JP2010266739A - Vibration proof actuator and lens unit comprising the same and camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vibration proof actuator capable of movably supporting an image-shake correcting lens, without backlashes, using a simple constitution. <P>SOLUTION: The vibration proof actuator (10) for moving an image-shake preventing lens includes: a fixed part (12); a movable part (14) with an image shake preventing lens mounted; a support arm (17) for linking the movable part and the fixed part for preventing inclination of the movable part with respect to the optical axis, while permitting movement of the movable part; a spherical body (18), held between the movable part and the fixed part; a first driving means, having a first driving magnet (22a) and a first driving coil (20a) disposed facing thereto for driving the movable part, with respect to the fixed part, and a second driving means having a second driving magnet (22b) and a second driving coil (20b), disposed facing thereto for generating a driving force, in a direction which is substantially orthogonal to the driving force of the first driving means. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an anti-vibration actuator, and more particularly to an anti-vibration actuator that moves an image blur prevention lens within a plane orthogonal to the optical axis thereof, and a lens unit and a camera including the same.

  Japanese Patent Laying-Open No. 2007-233140 (Patent Document 1) describes an image blur correction apparatus. In this image blur correction apparatus, the first and second linear motors and the image blur correction lens are arranged in a straight line, and the support frame to which the image blur correction lens is attached is driven in the horizontal direction and the vertical direction. . The support frame to which the image blur correction lens is attached is movably supported by two support bars that allow vertical movement and two support bars that allow horizontal movement. In this image blur correction device, since the first and second linear motors and the image blur correction lenses are arranged in a straight line in the horizontal direction, the overall width of the image blur correction device is narrow. There is an advantage that can be.

JP 2007-233140 A

  However, the image blur correction apparatus described in Japanese Patent Application Laid-Open No. 2007-233140 has a problem in that since the support frame slides along the support rod, the sliding resistance is large and a large driving force is required. In this image blur correction apparatus, a horizontal support rod is attached to a member supported by two support rods oriented in the vertical direction, and an image blur correction lens is mounted along the horizontal support rod. Since the attached support frame is configured to slide, there is a problem in that it is difficult to accurately hold the image blur correction lens due to the added backlash of the sliding portion. Further, this image blur correction apparatus requires two sets of support rods, and there is a problem that the structure becomes complicated.

Accordingly, an object of the present invention is to provide a vibration-proof actuator capable of movably supporting an image blur correction lens with a simple structure, and a lens unit and a camera including the same.
Another object of the present invention is to provide an anti-vibration actuator that can be configured with a narrow overall width, and a lens unit and a camera including the same.

  In order to solve the above-described problems, the present invention provides an image stabilization actuator that moves an image stabilization lens within a plane perpendicular to the optical axis, and includes a fixed portion and an image stabilization lens. The movable part and a single part that connects the movable part and the fixed part so as to prevent the movable part from being inclined with respect to the optical axis while allowing movement of the movable part in a plane orthogonal to the optical axis. A support arm, a spherical body that is sandwiched between the movable part and the fixed part and allows movement of the movable part while maintaining a distance between the movable part and the fixed part, and a first driving magnet and the first driving magnet and the spherical body A first driving means for driving the movable part with respect to the fixed part, a second driving magnet, and a second driving coil arranged so as to face the first driving coil. The driving force in a direction substantially perpendicular to the driving force of one driving means It is characterized by having a second driving means for raw, the.

  In the present invention configured as described above, the movable portion to which the image blur prevention lens is attached is connected to the fixed portion by one support arm. Further, the spherical body sandwiched between the movable part and the fixed part allows the movement of the movable part while maintaining the distance between the movable part and the fixed part. The first driving means and the second driving means drive the movable part relative to the fixed part.

  According to the present invention configured as described above, since the movable part to which the image blur prevention lens is attached is supported by the support arm and the spherical body with respect to the fixed part, the image blur correction can be performed with a simple structure and without play. The lens can be movably supported.

  In the present invention, preferably, the movable portion is formed to be thin, and the image blur prevention lens, the first drive unit, and the second drive unit are arranged in the longitudinal direction of the movable unit. They are arranged side by side in the order of the second drive means.

