JP4682699B2 - Driving apparatus and driving method - Google Patents

Description

  The present invention relates to a driving technique for driving a movable part using a plurality of actuators connected to the movable part from different directions.

  A shape memory alloy (hereinafter also referred to as “SMA”) stores a memorized shape when it is heated to a temperature equal to or higher than the reverse transformation end temperature even when subjected to an external force at a temperature equal to or lower than the martensitic transformation start temperature and plastically deformed ( (Memory shape). A technique has been proposed in which SMA having such characteristics is used as an actuator for camera shake correction of an imaging unit (for example, Patent Document 1).

  Since camera shake correction requires high-speed responsiveness of the actuator, when adopting an actuator using SMA (hereinafter also referred to as “SMA actuator”), for example, two SMAs in a push-pull arrangement with respect to the imaging unit. It is preferable to connect an actuator. The responsiveness can be further improved by energizing each of the two SMA actuators to perform coordinated servo control.

JP 2001-273035 A

  However, if the two SMA actuators are only servo-controlled in a coordinated manner as described above, an unnecessary camera shake correction operation is performed when the user pans, for example, at the time of zero method camera shake correction. There is a problem of giving a sense of incongruity. In such a case, if the two SMA actuators are controlled independently, the above problem may be solved.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a driving technique capable of appropriately switching between cooperative control and independent control for a plurality of SMA actuators connected to a movable part.

In order to solve the above-mentioned problems, the invention of claim 1 is a drive device capable of driving the movable part using two actuators connected to the movable part from different directions, and (a) Measuring means for obtaining measurement values relating to driving of the movable part; and (b) control means for controlling driving of the movable part, each of the two actuators having a shape memory alloy, and the shape memory alloy Functioning as an actuator that drives the movable part by a resultant force when contraction force generated by energizing the movable part acts on the movable part from the different directions, and the control means (b-1) the contractile force reducing cooperatively deviation of the said measured value and the driving target value relating to driving of the movable portion so that the two actuators are generated respectively, said two actuating Transformation temperature in the region of the shape memory alloy in each of the shape memory alloy, the cooperative control means cooperatively controls the two actuators current based on the deviation by energizing respectively, to (b-2) the deviation A first independent control that holds the movable part at a specific position by deriving in advance and energizing each of the two actuators with a current that causes the contraction force based on the drive target value to be generated in advance. the current supplied to the one actuator to zero, selectively executing a second independent control for generating a contraction force to move the movable portion in one direction by passing a predetermined current to the other actuator An independent control means; and (b-3) a selection means for selectively executing cooperative control by the cooperative control means and independent control by the independent control means. That.

Further, the invention of claim 2, in the driving device according to the invention of claim 1, which enables image stabilization according to the image pickup means having a movable portion by the two actuators, said selection means, said When the camera shake correction is performed, the cooperative control is executed, and when the camera shake correction is not performed, the independent control is executed.

According to a third aspect of the present invention, in the driving apparatus according to the first or second aspect of the present invention , the selection means executes the second independent control when detecting the movable limit of the movable portion. Have

According to a fourth aspect of the present invention, there is provided the driving device according to any one of the first to third aspects, wherein the selection means is configured to perform the second when the driving performance relating to each of the two actuators is inspected . Means for executing independent control;

According to a fifth aspect of the present invention, in the drive device according to any one of the first to fourth aspects of the present invention, a reference position is determined for driving the movable portion, and the selection means selects the movable portion. Means for executing the first independent control in the case of holding the reference position.

According to a sixth aspect of the present invention, in the drive device according to the first aspect of the present invention, camera shake correction relating to the imaging means having the movable part can be performed by the two actuators, and the selection means When the camera shake correction is performed, the first independent control is executed when panning related to the imaging unit is performed, and the cooperative control is executed when panning is not performed.

The invention according to claim 7 is a method for driving the movable part using two actuators connected to the movable part from different directions, and is a measurement for obtaining a measurement value related to the drive of the movable part. Each of the two actuators has a shape memory alloy, and the contraction force generated by energizing the shape memory alloy is from the different direction. While functioning as an actuator that drives the movable part by the resultant force when acting on each of the movable parts, the control step cooperates with a deviation related to the drive target value and the measurement value for driving the movable part. the two actuators of the contractile force reducing Te is to generate respectively, the two actuators each of the shape memory alloy in the shape memory Transformation temperature region of gold, and cooperative control step of cooperatively controlling the two actuators by energizing current based on the deviation, respectively, not based on the deviation, the contractive force based on the driving target value a first independent control for holding the movable part in a particular position, the current supplied to the one actuator to zero by the energizing each previously derived current to be generated in each of the two actuators, An independent control step of selectively executing a second independent control for generating a contraction force for moving the movable portion in one direction by passing a predetermined current through the other actuator ;
A selection step of selectively executing the cooperative control by the cooperative control step and the independent control by the independent control step.

In order to solve the above-described problems, according to the first to seventh aspects of the present invention, the shape memory alloy of each of the plurality of actuators is energized based on the deviation between the drive target value and the measurement value related to the driving of the movable part. Thus, it is possible to cooperatively control a plurality of actuators and to independently control each of the plurality of actuators without being based on the above-described deviation, and cooperative control and independent control are selectively executed. As a result, it is possible to appropriately switch between cooperative control and independent control for a plurality of SMA actuators.

According to the second aspect of the invention, the cooperative control is executed when the camera shake correction is performed, and the independent control is executed when the camera shake correction is not performed. It can be done at the timing.

In the invention of claim 3 , since the independent control is executed when the movable limit of the movable part is detected, the independent control can be performed at an appropriate timing.

In the invention of claim 4, the independent control is executed when the driving performance relating to each of the plurality of actuators is inspected, so that the independent control can be performed at an appropriate timing.

Further, in the invention of claim 5 , since the independent control is executed when the movable part is held at the reference position, the independent control can be performed at an appropriate timing.

Further, in the invention of claim 6 , in the case of camera shake correction, independent control is executed when panning related to the imaging means is performed, and cooperative control is executed when panning is not performed. Switching between control and independent control can be performed at an appropriate timing.

<First Embodiment>
<Key phone configuration>
FIG. 1 is a side view showing a mobile phone 1A incorporating a camera shake correction system 10A according to the first embodiment of the present invention. The cellular phone 1A has a communication function and an imaging function, and functions not only as a communication device but also as an imaging device.

  As shown in FIG. 1, the mobile phone 1A includes a display unit 71 configured with an LCD or the like and an input unit 72 configured with various keys on the main body surface. Further, in the broken portion of FIG. 1, the state inside the mobile phone 1A is shown. As shown in the broken portion or the like, the cellular phone 1A has a built-in camera shake correction system 10A that functions as a driving device.

