JP7044498B2 - Actuator - Google Patents

Description

The present invention relates to actuators applicable, for example, when driving a MEMS device.

As an actuator for driving a MEMS device, for example, a coil portion is arranged on a base portion (frame) that supports a driven portion such as a mirror, and the coil portion is deformed and vibrated to make the driven portion a coil portion. It is known that the coil is rotated on an axis different from the axis of rotation of the above (see Patent Document 1).

However, in the above case, as the coil portion rotates, the base portion (frame) is deformed by receiving a force, so that a desired rotational operation of the driven portion can be obtained. If unnecessary deformation occurs, it may not be possible to perform the desired operation of the driven portion.

Further, when trying to drive the driven portion in two axes, problems such as an increase in size of the device and an increase in power consumption may occur in addition to the above problems.

Japanese Patent No. 6014234

The present invention has been made in view of the above points, and while avoiding problems related to deformation of a base portion such as a frame that supports a driven portion such as a mirror, the device can be made smaller, lighter, and power-saving. It is an object of the present invention to provide an actuator capable of performing an improved two-axis drive of a driven portion.

The actuator for achieving the above object is connected to the fixed portion, and includes a drive portion and a base portion connected by the first connecting portion so that the rotation centers are arranged on the first axis, respectively, and the base portion of the base portion. Inside, the driven portion is connected by a second connecting portion extending in the direction of the second axis perpendicular to the first axis, and a structure asymmetrical with respect to the first axis is provided.

In the above actuator, the drive unit and the base unit are connected and arranged by the first connection unit so that the rotation center is arranged on the first axis, so that the deformation of the base unit due to the rotation of the drive unit is performed. You can avoid the problem. On top of this, by further providing an asymmetrical structure with respect to the first axis, it is possible to create a slightly unbalanced state with respect to the axial direction of the first axis for the drive generated in the drive unit. As a result, the rotational force around the first axis of the drive unit causes the rotation of the driven unit connected to the inside of the base unit by the second connection unit to be perpendicular to the first axis as well as around the first axis. It is possible to drive around two axes. That is, it is possible to drive the driven portion in two axes only by rotating the coil side around one axis. Therefore, the structure for driving the drive unit can be simplified, and the device can be made smaller, lighter, and power-saving.

In a specific aspect of the present invention, a structure asymmetrical with respect to the first axis is provided between the drive portion and the first connection portion. In this case, it is possible to provide a structure for biaxially driving the driven portion between the driven portion separated from the driven portion and the first connecting portion.

In another aspect of the invention, the first connection is offset from the position of the first axis. In this case, by making the first connecting portion asymmetrical with respect to the first axis, it is possible to drive the driven portion in two axes.

In yet another aspect of the invention, the center of the base is on the axis of the first axis and the first connection is offset with respect to the base. In this case, torque can be applied to the base portion centered on the axis of the first axis from a position offset by the first connection portion, so that the torque can be applied not only around the first axis but also around the second axis. It is possible to make it.

In yet another aspect of the present invention, the drive unit has a weight arranged with the position of the center of gravity shifted from the first axis. In this case, by having a weight, the drive unit can have a structure asymmetrical with respect to the first axis.

In yet another aspect of the present invention, in the drive unit, the driven unit is driven around the second axis by generating vibration with a drive frequency higher than the vibration of the drive frequency corresponding to the rotational force around the first axis. Let me. In this case, the driven portion can be driven around the first axis by the vibration of a relatively low drive frequency, and the driven portion can be driven around the second axis by the vibration of a relatively high drive frequency.

In yet another aspect of the present invention, the drive unit and the first connection unit are in a pair configuration of one arranged on one side of the base portion and one arranged on the other side of the base portion. In this case, the paired configuration can make the operation of the driven unit more stable.

In yet another aspect of the present invention, one side and the other side of the paired drive unit and the first connection unit are arranged point-symmetrically with respect to the center of the base unit and are driven in synchronization with each other. In this case, while providing an asymmetrical structure with respect to the first axis, it is possible to improve the symmetry of the device as a whole, improve the stability of operation, and suppress the bias of the load applied to the device.

In yet another aspect of the present invention, the drive unit is a coil unit, further comprising a magnetic field applying unit that applies a magnetic field to the coil unit, and the magnetic field applying unit receives a rotational force around a first axis generated in the coil unit. Generates a magnetic field in the corresponding unidirectional direction. In this case, the magnetic field applying portion can have a simple structure.

(A) is a block diagram for explaining the actuator according to the first embodiment, and (B) is a conceptual diagram for explaining the force acting at the time of driving. It is a figure for demonstrating the actuator of one modification. (A) is a block diagram for explaining the actuator according to the second embodiment, and (B) is a conceptual diagram for explaining the center of gravity. It is a figure for demonstrating the actuator of one modification. (A) is a block diagram for explaining the actuator according to the third embodiment, and (B) is a diagram conceptually showing transmission of a drive signal to a coil.

[First Embodiment]
Hereinafter, an example of the actuator according to the first embodiment will be described with reference to FIG. FIG. 1A is a block diagram for explaining an example of the actuator according to the present embodiment. The actuator 100 as one aspect of the present embodiment is an optical scanning in a distance image device capable of acquiring distance image data about an object by scanning the object with pulsed light such as a laser pulse. It can be applied as a device for performing the above. It can also be applied as a display device that displays an image on a screen by irradiating pulsed light at the right timing according to optical scanning.

As shown in FIG. 1A, the actuator 100 is connected to a coil unit 10 which is a driving unit that rotates, a magnetic field applying unit 20 that applies a magnetic field to the coil unit 10, and a coil unit 10. The frame-shaped base portion (movable frame) 30, the first connecting portion CN1 connecting the coil portion 10 and the base portion 30, and the first connecting portion CN1 arranged inside the frame-shaped base portion 30 and connected to the base portion 30. A frame-shaped fixing portion that is connected to the driven portion 40, the second connecting portion CN2 that connects the base portion 30 and the driven portion 40, and the coil portion 10 and the base portion 30, respectively, to fix the entire device. It is equipped with 50.

