JP2012022321A - Driving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a driving device for moving a stage by using the force except for directional force.SOLUTION: A driving device 100 comprises; a base part 110; a rotatable driven part 130; an elastic part 120 which connects the base part 110 and the driven part 130 and which has elasticity to rotate the driven part 130 around an axis along one direction; and an application part 140 for applying minute vibration to the base part to rotate the driven part 130 around the axis along one direction (Y-axis) with resonating at a resonant frequency determined by the driven part 130 and the elastic part 120.

Description

  The present invention relates to a technical field of a drive 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 a MEMS (Micro Electro Mechanical System) device manufactured by a semiconductor process technology is actively advanced. 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

  In a mirror driving device having such a configuration, a configuration in which a mirror is driven using a coil and a magnet is generally used. In such a configuration, for example, a configuration in which a coil is directly attached to a mirror can be given as an example. In this case, a force in the rotational direction is applied to the mirror by the interaction between the magnetic field generated by passing a current through the coil and the magnetic field of the magnet, and as a result, the mirror is rotated. In Patent Document 1 described above, a configuration is adopted in which the coil and the magnet are arranged so as to cause distortion in the twisting direction (in other words, the rotation axis direction of the mirror) of the torsion bar. In this case, the torsion bar is distorted in the twisting direction due to the interaction between the magnetic field generated by passing a current through the coil and the magnetic field of the magnet, and the distortion in the twisting direction of the torsion bar rotates the mirror.

  With respect to such a conventional mirror driving device, the present invention is, for example, a force other than a force that directly causes mirror rotation or a force that directly causes distortion in the torsional direction of the torsion bar (that is, in the rotation direction of the mirror). It is an object of the present invention to provide a driving device (that is, a MEMS scanner) that can drive a mirror (or a rotating driven object) by the action of a force other than the acting force.

  In order to solve the above-described problem, a driving device connects a base portion, a rotatable driven portion, the base portion and the driven portion, and the driven portion is an axis along one direction. And an elastic portion having elasticity such that the driven portion rotates about the axis along the one direction as a central axis at a resonance frequency determined by the driven portion and the elastic portion. And an application unit for applying a fine vibration for rotating the driven unit to the base unit.

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

It is a top view which shows notionally the structure of the drive device which concerns on 1st Example. It is a top view which shows notionally the aspect of the operation | movement by the drive device which concerns on 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 top view which shows notionally the structure of the drive device which concerns on 2nd Example. It is a top view which shows notionally the aspect of the operation | movement by the drive device which concerns on 2nd 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 graph of an experimental result. It is a top view which shows notionally one example of a structure of the drive device which concerns on 3rd Example. It is a top view which shows notionally the other example of a structure of the drive device which concerns on 3rd Example. It is a top view which shows notionally the structure of the drive device which concerns on 4th Example. It is a top view which shows notionally other structures of the drive device which concerns on 4th Example.

  Hereinafter, as the best mode for carrying out the invention, embodiments according to a driving device will be described in order.

  The drive device according to the present embodiment connects a base portion, a rotatable driven portion, the base portion and the driven portion, and the driven portion has an axis along one direction as a central axis. An elastic portion having elasticity to rotate, and the driven portion so that the driven portion rotates at a resonance frequency determined by the driven portion and the elastic portion while resonating with an axis along the one direction as a central axis. And an application unit that applies micro vibrations for rotating the drive unit to the base unit.

  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.

  In the driving device of the present embodiment, in particular, the fine vibration that the driven unit rotates while resonating around the axis along one direction at the resonance frequency determined by the driven unit and the elastic unit by the operation of the applying unit. Is added. At this time, the application unit according to the present embodiment applies micro vibrations to the base unit so that the micro vibrations propagate through the structure called the base unit. That is, the application unit according to the present embodiment, instead of applying a force that directly twists the base unit itself, the fine vibration propagating in the structure is subjected to excitation energy for rotating the driven unit (in other words, Wave energy). In other words, the application unit according to the present embodiment generates micro vibrations that propagate in the structure as energy (in other words, energy that expresses the force without changing the force of “vibration” into vibration). Is added as wave energy to rotate 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 the elastic portion (further, from the base portion to the driven portion via the elastic portion). After that, micro vibrations (in other words, wave energy) propagating through the structure cause the elastic part to vibrate in a direction corresponding to the elasticity of the elastic part itself, or to be applied in a direction corresponding to the elasticity of the elastic part. Rotate the drive. 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 extracted outside in the form of vibration (more specifically, resonance), and as a result, the driven portion 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 the driven part is rotationally driven by applying a so-called directional force (for example, the base part itself is largely twisted in the rotational direction of the driven part, and the twist is applied to the elastic part or the driven part. Force to rotate the driven part about the axis along one direction as a central axis (that is, a structure such as a base part) It is necessary to apply from the application unit a force having a directivity that twists in the direction of rotation about the axis along one direction as the central axis. 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 the present 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 driven unit. In other words, no matter what the position of the application unit is set, the micro-vibration (i.e., non-directional force) applied from the application unit uses the elasticity of the elastic unit to drive the driven unit. An axis along one direction can be rotated as a central axis. Thereby, the freedom degree of design of a drive device can be increased relatively.

  In one aspect of the drive device of the present embodiment, the micro vibration is non-directional micro vibration or anisotropic micro vibration as non-directional vibration energy.

  According to this aspect, 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. 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 extracted outside in the form of vibration (more specifically, resonance), and as a result, the driven portion can be rotated.

  In another aspect of the driving apparatus of the present embodiment, the application unit applies the fine vibration generated by a force acting in a direction different from a rotation direction with the axis along the one direction as a central axis.

  According to this aspect, when applying the minute vibration, the application unit first acts in 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 the power to do. 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 having an axis along one direction as a central axis. . Therefore, the various effects described above can be suitably enjoyed.

  In another aspect of the driving apparatus of the present embodiment, the application unit applies the minute vibration generated by a force acting in a direction along the surface of the driven unit when stationary.

  According to this aspect, when applying the fine vibration, the application unit first acts in a direction along the surface of the driven unit at rest (in other words, at the initial placement) (that is, in-plane direction). Generate the power to do. 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 surface of the driven part at rest. Therefore, the various effects described above can be suitably enjoyed.

  In another aspect of the driving apparatus of the present embodiment, the elastic portion has elasticity such that the driven portion rotates about an axis along another direction different from the one direction as a central axis. The application unit rotates the driven unit so that the driven unit rotates at a resonance frequency determined by the driven unit and the elastic unit while resonating with the axis along the one direction as a central axis. Therefore, the driven part is rotated such that the driven part resonates with the axis along the other direction as a central axis at a resonance frequency determined by the suspended part including the driven part and the elastic part. The fine vibration for rotating the part is applied to the base part.

  According to this aspect, the driven part is elastic 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, and the driven part in the other direction. The elasticity of being able to rotate around the axis along the center axis) is driven to rotate about the axis along one direction as the center axis and about the axis along the other direction as the center axis. That is, the drive device according to this aspect can perform the biaxial rotation drive of the driven part. However, it goes without saying that multi-axis rotational drive of two or more axes may be performed.

  In this aspect, in particular, a suspended portion including a driven portion (more specifically, a suspended portion made of a structure that suspends the driven portion, and a driven portion that will be described in detail later, by the operation of the applying portion. And a suspended portion made of a structure composed of a second base portion and a second elastic portion) and an elastic portion (more specifically, a first elastic portion that suspends the second base portion described in detail later). A slight vibration is applied such that the driven part (in other words, the suspended part including the driven part) rotates at the resonance frequency while resonating with the axis along the other direction as the central axis. More specifically, a suspended portion including a driven portion (more specifically, a suspended portion made of a structure that suspends the driven portion, driven by the operation of the applying portion, which will be described in detail later. Moment of inertia about the axis along the other direction and the elastic part (more specifically, the first to be described in detail later), and the second base part and the second elastic part. Slight vibration such that the driven part (in other words, the suspended part including the driven part) rotates while resonating around the axis along the other direction at the resonance frequency determined by the torsion spring constant of one elastic part) Is added. At the same time, this slight vibration causes the driven part to move in one direction at a resonance frequency determined by the driven part and the elastic part (more specifically, a second elastic part that suspends the driven part, which will be described in detail later). Rotate while resonating around the axis along the axis. More specifically, this slight vibration is caused by the moment of inertia around the axis along one direction of the driven part and the torsion spring constant of the elastic part (more specifically, the second elastic part described in detail later). The driven part is rotated while resonating with the axis along one direction as the central axis at a fixed resonance frequency. That is, in this aspect, a minute vibration for performing the biaxial rotation drive of the driven part is applied from the same application part (in other words, a single application part).

  Here, in the case of performing biaxial rotation driving of the driven part by applying a so-called directional force (for example, the base part itself is largely twisted in the rotational direction of the driven part, and the torsion is In the case where the driven part is driven biaxially by being directly applied to the driven part), a force having a directionality that rotates the driven part around the axis along one direction (that is, the base part) A force having a directionality that twists a structure body such as a direction of rotation about an axis along one direction as a central axis) from one application unit, and a driven unit along an axis along the other direction. Other force that has the directionality to rotate around the center axis (that is, the force that has the directionality to twist the structure such as the base portion in the rotation direction about the axis along the other direction as the central axis) It is necessary to add from the department. In other words, in the case where the driven part is driven by biaxial rotation by applying a directional force, the drive device usually includes two or more application parts (that is, two or more drive sources). Must be. In other words, when the driven part is biaxially rotated by applying a directional force, only one force acting in one direction can be applied from one application part. The driving device must include the above-described application unit (that is, two or more driving sources).

