JP2010051060A - Drive device and optical device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drive device capable of highly efficiently obtaining the characteristics of piezoelectric actuators; and to provide an optical device. <P>SOLUTION: The drive device for moving an image pickup optical system 2 includes: an actuator 8 for moving the image pickup optical system 2 in a yaw direction X; an actuator 6 for moving the image pickup optical system 2 in a pitch direction Y; a first control section 30 for driving the actuator 8 and the actuator 6 based on the characteristics of each of them; and the first control section 30 for obtaining the driving characteristics of each of the actuator 8 and the actuator 6. The first control section 30 simultaneously moves the image pickup optical system 2 in the yaw direction X and the pitch direction Y to obtain a moving speed, and obtains the driving characteristics based on the obtained moving speed, thereby highly efficiently obtaining the driving characteristics. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a driving device that drives an object and an optical device including the driving device.

  As a conventional drive device and optical device, one having an actuator (piezoelectric actuator) in which a drive shaft is attached to a piezoelectric element is known. For example, in Patent Documents 1 and 2, a piezoelectric element is expanded and contracted by a drive signal, a drive shaft is reciprocated according to an expansion and contraction operation of the piezoelectric element, and a driven member frictionally engaged with the drive shaft is moved. What moves an object is disclosed.

The drive device described in Patent Document 1 controls the moving speed of an object by controlling the application time to a piezoelectric element when driving is started, stopped, and reversed in driving direction. The drive device described in Patent Literature 2 stores a drive waveform in a memory in advance, selects a stored drive waveform according to a target movement direction and a target movement speed of an object, and controls the drive speed. is there.
JP-A-9-191676 JP 11-155292 A

  Here, in the drive device, the drive characteristics of the piezoelectric actuator change according to the use period and use frequency. For example, the friction coefficient between the drive shaft and the driven member may change depending on the use period and use frequency. For this reason, in the drive device described in Patent Document 1, it is difficult to move the object with high accuracy in accordance with the use period and the use frequency. Moreover, in the drive device described in Patent Document 2, it is necessary to predict drive characteristics in advance and store a large amount of drive waveforms, which may increase the resource load.

  Therefore, the present invention has been made to solve such a technical problem, and an object of the present invention is to provide a drive device and an optical device that can efficiently acquire the drive characteristics of a piezoelectric actuator.

  That is, the drive device according to the present invention is a drive device that moves an object, and moves the object in a second direction different from the first direction, and a first piezoelectric actuator that moves the object in the first direction. The second piezoelectric actuator to be driven, the drive control means for driving the first piezoelectric actuator and the second piezoelectric actuator based on the respective drive characteristics, and the drive for acquiring the respective drive characteristics of the first piezoelectric actuator and the second piezoelectric actuator Characteristic acquisition means, wherein the drive characteristic acquisition means is configured to acquire the movement speed by moving the object simultaneously in the first direction and the second direction, and acquire the drive characteristic based on the movement speed. Is done.

  When the drive device according to the present invention acquires the drive characteristics of the first and second piezoelectric actuators, the drive device simultaneously drives the first and second piezoelectric actuators in each of the first and second directions. Get the speed of movement. For this reason, since the moving speed can be acquired in a shorter time than when the first piezoelectric actuator and the second piezoelectric actuator are individually driven, the drive characteristics can be acquired efficiently.

  Here, in the drive device, it is preferable that the drive control means corrects the driving speed based on the drive characteristics. By doing so, the actuator can be driven at a speed corrected based on the drive characteristics, and thus control according to the control target is possible.

  In the driving device, the drive characteristic acquisition means sets the first reference position and the second reference position in a direction equally dividing the angle defined by the first direction and the second direction, and the drive control means sets the first piezoelectric position. Before driving the actuator or the second piezoelectric actuator, it is preferable to move the object in a section defined by the first reference position and the second reference position.

  With this configuration, it is possible to easily calculate the moving speeds in the first direction and the second direction, so that the driving speed can be acquired efficiently by acquiring the moving speed by a simple calculation.

  In the drive device, the drive characteristic acquisition means sets a plurality of reference positions in a direction equally dividing the angle defined by the first direction and the second direction, and the drive control means sets the first piezoelectric actuator or the second piezoelectric element. Before driving the actuator, it is preferable to move the object between the reference positions to acquire drive characteristics for each reference position and to correct the speed for each reference position. With this configuration, it is possible to improve the drive characteristic correction accuracy.

  Furthermore, the optical device according to the present invention includes the drive device described above. According to this optical device, since the drive device described above is provided, the drive characteristics of the optical member can be obtained efficiently.

  According to the present invention, drive characteristics of a piezoelectric actuator can be acquired efficiently.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and redundant description is omitted.

(First embodiment)
The imaging apparatus (optical apparatus) according to the present embodiment performs camera shake correction by relatively moving, for example, an imaging optical system and an imaging element in a direction orthogonal to the optical axis direction. That is, the camera shake is corrected by moving the imaging optical system in accordance with the camera shake and changing the relative position with the image sensor. This imaging apparatus is applied to a camera that captures still images, a video camera that captures moving images, an imaging unit mounted on a mobile phone, and the like.

