JP2012189657A - Camera shake correction device and imaging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform control for camera shake correction stably with a simple structure.SOLUTION: A camera shake correction device of the present invention comprises: a drive coil 110 which has a magnetic coil and drives a correction lens 124 for camera shake correction by magnetic force; a Hall element 130 for detecting a position of a moving member; a correction coil 140 which has a magnetic coil and is arranged facing the drive coil 110 with the Hall element 130 interposed between the correction coil 140 and the drive coil 110; and a correction circuit 320 for driving the correction coil 140 when a driving signal of the drive coil 110 includes a frequency component equal to or over a predetermined value.

Description

  The present invention relates to a camera shake correction apparatus and an imaging apparatus.

  In recent years, many camera systems having a camera shake correction function have been proposed for the purpose of improving operability. In a camera having a conventional camera shake correction function, camera shake vibration is detected using an angular velocity sensor or the like, and the camera shake is corrected by adjusting the position of a lens or a CCD (Charge Coupled Devices) based on the detected amount. Yes. For example, as described in Patent Document 1, a position detection method using a magnet and a Hall element is known for detecting the position of a lens or a CCD.

  In order to drive the camera lens in accordance with camera shake, it is necessary to control the driving of a moving member that moves the lens and the CCD. A voice coil motor (hereinafter referred to as VCM) can be used for driving the moving member. The VCM includes a magnet and a coil, and the moving member is driven by a driving force of a magnetic field generated from the magnet and the coil. And in order to detect the position of the driven moving member, the magnet and Hall element which were mentioned above are used. The Hall element detects magnetism generated from the magnet and detects the current position of the moving member. By correctly detecting the current position of the moving member, it is possible to drive the moving member to the control target position calculated according to the detected camera shake vibration.

  However, when a moving member is driven using a magnet and a coil, the Hall element that detects the position of the magnet detects not only the magnetism generated from the magnet but also the magnetism generated by the current flowing through the coil. The position of could not be detected correctly. In other words, the position of the magnet cannot be detected correctly due to the influence of magnetism generated from the coil, and the current position of the moving member cannot be detected correctly, so that the moving member cannot be accurately driven to the control target position, and stable movement is achieved. There was a problem that the drive control of the members could not be performed.

  In view of this point, Patent Document 2 describes a method for correctly detecting the current position of a moving member by detecting a magnetic component generated from a coil of a VCM and subtracting an unnecessary magnetic component by a control circuit. ing.

JP 2009-47951 A JP 2009-159722 A

  However, in the technique described in Patent Document 2, a predetermined magnetic component corresponding to the magnetic component generated from the coil is subtracted from the magnetic component detected by the Hall element, but the magnetic component generated by the coil is measured. Since this is not possible, it is necessary to perform circuit matching during manufacturing. For this reason, it is assumed that the problem that the matching man-hour at the time of manufacture will increase arises.

  Therefore, the present invention has been made in view of the above problems, and an object of the present invention is a new and improved technique capable of stably performing control for camera shake correction with a simple configuration. Another object of the present invention is to provide an image stabilization apparatus and an imaging apparatus.

  In order to solve the above-described problems, according to one aspect of the present invention, a drive actuator that has a magnetic coil and drives a moving member for camera shake correction by magnetic force, and a magnetic sensor that detects the position of the moving member, There is provided a camera shake correction apparatus comprising: a magnetic coil; and a drive circuit that drives the correction actuator when the drive signal of the drive actuator includes a frequency component equal to or greater than a predetermined value. .

  According to the above configuration, the correction actuator is disposed opposite to the drive actuator with the magnetic sensor interposed therebetween, and the correction actuator is driven when the drive actuator drive signal includes a frequency component greater than or equal to a predetermined value. Is done. Therefore, the induction magnetism generated by the drive actuator is canceled by the induction magnetism generated by the correction actuator, and the output of the magnetic sensor can be prevented from being influenced by the induction magnetism.

  The predetermined value is a frequency at which an inflection point occurs in the output of the magnetic sensor due to induction magnetism of the drive actuator. According to this configuration, the correction actuator is driven when the drive signal of the drive actuator includes a frequency component equal to or higher than the frequency at which an inflection point is generated in the output of the magnetic sensor due to the induction magnetism of the drive actuator. It is possible to reliably prevent the output of the magnetic sensor from being influenced by induction magnetism.