  However, in this aspect, it is possible to perform the biaxial rotation drive of the driven part by applying a non-directional force due to the minute vibration. Here, since a non-directional force due to the micro vibration is applied, the micro vibration applied from one application unit is caused by the elasticity of the elastic unit (that is, the axis of the driven unit along one direction). And rotating the driven part about the axis along one direction as the central axis, using the elasticity of rotating the driven part as the central axis and the elasticity of rotating the driven part about the axis along the other direction as the central axis. The driven part can be rotated about the axis along the other direction as the central axis. That is, in this aspect, even when the driven part is driven in a biaxial rotation, it is not always necessary to provide two application parts. For this reason, the fine vibration for performing the biaxial rotation drive of the driven part can be applied using a single application part (in other words, a single drive source).

  In addition, even if a force acting in two directions can be applied from one application unit, when performing a biaxial rotation drive of the driven unit by applying a force having directionality, After all, components acting in two directions (that is, a force component having a directionality that rotates the driven portion around the axis along one direction as a central axis, and the driven portion along the other direction) It is necessary to apply a force having a direction component that rotates the axis about the axis. However, in this aspect, since a non-directional force due to micro vibration is applied as excitation energy, there is an advantage that it is not necessary to apply the force after considering the direction in which the force acts. .

  In another aspect of the drive device of the present embodiment, the base portion includes a first base portion and a second base portion that is at least partially surrounded by the first base, and the elastic portion includes (i) (Ii) a first elastic portion having elasticity that connects the first base portion and the second base portion and rotates the second base portion around an axis along the other direction as a central axis; A second elastic part that connects the second base part and the driven part and has elasticity such that the driven part is rotated about an axis along the one direction as a central axis; Rotates the second base portion so that the second base portion rotates at a resonance frequency determined by the second base portion and the first elastic portion while resonating with the axis along the other direction as a central axis. The micro-vibration and the driven part and The fine vibration for rotating the driven part is applied so that the driven part rotates at a resonance frequency determined by the second elastic part while resonating with an axis along the one direction as a central axis.

  According to this aspect, the driven part is elastic 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, and the driven part in the other direction. The elasticity of being able to rotate around the axis along the center axis) is driven to rotate about the axis along one direction as the center axis and about the axis along the other direction as the center axis. More specifically, the second base portion is rotated about the axis along the other direction as a central axis by utilizing the elasticity of the first elastic portion, and the driven portion is utilized by utilizing the elasticity of the second elastic portion. An axis along one direction can be rotated as a central axis. Here, since the driven portion is connected to the second base portion via the second elastic portion, the second base portion rotates about the axis along the other direction as a central axis, and as a result, the driven portion The drive unit also rotates about the axis along the other direction as the central axis. That is, the drive device according to this aspect can perform the biaxial rotation drive of the driven part. However, it goes without saying that multi-axis rotational drive of two or more axes may be performed.

  In this aspect, in particular, the second base portion (in other words, the driven portion supported by the second base portion) at a resonance frequency determined by the suspended portion including the second base portion and the first elastic portion by the operation of the application portion. A micro-vibration is applied that rotates while resonating with the axis along the other direction as the central axis. More specifically, the suspended portion including the second base portion (more specifically, the suspended portion including the second base portion that suspends the driven portion by the operation of the application unit. , A driven part, and a suspended part made of a structure composed of a second base part and a second elastic part) resonance determined by the moment of inertia around the axis along the other direction and the torsion spring constant of the first elastic part A minute vibration is applied such that the second base portion (in other words, the driven portion supported by the second base portion) rotates at a frequency while resonating with an axis along another direction as a central axis. At the same time, this micro vibration rotates the driven part while resonating with the axis along one direction as the central axis at a resonance frequency determined by the driven part and the second elastic part. More specifically, this micro vibration causes the driven part to move in one direction at a resonance frequency determined by the moment of inertia about the axis along one direction of the driven part and the torsion spring constant of the second elastic part. Rotate while resonating around the axis along the axis. That is, in this aspect, a minute vibration for performing the biaxial rotation drive of the driven part is applied from the same application part (in other words, a single application part).

  Here, in the case of performing biaxial rotation driving of the driven part by applying a so-called directional force (for example, the base part itself is largely twisted in the rotational direction of the driven part, and the torsion is In the case where the driven part is driven biaxially by being directly applied to the driven part), a force having a directionality that rotates the driven part around the axis along one direction (that is, the base part) A force having a directionality that twists a structure body such as a direction of rotation about an axis along one direction as a central axis) from one application unit, and a driven unit along an axis along the other direction. Other force that has the directionality to rotate around the center axis (that is, the force that has the directionality to twist the structure such as the base portion in the rotation direction about the axis along the other direction as the central axis) It is necessary to add from the department. In other words, in the case where the driven part is driven by biaxial rotation by applying a directional force, the drive device usually includes two or more application parts (that is, two or more drive sources). Must be. In other words, when the driven part is biaxially rotated by applying a directional force, only one force acting in one direction can be applied from one application part. The driving device must include the above-described application unit (that is, two or more driving sources).

  However, in this aspect, it is possible to perform the biaxial rotation drive of the driven part by applying a non-directional force due to the minute vibration. Here, since a non-directional force due to the fine vibration is applied, the fine vibration applied from one application unit causes the elasticity of the first and second elastic portions (that is, the driven portion is controlled by one). The elasticity of rotating the axis along the direction as the central axis and the elasticity of rotating the driven part around the axis along the other direction). While rotating as an axis | shaft, a to-be-driven part can be rotated centering on the axis | shaft along another direction. That is, in this aspect, even when the driven part is driven in a biaxial rotation, it is not always necessary to provide two application parts. For this reason, the fine vibration for performing the biaxial rotation drive of the driven part can be applied using a single application part (in other words, a single drive source).

  In addition, even if a force acting in two directions can be applied from one application unit, when performing a biaxial rotation drive of the driven unit by applying a force having directionality, After all, components acting in two directions (that is, a force component having a directionality that rotates the driven portion around the axis along one direction as a central axis, and the driven portion along the other direction) It is necessary to apply a force having a direction component that rotates the axis about the axis. However, in this aspect, since a non-directional force due to micro vibration is applied as excitation energy, there is an advantage that it is not necessary to apply the force after considering the direction in which the force acts. .

  In the above description, the suspended portion including the second base portion is described as an example of a suspended portion including a driven body and a structure composed of the second base portion and the second elastic portion. . However, when other structures (for example, magnetic poles, coils, or comb-like electrodes described later) are installed on the second base portion, these other structures also form the suspended portion. It will be.

  In this aspect, the application unit rotates at a resonance frequency determined by the second base unit and the first elastic unit while resonating with the axis along the other direction as a central axis. The fine vibration for rotating the second base portion, and the driven portion resonates with an axis along the one direction as a central axis at a resonance frequency determined by the driven portion and the second elastic portion. The fine vibration for rotating the driven part so as to rotate may be applied to the first base part.

  If comprised in this way, the biaxial rotation drive of a to-be-driven part can be performed suitably by applying a slight vibration to a 1st base part.

  In another aspect of the driving apparatus of the present embodiment, the driven part is divided into a plurality of driven parts, and the elastic part is (i) a first group of the plurality of driven parts. The driven part is connected to the base part and the driven part of the first group is rotated about an axis along at least one of the one direction and another direction different from the one direction as a central axis. And (ii) connecting a second group of driven parts different from the first group of driven parts among the plurality of driven parts and the base part, and A fourth elastic portion having elasticity that rotates the driven portion of the second group around an axis along at least one of the one direction and the other direction as a central axis, and the application portion includes the first portion The resonance frequency determined by a group of driven parts and the third elastic part The fine for rotating the driven portion of the first group so that the driven portion of the first group rotates while resonating with an axis along at least one of the one direction and the other direction as a central axis. The second group of driven parts has an axis along at least one of the one direction and the other direction at a resonance frequency determined by the second group of driven parts and the fourth elastic part. The fine vibration is applied to rotate the driven portion of the second group so as to rotate while resonating as a central axis.

  According to this aspect, the driven part is divided into a first group of driven parts that rotate while resonating at one resonance frequency and a second group of driven parts that rotate while resonating at another resonance frequency. be able to. Even in this case, since a non-directional force due to micro vibration is applied, the micro vibration causes the first group driven parts to move in one direction using the elasticity of the first elastic portion. And the axis along at least one of the other directions is rotated as the central axis, and the second group driven parts are moved along at least one of the one direction and the other direction by utilizing the elasticity of the second elastic portion. The axis can be rotated around the center axis. For this reason, even when the driven part is divided into a plurality of driven parts that rotate while resonating at different resonance frequencies with axes along different directions as the central axis, a single application part is used. Each of the plurality of driven parts can be suitably rotated.

  In another aspect of the driving apparatus of the present embodiment, the application unit is a single application unit.

  According to this aspect, it is not always necessary to provide the two application units even when the driven unit is biaxially rotated. For this reason, it is possible to apply a fine vibration for performing the biaxial rotation drive of the driven part using a single application part. However, it goes without saying that multi-axis rotational drive of two or more axes may be performed.

  In another aspect of the driving apparatus of the present embodiment, the elastic portion has elasticity such that the driven object is rotated about an axis along another direction different from the one direction as a central axis. (I) the driven part so that the driven part rotates at a resonance frequency determined by the driven part and the elastic part while resonating with an axis along the one direction as a central axis. And (ii) a driving force for rotating the driven part so that the driven part rotates about an axis along the other direction as a central axis.

  According to this aspect, the driven portion (more specifically, a structure that suspends the driven portion using the elasticity of the elastic portion (more specifically, the first elastic portion described later), The driven part and the structure composed of the second base part and the second elastic part, which will be described in detail later, are rotated about the axis along the other direction as the central axis, and the elastic part (more specifically, described later). The driven portion can be rotated about the axis along one direction as the central axis by utilizing the elasticity of the second elastic portion. For this reason, as will be described in detail later with reference to the drawings, it is possible to suitably perform the biaxial rotation drive of the driven part.