  First, the mechanical configuration of the imaging apparatus according to the present embodiment will be described. FIG. 1 is an exploded perspective view of an imaging unit and a camera shake correction mechanism in an imaging apparatus according to an embodiment of the present invention. As shown in FIG. 1, the imaging apparatus according to the present embodiment includes an imaging optical system (object) 2 and an imaging element 14 for acquiring an image of a subject. The imaging optical system 2 is an optical system that focuses light on the imaging device 14 and includes a photographic lens. The imaging optical system 2 is configured by accommodating a lens (not shown) in a holder 2a, for example. The imaging optical system 2 may be composed of a single lens or a lens group composed of a plurality of lenses.

  The imaging optical system 2 is attached to the second moving member 5 and is provided so as to be relatively movable with respect to the imaging element 14 in a direction orthogonal to the direction of the optical axis O (optical axis direction). The second moving member 5 is accommodated in the image sensor holder 13 that fixes the image sensor 14 and is supported by the sphere 4, thereby moving relative to the image sensor holder 13 and the image sensor 14 in a direction perpendicular to the optical axis direction. It is possible. For this reason, the imaging optical system 2 moves relative to the imaging element 14 in a direction orthogonal to the optical axis direction when the imaging optical system 2 moves together with the second moving member 5.

  At this time, it is preferable that the imaging optical system 2 is attached to the second moving member 5 so as to be movable in the optical axis direction. For example, the support shaft 3 directed in the optical axis direction is attached to the second moving member 5, and the imaging optical system 2 is attached to be movable along the support shaft 3. As the actuator 10 that moves the imaging optical system 2 in the optical axis direction, an actuator that includes a drive shaft 10b that reciprocates by expansion and contraction of the piezoelectric element 10a is used. The actuator 10 functions as a third actuator that moves the imaging optical system 2 in the optical axis direction. The piezoelectric element 10 a is attached to the second moving member 5, and the drive shaft 10 b is frictionally engaged with the imaging optical system 2. One end of the drive shaft 10b is in contact with the piezoelectric element 10a and is bonded using, for example, an adhesive. The drive shaft 10b is a long member, for example, a cylindrical member.

  As the friction engagement structure, for example, a structure in which the drive shaft 10b is pressed against the holder 2a of the imaging optical system 2 with a constant pressing force by a plate spring, and a constant friction force is generated when the drive shaft 10b moves. And By moving the drive shaft 10b so as to exceed this frictional force, the position of the imaging optical system 2 is maintained by inertia. On the other hand, when the drive shaft 10b moves in the reverse direction so as not to exceed the frictional force, the imaging optical system 2 also moves in the reverse direction. The imaging optical system 2 can be moved relative to the second moving member 5 by repeating such a reciprocating movement of the drive shaft 10b. An electric signal for making the extension speed and the contraction speed different from each other is input to the piezoelectric element 10a from a control unit (not shown). Thereby, the drive shaft 10b reciprocates at different speeds, and the movement control of the imaging optical system 2 can be performed.

  In this way, by attaching the imaging optical system 2 to the second moving member 5 so as to be movable in the optical axis direction, focusing is performed by moving only the imaging optical system 2 with respect to the second moving member 5 in the optical axis direction. be able to.

  The image pickup device 14 is an image pickup unit that converts an image formed by the image pickup optical system 2 into an electric signal, and is fixedly attached to the image pickup device holder 13. For example, a CCD sensor is used as the image sensor 14.

  The imaging apparatus according to the present embodiment includes a first actuator (first piezoelectric actuator) 8 and a second actuator (second piezoelectric actuator) 6. The first actuator 8 is an actuator that relatively moves the imaging optical system 2 and the imaging element 14 in the yaw direction (first direction) X orthogonal to the optical axis direction. As the first actuator 8, for example, an actuator having a drive shaft 8b that reciprocates by expansion and contraction of the piezoelectric element 8a is used. The drive shaft 8b is disposed toward the yaw direction X. The piezoelectric element 8a is attached to the image sensor holder 13 to which the image sensor 14 is fixed. The drive shaft 8 b is frictionally engaged with the first moving member 11. One end of the drive shaft 8b is in contact with the piezoelectric element 8a and is bonded using, for example, an adhesive. The drive shaft 8b is a long member, for example, a cylindrical member.

  As the friction engagement structure, for example, the drive shaft 8b is pressed against the first moving member 11 with a constant pressing force by a plate spring, and a constant friction force is generated when the drive shaft 8b moves. To do. When the drive shaft 8b moves so as to exceed this frictional force, the position of the first moving member 11 is maintained by inertia. On the other hand, when the drive shaft 8b moves in the reverse direction so as not to exceed the frictional force, the first moving member 11 also moves in the reverse direction. By repeating such a reciprocating movement of the drive shaft 8 b, the first moving member 11 can be moved along the yaw direction X with respect to the imaging element 14, and the imaging optical system 2 can be moved relative to the imaging element 14. It can be moved in the yaw direction X. The piezoelectric element 8a receives an electrical signal from the control unit (not shown) that makes its expansion speed and contraction speed different. Thereby, the drive shaft 8b can reciprocate at different speeds, and the movement control of the imaging optical system 2 can be performed.

  The first actuator 8 may be configured by attaching the piezoelectric element 8 a to the first moving member 11 and frictionally engaging the drive shaft 8 b with the imaging element holder 13.

