JP2015084035A - Vibration-proof actuator and lens unit including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibration-proof actuator that enables a movable part to be locked without increase in entire size.SOLUTION: A vibration-proof actuator (10) according to the present invention has: a securing part (12); a movable part (14) to which an image tremor proof lens (16) is attached; movable part support means (18) for movably supporting the movable part with respect to the securing part; drive means that includes a plurality of drive coils (20) and a plurality of drive magnets (22) arranged so as to face a plurality of drive coils, respectively, and, by magnetic force affecting between each drive coil and each drive magnetic, drives the movable part to the securing part and preventing an image tremor; a movable part lock mechanism (38) that mechanically locks the movable part at a prescribed position; and a lock coil (40) that is attached to the movable lock mechanism. The lock coil is configured to drive the movable lock mechanism into a standby state by the magnetic force affecting between the drive magnetic and the drive coil.

Description

  The present invention relates to an image stabilization actuator, and more particularly to an image stabilization actuator for moving an image stabilization lens, a lens unit including the same, and a camera.

  Japanese Patent No. 3397536 (Patent Document 1) describes a correction optical device. The correction optical device includes a correction lens that decenters the optical axis, and a lock ring that locks the correction lens. The lock ring has an annular shape surrounding the correction lens, and a cam portion that engages with the frame of the correction lens is formed on the inner periphery thereof. In this correction optical device, when the correction by the correction optical device is not performed, the lock ring surrounding the correction lens is rotated so that the cam portion formed on the inner periphery thereof and the outer peripheral portion of the frame of the correction lens are arranged. The correction lens is locked by engaging.

Japanese Patent No. 3397536

  However, in the locking mechanism of the type that rotates the lock ring as described in Japanese Patent No. 3397536, it is necessary to provide a locking actuator in addition to the actuator for driving the correction lens. For this reason, there exists a problem that the whole correction | amendment optical apparatus (anti-vibration actuator) enlarges.

  Accordingly, an object of the present invention is to provide an anti-vibration actuator capable of locking a movable portion without increasing the size of the entire anti-vibration actuator, and a lens unit and a camera including the same.

  In order to solve the above-described problems, the present invention provides a vibration-proof actuator for moving an image blur prevention lens, a fixed portion, a movable portion to which the image blur prevention lens is attached, and the movable portion. In a plane perpendicular to the optical axis of the image blur prevention lens so as to be movable with respect to the fixed portion, a plurality of drive coils, and these drive coils so as to face each other. A plurality of drive magnets arranged, a drive means for preventing image blur by driving the movable portion relative to the fixed portion by a magnetic force acting between each drive coil and each drive magnet; A movable portion locking mechanism that mechanically locks the portion at a predetermined position, and a locking coil attached to the movable portion locking mechanism. The locking coil is connected to the drive magnet. The movable part locking mechanism is locked by the magnetic force acting between them. It is characterized in that drive.

  In the present invention configured as described above, the movable portion to which the image blur prevention lens is attached is supported so as to be movable with respect to the fixed portion by the movable portion support means. The driving means includes a plurality of driving coils and a plurality of driving magnets disposed so as to oppose each other, and drives the movable portion relative to the fixed portion to execute image blur prevention control. . Further, the locking coil attached to the movable part locking mechanism drives the movable part locking mechanism into a locked state by a magnetic force acting between the driving magnets.

  According to the present invention configured as described above, the movable portion is driven by the magnetic force acting between the plurality of driving coils and the plurality of driving magnets, and image blur prevention control is executed. On the other hand, since the movable portion locking mechanism is driven by a magnetic force acting between the locking coil and the driving magnet, it is not necessary to provide a dedicated magnet for generating a magnetic force between the locking coil and the driving magnet. The entire vibration-proof actuator can be reduced in size.

In the present invention, preferably, the plurality of driving magnets are attached to the fixed portion, and the plurality of driving coils are attached to the movable portion.
According to the present invention configured as described above, the locking coil generates a driving force with the driving magnet attached to the fixed portion, so that the driving magnet is generated by a reaction force of the generated driving force. Is not moved, and the movable portion locking mechanism can be reliably driven.

  In the present invention, it is preferable that the movable portion locking mechanism includes an annular lock member that is rotatably arranged with respect to the movable portion and has a locking coil attached thereto, and the annular lock member is engaged with the drive magnet. The movable part is locked by being rotated by the magnetic force acting between the stop coils.

  According to the present invention configured as described above, since the movable portion is locked by the rotation of the annular lock member constituting the movable portion locking mechanism, the movable portion locking mechanism can be easily achieved by the locking coil. Can be driven.

  In the present invention, preferably, the annular lock member includes an abutting portion that comes into contact with the movable portion, and the annular lock member is rotated with respect to the movable portion so that the abutting portion and the movable portion of the annular lock member abut against each other. The moving part is locked.

  According to the present invention configured as above, the movable portion is locked by the contact portion of the annular lock member coming into direct contact with the movable portion, so that the movable portion locking mechanism is configured with a simple mechanism. be able to.

