly, since the resonance frequencies of the

mirrors

130a and 130c are the same, the

mirrors

130a and 130c have a rotation phase of the mirror 130a and a rotation phase of the mirror 130c in accordance with the deformation vibration of the second base 110-2. Rotate so that they are out of phase with each other. In other words, the

mirrors

130a and 130c rotate so that the deviation between the rotation phase of the mirror 130a and the rotation phase of the mirror 130c is fixed at 180 °. The relationship between the phase of rotation of the mirror 130a and the phase of rotation of the mirror 130c is based on which deformation vibration of the second base 110-2 occurs as shown in FIGS. 13 (c) to 13 (f). This is true even in such a state.

Note that the deviation between the phase of rotation of the mirror 130a and the phase of deformation vibration of the second base 110-2 may vary over time or may be fixed. Similarly, the deviation between the phase of rotation of the mirror 130c and the phase of deformation vibration of the second base 110-2 may vary with time or may be fixed. The above description using FIG. 13 shows an example in the case where the deviation between the rotation phase of the

mirrors

130a and 130c and the phase of the deformation vibration of the second base 110-2 is fixed. However, even if the deviation between the phase of the rotation of the

mirrors

130a and 130c and the phase of the deformation vibration of the second base 110-2 varies, the

mirrors

130a and 130c There is no change in the rotation so that the phases of the rotation of 130c are opposite to each other.

Thus, according to the fourth embodiment, the

mirrors

130a and 130c is lowered, the driving frequency of the mirror 130 when the

mirrors

130a and 130c are handled like one mirror 130 is not lowered.

FIG. 13 shows an example in which the rotation phase of each of the

mirrors

130a and 130c and the phase of the deformation vibration of the second base 110-2 are reversed. However, as shown in FIG. 14, the rotation phase of each of the

mirrors

130a and 130c may be in phase with the phase of the deformation vibration of the second base 110-2. Even if the phase of rotation of each of the

mirrors

130a and 130c and the phase of the deformation vibration of the second base 110-2 are in phase, the phase of the deformation vibration of the base 110 may be in phase. Various effects that can be enjoyed when the phase of the rotation of each of the

mirrors

130a and 130c and the phase of the deformation vibration of the second base 110-2 are reversed are preferably enjoyed.

In addition, in the fourth embodiment, the magnetic pole 162a is a side 110-2 on one side of the second base 110-2 and a region between the mirror 130a and the mirror 130c (that is, the second base 110-2). The

magnetic poles

162b and 162c are located on the side opposite to the magnetic pole 162a with respect to the rotation axis of the second base 110-2. In addition, the mirror 130a and the mirror 130c are disposed at positions where the mirror 130a and the mirror 130c are sandwiched along the Y-axis direction. That is, the magnetic pole 162a is disposed at a position where the rotation axis of the second base 110-2 is sandwiched between the

magnetic poles

162b and 162c. This makes it easier to rotate the second base 110-2 along the X-axis direction. Further, the

magnetic poles

162b and 162c are arranged at positions where the second base 110-2 (or the mirror 130a and the mirror 130c) is sandwiched along the direction of the Y axis. Accordingly, the second base 110-2 is easily deformed and vibrated by the slight vibration generated by the

magnetic poles

162b and 162c.

In the fourth embodiment described above, an example is described in which fine vibration is used as the force for rotating the

mirrors

130a and 130c may be used. In other words, for example, the first torsion bars 120a-1 and 120b-1 and the second torsion bars 120a-1 to 120d-1 act as a force for rotating the

mirrors

130a and 130c in the direction of directly twisting. A directional force may be used. The same applies to the following fifth to sixth embodiments.

(5) Fifth Embodiment Next, the MEMS scanner 104 of the fifth embodiment will be described with reference to FIG. FIG. 15 is a plan view conceptually showing the basic structure of the MEMS scanner 104 of the fifth embodiment. In addition, about the same structure as the MEMS scanner 103 of the above-mentioned 4th Example, the detailed description is abbreviate | omitted by attaching | subjecting the same referential mark.