Here, in FIG. 1 (A), the surface formed by the fixed portion 50 which is the outer frame of the entire device shown in a plane is defined as a reference surface (horizontal plane), and the reference surface in FIG. 1 (A). The horizontal direction is the X direction, and the direction perpendicular to the X direction is the Y direction. The frame-shaped fixing portion 50 has a rectangular shape due to two sides extending in the X direction and two sides extending in the Y direction. Further, the direction perpendicular to both the X direction and the Y direction, that is, the direction perpendicular to the reference plane is defined as the Z direction.

With the above configuration, the actuator 100 transmits the excitation force generated on the coil portion 10 side to the driven portion 40 side, and causes the driven portion 40 to extend along the X direction with the first axis AX1. It is rotatable with respect to two axes with the second axis AX2 extending along the Y direction perpendicular to the X direction.

Further, in the illustrated example, the coil portion 10 and the base portion 30 are connected to the fixed portion 50 via a pair of rod-shaped connecting members CP and CP extending along the axis of the first axis AX1. .. Further, the coil portion 10, the base portion 30, and the driven portion 40 all have a symmetrical shape with the first axis AX1 as the central axis. Therefore, the coil portion 10 and the base portion 30 are rotatable about the first axis AX1 in the direction indicated by the arrow R1 (rotatable about the axis of the first axis AX1). Further, the driven portion 40 connected to the base portion 30 that can rotate around the axis of the first axis AX1 can also rotate around the axis of the first axis AX1. Further, the driven portion 40 is arranged inside the frame-shaped base portion 30, and is connected to the base via the second connecting portions CN2 and CN2, which are a pair of rod-shaped connecting members extending along the second axis AX2. It is connected to the unit 30. As a result, the driven unit 40 can rotate about the second axis AX2 in the direction indicated by the arrow R2. That is, the axis can be rotated around the axis of the second axis AX2.

A control current for rotating the driven unit 40 is supplied to the coil unit 10 from a power source (not shown). The control current is an alternating current including a signal component having a frequency corresponding to the drive frequency of the driven unit 40.

Hereinafter, each part constituting the actuator 100 will be described more specifically.

First, the coil portion 10 has a loop-like structure in which windings made of a material having a relatively high conductivity such as gold or copper are provided along a rectangular frame. In particular, two of the four sides constituting the rectangular portion extend along the X direction and the current (alternating current) I flows in this direction, so that the direction of the magnetic field generated in the magnetic field applying portion 20 It is designed to cross. As a result, the coil unit 10 receives Lorentz force from the magnetic field applying unit 20 and rotates about the axis at a runout angle and speed appropriately adjusted according to the scanning range, speed, and the like required by the driven unit 40. In particular, here, as described above, the coil portion 10 has a symmetrical shape with the first axis AX1 as the central axis, and stably rotates with the connecting member CP connected to the fixed portion 50 as the rotation center axis. It works. Further, as described above, the coil portion 10 is connected to the base portion 30 by the first connecting portion CN1. As a result, the coil portion 10 transmits the rotational drive force or the rotational torque corresponding to the generated exciting force to the base portion 30 via the first connection portion CN1.

The magnetic field applying unit 20 is configured by, for example, combining a plurality of permanent magnets MG, MG, ..., And applies a magnetic field to the coil unit 10. Further, it is possible to apply a magnetic field by substituting a part of the permanent magnets MG, MG, ... With a yoke. In the illustrated example, the permanent magnets MG, MG, ... Are appropriately combined and installed to form the magnetic field applying portion 20, and the magnetic field B is generated in the −Y direction. As described above, the coil portion 10 receives a force F (see FIG. 1 (B)) in the Z direction when a current I flows in the X direction orthogonal to the Y direction (Fleming's left-hand rule). From the above point of view, the magnetic field applying unit 20 generates the magnetic field B in one direction (−Y direction) corresponding to the rotational force that rotates the coil unit 10 around the axis of the first axis AX1.

The first connection portion CN1 is a member having elasticity, for example, made of silicon, a copper alloy, an iron-based alloy, another metal or the like, or made of a resin. As described above, and as shown in the figure, the first connection portion CN1 extends along the X direction and connects the coil portions 10 and the base portion 30 arranged side by side in the X direction. Here, in particular, the first connection portion CN1 is arranged offset from the position of the first axis AX1 to the + Y side. That is, the first connection portion CN1 has a structure asymmetrical with respect to the first axis AX1. In the present embodiment, since the first connection portion CN1 has an asymmetric structure, it is possible to create a slightly unbalanced state with respect to the rotational drive of the first axis AX1 in the axial direction (X direction). .. This makes it possible to drive the rotation of the driven portion 40 not only around the first axis AX1 but also around the second axis AX2 perpendicular to the first axis AX1.

As described above, the base portion 30 is a frame-shaped member having a driven portion 40 inside, and in the illustrated example, the base portion 30 is arranged in parallel with the coil portion 10 in the X direction and is relatively relative to the coil portion 10. Is also arranged on the −X side, and is connected to the coil portion 10 via the first connecting portion CN1 on the + X side. Further, the base portion 30 has a symmetrical shape with the first axis AX1 as the central axis as described above, and is fixed via a connecting member CP extending along the first axis AX1 on the −X side. It is connected to 50. As a result, the base portion 30 receives (transmits) the rotational drive force or rotational torque corresponding to the exciting force generated in the coil portion 10 via the first connection portion CN1, and the rotation center of the first axis AX1. It is a movable frame that rotates as an axis. Further, the base portion 30 can transmit a rotational driving force or a rotational torque to the driven portion 40 via the second connecting portions CN2 and CN2. Further, the base portion 30 has a shape symmetrical to the second axis AX2 even when viewed as a central axis.

Looking at the base portion 30 and the first connection portion CN1 described above, the center of the base portion 30 is on the axis of the first axis AX1, whereas the first connection portion CN1 is the base portion. It can also be considered that they are arranged offset from 30.

The second connecting portion CN2 is a member having elasticity, and is particularly configured to be able to respond to vibration at a frequency relatively higher than that of the first connecting portion CN1. As described above, the second connecting portion CN2 is a pair of rod-shaped members extending along the second axis AX2, and is connected to each end of the driven portion 40 in the Y direction.

