JP2008287159A - Image-shake preventing actuator, lens unit including the same, and camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an actuator capable of locking movable parts, without making the outside diameter large. <P>SOLUTION: The present invention relates to the actuator (1) for preventing image-shake by moving an imaging lens. The actuator (1) includes a fixed part (12); the movable part (14), including the imaging lens (16); at least three spherical bodies (18) for supporting the movable part; a driving means for driving the movable part; a rolling motion area (50) disposed on the fixed part, while surrounding the spherical body, where the spherical body is made rollable in an arbitry direction; a rolling motion area (54), disposed on the movable part where the spherical body is made rollable in optional directions; a location-restricted area (52), formed continuing from the rolling motion area on the fixed area and extending in the tangent direction of a circle, having an optical axis as its center where a distance from the optical axis to the spherical body is restricted to be a prescribed distance; and a location-restricted area (56) formed extending in the tangential direction of the circle, having the optical axis as its center so as to continue from the rolling motion area on the movable part. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an actuator and a lens unit and a camera including the actuator, and more particularly to an actuator that moves an imaging lens in a plane perpendicular to the optical axis thereof to prevent image blur, and a lens unit and a camera including the actuator. .

  Japanese Unexamined Patent Publication No. 2006-119249 (Patent Document 1) describes an actuator for preventing image blur. In this actuator, a moving frame to which an image blur correction lens is attached is supported by three steel balls, and the image blur correction lens is moved in a plane orthogonal to the optical axis. Further, in this actuator, the moving frame is rotated to the locking position around the optical axis, and the projection formed around the moving frame and the cam-like member provided corresponding thereto are engaged. Thus, the moving frame is locked.

  The actuator described in Japanese Patent Application Laid-Open No. 2006-119249 is advantageous because the moving frame can be locked without providing a special actuator for locking the moving frame.

JP 2006-119249 A

  However, in the actuator described in Japanese Patent Laid-Open No. 2006-119249 described above, a protrusion for locking the moving frame (movable part) and a cam-like member for engaging with the protrusion are arranged on the outer periphery of the moving frame. There is a problem that the outer diameter of the actuator is increased.

  In the above actuator, even when the moving frame (movable part) is locked, the steel ball (spherical body) that locks the moving frame is not locked. There is a problem that the steel balls may fall off when the squeezes act.

  Furthermore, in the above actuator, since the steel ball is not positioned even when the moving frame (movable part) is locked, when returning to the image blur prevention control, the steel ball is surely positioned in a proper position. There is a problem that is difficult.

  Accordingly, an object of the present invention is to provide an actuator capable of locking a movable part without increasing the outer diameter, a lens unit including the actuator, and a camera.

  Another object of the present invention is to provide an actuator that can lock the spherical body when the movable part is locked, a lens unit including the actuator, and a camera.

  Furthermore, an object of the present invention is to provide an actuator that can position a spherical body when the movable part is locked, a lens unit including the actuator, and a camera.

  In order to solve the above-described problems, the present invention is an actuator for moving an imaging lens within a plane orthogonal to the optical axis thereof to prevent image blur, and the fixing unit and the imaging lens are attached to the actuator. A movable part, at least three spherical bodies sandwiched between the movable part and the fixed part and movably supporting the movable part, and drive means for moving the translational part in translation and rotation with respect to the fixed part And a fixed portion rolling area demarcating wall that is provided in the fixing portion so as to surround each spherical body and demarcates a rolling area in which the spherical body can roll in an arbitrary direction, and surrounds each spherical body. The movable part rolling region demarcating wall that demarcates the rolling region in which the spherical body can roll in any direction on the inside, and the optical axis continuously to the rolling region of the fixed part The optical axis is formed so as to extend almost tangentially to the circle At least two fixed portion restricting region defining walls for defining a position restricting region for restricting the distance to the spherical body to a predetermined distance, and a rolling region of the movable part corresponding to each of the fixed portion restricting region defining walls. And a movable part restricting region defining wall for defining a position restricting region extending in a substantially tangential direction of a circle centered on the optical axis so as to be continuous with the optical axis.

  In the present invention configured as described above, the movable portion to which the imaging lens is attached is supported by at least three spherical bodies so as to be movable with respect to the fixed portion. Each spherical body includes a rolling area inside the fixed part rolling area defining wall provided in the fixed part so as to surround the spherical body, and a rolling area inside the movable part rolling area defining wall provided in the movable part. Is sandwiched between. At least two position restricting regions extending in the tangential direction of the circle centered on the optical axis are defined by the fixed portion restricting region defining wall and the movable portion restricting region defining wall so as to be continuous with these rolling regions.