  In the present invention, preferably, the movable portion locking mechanism further includes at least three locking arms, and the locking arm is driven by rotating the annular lock member, so that the locking arm is movable. The movable part is locked by contacting the part.

  According to the present invention configured as described above, since the movable portion is locked by the locking arm, the movable portion is locked at the predetermined position even when the movable portion is not held at the predetermined position. can do.

  In the present invention, preferably, three sets of drive coils and drive magnets are provided, and the first set of these is arranged so that the line of action of the generated drive force generally passes through the optical axis. Are arranged such that the action line of the driving force generated is orthogonal to the action line of the driving force generated by the first set, and the action line of the driving force substantially passes through the optical axis. The action line of the generated driving force is arranged so as to be directed substantially in the tangential direction of the circle centered on the optical axis, and the locking coil generates a magnetic force with the third set of driving magnets. Are arranged to be.

  In the present invention configured as described above, the movable portion is translated by the first and second sets of the driving coil and the driving magnet, which are arranged so that the action line of the driving force substantially passes through the optical axis. Then, image blur prevention control is executed. In addition, during the image blur prevention control, the third set of driving coils and driving magnets in which the line of action of the driving force is directed substantially in the tangential direction of the circle with the optical axis as the center, the rotation generated in the movable portion. Acts to suppress movement. According to the present invention thus configured, the locking coil generates a magnetic force with the third set of driving magnets that generate a driving force in a substantially tangential direction of a circle centered on the optical axis. Therefore, the movable portion locking mechanism can be easily rotated and the generated driving force can be used efficiently.

In addition, the present invention is a lens unit including an anti-vibration actuator, and includes a lens barrel, an imaging lens disposed inside the lens barrel, and the anti-vibration actuator of the present invention. It is a feature.
Furthermore, the present invention is a camera provided with an anti-vibration actuator, and includes a camera body and the lens unit of the present invention.

  According to the vibration-proof actuator of the present invention, and the lens unit and camera including the same, the movable part can be locked while preventing an increase in size.

It is sectional drawing of the camera by embodiment of this invention. It is side surface sectional drawing of the vibration proof actuator with which the camera by embodiment of this invention is equipped. It is a front view which shows the state which removed the movable part of the vibration proof actuator and looked at the stationary plate from the to-be-photographed object side. It is a rear view which shows the state which removed the stationary plate of the vibration proof actuator and looked at the movable part from the photographer side of the camera. It is the front view which looked at the vibration isolator from the to-be-photographed object side of the camera. It is sectional drawing which follows the VI-VI line of FIG. It is sectional drawing which follows the VII-VII line of FIG. It is a disassembled perspective view which shows the movable part latching mechanism in the modification of embodiment of this invention. It is sectional drawing which shows the positional relationship of the 3rd drive coil in the modification of embodiment of this invention, the 3rd drive magnet, and the latching coil.

Next, embodiments 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. 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 lens unit 2 and a camera body 4. The lens unit 2 includes a lens barrel 6, a plurality of imaging lenses 8 disposed in the lens barrel, an image stabilization actuator 10 that moves the image blur prevention lens 16 within a predetermined plane, and a lens. And a gyro 34 which is a vibration detecting means for detecting the vibration of the lens barrel 6.

  In the camera 1 according to the embodiment of the present invention, the vibration is detected by the gyro 34, and the image stabilization actuator 10 is operated based on the detected vibration to move the image stabilization lens 16. The image focused on the surface 4a is stabilized. In the present embodiment, a piezoelectric vibration gyro is used as the gyro 34. 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 lens unit 2 is attached to the camera body 4 and configured to form incident light on the image sensor surface 4a.
The generally cylindrical lens barrel 6 holds a plurality of imaging lenses 8 therein, and allows focus adjustment by moving some imaging lenses 8.

  Next, the vibration-proof actuator 10 will be described with reference to FIGS. FIG. 2 is a side sectional view of the vibration-proof actuator 10. FIG. 3 is a front view showing a state in which the movable part of the vibration isolation actuator 10 is removed, and FIG. 4 is a front view of the movable part of the vibration isolation actuator 10. 2 is a cross-sectional view showing a state in which the vibration-proof actuator 10 is broken along the line II-II in FIG.

  As shown in FIGS. 2 to 4, the anti-vibration actuator 10 is supported by a fixed plate 12 which is a fixed portion fixed in the lens barrel 6, and can be translated and rotated with respect to the fixed plate 12. A movable frame 14 that is a movable portion, and three steel balls 18 that are movable portion support means for supporting the movable frame 14. Further, the vibration-proof actuator 10 includes a first drive magnet 22a, a second drive magnet 22b, and a third drive magnet 22c attached to the fixed plate 12, and a first drive coil attached to the moving frame 14. 20a, the second drive coil 20b, the third drive coil 20c, and the first magnetic elements that are first, second, and third position detection elements disposed inside the drive coils 20a, 20b, and 20c, respectively. A sensor 24a, a second magnetic sensor 24b, and a third magnetic sensor 24c. The first drive magnet 22a, the second drive magnet 22b, and the third drive magnet 22c face the first drive coil 20a, the second drive coil 20b, and the third drive coil 20c, respectively. Are arranged at corresponding positions.