  In this aspect, in particular, in the above-described driving device aspect, the driven part resonates along one direction and the other direction when the driven part rotates, whereas the driven part moves. In this case, the driven part resonates along one direction, but the driven part does not need to resonate along the other direction. At this time, the application unit uses the non-directional force described above as the force for rotating the driven unit about the axis along one direction as the central axis, while the driven unit is moved in the other direction. It is not necessary to use the non-directional force described above as a force for rotating the axis along the axis. That is, the application unit uses the non-directional force described above as the force for rotating the driven unit about the axis along one direction as the central axis, while the driven unit is moved along the other direction. The above-described directional force (that is, a force that directly acts in the direction of rotating the driven part about the axis along the other direction as the central axis) can be used as the force for rotating the selected axis as the central axis Good. Even if comprised in this way, the biaxial rotation drive of a to-be-driven part can be performed suitably.

  The applying unit may use the above-described non-directional force in addition to the above-described directional force as the force for rotating the driven unit about the axis along the other direction as the central axis. . That is, you may rotate a to-be-driven part centering on the axis along another direction using the force which combined the force with directionality, and the force without directionality.

  In another aspect of the driving apparatus of the present embodiment, the base portion includes a first base portion and a second base portion surrounded by the first base, and the elastic portion includes (i) the first base. And (ii) the second base having elasticity so as to connect the portion and the second base portion and rotate the second base portion about the axis along the other direction as a central axis; And a second elastic part having elasticity that connects the driven part and the driven part and rotates the driven part about an axis along the one direction as a central axis, and the application part comprises (i ) For rotating the driven part so that the driven part rotates while resonating with the axis along the one direction as a central axis at a resonance frequency determined by the driven part and the second elastic part. The fine vibration, and (ii) the second base portion is centered on the axis along the other direction. Add s driving force husband for rotating said second base unit for rotation axis.

  According to this aspect, the second base portion is rotated about the axis along the other direction as a central axis by utilizing the elasticity of the first elastic portion, and the driven portion is utilized by utilizing the elasticity of the second elastic portion. An axis along one direction can be rotated as a central axis. Here, since the driven portion is connected to the second base portion via the second elastic portion, the second base portion rotates about the axis along the other direction as a central axis, and as a result, the driven portion The drive unit also rotates about the axis along the other direction as the central axis. For this reason, as will be described in detail later with reference to the drawings, it is possible to suitably perform the biaxial rotation drive of the driven part.

  In this aspect, in particular, in the above-described driving device aspect, the driven part resonates along one direction and the other direction when the driven part rotates, whereas the driven part moves. In this case, the driven part resonates along one direction, but the driven part does not need to resonate along the other direction. At this time, the application unit uses the non-directional force described above as the force for rotating the driven unit about the axis along one direction as the central axis, while the driven unit is moved in the other direction. It is not necessary to use the non-directional force described above as a force for rotating the axis along the axis. That is, the application unit uses the non-directional force described above as the force for rotating the driven unit about the axis along one direction as the central axis, while the driven unit is moved along the other direction. The above-described directional force (that is, a force that directly acts in the direction of rotating the driven part about the axis along the other direction as the central axis) can be used as the force for rotating the selected axis as the central axis Good. Even if comprised in this way, the biaxial rotation drive of a to-be-driven part can be performed suitably.

  In this aspect, the application unit rotates (i) while the driven unit resonates with the axis along the one direction as a central axis at a resonance frequency determined by the driven unit and the second bullet unit. And (ii) rotating the second base portion so that the second base portion rotates about an axis along the other direction as a central axis. These driving forces may be applied to the second base portion.

  If comprised in this way, the biaxial rotation drive of a to-be-driven part can be performed suitably by applying a fine vibration and driving force to a 2nd base part.

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

  As described above, according to the driving device of the present embodiment, the base unit, the driven unit, the elastic unit, and the applying unit are provided. Therefore, the driven part can be rotated using a force other than a directional force.

  Hereinafter, embodiments of the driving 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 First, a first embodiment of a MEMS scanner will be described with reference to FIGS.

(1-1) Basic Configuration First, 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 according to the first embodiment.

  As shown in FIG. 1, the MEMS scanner 100 according to the first embodiment includes a base 110 that constitutes a specific example of the “base portion” described above, and a torsion bar that constitutes a specific example of the “elastic portion” described above. 120a and 120b, a mirror 130 that constitutes a specific example of the “driven part” described above, and a drive source part 140 that constitutes a specific example of the “applying part” described above.

  The base 110 has a frame shape with a gap inside. That is, the first 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. 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 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 mirror 130 is disposed.

  The torsion bar 120a is a member having elasticity such as a spring made of silicon, copper alloy, iron-based 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 a side 131 of the mirror that faces the side 111 inside the base 110 along the Y-axis direction.

  Similarly, the torsion bar 120b is a member having elasticity such as a spring made of 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 connected to the inner side (in other words, the region portion) 111 of the base 110 along the Y-axis direction (that is, the base 110 to which one end 121a of the torsion bar 120a is connected. Is connected to the inner side 112 of the base 110 opposite to the inner side 111). The other end 122b of the torsion bar 120b is connected to the side 132 of the mirror 130 that faces the inner side 112 of the base 110 along the Y-axis direction.

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

  The drive source unit 140 applies micro vibrations necessary for rotating the mirror 130 about the axis along the Y-axis direction to the base 110. In addition, as long as the drive source part 140 can apply a slight vibration to the base 110, the arrangement mode may be arbitrarily determined. Further, the present invention is not limited to applying force to the base 110, and may be configured to apply force to other positions.

  More specifically, the drive source unit 140 includes a piezoelectric element 140a, a transmission branch 140b, and a support plate 140c that has a gap 140d and is fixed to the base 110 via the transmission branch 140b. On the support plate 140c, the piezoelectric element 140a is sandwiched between branches 140e and 140f which are defined by the gap 140d and face each other. By applying a voltage to the piezoelectric element 140a via an electrode (not shown), the piezoelectric element 140a changes its shape. This change in the shape of the piezoelectric element 140a causes a change in the shape of the branches 140e and 140f. As a result, changes in the shapes of the branches 140e and 140f are transmitted to the base 110 through the transmission branch 140b as fine vibration (or wave energy) as will be described in detail later.

  The drive source unit 140 is not limited to a drive source unit that applies microvibration due to the piezoelectric effect, but a drive source unit that applies microvibration due to electromagnetic force and a drive source unit that applies force due to electrostatic force. It may be used. Of course, it goes without saying that other methods may be used.

  For example, the driven source unit that applies a slight vibration caused by electromagnetic force includes a magnetic pole disposed on the branch 140e and a coil disposed on the branch 140f. In this case, a desired voltage is applied to the coil at a desired timing from a drive source unit control circuit (not shown). A current flows by applying a voltage to the coil, and electromagnetic interaction occurs between the coil and the magnetic pole. As a result, electromagnetic force due to electromagnetic interaction is generated. This electromagnetic force causes the shape of the branches 140e and 140f to change. As a result, changes in the shapes of the branches 140e and 140f are transmitted to the base 110 through the transmission branch 140b as fine vibration (or wave energy) as will be described in detail later.

  In addition, the driven source unit that applies the minute vibration caused by the electrostatic force is disposed on the branch 140e and the comb-shaped first electrode disposed on the branch 140f and distributed between the first electrodes. 2 electrodes. In this case, a desired voltage is applied to the first electrode at a desired timing from a drive source unit control circuit (not shown). Here, 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 electrode and the second electrode. This electrostatic force causes the shape of the branches 140e and 140f to change. As a result, changes in the shapes of the branches 140e and 140f are transmitted to the base 110 through the transmission branch 140b as fine vibration (or wave energy) as will be described in detail later.

(1-2) Operation of MEMS Scanner Next, with reference to FIG. 2, an operation mode of the MEMS scanner 100 according to the first embodiment (specifically, an operation mode of rotating the mirror 130) will be described. . FIG. 2 is a plan view conceptually showing an operation mode of the MEMS scanner 100 according to the first embodiment.

  During operation of the MEMS scanner 100 according to the first embodiment, the drive source unit 140 applies a voltage to the piezoelectric element 140a via an electrode (not shown) so that the piezoelectric element 140a expands and contracts along the direction of the X axis in FIG. Is applied. As a result, the shape of the piezoelectric element 140a changes and the shapes of the branches 140e and 140f change. As a result, changes in the shapes of the branches 140e and 140f are transmitted to the base 110 through the transmission branch 140b as fine vibration (or wave energy) as will be described in detail later.

  Here, since the change in the shape of the piezoelectric element 140a is in the direction of the X axis in FIG. 2, the change in the shape of each of the branches 140e and 140f caused by the change in the shape of the piezoelectric element 140a is the change in the X axis in FIG. Occurs along the direction. Here, the force itself generated by the change in the shape of the piezoelectric element 140a is different from the rotation direction of the mirror 130 (that is, the rotation direction with the direction along the Y axis as the central axis). On the other hand, the change in the shape of the piezoelectric element 140a (that is, the change in the shape of each of the branches 140e and 140f) is a slight vibration (in other words, wave energy) via the support plate 140c and the transmission branch 140b. It is transmitted to the base 110 as a non-directional force). More specifically, the drive source unit 140 applies, as wave energy, a fine vibration that propagates in 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 140 generates micro vibrations that propagate as energy (in other words, wave energy that expresses the force) in the base 110. 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 to the base 110 from the drive source unit 140 is transmitted from the base 110 to the torsion bars 120a and 120b. After that, as shown in FIG. 2, 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 the mirror 130 is rotated. 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 130. 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 130 can be rotated. As a result, as shown in FIG. 2, the mirror 130 rotates about the axis along the Y-axis direction as the central axis. More specifically, the mirror 130 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). 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.

  At this time, the mirror 130 rotates so as to resonate at a resonance frequency determined according to the mirror 130 and the torsion bars 120a and 120b. For example, if the moment of inertia about the axis along the Y-axis of the mirror 130 is I and the torsion spring constant is k when the torsion bars 120a and 120b are regarded as one spring, the mirror 130 is ( 1 / (2π)) × √ (k / I) resonance frequency (or (1 / (2π)) × √ (k / I) 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 140 applies slight vibration in a manner synchronized with the resonance frequency so that the mirror 130 resonates at the resonance frequency described above.