  The second actuator 6 is an actuator that relatively moves the imaging optical system 2 and the imaging element 14 in a pitch direction (second direction) Y orthogonal to the optical axis direction. The second actuator 6 and the first actuator 8 function as a driving unit that relatively moves the imaging optical system 2 and the imaging element 14.

  The pitch direction Y is set to a direction orthogonal to the optical axis direction and intersecting the yaw direction X. As the second actuator 6, for example, an actuator having a drive shaft 6b that reciprocates by expansion and contraction of the piezoelectric element 6a is used. The drive shaft 6b is arranged in the pitch direction Y. The piezoelectric element 6 a is attached to the second moving member 5. The drive shaft 6 b is frictionally engaged with the first moving member 11. One end of the drive shaft 6b is in contact with the piezoelectric element 6a and is bonded using, for example, an adhesive. The drive shaft 6b is a long member, and for example, a cylindrical member is used.

  As the friction engagement structure, for example, the drive shaft 6b is pressed against the first moving member 11 with a constant pressing force by a leaf spring, and a constant friction force is generated when the drive shaft 6b moves. To do. When the drive shaft 6b moves in one direction so as to exceed this frictional force, the position of the second moving member 5 is maintained by inertia. On the other hand, when the drive shaft 6b tries to move in the opposite direction so as not to exceed the frictional force, the second moving member 5 moves in one direction while the drive shaft 6b remains stationary by the frictional force. By repeating such reciprocating movement of the drive shaft 6b, the second moving member 5 can be moved along the pitch direction Y with respect to the image pickup device 14, and the image pickup optical system 2 can be moved relative to the image pickup device 14. It can be moved in the pitch direction Y. The piezoelectric element 6a receives an electrical signal from the control unit (not shown) that makes the extension speed and the contraction speed different. Thereby, the drive shaft 6b reciprocates at different speeds, and the movement control of the imaging optical system 2 can be performed.

  The second actuator 6 is attached to the first moving member 11 by the friction engagement described above. For this reason, when the 1st moving member 11 moves to the yaw direction X by the action | operation of the 1st actuator 8, the 2nd actuator 6 will also move to the yaw direction X.

  The second actuator 6 may be configured by attaching the piezoelectric element 6 a to the first moving member 11 side and frictionally engaging the drive shaft 6 b with the second moving member 5.

  The imaging device is provided with a position detection magnet 9 and Hall elements 15a and 15b. The position detection magnet 9 is a magnet attached to the second moving member 5 and is sufficient if it generates a magnetic field that can be detected by the Hall elements 15a and 15b. The Hall elements 15a and 15b are magnetic sensors that detect the relative positions of the imaging element 14 and the imaging optical system 2 with respect to the direction orthogonal to the optical axis direction based on the state of the magnetic field generated from the position detection magnet 9. For example, Attached to the substrate 17. As the Hall elements 15a and 15b, those capable of detecting a relative position in a direction orthogonal to the optical axis direction are used. The board | substrate 17 is a wiring board attached to the image pick-up element holder 13, and is bent and used for L shape, for example. The lead wires of the piezoelectric elements 6a, 8a and 10a are attached to the substrate 17 respectively.

  A photo interrupter 16 is provided in the imaging apparatus. The photo interrupter 16 is a position detection sensor that detects the position of the imaging optical system 2. The photo interrupter 16 is attached to the substrate 17 and is disposed in the vicinity of the imaging optical system 2. The photo interrupter 16 includes a light emitting unit and a light receiving unit, and detects the position of the imaging optical system 2 in the optical axis direction through position detection of the moving piece 2b passing between the light emitting unit and the light receiving unit. The moving piece 2 b is a member that is formed in the holder 2 a of the imaging optical system 2 and moves together with the imaging optical system 2.

  The imaging apparatus includes an upper cover 1. The upper cover 1 is a cover that covers the opening of the image sensor holder 13 that houses the image pickup unit and the camera shake correction mechanism, and forms an opening 1a for entering a subject image.

  The first moving member 11 is supported by the first support shaft 12 so as to be movable along the yaw direction X. The first support shaft 12 is a shaft member disposed in the yaw direction X, and is attached to the image sensor holder 13. The first support shaft 12 is provided through the bearing portion 11 a of the first moving member 11. Thus, the first moving member 11 is supported by the first support shaft 12 so as to move only in the yaw direction X with respect to the imaging element 14.

  The second moving member 5 is supported by the second support shaft 7 so as to be movable along the pitch direction Y. The second support shaft 7 is a shaft member arranged in the pitch direction Y and is attached to the second moving member 5. The second support shaft 7 is provided through the bearing portion 11 b of the first moving member 11. Thus, the second moving member 5 is supported by the second support shaft 7 so as to move only in the pitch direction Y with respect to the first moving member 11.

  Next, the electrical configuration of the imaging apparatus according to the present embodiment will be described. FIG. 2 is a block diagram illustrating an electrical configuration of the imaging apparatus according to the present embodiment. As shown in FIG. 2, the imaging apparatus according to the present embodiment includes a first control unit (drive control unit, drive characteristic acquisition unit) 30, and includes a first actuator 8, a second actuator 6, and a first control unit. The drive device is constituted by 30.