  The first driving coil 20a and the first driving magnet 22a, which are the first set, the second driving coil 20b and the second driving magnet 22b, which is the second set, and the third set, the third set. The drive coil 20c and the third drive magnet 22c constitute first, second, and third drive means for driving the moving frame 14 with respect to the fixed plate 12, respectively.

  Further, as shown in FIG. 1, the vibration isolation actuator 10 detects vibration detected by the gyro 34 and positional information of the moving frame 14 detected by the first, second, and third magnetic sensors 24 a, 24 b, and 24 c. Based on the controller 36, the controller 36 is a control unit that controls the current flowing through the first, second, and third drive coils 20a, 20b, and 20c.

  The anti-vibration actuator 10 translates the moving frame 14 relative to the fixed plate 12 fixed to the lens barrel 6 in a plane parallel to the imaging element surface 4 a, and thereby image blur attached to the moving frame 14. Even if the prevention lens 16 is moved and the lens barrel 6 vibrates, it is driven so that the image formed on the imaging element surface 4a is not disturbed.

  The fixed plate 12 has a generally donut plate shape, and the first, second, and third drive magnets 22a, 22b, and 22c are disposed thereon. As shown in FIG. 3, the centers of these three drive magnets are arranged on the circumference of a circle centered on the optical axis A of the lens unit 2. In the present embodiment, the first drive magnet 22a is disposed vertically above the optical axis A, the second drive magnet 22b is disposed in the horizontal direction with respect to the optical axis, and the third drive magnet 22c is The first driving magnet 22a and the second driving magnet 22b are disposed at positions separated by a central angle of 135 °. Accordingly, the central angle between the first driving magnet 22a and the second driving magnet 22b is 90 °, the central angle between the second driving magnet 22b and the third driving magnet 22c is 135 °, and the driving magnets 22c and 22a. Are separated by a central angle of 135 °.

  The first and second drive magnets 22a and 22b have a generally rectangular shape, and are arranged so that the center lines crossing the long sides thereof coincide with the Y axis and the X axis, respectively. The first and second drive magnets 22a and 22b are magnetized so that the center line crossing the short side becomes the magnetization boundary line C. The third driving magnet 22c has a substantially rectangular shape that is longer than the first and second driving magnets, and is arranged so that the center line that crosses the long side thereof coincides with the radial direction of the circle. Further, the third driving magnet 22c is magnetized so that the center line crossing the long side becomes the magnetization boundary line C. That is, the first and second drive magnets 22a and 22b have the magnetization boundary line C oriented in the tangential direction of the circle centered on the optical axis A, and the third drive magnet 22c has the circular magnetization boundary line C aligned with the circle. Are arranged so as to face in the radial direction.

  As shown in FIG. 2, the moving frame 14 has a substantially donut plate-like flat plate portion 14 a and a cylindrical portion 14 b formed at the center thereof, and is arranged so as to overlap the fixed plate 12 in parallel with the fixed plate 12. Has been. An image blur prevention lens 16 is attached inside the cylindrical portion 14b. As shown in FIG. 4, first, second, and third drive coils 20a, 20b, and 20c are attached on the circumference of a circle centered on the optical axis of the flat plate portion 14a. These first, second, and third drive coils 20a, 20b, and 20c correspond to the first, second, and third drive magnets 22a, 22b, and 22c on the fixed plate 12 so as to face each other. Is arranged.

  The first, second, and third drive coils 20a, 20b, and 20c 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 Y axis and the X axis, respectively. That is, the first and second drive coils 20a and 20b are arranged so that their long sides are directed in a tangential direction of a circle having the optical axis A as the center. The third drive coil 20c is generally rectangular in shape smaller than the first and second drive coils, and the center line that crosses the short side of the third drive coil 20c faces the radial direction of the circle centered on the optical axis A. Are arranged as follows.

As shown in FIGS. 2 and 3, the three steel balls 18 are sandwiched between the fixed frame 12 and the moving frame 14, and each have a central angle of 120 ° on the circumference of a circle centered on the optical axis A. They are arranged at intervals. Each steel ball 18 is disposed in a recess 30 formed at a position corresponding to each steel ball 18 in the fixed frame 12, and is prevented from falling off. As will be described later, since the moving frame 14 is attracted to the fixed plate 12 by the attracting magnet, each steel ball 18 is sandwiched between the fixed plate 12 and the moving frame 14. As a result, the moving frame 14 is supported on a plane parallel to the fixed plate 12, and each steel ball 18 is rolled while being held, so that translational movement and rotational movement of the moving frame 14 with respect to the fixed plate 12 are allowed. Is done.
Further, in the present embodiment, a steel sphere is used as the steel ball 18, but the moving frame 14 can be supported with respect to the fixed plate 12 by a resin sphere, for example.