  FIG. 2 is a diagram showing elements included in the camera shake correction system 10A in more detail. As shown in FIG. 2, the camera shake correction system 10A includes a substantially cylindrical imaging unit 9A, and a substantially cylindrical main body side member (also referred to as a casing side member) 12 having an inner diameter larger than the outer diameter of the imaging unit 9A. It has. 2 is a side view, the imaging unit 9A and the main body side member 12 are both shown in a rectangular parallelepiped shape in FIG. 2, but when viewed from the front side, the imaging unit 9A and the main body side member 12 are both It has a substantially circular shape.

  The imaging unit 9 </ b> A includes a photographic lens 3, a diaphragm 4, an imaging device 5, a focus actuator 6, a diaphragm actuator 7, and a shake detection sensor 8. The photographing lens 3, the diaphragm 4, the image sensor 5, the focus actuator 6, the diaphragm actuator 7, and the shake detection sensor 8 are all fixed to the imaging unit 9A. The photographing lens 3 is composed of one or a plurality of lenses. A light image (subject image) of the subject passing through the photographing lens 3 is formed on the image sensor 5. The image pickup device 5 has a fine pixel group to which a color filter is attached, and performs photoelectric conversion into an image signal having RGB color components, for example. As the image sensor 5, for example, a CCD or a CMOS is used. The focus actuator 6 can bring the subject into focus by moving the focus lens of the photographing lens 3, and the diaphragm actuator 7 drives the blades of the diaphragm 4 to drive the diaphragm 4. It is possible to adjust the condition. The shake detection sensor 8 is fixed to the imaging unit 9A, and detects the shake of the imaging unit 9A.

  The main body side member 12 includes a member 12a having a substantially cylindrical shape whose one end surface is open, a cover glass 12b provided so as to close the open surface of the member 12a, and the like. The main body side member 12 is a member fixed to the apparatus main body side of the mobile phone 1A. Specifically, the member 12a is fixed to the main body of the mobile phone. The cover glass 12b having translucency has a role of preventing foreign matter from entering the imaging unit 9A from the outside, and a role of transmitting a light image from the subject to the imaging element 5 through the photographing lens 3. And have.

  The camera shake correction system 10A further includes an elastic support member 11a having a substantially cylindrical shape. The elastic support member 11 a is provided between the imaging unit 9 </ b> A and the main body side member 12. One end face of the elastic support member 11a is fixed to the imaging unit 9A, and the other end face is fixed to the main body side member 12. Thus, the imaging unit 9A is basically fixed to the main body side member 12 by the elastic support member 11a.

  However, since the imaging unit 9A is supported by an elastic support member 11a having elasticity, when a driving force is applied by the driving unit 16 described later, the imaging unit 9A is 2 with the elastic support member 11a as a fulcrum. It is possible to move in a two-dimensional rotational motion, specifically in the rotational direction (pitch direction) around the X axis, and in the rotational direction (yaw direction) around the Y axis. That is, when a force larger than the holding force by the elastic support member 11a is applied as a driving force, the imaging unit 9A has a predetermined rotation axis (an axis parallel to the X axis and a parallel to the Y axis) with respect to the body side member 12. It is possible to swing around an axis.

  Therefore, as will be described later, even when the main body of the mobile phone 1A is shaken by hand shake or the like, the image pickup unit 9A is in a direction to cancel the shake detected by the shake detection sensor 8 (in other words, in the opposite direction to the detected shake). It is possible to correct camera shake by moving.

  As described above, the imaging unit 9A is fixed to the main body side member 12 when not driven by the drive unit 16 (described later), while the main body side member 12 is applied when the driving force by the drive unit 16 is applied. It is possible to move relative to. That is, the imaging unit 9A is supported (held) with an appropriate strength.

  In FIGS. 1 and 2, an XYZ orthogonal coordinate system is set. The X axis indicates the horizontal direction, the Y axis indicates the vertical direction, and the Z axis indicates a direction orthogonal to both the X axis and the Y axis. Hereinafter, description will be made with reference to this XYZ coordinate system as appropriate.

<Details of the drive system of the image stabilization system>
As shown in FIG. 2, the camera shake correction system 10A includes a drive unit 16 for driving the imaging unit 9A. Specifically, a P drive actuator 16P for driving the imaging unit 9A in the rotation direction (pitch direction) around the X axis and a Y drive for driving the imaging unit 9A in the rotation direction (yaw direction) around the Y axis. And an actuator 16Y (see FIG. 5). In other words, the P drive actuator 16P can rotate the imaging unit 9A in the pitch direction, and the Y drive actuator 16Y can rotate the imaging unit 9A in the yaw direction. By using the P / Y drive actuators 16P and 16Y to rotate in the pitch direction and the yaw direction, it is possible to correct the shaking of the imaging unit 9A, that is, to correct the camera shake. Thereby, as a hand shake, for example, a sine wave shake of about 1 to 10 Hz can be corrected.

  The P drive actuator 16P has a pair of drive members 15 (15a, 15b). These drive members 15a and 15b are formed as linear members using shape memory alloy (SMA), and have, for example, a current-displacement characteristic of SMA shown in FIG. That is, the SMA of the drive member 15 is heated to the austenite transformation start temperature when the energization current reaches the current value I1, and thus starts to deform in the contraction direction, and when the current value I2 heated to the transformation end temperature is reached, the deformation occurs. Complete.

  One end of each drive member 15a, 15b in the P drive actuator 16P is fixed to the upper part of the outer peripheral surface of the imaging unit 9A, and the other end is fixed to the upper inner surface of the main body side member 12. Then, as will be described later, each of the drive members 15a and 15b expands and contracts according to the amount of heat generated by current application, and drives the imaging unit 9A in the pitch direction.

  As described above, the drive members 15a and 15b fixed to both the main body side member 12 and the imaging unit 9A are provided on both ends of the imaging unit 9A in the pitch direction. That is, the imaging unit 9A can be driven by a plurality of driving members (actuators) 15a and 15b connected to the imaging unit (movable part) 9A from different directions.

  The Y drive actuator 16Y has the same configuration as the P drive actuator 16P. Although not shown in FIG. 2, in order to enable the imaging unit 9A to be driven in the yaw direction, the Y drive actuator 16Y has a pair of drive members 15c and 15d (not shown). These drive members 15c and 15d have the same configuration as the drive members 15a and 15b described above.

  Specifically, one end of the drive member 15 c is fixed to the left side of the outer peripheral surface of the imaging unit 9 </ b> A (front side on the paper surface), and the other end is fixed to the left inner surface of the main body side member 12. One end of the drive member 15d is fixed to the right side of the outer peripheral surface (back side of the paper) of the imaging unit 9A, and the other end is fixed to the right inner surface of the main body side member 12. As will be described later, these drive members 15c and 15d expand and contract in accordance with the amount of heat generated by current application, and drive the imaging unit 9A in the yaw direction.

  Below, the drive principle about the P drive actuator 16P is demonstrated. Although omitted to avoid duplication of explanation, the same applies to the other Y drive actuator 16Y.