  According to the present invention configured as described above, the first drive unit, the image blur prevention lens, and the second drive unit are arranged side by side in the longitudinal direction of the movable portion, so that the width of the vibration isolation actuator is reduced. Can be formed.

  In the present invention, preferably, the support arm is connected to one end portion in the longitudinal direction of the movable portion, and the first driving means disposed adjacent to the support arm is configured to drive the movable portion in the substantially longitudinal direction. Generate power.

  According to the present invention configured as described above, the second driving means located away from the support arm generates a driving force in a direction substantially perpendicular to the longitudinal direction of the movable part. The center can be rotated by a small driving force of the second driving means.

  In the present invention, preferably, the support arm is connected to one end portion in the longitudinal direction of the movable portion and is arranged to extend in a direction crossing the longitudinal direction of the movable portion.

  According to the present invention configured as described above, since the support arm is arranged so as to extend in a direction transverse to the longitudinal direction of the movable portion, the support arm can be image-blurred without increasing the width of the vibration-proof actuator. The anti-vibration actuator can be configured to allow the correction lens to move in the horizontal and vertical directions.

In the present invention, the support arm is preferably connected to the movable part and the fixed part so as to be rotatable in a plane perpendicular to the optical axis.
According to the present invention configured as described above, it is possible to effectively move the movable part from being inclined with respect to the optical axis while allowing the movable part to be moved with a small driving force in a plane orthogonal to the optical axis. can do.

  In the present invention, preferably, the support arm is configured to allow movement of the movable portion by being elastically deformed, and has low rigidity against deformation that moves the movable portion in a plane orthogonal to the optical axis. The movable portion is formed with high rigidity against the movement inclined with respect to the optical axis.

  According to the present invention configured as described above, since the movement of the movable portion is allowed by the elastic deformation of the support arm, the play of the support mechanism can be extremely reduced. In addition, the support arm is formed with low rigidity for deformation that moves the movable part in a plane orthogonal to the optical axis, and high rigidity for movement where the movable part is inclined with respect to the optical axis. The movable part can be moved with a small driving force, and the inclination of the movable part with respect to the optical axis can be effectively suppressed.

  The lens unit of the present invention includes a lens barrel, an imaging lens disposed in the lens barrel, and the vibration-proof actuator of the present invention attached to the lens barrel. Yes.

  Furthermore, the camera of the present invention includes a housing, an imaging lens disposed in the housing, and the vibration-proof actuator of the present invention attached to the housing.

According to the vibration-proof actuator of the present invention, and the lens unit and camera including the same, the image blur correction lens can be supported movably with a simple structure.
Moreover, according to the vibration-proof actuator of the present invention, and the lens unit and camera including the same, the overall width can be reduced.

FIG. 1 is a cross-sectional view of a camera according to an embodiment of the present invention. It is a front view of the vibration proof actuator built in the camera by the embodiment of the present invention. It is sectional drawing which follows the III-III line | wire of a vibration proof actuator. It is a perspective view of the support arm currently used for the vibration proof actuator. It is a block diagram which shows the signal processing in a controller. It is sectional drawing of the vibration proof actuator by a modification.

Next, a camera according to an embodiment of the present invention will be described with reference to the accompanying drawings.
First, a camera according to an embodiment of the present invention will be described with reference to FIGS. 1 to 5. FIG. 1 is a cross-sectional view of a camera according to an embodiment of the present invention.
As shown in FIG. 1, a camera 1 according to an embodiment of the present invention includes a housing 2, a plurality of imaging lenses 8 arranged in a lens barrel portion of the housing 2, and an image blur prevention lens. The anti-vibration actuator 10 which moves 16 within a predetermined plane, and the gyros 34a and 34b (only 34a is shown in FIG. 1) which are the vibration detection means which detects the vibration of the camera 1 are provided.

  The camera 1 according to the embodiment of the present invention detects vibrations by the gyros 34 a and 34 b, operates the image stabilization actuator 10 based on the detected vibrations to move the image stabilization lens 16, and The image focused on the imaging element surface F is stabilized. In the present embodiment, piezoelectric vibration gyros are used as the gyros 34a and 34b. In the present embodiment, the image blur prevention lens 16 is constituted by a single lens, but the lens for stabilizing the image may be a plurality of lens groups. In this specification, the image blur prevention lens includes one lens and a lens group for stabilizing an image.