  According to the present invention thus configured, the spherical body is sandwiched between at least two position restraining regions, so that the movement of the movable portion in the radial direction around the optical axis is restrained at at least two points. Therefore, the translational movement of the movable part is locked. Thereby, a movable part can be latched, without enlarging the outer diameter of an actuator.

  In the present invention, preferably, further, a fixed portion adjustment region defining wall for defining a linear fixed portion adjustment region continuously extending from the rolling region of the fixed portion, and a line continuously extending from the rolling region of the movable portion. A movable portion adjustment region defining wall for defining a movable portion adjustment region, and at least one of the fixed portion adjustment region and the movable portion adjustment region intersects a circumference of a circle centering on the optical axis. Is defined.

  According to the present invention configured as described above, the fixed portion adjustment region and / or the movable portion adjustment region intersects the circumference of a circle centered on the optical axis, and thus the fixed portion adjustment region and the movable portion adjustment region. The distance between the spherical body sandwiched between and the optical axis can be varied. Accordingly, it is possible to allow an error in the position and size of the position constraint region while reliably positioning the spherical body sandwiched between the fixed portion adjustment region and the movable portion adjustment region.

In the present invention, preferably, three sets of the fixed portion rolling region defining wall and the movable portion rolling region defining wall are formed, two of these are formed with the position constraint region, and the other set is fixed. A part adjustment area and a movable part adjustment area are formed.
According to the present invention configured as described above, the movable portion can be supported without play at three points.

  In the present invention, it is preferable that the surface in contact with the spherical body, which is surrounded by the fixed portion restraining region defining wall or the movable portion restraining region defining wall, has a curved surface having substantially the same radius of curvature as the surface of the spherical body.

  According to the present invention configured as described above, since the contact area in contact with the spherical body can be increased in a state where the spherical body is located in each position restraint region, the contact pressure can be reduced.

  In the present invention, preferably, the spherical body further includes a rotation locking means for locking the rotation of the movable portion relative to the fixed portion in a state where the spherical body is positioned in each position restraining region of the fixed portion and the movable portion.

  According to the present invention configured as described above, the rotation locking means locks the rotation of the movable portion with respect to the fixed portion, thereby maintaining the movable portion in a state in which the translational movement is locked by each position constraint region. can do.

The lens unit of the present invention includes a lens barrel, a plurality of imaging lenses housed in the lens barrel, and an actuator of the present invention in which a part of these imaging lenses is attached to a movable part. It is characterized by having.
Furthermore, the camera of the present invention has a camera body and the lens unit of the present invention.

According to the actuator of the present invention and the lens unit and camera including the actuator, the movable part can be locked without increasing the outer diameter.
Further, according to the actuator of the present invention, the lens unit including the same, and the camera, the spherical body can be locked when the movable part is locked.
Furthermore, according to the actuator of the present invention and the lens unit and camera including the actuator, the spherical body can be positioned when the movable part is locked.

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, and an actuator that moves an image blur correction lens 16 of the imaging lenses within a predetermined plane. 10 and gyros 34a and 34b (only 34a is shown in FIG. 1) as vibration detecting means for detecting vibration of the lens barrel 6.

The lens unit 2 is attached to the camera body 4 and configured to form incident light on the film surface F.
The generally cylindrical lens barrel 6 holds a plurality of imaging lenses 8 therein, and allows focus adjustment by moving some imaging lenses 8.

  The camera 1 according to the embodiment of the present invention detects vibrations by the gyros 34 a and 34 b, operates the actuator 10 based on the detected vibrations to move the image blur correction lens 16, and moves the film surface in the camera body 4. The image focused on 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 correction lens 16 is constituted by a single lens, but the lens for stabilizing the image may be a plurality of lens groups.

  Next, the configuration of the actuator 10 will be described with reference to FIGS. FIG. 2 is a front view of the actuator 10 in which the moving frame is at the operation center position of the image blur prevention control. FIG. 3 is a front view of the actuator 10 with the moving frame in the locking position. 4 is a side sectional view taken along line IV-IV in FIG. 3, and FIG. 5A is a side sectional view taken along line V-V in FIG. FIG. 5B is a perspective view showing a magnetized state of the driving magnet.