  FIG. 4 is a diagram showing the relationship between the applied current to the SMA and the displacement of the imaging unit 9A. In the following description, FIG. 5 is also referred to as appropriate.

  A relatively large current (for example, an upper limit value of applied current) is applied to the SMA (hereinafter also referred to as “SMAb”) of one drive member 15b, and current is supplied to the SMA (hereinafter also referred to as “SMAa”) of the other drive member 15a. Assume that no voltage is applied. In this case, the driving member 15b is heated and contracts, and the driving member 15a becomes a relatively low temperature and easily stretches. Therefore, the drive member 15a is extended by the contraction force of the drive member 15b (FIG. 5A).

  From this state, the current applied to the SMA of the drive member 15b is decreased and the current applied to the SMA of the drive member 15a is increased. As a result, the contraction force of the drive member 15a increases after the drive member 15b becomes relatively easy to extend, so that the imaging unit 9A is parallel to the main body side member 12 with a predetermined rotation axis (for example, parallel to the X axis). And gradually rotate counterclockwise around the center axis RX). At a certain point in time, the drive members 15a and 15b have the same length, and as shown in FIG. 5B, the imaging unit 9A has an optical axis AX of the photographing lens 3 that is parallel to the Z axis. Then, it moves to a reference position (center position) for driving the imaging unit 9A. Then, when the applied current to the SMA of the driving member 15a is further increased and the applied current of the driving member 15b is further decreased, the driving member 15a is further contracted and the driving member 15b is further expanded, as shown in FIG. In addition, the incident surface side of the imaging unit 9A is now inclined to the upper right.

  Conversely, from the state of FIG. 5C, when the applied current to the SMA of the driving member 15a is decreased and the applied current to the SMA of the driving member 15b is gradually increased, the imaging unit 9A becomes the main body side member 12. Is gradually rotated clockwise, and the state shown in FIG. 5B is changed to the state shown in FIG.

  Therefore, the imaging unit 9A can be driven in both the positive and negative directions of the pitch direction by controlling the magnitude of the applied current to the pair of driving members 15a and 15b formed of SMA.

  Even when such a drive system is used, the imaging unit 9A is moved with respect to the main body side member 12 in the direction to cancel the shaking detected by the shaking detection sensor 8 provided in the imaging unit 9A, as described above. By doing so, it is possible to correct camera shake related to the imaging unit (imaging means) 9A.

  Further, in order to increase the drivable range for camera shake correction, a predetermined current is applied at the time of photographing so that the imaging unit 9A exists at the center position (see FIG. 5B). Is preferred.

  As shown in FIG. 4, when there is hysteresis in the displacement operation of the imaging unit 9A by a pair of SMAs, an input voltage or the like that compensates for such hysteresis may be determined in the control system.

  FIG. 6 is a diagram showing an outline of a control system related to imaging processing and camera shake correction in the mobile phone 1A. As shown in FIG. 6, the shake detection sensor 8 provided in the imaging unit 9A supported by the elastic support portion 11a detects the shaking of the imaging unit 9A. Specifically, the shake detection sensor 8 includes a gyro sensor (P shake detection gyro) 8a for detecting an angular velocity (specifically, an inertial angular velocity (ground angular velocity)) of the imaging unit 9A in the pitch direction, and an imaging unit in the yaw direction. And a gyro sensor (Y shake detection gyro) 8b for detecting an angular velocity of 9A.

  Output signals from the respective gyros 8a and 8b of the shake detection sensor 8 are input to the control unit 30a, amplified and filtered by the shake detection circuit 30d, and then used as signals indicating the “shake” of the imaging unit 9A. Detected and input to the digital control unit 30b.

  The digital control unit 30b is configured by a microcomputer and controls driving of the imaging unit (movable unit) 9A. By executing a predetermined software program in the microcomputer, each of the angle detection unit 31, the target angle setting unit 32, the current angle setting unit 33, the optimum control value calculation unit 34, and the control value output unit 35 is included. The function of the processing unit is realized. The angle detection unit 31, the target angle setting unit 32, the current angle setting unit 33, and the optimum control value calculation unit 34 constitute a zero method control unit 30c. The zero method control unit 30c is a control system that drives the imaging unit 9A so that the shake detected by the shake detection sensor 8 becomes zero.

  The release button 29 is configured as a two-stage push button. The digital control unit 30b starts AF processing and AE processing when the shutter button 29 is pushed down to a half-pressed state (also referred to as state S1). In addition, when the release button 29 is further pushed down to a fully depressed state (also referred to as state S2), the digital control unit 30b performs an exposure operation for taking a recording image. In addition, when the digital control unit 30b is in the fully-pressed state S2 (in response to a signal for detecting the fully-pressed state S2), the digital control unit 30b considers that the main photographing instruction has been input and inputs the start instruction for the camera shake correction control. The camera shake correction control, which will be described in detail later, is started. However, the present invention is not limited to this, and the camera shake correction control may be started in response to an input operation other than the release button 29. In addition, the camera shake correction control may be started not only at the time of inputting an instruction to start shooting, but also from the start instruction time of shooting preparation (time when the half-pressed state S1 is reached).

  The sequence control unit 36 controls a sequence such as a shooting operation or a camera shake correction operation using the imaging unit 9A. Specifically, when the release button 29 is not pressed, a live view image of the subject is displayed on the display unit 71 (LVON state). When the release button 29 is pressed halfway, preparation for shooting is started and AF operation and AE operation are performed (S1 ON state). On the other hand, when the release button 29 is fully pressed, the photographing lens 3 is brought into focus and the photographing lens 3 is focused, and a control signal is transmitted to the zero method control unit 30c to start a camera shake correction operation. In this camera shake correction operation, the sequence is controlled in the following order.

  (1) The angle detector 31d detects the angle (θp, θy) of the imaging unit 9A immediately after the start of the camera shake correction operation by fetching the angular velocity signal from the shake detection circuit 30d and performing a predetermined integration, and the target angle setting unit In 32, the target angle (θpd, θyd) is set.

  (2) After setting the target angle, the angle detection unit 31 sequentially detects the angle of the imaging unit 9A, and the current angle setting unit 33 sets the current angle (θp, θy).

  (3) The optimal control value is calculated by the optimal control value calculation unit 34 so that the current angle (θp, θy) becomes the target angle (θpd, θyd), and the drive unit 16 is driven via the control value output unit 35. .

  By the operations (1) to (3), the angle of the imaging unit 9A immediately after the start of the camera shake correction operation is held during the camera shake correction operation.

  The center instruction unit 37 is a part for holding the imaging unit 9A at the center position shown in FIG. 5C, and stores information on the applied voltages of the driving members 15a to 15d necessary for center holding at room temperature. Based on this information, the application voltage of each drive member is indicated (detailed later). As for the applied voltage information of each driving member, the applied voltage necessary for center holding differs depending on the state of the imaging unit 9A. Therefore, it is preferable to grasp and store the applied voltage information in consideration of this before factory shipment. .