  The plurality of imaging lenses 8 are attached to the casing 2 and configured to form incident light on the imaging element surface F. Further, focus adjustment can be performed by moving some of the plurality of imaging lenses 8.

  Next, the vibration-proof actuator 10 will be described with reference to FIGS. FIG. 2 is a front view of the vibration-proof actuator 10. FIG. 3 is a cross-sectional view of the vibration-proof actuator 10 taken along line III-III. FIG. 4 is a perspective view of a support arm used in the vibration proof actuator 10.

  As shown in FIGS. 1 to 4, the vibration isolation actuator 10 is supported so as to be movable in a plane parallel to the fixed plate 12 and a fixed plate 12 that is fixed to the housing 2. The movable frame 14 that is a movable part, the support arm 17 that couples the fixed plate 12 and the movable frame 14, and the steel ball 18 that is a spherical body sandwiched between the movable frame 14 and the fixed plate 12. Further, the vibration isolation actuator 10 is attached to the first driving coil 20a and the second driving coil 20b attached to the fixed plate 12, and the moving frame 14 at positions corresponding to the respective driving coils 20a and 20b. The first driving magnet 22a, the second driving magnet 22b, and the first magnetic sensor 24a and the second magnetic sensor 24a, which are first and second position detecting elements, disposed inside the driving coils 20a and 20b, respectively. And a magnetic sensor 24b.

  Further, the vibration-proof actuator 10 includes two suction yokes 26 attached to the back side of the fixed plate 12 and each drive magnet in order to draw the moving frame 14 toward the fixed plate 12 by the magnetic force of each drive magnet. The back yoke 28 for effectively directing the magnetism toward the fixed plate 12 is provided. The first drive coil 20a, the second drive coil 20b, and the first drive magnet 22a and the second drive magnet 22b respectively attached to the corresponding positions of the first drive coil 20a, the second drive coil 20b, and the movable plate 14 are fixed to the fixed plate 12. The first and second driving means for driving each are configured.

  Further, as shown in FIG. 1, the vibration isolation actuator 10 is based on the vibration detected by the gyros 34a and 34b and the position information of the moving frame 14 detected by the first and second magnetic sensors 24a and 24b. It has the controller 36 which is a control part which controls the electric current sent through the 1st, 2nd drive coils 20a and 20b.

  The anti-vibration actuator 10 translates the moving frame 14 in a plane parallel to the imaging element surface F with respect to the fixed plate 12 fixed to the housing 2, thereby preventing image blur attached to the moving frame 14. Even if the camera lens 16 is moved and the camera 1 vibrates, it is driven so that the image formed on the imaging element surface F is not disturbed.

  The fixed plate 12 has a substantially rectangular shape, and the first and second drive coils 20a and 20b are disposed thereon. As shown in FIG. 2, these two driving coils are respectively disposed on both sides of the image blur prevention lens 16. In the present embodiment, the first driving coil 20a is disposed on the left side of the prevention lens 16 to generate a horizontal driving force, and the second driving coil 20b is disposed on the right side of the prevention lens 16 to be vertical. It is comprised so that the driving force of this may be generated. Further, the support arm 17 is disposed on the left side of the first drive coil 20a to connect the fixed plate 12 and the moving frame 14, and the steel ball 18 is disposed on the right side of the second drive coil 20b to be fixed to the fixed plate 12. It is sandwiched between the moving frames 14. Therefore, in the present embodiment, in order from the left in FIG. 2, the support arm 17, the first drive coil 20 a, the prevention lens 16, the second drive coil 20 b, and the steel ball 18 are attached to the fixed plate 12 and the moving frame 14. They are arranged in a substantially straight line in the longitudinal direction.

  The first and second drive coils 20a and 20b are wound in a rectangular shape with rounded corners. The first and second drive coils 20a and 20b are substantially rectangular, and are arranged so that the center lines crossing the long sides thereof coincide with the X axis (horizontal axis) and the Y axis (vertical axis), respectively. Yes.