The driven portion 40 is a member having a flat surface portion (in the figure, an elliptical surface portion). For example, the flat surface portion or a part thereof is formed as a movable mirror surface (light reflecting surface), and the driven portion 40 is rotationally driven. By doing so, it becomes possible to perform optical scanning while inputting and reflecting light. As described above, the driven portion 40 is arranged inside the frame-shaped base portion 30 and is connected to the base portion 30 via the pair of second connecting portions CN2 and CN2.

Since the driven portion 40 is connected to the base portion 30, the driven portion 40 receives a rotational drive force or a rotational torque from the coil portion 10 side together with the base portion 30 to perform a rotational operation with the first axis AX1 as the central axis of rotation. do. Further, in the present embodiment, the first connection portion CN1 has a structure asymmetrical with respect to the first axis AX1 (or the first connection portion CN1 is offset with respect to the center of the base portion 30). It creates a slightly unbalanced state with respect to the rotational drive of the uniaxial AX1 in the axial direction (X direction). Therefore, regarding the rotational driving force or rotational torque generated on the coil portion 10 side, not only the component around the first axis AX1 but also the component around the second axis AX2 perpendicular to the first axis AX1 is included. It is in a state, and in this state, it is transmitted from the coil portion 10 side to the driven portion 40 side. In the present embodiment, the driven unit 40 is resonantly driven by utilizing the generated components around the second axis AX2. As a result, the driven portion 40 enables a rotational operation with the second axis AX2 as the rotation center axis while being supported by the second connection portion CN2.

In the above configuration, of the actuator 100, the coil portion 10 to the first connection portion CN1, that is, the coil portion 10, the magnetic field applying portion 20, and the first connection portion CN1 exert a force that becomes a drive source for rotational drive. It is a rotational drive source unit DS to be generated, and the base portion 30 to the driven portion 40, that is, the base portion 30, the second connection portion CN2 and the driven portion 40 receive a force from the rotational drive source unit DS and are desired. It can also be regarded as a moving unit RE that performs a rotating motion. That is, the structure is such that the side including the coil portion 10 as the drive source is separated (separated) from the base portion 30 (movable frame) to be rotationally driven and the driven portion 40 side. This makes it possible to avoid the problem of deformation of the base portion 30 due to the rotation of the coil portion 10.

Hereinafter, the rotational drive of the driven unit 40 will be described from the viewpoint of the action from the rotary drive source unit DS side to the operating unit RE. As illustrated in FIG. 1 (A), in the rotary drive source unit DS, from the relationship between the current I flowing in the −X direction and the magnetic field B generated in the −Y direction, conceptually in FIG. 1 (B). As shown, a force F in the opposite direction, which is a couple equidistant from the center CT of the connecting member CP, is generated in the ± Z direction. Therefore, the coil portion 10 of the rotation drive source portion DS rotates with respect to the central CT. At this time, the force Fa acts on the base portion 30 constituting the moving portion RE from the position of the first connecting portion CN1, that is, the position shifted from the central CT to the + Y side. In this embodiment, in this way, the position of the force Fa on which the rotational drive source unit DS acts is displaced (shifted) and is in an unbalanced state. Therefore, not only the vibration action around the first axis AX1 but also the vibration action (micro-vibration) around the second axis AX2 occurs, and on the coil portion 10 side, that is, the rotation drive source portion DS side, around one axis (in the X direction). Despite causing only rotational movement around the 1st axis AX1 extending along the axis, around the 2nd axis (around the 1st axis AX1 extending along the X direction and in the Y direction) on the driven portion 40 side receiving the force. Around the second axis AX2 extending along the axis), that is, a two-axis drive can be performed.

Hereinafter, an example of the operation of rotationally driving the driven unit 40 in the actuator 100 will be described. Here, it is assumed that the control current supplied to the coil unit 10 includes signal components (a drive signal on the low-speed drive side and a drive signal on the high-speed drive side) having two frequencies corresponding to the drive frequency of the driven unit 40. Around the first axis AX1 extending along the X direction is driven at low speed (for example, frequency 60 Hz), and around the second axis AX2 extending along the Y direction is driven at high speed (for example, frequency 30 kHz). .. That is, here, the driven unit 40 is driven around the second axis AX2 by generating a vibration with a drive frequency higher than the vibration of the drive frequency corresponding to the rotational force around the first axis AX1. It has become.

The frequency of the low-speed drive signal is non-resonant drive (forced drive) or resonance drive with respect to the natural frequency (resonance frequency) inherent in the driven unit 40, and is a high-speed drive signal. The frequency of is resonantly driven. By applying vibration by these driving signals, that is, the driving signal on the low-speed driving side and the driving signal on the high-speed driving side, the actuator 100 drives the driven portion 40 to rotate.

First, the operation around the first axis AX1 extending along the X direction will be described. The first connection portion CN1 is capable of following the rotational movement at low speed drive (60 Hz), that is, while maintaining a rigid body, the operation due to the rotational force received from the coil portion 10 is extended to the base portion 30. It is transmitted to the drive unit 40 to rotate them. That is, while the first connecting portion CN1 is used as a torsion bar (spring for rotation), the driven portion 40 as a mirror rotates around the first axis AX1 extending along the X direction. As for the circumference of the first axis AX1, the coil portion 10 and the base portion 30 are in stable operation because the center of the rotational force and the center of rotation coincide with each other.

Next, the operation around the second axis AX2 extending along the Y direction will be described. As described above, in the present embodiment, the first connection portion CN1 connecting the coil portion 10 and the base portion 30 is offset with respect to the first axis AX1. Therefore, in the case of FIG. 1A of the frame-shaped base portion 30 symmetrical with respect to the first axis AX1 as the central axis, the rotation in the coil portion 10 is caused from the upper right (+ X side and + Y side) portion. The force Fa will be received as the exciting force. Along with this exciting force, an oblique rotational torque including components in the X direction and the Y direction is generated in the base portion 30. Since the period of this rotational torque corresponds to the resonance frequency peculiar to the driven portion 40, the driven portion 40 is resonantly rotated. In particular, the component in the Y direction of this rotational torque causes a rotational operation around the second axis AX2. In other words, by adopting a frequency suitable for resonantly driving the driven unit 40 as a high-speed drive (for example, a frequency of 30 kHz), the driven unit 40 can be rotated around the second axis AX2. The drive signal on the high-speed drive side at this time has a value that is significantly different from the drive signal on the low-speed drive side, and the influence of the drive signal on the high-speed drive side on the operation on the low-speed drive side can be ignored. .. For example, by setting the elasticity of the first connection portion CN1 to be different from the elasticity of the second connection portion CN2, the first connection portion CN1 can follow the movement at low speed drive (for example, frequency 60 Hz). However, it is not possible to follow the movement (micro vibration) at high speed drive (for example, frequency 30 kHz), and the second connection portion CN2 is used as the drive signal on the high speed drive side. It is conceivable that the torsion bar (spring for rotation) is made to function according to the rotational movement based on the vibration.