  As described above, the control unit 30a uses the zero method control unit 30c and the control value output unit 35 to generate a control command value for driving the imaging unit 9A in a direction to cancel the shake detected by the shake detection circuit 30d. And output to the drive circuit (driver) 30e. The drive circuit 30e has, for example, a two-channel (2ch) linear driver (a driver that supplies an output voltage proportional to the input), and drives the drive unit 16 based on a control command value from the digital control unit 30b. . As a result, the imaging unit 9A is driven relative to the main body side member 12, and the camera shake is corrected.

  Although not shown, the cellular phone 1A is provided with an A / D conversion unit, an image processing unit, and an image memory as a processing unit that handles an image acquired by the imaging device 5. That is, an analog signal image acquired by the image sensor is converted into a digital signal by the A / D converter, and after predetermined image processing is performed by the image processor, it is temporarily stored in the image memory. The The image stored in the image memory is recorded on the memory card as a recording image or displayed on the display unit 71 as a live view display image. Thus, image data is generated by the image processing unit or the like based on the output signal from the image sensor. Various processes relating to image generation are also performed based on the control of the control unit 30a.

<Control during camera shake correction>
FIG. 7 is a diagram for explaining control at the time of camera shake correction in the mobile phone 1A.

  In the mobile phone 1A, two types of control methods (cooperative control and independent control) can be switched depending on the presence or absence of panning during the camera shake correction operation, which will be described below.

  In the normal camera shake correction control in the mobile phone 1A, the output signal of the shake detection sensor 8 is constantly monitored so that the output of the shake detection sensor 8 is stopped (zero) as shown in FIG. Servo control (closed control) with respect to the target angle (θpd, θyd) is performed. That is, feedback control is performed so that the current angle (θp, θy) detected by the angle detection unit 31 as a measurement value related to driving of the imaging unit 9A matches the target angle (θpd, θyd) that is the drive target value. In this case, the optimal control value for the pair of push-pull SMAa and SMAb is determined by the PID control in the zero method control unit 30c, and the driver A for SMAa and the driver B for SMAb in the drive circuit 30e. Is output.

  As described above, in the normal camera shake correction control, the SMAa and SMAb are energized based on the deviation between the drive target value and the measurement value related to the driving of the imaging unit 9A, and the two SMA actuators are cooperatively controlled. The responsiveness can be improved.

  On the other hand, when panning is detected during camera shake correction (for example, panning is determined based on whether or not a constant angular velocity is detected for a certain period of time by the shake detection sensor 8), the movement of the mobile phone 1A intended by the user ( Therefore, open control (open loop control) for holding the imaging unit 9A at the center position is performed without performing the servo control shown in FIG. 7A (FIG. 7B). That is, the applied voltage is applied independently to each of the two SMA actuators without being based on the deviation between the target angle (drive target value) and the current angle (measured value) regardless of the hand shake state of the mobile phone 1A. Independent control is performed. About the applied voltage of each SMA, in order to improve the precision which hold | maintains the imaging unit 9A in a center position rather than the center voltage (for example, 1.5V) obtained by (SMA resistance value) x (SMA bias current). Further, it is preferable that the voltage is a value obtained by adding about 0.3V to the above 1.5V.

  Hereinafter, the camera shake correction control during normal time and the control during panning will be described in detail.

<Normal image stabilization control>
FIG. 8 is a diagram for explaining applied voltages applied to the pair of SMAa and SMAb in normal camera shake correction control.

  In the normal camera shake correction control, the gain is set by the PID operation (see FIG. 7A) for the deviation between the target angle and the current angle. However, for convenience of explanation, the gain is set only by the P operation. As an example, a normal camera shake correction operation will be described below.

  When controlling the imaging unit 9A to the center position (see FIG. 5B), first, a voltage of +1.5 V is applied to both SMAa and SMAb. As a result, the generated forces (shrinkage forces) of SMAa and SMAb are substantially equal, and the imaging unit 9A can be held near the center position.

  Here, when an angle difference Δθ between the current angle detected by the angle detection unit 31 and the target angle occurs, the applied voltage shown in the graph of FIG. 8, specifically, the following equations (1) and (1): The applied voltage calculated by (2) is applied to SMAa and SMAb.

(Applied voltage of SMAa) = 1.5 + 3 × (Δθ) (1):
(Applied voltage of SMAb) = 1.5-3 × (Δθ) (2):
As described above, by performing cooperative control of SMAa and SMAb according to the angle difference Δθ, appropriate camera shake correction control can be performed. This operation will be described in detail below.

  FIG. 9 is a flowchart showing a normal camera shake correction operation. This operation is performed by the digital control unit 30b.

  When the release button 29 is fully pressed by the user and the camera shake correction operation is started, the zero method control unit 30c takes in the current angle (θp, θy) of the imaging unit 9A from the angle detection unit 31 (step ST1).

  In step ST2, the angles (θp, θy) acquired in step ST1 are set as target angles (θpd, θyd).

  In step ST3, as in step ST1, the zero method control unit 30c takes in the current angle (θp, θy) of the imaging unit 9A from the angle detection unit 31.

  In step ST4, the angle differences Δθp and Δθy between the target angles (θpd, θyd) set in step ST2 and the current angles (θp, θy) acquired in step ST3 are expressed by the following equations (3) and (4). ).

Δθp = θpd−θp (3):
Δθy = θyd−θy (4):
In step ST5, the applied voltage of a pair of SMAa and SMAb is determined. In this case, the applied voltage of each SMA is calculated by, for example, Expression (1) and Expression (2).

  In step ST6, based on the applied voltage of each SMA determined in step ST5, the control value of each SMA is output to the drive circuit 30e.

<Control during panning>
FIG. 10 is a flowchart showing an operation during panning. This operation is performed by the digital control unit 30b.

  In step ST11, the center instructing unit 37 reads information on the voltage applied to each SMAa and SMAb for holding the imaging unit 9A at the center position at room temperature.

  In step ST12, the current temperature is captured. Specifically, temperature information is acquired from a temperature sensor (not shown) provided in the mobile phone 1A.

  In step ST13, the applied voltage information at room temperature of each SMA read in step ST11 is corrected with the current temperature acquired in step ST12, and the applied voltage of each SMA is determined. Specifically, the applied voltages of SMAa and SMAb are calculated by the following equations (5) and (6).

(Applied voltage of SMAa) = V0a + α × (25−tn) (5):
(Applied voltage of SMAb) = V0b + α × (25−tn) (6):
However, V0a: applied voltage of SMAa necessary for center holding at room temperature (25 degrees),
V0b: SMAb applied voltage required for center holding at room temperature (25 degrees),
α: temperature correction coefficient of applied voltage, tn: current temperature.

  Accordingly, the energizing current can be suppressed in a state where the ambient temperature of the mobile phone 1A is high and the SMA temperature easily rises, and the energizing current can be increased in a state where the ambient temperature is low and the SMA temperature is difficult to rise. Appropriate control according to the environment becomes possible.