  The drive actuator and the correction actuator are arranged at an equal distance from the magnetic sensor, and the magnetic coil of the correction actuator has the same specifications as the magnetic coil of the drive actuator, The direction is the reverse direction. According to this configuration, the drive actuator and the correction actuator are arranged at an equal distance from the magnetic sensor, and the magnetic coil of the correction actuator has the same specifications as the magnetic coil of the drive actuator, and the coil winding direction Therefore, the induced magnetism generated by the drive actuator can be reliably canceled by the induced magnetism generated by the correction actuator.

  The distance between the correction actuator and the magnetic sensor is shorter than the distance between the drive actuator and the magnetic sensor, and the current value flowing through the magnetic coil of the correction actuator is the current flowing through the magnetic coil of the drive actuator. Less than the value. According to this configuration, when the distance between the correction actuator and the magnetic sensor is shorter than the distance between the drive actuator and the magnetic sensor, the current value flowing through the magnetic coil of the correction actuator is the current value flowing through the magnetic coil of the drive actuator. Since it is possible to cancel the induced magnetism generated by the drive actuator in a smaller state, the power consumption of the correction actuator can be minimized.

  The distance between the correction actuator and the magnetic sensor is shorter than the distance between the drive actuator and the magnetic sensor, and the number of turns of the magnetic coil of the correction actuator is less than the number of turns of the magnetic coil of the drive actuator. . According to this configuration, when the distance between the correction actuator and the magnetic sensor is shorter than the distance between the drive actuator and the magnetic sensor, the number of turns of the magnetic coil of the correction actuator is made smaller than the number of turns of the magnetic coil of the drive actuator. Since the induction magnetism generated by the drive actuator in the state can be canceled, the configuration of the correction actuator can be further simplified.

  In order to solve the above problems, according to another aspect of the present invention, an image sensor on which a subject image is formed and a magnetic coil, and a correction lens for camera shake correction or the image sensor is magnetically A drive actuator that is driven by a magnetic sensor, a magnetic sensor that detects a position of a magnet driven together with the correction lens or the imaging device, and a magnetic coil, and is disposed opposite to the drive actuator with the magnetic sensor interposed therebetween. There is provided an imaging apparatus comprising: a correction actuator for driving the correction actuator; and a drive circuit for driving the correction actuator when a frequency component equal to or greater than a predetermined value is included in a drive signal of the drive actuator.

  According to the above configuration, the correction actuator is disposed opposite to the drive actuator with the magnetic sensor interposed therebetween, and the correction actuator is driven when the drive actuator drive signal includes a frequency component greater than or equal to a predetermined value. Is done. Therefore, the induction magnetism generated by the drive actuator is canceled by the induction magnetism generated by the correction actuator, and the output of the magnetic sensor can be prevented from being influenced by the induction magnetism.

  The predetermined value is a frequency at which an inflection point occurs in the output of the magnetic sensor due to induction magnetism of the drive actuator. According to this configuration, the correction actuator is driven when the drive signal of the drive actuator includes a frequency component equal to or higher than the frequency at which an inflection point is generated in the output of the magnetic sensor due to the induction magnetism of the drive actuator. It is possible to reliably prevent the output of the magnetic sensor from being influenced by induction magnetism.

  The drive actuator and the correction actuator are arranged at an equal distance from the magnetic sensor, and the magnetic coil of the correction actuator has the same specifications as the magnetic coil of the drive actuator, The direction is the reverse direction. According to this configuration, the drive actuator and the correction actuator are arranged at an equal distance from the magnetic sensor, and the magnetic coil of the correction actuator has the same specifications as the magnetic coil of the drive actuator, and the coil winding direction Therefore, the induced magnetism generated by the drive actuator can be reliably canceled by the induced magnetism generated by the correction actuator.