As described above, in the present embodiment, in the actuator 100, the coil portion 10 and the base portion 30 are connected and arranged by the first connecting portion CN1 so that the rotation centers are respectively arranged on the first axis AX1. Therefore, the problem of deformation of the base portion 30 due to the rotation of the coil portion 10 can be avoided. On top of this, by further providing a structure asymmetrical with respect to the first axis AX1 in the first connection portion CN1, the drive generated in the coil portion 10 is in a slightly unbalanced state with respect to the axial direction of the first axis AX1. Can be created. As a result, due to the rotational force around the first axis AX1 of the coil portion 10, the rotation of the driven portion 40 by the second connecting portion CN2 is not only around the first axis AX1 but also perpendicular to the first axis AX1. It is also possible to drive around the shaft AX2. That is, the driven portion 40 can be driven in two axes only by the rotational operation around one axis on the coil portion 10 side. Therefore, the structure for driving the coil portion 10 can be simplified, and the device can be made smaller, lighter, and power-saving as compared with the one in which the two-axis drive, which is one of the conventional configuration examples, is individually performed. be able to. Further, as for the magnetic field applying unit 20, since the applied magnetic field may be a simple one only in the Y-axis direction, the magnetic circuit is simplified and the magnetic field applying unit 20 and its peripheral mechanism can be miniaturized. Therefore, it is possible to reduce the size of the entire device. Further, since the magnetic flux density in the magnetic field applying portion 20 can be easily increased, the configuration can be configured with low power consumption.

Hereinafter, a modified example of the present embodiment will be described with reference to FIG. In the actuator 200 of this modification, the rotation drive source units have a pair configuration, that is, the first and second rotation drive source units DSa having a pair configuration arranged on the left and right of one operation unit RE as the rotation drive source unit DS. , DSb. This point is different from the actuator 100 illustrated in FIG. The rotation drive source units DSa and DSb are the coil unit 10 (10a, 10b), the magnetic field applying unit 20 (20a, 20b), and the first, which are the drive units, as in the rotation drive source unit DS in the case of FIG. It is composed of connection portions CN1 (CN1a, CN10b), respectively.

In the figure, the operation unit RE located at the center includes the first connection portion CN1a of the first rotation drive source unit DSa arranged on the right side (+ X side, one side) of the base portion 30 constituting the operation unit RE. It is connected to the first connection portion CN1b of the second rotation drive source portion DSb arranged on the left side (-X side, the other side) of the base portion 30, respectively. Further, each rotation drive source unit DSa and DSb are connected to the fixing portion 50 via a pair of rod-shaped connecting members CP and CP extending along the axis of the first axis AX1.

Further, as shown in the figure, each member constituting the first and second rotation drive source portions DSa and DSb has the center (the first axis AX1 and the second axis AX2) of the base portion 30 (or the driven portion 40). One side and the other side are arranged point-symmetrically with respect to the intersection point XX), and the first and second rotation drive source units DSa and DSb are controlled by the current I and the magnetic field so as to be driven in synchronization. The orientation of B is adjusted as appropriate. As a result, while providing the first connection portion CN1 (CN1a, CN1b) having a structure asymmetrical with respect to the first axis AX1, the symmetry of the actuator 200 as a whole is enhanced, and the stability of operation is improved. It is possible to suppress the bias of the load applied to the load.

[Second Embodiment]
Hereinafter, an example of the actuator according to the second embodiment will be described with reference to FIG. FIG. 3A is a block diagram for explaining an example of the actuator according to the present embodiment. The actuator according to the present embodiment is a modification of the actuator 100 of the first embodiment, and has common components except for the difference in how to provide an asymmetric structure. Therefore, the common components have the same reference numerals. , And detailed explanation is omitted.

As shown in FIG. 3A, the actuator 300 according to the present embodiment has an asymmetric structure in the coil portion 310 which is the drive portion of the rotary drive source portion DS, and is the first embodiment. It is different from the case of. Specifically, the coil portion 310 has a weight WG arranged by shifting the position of the center of gravity from the position of the first axis AX1. Further, the weight WG may be configured by making the weight balance of the reinforcing material or the like attached to the lower surface of the coil portion 310 which is the driving portion asymmetric. That is, in the coil unit 310 or the rotation drive source unit DS, the mass asymmetry is provided around the first axis AX1 along the X direction, and the position of the center of gravity is shifted from the center.

In the illustrated example, a pair of weights WG and WG are provided at positions of the coil portion 310 that are biased toward the + Y side from the position of the first axis AX1. In this case, as shown in FIG. 3B, the position of the center of gravity CTa of the coil portion 310 is shifted (shifted) to the + Y side with respect to the position of the center CT (connecting member CP) of rotation.

On the other hand, the first connection portion CN1 is arranged so as to extend in the X direction along the axis of the first axis AX1 without shifting. In this case, not only the connecting member CP but also the first connecting portion CN1 serves as the rotation center axis for the operation around the first axis AX1, and the rotation operation is stable.

Hereinafter, an example of the operation of rotationally driving the driven unit 40 in the actuator 300 will be described.

First, the operation around the first axis AX1 extending along the X direction will be described. The first connection portion CN1 is capable of following the rotational movement at low speed drive (60 Hz), that is, while maintaining a rigid body, the operation due to the rotational force received from the coil portion 10 is extended to the base portion 30. It is transmitted to the drive unit 40 to rotate them. That is, while the first connecting portion CN1 and the connecting member CP are used as torsion bars (springs for rotation), the driven portion 40 as a mirror rotates around the first axis AX1 extending along the X direction. Around the first axis AX1, the center of the rotational force coincides with the center of rotation of the first connecting portion CN1 and the connecting member CP as a torsion bar, so that stable operation is achieved.