As shown in FIG. 15, the MEMS scanner 104 according to the fifth embodiment is similar to the MEMS scanner 103 according to the fourth embodiment in that the first base 110-1, the first torsion bars 120a-1 and 120b-1, A second base 110-2, second torsion bars 120a-2 and 120b-2, second torsion bars 120c-2 and 120d-2, a mirror 130a, and a mirror 130c are provided. The MEMS scanner 104 of the fifth embodiment includes a drive source unit 140 that applies a force (microvibration) due to the piezoelectric effect, instead of the drive source unit 160 that applies a force (microvibration) due to electromagnetic force. .

The drive source unit 140 includes a first piezoelectric element 140-1a, a second piezoelectric element 140-2a, a transmission branch 140b, a first gap 140-1d, and the first base 110-1 via the transmission branch 140b. And a second support plate 140-2c having a second gap 140-2d and fixed to the first base 110-1 via the transmission branch 140b. . On the first support plate 140-1c, the first piezoelectric element 140-1a is sandwiched by the first branches 140-1e and 140-1f facing each other defined by the first gap 140-1d. On the second support plate 140-2c, the second piezoelectric element 140-2a is sandwiched between the opposing second branches 140-2e and 140-2f defined by the second gap 140-2d. By applying a voltage to the first piezoelectric element 140-1a via an electrode (not shown), the first piezoelectric element 140-1a changes its shape. This change in the shape of the first piezoelectric element 140-1a causes a change in the shape of the first branches 140-1e and 140-1f. As a result, changes in the shapes of the first branches 140-1e and 140-1f are transmitted to the first base 110-1 via the transmission branch 140b as fine vibration (or wave energy) as will be described in detail later. Similarly, by applying a voltage to the second piezoelectric element 140-2a via an electrode (not shown), the second piezoelectric element 140-2a changes its shape. This change in the shape of the second piezoelectric element 140-2a causes a change in the shape of the second branches 140-2e and 140-2f. As a result, changes in the shapes of the second branches 140-2e and 140-2f are transmitted to the first base 110-1 via the transmission branch 140b as fine vibration (or wave energy) as will be described in detail later.

Such micro-vibration applied from the drive source unit 140 is a force having no direction described with reference to FIG. Therefore, according to the MEMS scanner 104 of 5th Example, the effect similar to the various effects which the MEMS scanner 103 of 4th Example mentioned above can enjoy can be enjoyed suitably.

(6) Sixth Embodiment Next, the MEMS scanner 105 of the sixth embodiment will be described with reference to FIG. FIG. 16 is a plan view conceptually showing the basic structure of the MEMS scanner 105 of the sixth embodiment. In addition, about the same structure as the MEMS scanner 103 of the above-mentioned 4th Example, the detailed description is abbreviate | omitted by attaching | subjecting the same referential mark.

As shown in FIG. 16, the MEMS scanner 105 of the sixth embodiment is similar to the MEMS scanner 103 of the fourth embodiment in that the first base 110-1, the first torsion bars 120a-1 and 120b-1, A second base 110-2, second torsion bars 120a-2 and 120b-2, second torsion bars 120c-2 and 120d-2, a mirror 130a, and a mirror 130c are provided. The MEMS scanner 105 according to the sixth embodiment includes a drive source unit 150 that applies a force (microvibration) due to an electrostatic force, instead of the drive source unit 160 that applies a force (microvibration) due to electromagnetic force. .

The drive source unit 150 (150a to 150c) is provided on the inner side of the first base 110-1 and the comb-shaped first electrodes 151a to 151c arranged along the outer side of the second base 110-2. Comb-like second electrodes 152a to 152c that are fixed and distributed between the first electrodes 151a to 151c are provided. The first electrode 151a and the second electrode 152a are arranged at the same position as the magnetic pole 162a described above. The first electrode 151b and the second electrode 152b are disposed at the same position as the magnetic pole 162b described above. The first electrode 151c and the second electrode 152c are disposed at the same position as the magnetic pole 162c described above.