Further, the vibration isolation actuator 10 is attached to the moving frame 14 and the three attracting magnets 26 attached to the fixed plate 12 in order to attract the moving frame 14 to the fixed plate 12 by the magnetic force of each driving magnet. And three suction yokes 28.
As shown in FIG. 3, the attracting magnet 26 is a rectangular plate-shaped magnet attached on the fixed plate 12, and is disposed on the circumference of a circle centered on the optical axis.
As shown in FIG. 4, the attracting yoke 28 is a rectangular plate-shaped yoke attached on the moving frame 14, and is disposed so as to face the attracting magnets 26 attached to the fixed plate 12. Yes. The moving frame 14 is attracted to the fixed plate 12 by the magnetic force exerted by each attracting magnet 26 on the attracting yoke 28.

Next, the driving force generated by each driving magnet and driving coil will be described.
As shown in FIG. 3, the magnetization boundary line C of the first driving magnet 22a is positioned so as to pass through the midpoint of each short side of the rectangular first driving magnet 22a, and as shown in FIG. The polarity of the first driving magnet 22a also changes in the thickness direction. In the present embodiment, the lower left corner in FIG. 2 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. 3). 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 first and second drive coils 20a and 20b arranged to face each other. The magnetism of the first and second drive magnets 22a and 22b mainly acts 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 vertical driving force along the Y axis is generated between the first driving magnet 22a and a current flows through the second driving coil 20b. A horizontal driving force along the X axis is generated between the second driving magnet 22b.

  That is, the line of action of the driving force by the first driving means constituted by the first driving coil 20a and the first driving magnet 22a generally passes through the optical axis A of the image blur prevention lens 16, and the second driving coil. The action line of the driving force by the second driving means constituted by 20b and the second driving magnet 22b is substantially orthogonal to the action line of the driving force by the first driving means, and the optical axis A of the image blur prevention lens 16 It passes almost through.

  On the other hand, as shown in FIG. 3, the third driving magnet 22c is arranged so that the magnetization boundary line C is directed in the radial direction of a circle centered on the optical axis A, and is a rectangular third driving coil. Magnetism is exerted on the long side portion 20c of 20c that is directed in the radial direction. As a result, when a current flows through the third driving coil 20c, a driving force in a substantially tangential direction of a circle centered on the optical axis A is generated between the third driving magnet 22c and the third driving magnet 22c. Further, the third driving coil 20c and the third driving magnet 22c constituting the third driving means are configured to be smaller than the first and second driving coils and the first and second driving magnets. The driving force generated by the third driving unit when the same current flows through the driving coil is smaller than the driving force generated by the first and second driving units.

  In the present embodiment, the center of gravity of the movable part (the moving frame 14, the image blur prevention lens 16, and each drive magnet) of the image stabilization actuator 10 is located substantially on the optical axis A. Due to the driving force of the first driving means directed in the radial direction of the center circle, the moving frame 14 is translated almost exactly in the vertical direction. Similarly, the moving frame 14 is translated almost accurately in the horizontal direction by the driving force of the second driving means. Since the third driving means is provided so as to suppress a slight rotational movement caused by the translational movement of the moving frame 14, the driving force that needs to be generated by the third driving means is the first and second driving forces. It is smaller than the driving means.

  As shown in FIGS. 2 and 4, a first magnetic sensor 24a, a second magnetic sensor 24b, and a third magnetic sensor 24c are arranged inside each driving coil, respectively. The first, second, and third magnetic sensors 24a, 24b, and 24c are positions of the moving frame 14 with respect to the fixed plate 12 in a direction parallel to the action line of the driving force generated by the first, second, and third driving means. Is configured to measure. Each magnetic sensor is arranged such that when the moving frame 14 is at the control center position, the sensitivity center point D is positioned on the magnetization boundary line C of each drive magnet. 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 D 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 D is When it deviates from the magnetization boundary line C of the driving magnet, the output signal of the magnetic sensor changes. During the normal operation of the vibration isolating actuator 10, the amount of movement of the driving magnet is very small, so that a signal substantially proportional to the moving distance in the direction perpendicular to the magnetization boundary line C of the driving magnet is output from the magnetic sensor. Is done.

  For this reason, the first magnetic sensor 24a outputs a signal substantially proportional to the translational movement amount of the moving frame 14 in the Y-axis direction, and the second magnetic sensor 24b is substantially proportional to the translational movement amount of the moving frame 14 in the X-axis direction. Output a signal. Further, the third magnetic sensor 24c outputs a signal containing a lot of rotational movement components of the movement of the moving frame 14. Based on the signals detected by the first, second, and third magnetic sensors 24a, 24b, and 24c, the position where the moving frame 14 is translated and rotated with respect to the fixed frame 12 can be specified.