  The moving frame 14 has a long and generally rectangular shape, and is arranged in parallel with the fixed plate 12. An image blur prevention lens 16 is attached to the opening at the substantially center of the moving frame 14. In the moving frame 14, first and second driving magnets 22a and 22b are arranged at positions corresponding to the first and second driving coils 20a and 20b, respectively. The first and second drive magnets 22a and 22b have a substantially rectangular shape, and are arranged so that each side is parallel to the X axis and the Y axis, respectively. The first and second drive magnets 22a and 22b are magnetized so that the center line crossing the long side becomes a magnetization boundary line. That is, the magnetization boundary line of the first drive magnet 22a is directed in the vertical direction, and the magnetization boundary line of the second drive magnet 22b is directed in the horizontal direction.

  As shown in FIG. 2, the support arm 17 is attached so as to connect an end portion on the left side in the longitudinal direction of the moving frame 14 and an arm attachment portion 12 a formed integrally with the fixed plate 12. The support arm 17 is fixed to the upper end of the short side of the moving frame 14 and is arranged to extend substantially vertically downward, that is, in a direction crossing the longitudinal direction of the moving frame 14. Further, the connecting portion of the support arm 17 and the moving frame 14 and the connecting portion of the support arm 17 and the fixed plate 12 are generally located in a plane orthogonal to the optical axis A. In other words, the support arm 17 extends in a direction substantially orthogonal to the optical axis A.

  As shown in FIG. 4, the support arm 17 has a rectangular thin plate-like flexible portion 17a and a diameter larger than the thickness of the flexible portion 17a provided at both ends of the flexible portion 17a. Column-shaped fixing portions 17b and 17c. With this structure, the support arm 17 is easily elastically deformed into the first form in which the thin plate-like flexible portion 17a is bent while the fixing portions 17b and 17c are maintained in parallel, but each fixing portion 17b, It cannot be easily deformed to the second configuration in which 17c is non-parallel in the plane of the flexible portion 17a.

  The fixed portion 17b is rigidly fixed to the moving frame 14, the fixed portion 17c is rigidly fixed to the arm attachment portion 12a, and the flexible portion 17a is elastically deformed to the first form. The movement of the moving frame 14 with respect to the fixed plate 12 is allowed. Further, as shown in FIG. 2, the thin plate-like flexible portion 17 a is disposed so that the plate surface thereof is directed parallel to the optical axis A. For this reason, the moving frame 14 can be easily moved in a plane orthogonal to the optical axis A. On the other hand, since the flexible portion 17a is not easily deformed to the second form, the moving frame 14 is not perpendicular to the optical axis A, that is, the moving frame 14 is inclined to the optical axis A. It is prevented from being moved.

  As shown in FIGS. 2 and 3, the steel ball 18 is sandwiched between the fixed plate 12 and the moving frame 14, and is disposed at the end of the fixed plate 12 and the moving frame 14 opposite to the support arm 17. ing. The steel ball 18 is disposed in a circumferential wall 30 formed at a position corresponding to the steel ball 18 of the fixing plate 12 and is prevented from falling off. One end of the fixed plate 12 and the moving frame 14 are connected by a support arm 17, and the steel ball 18 is sandwiched between the other ends so that the distance between them is kept constant. As a result, the moving frame 14 is supported on a plane parallel to the fixed plate 12, rolls while the steel ball 18 is held, and the support arm 17 is elastically deformed, whereby the moving frame 14 is fixed to the fixed plate 12. Translational motion is allowed.

  Although the moving frame 14 is supported by one steel ball 18, the support arm 17 has high rigidity against deformation in the direction in which the moving frame 14 tilts as described above. The inclination with respect to is effectively suppressed.

  In the present embodiment, a steel sphere is used as the steel ball 18, but a resin sphere can be used instead of the steel ball 18. Further, the steel ball 18 is not necessarily a sphere. In other words, the steel ball 18 can be used as long as the portion in contact with the fixed plate 12 and the moving frame 14 has a substantially spherical shape during the operation of the vibration isolating actuator 10. In addition, in this specification, such a form is called a spherical body.

  The suction yoke 26 has a substantially rectangular shape, and is attached to a position corresponding to each drive coil on the surface of the fixed plate 12 on which the drive coil is not attached. The moving frame 14 is attracted toward the fixed plate 12 by the magnetic force exerted by each driving magnet on the attracting yoke 26.