In this case, a desired voltage is applied to the first electrodes 151a to 151c (or the second electrodes 152a to 152c) at a desired timing from a drive source unit control circuit (not shown). Due to the potential difference between the first electrode and the second electrode, an electrostatic force (in other words, Coulomb force) is generated between the first electrodes 151a to 151c and the second electrodes 152a to 152c. As a result, electrostatic force is generated. This electrostatic force is transmitted to the second base 110-2 as a slight vibration.

Such micro-vibration applied from the driving source unit 150 is a force having no direction described with reference to FIG. Therefore, according to the MEMS scanner 105 of the sixth embodiment, it is possible to preferably enjoy the same effects as the various effects that the MEMS scanner 103 of the fourth embodiment described above enjoys.

In the above description, the MEMS scanners 100 to 106 including two

mirrors

130a and 130c are described. However, the above-described configuration may be applied to a MEMS scanner including three or more mirrors 130. Needless to say.

Note that the MEMS scanner 100 of the first embodiment to the MEMS scanner 105 of the sixth embodiment described above are various types such as a head-up display, a head mounted display, a laser scanner, a laser printer, and a scanning drive device. It can be applied to electronic 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 to 105 MEMS scanner 110 base 110-1 first base 110-2 second base 120 torsion bar 120-1 first torsion bar 120-2 second torsion bar 130

mirror

140, 150, 160 drive source section

Claims

A base part;
A plurality of driven parts each rotatable,
Each connects the base part and a corresponding one of the plurality of driven parts, and each of the corresponding driven parts has an axis along one direction as a central axis. A plurality of elastic parts having elasticity to rotate;
Each of the driven parts has an axis along the one direction at a resonance frequency determined by one of the plurality of driven parts and one elastic part corresponding to each of the driven parts among the plurality of elastic parts. An application unit that applies an excitation force to the base unit to rotate the plurality of driven units so as to rotate while resonating as a central axis;
The application unit has a phase in which a first driven unit among the plurality of driven units rotates is opposite to a phase in which a second driven unit among the plurality of driven units rotates. As described above, the driving force is applied.
The resonance frequency determined by each of the plurality of driven parts and one elastic part corresponding to each of the driven parts among the plurality of elastic parts is the same between at least two of the plurality of driven parts. The drive device according to claim 1, wherein
The application unit applies the excitation force so that the base unit deforms and vibrates in a standing wave shape along another direction different from the one direction,
2. The driving device according to claim 1, wherein each of the plurality of driven parts is connected to a portion corresponding to a node in the deformation vibration of the base part via the plurality of elastic parts.
4. The driving apparatus according to claim 3, wherein the application unit applies the excitation force so that the deformation vibration of the base unit along the other direction becomes resonance.
5. The driving device according to claim 4, wherein a resonance frequency at which the base portion resonates is the same as at least one resonance frequency of the plurality of driven portions.
4. The drive device according to claim 3, wherein the rigidity of the portion corresponding to the node in the deformation vibration of the base portion is higher than the rigidity of the portion other than the node in the deformation vibration of the base portion.
The drive device according to claim 3, wherein a mass of a portion corresponding to a node in the deformation vibration of the base portion is smaller than a mass of a portion other than the node in the deformation vibration of the base portion.
The driving device according to claim 1, wherein the excitation force is non-directional fine vibration or anisotropic fine vibration as non-directional vibration energy.
The driving device according to claim 8, wherein the application unit applies the micro vibration generated by a force acting in a direction different from a rotation direction having an axis along the one direction as a central axis.
9. The driving apparatus according to claim 8, wherein the application unit applies the micro vibration generated by a force acting in a direction along the surface of the driven unit when stationary.