  For example, the first control unit 30 has a function of correcting the camera shake by controlling the relative movement of the imaging optical system 2 and the imaging element 14 in the direction orthogonal to the optical axis direction. The first control unit 30 has a function of, for example, driving the first actuator 8 and the second actuator 6 before the camera shake correction operation and acquiring the respective drive characteristics. And based on the acquired drive characteristic, it has the function to output the drive signal which drives the 1st actuator 8 and the 2nd actuator 6, respectively.

  The first control unit 30 is constituted by, for example, a CPU, an LSI (LargeScale Integration) incorporating a driver chip, and the like. The gyro sensor 50 connected to the first control unit 30 functions as a camera shake detection sensor that detects the amount of camera shake. The gyro sensor 50 is disposed outside the image stabilization unit, that is, outside the image sensor holder 13.

  Further, the first control unit 30 inputs the detection signal S1x of the gyro sensor 50 and the detection signal S2x of the hall element 15a, and outputs a drive signal Sx to the first actuator 8. The detection signal S1x of the gyro sensor 50 is a detection signal related to the amount of camera shake in the yaw direction X (X direction). The detection signal S2x of the hall element 15a is a detection signal related to the relative position of the imaging element 14 and the imaging optical system 2 in the yaw direction X.

  Further, the first control unit 30 inputs the detection signal S1y of the gyro sensor 50 and the detection signal S2y of the hall element 15b, and outputs the drive signal Sy to the second actuator 6. The detection signal S1y of the gyro sensor 50 is a detection signal related to the amount of camera shake in the pitch direction Y (Y direction). The detection signal S2y of the hall element 15b is a detection signal related to the relative position between the imaging element 14 and the imaging optical system 2 in the pitch direction Y.

  The second control unit 40 connected to the third actuator 10 functions as a control unit that controls movement of the imaging optical system 2 in the optical axis direction. The second control unit 40 is configured by, for example, an autofocus IC or a microcomputer. The second control unit 40 acquires distance information to the subject using a distance measuring device (not shown), outputs a drive signal to the actuator 10 based on the distance information and the detection signal of the photo interrupter 16, and moves the imaging optical system 2. Control.

  Next, a camera shake correction signal generation function of the first control unit 30 will be described. FIG. 3 is a schematic diagram of a camera shake correction circuit in the imaging apparatus according to the present embodiment. In the first control unit 30, for example, a camera shake correction circuit using a differential amplifier 31 shown in FIG. 3 is provided. This camera shake correction circuit is provided with two types, one that performs camera shake correction in the X direction and one that performs camera shake correction in the Y direction. The camera shake correction circuit in the X direction generates a drive signal Sx for the first actuator 8 according to the difference between the detection signal S1x of the gyro sensor 50 and the detection signal S2x of the Hall element 15a. The camera shake correction circuit in the Y direction generates a drive signal Sy for the second actuator 6 according to the difference between the detection signal S1y of the gyro sensor 50 and the detection signal S2y of the hall element 15b. As a result, the camera shake correction is performed by reducing the difference between the camera shake amount and the relative movement amount of the imaging optical system 2 and the image sensor 14.

  The detection signals S1x and S1y of the gyro sensor 50 are preferably integrated by the integration circuit 32 and input to the differential amplifier 31. The detection signals S2x and S2y of the Hall elements 15a and 15b are preferably input to the differential amplifier 31 after being amplified by the amplifier circuit 33.

  Next, details of signals output from the first control unit 30 to the first actuator 8 and the second actuator 6 will be described. FIG. 4 shows an example of signal waveforms input to the first actuator 8 and the second actuator 6, and the horizontal axis is time.

4A and 4B are signals when the first actuator 8 and the second actuator 6 are driven. That is, FIG. 4A shows output signals A _OUT and B _OUT (forward rotation signals) that are output when the frictionally engaged member is moved in a direction to approach the piezoelectric elements 6a and 8a. FIG. 4B shows A _OUT and B _OUT (signals during reverse rotation) that are output when the frictionally engaged member is moved in a direction away from the piezoelectric elements 6a and 8a.

4A and 4B, the two pulse signals A _OUT and B _OUT are signals input to two terminals (see FIG. 1) attached to the piezoelectric elements 6a and 8a, respectively. It is a signal constituting the drive signals Sx and Sy described above. These two pulse signals have, for example, the same frequency f (period T), and by making their phases different from each other, the potential difference between the two signals changes stepwise in one direction and suddenly in the opposite direction. A signal that changes or a potential difference between the signals changes suddenly in one direction and changes stepwise in the opposite direction. When the potential difference fluctuates, the piezoelectric elements 6a and 8a expand and contract. By continuously inputting signals for each pulse to the first actuator 8 and the second actuator 6, continuous driving is performed.

The pulse signals A _OUT and B _OUT are set so that, for example, one signal becomes a Hi output and drops to a Lo output, and then the other signal becomes a Hi output. Among these signals, when one signal becomes Lo output, the other signal is set to Hi output after a certain time lag tOFF has elapsed. OFF is an OFF output (open output).