  Here, with reference to FIG. 3, the force without directionality resulting from the fine vibration applied from the drive source unit 140 will be further described. Here, FIG. 3 is a plan view for explaining a force having no directivity due to fine vibration applied from the drive source unit 140. In the following description, the description will be given using a configuration in which the drive source unit 140 applies a slight vibration caused by electromagnetic force.

  As shown in FIG. 3, the drive source unit 140 is a transmission branch 140b and a support plate 140c connected to the first base 110-1 via the transmission branch 140b and facing each other along the X-axis direction. A support plate 140c including branches 140x and 140y, and a coil 140z wound around each of the branches 140x and 140y. Also, the shapes and characteristics of the branches 140x and 140y are the same, and the characteristics (eg, the number of turns) of the coil 140z wound around the branch 140x and the characteristics (eg, the number of turns) of the coil 140z wound around the branch 140y. ) Shall be the same.

  Here, when a current is passed through the coil 140 wound around each of the branches 140x and 140y, a force (that is, a negative direction of the X axis) pulled toward the branch 140y with respect to the branch 140x by electromagnetic interaction. If a force acting in the direction toward the left side in FIG. 3 is generated, the force that is pulled toward the branch 140x also in the direction of the branch 140x (that is, the positive direction of the X axis). Thus, a force acting in the direction toward the right side in FIG. 3 is generated. Since these forces are opposite to each other and have the same magnitude, they do not cause external acceleration or generate their own acceleration, and the point P where the branches 140x and 140y join (in other words, Only a slight vibration is transmitted to the point P) on the transmission branch 140b. As a result, the force at point P is not directional. Similarly, when electromagnetic force causes a force to be pulled away from the branch 140y with respect to the branch 140x (that is, a force acting in the positive direction of the X axis and toward the right side in FIG. 3), A force that is pulled away from the branch 140x (that is, a force acting in the negative direction of the X axis and toward the left side in FIG. 3) is also generated on the branch 140y. Since these forces are opposite to each other and have the same magnitude, they do not cause any external acceleration, nor do they cause any acceleration, and at the point P) where the branches 140x and 140y join, Only vibration is transmitted. As a result, the force at point P is not directional.

  However, according to the experiment by the inventors of the present application, a fine vibration (that is, a wave energy having a non-directional force) propagates in the base 110 by the above configuration, and as a result, the mirror 130 moves in the Y-axis direction. It has been found that the axis along the axis rotates. That is, the micro-vibration applied by the drive source unit 140 propagates in the base 110 as the above-described non-directional force (in other words, wave energy), so that the mirror 130 is centered on the axis along the Y-axis direction. As it turns out to rotate.

  Thus, in the first embodiment, the mirror 130 is rotated about the axis along the Y-axis direction as the central axis so that the mirror 130 resonates at a resonance frequency determined according to the mirror 130 and the torsion bars 120a and 120b. be able to. That is, in the first embodiment, the mirror 130 self-resonates with the Y axis as the central axis.

  Here, “resonance” is a phenomenon in which infinite displacement occurs due to repeated infinitesimal forces. For this reason, even if the force applied to rotate the mirror 130 is reduced, the rotation range of the mirror 130 (in other words, the amplitude in the rotation direction) can be increased. That is, the force required for rotating the mirror 130 can be relatively reduced. For this reason, it is possible to reduce the amount of electric power required to apply the force necessary to rotate the mirror 130. Therefore, the mirror 130 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 a mirror 130 is rotationally driven by applying a so-called directional force (for example, the base 110 itself is largely twisted in the rotational direction of the mirror 130 and the twist is applied to the torsion bar 120a. And a configuration in which the mirror 130 is rotationally driven by being added directly to the mirror 130b or 120b) will be described as an example. In this case, a force having directionality to rotate the mirror 130 about the axis along the Y-axis direction (that is, the base 110 is twisted to rotate about the axis along the Y-axis direction as the central axis). Force) must be applied from a certain drive source unit 140. For this reason, the arrangement position of the drive source unit 140 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 140 is limited depending on the direction in which the force is applied.

  However, in the first embodiment, since a non-directional force due to microvibration is applied, the arrangement position of the drive source unit 140 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 140 is not limited depending on the direction of rotation of the mirror 130. That is, no matter what the arrangement position of the drive source unit 140 is set, the slight vibration (that is, nondirectional force) applied from the drive source unit 140 uses the elasticity of the torsion bars 120a and 120b. Thus, the mirror 130 can be rotated with 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.

(2) Second Embodiment First, a second embodiment of the MEMS scanner will be described with reference to FIGS.

(2-1) Basic Configuration First, the basic configuration of the MEMS scanner 101 according to the second embodiment will be described with reference to FIG. FIG. 4 is a plan view conceptually showing the basic structure of the MEMS scanner 101 according to the second embodiment.

  As shown in FIG. 4, the MEMS scanner 101 according to the second embodiment includes the first base 110-1 that constitutes a specific example of the above-described “base part (or first base part)” and the above-described “ The first torsion bar 120a-1 constituting one specific example of the “elastic portion (or first elastic portion)” and the first specific example constituting the above-described “elastic portion (or first elastic portion)” The torsion bar 120b-1, the second base 110-2 that constitutes one specific example of the above-described "base part (or second base part)", and the above-described "elastic part (or second elastic part)". A second torsion bar 120a-2 that constitutes a specific example of the above, a second torsion bar 120b-2 that constitutes a specific example of the above-mentioned "elastic part (or second elastic part)", Mirror 130 constituting a specific example of “driving unit” And a drive unit 140 which constitutes one specific example of the "applied part" described above.

  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. 4 and two sides extending in the X-axis direction (that is, the axial 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. 4, the first base 110-1 has a square shape, but 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 101 according to the second embodiment, and is fixed to a substrate or a support member (not shown) (in other words, the MEMS scanner 101). It is preferably fixed inside the system.

  In addition, in FIG. 4, although the example in which the 1st base 110-1 has a frame shape is shown, it cannot be overemphasized that it may have another shape. For example, the first base 110-1 may have a U-shape in which a part of the side 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, 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 mirror 130 is disposed.

  The first torsion bar 120a-1 is a member having elasticity such as a spring made of silicon, copper alloy, iron alloy, other metal, resin, or the like. The first torsion bar 120a-1 is arranged 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 that has a short side that extends in the X-axis direction and a long side that extends in the Y-axis direction, depending on the setting state 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.

  Similarly, the first torsion bar 120b-1 is a member having elasticity such as a spring made of silicon, copper alloy, iron alloy, other metal, resin, or the like. The first torsion bar 120b-1 is arranged 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 shape having a short side extending in the X-axis direction and a long side extending in the Y-axis direction according to the setting state of the resonance frequency described later. Also good. One end 121b-1 of the first torsion bar 120b-1 is an inner side (in other words, a region portion) 115-1 (that is, the first torsion) along the X-axis direction. It 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 of the bar 120a-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 facing the inner side 116-1 of the first base 110-1 along the X-axis direction. 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. 4 and two sides extending in the X-axis direction (that is, the axial 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. 4, the second base 110-2 has a square shape, but is not limited to this. For example, other shapes (for example, a rectangular shape such as a rectangle or a circular shape) Shape etc.).

  Further, the second base 110-2 is arranged to be suspended or supported by the first torsion bars 120a-1 and 120b-1 in the gap 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.

  In addition, in FIG. 4, although the 2nd base 110-2 has shown the example which has a frame shape, it cannot be overemphasized that it may have another shape. For example, the second base 110-2 may have a U-shape in which a part of the side 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 an axis) and two planes distributed on a plane defined by a 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 mirror 130 is disposed.

  The second torsion bar 120a-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 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 having a short side extending in the Y-axis direction and a long side extending in the X-axis direction, 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 131 of the mirror 130 facing the side 111-2 on the inner side of the second base 110-2 along the Y-axis direction. The

  Similarly, the second torsion bar 120b-2 is a member having elasticity such as a spring made of 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 Y-axis direction and a long side that extends in the X-axis direction, 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 (in other words, a region portion) 111-2 (that is, the second torsion) of the second base 110-2 along the Y-axis direction. 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 one end 121a-2 of the bar 120a-2 is connected. . The other end 122b-2 of the second torsion bar 120b-2 is connected to the other side 132 of the mirror 130 facing the inner side 112-2 of the second base 110-2 along the direction of the Y-axis. The

  The mirror 130 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 130 is configured to rotate about the direction of the Y axis as the central axis by the elasticity of the second torsion bars 120a-2 and 120b-2.

  The drive source unit 140 is necessary for rotating the second base 110-2 around the axis along the X-axis direction and rotates the mirror 130 around the axis along the Y-axis direction. The fine vibration necessary for the purpose is applied to the first base 110-1. In addition, as long as the drive source part 140 can apply the above-mentioned fine vibration to the 1st base 110-1, the arrangement | positioning aspect may be determined arbitrarily. In addition, the first base 110-1 is not limited to the minute vibration, and may be configured to be able to apply the minute vibration to other positions.

  More specifically, the drive source unit 140 includes a piezoelectric element 140a, a transmission branch 140b, and a support plate 140c that has a gap 140d and is fixed to the first base 110-1 via the transmission branch 140b. Yes. On the support plate 140c, the piezoelectric element 140a is sandwiched between branches 140e and 140f which are defined by the gap 140d and face each other. By applying a voltage to the piezoelectric element 140a via an electrode (not shown), the piezoelectric element 140a changes its shape. This change in the shape of the piezoelectric element 140a causes a change in the shape of the branches 140e and 140f. As a result, changes in the shapes of the branches 140e and 140f 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.

  The drive source unit 140 is not limited to a drive source unit that applies micro vibrations due to the piezoelectric effect, but a drive source unit that applies micro vibrations due to electromagnetic force and a drive source unit that applies micro vibrations due to electrostatic force. May be used. Of course, it goes without saying that other methods may be used.