Next, control of the vibration isolation actuator 10 by the controller 36 will be described.
First, the vibration of the lens unit 2 is detected momentarily by the gyro 34 (FIG. 1) and input to the controller 36. In the present embodiment, the gyro 34 is configured to detect the angular velocity of the pitching motion and yawing motion of the lens unit 2, respectively.

  In the controller 36, a lens position command signal for commanding in time series the position where the image blur prevention lens 16 should be moved is calculated based on the angular velocity input from the gyro 34 every moment. By moving the image blur prevention lens 16 momentarily according to this lens position command signal, even when the lens unit 2 vibrates during the exposure of photography, it is focused on the image sensor surface 4a in the camera body 4. The image is stabilized without being disturbed.

  The controller 36 supplies currents to the first, second, and third drive coils 20a, 20b, and 20c so that the image blur prevention lens 16 is moved to the position indicated by the generated lens position command signal. To control.

  On the other hand, the amount of vertical movement of the first drive coil 20a relative to the first drive magnet 22a is measured by the first magnetic sensor 24a. The amount of horizontal movement of the second drive coil 20b relative to the second drive magnet 22b is measured by the second magnetic sensor 24b. The amount of movement of the third drive coil 20c relative to the third drive magnet 22c is measured by the third magnetic sensor 24c. Here, the third magnetic sensor 24c measures the distance between the sensitivity center point D of the third magnetic sensor 24c and the magnetization boundary line C of the third driving magnet 22c.

  Based on the amount of movement measured by each magnetic sensor, the controller 36 controls the current that flows through each driving coil so that the moving frame 14 is translated to the position specified by the lens position command signal. When the moving frame 14 is accurately translated to the position specified by the lens position command signal, no current flows through each driving coil, and the driving force becomes zero.

  Even if the first and second drive coils 20a and 20b are respectively moved to the positions commanded by the lens position command signal, the third drive is performed when the moving frame 14 is rotationally moved together with the translational movement. A current flows through the coil 20c. Due to the current flowing through the third driving coil 20c, a driving force for rotating the moving frame 14 acts between the third driving magnet 22c. Thereby, the rotational movement of the moving frame 14 is canceled and the moving frame 14 is accurately translated. In the vibration-proof actuator 10 according to the present embodiment, the first, second, and second moving frames 14 are supported by the three steel balls 18 so as to be able to translate and rotate with respect to the fixed plate 12. When the third driving means cooperates to generate a driving force, the rotational movement of the moving frame 14 is suppressed, and the moving frame 14 is accurately translated.

Next, a mechanism for locking the movable portion will be described with reference to FIGS.
FIG. 5 is a front view of the vibration-proof actuator 10 as viewed from the subject side of the camera 1. 6 is a sectional view taken along line VI-VI in FIG. 5, and FIG. 7 is a sectional view taken along line VII-VII in FIG.
As shown in FIGS. 5 and 6, the vibration-proof actuator 10 further includes an annular lock member 38, a locking coil 40 attached to the annular lock member 38, and the locking coil 40. And a closed magnetizing yoke 42.

  As shown in FIGS. 5 and 6, the annular lock member 38 is a circular plate member, and a substantially circular opening is provided at the center thereof. The cylindrical portion 14b of the moving frame 14 is received in the opening of the annular lock member 38, and the cylindrical portion 14b extends so as to protrude from the annular lock member 38. The annular lock member 38 is supported inside the lens barrel 6 so as to be rotatable about the optical axis A, and is also rotatable relative to the moving frame 14. In the present embodiment, the annular lock member 38 functions as a movable portion locking mechanism.

  On the other hand, as shown in FIG. 5, three protrusions 14c extending in the direction of the optical axis A are provided on the side surface of the cylindrical portion 14b. These three protrusions 14c are provided at intervals of a central angle of 120 ° with the optical axis A as the center. In addition, at the edge of the opening portion of the annular lock member 38, three concave portions 38b are provided at positions corresponding to the respective projections 14c, and during the image blur prevention control of the image stabilization actuator 10, the projections 14c and The annular locking member 38 does not come into contact. Further, when the annular lock member 38 is rotated with respect to the moving frame 14 about the optical axis A, each recess 38b is moved to a position indicated by an imaginary line in the drawing. Thereby, each protrusion 14c is contact | abutted with the contact part 38a which is an inner peripheral surface of the opening part of the cyclic | annular locking member 38, respectively, and the movement frame 14 is latched.

  As shown in FIGS. 6 and 7, the locking coil 40 is attached to the surface on the moving frame 14 side of the annular lock member 38 at a position corresponding to the third drive magnet 22 c. That is, the third driving coil 20c attached to the moving frame 14 is disposed so as to face the third driving magnet 22c attached to the fixed plate 12, and is positioned on the back side of the third driving coil 20c. Thus, the locking coil 40 is arranged. Further, as shown in FIG. 5, the locking coil 40 is a coil wound in a rectangular shape with rounded corners, and the center line crossing the long side is directed in the radial direction of a circle centered on the optical axis A. It is attached as follows.