The pulse signals A _OUT and B _OUT , that is, electric signals for operating the piezoelectric elements 6a and 8a are signals having a frequency exceeding the audible frequency. The frequency f of the two pulse signals A _OUT and B _OUT is a frequency signal exceeding the audible frequency, for example, a frequency signal of 30 to 80 kHz, and more preferably 40 to 60 kHz. By using a pulse signal having such a frequency, it is possible to reduce the operating sound in the audible region of the piezoelectric elements 6a and 8a.

  On the other hand, the signals when the first actuator 8 and the second actuator 6 are at rest are signals that are not shown, but the potential difference input to the two terminals attached to the piezoelectric elements 6a and 8a is zero. In addition, the input signal at rest in which the potential difference becomes zero is a signal in which the potential difference becomes zero in a long time that is longer than the cycle time of one pulse in the input signal at the time of driving shown in FIGS. 4 (A) and 4 (B). Is preferred.

  The signals input to the first actuator 8 and the second actuator 6 are not limited to those shown in FIG. 4, but may be sawtooth wave signals or triangular wave signals instead of pulse signals.

  Next, an operation at the time of camera shake correction in the imaging apparatus according to the present embodiment will be described. FIG. 5 is a flowchart illustrating an operation at the time of camera shake correction in the imaging apparatus according to the present embodiment. The control process shown in FIG. 5 is executed, for example, at a timing when camera shake occurs when shooting using the imaging device.

As illustrated in FIG. 5, the imaging apparatus starts from a process of starting the camera shake correction circuit of the first control unit 30 (S10). When the camera shake correction circuit is activated, the gyro sensor 50 detects the camera shake amount and outputs a camera shake detection signal S1 to the first control unit 30. Then, based on the detection signal S1 of the gyro sensor 50 and the detection signal S2 of the Hall elements 15a and 15b, the first control unit 30 prevents an image picked up by the image pickup element 14 using the camera shake correction circuit. The output signals Sx and Sy are calculated. Based on the output signals Sx and Sy, drive signals A _OUT and B _OUT to be output to the first actuator 8 and the second actuator 6 are generated. When the process of S10 ends, the process proceeds to a speed reading process (S12).

  The process of S12 is a process of reading the moving speed of the imaging optical system 2 by driving the first actuator 8 and the second actuator 6. This process will be described in detail with reference to FIGS. FIG. 6 is a flowchart showing the speed reading operation of the first control unit 30. FIG. 7 is a schematic diagram showing the movement position transition of the imaging optical system 2 as viewed from the optical axis O direction. The horizontal axis indicates the yaw axis indicating the position in the yaw direction X, and the vertical axis indicates the pitch axis indicating the position in the pitch direction Y. It has become. Each axis indicates a range of −1.5 ° to + 1.5 °. The position where both the yaw axis and pitch axis are 0 is the origin. Here, it is assumed that the origin overlaps with the optical axis O and is the movement start position of the imaging optical system 2. In addition, the reference position (first reference position) P1 and the reference position (second reference position) P2 are set so as to sandwich the origin in the 45 ° direction that equally divides the angle 90 ° defined by the yaw axis and the pitch axis. It is assumed that Here, it is assumed that the reference positions P1 and P2 are set to the maximum values (± 1.5 °) of the yaw axis and the pitch axis.

  As shown in FIG. 6, the first control unit 30 first moves the imaging optical system 2 from the origin to the reference position P1 (S20). This reference position P1 becomes the speed reading start position.

  The first control unit 30 causes the imaging optical system 2 to reach the reference position P1, and then moves the imaging optical system 2 from the reference position P1 to the origin (S22). The first control unit 30 outputs, for example, a drive signal for speed reading to the first actuator 8 and the second actuator 6, respectively, and drives the first actuator 8 and the second actuator 6 to move the imaging optical system 2 to the reference position P1. Move from to the origin. As the driving signal for reading the speed, for example, a signal having a constant frequency and a continuous pulse signal is used. As shown in FIG. 7, the first control unit 30 moves the imaging optical system 2 in the 45 ° direction and stops it at the origin.

The first control unit 30 detects the moving speed V1 of the imaging optical system 2 after stopping the imaging optical system 2 at the origin (S24). For example, the first control unit 30 measures the movement time from the reference position P1 to the origin, calculates the movement speed V1 from the reference position P1 to the origin, and moves in the pitch direction Y in the range of + 1.5 ° to 0 °. The moving speed V1 _{P at Y,} and the moving speed V1 _Y at the moving range + 1.5 ° to 0 ° in the yaw direction X are calculated.

  After calculating the moving speed V1, the first control unit 30 moves the imaging optical system 2 from the origin to the reference position P2 (S26). Similar to the processing of S22, the first actuator 8 and the second actuator 6 are driven using the driving signal for speed reading, and the imaging optical system 2 is moved to the reference position P2 in the 45 ° direction. And it stops at the reference position P2 (S28).

The first control unit 30 stops the imaging optical system 2 at the reference position P2, and then detects the moving speed V2 of the imaging optical system 2 (S30). For example, the first control unit 30 measures the movement time from the origin to the reference position P2, calculates the movement speed V2 from the origin to the reference position P2, and moves in the pitch direction Y from 0 ° to −1.5. moving speed V2 _P in °, calculates the moving speed V2 _Y in movement range 0 ° ~-1.5 ° in the yaw direction X.