  As shown in FIG. 3, the magnetization boundary line C of the first drive magnet 22a is positioned so as to pass through the midpoint of each long side of the rectangular first drive magnet 22a, and the first drive magnet 22a. The polarity also changes in the thickness direction. In the present embodiment, the lower left corner in FIG. 3 is the S pole, the lower right is the N pole, the upper left is the N pole, and the upper right is the S pole. The second driving magnet 22b is similarly magnetized, and the direction of attachment to the moving frame 14 is rotated by 90 ° (FIG. 2). In this specification, the magnetization boundary line C is a line connecting points where the polarity changes from the S pole in the middle to the N pole when both ends of the driving magnet are set to S pole and N pole, respectively. Say it.

  By being magnetized in this way, the first and second drive magnets 22a and 22b exert magnetism on the long sides of the rectangular first and second drive coils 20a and 20b. Thus, when a current flows through the first driving coil 20a, a horizontal driving force along the X axis is generated between the first driving magnet 22a and a current flows through the second driving coil 20b. A vertical driving force along the Y axis is generated between the second driving magnet 22b.

  That is, the driving force by the first driving means constituted by the first driving coil 20a and the first driving magnet 22a is directed in the horizontal direction, and is constituted by the second driving coil 20b and the second driving magnet 22b. The driving force by the second driving means is substantially perpendicular to the direction of the driving force by the first driving means and is directed in the vertical direction.

  Here, the moving frame 14 is connected to the fixed plate 12 by the support arm 17, but the moving amount of the moving frame 14 necessary for correcting the image blur is the size of the moving frame 14 and the support arm 17. Therefore, the moving frame 14 is approximately translated in the horizontal direction and the vertical direction by the driving force of the first driving means and the second driving means. That is, when the horizontal driving force by the first driving means is applied, the flexible arm 17a is elastically deformed so that the support arm 17 is displaced in the horizontal direction while the fixing portions 17b and 17c are kept parallel, Horizontal translation is allowed.

  On the other hand, when a vertical driving force is applied by the second driving means, the support arm 17 is elastically deformed so that the moving frame 14 is rotated around the vicinity of the flexible portion 17a. However, the moving distance in the vertical direction of the image blur prevention lens 16 necessary for correcting the image blur is extremely small with respect to the distance between the support arm 17 and the image blur prevention lens 16, and thus the moving frame 14. The angle at which is rotated is very small. For this reason, the movement of the image blur prevention lens 16 caused by the rotation of the moving frame 14 can be approximately regarded as a translational movement in the vertical direction. As described above, the image blur prevention lens 16 is translated by a driving force generated by the first driving unit and the second driving unit with a sufficient range and accuracy necessary for correcting the image blur.

  As shown in FIGS. 2 and 3, a first magnetic sensor 24a and a second magnetic sensor 24b are arranged inside each driving coil, respectively. The first and second magnetic sensors 24a and 24b are configured to measure the position of the moving frame 14 with respect to the fixed plate 12 in a direction parallel to the driving force generated by the first and second driving means. Further, each magnetic sensor is arranged such that the sensitivity center point thereof is located on the magnetization boundary line C of each driving magnet 22 when the moving frame 14 is in the neutral position. In the present embodiment, a Hall element is used as the magnetic sensor.

  The output signal from the magnetic sensor is 0 when the sensitivity center point of the magnetic sensor is located on the magnetization boundary line C of the driving magnet, the driving magnet moves, and the magnetic sensor sensitivity center point is for driving. When it deviates from the magnetized boundary line C, the output signal of the magnetic sensor changes. During the normal operation of the vibration isolation actuator 10 in which the amount of movement of the driving magnet is very small, a signal substantially proportional to the moving distance in the direction orthogonal to the magnetization boundary line C of the driving magnet is output.

  Therefore, the first magnetic sensor 24a outputs a signal that is substantially proportional to the translational movement amount of the moving frame 14 in the X-axis direction, and the second magnetic sensor 24b is substantially proportional to the translational movement amount of the moving frame 14 in the Y-axis direction. Output a signal. Based on the signals detected by the first and second magnetic sensors 24a and 24b, the position where the moving frame 14 is translated relative to the fixed plate 12 can be specified with sufficient accuracy.