  The distance between the correction actuator and the magnetic sensor is shorter than the distance between the drive actuator and the magnetic sensor, and the current value flowing through the magnetic coil of the correction actuator is the current flowing through the magnetic coil of the drive actuator. Less than the value. According to this configuration, when the distance between the correction actuator and the magnetic sensor is shorter than the distance between the drive actuator and the magnetic sensor, the current value flowing through the magnetic coil of the correction actuator is the current value flowing through the magnetic coil of the drive actuator. Since it is possible to cancel the induced magnetism generated by the drive actuator in a smaller state, the power consumption of the correction actuator can be minimized.

  The distance between the correction actuator and the magnetic sensor is shorter than the distance between the drive actuator and the magnetic sensor, and the number of turns of the magnetic coil of the correction actuator is less than the number of turns of the magnetic coil of the drive actuator. . According to this configuration, when the distance between the correction actuator and the magnetic sensor is shorter than the distance between the drive actuator and the magnetic sensor, the number of turns of the magnetic coil of the correction actuator is made smaller than the number of turns of the magnetic coil of the drive actuator. Since the induction magnetism generated by the drive actuator in the state can be canceled, the configuration of the correction actuator can be further simplified.

  According to the present invention, it is possible to stably perform control for camera shake correction with a simple configuration.

It is a mimetic diagram showing an imaging device provided with a camera shake amendment device concerning one embodiment of the present invention. It is a schematic diagram for demonstrating the influence of the induction magnetism from the coil which generate | occur | produces in a Hall element. It is a characteristic view which shows the result of having measured the influence of the magnetism on the output of a Hall element. It is a characteristic view which shows as a comparison the result when a Hall element is not located directly above or around the drive coil and the Hall element is not affected by induction magnetism. It is a block diagram which shows the main structures of the camera-shake correction system which concerns on this embodiment. FIG. 7 is a characteristic diagram showing the gain and phase of servo open loop characteristics in the system shown in FIG. 6. It is a block diagram which shows the structure for driving a correction coil. It is a schematic diagram which shows the structure of a drive coil, a moving magnet, a Hall element, and a correction coil. It is a schematic diagram which shows the structure of a drive coil, a moving magnet, a Hall element, and a correction coil.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol.

  FIG. 1 is a schematic diagram illustrating an imaging apparatus 200 including a camera shake correction apparatus 100 according to an embodiment of the present invention. As illustrated in FIG. 1, the imaging apparatus 200 includes a camera shake correction apparatus 100, an imaging element 202, and an optical lens 204. The optical lens 204 forms a subject image on the imaging surface of the imaging element 202. The imaging element 202 is a sensor such as a CCD sensor or a CMOS sensor, and outputs a signal obtained by photoelectrically converting a subject image formed on the imaging surface.

  The camera shake correction apparatus 100 drives the correction lens 124 in a direction perpendicular to the optical axis 210 based on the camera shake when the user holds the imaging apparatus 200 to correct the camera shake. The camera shake correction apparatus 100 includes a drive coil 110, a moving magnet 120, a lens holding frame 122, a correction lens 124, a Hall element 130, and a correction coil 140.

  In FIG. 1, the correction lens 124 is held by a lens holding frame 122. The moving magnet 120 is fixed to the lens holding frame 122. The drive coil 110 generates induction magnetism when energized, and drives the moving magnet 120 in a direction perpendicular to the optical axis 210 by magnetic force. As a result, the lens holding frame 122 to which the moving magnet 120 is fixed moves together with the correction lens 124 in the direction perpendicular to the optical axis 210. Then, the movement of the correction lens 124 moves the position of the subject image on the imaging surface of the imaging element 202, so that camera shake can be corrected. In FIG. 1, only the driving coil 110 and the moving magnet 120 for driving the lens holding frame 122 in the vertical direction are shown, but the driving coil 110 and moving for driving the lens holding frame 122 in the horizontal direction are shown. A magnet 120 is provided separately. Therefore, the correction lens 124 can be moved in two directions, ie, a vertical direction and a horizontal direction with respect to the optical axis, and camera shakes in the vertical and horizontal directions can be corrected.

  In the present embodiment, the correction lens 124 is driven based on the amount of camera shake by the user, but the image sensor 202 may be driven in a direction perpendicular to the optical axis. In this case, it is not necessary to provide the correction lens 124, and the image sensor 202 is driven by attaching the image sensor 202 to the moving magnet 120.