  After calculating the moving speed V2, the first control unit 30 moves the imaging optical system 2 from the reference position P2 to the origin (S32). Similar to the processing of S22, the first actuator 8 and the second actuator 6 are driven using the driving signal for speed reading, and the imaging optical system 2 is moved to the origin in the 45 ° direction. And it stops at the origin (S34).

The first control unit 30 detects the moving speed V3 of the imaging optical system 2 after stopping the imaging optical system 2 at the origin (S36). For example, the first control unit 30 measures the movement time from the reference position P2 to the origin, calculates the movement speed from the reference position P2 to the origin, and moves in the pitch direction Y from −1.5 ° to 0 °. moving speed V3 _P, and calculates the moving speed V3 _Y in the moving range -1.5 ° ~0 ° in the yaw direction X in.

  After calculating the moving speed V3, the first control unit 30 moves the imaging optical system 2 from the origin to the reference position P1 (S38). Similar to the processing of S22, the first actuator 8 and the second actuator 6 are driven using the driving signal for speed reading, and the imaging optical system 2 is moved to the reference position P1 in the 45 ° direction. Then, it is stopped at the reference position P1 (S40).

The first control unit 30 stops the imaging optical system 2 at the reference position P1, and then detects the moving speed V4 of the imaging optical system 2 (S40). For example, the first control unit 30 measures the movement time from the origin to the reference position P1, calculates the movement speed V4 from the origin to the reference position P1, and moves in the pitch direction Y from 0 ° to + 1.5 °. The movement speed V4 _{P at Y} and the movement speed V4 _Y at the movement range 0 ° to + 1.5 ° in the yaw direction X are calculated.

When the process of S40 ends, the control process shown in FIG. 6 ends. By performing the control process shown in FIG. 6, the first control unit 30 moves the movement speeds V1 _P , V2 _P , V3 _P and V4 _{P in} the entire movement range in the pitch direction Y and the movement in the entire movement range in the yaw direction X. The speeds V1 _Y , V2 _Y , V3 _Y and V4 _Y can be calculated easily and quickly.

Returning to FIG. 5, when the process of S12 is completed, the routine proceeds to a speed correction process (S14). In the process of S14, the first control unit 30 corrects the drive signals A _OUT and B _OUT generated in the process of S10 based on the moving speed acquired in the process of S12. For example, when speed correction is performed for the second actuator 6 that moves the imaging optical system 2 in the pitch direction, the movement range in the pitch direction, the movement speeds V1 _P , V2 _P , V3 _P, and V4 _P and the drive signal for speed reading. Based on the number of drive pulses, the relationship (drive characteristics) between the movement range and the movement speed is calculated. Based on the calculated drive characteristics, the drive signals A _OUT and B _OUT output to the second actuator 6 are changed so that the moving speed of the imaging optical system 2 is constant within the moving range. Similarly, when speed correction is performed for the first actuator 8 that moves the imaging optical system 2 in the yaw direction, the movement range in the pitch direction, the movement speeds V1 _Y , V2 _Y , V3 _Y and V4 _Y, and driving for speed reading. Based on the number of drive pulses of the signal, the relationship (drive characteristics) between the movement range and the movement speed is calculated. Based on the calculated drive characteristics, the drive signals A _OUT and B _OUT output to the first actuator 8 are changed so that the moving speed of the imaging optical system 2 is constant within the moving range.

For example, the drive signals A _OUT and B _OUT are preferably changed by correcting the number of drive pulses per unit time. For example, the drive pulse before correction is a drive pulse shown in FIG. Here, assuming that the target speed in the pitch direction and the yaw direction is 3 mm / s, and the moving speed V1 _P calculated in S24 is 5 mm / s, the drive signal shown in FIG. By outputting a drive signal in which the drive period and the rest period are alternately continued, the number of pulses per unit time is changed so that the movement speed in the range of moving from the reference position P1 to the origin is the same as the target speed. To. Similarly, V2 _P , V3 _P , V4 _P , V1 _Y , V2 _Y , V3 _Y and V4 _Y are equal to the target speed by setting a pause period according to the difference between the target speed and the moving speed. Like that. Therefore, the accuracy of movement control of the imaging optical system 2 and the imaging element 14 is improved. The drive signals A _OUT and B _OUT are changed so that a continuous pulse signal (drive command) and a signal with a potential difference of 0 (pause command) are alternately output.

After changing the drive signal, the first control unit 30 outputs the changed drive signal to the first actuator 8 and the second actuator 6 to perform a camera shake correction operation (S16). The piezoelectric elements 6a and 8a expand and contract based on the input drive signals A _OUT and B _OUT , respectively, and the image pickup optical system 2 and the image pickup element 14 are relatively moved to perform camera shake correction. Thereby, even if camera shake occurs in the imaging apparatus, the imaging device 14 and the imaging optical system 2 are relatively moved and controlled, and the camera shake of the captured image of the imaging device 14 is suppressed.

  When the process of S16 ends, the control process shown in FIG. 5 ends. By performing the control process shown in FIG. 5, the drive characteristics of the first actuator 8 and the second actuator 6 can be easily acquired.