  As shown in FIGS. 2 to 5, the actuator 10 includes a fixed frame 12 that is a fixed portion fixed in the lens barrel 6 and a movable portion that is supported movably with respect to the fixed frame 12. It has a frame 14 and three steel balls 18 that are spherical bodies that support the moving frame 14.

  Further, the actuator 10 includes three driving coils 20a, 20b, and 20c attached to the fixed frame 12, and three drives attached to the moving frame 14 at positions corresponding to the driving coils 20a, 20b, and 20c, respectively. Magnets 22a, 22b, and 22c.

  Further, as shown in FIG. 5A, the actuator 10 is provided with an attracting member attached to the fixed frame 12 so that the moving frame 14 is attracted to the fixed frame 12 by the magnetic force of each driving magnet 22a, 22b, 22c. A yoke 26 and a back yoke 28 attached to the back side of the drive magnet so as to effectively direct the magnetic force of the drive magnet toward the fixed frame 12 are included. The driving coils 20a, 20b, and 20c and the three driving magnets 22a, 22b, and 22c attached to the corresponding positions constitute a linear motor, and the movable frame 14 is translated with respect to the fixed frame 12. And functions as a driving means for rotational movement.

  Further, as shown in FIG. 5 (a), Hall elements 24a, 24b, and 24c, which are magnetic sensors, are arranged inside the windings of the drive coils 20a, 20b, and 20c (FIG. 5). Only 24a is shown). Each Hall element 24a, 24b, 24c detects the magnetism of each driving magnet 22a, 22b, 22c arranged so as to face each other, and detects the position of the moving frame 14 with respect to the fixed frame 12. It is configured. These Hall elements 24a, 24b, 24c and the drive magnets 22a, 22b, 22c constitute position detecting means.

  Further, as shown in FIG. 1, the actuator 10 includes each drive coil 20a based on the vibration detected by the gyros 34a and 34b and the positional information of the moving frame 14 detected by the Hall elements 24a, 24b and 24c. , 20b, 20c has a controller 36 which is a control means for controlling the current to flow. Further, the controller 36 outputs a locking position moving means 37 for moving the moving frame 14 to the locking position, which is the target position, and a signal for urging the moving frame 14 toward the locking position. Stop direction urging means 47 is incorporated.

  The actuator 10 moves the moving frame 14 with respect to the fixed frame 12 fixed to the lens barrel 6 in a plane parallel to the film surface F, and thereby the image blur correction lens attached to the moving frame 14. 16 is moved so that the image formed on the film surface F is not disturbed even if the lens barrel 6 vibrates.

  As shown in FIG. 2, the fixed frame 12 has a generally donut plate shape with an edge on the outer periphery. The fixed frame 12 is formed with fixed frame receiving portions 13a, 13b, and 13c that are recesses for receiving the steel balls 18. Details of these fixed frame receiving portions will be described later. Furthermore, a locking hook 17 that is a rotation locking means for locking the moving frame 14 is rotatably attached to the fixed frame 12. The locking hook 17 is connected to a solenoid (not shown) and is rotated to lock the moving frame 14.

  As shown in FIG. 2, the moving frame 14 has a generally donut plate shape, and is arranged in the fixed frame 12 so as to be surrounded by the edge of the fixed frame 12. An image blur correction lens 16 is attached to the central opening of the moving frame 14. Further, the moving frame 14 is formed with moving frame receiving portions 15a, 15b, and 15c, which are recesses for receiving the respective steel balls 18. Details of the moving frame receiving unit will be described later. Further, a locking projection 17a that is engaged with the locking hook 17 at the time of locking is formed at a position of the moving frame 14 corresponding to the locking hook 17.

  As shown in FIG. 4, the steel ball 18 is provided between the fixed frame receiving portions 13 a, 13 b, 13 c formed on the fixed frame 12 and the moving frame receiving portions 15 a, 15 b, 15 c formed on the moving frame 14. Each is arranged. Further, as shown in FIGS. 2 and 3, three steel balls 18 are arranged at intervals of a central angle of 120 ° so that each steel ball 18 is positioned between the drive coils. Is arranged. Each steel ball 18 is disposed in a receiving portion formed between the fixed frame 12 and the moving frame 14, and the moving frame 14 is attracted to the fixed frame 12 by the driving magnet 22, so that each steel ball 18 is fixed. It is sandwiched between the frame 12 and the moving frame 14. As a result, the moving frame 14 is supported on a plane parallel to the fixed frame 12, and the rolling motion of the moving frame 14 with respect to the fixed frame 12 in any direction is allowed by rolling while the steel balls 18 are sandwiched. Is done.