  The long side of the locking coil 40 is configured to be longer than the short side of the third driving coil 20c (FIG. 4). As shown in FIG. 7, the locking coil 40 has both ends of the third driving coil 20c. It extends to the outside. Further, the long side of the third driving magnet 22c is formed to be substantially the same length as the long side of the locking coil 40, and the third driving magnet 22c is also outside the both ends of the third driving coil 20c. It extends to.

  As shown in FIG. 5, the closing magnet yoke 42 is a rectangular plate-shaped magnetic material, and is disposed on the back side of the locking coil 40. By disposing the closing magnet yoke 42, a magnetic circuit indicated by an imaginary line arrow in FIG. 7 is formed between the third driving magnet 22c and the closing magnet yoke 42. In this way, since the winding of the locking coil 40 crosses the magnetic field lines extending from the third driving magnet 22c, a current flows through the locking coil 40, so that the locking coil 40 has a driving force. Works. With this driving force, the annular lock member 38 is rotationally driven with respect to the fixed plate 12. Although the third driving magnet 22c is formed smaller than the other driving magnets, the driving force required for driving the annular lock member 38 is smaller than the driving force required for image blur prevention control. A sufficient driving force for rotating the lock member 38 can be obtained.

  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 provided in the lens unit 2 is operated. The gyro 34 attached to the lens unit 2 detects vibration in a predetermined frequency band every moment and outputs it to the controller 36. Based on the angular velocity signal detected by the gyro 34, vertical and horizontal lens position command signals are generated. By moving the image blur prevention lens 16 momentarily to the position commanded by the lens position command signal, the image focused on the image sensor surface 4a of the camera body 4 is stabilized.

  The position of the moving frame 14 to which the image blur prevention lens 16 is attached is detected by the first, second, and third magnetic sensors 24a, 24b, and 24c. When the detected position of the moving frame 14 reaches the position specified by the lens position command signal, the current flowing through each driving coil is set to 0 and the driving force is also set to 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 flows again to each driving coil. When a current flows through each driving coil, a driving force is generated between the opposing driving magnets, and the moving frame 14 is returned to the position specified by the lens position command 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 4a of the camera body 4 is stabilized. During the image blur prevention control, no current flows through the locking coil 40, and the annular lock member 38 is maintained at the position indicated by the solid line in FIG. For this reason, the moving frame 14 and the annular lock member 38 do not contact each other.

Next, when a start switch (not shown) for the camera shake prevention function of the camera 1 is turned off, the image blur prevention control is finished, and the moving frame 14 is locked by the annular lock member 38.
First, when the image blur prevention control is finished, the controller 36 controls the moving frame 14 to move to the control center position shown in FIG. 5 so that the moving frame 14 is held at that position. The control center position is a position where the optical axis of the image blur prevention lens 16 attached to the moving frame 14 and the optical axis of the lens unit 2 coincide with each other and the moving frame 14 is not rotated. Next, the controller 36 applies current to the locking coil 40 to rotate the annular lock member 38 around the optical axis A, and rotates the annular lock member 38 to the locked position indicated by the imaginary line in FIG. Move. Thereby, the contact part 38a which is the inner peripheral wall of the opening part of the annular lock member 38 and the tip of each projection 14c of the moving frame 14 come into contact with each other, and the moving frame 14 is locked at the control center position. That is, the locking coil 40 drives the movable portion locking mechanism constituted by the annular lock member 38 to the locked state. When the moving frame 14 is mechanically locked by the annular lock member 38, the controller 36 stops energization of each driving coil and the locking coil 40.
Even when the power switch (not shown) of the camera 1 is turned off, the moving frame 14 is locked at the control center position by the same operation.

  According to the vibration-proof actuator 10 of the embodiment of the present invention, the first, second, and third drive coils 20a, 20b, and 20c and the first, second, and third drive magnets 22a, 22b, and 22c The moving frame 14 is driven by the magnetic force acting in between, and image blur prevention control is executed. On the other hand, since the annular lock member 38 constituting the movable portion locking mechanism is driven by the magnetic force acting between the locking coil 40 and the third driving magnet 22c, between the locking coil 40 and the annular locking member 38. There is no need to provide a dedicated magnet for generating a magnetic force, and the entire vibration-proof actuator 10 can be downsized.

  Further, according to the vibration-proof actuator 10 of the present embodiment, the locking coil 40 generates a driving force with the third driving magnet 22c attached to the fixed plate 12, so that the generated driving force is generated. The third driving magnet 22c is not moved by this reaction force, and the annular lock member 38 can be driven reliably.

  Furthermore, according to the vibration-proof actuator 10 of the present embodiment, the moving frame 14 is directly locked by the rotation of the annular lock member 38 that constitutes the movable part locking mechanism, so that the movable part locking mechanism is locked. The coil 40 can be easily driven into a locked state.