  In step ST14, the control value of each SMA is output to the drive circuit 30e based on the applied voltage of each SMA determined in step ST13.

  When the panning is not performed in the camera shake correction control (normal time) by the operation of the mobile phone 1A as described above, the control method is selected in which the two SMA actuators are servo-controlled and coordinated. Since a control method for performing open control and independently controlling each of the two SMA actuators is selected, switching between cooperative control and independent control can be performed appropriately. As a result, responsiveness can be improved during normal camera shake correction, and the user does not feel uncomfortable during panning.

  Note that it is not essential to perform the panning operation shown in the flowchart of FIG. 10 in the mobile phone 1A, and the panning operation described below may be performed.

  FIG. 11 is a flowchart showing another operation during panning. This operation is performed by the digital control unit 30b.

  In steps ST21 to ST24, operations similar to those in steps ST11 to ST14 shown in FIG. 10 are performed.

  In step ST25, a center signal for detecting the center position of the image pickup unit 9A shown in FIG. For example, the center signal is acquired by a photo interrupter provided in the camera shake correction system 10A.

  In step ST26, the current angle (θp, θy) of the imaging unit 9A is taken from the angle detection unit 31.

  In step ST27, the applied voltage of each SMA is reset so that the imaging unit 9A is held at the center position based on the center signal and the current angle signal captured in steps ST25 to ST26. Thereby, the optimum applied voltage of each SMA according to the attitude | position of the mobile telephone 1A, etc. can be determined.

  In step ST28, based on the application voltage of each SMA reset in step ST27, the control value of each SMA is output to the drive circuit 30e.

  With the above panning operation, reliable center holding can be performed even when it is difficult to hold the center of the imaging unit 9A by applying a predetermined voltage to each SMA.

  In the normal camera shake correction in the cellular phone 1A, it is preferable to perform one of the three applied voltage control methods described below.

(1) Analog Drive Control FIG. 12 is a diagram for explaining an analog control operation in the camera shake correction system 10A. Here, FIG. 12A shows the signal waveform at the target position, and FIG. 12B shows the signal waveforms Ja and Jb of the voltage applied to SMAa and SMAb. Note that the vertical axis in FIG. 12A represents the driving amount in the positive direction of displacement (FIG. 4) with Pi = 0 as the center position of the imaging unit 9A shown in FIG. 5B.

  In the digital control unit 30b, when the sinusoidal target position signal shown in FIG. 12 (a) is set, the drive control applies voltage to the SMAa as shown by the waveform Ja in FIG. 12 (b). A signal is generated, and a drive control signal for applying a voltage to the SMAb as shown by a waveform Jb in FIG. 12B is generated. The characteristics of these signal waveforms Ja and Jb will be described below.

  With respect to the signal waveform Ja and the signal waveform Jb, a constant DC voltage necessary for energizing the current value in the SMA transformation temperature region shown in FIG. 3 is set as the bias voltage Bs, and the bias voltage Bs is used as a reference. The analog signal is amplified according to the target position signal shown in FIG. The bias current value of this embodiment is set to a current value necessary for heating to a specific temperature within a temperature range from the SMA transformation start temperature to the transformation end temperature. For example, the SMA transformation temperature shown in FIG. A current value Im that is an intermediate value between the upper and lower limit current values I1 and I2 is set in the region.

  When the signal waveform Ps1 that moves the imaging unit 9A in the positive direction of displacement is input in the time zone t1 (FIG. 12A), the digital control unit 30b relates to the SMAa that requires the contraction operation, as shown in FIG. A drive control signal obtained by adding a voltage value proportional to the signal waveform Ps1 to the bias voltage Bs as in the signal waveform Ja1 is output to the drive circuit 30e.

  On the other hand, for the SMAb that is expanded without the need for contraction, when the heat dissipation rate of the SMA is substantially equal to the heating rate, the signal waveform Ja1 as in the signal waveform Jb1 of FIG. The voltage value a added from the bias voltage Bs is subtracted from the bias voltage Bs. When the heat dissipation rate of SMA is ½ of the heating rate, a voltage value twice the voltage value a added from the bias voltage Bs in the signal waveform Ja1 is subtracted from the bias voltage Bs and given to the SMAb. .

  As described above, the signal waveform Ja1 of the applied voltage corresponding to the drive current signal obtained by adding the current signal proportional to the displacement target value to the bias current signal is generated for one SMA 25a that performs the restoring operation of the two SMAs. In addition, in order to generate the signal waveform Jb1 of the applied voltage corresponding to the drive current signal obtained by subtracting the current signal corresponding to the displacement target value and the heat dissipation characteristic of the SMA 25 from the bias current signal for the other SMA 25b that does not perform the restoration operation. The response of the SMA displacement can be improved.

(2) Thinning Control FIG. 13 is a diagram for explaining the thinning control operation in the camera shake correction system 10A. Here, FIG. 13A shows the signal waveform of the target position, and FIG. 13B shows the pulse signal Pt. FIGS. 13C and 13D show signal waveforms La and Lb of applied voltages to SMAa and SMAb.

  In the digital control unit 30b, based on the target position signal Ps shown in FIG. 13 (a), the signal waveform Ja to be applied to each SMA as shown in FIG. Jb is generated.

  Then, the signal waveforms Ja and Jb and the pulse signal Pt (FIG. 13B), which is a thinned signal created in the digital control unit 30b, are overlapped to perform the process shown in FIG. 13C. The SMAa drive waveform La and the SMAb drive waveform Lb shown in FIG. 13D are generated. The pulse signal Pt has a frequency at which SMA does not respond (respond), for example, a frequency of 1 Hz or more.

  Since the voltage is applied to the SMAa and SMAb based on the signal waveforms La and Lb thinned out by using the pulse signal Pt in this way, it corresponds to the ratio (duty ratio) between the ON time and the OFF time of the pulse signal Pt. The input power can be reduced. Note that if the duty ratio corresponding to the thinning-out rate becomes small, electric power for displacing the SMA to the target position cannot be supplied and the performance deteriorates. Therefore, the average value of the energized current per unit time is the SMA transformation temperature region shown in FIG. Set the duty ratio to be within.

  As described above, by thinning out the driving current signal of SMA, power can be saved in the camera shake correction system 10A.

(3) PWM Drive Control FIGS. 14 and 15 are diagrams for explaining the operation of PWM control in the camera shake correction system 10A. Here, FIGS. 14 (a) and 15 (a) show signal waveforms Na1 and Na2 of the voltage applied to SMAa, and FIGS. 14 (b) and 15 (b) show the signal of the applied voltage to SMAb. Waveforms Nb1 and Nb2 are shown.