  For example, the driven source unit that applies a slight vibration caused by electromagnetic force includes a magnetic pole disposed on the branch 140e and a coil disposed on the branch 140f. In this case, a desired voltage is applied to the coil at a desired timing from a drive source unit control circuit (not shown). Application of voltage to the coil causes electromagnetic interaction between the coil and the magnetic pole. As a result, electromagnetic force due to electromagnetic interaction is generated. This electromagnetic force causes the shape of the branches 140e and 140f to change. As a result, changes in the shapes of the branches 140e and 140f 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.

  In addition, the driven source unit that applies the minute vibration caused by the electrostatic force is disposed on the branch 140e and the comb-shaped first electrode disposed on the branch 140f and distributed between the first electrodes. 2 electrodes. In this case, a desired voltage is applied to the first electrode at a desired timing from a drive source unit control circuit (not shown). Here, 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 electrode and the second electrode. This electrostatic force causes the shape of the branches 140e and 140f to change. As a result, changes in the shapes of the branches 140e and 140f 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.

(2-2) Operation of MEMS Scanner Next, with reference to FIG. 5, an operation mode of the MEMS scanner 101 according to the second embodiment (specifically, an operation mode of rotating the mirror 130) will be described. . FIG. 5 is a plan view conceptually showing an operation mode of the MEMS scanner 101 according to the second embodiment.

  During operation of the MEMS scanner 101 according to the second embodiment, the drive source unit 140 applies a voltage to the piezoelectric element 140a via an electrode (not shown) so that the piezoelectric element 140a expands and contracts along the direction of the X axis in FIG. Apply. As a result, the shape of the piezoelectric element 140a changes and the shapes of the branches 140e and 140f change. As a result, the changes in the shapes of the branches 140e and 140f are transmitted to the first base 110-1 via the transmission branch 140b as vibration energy instead of vibration itself as will be described in detail later.

  Here, since the change in the shape of the piezoelectric element 140a is in the direction of the X axis in FIG. 5, the change in the shape of each of the branches 140e and 140f caused by the change in the shape of the piezoelectric element 140a is the change in the X axis in FIG. Occurs along the direction. Here, the force itself generated by the change in the shape of the piezoelectric element 140a is the rotation direction of the second base 110-2 (that is, the rotation direction centered on the direction along the X axis) and the rotation direction of the mirror 130 ( That is, it is different from each of the rotation directions with the direction along the Y axis as the central axis. On the other hand, the change in the shape of the piezoelectric element 140a (that is, the change in the shape of each of the branches 140e and 140f) is a slight vibration (in other words, wave energy) via the support plate 140c and the transmission branch 140b. As a force having no directionality). More specifically, the drive source unit 140 propagates in the first base 110-1 while eliminating the twist in the rotation direction of the first base 110-1 itself with respect to the first base 110-1 serving as the foundation. The minute vibration is added as wave energy. In other words, the driving source unit 140 uses the first base 110-1 as energy (in other words, energy for expressing the force) instead of applying a force that imparts a twist in the rotational direction to the first base 110-1. As) adding a propagating micro-vibration. Such fine vibration becomes a force having no directionality at the time of propagation in the first base 110-1. 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 first base 110-1 to which such a minute vibration is applied is a medium that propagates a minute vibration (in other words, wave energy) rather than an object in which the first base 110-1 itself vibrates. Become.

  As a result, the slight vibration applied to the first base 110-1 from the drive source unit 140 is transmitted from the first base 110-1 to the first torsion bars 120a-1 and 120b-1. After that, as shown in FIG. 5, the micro-vibration (in other words, wave energy) propagating in the first base 110-1 is in a direction according to the elasticity of the first torsion bars 120 a-1 and 120 b-1 itself. The first torsion bars 120a-1 and 120b-1 are rotated toward the front, and the second base 110-2 is rotated. In other words, the micro vibration that has propagated through the first base 110-1 appears in the form of rotation of the first torsion bars 120a-1 and 120b-1 and rotation of the second base 110-2. 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 first base 110-1 can be extracted outside in the form of vibration (more specifically, resonance), and as a result, the second base 110-2 that supports the mirror 130. Can be rotated. As a result, as shown in FIG. 5, the second base 110-2 rotates about the axis along the X-axis direction as the central axis. More specifically, the second base 110-2 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 second base 110-2 includes a suspended portion including the second base 110-2 (in other words, a second base 110-2 suspended by the first torsion bars 120a-1 and 120b-1. And the first torsion bars 120a-1 and 120b-1 so as to resonate at a resonance frequency. 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 and 120b provided in the second base 110-2) -2 and the second base 110-2 including the respective masses of the mirrors 130, the inertial moment about the axis along the X-axis of the suspended portion consisting of the entire system is I1 and the first torsion bar 120a Assuming that the torsional spring constant when -1 and 120b-1 are regarded as one spring is k1, the second base 110-2 is (1 / (2π)) × √ (k1 / I1). Resonance frequency (or (1 / (2π)) × √ (k1 / I1) N times or 1 / N times (where N is an integer equal to or greater than 1)). The axis along the X-axis direction is the central axis To rotate in. For this reason, the drive source unit 140 applies fine vibration in a manner synchronized with the resonance frequency so that the second base 110-2 resonates at the resonance frequency described above.

  Similarly, the fine vibration applied to the first base 110-1 from the drive source unit 140 causes the first torsion bars 120a-1 and 120b-1 and the second base 110-2 from the first base 110-1. To the second torsion bars 120a-2 and 120b-2. After that, as shown in FIG. 5, the micro-vibration (in other words, wave energy) propagating in the first base 110-1 is in a direction according to the elasticity of the second torsion bars 120 a-2 and 120 b-2 itself. The second torsion bars 120a-2 and 120b-2 are rotated or the mirror 130 is rotated. In other words, the micro vibration that has propagated through the first base 110-1 appears in the form of rotation of the second torsion bars 120 a-1 and 120 b-1 and rotation of the mirror 130. 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 first base 110-1 and the second base 110-2 can be extracted outside in the form of vibration (more specifically, resonance), and as a result, the mirror 130 is rotated. Can be made. As a result, as shown in FIG. 5, the mirror 130 rotates about the axis along the Y-axis direction as the central axis. More specifically, the mirror 130 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 130 rotates so as to resonate at a resonance frequency determined according to the mirror 130 and the second torsion bars 120a-2 and 120b-2. For example, if the moment of inertia about the axis of the mirror 130 along the Y axis is m2 and the second torsion bars 120a-2 and 120b-2 are regarded as one spring, the torsion spring constant is k2. For example, the mirror 130 has a resonance frequency (or (1 / (2π)) × √ (k2 / I2) N times or N minutes specified by (1 / (2π)) × √ (k2 / I2). 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 140 applies slight vibration in a manner synchronized with the resonance frequency so that the mirror 130 resonates at the resonance frequency described above.

  Here, with reference to FIG. 6, the force without directionality resulting from the fine vibration applied from the drive source unit 140 will be further described. Here, FIG. 6 is a plan view for explaining the non-directional force applied from the drive source unit 140 due to the slight vibration. In the following description, the description will be given using a configuration in which the drive source unit 140 applies a slight vibration caused by electromagnetic force.

  As shown in FIG. 6, the drive source unit 140 is a transmission branch 140b and a support plate 140c connected to the first base 110-1 via the transmission branch 140b and facing each other along the X-axis direction. A support plate 140c including branches 140x and 140y, and a coil 140z wound around each of the branches 140x and 140y. Also, the shapes and characteristics of the branches 140x and 140y are the same, and the characteristics (eg, the number of turns) of the coil 140z wound around the branch 140x and the characteristics (eg, the number of turns) of the coil 140z wound around the branch 140y. ) Shall be the same.

  Here, when a current is passed through the coil 140 wound around each of the branches 140x and 140y, a force (that is, a negative direction of the X axis) pulled toward the branch 140y with respect to the branch 140x by electromagnetic interaction. When a force acting in the direction toward the left side in FIG. 6 is generated, the force that is pulled toward the branch 140x also in the direction of the branch 140x (that is, the positive direction of the X axis). Thus, a force acting in the direction toward the right side in FIG. 6 is generated. Since these forces are opposite to each other and have the same magnitude, they do not cause external acceleration or generate their own acceleration, and the point P where the branches 140x and 140y join (in other words, Only a slight vibration is transmitted to the point P) on the transmission branch 140b. As a result, the force at point P is not directional. Similarly, when electromagnetic force causes a force to be pulled away from the branch 140y with respect to the branch 140x (that is, a force acting in the positive direction of the X axis and toward the right side in FIG. 6), A force to be pulled away from the branch 140x (that is, a force acting in the negative direction of the X axis toward the left side in FIG. 6) is also generated on the branch 140y. Since these forces are opposite to each other and have the same magnitude, they do not cause external acceleration or generate their own acceleration, and there is a slight vibration at the point P where the branches 140x and 140y join. Only communicated. As a result, the force at point P is not directional.

  However, according to the experiment of the present inventor, a fine vibration (that is, a wave energy having no directivity) propagates in the first base 110-1 according to the above configuration, and as a result, the second base 110 -2 rotates with the axis along the X-axis direction as the central axis, and the mirror 130 rotates with the axis along the Y-axis direction as the central axis. In other words, the minute vibration applied by the drive source unit 140 propagates in the first base 110-1 as the above-described non-directional force (in other words, wave energy), so that the second base 110-2 moves along the X axis. It has been found that the mirror 130 rotates about the axis along the direction as the central axis, and the mirror 130 rotates about the axis along the Y-axis direction as the central axis.

  In addition, a graph of actual experimental results will be described with reference to FIG. FIG. 7 is a graph showing experimental results. In the experiment, the mirror 130 having a size of “3 mm × 4 mm” is used, the resonance frequency of the second base 110-2 is set to 700 Hz, and the resonance frequency of the mirror 130 is set to 5.3 kHz. It is not intended that the present invention be limited to configurations having these numerical values.