  Hall element 130 detects the amount of movement of moving magnet 120. The correction coil 140 generates induction magnetism in the opposite direction to the drive coil 110 and cancels the induction magnetism of the drive coil 110 at the position of the Hall element 130, thereby suppressing the influence of the induction magnetism on the output of the Hall element 130. . Thereby, the Hall element 130 can accurately detect the position of the moving magnet 120. In the present embodiment, the position of the correction lens 124 or the image sensor 202 that is driven for camera shake correction is detected by using the Hall element 130, but other magnetic sensors such as an MR sensor can also be used. It is.

  FIG. 2 is a schematic diagram for explaining the influence of induced magnetism from the coil generated in the Hall element 130. The hall element 130 disposed on the upper side of the drive coil 110 is inherently capable of detecting the magnetism of the moving magnet 120 and accurately detecting its position. However, as shown in FIG. 2, when the correction coil 140 is not provided, the Hall element 130 is affected by induced magnetism generated by the current flowing through the drive coil 110. FIG. 3 is a characteristic diagram showing a result of measuring the influence of magnetism on the output of the Hall element 130. In FIG. 3, the horizontal axis indicates the frequency, and the vertical axis indicates the result of measuring the ratio of the output of the Hall element 130 to the actual moving distance of the moving magnet 120. The actual moving distance of the moving magnet 120 can be accurately measured by a laser sensor or the like.

  The Hall element outputs a value proportional to the moving distance of the moving magnet 120. Therefore, the ratio between the actual moving distance of the moving magnet 120 and the output of the Hall element 130 is originally a constant value. However, as shown in FIG. 3, the ratio between the moving distance of the moving magnet 120 and the output of the Hall element 130 is constant up to a certain frequency (around 100 Hz), but there is an inflection point in the vicinity of the frequency of 130 Hz. It can be seen that the value of the ratio gradually increases when the value becomes larger than around 130 Hz.

  When the current flowing through the drive coil 110 is constant, the moving amount of the moving magnet 120 with respect to the frequency decreases with an inclination of −40 dB / dec, and when the frequency is about 100 Hz, the moving amount of the moving magnet 120 becomes several μm or less. As described above, when the frequency is about 100 Hz, the moving amount of the moving magnet 120 becomes a minute amount, and when the magnetic element generated from the driving coil 110 is affected by the magnetic force generated from the driving coil 110 with respect to the original output level of the Hall element 130, Since the output level becomes large, the characteristics shown in FIG. 3 appear.

  On the other hand, FIG. 4 shows a comparison result when the Hall element 130 is not positioned directly above or around the drive coil 110 and the Hall element 130 is not affected by induction magnetism. In FIG. 4, the horizontal axis indicates the frequency as in FIG. 3, and the vertical axis indicates the ratio of the output of the Hall element 130 to the actual moving distance of the moving magnet 120. In this case, even when the frequency changes, the ratio of the output of the Hall element 130 to the moving distance of the moving magnet 120 is constant, and the inflection point as shown in FIG. 3 does not occur. As described above, when influenced by induction magnetism, the ratio between the moving distance of the moving magnet 120 and the output of the Hall element 130 changes, and the amount of movement cannot be detected accurately.

  FIG. 5 is a block diagram illustrating a main configuration of the camera shake correction system 300 according to the present embodiment. As shown in FIG. 5, a camera shake correction system 300 includes a gyro sensor 302, an amplifier 304, an MCU (microcomputer) 306, a subtracting unit 308, a servo filter 310, a driver circuit 312, an actuator 313 (drive coil 110), a moving magnet 120, and A correction lens 124 (or the image sensor 202) driven thereby, a Hall element 130 for detecting the position of the moving magnet 120, and an amplifier 314 are configured.

  In FIG. 5, the hand vibration detected by the gyro sensor 302 is amplified by the amplifier 304 and then input to the MCU 306. The position of the moving magnet 120 to be driven is detected by the Hall element 130, and the detection result is output from the Hall element 130, amplified by the amplifier 314, and then input to the MCU 306.