  Further, according to the vibration-proof actuator 10 of the present embodiment, since the moving frame 14 is locked by the contact portion 38a of the annular lock member 38 directly contacting the protrusion 14c of the moving frame 14, the simple mechanism Thus, the movable part locking mechanism can be configured.

  Furthermore, according to the vibration-proof actuator 10 of the present embodiment, the first set including the first drive coil 20a and the first drive magnet 22a, the second set including the second drive coil 20b and the second drive magnet 22b. By the two sets, a driving force whose action line substantially passes through the optical axis is generated. With these driving forces, the moving frame 14 is generally translated during image blur prevention control. The rotation generated in the moving frame 14 is suppressed by a driving force in a substantially tangential direction of a circle centered on the optical axis generated by the third set of the third driving coil 20c and the third driving magnet 22c. The moving frame 14 is accurately translated. Since the locking coil 40 is configured to generate a magnetic force with the third driving magnet 22c that generates a driving force in a generally tangential direction of a circle centered on the optical axis, the annular locking member 38 is configured. Can be driven to rotate easily, and the generated driving force can be used efficiently.

  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 present invention is applied to a digital camera, but the present invention can also be applied to a film camera, a video camera, and the like.

  In the above-described embodiment, the annular lock member constituting the movable portion locking mechanism is in direct contact with the moving frame and locks the moving frame. However, the vibration isolation device having various movable portion locking mechanisms is used. The present invention can be applied to an actuator. For example, as a modification, the moving frame can be locked by a locking arm.

FIG. 8 is an exploded perspective view showing the movable portion locking mechanism in the present modification.
As shown in FIG. 8, the movable portion locking mechanism in the present modification includes an annular lock member 138 and four locking arms 139 driven thereby. The annular lock member 138 is a disk-like member having a circular opening at the center, and is supported so as to be rotatable with respect to the lens barrel 6. Similar to the above-described embodiment, the annular lock member 138 is disposed so that the cylindrical portion 14b of the moving frame 14 protrudes through the opening.

A closed magnetic yoke 142 is attached to one surface of the annular lock member 138, and a locking coil 140 is attached to the closed magnetic yoke 142. The closing magnet yoke 142 is arranged so as to form a magnetic circuit with the third driving magnet attached to the fixed portion 12 as in the above-described embodiment. Therefore, a driving force is generated by passing a current through the locking coil 140, and the annular lock member 138 is rotationally driven with respect to the fixed portion 12.
On the other hand, four cam grooves 138a are formed on the surface of the annular locking member 138 on which the magnetic closing yoke 142 is not attached.

Four locking arms 139 are arranged on the surface of the annular lock member 138 on the cam groove 138a side.
Each locking arm 139 is an elongated plate-like member, and a support shaft 139a is provided at one end of the surface, and a cam projection 139b is provided at the opposite end of the other surface. . The support shaft 139a of the locking arm 139 is received in a bearing hole (not shown) fixed in the lens barrel 6, whereby each locking arm 139 is centered on the support shaft 139a. Is rotatably supported. On the other hand, cam protrusions 139b protruding from the opposite surface of each locking arm 139 are received in cam grooves 138a formed in the annular lock member 138, respectively.

  With this configuration, when the annular lock member 138 is rotated about the optical axis, the cam protrusion 139b is moved along the cam groove 138a. Accordingly, each locking arm 139 is rotated about each support shaft 139a. When each locking arm 139 is rotated inward in the radial direction, each locking arm 139 comes into contact with the outer peripheral surface of the cylindrical portion 14b of the moving frame 14, and the moving frame 14 is mechanically moved to the control center position. It is locked to. That is, the locking coil 140 drives the movable portion locking mechanism including the annular lock member 138 and the locking arm 139 to the locked state.

  According to this modification, the four locking arms 139 disposed around the cylindrical portion 14b of the moving frame 14 (around the image blur prevention lens 16) are moved inward in the radial direction. Is pressed and locked. Therefore, even when the moving frame 14 is not held at the control center position, each locking arm 139 moves the moving frame 14 to the control center position and locks the moving frame 14 at the control center position. be able to. In this modification, four locking arms are provided. However, any number of locking arms, three or more, can be provided.

  In the embodiment described above, the drive coil is attached to the movable part and the drive magnet is attached to the fixed part. However, as shown in FIG. 9 as a modification, the drive magnet is attached to the movable part. A coil can also be attached to a fixed part. FIG. 9 is a cross-sectional view showing the positional relationship among the third drive coil, the third drive magnet, and the locking coil in this modification.

  As shown in FIG. 9, in this modification, the third driving coil 220 c is attached to the fixed plate 212, the third driving magnet 222 c is attached to the moving frame 214, and the locking coil is attached to the annular lock member 238. 240 is attached respectively. Further, a closing magnet yoke 242 is attached to the back side of the locking coil 240. In this configuration, when a current is passed through the third driving coil 220c, a driving force for driving the moving frame 214 is generated between the third driving magnet 222c and the third driving magnet 222c. On the other hand, when an electric current is passed through the locking coil 240 disposed on the back side of the third driving magnet 222c, the annular lock member 238 is rotated between the third driving magnet 222c and the locking coil 240. Driving force is generated.