Next, the operation around the second axis AX2 extending along the Y direction will be described. As described above, in the present embodiment, by providing the weight WG in the coil portion 310, as shown in FIG. 3B, the center of gravity CTa of the coil portion 310 is shifted from the central CT which is the rotation position. There is. As described above, since the center of gravity of the coil portion 310 and the center CT of rotation do not match, the coil portion 310 is subjected to slight vibration (rotational torque) around the second axis AX2 extending in the Y direction. Occurs in. Specifically, since the period of this micro-vibration (rotational torque) corresponds to the resonance frequency peculiar to the driven portion 40, the driven portion 40 is resonantly rotated around the second axis AX2. In other words, by adopting a frequency suitable for resonantly driving the driven unit 40 as a high-speed drive (for example, a frequency of 30 kHz), the driven unit 40 can be rotated around the second axis AX2. The drive signal on the high-speed drive side at this time has a value that is significantly different from the drive signal on the low-speed drive side, and the influence of the drive signal on the high-speed drive side on the operation on the low-speed drive side can be ignored. .. For example, by setting the elasticity of the first connection portion CN1 to be different from the elasticity of the second connection portion CN2, the first connection portion CN1 can follow the movement at low speed drive (for example, frequency 60 Hz). However, it is not possible to follow the movement (micro vibration) at high speed drive (for example, frequency 30 kHz), while the second connection portion CN2 is driven on the high speed drive side. It is conceivable that the torsion bar (spring for rotation) functions as a torsion bar following the rotational movement based on the signal.

Hereinafter, a modified example of the present embodiment will be described with reference to FIG. In the actuator 400 of this modification, the rotation drive source units have a pair configuration, that is, the actuator 400 has a pair of first and second rotation drive source units DSa and DSb arranged on the left and right sides of one operation unit RE. There is. This point is different from the actuator 200 illustrated in FIG. As with the rotary drive source section DS shown in FIG. 3, the rotary drive source sections DSa and DSb are the coil section 310 (310a, 310b), the magnetic field applying section 20 (20a, 20b), and the first connection, which are the drive sections. It is composed of parts CN1 (CN1a, CN1b), respectively.

Further, as shown in the figure, each member constituting the first and second rotation drive source portions DSa and DSb has the center (the first axis AX1 and the second axis AX2) of the base portion 30 (or the driven portion 40). One side and the other side are arranged point-symmetrically with respect to the intersection point XX), and the first and second rotation drive source units DSa and DSb are controlled by the current I and the magnetic field so as to be driven in synchronization. The orientation of B is adjusted as appropriate.

As described above, also in the present embodiment, in the actuator, the coil portion and the base portion are connected and arranged by the first connecting portion so that the rotation center is arranged on the first axis, respectively. It is possible to avoid the problem of deformation of the base part due to the rotation of the part. Further, by providing a weight in the coil portion as an asymmetrical structure with respect to the first axis, it is possible to create a slightly unbalanced state in the axial direction of the first axis for the drive generated in the coil portion. As a result, with respect to the rotation of the driven portion, a two-axis drive is performed in which the rotational force around the first axis of the coil portion drives not only around the first axis but also around the second axis perpendicular to the first axis. Can be done.

The present invention is not limited to the first and second embodiments described above, and can be carried out in various embodiments without departing from the gist thereof.

First, in the first and second embodiments, as an example of a configuration in which a structure asymmetrical with respect to the first axis is provided between the coil portion and the first connection portion, a coil or a coil that offsets the first connection portion. Although a weight is provided in the portion, a method other than the above may be adopted as long as an asymmetrical structure necessary for performing the two-axis drive can be provided. Further, the degree of shift, the position (arrangement) of the weight, the mass, the size, the shape, the number, and the like can be appropriately adjusted. Further, it is conceivable to provide a structure asymmetrical with respect to the first axis not only between the coil portion and the first connection portion but also in the base portion, for example.

Further, in the first embodiment, the first connection portion is offset, and in the second embodiment, the coil portion is provided with a weight. However, for example, a configuration in which these are combined can be considered.

Further, in the first and second embodiments, the shape of the base portion and the fixed portion is a frame shape, but the shape is not limited to this as long as the necessary functions such as support of the members can be maintained. Can be done.

Further, the control of the current I and the direction of the magnetic field B shown in the first and second embodiments are examples, and can be appropriately changed including the shape and arrangement of each part.

[Third Embodiment]
Hereinafter, an example of the actuator according to the third embodiment will be described with reference to FIG.

In order to perform two-axis drive in the driven portion of the actuator, for example, when two drive sources, one for low-speed drive and the other for high-speed drive, are provided as in the conventional case, the magnetic circuit may become large in size. There is. For example, if it is attempted to obtain ten driving forces on the high-speed drive side, it is conceivable that the magnetic circuit on the high-speed drive side of the two drive sources needs to be increased in size. This embodiment is based on the above, and as in each of the previous embodiments, while avoiding the problem of deformation of the base portion such as the frame that supports the driven portion such as the mirror, further. When providing an actuator capable of performing 2-axis drive of a driven unit with improved miniaturization, weight reduction, and power saving of the device, when two drive sources, one for low-speed drive and the other for high-speed drive, are provided. It is possible to suppress the increase in size of the drive source side of the magnetic circuit and the like in the above, and eventually to suppress the increase in size of the entire device.

FIG. 5A is a block diagram for explaining an example of the actuator according to the present embodiment. The actuator 500 as one embodiment of the present embodiment is an optical scanning device in a distance image device capable of acquiring distance image data about an object by scanning the object with pulsed light such as a laser pulse. It can be applied as a device for performing the above.

First, as shown in FIG. 5A, the actuator 500 according to the present embodiment has a pair of first and second rotation drive source units DSa and DSb that generate a force that is a drive source for rotation drive, and rotation drive. It is provided with an operating unit RE that receives a force from the source unit DS to perform a desired rotational operation, and a frame-shaped fixing unit 550 that fixes the entire device. Here, as an example, the first rotation drive source unit DSa mainly contributes to the rotation operation around the first axis AX1 extending along the X direction, and the rotation operation around the first axis AX1 is low speed. It is assumed that it is driven (for example, the frequency is 60 Hz). On the other hand, the second rotation drive source unit DSb contributes exclusively to the rotation operation around the second axis AX2 extending along the Y direction, and the rotation operation around the second axis AX2 is a high-speed drive (for example,). The frequency is 30 kHz).