  The MCU 306 calculates the amount of camera shake from the camera shake vibration detected by the gyro sensor 302, and calculates a correction value (camera shake correction value) for correcting the camera shake. The subtracting unit 308 compares the camera shake correction value with the position detection result of the Hall element 130, and inputs the result obtained by subtracting the position detection result of the Hall element 130 from the camera shake correction value to the servo filter 310.

  The servo filter 310 controls the gain and phase for performing appropriate control, drives the actuator 313 (drive coil 110) through the driver circuit 312, and moves the moving magnet 120 to the target position. As described above, since the result of subtracting the position of the moving magnet 120 from the detected amount of camera shake is input to the servo filter 310, it is necessary in consideration of the position of the moving magnet 120 with respect to the amount of camera shake. The moving magnet 120 is driven to a desired target value. Position information when the moving magnet 120 is moved is detected by the Hall element 130, compared with the target value from the MCU 306 again, and input to the servo filter 310. Thus, in the camera shake correction system 300 according to the present embodiment, a servo loop indicated by a white line arrow in FIG. 5 is configured. The servo loop drives the actuator 313 so that the output of the hall element 130 matches the camera shake correction value output from the MCU 306.

  As described above, the camera shake correction system 300 performs feedback control that corrects camera shake while always comparing the target value (camera shake correction value) calculated from the MCU 306 with the current position information of the moving magnet 120. In order to improve camera shake correction performance, stabilization of this feedback control (servo loop) and a high gain in the camera shake frequency band are required. Therefore, the influence degree of induced magnetism affects the camera shake correction performance.

  FIG. 6 is a characteristic diagram showing the gain and phase of the open loop characteristic of the servo in the system shown in FIG. 5, and shows the difference between the case where there is an influence of induction magnetism by the drive coil 110 and the case where there is no influence. In FIG. 6, the point where the gain becomes 0 dB is referred to as a gain intersection, and the difference from −180 deg in the phase of the frequency at the gain intersection is referred to as a phase margin. Further, the amount of decrease in gain from 0 dB at a frequency where the phase characteristic crosses −180 deg is referred to as gain margin. The smaller the gain margin and phase margin are, the more unstable the servo becomes, causing oscillation. When oscillation occurs, the moving magnet 120 oscillates at a certain frequency, making it difficult to perform proper camera shake correction.

  In FIG. 6, the frequency due to the hand shake of the user is mainly vibration with a frequency of about 3 to 20 Hz. Therefore, as shown in FIG. 6, by sufficiently increasing the gain in this frequency band, the response characteristic to camera shake is improved, and the moving magnet 120 (correction lens 124) can be moved to a desired position with high accuracy in a short time. Can be driven.

  On the other hand, components other than the above-mentioned frequency band are included in the frequency due to the user's camera shake, and as shown in FIG. 6, frequencies in the band of about 10 Hz to 1 kHz or more are mixed in the servo loop in FIG. As described with reference to FIG. 3, as an example, at a frequency of 100 Hz or higher, the output of the Hall element 130 includes the influence of induction magnetism.

  In FIG. 6, the gain when there is an influence of induction magnetism at a frequency of 100 Hz or more is indicated by a broken line, and the gain when there is no influence of induction magnetism is indicated by a thick solid line. As shown in FIG. 6, it can be seen that when there is an influence of induction magnetism, the gain margin amount is reduced compared with a case where there is no influence of induction magnetism, and oscillation tends to occur. Therefore, when vibration with a frequency of 100 Hz or more is mixed in the servo loop, the moving magnet 120 oscillates, and a situation in which a desired camera shake correction cannot be performed is assumed.

  Furthermore, as described above, the frequency due to camera shake is mainly in the band of about 3 to 20 Hz. However, if the gain of 20 Hz or less necessary for camera shake correction is increased, the frequency of the gain intersection also increases. However, when there is an influence of induced magnetism, if the gain intersection frequency is increased, the gain margin decreases, so the gain intersection frequency cannot be increased. For this reason, there is a limit in improving response characteristics and position accuracy of camera shake correction.

  For this reason, in the present embodiment, the correction coil 140 is driven when a frequency of a predetermined value or more is detected in the servo loop in FIG. Since the induced magnetism of the drive coil 110 can be canceled by driving the correction coil 140, as described in FIG. 4, the actual movement amount of the moving magnet 120 from the Hall element 130 even in the high frequency region. A value proportional to is output. Therefore, it is possible to increase the gain margin in the servo loop, and it is possible to reliably prevent the occurrence of oscillation.