  Fig.7 (a) shows the aspect of rotation centering on the axis | shaft along the X-axis direction of the 2nd base 110-2. The horizontal axis of FIG. 7A indicates the frequency of the signal applied to the drive source unit 140, and the vertical axis of FIG. 7A indicates the rotation amount (left side) and the rotation phase (second rotation) of the second base 110-2. Right side). As can be seen from the graph shown in FIG. 7A, when the signal frequency applied to the drive source unit 140 is changed, the second base 110 is changed when the signal repetition frequency becomes “700 Hz”. It can be seen that the rotation amount of -2 is maximized and the phase of rotation is reversed. This indicates that the second base 110-2 rotates around the axis along the X-axis direction as the central axis while resonating at a frequency of “700 Hz”. In other words, by applying a non-directional force due to micro vibrations, the second base 110-2 can rotate about the axis along the X-axis direction as the central axis while resonating at a frequency of “700 Hz”. It has been confirmed by experiments.

  FIG. 7B shows a mode of rotation about the axis along the Y-axis direction of the mirror 130 as the central axis. The horizontal axis in FIG. 7B indicates the frequency of the signal applied to the drive source unit 140, and the vertical axis in FIG. 7B indicates the amount of rotation (left side) and the phase of rotation (right side) of the mirror 130. ing. As can be seen from the graph shown in FIG. 7B, when the frequency of the signal applied to the drive source unit 140 is changed, the mirror repeats when the signal repetition frequency becomes “5.3 kHz”. It can be seen that the amount of rotation 130 is maximized and the phase of rotation is reversed. This indicates that the mirror 130 rotates around the axis along the Y-axis direction as the central axis while resonating at a frequency of “5.3 kHz”. In other words, by applying a non-directional force due to microvibration, the mirror 130 resonates at a frequency of “5.3 kHz” and rotates about the axis along the Y-axis direction as a center axis. It has been confirmed.

  Thus, in the second embodiment, the axis along the Y-axis direction is the central axis so that the mirror 130 resonates at a resonance frequency determined according to the mirror 130 and the second torsion bars 120a-2 and 120b-2. And the second base 110-2 resonates at a resonance frequency determined according to the second base 110-2 and the first torsion bars 120a-1 and 120b-1. The second base 110-2 can be rotated about the axis along the direction as the central axis. Here, considering that the mirror 130 is connected to the second base 110-2 via the second torsion bars 120a-2 and 120b-2, the axis along the X-axis direction is set as the central axis. In accordance with the rotation of the second base 110-2, the mirror 130 also rotates about the axis along the X-axis direction as the central axis. As a result, the mirror 130 can be rotated so that the mirror 130 resonates with the X axis and the Y axis as the center axes. That is, in the second embodiment, the mirror 130 self-resonates with the X axis and the Y axis as the center axes.

  Here, “resonance” is a phenomenon in which infinite displacement occurs due to repeated infinitesimal forces. For this reason, even if the force applied to rotate the mirror 130 is reduced, the rotation range of the mirror 130 (in other words, the amplitude in the rotation direction) can be increased. That is, the force required for rotating the mirror 130 can be relatively reduced. For this reason, it is possible to reduce the amount of electric power required to apply the force necessary to rotate the mirror 130. Therefore, the mirror 130 can be moved more efficiently, and as a result, low power consumption of the MEMS scanner 101 can be realized.

  In addition, in the second 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 mirror 130 (for example, the first base 110-1 itself is largely twisted, and the twist is applied to the first torsion bar 120a. -1 and 120b-1, the second torsion bars 120a-2 and 120b-2, and the mirror 130 by being directly applied to the mirror 130) will be described as an example. In this case, a force having directionality to rotate the mirror 130 about the axis along the X-axis direction (that is, the first base 110-1 is rotated about the axis along the X-axis direction as the central axis). Force that twists the mirror 130 from a certain drive source unit 140, and also has a directionality force that rotates the mirror 130 about the axis along the Y-axis direction (that is, the first base 110 is It is necessary to apply from the other drive source unit 140 a force that twists to rotate the axis along the direction as the central axis. In other words, when the biaxial rotational drive of the mirror 130 is performed by applying a directional force, usually, the MEMS scanner must include two or more drive source units 140. In other words, when the biaxial rotation of the mirror 130 is performed by applying a directional force, only one force acting in one direction can be applied from one drive source unit 140. The MEMS scanner must include at least one drive source unit 140.

  However, in the second embodiment, the mirror 130 can be driven to rotate biaxially by applying a force having no directivity due to the minute 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 140 is the first torsion bar 120a-1. Of the second torsion bars 120a-2 and 120b-2 (that is, the elasticity of rotating the second base 110-2 supporting the mirror 130 about the axis along the X-axis direction). Utilizing elasticity (that is, elasticity for rotating the mirror 130 with the axis along the Y-axis direction as the central axis), the mirror 130 is rotated with the axes along the X-axis and Y-axis directions as the central axes. be able to. That is, in the second embodiment, it is not always necessary to provide the two drive source sections 140 even when the mirror 130 is biaxially rotated. For this reason, it is possible to apply a force having no directivity due to the fine vibration for performing the biaxial rotation driving of the mirror 130 using the single driving source unit 140.

  In addition, even if a force acting in two directions can be applied from one drive source unit, when performing biaxial rotation driving of the mirror 130 by applying a force having directionality, After all, components acting in two directions (that is, a force component having a directionality that rotates the mirror 130 around the axis along the X-axis direction as a central axis, and a component along the Y-axis direction). It is necessary to apply a force having a direction component that rotates the axis about the axis. However, in the second 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 140 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 140 is not limited depending on the direction of rotation of the mirror 130. That is, no matter what the position of the drive source unit 140 is set, the minute vibration (that is, nondirectional force) applied from the drive source unit 140 is the first torsion bars 120a-1 and 120b. -1 and the second torsion bars 120a-2 and 120b-2 can be used to rotate the mirror 130 about the X-axis and Y-axis directions as central axes. Thereby, the design freedom of the MEMS scanner 101 can be relatively increased. This is very advantageous in practice for MEMS scanners where the size or design constraints of each component are large.

(3) Third Embodiment Next, a third embodiment of the MEMS scanner will be described with reference to FIGS. FIG. 8 is a plan view conceptually showing the basic configuration of the MEMS scanner 102 having one configuration according to the third embodiment, and FIG. 9 is a MEMS scanner 103 having another configuration according to the third embodiment. It is a top view which shows notionally the fundamental structure notionally. In addition, about the structure same as the MEMS scanner 100 which concerns on 1st Example mentioned above, and the MEMS scanner 101 which concerns on 2nd Example, the same referential mark is attached | subjected and the detailed description is abbreviate | omitted.

  As shown in FIG. 8, the first MEMS scanner 102 according to the third embodiment is similar to the MEMS scanner 101 according to the second embodiment in that the first base 110-1, the first torsion bar 120a-1, The first torsion bar 120b-1, the second base 110-2, the second torsion bar 120a-2, the second torsion bar 120b-2, the mirror 130, and the drive source unit 150 are provided.

  In particular, the first MEMS scanner 102 according to the third embodiment differs from the MEMS scanner 101 according to the second embodiment in the arrangement position of the drive source unit 150. Specifically, in the first MEMS scanner 102 according to the third embodiment, the drive source unit 150 is arranged so as to apply a force to the second base 110-2. More specifically, the drive source unit 150 included in the first MEMS scanner 102 according to the third embodiment includes two drive source units 150a and 150b arranged with the mirror 130 interposed therebetween. The drive source unit 150a is a drive source unit that applies a force due to an electrostatic force, and includes a comb-like first electrode 151a disposed on the inner side 111-1 of the first base 110-1, and a second base. The second electrode 152a is disposed on the outer side 113-2 of 110-2 and distributed between the first electrodes 151a. The drive source unit 150b is a drive source unit that applies a force due to an electrostatic force, and includes a comb-like first electrode 151b disposed on the inner side 112-1 of the first base 110-1, a first 2 and a second electrode 152b distributed between the first electrodes 151b and disposed on the outer side 114-2 of the base 110-2.

  Each of the drive source units 150a and 150b according to the third embodiment applies a force necessary for rotating the second base 110-2 around the axis along the X-axis direction to the second base 110-2. Add. In particular, each of the drive source units 150a and 150b applies a force that relatively vibrates the second base 110-2 to the second base 110-2 in order to rotate the second base 110-2. More specifically, when a voltage is applied to each of the first electrodes 151a and 151b and the second electrodes 152a and 152b, between the first electrode 151a and the second electrode 152a, and between the first electrode 151b and the second electrode. An electrostatic force attracting each other is generated between 152b and 152b. This electrostatic force acts on the second base 110-2 as a force directed from the back side to the near side or from the near side to the far side with respect to the paper surface of FIG. As a result, the second base 110-2 vibrates relatively greatly, and rotates about the axis along the X axis as the central axis. In other words, each of the drive source units 150a and 150b applies a force (that is, a directional force) that rotates the second base 110-1 around the axis along the X-axis direction as a central axis. By directly adding to the second base 110-2, the second base 110-2 is rotated about the axis along the X-axis direction as the central axis. At the same time, each of the drive source units 150a and 150b uses the force that rotates the second base 110-2 about the axis along the X-axis direction as a central axis, and rotates the mirror 130 along the Y-axis direction. Rotate around the center axis. In other words, the mirror 130 rotates about the axis along the Y-axis direction as a central axis by using a force that rotates the second base 110-2 about the axis along the X-axis direction as a central axis. Here, the electrostatic force generated between the first electrode 151a and the second electrode 152a and between the first electrode 151b and the second electrode 152b causes the second base 110-1 to move along the X axis. Although it has the directionality which rotates the axis along a direction as a central axis, it does not have the directionality which rotates the mirror 130 about an axis along the direction of the Y-axis. Therefore, when the mirror 130 is rotated about the axis along the Y-axis direction as a central axis using the force that rotates the second base 110-2 about the axis along the X-axis direction, The force corresponds to the force having no direction described above.