  When the moving frame 214 is locked, the controller applies a current to each driving coil attached to the fixed plate 212 to hold the moving frame 214 to which each driving magnet is attached at the control center position. The controller causes the annular lock member 238 to rotate by a driving force acting between the third driving magnet 222c of the moving frame 214 by passing a current also through the locking coil 240 while maintaining this state. The reaction force acts on the moving frame 214 by rotating the annular lock member 238 relative to the moving frame 214, but the driving coils of the fixed plate 212 and the driving magnets of the moving frame 214 By generating a large control force between them, the moving frame 214 can be held at the control center position against the reaction force. After the annular lock member 238 is moved to the locking position and the moving frame 214 is mechanically locked, the energization of each driving coil and the locking coil 240 is stopped.

DESCRIPTION OF SYMBOLS 1 Camera of embodiment of this invention 2 Lens unit 4 Camera body 4a Image pick-up element surface 6 Lens barrel 8 Imaging lens 10 Anti-vibration actuator 12 Fixing plate (fixing part)
14 Moving frame (movable part)
14a Flat plate part 14b Cylindrical part 14c Protrusion 16 Image blur prevention lens 18 Steel ball (movable part supporting means)
20a First drive coil 20b Second drive coil 20c Third drive coil 22a First drive magnet 22b Second drive magnet 22c Third drive magnet 24a First magnetic sensor (first position detection element)
24b Second magnetic sensor (second position detecting element)
24c 3rd magnetic sensor (3rd position detection element)
26 Suction Magnet 28 Suction Yoke 30 Recess 34 Gyro 36 Controller (Control Unit)
38 annular lock member 38a contact portion 38b recess 40 locking coil 42 closing magnet yoke 138 annular locking member 138a cam groove 139 locking arm 139a support shaft 139b cam projection 140 locking coil 142 closing magnet yoke 212 fixing plate 214 Moving frame 220c Third driving coil 222c Third driving magnet 238 Annular locking member 240 Locking coil 242 Closing yoke

Claims (8)

An anti-vibration actuator for moving the image blur prevention lens,
A fixed part;
A movable part to which the lens for preventing image blur is attached;
Movable part support means for supporting the movable part movably with respect to the fixed part within a plane perpendicular to the optical axis of the image blur prevention lens;
A plurality of driving coils and a plurality of driving magnets disposed so as to face the driving coils, respectively, and the fixed portion is formed by a magnetic force acting between the driving coils and the driving magnets. Driving means for driving the movable part to prevent image blur;
A movable part locking mechanism for mechanically locking the movable part at a predetermined position;
A locking coil attached to the movable part locking mechanism,
The vibration-proof actuator, wherein the locking coil drives the movable portion locking mechanism to a locked state by a magnetic force acting between the driving magnet and the driving magnet.   The vibration-proof actuator according to claim 1, wherein the plurality of driving magnets are attached to the fixed portion, and the plurality of driving coils are attached to the movable portion.   The movable part locking mechanism includes an annular lock member that is rotatably arranged with respect to the movable part and to which the locking coil is attached, and the annular lock member is connected to the driving magnet and the locking magnet. The anti-vibration actuator according to claim 1 or 2, wherein the anti-vibration actuator is rotated by a magnetic force acting between the coils and the movable portion is locked.   The annular lock member includes a contact portion that contacts the movable portion, and the contact portion and the movable portion of the annular lock member are in contact with each other by rotating the annular lock member with respect to the movable portion. The anti-vibration actuator according to claim 3, wherein the movable portion is in contact with the movable portion.   The movable part locking mechanism further includes at least three locking arms, and the locking arm is driven by rotating the annular lock member, and the locking arm is attached to the movable part. The anti-vibration actuator according to claim 3, wherein the movable portion is brought into contact with the movable portion to be locked.   The driving coil and the driving magnet are provided in three sets, and the first set of them is arranged so that the action line of the generated driving force passes through the optical axis, and the second set is The action line of the generated driving force is orthogonal to the action line of the driving force generated by the first set, and the action line of the driving force is arranged so as to substantially pass through the optical axis, and the third set is generated. The drive force acting line is arranged so as to be directed substantially in the tangential direction of the circle centered on the optical axis, and the locking coil generates a magnetic force with the third set of drive magnets. The vibration-proof actuator according to any one of claims 1 to 5, wherein the vibration-proof actuator is arranged so as to perform. A lens unit equipped with an anti-vibration actuator,
A lens barrel;
An imaging lens disposed inside the lens barrel;
The vibration-proof actuator according to any one of claims 1 to 6,
A lens unit comprising: A camera with an anti-vibration actuator,
The camera body,
A lens unit according to claim 7;
A camera characterized by comprising:

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