  As described above, according to the drive device and the optical device according to the first embodiment, when the drive characteristics of the first actuator 8 and the second actuator 6 are acquired, the first actuator 8 and the second actuator 6 are driven simultaneously, The movement speeds in the yaw direction and the pitch direction are acquired. Therefore, as shown in FIG. 12, the moving speed can be acquired in a shorter time compared to the case where the reference positions are provided in the yaw direction and the pitch direction and the first actuator 8 and the second actuator 6 are individually driven. Therefore, drive characteristics can be acquired efficiently. Then, by using the acquired drive characteristics to correct changes in the moving speeds of the first actuator 8 and the second actuator 6 due to changes over time, it is possible to perform a camera shake correction operation with high accuracy.

  Further, according to the driving device and the optical device according to the first embodiment, the imaging optical system 2 is moved in the 45 ° direction that equally divides the angle 90 ° defined by the pitch direction Y and the yaw direction. In addition, the movement speed in the yaw direction X can be easily calculated. Therefore, the driving speed can be efficiently acquired by acquiring the moving speed by a simple calculation. Since the actuator can be driven at a speed corrected based on the drive characteristics, control according to the control target is possible.

(Second Embodiment)
The drive device and the optical device according to the second embodiment are configured in the same manner as the drive device and the optical device according to the first embodiment, and read out the moving speed of the imaging optical system 2 (shown in FIG. 5). Only the processing of S12 is different. Therefore, in 2nd Embodiment, description is abbreviate | omitted in the part which overlaps with 1st Embodiment, and it demonstrates centering around difference.

  FIG. 9 is a flowchart showing the speed reading operation of the first control unit 30. FIG. 10 is a schematic diagram showing the movement position transition of the imaging optical system 2 viewed from the optical axis O direction, and is the same as the coordinate system shown in FIG. Further, the reference position P1 and the reference position P2 are set at the same positions as in the first embodiment.

  As shown in FIG. 9, the first control unit 30 first moves the imaging optical system 2 from the origin to the reference position P1 (S50). This reference position P1 becomes the speed reading start position.

  The first control unit 30 causes the imaging optical system 2 to reach the reference position P1, and then moves the imaging optical system 2 from the reference position P1 to the reference position P2 (S52). The first control unit 30 outputs, for example, a drive signal for speed reading to the first actuator 8 and the second actuator 6, respectively, and the first control unit 30 drives the first actuator 8 and the second actuator 6 to take imaging optics. The system 2 is moved from the reference position P1 to the reference position P2. As the driving signal for reading the speed, for example, a signal having a constant frequency and a continuous pulse signal is used. The first control unit 30 moves the imaging optical system 2 in the 45 ° direction as shown in FIG. 10 and stops it at the reference position P2 (S54).

The first control unit 30 stops the imaging optical system 2 at the reference position P2, and then detects the moving speed V5 of the imaging optical system 2 (S56). For example, the first control unit 30 measures the moving time from the reference position P1 to the reference position P2, calculates the moving speed V5 from the reference position P1 to the reference position P2, and moves the moving range in the pitch direction Y + 1.5. A moving speed V5 _{P at} a temperature of −1.5 ° and a moving speed V5 _Y at a moving range in the yaw direction X of + 1.5 ° to −1.5 ° are calculated.

  After calculating the moving speed V5, the first control unit 30 moves the imaging optical system 2 from the reference position P2 to the reference position P1 (S58). Similar to the processing of S52, the first actuator 8 and the second actuator 6 are driven using the driving signal for speed reading, and the imaging optical system 2 is moved in the 45 ° direction to the reference position P1. And it stops at the reference position P1 (S60).

The first control unit 30 stops the imaging optical system 2 at the reference position P1, and then detects the moving speed V6 of the imaging optical system 2 (S62). For example, the first control unit 30 measures the moving time from the reference position P2 to the reference position P1, calculates the moving speed V6 from the reference position P2 to the reference position P1, and moves the moving range in the pitch direction Y-1. A moving speed V6 _P at 5 ° to + 1.5 ° and a moving speed V6 _Y at a moving range of −1.5 ° to + 1.5 ° in the yaw direction X are calculated.

When the process of S62 ends, the control process shown in FIG. 9 ends. By performing the control processing shown in FIG. 9, the first control unit 30 moves the moving speeds V5 _P and V6 _{P in} the entire moving range in the pitch direction Y and moving speeds V5 _Y and V6 _{Y in} the entire moving range in the yaw direction X. Can be calculated easily and quickly.

  As described above, according to the driving device and the optical device according to the second embodiment, compared with the driving device and the optical device according to the first embodiment, the driving characteristics of the first actuator 8 and the second actuator 6 without stopping at the origin. Therefore, the movement speed can be acquired in a shorter time. Thereby, drive characteristics can be acquired more efficiently. Since the actuator can be driven at a speed corrected based on the drive characteristics, control according to the control target is possible.

  The above-described embodiment shows an example of the drive device and the optical device according to the present invention. The drive device and the optical device according to the present invention are not limited to the drive device and the optical device according to these embodiments, and the drive device and the optical device according to the embodiments are within the scope not changing the gist described in each claim. The device may be modified or applied to others.

  For example, in the above-described embodiment, an example in which two reference positions are set has been described. However, as illustrated in FIG. 11, a plurality of reference positions may be provided to obtain the movement speed. By providing a plurality of reference positions in this way, speed correction can be performed between the reference positions, so that the moving speed can be corrected with higher accuracy.