  In order to realize such an operation, each of the drive source units 150a and 150b has a signal (a signal for generating a force for rotating the second base 110-2 around the axis along the X-axis direction as a central axis). That is, a signal synchronized with a resonance frequency when the mirror 130 is rotated about the axis along the Y-axis direction as a central axis (that is, a voltage signal for generating micro vibrations) is superimposed on the voltage signal. Signal is added as an input signal.

  For this reason, according to the first MEMS scanner 102 of the third embodiment, the mirror 130 (with the non-directional force is used to rotate the mirror 130 about the axis along the Y axis as the central axis. In other words, a directional force is used to rotate the second base 110-2) supporting the mirror 130 around the axis along the X axis. Even if comprised in this way, the biaxial rotation drive of the mirror 130 can be performed suitably.

  As shown in FIG. 9, the second MEMS scanner 103 according to the third embodiment is similar to the MEMS scanner 101 according to the second embodiment in that the first base 110-1, the first torsion bar 120a-1, The first torsion bar 120b-1, the second base 110-2, the second torsion bar 120a-2, the second torsion bar 120b-2, the mirror 130, and the drive source unit 160 are provided.

  In particular, the second MEMS scanner 103 according to the third embodiment differs from the MEMS scanner 101 according to the second embodiment in the arrangement position of the drive source unit 160. Specifically, in the second MEMS scanner 103 according to the third embodiment, the drive source unit 160 is arranged so that a force can be applied to the second base 110-2. That is, the arrangement position of the drive source unit 160 in the second MEMS scanner 103 according to the third embodiment is the same as the arrangement position of the drive source section 150 in the first MEMS scanner 102 according to the third embodiment. The second MEMS scanner 103 according to the third embodiment is different from the first MEMS scanner 102 according to the third embodiment in that the configuration of the drive source unit 160 is different. More specifically, the drive source unit 160 included in the second MEMS scanner 103 according to the third embodiment is a drive source unit that applies a force due to electromagnetic force, and has a frame shape of the second base 110-2. , A magnetic pole 162a disposed on the inner side 111-1 of the first base 110-1, and a magnetic pole 162b disposed on the inner side 112-1 of the first base 110-1. With.

  The drive source unit 160 according to the third embodiment applies a force necessary to rotate the second base 110-2 about the axis along the X-axis direction as the central axis. In particular, the drive source unit 160 applies a force that relatively vibrates the second base 110-2 to the second base 110-2 in order to rotate the second base 110-2. More specifically, for example, a current is passed in the counterclockwise direction in FIG. 6 to the coil 161, and a magnetic flux is generated from the magnetic pole 162a toward the upper side from the lower side in FIG. 6, and from the magnetic pole 162b in FIG. Assume that a magnetic flux is generated from the lower side to the upper side. In this case, the upper sides 111-2 and 113-2 of the coil 161 (that is, the second base 110-2 on which the coil 161 is disposed) act from the near side to the far side with respect to the paper surface of FIG. Power is applied. Similarly, the lower sides 112-2 and 114-2 of the coil 161 (that is, the second base 110-2 on which the coil 161 is disposed) act from the back side to the front side with respect to the paper surface of FIG. The power to do is added. As a result, the second base 110-2 rotates about the axis along the X-axis direction as the central axis. The force applied at this time is a force that directly acts to rotate the second base 110-2 around the axis along the X-axis direction as the central axis, and is the above-described directional force. At the same time, each of the drive source units 160 uses the force that rotates the second base 110-2 about the axis along the X-axis direction as the center axis, and centers the mirror 130 on the axis along the Y-axis direction. Rotate as an axis. In other words, the mirror 130 rotates about the axis along the Y-axis direction as a central axis by using a force that rotates the second base 110-2 about the axis along the X-axis direction as a central axis. Here, the electromagnetic force generated in the coil 161 has a directionality that causes the second base 110-1 to rotate about the axis along the X-axis direction as a central axis at the time of generation, but the mirror 130 is It does not have the directionality to rotate around the axis along the Y-axis direction as the central axis. Therefore, when the mirror 130 is rotated about the axis along the Y-axis direction as a central axis using the force that rotates the second base 110-2 about the axis along the X-axis direction, The force corresponds to the force having no direction described above.

  For this reason, according to the second MEMS scanner 103 of the third embodiment, the mirror 130 (the mirror 130 () is used while using a non-directional force to rotate the mirror 130 about the axis along the Y axis. In other words, a directional force is used to rotate the second base 110-2) supporting the mirror 130 around the axis along the X axis. Even if comprised in this way, the biaxial rotation drive of the mirror 130 can be performed suitably.

  In the third embodiment, the mirror 130 is rotated about the axis along the X axis while using a non-directional force to rotate the mirror 130 about the axis along the Y axis. In order to make it use the power with directionality. However, both a directional force and a non-directional force may be used to rotate the mirror 130 about the axis along the X axis as a central axis. In other words, in order to rotate the mirror 130 around the predetermined axis, only non-directional force may be used, only directional force may be used, non-directional force and A combination of directional forces may be used.

(4) Fourth Embodiment Next, a fourth embodiment of the MEMS scanner will be described with reference to FIG. FIG. 10 is a plan view conceptually showing the basic structure of the MEMS scanner 104 according to the fourth example. In addition, about the structure same as the MEMS scanner 100 which concerns on 1st Example mentioned above, and the MEMS scanner 101 which concerns on 2nd Example, the same referential mark is attached | subjected and the detailed description is abbreviate | omitted.

  As shown in FIG. 10, the MEMS scanner 104 according to the fourth example includes a first base 110-1 and a drive source unit 140, similarly to the MEMS scanner 101 according to the second example.

  In particular, the MEMS scanner 104 according to the fourth embodiment includes a plurality of mirrors 130-1 each configured to rotate around an axis along the X-axis direction, and each along the Y-axis direction. A plurality of mirrors 130-2 configured to rotate about an axis as a central axis, and a plurality of mirrors 130-1 each connecting a corresponding one of the plurality of mirrors 130-1 and the first base 110-1. A plurality of torsion bars 120 a-1 and 120 b-1, and a plurality of torsion bars 120 a-2 and 120 b-2 each connecting the corresponding mirror 130-2 of the plurality of mirrors 130-2 and the first base 110-1. And. The MEMS scanner 104 according to the fourth embodiment corresponds to a configuration obtained by dividing the mirror 130 included in the MEMS scanner 102 according to the second embodiment.

  Each of the plurality of torsion bars 120a-1 and 120b-1 has the same configuration and characteristics as the first torsion bars 120a-1 and 120b-1. One end of each of the plurality of torsion bars 120a-1 and 120b-1 is connected to the first base 110-1, and the other end of each of the plurality of torsion bars 120a-1 and 120b-1 corresponds. Connected to mirror 130-1. In addition, each of the plurality of torsion bars 120a-1 and 120b-1 has elasticity to rotate the corresponding mirror 130-1 about the axis along the X-axis direction as a central axis.

  Each of the plurality of torsion bars 120a-2 and 120b-2 has the same configuration and characteristics as the second torsion bars 120a-2 and 120b-2 described above. One end of each of the plurality of torsion bars 120a-2 and 120b-2 is connected to the first base 110-1, and the other end of each of the plurality of torsion bars 120a-2 and 120b-2 corresponds. Connected to mirror 130-2. In addition, each of the plurality of torsion bars 120a-2 and 120b-2 has elasticity to rotate the corresponding mirror 130-2 around the axis along the Y-axis direction as a central axis.

  Each of the plurality of mirrors 130-1 has substantially the same configuration as that of the above-described mirror 130, and is suspended by the corresponding torsion bars 120a-1 and 120b-1 in the space inside the first base 110-1. Arranged to be lowered or supported. Further, each of the plurality of mirrors 130-1 is set so that the resonance frequency is “f1”. That is, each of the plurality of mirrors 130-1 has a resonance frequency of “f1”, and each of the plurality of mirrors 130-1 has a moment of inertia and a plurality of torsion about the axis along the X-axis direction. The respective torsion spring constants of the bars 120a-1 and 120b-1 are set. Each of the plurality of mirrors 130-1 is configured to rotate about an axis along the X-axis direction as a central axis by the elasticity of the torsion bars 120a-1 and 120b-1.

  Each of the plurality of mirrors 130-2 has substantially the same configuration as that of the above-described mirror 130, and is suspended in the gap inside the first base 110-1 by the corresponding torsion bars 120a-2 and 120b-2. Arranged to be lowered or supported. Further, each of the plurality of mirrors 130-2 is set so that the resonance frequency is “f2”. That is, each of the plurality of mirrors 130-2 has a moment of inertia and a plurality of torsion about the axis along the Y-axis direction of each of the mirrors 130-1 so that the resonance frequency is “f2”. The respective torsion spring constants of the bars 120a-2 and 120b-2 are set. Each of the plurality of mirrors 130-2 is configured to rotate about the axis along the Y-axis direction as a central axis by the elasticity of the torsion bars 120a-2 and 120b-2.

  Such a MEMS scanner 104 can be used as a display device, for example. Specifically, the plurality of mirrors 130-1 are used as mirrors for performing vertical scanning by reflecting light from a light source. In the example shown in FIG. 10, it is preferable that the three mirrors 130-1 correspond to red (R), green (G), and blue (B), respectively. Similarly, the plurality of mirrors 130-2 are used as mirrors for performing horizontal scanning by reflecting light from the light source. In the example shown in FIG. 10, it is preferable that the three mirrors 130-2 correspond to red (R), green (G), and blue (B), respectively.