Of the first and second rotation drive source units DSa and DSb, the first rotation drive source unit DSa located on the −X side of the operation unit RE is a coil unit 510a and a coil unit 510a, which are drive units that perform rotational operation. A magnetic field applying unit 520a that applies a magnetic field to the vehicle and a first connecting unit CN1a that connects the coil unit 510a to the operating unit RE side are provided.

Of the first and second rotation drive source units DSa and DSb, the second rotation drive source unit DSb located on the + X side of the operation unit RE is a coil unit that is a drive unit, like the first rotation drive source unit DSa. It includes 510b, a magnetic field applying portion 520b, and a first connecting portion CN1b. However, due to the difference in the direction of the magnetic field and the control of the flowing current, the arrangement of each part is different.

The operating portion RE is arranged inside the frame-shaped base portion (movable frame) 30 connected to the coil portions 510a and 510b via the first connecting portions CN1a and CN1b, respectively, and the frame-shaped base portion 30. It is provided with a driven portion 40 connected to the base portion 30 and a pair of second connecting portions CN2 and CN2 for connecting the base portion 30 and the driven portion 40.

Here, in FIG. 5A, the surface formed by the fixed portion 550, which is the outer frame, of the entire device shown in a plane is defined as a reference surface (horizontal plane), and the reference surface in FIG. 5A. The horizontal direction is the X direction, and the direction perpendicular to the X direction is the Y direction. The frame-shaped fixing portion 550 has a rectangular shape due to two sides extending in the X direction and two sides extending in the Y direction. Further, the direction perpendicular to both the X direction and the Y direction, that is, the direction perpendicular to the reference plane is defined as the Z direction.

With the above configuration, the actuator 500 transmits the exciting force generated on the first and second rotation drive source units DSa and DSb sides to the operating unit RE side having the driven unit 40, and the driven unit. The 40 is made rotatable with respect to two axes, a first axis AX1 extending along the X direction and a second axis AX2 extending along the Y direction perpendicular to the X direction.

Further, in the illustrated example, the first and second rotation drive source portions DSa and DSb are attached to the fixing portion 550 via a pair of rod-shaped connecting members CP and CP extending along the axis of the first axis AX1, respectively. It is connected. Further, it has a symmetrical shape with the first axis AX1 as the central axis, and can rotate about each axis in the direction indicated by the arrow R1 with the first axis AX1 as the axis (rotatable around the axis of the first axis AX1). ing. Further, the driven portion 40 is arranged inside the frame-shaped base portion 30, and is connected to the base via the second connecting portions CN2 and CN2, which are a pair of rod-shaped connecting members extending along the second axis AX2. It is connected to the unit 30. As a result, the driven unit 40 can rotate about the second axis AX2 in the direction indicated by the arrow R2. That is, the axis can be rotated around the axis of the second axis AX2.

A control current for rotating the driven unit 40 is supplied to the coil unit 10 from a power source (not shown). The control current is an alternating current including a signal component having a frequency corresponding to the drive frequency of the driven unit 40, and is as described above and conceptually shown in FIG. 5 (B). A first drive signal SG1 for low-speed drive (for example, frequency 60 Hz) and a second drive signal SG2 for high-speed drive (for example, frequency 30 kHz) are supplied to the vehicle. In particular, in the present embodiment, the first drive signal SG1 for low-speed drive is transmitted (applied) only to the coil unit 510a of the first rotation drive source unit DSa, but the second drive signal SG2 for high-speed drive is transmitted (applied). Is transmitted (applied) not only to the coil portion 510b of the second rotation drive source unit DSb but also to the coil portion 510a of the first rotation drive source unit DSa.

Here, the frequency of the first drive signal SG1 is non-resonant drive (forced drive) or resonance drive with respect to the natural frequency (resonance frequency) peculiar to the driven unit 40, and is the second. The frequency of the drive signal SG2 is resonant drive. By applying vibration by these drive signals, the actuator 500 drives the driven unit 40 to rotate.

Hereinafter, each part constituting the actuator 500 according to the present embodiment will be described more specifically.

First, the configuration of the first rotation drive source unit DSa will be described. Of the first rotation drive source unit DSa, the coil unit 510a has a loop-like structure in which windings made of a material having a relatively high conductivity such as gold or copper are provided along a rectangular frame. It has become. In particular, two of the four sides constituting the rectangular portion extend along the X direction and the current (alternating current) I flows in this direction, so that the direction of the magnetic field generated in the magnetic field applying portion 520a. It is designed to cross. As a result, the coil unit 510a receives the Lorentz force from the magnetic field applying unit 520a, and rotates about the axis at a runout angle and speed appropriately adjusted according to the scanning range, speed, and the like required by the driven unit 40. In particular, here, the coil portion 510a has a symmetrical shape with the first axis AX1 as the central axis, and the connection member CP connected to the fixed portion 550 and the first connecting portion CN1a connected to the base portion 30 are torsioned. Stable rotation operation as a bar (spring for rotation).

The magnetic field applying portion 520a is configured by, for example, combining a plurality of permanent magnets MG, MG, ..., And applies a magnetic field to the coil portion 510a. In the illustrated example, permanent magnets MG, MG, ... Are appropriately combined and installed to form the magnetic field applying portion 520a, and the magnetic field B is generated in the −Y direction. As described above, the coil portion 510a receives a force in the Z direction when the current I flows in the X direction orthogonal to the Y direction (Fleming's left-hand rule). That is, in the coil portion 510a, a force in the opposite direction, which is an equidistant couple extending along the X direction and is equidistant on the two sides, is generated in the ± Z direction. Therefore, the coil portion 510a rotates with the first axis AX1 extending along the X direction as the rotation center axis.

The first connection portion CN1a is an elastic member made of, for example, silicon, a copper alloy, an iron-based alloy, or another metal, or made of a resin. As shown in the figure, the first connection portion CN1a extends along the X direction on the first axis AX1 and connects the coil portions 510a arranged side by side in the X direction to the base portion 30. As described above, the first connection portion CN1a is arranged along the axis of the first axis AX1, and is also arranged along the axis of the first axis AX1 with respect to the operation around the first axis AX1. Together with the connecting member CP, it becomes the rotation center axis and stably rotates.