  Next, control of the vibration isolation actuator 10 will be described with reference to FIG. FIG. 5 is a block diagram showing signal processing in the controller 36. As shown in FIG. 5, the vibration of the camera 1 is detected from time to time by the two gyros 34 a and 34 b and input to the arithmetic circuits 38 a and 38 b built in the controller 36. In the present embodiment, the gyro 34a is configured and arranged to detect the angular velocity of the yawing motion of the camera 1, and the gyro 34b is configured to detect the angular velocity of the pitching motion.

  The arithmetic circuits 38a and 38b generate lens position command signals for instructing in time series the position at which the image blur prevention lens 16 should be moved based on the angular velocities input from the gyros 34a and 34b every moment. That is, the arithmetic circuit 38a time-integrates the angular velocity of the yawing motion detected by the gyro 34a and adds a predetermined correction signal to generate a horizontal component of the lens position command signal. Similarly, the arithmetic circuit 38b The vertical component of the lens position command signal is generated based on the angular velocity of the pitching motion detected by the gyro 34b. By moving the image blur prevention lens 16 momentarily according to the lens position command signal obtained in this way, even when the camera 1 vibrates during exposure of photography, the image sensor surface F is focused. The image is stabilized without being disturbed.

  The controller 36 causes the first and second drive coils 20a and 20b to flow so that the image blur prevention lens 16 is moved to the position instructed by the lens position command signal generated by the arithmetic circuits 38a and 38b. Control the current.

  On the other hand, the amount of horizontal movement of the first drive magnet 22a relative to the first drive coil 20a measured by the first magnetic sensor 24a is amplified to a predetermined magnification by the magnetic sensor amplifier 42a. The differential circuit 44a includes a horizontal component of the lens position command signal output from the arithmetic circuit 38a, and a horizontal movement amount of the first driving magnet 22a relative to the first driving coil 20a output from the magnetic sensor amplifier 42a. A current proportional to the difference is passed through the first drive coil 20a. Accordingly, when there is no difference between the horizontal component of the lens position commanded by the lens position command signal and the output from the magnetic sensor amplifier 42a, no current flows through the first drive coil 20a, and the first drive magnet 22a The applied driving force becomes zero.

  Similarly, the amount of vertical movement of the second drive magnet 22b relative to the second drive coil 20b measured by the second magnetic sensor 24b is amplified to a predetermined magnification by the magnetic sensor amplifier 42b. The differential circuit 44b includes a vertical component of the lens position command signal output from the arithmetic circuit 38b, and a vertical movement amount of the second drive magnet 22b relative to the second drive coil 20b output from the magnetic sensor amplifier 42b. A current proportional to the difference is passed through the second drive coil 20b. Accordingly, when there is no difference between the vertical direction component of the lens position commanded by the lens position command signal and the output from the magnetic sensor amplifier 42b, no current flows through the second driving coil 20b and acts on the driving magnet 22b. The driving force becomes zero.

  Next, the operation of the camera 1 according to the embodiment of the present invention will be described with reference to FIGS. First, by turning on a start switch (not shown) for the camera shake prevention function of the camera 1, the vibration isolation actuator 10 is operated. Gyroes 34 a and 34 b built in the camera 1 detect vibrations in a predetermined frequency band every moment and output them to arithmetic circuits 38 a and 38 b built in the controller 36. The gyro 34a outputs an angular velocity signal in the yawing direction of the lens unit 2 to the arithmetic circuit 38a, and the gyro 34b outputs an angular velocity signal in the pitching direction to the arithmetic circuit 38b. The arithmetic circuit 38a integrates the input angular velocity signal with time to calculate the yawing angle, and adds a predetermined correction signal to this to generate a horizontal lens position command signal. Similarly, the arithmetic circuit 38b integrates the input angular velocity signal with time to calculate a pitching angle, and adds a predetermined correction signal to this to generate a vertical lens position command signal. An image focused on the imaging element surface F of the camera 1 by moving the image blur prevention lens 16 momentarily to a position commanded by a lens position command signal output in time series by the arithmetic circuits 38a and 38b. Is stabilized.