  According to the MEMS scanner 104 according to the fourth embodiment having such a configuration, a minute vibration (that is, a force having no directivity) is applied to the first base 110-1 from the drive source unit 140. By utilizing the elasticity of each of the plurality of torsion bars 120a-1 and 120b-1 by the nondirectional force caused by the vibration, each of the plurality of mirrors 130-1 is made to resonate at one resonance frequency f1. A plurality of mirrors 130-2 are rotated while being resonated at another resonance frequency f2 using the elasticity of each of the plurality of torsion bars 120a-2 and 120b-2 while rotating about the axis along the axis direction as a central axis. Can be rotated with the axis along the direction of the Y-axis as the central axis. More specifically, by supplying a signal in which a signal synchronized with one resonance frequency f1 and a signal synchronized with another resonance frequency f2 are superposed to the drive source unit 140, resonance occurs at one resonance frequency f1. The plurality of mirrors 130-1 can be rotated while being rotated, and the plurality of mirrors 130-2 can be rotated while being resonated at another resonance frequency f2. In other words, by supplying only a signal synchronized with one resonance frequency f1 to the drive source unit 140, the plurality of mirrors 130-1 can be rotated while resonating at one resonance frequency f1, The plurality of mirrors 130-2 are not rotated. Similarly, by supplying only the signal synchronized with the other resonance frequency f2 to the drive source unit 140, the plurality of mirrors 130-2 can be rotated while resonating at the other resonance frequency f2. The plurality of mirrors 130-1 are not rotated. For this reason, even if the MEMS scanner 104 includes a plurality of mirrors 130-1 and 130-2 having different resonance frequencies, the single drive source unit 140 is used to configure the plurality of mirrors 130-1 and 130-2. Each can be suitably rotated.

  In the above example, each of the plurality of mirrors 130-1 having the resonance frequency f1 is rotated about the axis along the X-axis direction as the central axis, and the plurality of mirrors 130-2 having the resonance frequency f2. An example is described in which each of these is rotated about an axis along the direction of the Y axis as the central axis. However, each of the plurality of mirrors 130 having the resonance frequency f1 is rotated about the axis along the X-axis direction as the central axis, and each of the plurality of mirrors 130 having the resonance frequency f1 is aligned along the Y-axis direction. The plurality of mirrors 130 having the resonance frequency f2 are rotated about the axis along the X-axis direction, and the plurality of mirrors 130 having the resonance frequency f2 are rotated. You may comprise so that it may rotate by making the axis along the direction of a Y-axis into a central axis. For example, as shown in FIG. 11, a plurality of first mirrors 130-3 that resonate at one resonance frequency f1 and rotate about an axis along the X-axis direction as a central axis resonate at another resonance frequency f2. However, a plurality of second mirrors 130-4 that rotate about the axis along the X-axis direction as a central axis, and a plurality of axes that rotate about the axis along the Y-axis direction while resonating at one resonance frequency f1. You may comprise so that the 3rd mirror 130-5 and the some 4th mirror 130-6 which rotates centering on the axis | shaft along the direction of the Y-axis, resonating with other resonance frequency f2 may be provided. In this case, by supplying a signal in which a signal synchronized with one resonance frequency f1 and a signal synchronized with another resonance frequency f2 are superimposed on the drive source unit 140, a plurality of signals are generated while resonating at one resonance frequency f1. The first mirror 130-3 is rotated about an axis along the X-axis direction as a central axis, and the plurality of third mirrors 130-5 are rotated along the Y-axis direction while resonating at one resonance frequency f1. The second mirror 130-4 can be rotated about the axis along the direction of the X axis while resonating at another resonance frequency f2, and can be rotated at the other resonance frequency f2. However, the plurality of fourth mirrors 130-6 can be rotated about the axis along the Y-axis direction as the central axis. In other words, by supplying only a signal synchronized with one resonance frequency f1 to the drive source unit 140, the plurality of first mirrors 130-3 are moved along the X-axis direction while resonating at one resonance frequency f1. The plurality of third mirrors 130-5 can be rotated about the axis along the Y-axis direction while resonating at the resonance frequency f1 while the other axis is rotated. While resonating at the frequency f2, the plurality of second mirrors 130-4 are rotated about the axis along the X-axis direction as the central axis, and while resonating at the other resonance frequency f2, the plurality of fourth mirrors 130-6 are rotated along the Y axis. The axis along the direction is not rotated as the central axis. Similarly, by supplying only the signal synchronized with the other resonance frequency f2 to the drive source unit 140, the plurality of second mirrors 130-4 are moved along the X-axis direction while resonating at the other resonance frequency f2. The plurality of fourth mirrors 130-6 can be rotated about the axis along the Y-axis direction while resonating at the other axis and while resonating at another resonance frequency f2. The plurality of first mirrors 130-3 are rotated about the axis along the X-axis direction as the central axis while resonating at the frequency f1, and the plurality of third mirrors 130-5 are rotated along the Y-axis while resonating at one resonance frequency f1. The axis along the direction is not rotated as the central axis.

  Even with this configuration, even when the MEMS scanner 104 includes a plurality of mirrors 130-3 to 130-6 having different resonance frequencies and rotation directions, a plurality of mirrors can be formed using the single drive source unit 140. The desired mirror of 130-3 and 130-6 can be suitably rotated.

  Needless to say, the various configurations described in the first to third embodiments may be appropriately applied to the MEMS scanner 104 according to the fourth embodiment.

  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 MEMS Scanner 110 Base 120 Torsion Bar 130 Mirror 140 Drive Source Unit

Claims (12)

A base part;
A rotatable driven part; and
An elastic part having elasticity that connects the base part and the driven part and rotates the driven part around an axis along one direction;
The minute vibration for rotating the driven portion so that the driven portion rotates while resonating with an axis along the one direction as a central axis at a resonance frequency determined by the driven portion and the elastic portion. An application unit that is applied to the base unit.   The drive device according to claim 1, wherein the micro vibration is non-directional micro vibration or anisotropic micro vibration as non-directional vibration energy.   2. The driving device according to claim 1, wherein the application unit applies the minute 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.   The driving device according to claim 1, wherein the application unit applies the minute vibration generated by a force acting in a direction along a surface of the driven unit when stationary. The elastic portion has elasticity such that the driven portion rotates about an axis along another direction different from the one direction as a central axis,
The application unit rotates the driven unit so that the driven unit rotates at a resonance frequency determined by the driven unit and the elastic unit while resonating with the axis along the one direction as a central axis. And the driven part so that the driven part rotates at a resonance frequency determined by the suspended part including the driven part and the elastic part while resonating with the axis along the other direction as a central axis. The drive device according to claim 1, wherein the micro vibration for rotating the motor is applied to the base portion. The base portion includes a first base portion and a second base portion at least partially surrounded by the first base,
The elastic portion has (i) elasticity that connects the first base portion and the second base portion and rotates the second base portion about an axis along the other direction as a central axis. A second elastic portion having elasticity that connects the second base portion and the driven portion and rotates the driven portion around an axis along the one direction as a central axis; With
The application unit rotates at a resonance frequency determined by the suspended portion including the second base portion and the first elastic portion while the second base portion resonates with an axis along the other direction as a central axis. And the axis of the driven part along the one direction at a resonance frequency determined by the fine vibration for rotating the second base part and determined by the driven part and the second elastic part. The driving apparatus according to claim 5, wherein the fine vibration for rotating the driven part so as to rotate while resonating is applied.   The application unit is configured to rotate the second base so that the second base rotates at a resonance frequency determined by the second base and the first elastic part while resonating with an axis along the other direction as a central axis. The driven part rotates at a resonance frequency determined by the driven part and the second elastic part while resonating about the axis along the one direction as a central axis. The drive device according to claim 6, wherein the fine vibration for rotating the driven part is applied to the first base part. The driven part is divided into a plurality of driven parts,
The elastic portion connects (i) a first group of driven portions of the plurality of driven portions and the base portion, and connects the first group of driven portions to the one direction and the one portion. A third elastic portion having elasticity so as to rotate about an axis along at least one of other directions different from the direction as a central axis, and (ii) the driven group of the first group of the plurality of driven portions A second group of driven parts different from the part is connected to the base part, and the second group of driven parts is rotated about an axis along at least one of the one direction and the other direction as a central axis. A fourth elastic portion having elasticity to allow
The application unit has an axis along which at least one of the one direction and the other direction has the driven portion of the first group at a resonance frequency determined by the driven portion of the first group and the third elastic portion. The fine vibration for rotating the driven portion of the first group so as to rotate while resonating as a central axis, and the resonance frequency determined by the driven portion of the second group and the fourth elastic portion The fine for rotating the second group driven parts so that the second group driven parts rotate while resonating about an axis along at least one of the one direction and the other direction as a central axis. The drive device according to claim 1, wherein vibration is applied.   The driving device according to claim 1, wherein the application unit is a single application unit. The elastic portion has elasticity such that the driven portion rotates about an axis along another direction different from the one direction as a central axis,
The application unit is configured to (i) rotate the driven unit so that the driven unit rotates at a resonance frequency determined by the driven unit and the elastic unit while resonating with an axis along the one direction as a central axis. (Ii) applying a driving force for rotating the driven portion so that the driven portion rotates about an axis along the other direction as a central axis. The drive device according to claim 1, wherein the drive device is characterized. The base portion includes a first base portion and a second base portion surrounded by the first base,
The elastic portion has (i) elasticity that connects the first base portion and the second base portion and rotates the second base portion about an axis along the other direction as a central axis. A second elastic portion having elasticity that connects the second base portion and the driven portion and rotates the driven portion around an axis along the one direction as a central axis; With
The application unit is configured to (i) rotate the driven unit so that the driven unit resonates at a resonance frequency determined by the driven unit and the second elastic unit while resonating about an axis along the one direction. (Ii) a driving force for rotating the second base portion so that the second base portion rotates about an axis along the other direction as a central axis. The driving device according to claim 10, wherein each of the driving devices is added.   The application unit is configured to (i) rotate the driven unit so that the driven unit resonates at a resonance frequency determined by the driven unit and the second elastic unit while resonating about an axis along the one direction. The fine vibration for rotating the drive unit, and (ii) the driving force for rotating the second base unit so that the second base unit rotates about the axis along the other direction as a central axis, respectively. The driving device according to claim 11, wherein the second base portion is added to the second base portion.

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