  In the above-described embodiment, the camera shake correction mechanism that moves the image pickup optical system 2 with respect to the image pickup device 14 according to camera shake has been described. However, the image pickup device 14 is moved with respect to the image pickup optical system 2. May be. In this case, the image sensor 1 becomes an optical member, and the same effect as the image pickup apparatus according to the above-described embodiment can be obtained.

  In the embodiment described above, the drive signal is changed by correcting the number of drive pulses per unit time. However, for example, the drive signal may be changed by correcting the drive frequency, duty ratio, and drive voltage. Good.

  In the above-described embodiment, the case where there are two actuators to be controlled by the first control unit 30 has been described. However, three or more actuators may be controlled. In the above-described embodiment, an example of adopting the camera shake correction mechanism has been described. However, the zoom mechanism and the autofocus mechanism may be used when driven by two or more actuators. For example, as shown in FIG. 13, the image pickup device can be driven in the direction orthogonal to the optical axis direction by the first actuator 8 and the second actuator 6, and the actuator can be driven in the optical axis direction by the actuator. The moving lenses 102 and 103 can be applied to an image pickup apparatus configured such that the image pickup device can be driven by the first actuator 8 and the second actuator 6. For example, a bending optical system that bends the optical axis O is applied to the imaging apparatus, and includes a fixed lens 105, a prism 104, moving lenses 103 and 102, a fixed lens 101, and an imaging element 100. When the actuator is driven, the moving lenses 103 and 102 are moved to realize a zoom function and an autofocus function. When the first actuator 8 and the second actuator 6 are driven, the image pickup element is moved and the camera shake is caused. A correction function is realized. An image of the subject 106 incident from the fixed lens 105 is bent through the prism 104 and detected by the image sensor 100 through the moving lens 103, the moving lens 102, and the fixed lens 101. In the imaging apparatus having such a zoom function, an autofocus function, and a camera shake correction function, it is possible to correct the speed based on the drive characteristics of the actuator by performing the control processing shown in FIGS.

  Furthermore, in the above-described embodiment, the actuator using the piezoelectric element is used as the actuator of the driving device and the optical device, but other driving parts such as a motor, a polymer actuator, a shape memory alloy may be used. .

FIG. 2 is an exploded perspective view of an imaging unit and a camera shake correction mechanism in the imaging apparatus according to the first embodiment of the present invention. 1 is a block diagram illustrating an electrical configuration of an imaging apparatus according to a first embodiment. FIG. 3 is a schematic diagram of a camera shake correction circuit included in the first control unit illustrated in FIG. 2. It is a drive signal which the 1st control part shown in Drawing 2 outputs. 3 is a flowchart illustrating a camera shake correction operation of the imaging apparatus according to the first embodiment. 3 is a flowchart illustrating a speed reading operation of the imaging apparatus according to the first embodiment. It is a schematic diagram explaining the speed reading operation | movement shown in FIG. It is a figure explaining the outline | summary of the drive signal of the drive device which concerns on embodiment of this invention. It is a flowchart which shows the speed reading operation | movement of the imaging device which concerns on 2nd Embodiment. FIG. 10 is a schematic diagram illustrating a speed reading operation illustrated in FIG. 9. It is a schematic diagram explaining another speed read-out operation. It is a schematic diagram explaining the conventional speed reading operation. It is a schematic diagram of the imaging optical system of the imaging device which employ | adopted the drive device which concerns on embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 2 ... Imaging optical system (object, optical member), 6 ... Actuator (2nd piezoelectric actuator), 8 ... Actuator (1st piezoelectric actuator), 30 ... 1st control part (a drive control means, a drive characteristic acquisition means).

Claims (5)

A drive device for moving an object,
A first piezoelectric actuator for moving the object in a first direction;
A second piezoelectric actuator for moving the object in a second direction different from the first direction;
Drive characteristic acquisition means for acquiring respective drive characteristics of the first piezoelectric actuator and the second piezoelectric actuator;
Drive control means for driving the first piezoelectric actuator and the second piezoelectric actuator based on the drive characteristics;
With
The drive characteristic acquisition means acquires the moving speed by moving the object simultaneously in the first direction and the second direction, and acquires the driving characteristic based on the moving speed;
A drive device characterized by   The driving apparatus according to claim 1, wherein the driving control unit corrects a driving speed based on the driving characteristics. The drive characteristic acquisition means sets the first reference position and the second reference position in a direction equally dividing an angle defined by the first direction and the second direction;
Moving the object in a section defined by the first reference position and the second reference position before the drive control means drives the first piezoelectric actuator or the second piezoelectric actuator;
The drive device according to claim 1, wherein: The drive characteristic acquisition means sets a plurality of reference positions in a direction equally dividing an angle defined by the first direction and the second direction;
Before the drive control means drives the first piezoelectric actuator or the second piezoelectric actuator, the drive object is moved between the reference positions to acquire the drive characteristics between the reference positions, and the reference position The drive device according to claim 1, wherein the speed is corrected every interval. A drive device according to any one of claims 1 to 4, comprising:
The optical device is characterized in that the object is an optical member.

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