  The horizontal lens position command signal output by the arithmetic circuit 38a is input to the differential circuit 44a, and the vertical lens position command signal output by the arithmetic circuit 38b is input to the differential circuit 44b.

  On the other hand, the first magnetic sensor 24a arranged inside the first driving coil 20a outputs a detection signal to the magnetic sensor amplifier 42a, and the second magnetic sensor 24b inside the second driving coil 20b outputs the detection signal to the magnetic sensor amplifier 42b. To do. The detection signals of the magnetic sensors amplified by the magnetic sensor amplifiers 42a and 42b are input to the differential circuits 44a and 44b, respectively.

  Each of the differential circuits 44a and 44b generates a voltage corresponding to the difference between the input detection signal of each magnetic sensor and the signal input from each arithmetic circuit 38a and 38b, and drives each current in proportion to this voltage. Flow through the coil. When a current flows through each driving coil, a magnetic field proportional to the current is generated. Due to this magnetic field, the first and second drive magnets 22a and 22b arranged corresponding to the first and second drive coils 20a and 20b respectively receive drive force, and the moving frame 14 is moved. When the moving frame 14 is moved by the driving force and each driving magnet reaches the position specified by the lens position command signal, the output of each differential circuit becomes 0 and the driving force also becomes 0. Further, when the moving frame 14 moves out of the position specified by the lens position command signal due to a disturbance or a change in the lens position command signal, a current is again supplied to each driving coil, and the moving frame 14 Returns to the position specified by the signal.

  By repeating the above operation every moment, the image blur prevention lens 16 attached to the moving frame 14 is moved so as to follow the lens position command signal. Thereby, the image focused on the imaging element surface F of the camera 1 is stabilized.

  According to the camera of the embodiment of the present invention, the moving frame to which the image blur prevention lens is attached is supported by the support arm and the steel ball with respect to the fixed plate. The lens can be movably supported.

  Further, according to the camera of the present embodiment, the first driving means, the image blur prevention lens, and the second driving means are arranged substantially in a straight line in the longitudinal direction of the moving frame. Can be formed small.

  Further, according to the camera of the present embodiment, the second driving means located at a position away from the support arm generates a driving force in a direction substantially perpendicular to the longitudinal direction of the moving frame. The center can be rotated by a small driving force of the second driving means.

  Further, according to the camera of the present embodiment, since the support arm is arranged so as to extend in the direction crossing the longitudinal direction of the moving frame, the support arm can perform image blur correction without increasing the width of the vibration isolation actuator. The anti-vibration actuator can be configured to allow horizontal movement and vertical movement of the lens for use.

  Furthermore, according to the camera of the present embodiment, the movement of the moving frame is allowed by elastic deformation of the flexible portion of the support arm, so that the backlash of the support mechanism can be extremely reduced. In addition, the flexible portion of the support arm has low rigidity for deformation that moves the moving frame in a plane orthogonal to the optical axis, and high rigidity for movement in which the moving frame is inclined with respect to the optical axis. Since it is formed, the moving frame can be moved with a small driving force, and the inclination of the moving frame with respect to the optical axis can be effectively suppressed.

  Further, in the above-described embodiment, the support arm is configured by the fixed portion fixed to the fixed plate and the moving frame and the flexible portion extending therebetween, but as a modified example, the support arm is fixed. The connecting portions connected to the plate and the moving frame can be made flexible, and the rigidity of the main body portion of the support arm connecting the connecting portions can be increased.

  Furthermore, in the above-described embodiment, the magnetic sensor for measuring the position of the driving magnet is arranged inside the driving coil. However, as a modification, as shown in FIG. It can also be arranged on the opposite side. In this modification, a driving coil 120a and a magnetic sensor 124a are arranged on both sides of a driving magnet 122a attached to the moving frame. That is, the driving coil 120a is fixed to the fixed plate 112 at a position corresponding to the driving magnet 122a, and the second fixing plate 112a arranged on the opposite side of the driving magnet 122a is connected to the driving magnet 122a. The magnetic sensor 124a is fixed at the corresponding position. Further, a back yoke 128 is disposed on the back side of the second fixing plate 112a at a position corresponding to the magnetic sensor 124a.