  In the digital control unit 30b, an applied voltage is applied to each SMA based on the pulse signal (PWM), and signal waveforms Na1 and Nb1 shown in FIG. 14 as pulse signals corresponding to the reference bias voltage Bs (12 (b)). Is set. These signal waveforms Na1 and Nb1 are formed as pulse signals having a duty ratio set to 50%, and are complementary signals in which one is turned off when the other is turned on. Specifically, as shown in FIGS. 14 (a) and 14 (b), the on-time of each signal waveform Na1, Nb1 is half the time of one pulse period tm of each waveform signal Na1, Nb1. Set to 5 tm. The carrier frequency of the pulse signal is set to a level at which the influence of the drive error due to following the pulse signal itself can be ignored by setting the frequency sufficiently high (for example, 1 kHz or more) with respect to the SMA response. Try to suppress.

  In order to drive the imaging unit 9A in the positive direction of displacement, signal waveforms Na2 and Nb2 shown in FIG. 15 are generated by the digital control unit 30b. That is, for the signal waveform Na2 for SMAa and the signal waveform Nb2 for SMAb, an 80% duty ratio increased by 30% with respect to the signal waveform Na1 having a duty ratio of 50% shown in FIG. % Duty ratio and a complementary relationship.

  By repeatedly applying such voltages based on the signal waveforms Na2 and Nb2 to the SMAa and SMAb, the contraction operation of the SMAa is continuously performed and the SMAb expands. For example, the target position shown in FIG. The imaging unit 9A is moved like the signal Ps1.

  In order to drive the imaging unit 9A in the negative direction of displacement, for example, the signal waveform Nb2 in FIG. 15 (b) is the SMAa drive waveform, and the signal waveform Na2 in FIG. 15 (a) is the SMAb drive waveform. good.

  By performing the PWM control as described above, the responsiveness of the SMA displacement can be improved as in the case of the analog drive control.

Second Embodiment
<Key phone configuration>
FIG. 16 is a side view showing a mobile phone 1B incorporating a camera shake correction system 10B according to the second embodiment of the present invention. FIG. 17 is a diagram showing in more detail elements included in the camera shake correction system 10B.

  The cellular phone 1B has a configuration similar to that of the cellular phone 1B of the first embodiment, but the shake detection sensor 8 of the cellular phone 1B is fixed to the outer wall of the member 12a, and the cellular phone 1B The imaging unit 9B is different from the imaging unit 9B in that a position sensor 80 that is fixed to the imaging unit 9B and performs position detection is newly provided.

  FIG. 18 is a diagram showing an outline of a control system related to camera shake correction in the mobile phone 1B. Hereinafter, the difference from the configuration of the mobile phone 1A shown in FIG. 6 will be described with reference to the drawing.

  In the mobile phone 1B, since the position sensor 80 is built in the imaging unit 9B as described above, servo control related to the position of the imaging unit 9B is performed by the control unit 40a.

  That is, the digital control unit 30b of the mobile phone 1B includes a servo control unit 40c including a target position setting unit 41, a current position setting unit 42, and an optimum control value calculation unit 34. In the servo control unit 40c, a target position difference related to the outputs of the target position setting unit 41 and the current position setting unit 42 is calculated, and an optimum control value obtained by multiplying the target position difference by an optimum gain is obtained as an optimum control value. The calculation unit 34 calculates and outputs the result.

  The target position setting unit 41 converts the angle information detected by the angle detection unit 31 into position information corresponding to the position sensor 80, and sets the target position of the imaging unit 9B.

  The current position setting unit 42 sets the position information detected by converting the output of the position sensor 80 by the position detection unit 43 as the current position of the imaging unit 9B. Here, the position sensor 80 includes a P position detection sensor 80a that detects the position of the imaging unit 9B in the pitch direction, and a Y position detection sensor 80b that detects the position of the imaging unit 9B in the yaw direction. Note that the position sensor 80 is not necessarily provided with two one-dimensional position sensors 80a and 80b, and may be provided with one two-dimensional detection type position sensor.

<Control during camera shake correction>
FIG. 19 is a diagram for explaining control at the time of camera shake correction or the like in the mobile phone 1B.

  In the mobile phone 1B, cooperative control of the two SMAa and SMAb is performed when camera shake correction is performed, and independent control is performed when camera shake correction is not performed. More specifically, while coordinated servo control is performed in camera shake correction during normal time or panning, in each operation related to one-SMA performance detection unrelated to camera shake correction, end detection of the imaging unit 9B, and center holding when camera shake is off. Has a configuration in which open loop independent control is performed.

  In the normal camera shake correction control in the cellular phone 1A, the target position setting unit 41 sets the current position of the imaging unit 9B while constantly monitoring the output signal of the position sensor 80 as shown in FIG. Servo control is performed to match the position. That is, feedback control is performed so that the current position (Pp, Py) detected by the position detection unit 43 as a measurement value related to driving of the imaging unit (movable unit) 9A matches the target position (Ppd, Pyd) that is the drive target value. Is done. In this case, the optimal control value for the pair of push-pull SMAa and SMAb is determined by PID control in the servo control unit 40c, and is output to the driver A for SMAa and the driver B for SMAb in the drive circuit 30e. Is done.

  Further, when panning is performed at the time of camera shake correction in the mobile phone 1B, it is a movement (vibration) operation of the mobile phone 1A intended by the user, and therefore the above-described normal camera shake correction control is not performed, and FIG. As shown in FIG. 4, the target position of the imaging unit 9B is fixed at, for example, the center position (reference position), and the SMAa and SMAb are coordinated so that the imaging unit 9B is held at the center position.

  On the other hand, in the case of performing one-side SMA performance detection in which the driving performance of each SMA is inspected in order to grasp the performance degradation status etc. in the mobile phone 1B, as shown in FIG. 19B, a pair of SMAa and SMAb are opened. Independent control of the loop. The reason why the SMAa and the SMAb are independently controlled in this way is that it is difficult to determine whether the performance of the actuator has deteriorated due to a mechanical trouble or due to a failure of the SMA by performing cooperative control.

  Further, when detecting the end of the imaging unit 9B, that is, the movable limit in the cellular phone 1B, open-loop independent control is performed on the pair of SMAa and SMAb as shown in FIG. In the camera shake correction system 10B, when the driving unit 16 is driven in a state where the optimum applied voltage is set by cooperative control, the generated force is increased by the SMA actuator, so that the impact when reaching the end is excessive, There is a risk of degrading the performance of the actuator itself. Therefore, in such a case, the breakage of the actuator is prevented by controlling each SMA to open independently and suppressing the generated force.

  Further, when the image pickup unit 9B is held at the center position (reference position) when the camera shake correction is turned off in the mobile phone 1B, open-loop independent control is performed for a pair of SMAa and SMAb as shown in FIG. Do. That is, in the imaging unit 9B, as described above, the structure is mechanically held at the substantially center position by the elastic support portion 11c, but in order to improve the holding accuracy of the center position when camera shake correction is off. Each SMA is driven independently. In this case, the power supply of the shake detection circuit system of the shake detection circuit 30d and the position detection unit 43 is turned off, and a constant applied voltage is supplied to each SMA (SMAa, SMAb).