With the above configuration, the first rotational drive source unit DSa transmits the rotational drive force or rotational torque corresponding to the exciting force generated in the coil portion 510a to the base portion 30 via the first connection portion CN1a. do. In this case, the first connecting portion CN1a causes a vibrating action around the first axis AX1 with respect to the base portion 30. However, not only the first drive signal SG1 for performing the above-mentioned drive (low-speed drive) but also the second drive signal SG2 for high-speed drive is supplied to the coil portion 510a. (See Fig. 5 (B)).

Next, the configuration of the second rotation drive source unit DSb will be described. Of the second rotation drive source unit DSb, the coil unit 510b has a loop-like structure in which windings made of a material having a relatively high conductivity such as gold or copper are provided along a rectangular frame. It has become. In particular, two of the four sides constituting the rectangular portion extend along the Y direction, and the current (alternating current) I flows in this direction, so that the direction of the magnetic field generated in the magnetic field applying portion 520b. It is designed to cross. As a result, the coil unit 510b receives Lorentz force from the magnetic field applying unit 520b, and rotates about the axis at a runout angle and speed appropriately adjusted according to the scanning range, speed, and the like required by the driven unit 40.

The magnetic field applying portion 520b is configured by, for example, combining a plurality of permanent magnets MG, MG, ..., And applies a magnetic field to the coil portion 510b. In the illustrated example, permanent magnets MG, MG, ... Are appropriately combined and installed to form the magnetic field applying portion 520b, and the magnetic field B is generated in the −X direction. As described above, the coil portion 510b receives a force in the Z direction when the current I flows in the X direction orthogonal to the Y direction (Fleming's left-hand rule). That is, in the coil portion 510b, a force in the opposite direction, which is an equidistant couple on two sides extending along the Y direction, is generated in the ± Z direction. Therefore, the coil portion 510b rotates (slightly vibrates) in the direction of the arrow R3 with the third axis AX3, which is its own central axis extending along the Y direction, as the rotation center axis.

The first connection portion CN1b is an elastic member made of, for example, silicon, a copper alloy, an iron-based alloy, or another metal, or made of a resin. As shown in the figure, the first connection portion CN1b extends along the X direction on the first axis AX1 and connects the coil portions 510b and the base portion 30 arranged side by side in the X direction. The first connection portion CN1b is arranged along the axis of the first axis AX1. The coil portion 510b is connected to the fixing portion 550 by a connecting member CP arranged along the axis of the first axis AX1 like the first connecting portion CN1b.

With the above configuration, the second rotational drive source unit DSb transmits the rotational drive force or rotational torque corresponding to the exciting force generated in the coil portion 510b to the base portion 30 via the first connection portion CN1b. do. In this case, the first connecting portion CN1b causes a vibrating action around the second axis AX2 on the base portion 30. However, only the second drive signal SG2 for performing the above-mentioned drive (high-speed drive) is supplied to the coil portion 510b, and the first drive signal SG1 for low-speed drive is not supplied (FIG. 5 (B). )reference).

Finally, the configuration of the operating unit RE will be described. Of the moving portions RE, the base portion 30 has a symmetrical shape with the first axis AX1 as the central axis, and is a frame-shaped member having a driven portion 40 inside. Further, in the illustrated example, the base portion 30 is connected to the first connection portion CN1a of the first rotation drive source unit DSa on the −X side in the X direction, and the first connection of the second rotation drive source unit DSb on the + X side. It is connected to the portion CN1b. As a result, the base portion 30 receives (transmits) the rotational drive force or rotational torque corresponding to the exciting force generated in the coil portions 510a and 510b via the first connection portions CN1a and CN1b. However, the base portion 30 is a movable frame that is affected only by the coil portion 510a side with respect to the influence of its own rotation action, and rotates with the first axis AX1 as the rotation center axis. On the other hand, the base portion 30 transmits the rotational driving force or the rotational torque to the driven portion 40 via the second connecting portions CN2 and CN2 not only from the coil portion 510a side but also from the coil portion 510b side. Also convey things from. For example, by appropriately adjusting the elasticity of the first connection portions CN1a and CN1b, the first connection portion CN1a can follow the movement at low speed drive (for example, frequency 60 Hz). The first connection portions CN1a and CN1b cannot follow the movement (micro vibration) at high speed drive (for example, frequency 30 kHz), and transmit the second drive signal SG2 for high speed drive. On the other hand, for the second connection part CN2, the torsion bar (for rotation) follows the rotation operation based on the drive signal on the high-speed drive side. It is conceivable that it is designed to function as a spring).

The second connection portion CN2 is an elastic member, and as described above, is configured to be able to respond to vibrations at frequencies relatively higher than, for example, the first connection portions CN1a and CN1b. .. The second connecting portion CN2 is a pair of rod-shaped members extending along the second axis AX2, and is connected to each end of the driven portion 40 in the Y direction.

The driven portion 40 is a member having a flat surface portion (in the figure, an elliptical surface portion). For example, the flat surface portion or a part thereof is formed as a movable mirror surface (light reflecting surface), and the driven portion 40 is rotationally driven. By doing so, it becomes possible to perform optical scanning while inputting and reflecting light. As described above, the driven portion 40 is arranged inside the frame-shaped base portion 30 and is connected to the base portion 30 via the pair of second connecting portions CN2 and CN2.

Since the driven unit 40 is connected to the base unit 30, the driven unit 40 receives the rotational drive force or rotational torque from the coil unit 510a side based on the first drive signal SG1 for low-speed drive together with the base unit 30. The rotation operation is performed with the 1-axis AX1 as the rotation center axis. Further, the driven unit 40 receives a rotation drive force or a rotation torque from the coil unit 510b side based on the second drive signal SG2 for high-speed drive, and performs a rotation operation with the second axis AX2 as the rotation center axis. In the present embodiment, the second drive signal SG2 for high-speed drive is also transmitted to the coil unit 510a side constituting the first rotation drive source unit DSa for low-speed drive. As a result, the driven unit 40 is influenced by the first rotation drive source unit DSa and increases the swing angle on the high speed side without enlarging the configuration of the second rotation drive source unit DSb for high speed drive. Can be made to.