  In this embodiment, a steel sphere is used as the steel ball 18, but the steel ball 18 is not necessarily a sphere. That is, if the portion that contacts the fixed frame 12 and the moving frame 14 during the operation of the actuator 10 has a substantially spherical shape, the steel ball 18 can be used. In addition, in this specification, such a form is called a spherical body.

  The three drive coils 20a, 20b, and 20c are disposed on the fixed frame 12, respectively. The driving coils 20 a, 20 b, and 20 c are arranged at their centers on the circumference centered on the optical axis of the lens unit 2. In the present embodiment, the drive coil 20a is disposed vertically above the optical axis, and the drive coils 20b and 20c are disposed with a central angle of 120 ° from the drive coil 20a. That is, the driving coils 20a, 20b, and 20c are arranged at equal intervals on a circumference centered on the optical axis. The driving coils 20a, 20b, and 20c are arranged such that their windings are wound in a rectangular shape with rounded corners, and the center line of the rectangle coincides with the radial direction of the circumference.

  The drive magnets 22a, 22b, and 22c each have a rectangular shape and are embedded in the moving frame 14. The driving magnets 22a, 22b, and 22c are positioned at positions corresponding to the driving coils 20a, 20b, and 20c on the circumference of the moving frame 14. In the present specification, the position corresponding to the driving coil means a position where the influence of the magnetic field formed by the driving coil is substantially reached.

  The three suction yokes 26 are respectively attached to the back side of each driving coil of the fixed frame 12, that is, on the opposite side of the moving frame 14. Each attracting yoke 26 is attracted by the magnetic force of each driving magnet 22 a, 22 b, 22 c arranged corresponding thereto, and thereby the moving frame 14 is attracted to the fixed frame 12. In the present embodiment, the fixed frame 12 is made of a non-magnetic material so that the magnetic lines of force of the driving magnet can efficiently reach the attraction yoke 26.

  The back yoke 28 has a substantially rectangular shape, and is disposed on the back side of the three drive magnets. As shown in FIG. 5A, by attaching each back yoke 28 to the back side of each driving magnet, that is, on the opposite side of each driving coil, the magnetic flux of each driving magnet is applied to the fixed frame 12. (Figs. 2 and 3 show a state in which the back yoke 28 is removed).

  Next, the magnetic force exerted by the driving magnet will be described with reference to FIG. The drive magnets 22a, 22b, 22c, the back yoke 28, and the attracting yoke 26, which are each formed in a substantially rectangular shape, are arranged so that their long sides and short sides overlap each other. The driving coils 20a, 20b, and 20c are arranged such that their sides are parallel to the long and short sides of the rectangular back yoke 28, respectively. Further, each drive magnet is oriented such that the magnetization boundary line C, which is the boundary line between the magnetic poles, coincides with the radial direction of the circumference where each drive magnet is disposed.

  Thereby, the drive magnet 22a, the back yoke 28, and the attracting yoke 26 constitute a magnetic circuit, and magnetic lines of force indicated by arrows in FIG. 5A are formed. When a current flows through the corresponding driving coil 20a, the driving magnet 22a receives a driving force in the tangential direction of the circumference where the driving magnets are arranged. For the other driving coils 20b and 20c, corresponding driving magnets 22b and 22c, a back yoke 28, and an attracting yoke 26 are arranged in the same positional relationship.

  In this specification, the magnetization boundary line C refers to the boundary line of the magnetized magnetic poles when both ends of the drive magnet are magnetized so as to be S pole and N pole, respectively. Shall. Therefore, in this embodiment, the magnetization boundary line C is located so as to pass through the midpoint of the long side of the rectangular driving magnet. Further, as shown in FIG. 5B, the polarity of the driving magnet 22a also changes in the thickness direction. In FIG. 5B, the lower left corner is the S pole, the lower right corner is the N pole, The upper left is the N pole and the upper right is the S pole.