  FIG. 7 is a block diagram showing a configuration for driving the correction coil 140. The configuration shown in FIG. 7 corresponds to the block of the driver circuit 312 and the actuator 313 shown in FIG. As shown in FIG. 7, the output of the driver circuit 312 is input to the drive coil 110 and the correction circuit 320. The drive coil 110 is driven in response to an input from the driver circuit 312.

  When the correction circuit 320 extracts a signal in a frequency band that affects the servo band (for example, a frequency equal to or higher than the inflection point shown in FIG. 3), the correction circuit 320 cancels the magnetic polarity of the induced magnetism applied to the Hall element 130. The coil 140 is driven. Thereby, the induction magnetism is canceled, and the Hall element 130 can detect only the change in the magnetic field due to the movement of the moving magnet 120. Therefore, a stable servo loop with a sufficient gain margin can be realized, which is equivalent to the state without the influence of induction magnetism in FIG.

  As the correction circuit 320, a high-pass filter, a band-pass filter, or the like that extracts a frequency band above the inflection point can be used. The correction circuit 320 does not drive the correction coil 140 when it does not detect the frequency above the inflection point. Accordingly, in this case, only the drive coil 110 is driven. At frequencies below the inflection point, the influence of induction magnetism does not occur on the output of the Hall element 130, so that it is possible to detect the exact position of the moving magnet 120 without driving the correction coil 140.

  FIG. 8 and FIG. 9 are schematic diagrams showing configurations of the drive coil 110, the moving magnet 120, the Hall element 130, and the correction coil 140. As a method of canceling the induction magnetism of the drive coil 110, the induction coil in the direction opposite to the induction magnetism of the drive coil 110 is adapted by adjusting the coil winding direction or circuit polarity between the drive coil 110 and the correction coil 140. Is generated from the correction coil 140.

  In the configuration example shown in FIG. 8, the correction coil 140 is configured using the same coil as the drive coil 110. Then, the drive coil 110 and the correction coil 140 are arranged in opposite directions with the hall element 130 interposed therebetween, and are arranged at the equidistance d. Accordingly, if the amount of current flowing through the drive coil 110 and the correction coil 140 is the same, the same induction magnetism is generated from the drive coil 110 and the correction coil 140. Therefore, it is possible to cancel the induced magnetism by reversing the winding direction of the drive coil 110 and the correction coil 140.

  In the configuration example shown in FIG. 9, the correction coil 140 having a size smaller than that of the drive coil 110 is used in consideration of space efficiency. In the configuration example shown in FIG. 9, the specification of the correction coil 140 is changed so that the induction magnetism can be canceled on the Hall element 130, and the Hall element 130 and the correction coil 140 are made closer than those in FIG. 8. In this case, the induction magnetism can be canceled by optimizing the amount of current flowing through the correction coil 140, the coil specifications, and the distance from the Hall element 130. When the correction coil 140 is brought closer to the Hall element 130, the induction magnetism of the correction coil 140 on the Hall element 130 becomes larger. Therefore, it is possible to use the correction coil 140 that is smaller than that in FIG. Become. For example, the number of turns of the correction coil 140 can be made smaller than the number of turns of the drive coil 110. Further, when the correction coil 140 is brought closer to the Hall element 130, the induction magnetism of the correction coil 140 on the Hall element 130 becomes larger, so that the coil current can be reduced and the power consumption of the correction coil 140 can be suppressed. it can. In the configuration example shown in FIG. 9, the correction circuit 320 also includes a gain adjustment function for optimizing the amount of current flowing through the correction coil 140. In the configuration example of FIG. 9, when the magnetic force of the moving magnet 120 has reached the correction coil 140 by bringing the correction coil 140 close to the Hall element 130, the force that drives the moving magnet 120 by the correction coil 140 is increased. appear. In this case, since the winding directions of the drive coil 110 and the correction coil 140 are opposite, the force for driving the moving magnet 120 by the correction coil 140 is opposite to the force for driving the moving magnet 120 by the drive coil 110. , The power will cancel out. In order to avoid such a situation, a yoke (iron plate) is attached to the surface of the moving magnet 120 on the correction coil 140 side (not shown in FIG. 9). Thereby, since the magnetic flux of the moving magnet 120 does not leak to the correction coil side 140 by the yoke, it is possible to reliably prevent the correction coil 140 from generating a force that drives the moving magnet 120.