Hereinafter, an example of the operation of rotationally driving the driven unit 40 in the actuator 500 will be described. Here, as described above, the area around the first axis AX1 extending along the X direction is driven at low speed (for example, the frequency is 60 Hz), and the area around the second axis AX2 extending along the Y direction is driven at high speed. (For example, the frequency is 30 kHz). That is, here, the driven unit 40 is driven around the second axis AX2 by generating a vibration with a drive frequency higher than the vibration of the drive frequency corresponding to the rotational force around the first axis AX1. It has become. That is, in this case, the rotation of the driven unit 40 is driven not only around the first axis AX1 but also around the second axis AX2 perpendicular to the first axis AX1.

Regarding the control current supplied (applied) to the coil unit 510a for low-speed drive, the signal components of two frequencies corresponding to the drive frequency of the driven unit 40 (the drive signal on the low-speed drive side and the drive signal on the high-speed drive side). Both can be included. On the other hand, the control current supplied to the coil unit 510b for high-speed driving includes only the drive signal on the high-speed drive side among the two frequencies corresponding to the drive frequencies of the driven unit 40. As seen in FIG. 5B, the first drive signal SG1 which is the drive signal on the low speed drive side is transmitted only to the coil unit 510a, and the second drive signal SG2 which is the drive signal on the high speed drive side is the coil. It is transmitted to both the unit 510a and the coil unit 510b.

The second drive signal SG2 is generated as described above by appropriately adjusting the signals to be applied to the three leader lines L1, L2, and L3 for transmitting each drive signal shown in FIG. 5 (B). In addition to the mode of transmitting to both the coil unit 510a and the coil unit 510b, for example, the mode of transmitting the second drive signal SG2 only to the coil unit 510b, or the mode of transmitting the second drive signal SG2 without transmitting the first drive signal SG2. It is also possible to transmit SG1 only to the coil portion 510a.

As described above, in the present embodiment, the coil unit is a low-speed coil unit to which a low-speed drive signal (first drive signal SG1) for driving the driven unit 40 around the first axis AX1 is applied. It is provided with 510a and a coil unit 510b which is a high-speed coil unit to which a high-speed drive signal (second drive signal SG2) for driving the driven unit 40 around the second axis AX2 is applied, and is used for low speed. The coil portion 510a, which is a coil portion, can apply a high-speed drive signal (second drive signal SG2) in addition to the low-speed drive signal (first drive signal SG1). That is, in high-speed driving, by applying a high-speed drive signal to the low-speed coil in addition to the high-speed coil, not only the high-speed drive signal applied to the high-speed coil but also the high-speed drive applied to the low-speed coil is applied. Even the signal is slightly vibrated and transmitted to the driven unit 40, and the swing angle of the driven unit 40 on the high-speed side (around the second axis AX2) can be increased without adding a high-speed drive source. .. From a different point of view, it is possible to reduce the size of the device by avoiding the addition of drive sources.

Further, also in the present embodiment, in the actuator, the coil portion and the base portion are connected and arranged by the first connecting portion so that the rotation center is arranged on the first axis, thereby rotating the coil portion. It is possible to avoid the problem of deformation of the base portion due to the above.

The present invention is not limited to the above embodiment, and can be implemented in various embodiments without departing from the gist thereof.

First, in the above embodiment, the shape of the base portion and the fixed portion is a frame shape, but the shape is not limited to this as long as the necessary functions such as support of the member can be maintained, and various shapes can be used.

Further, the control of the current I and the direction of the magnetic field B shown in the above embodiment are examples and can be changed as appropriate.

Further, in the above embodiment, the drive unit is described as a coil unit, but any mechanism such as a piezoelectric element to which a drive force is applied may be used as the drive unit.

10,10a,10b ... Coil part, 20,20a, 20b ... Magnetic field applying part, 30 ... Base part, 40 ... Driven part, 50 ... Fixed part, 100,200,300,400,500 ... Actuator, 310,310a , 310b ... Coil part, 510a, 510b ... Coil part, 520a, 520b ... Magnetic field applying part, 550 ... Fixed part, AX1 ... 1st axis, AX2 ... 2nd axis, AX3 ... 3rd axis, B ... Magnetic field, CN1, CN1a, CN1b ... 1st connection part, CN2 ... connection part, CP ... connection member, CT ... center, CTa ... center of gravity, DS ... rotation drive source part, DSa ... first rotation drive source part, DSb ... second rotation drive source Unit, F, Fa ... force, I ... current, L1, L2, L3 ... leader wire, MG ... permanent magnet, R1, R2, R3 ... arrow, RE ... moving unit, SG1 ... first drive signal, SG2 ... second Drive signal, XX ... intersection

Claims (9)

The rotational operation part and the base part of the drive part are both arranged symmetrically with respect to the first axis with the rotation center on the first axis, and are connected by the first connection part.
Inside the base portion , the driven portion is connected by a second connecting portion extending in the direction of the second axis perpendicular to the first axis.
An actuator that is provided with a structure that is asymmetrical from the rotational operation portion to the first connection portion with respect to the first axis, and creates an unbalanced state with respect to the rotational drive of the first axis. The actuator according to claim 1, wherein the first connection portion is arranged offset from the position of the first axis. The center of the base portion is on the axis of the first axis.
The actuator according to claim 2, wherein the first connection portion is arranged offset with respect to the base portion. The actuator according to any one of claims 1 to 3, wherein the drive unit has a weight arranged by shifting the position of the center of gravity from the first axis. 1 The actuator according to any one of 4 to 4. The actuator according to any one of claims 1 to 5, wherein the drive unit and the base unit are connected to a fixed unit. Any one of claims 1 to 5, wherein the drive unit and the first connection unit have a pair configuration of one arranged on one side of the base portion and one arranged on the other side of the base portion. The actuator according to claim 1. The seventh aspect of claim 7, wherein one side and the other side of the paired drive unit and the first connection unit are arranged point-symmetrically with respect to the center of the base unit and are driven in synchronization with each other. Actuator. The rotary operation unit of the drive unit is a coil unit, and is a coil unit.
A magnetic field applying portion that applies a magnetic field to the coil portion is further provided.
The actuator according to any one of claims 1 to 8, wherein the magnetic field applying portion generates a magnetic field in one direction corresponding to a rotational force around the first axis generated in the coil portion.

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