Next, the position detection of the moving frame 14 will be described with reference to FIGS.
6 and 7 are diagrams illustrating the relationship between the movement of the driving magnet 22a and the signal output from the Hall element 24a. As shown in FIG. 6, when the sensitivity center point S of the Hall element 24a is located on the magnetization boundary line C of the driving magnet 22a, the output signal from the Hall element 24a is zero. When the driving magnet 22a is moved together with the moving frame 14, and the sensitivity center point of the Hall element 24a deviates from the magnetization boundary line of the driving magnet 22a, the output signal of the Hall element 24a changes. As shown in FIG. 6, when the driving magnet 22a moves in a direction orthogonal to the magnetization boundary line C, that is, in the X-axis direction, the Hall element 24a generates a sinusoidal signal. Therefore, when the amount of movement is small, the Hall element 24a outputs a signal that is substantially proportional to the distance of movement of the driving magnet 22a. In the present embodiment, when the moving distance of the driving magnet 22a is within about 3% of the length of the long side of the driving magnet 22a, the signal output from the Hall element 24a is the sensitivity center of the Hall element 24a. This is approximately proportional to the distance between the point S and the magnetization boundary line C of the driving magnet 22a. In the present embodiment, the actuator 10 operates within a range in which the output of each Hall element is substantially proportional to the distance in the normal operation region.

  As shown in FIGS. 7A to 7C, when the magnetization boundary line C of the driving magnet 22a is positioned on the sensitivity center point S of the Hall element 24a, the driving is performed as shown in FIG. 7B. When the magnet 22a for rotation is rotated, the output signal from the Hall element 24a is zero even when the driving magnet 22a is moved in the direction of the magnetization boundary line C as shown in FIG. Further, as shown in FIGS. 7D to 7F, when the magnetization boundary line C of the driving magnet 22a deviates from the sensitivity center point S of the Hall element 24a, the sensitivity center point S and the magnetization boundary are separated. A signal proportional to the distance r of the line C is output from the Hall element 24a. Therefore, if the distance r from the sensitivity center point S to the magnetization boundary line C is the same, when the driving magnet 22a moves in a direction perpendicular to the magnetization boundary line C as shown in FIG. When the drive magnet 22a is translated and rotated as shown in FIG. 7 (e) and when it is translated in any direction as shown in FIG. 7 (f), a signal having the same magnitude is output from the Hall element 24a. Is done.

  Although the Hall element 24a has been described here, the other Hall elements 24b and 24c also output similar signals based on the positional relationship with the corresponding driving magnets 22b and 22c. For this reason, based on the signals detected by the Hall elements 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, image blur prevention control by the actuator 10 will be described with reference to FIG. FIG. 8 is a block diagram showing signal processing in the controller 36. As shown in FIG. 8, the vibration of the lens unit 2 is detected momentarily by the two gyros 34 a and 34 b and is input to arithmetic circuits 38 a and 38 b that are lens position command signal generation means 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 lens unit 2, 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 to which the image blur correction 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 corrects predetermined optical characteristics to generate the horizontal component Dx of the lens position command signal. Similarly, the arithmetic circuit 38b Is configured to generate the vertical component Dy of the lens position command signal based on the angular velocity of the pitching motion detected by the gyro 34b. Even if the lens unit 2 vibrates during exposure for photography by moving the image blur correction lens 16 momentarily according to the lens position command signal thus obtained, the film surface in the camera body 4 The image focused on F is stabilized without being disturbed.

  The coil position command signal generating means built in the controller 36 is configured to generate a coil position command signal for each driving coil based on the lens position command signal generated by the arithmetic circuits 38a and 38b. The coil position command signal is obtained when each of the drive coils 20a, 20b, 20c and the corresponding drive magnets 22a, 22b, 22c when the image blur correction lens 16 is moved to the position specified by the lens position command signal. It is a signal showing the positional relationship. That is, when each driving magnet is moved to the position commanded by the coil position command signal for each driving coil, the image blur correction lens 16 is moved to the position commanded by the lens position command signal. Is done. In the present embodiment, since the driving coil 20a is provided vertically above the optical axis, the coil position command signal ra for the driving coil 20a is a horizontal component of the lens position command signal output from the arithmetic circuit 38a. It becomes equal to Dx. Accordingly, the arithmetic circuit 40a, which is a coil position command signal generating means for generating a coil position command signal for the driving coil 20a, outputs the output as it is from the arithmetic circuit 38a. On the other hand, the coil position command signals rb and rc for the drive coils 20b and 20c are generated by arithmetic circuits 40b and 40c, which are coil position command signal generation means, based on the horizontal component Dx and the vertical component Dy of the lens position command signal. Generated.