  In addition, variations in the induced magnetic field on the Hall element 130 that may occur during manufacture can be compensated by adjusting the distance between the drive coil 110 and the correction coil 140, adjusting the coil current value, and the like.

  As described above, according to the present embodiment, when the frequency at which the influence of the induction magnetism appears on the output of the Hall element 130 is detected in the servo loop, the correction magnet 140 is driven to cancel the induction magnetism. The position of the moving magnet 120 can be detected with high accuracy. Therefore, in the camera shake correction system, it is possible to stably control the servo loop, and it is possible to reliably prevent the servo from oscillating.

  The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 100 Camera shake correction apparatus 110 Drive coil 120 Moving magnet 124 Correction lens 130 Hall element 140 Correction coil 200 Imaging device 202 Imaging element 320 Correction circuit

Claims (10)

A drive actuator having a magnetic coil and driving a moving member for correcting camera shake by magnetic force;
A magnetic sensor for detecting the position of the moving member;
A correction actuator having a magnetic coil and disposed opposite to the drive actuator with the magnetic sensor interposed therebetween;
A drive circuit that drives the correction actuator when the drive signal of the drive actuator includes a frequency component equal to or higher than a predetermined value;
A camera shake correction device comprising:   The camera shake correction apparatus according to claim 1, wherein the predetermined value is a frequency at which an inflection point is generated in the output of the magnetic sensor due to induction magnetism of the drive actuator. The drive actuator and the correction actuator are arranged at equidistant positions from the magnetic sensor,
The camera shake correction device according to claim 1, wherein the magnetic coil of the correction actuator has the same specifications as the magnetic coil of the drive actuator, and a winding direction of the coil is reverse.   The distance between the correction actuator and the magnetic sensor is shorter than the distance between the drive actuator and the magnetic sensor, and the current value flowing through the magnetic coil of the correction actuator is the current flowing through the magnetic coil of the drive actuator. The camera shake correction apparatus according to claim 1, wherein the camera shake correction apparatus is smaller than the value.   The distance between the correction actuator and the magnetic sensor is shorter than the distance between the drive actuator and the magnetic sensor, and the number of turns of the magnetic coil of the correction actuator is less than the number of turns of the magnetic coil of the drive actuator. The camera shake correction device according to claim 1, wherein: An image sensor on which a subject image is formed;
A correction lens for correcting camera shake or a drive actuator for driving the image sensor with a magnetic force, and a magnetic coil;
A magnetic sensor for detecting a position of a magnet driven together with the correction lens or the imaging element;
A correction actuator having a magnetic coil and disposed opposite to the drive actuator with the magnetic sensor interposed therebetween;
A drive circuit that drives the correction actuator when the drive signal of the drive actuator includes a frequency component equal to or higher than a predetermined value;
An imaging apparatus comprising:   The imaging apparatus according to claim 6, wherein the predetermined value is a frequency at which an inflection point is generated in the output of the magnetic sensor due to induction magnetism of the drive actuator. The drive actuator and the correction actuator are arranged at equidistant positions from the magnetic sensor,
The imaging apparatus according to claim 6, wherein the magnetic coil of the correction actuator has the same specifications as the magnetic coil of the drive actuator, and a winding direction of the coil is reverse.   The distance between the correction actuator and the magnetic sensor is shorter than the distance between the drive actuator and the magnetic sensor, and the current value flowing through the magnetic coil of the correction actuator is the current flowing through the magnetic coil of the drive actuator. The imaging apparatus according to claim 6, wherein the imaging apparatus is smaller than the value.   The distance between the correction actuator and the magnetic sensor is shorter than the distance between the drive actuator and the magnetic sensor, and the number of turns of the magnetic coil of the correction actuator is less than the number of turns of the magnetic coil of the drive actuator. The imaging apparatus according to claim 6, wherein:

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