  Below, each operation | movement in the mobile telephone 1B is demonstrated in detail.

<Normal image stabilization control>
FIG. 20 is a flowchart showing a camera shake correction operation in a normal state. This operation is performed by the digital control unit 40b.

  When the release button 29 is fully pressed by the user and the camera shake correction operation is started, the servo control unit 40c takes in the current angle of the imaging unit 9B from the angle detection unit 31 (step ST31).

  In step ST32, the target position (Ppd, Pyd) is set by the target position setting unit 41 based on the angle taken in in step ST31.

  In step ST33, the servo control unit 40c takes in the current position (Pp, Py) of the imaging unit 9B from the position detection unit 43.

  In step ST34, angle differences ΔPp and ΔPy between the target position (Ppd, Pyd) set in step ST32 and the current position (Pp, Py) captured in step ST33 are expressed by the following equations (7) and (8). ).

ΔPp = Ppd−Pp (7):
ΔPy = Pyd−Py (8):
In step ST35, the voltage applied to the pair of SMAa and SMAb is determined. Here, for example, when the target position of the imaging unit 9B is the center position, the applied voltage of each SMA is calculated by the following equations (9) and (10).

(Applied voltage of SMAa) = 1.5 + αb × (ΔP) (9):
(Applied voltage of SMAb) = 1.5−αb × (ΔP) (10):
Where αb is the optimum gain.

  In step ST36, based on the applied voltage of each SMA determined in step ST35, the control value of each SMA is output to the drive circuit 30e.

  As described above, in the normal camera shake correction, the latest angle information is taken in and servo control (cooperative control) for the target value is continued.

<Control during panning>
FIG. 21 is a flowchart showing an operation during panning. This operation is performed by the digital control unit 40b.

  Since the panning drive control is preferably controlled with the drive unit regardless of the shake detection amount, the servo control (cooperative control) for setting and fixing the current position to the next target position is continued. Become.

  When the panning operation is started, the servo control unit 40c takes in the current position of the imaging unit 9B from the angle detection unit 31 (step ST41).

  In step ST42, based on the current position (Pp, Py) captured in step ST41, the target position setting unit 41 sets the target position (Ppd, Pyd).

  In steps ST43 to ST44, operations similar to those in steps ST33 to ST34 in FIG. 20 are performed.

  In step ST45, the voltage applied to the pair of SMAa and SMAb is determined. Here, for example, when the imaging unit 9B is held at the center position, the applied voltage of each SMA is calculated by the following equations (11) and (12).

(Applied voltage of SMAa) = 1.5 + αc × (ΔP) (11):
(Applied voltage of SMAb) = 1.5−αc × (ΔP) (12):
Where αc is the optimum gain.

  As for the above-mentioned optimum gain αc, a gain value that can hold the imaging unit 9B at a fixed position at the time of panning is sufficient, so that the above equations (9) and (10) do not react to ΔP that is a minute deviation. It is preferable to set it smaller than the optimum gain αb.

<Operation when detecting single SMA performance>
FIG. 22 is a flowchart showing the operation at the time of detecting the piece SMA performance. This operation is performed by the digital control unit 40b.

  In steps ST51 to ST52, the applied voltages of the pair of SMAa and SMAb are set to 2V and 0V, respectively.

  In step ST53, the control value of each SMA is output to the drive circuit 30e based on the applied voltage of each SMA set in steps ST51 to ST52. As a result, driving of one SMAb can be stopped and only the other SMAa can be driven.

  In step ST54, the performance of SMAa is determined. In this case, for example, it is determined whether the driving speed va of the imaging unit 9B is larger than a threshold value va that can be determined to be normal performance.

  In steps ST55 to ST56, the applied voltages of the pair of SMAa and SMAb are set to 0V and 2V, respectively.

  In steps ST57 to ST58, operations similar to those in steps ST53 to ST54 are performed.

  With the above operation, the performance of each SMA can be appropriately inspected. In addition, the ambient temperature of the cellular phone 1B can be estimated based on the driving speed detected in the above-described step ST54 and step ST58 from the SMA characteristic that the driving speed increases because the heating time is shortened when the ambient temperature is high. Become.

<Termination detection of imaging unit 9B>
FIG. 23 is a flowchart showing an operation at the time of detecting the end of the imaging unit 9B. This operation is performed by the digital control unit 40b.

  In steps ST61 to ST62, the applied voltages of the pair of SMAa and SMAb are set to 2.3V and 0V, respectively. Here, for SMAb, an applied voltage of 2.3 V, which is lower than the maximum applicable voltage (3 V) and necessary for generating a desired driving force, is set.

  In step ST63, based on the applied voltage of each SMA set in steps ST61 to ST62, the control value of each SMA is output to the drive circuit 30e. As a result, driving of the SMAb is stopped (for example, the bias voltage Bs in FIG. 12 is set to zero), only the SMAa is driven, and the imaging unit 9B can be displaced in the + direction (FIG. 4).

  In step ST64, the digital control unit 40b captures the current position of the imaging unit 9B from the position detection unit 43.

  In step ST65, it is determined whether or not the current position captured in step ST64 has changed. If there is no change in the current position, the process proceeds to step ST66, and if there is a change, the process returns to step ST64.

  In step ST66, since there is no change in the current position, this position is detected as the + end of the imaging unit 9B. For example, when the current position does not reach the terminal position stored before factory shipment, the voltage obtained by slightly increasing the applied voltage set in step ST62 is applied to SMAa to reach the terminal position. It is preferable to confirm.

  In addition, when the applied voltage which reaches | attains a termination | terminus is high, it considers that there exists some following malfunctions (performance degradation).

-Increase in mechanical frictional force-Degradation of SMA performance In this case, it is possible to improve performance by slightly increasing the servo gain to improve drive performance.

  In steps ST67 to ST68, the applied voltages of the pair of SMAa and SMAb are set to 0V and 2.3V, respectively. Thereby, the drive of SMAa can be stopped, only SMAb can be driven, and the image pick-up unit 9B can be displaced to-direction (FIG. 4).

  In steps ST69 to ST71, operations similar to those in steps ST63 to ST65 are performed.

  In step ST72, since there is no change in the current position, this position is detected as a negative end in the imaging unit 9B.

  As described above, independent termination detection has the following advantages.

  -Sensitive end detection is possible for SMA actuators that are easily destroyed by overheating, etc. (when end detection is performed by cooperative control, there is a high possibility that the SMA actuator will be destroyed).

  By independently detecting the end, it is possible to roughly determine whether the failure is a mechanical failure (increased frictional force) or an SMA failure.

<Center holding when camera shake is off>
FIG. 24 is a flowchart illustrating an operation at the time of holding the center when the camera shake is off. This operation is performed by the digital control unit 40b.