  In this modification, a driving force is applied to the driving magnet 122a when a current flows through the driving coil 120a, and the position of the driving magnet 122a is a magnetic sensor 124a disposed on the opposite side of the driving coil 120a. Is detected. According to this modification, it is possible to suppress the magnetic field generated by the driving coil 120a from affecting the detection result of the magnetic sensor 124a.

  As mentioned above, although preferable embodiment of this invention was described, a various change can be added to embodiment mentioned above. In particular, in the above-described embodiment, the image stabilization actuator of the present invention is built in the camera. However, the present invention is configured as a lens unit in which the image stabilization actuator and the imaging lens are arranged in a lens barrel. You can also

  Furthermore, in the above-described embodiment, the driving coil is attached to the fixed plate and the driving magnet is attached to the moving frame. However, the driving magnet can be attached to the fixed plate, and the driving coil can be attached to the moving frame. .

  In the above-described embodiment, the steel ball, which is one spherical body, is disposed between the fixed plate and the moving frame. However, a plurality of spherical bodies may be provided.

DESCRIPTION OF SYMBOLS 1 Camera by embodiment of this invention 2 Case 8 Imaging lens 10 Anti-vibration actuator 12 Fixed plate (fixed part)
14 Moving frame (movable part)
16 Lens for preventing image blur 17 Support arm 17a Flexible portion 17b, 17c Fixed portion 18 Steel ball (spherical body)
20a First drive coil 20b Second drive coil 22a First drive magnet 22b Second drive magnet 24a First magnetic sensor 24b Second magnetic sensor 26 Suction yoke 28 Back yoke 30 Circumferential walls 34a, 34b Gyro 36 Controller 38a, 38b arithmetic circuit 42a, 42b magnetic sensor amplifier 44a, 44b differential circuit

Claims (8)

An anti-vibration actuator that moves an image blur prevention lens in a plane perpendicular to the optical axis,
A fixed part;
A movable part to which the lens for preventing image blur is attached;
One connecting the movable part and the fixed part so as to prevent the movable part from tilting with respect to the optical axis while allowing the movable part to move in a plane orthogonal to the optical axis. A support arm of
A spherical body that is sandwiched between the movable part and the fixed part, and allows movement of the movable part while maintaining a distance between the movable part and the fixed part;
A first driving means including a first driving magnet and a first driving coil disposed so as to face the first driving magnet, and driving the movable portion relative to the fixed portion;
A second driving means comprising a second driving magnet and a second driving coil arranged to face the second driving magnet, and generating a driving force in a direction substantially perpendicular to the driving force of the first driving means;
An anti-vibration actuator comprising:   The movable part is formed in a thin shape, and the image blur prevention lens, the first drive means, and the second drive means are arranged in the longitudinal direction of the movable part, the first drive means, the image blur prevention lens, The anti-vibration actuator according to claim 1, wherein the anti-vibration actuators are arranged in order of the second drive means.   The support arm is connected to one end in the longitudinal direction of the movable part, and the first driving means disposed adjacent to the support arm generates a driving force in the longitudinal direction of the movable part. The vibration-proof actuator according to claim 2, which is generated.   4. The vibration-proof actuator according to claim 2, wherein the support arm is connected to one end in the longitudinal direction of the movable part and is disposed so as to extend in a direction crossing the longitudinal direction of the movable part.   The vibration-proof actuator according to any one of claims 1 to 4, wherein the support arm is connected to the movable portion and the fixed portion so as to be rotatable in a plane orthogonal to the optical axis.   The support arm is configured to allow movement of the movable part by being elastically deformed, and has low rigidity with respect to deformation that moves the movable part in a plane perpendicular to the optical axis. The vibration-proof actuator according to any one of claims 1 to 4, wherein the vibration-proof actuator is formed to have high rigidity with respect to movement of the portion inclined with respect to the optical axis. A lens barrel;
An imaging lens arranged in the lens barrel;
The vibration-proof actuator according to any one of claims 1 to 6, attached to the lens barrel,
A lens unit comprising: A housing,
An imaging lens arranged in the housing;
The vibration-proof actuator according to any one of claims 1 to 6, attached to the housing,
A camera characterized by comprising:

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