  In steps ST81 to ST84, operations similar to those in steps ST11 to ST14 shown in the flowchart of FIG. 10 are performed. However, as described above, the power of the camera shake detection circuit system is turned off, and each holding performance is ensured. The SMA application voltage is set low to save power.

  With the above-described operation of the mobile phone 1B, in the normal and panning camera shake correction, servo control is performed to select a control method for cooperative control of the two SMA actuators, and one-side SMA performance detection and imaging unit end detection, In the center holding operation of the image pickup unit when camera shake correction is turned off, open control is performed to select a control method for independently controlling each of the two SMA actuators. Therefore, switching between cooperative control and independent control can be performed appropriately.

<Modification>
◎ For the drive unit in each of the above embodiments, it is not essential to connect two SMAs in a push-pull relationship to the movable unit (imaging unit). For example, three SMAs are connected to the movable unit. You may make it connect from the direction shifted by 120 degrees.

1 is a side view showing a mobile phone 1A in which a camera shake correction system 10A according to a first embodiment of the present invention is incorporated. It is a figure which shows the element contained in 10 A of camera shake correction systems in detail. It is a figure which shows the characteristic of the energization current-displacement of SMA. It is a figure which shows the relationship between the applied current with respect to SMA, and the displacement of 9 A of imaging units. It is a figure for demonstrating the relationship between the applied current with respect to SMA, and the displacement of 9 A of imaging units. It is a figure which shows the outline | summary of the control system regarding the camera shake correction in 1 A of mobile phones. It is a figure for demonstrating the control at the time of camera shake correction | amendment in 1 A of mobile phones. It is a figure for demonstrating the applied voltage applied to a pair of SMAa and SMAb in camera shake correction control at the normal time. It is a flowchart which shows the camera shake correction operation | movement at the normal time. It is a flowchart which shows the operation | movement at the time of panning. It is a flowchart which shows the other operation | movement at the time of panning. It is a figure for demonstrating the operation | movement of the analog control in 10 A of camera-shake correction systems. It is a figure for demonstrating the operation | movement of thinning-out control in 10 A of camera-shake correction systems. It is a figure for demonstrating the operation | movement of PWM control in 10 A of camera-shake correction systems. It is a figure for demonstrating the operation | movement of PWM control in 10 A of camera-shake correction systems. It is a side view which shows the mobile telephone 1B incorporating the camera-shake correction system 10B which concerns on 2nd Embodiment of this invention. It is a figure which shows the element contained in the camera shake correction system 10B in detail. It is a figure which shows the outline | summary of the control system regarding the camera shake correction in the mobile telephone 1B. It is a figure for demonstrating control at the time of the camera-shake correction | amendment in the mobile telephone 1B. It is a flowchart which shows the camera shake correction operation | movement at the normal time. It is a flowchart which shows the operation | movement at the time of panning. It is a flowchart which shows the operation | movement at the time of piece SMA performance detection. It is a flowchart which shows the operation | movement at the time of the termination | terminus detection of the imaging unit 9B. It is a flowchart which shows the operation | movement at the time of center holding | maintenance at the time of camera shake OFF.

Explanation of symbols

1A, 1B Cellular phone 8 Shake detection sensors 9A, 9B Image pickup units 10A, 10B Shake correction system 11a Elastic support members 15, 15a, 15b Drive member 16 Drive unit 16P P (pitch direction) drive actuator 16Y Y (yaw direction) drive actuator 29 Release button 30a, 40a Control unit 30c Zero method control unit 30d Shake detection circuit 30e Drive circuit (driver)
31 Angle detector 40c Servo controller 41 Position detector 80 Position sensor

Claims (7)

A driving device capable of driving the movable part using two actuators connected to the movable part from different directions,
(a) measuring means for obtaining a measurement value relating to driving of the movable part;
(b) control means for controlling the drive of the movable part;
With
Each of the two actuators has a shape memory alloy, and the contraction force generated by energizing the shape memory alloy acts on the movable part from the different directions by the resultant force. While functioning as a driving actuator,
The control means includes
(b-1) the shrinkage force to reduce cooperatively deviation of the said measured value and the driving target value relating to driving of the movable portion so that the two actuators are generated respectively, the two actuators, respectively Cooperative control means for cooperatively controlling the two actuators by energizing each of the shape memory alloys with a current based on the deviation within a transformation temperature region of the shape memory alloy;
(b-2) Deriving in advance a current that causes each of the two actuators to generate the contraction force based on the drive target value without being based on the deviation, thereby energizing the movable part to a specific position. a first independent control for holding the, the current supplied to the one actuator to zero, a second independent for generating a contraction force to move the movable portion in one direction by passing a predetermined current to the other actuator Independent control means for selectively executing control;
(b-3) selection means for selectively executing cooperative control by the cooperative control means and independent control by the independent control means;
A drive device comprising: The drive device according to claim 1,
The two actuators enable camera shake correction related to the imaging means having the movable part,
The selection means includes
Means for executing the cooperative control when performing the shake correction, and executing the independent control when not performing the shake correction;
Drive apparatus according to claim Rukoto to have a. The drive device according to claim 1 or 2 ,
Before Symbol selection means,
Means for executing the second independent control when detecting a movable limit of the movable part ;
A drive device comprising: The drive device according to any one of claims 1 to 3,
The selection means includes
Means for executing the second independent control when inspecting the driving performance for each of the two actuators ;
A drive device comprising: The drive device according to any one of claims 1 to 4,
A reference position is determined for driving the movable part,
The selection means includes
Means for executing the first independent control when the movable part is held at the reference position ;
A drive device comprising: The drive device according to claim 1 ,
The two actuators enable camera shake correction related to the imaging means having the movable part,
The selection means includes
Means for executing the first independent control when panning related to the imaging means is performed during the camera shake correction, and executing the cooperative control when panning is not performed ;
A drive device comprising: A method of driving the movable part using two actuators connected to the movable part from different directions,
A measurement step of obtaining a measurement value related to driving of the movable part;
A control step for controlling the driving of the movable part;
With
Each of the two actuators has a shape memory alloy, and the contraction force generated by energizing the shape memory alloy acts on the movable part from the different directions by the resultant force. While functioning as a driving actuator,
The control step includes
Shape memory is stored in the shape memory alloy of each of the two actuators so that the two actuators generate the contraction force that cooperatively reduces the deviation between the drive target value and the measurement value relating to the driving of the movable part. A cooperative control step of cooperatively controlling the two actuators by energizing each of the currents based on the deviation within the transformation temperature region of the alloy;
A first independent holding the movable part at a specific position by deriving in advance and energizing each of the two actuators to generate a contraction force based on the drive target value, not based on the deviation. And a second independent control that generates a contraction force that moves the movable part in one direction by applying a predetermined current to the other actuator, with zero current applied to the one actuator. An independent control step to be performed;
A selective step of selectively executing cooperative control by the cooperative control step and independent control by the independent control step;
A driving method characterized by comprising :

Images