  On the other hand, the movement amount of the driving magnet with respect to each driving coil, measured by the Hall elements 24a, 24b, and 24c, is amplified to a predetermined magnification by the magnetic sensor amplifiers 42a, 42b, and 42c. The drive circuits 44a, 44b, 44c differ in the difference between the coil position command signals ra, rb, rc output from the arithmetic circuits 40a, 40b, 40c and the signals output from the magnetic sensor amplifiers 42a, 42b, 42c. A proportional current is passed through each drive coil 20a, 20b, 20c. Therefore, when there is no difference between the coil position command signal and the output from each magnetic sensor amplifier, that is, when each drive magnet reaches the position commanded by the coil position command signal, no current flows through each drive coil. The driving force acting on the driving magnet becomes zero. The changeover switch 45 and the second changeover switch 46 arranged between the arithmetic circuits 40a, 40b, and 40c and the drive circuits 44a, 44b, and 44c always operate the arithmetic circuit and the drive circuit in the image blur prevention control mode. It is in a position to connect directly.

  Next, the relationship between the lens position command signal and the coil position command signal when the moving frame 14 is translated will be described with reference to FIG. FIG. 9 is a diagram illustrating a positional relationship between the driving coils 20 a, 20 b, 20 c arranged on the fixed frame 12 and the driving magnets 22 a, 22 b, 22 c arranged on the moving frame 14. First, the center points of the three drive coils 20a, 20b, and 20c are arranged on the points Sa, Sb, and Sc on the circumference of the radius R with the point Q as the origin. The Hall elements 24a, 24b, and 24c are also arranged so that their sensitivity center points S are located on the points Sa, Sb, and Sc. Further, when the moving frame 14 is at the operation center position, the center of the image blur correcting lens 16 and the optical axis of the imaging lens 8 coincide, and the magnetization boundary of each driving magnet corresponding to each driving coil. The midpoint of the line C is also located on each of the points Sa, Sb, and Sc, and each magnetization boundary line C is directed in the radial direction of a circle centered on the point Q. The moving frame 14 is translated around the operation center position, and image blur prevention control is executed.

  Next, the horizontal axis with the point Q as the origin is taken as the X axis, the vertical axis is taken as the Y axis, and the center point Q1 of the image stabilizing lens 16 is Dy, X in the Y axis direction, as shown by the solid line in FIG. Consider a case in which -Dx translation is performed in the axial direction. When the moving frame 14 is moved in this way, the magnetization boundary line C of each of the drive magnets 22a, 22b, and 22c is moved to the position indicated by the alternate long and short dash line in FIG. Here, the distance between the magnetization boundary line C of the driving magnet 22a and the point Sa is ra, the distance between the magnetization boundary line C of the driving magnet 22b and the point Sb is rb, and the driving magnet 22c Let rc be the distance between the magnetization boundary line C and the point Sc. The distances ra, rb, and rc correspond to the movement distances detected by the hall elements 24a, 24b, and 24c when the image stabilizing lens 16 is moved in the Y-axis direction by Dy and in the X-axis direction. . These distances ra, rb, and rc are uniquely determined with respect to the movement distances Dx and Dy in the X-axis direction and the Y-axis direction. Therefore, in order to move the image stabilizing lens 16 in the X-axis direction and the Y-axis direction by Dx and Dy, respectively, the distances ra, rb, and rc corresponding thereto may be given as coil position command signals.

図８において説明した各演算回路４０ａ、４０ｂ、４０ｃは、夫々上記数式１に対応する演算を実行して、各コイル位置指令信号を生成している。 Here, if the positive direction of each distance ra, rb, rc is defined as shown by arrows a, b, c in FIG. 9, the relationship between ra, rb, rc and Dx, Dy is as follows (Formula 1) Given in.

Each of the arithmetic circuits 40a, 40b, and 40c described in FIG. 8 performs an operation corresponding to the above Equation 1, and generates each coil position command signal.

によって与えられる。このように、各駆動用磁石が各駆動用コイルに対して同一距離接線方向に移動されることにより、移動枠１４は、像振れ補正用レンズ１６の光軸と撮像用レンズ８の光軸が一致した状態を保持しながら、光軸を中心に回転される。 Next, a coil position command signal when the moving frame 14 is rotated will be described. In order to rotate the moving frame 14, the same value may be given as each coil position command signal. That is, each coil position command signal for rotating the moving frame 14 clockwise by an angle θ [rad] is:

Given by. In this way, each drive magnet is moved in the tangential direction at the same distance with respect to each drive coil, so that the moving frame 14 has an optical axis of the image blur correction lens 16 and an optical axis of the imaging lens 8. It is rotated around the optical axis while maintaining the coincidence state.

  Next, with reference to FIGS. 1 and 8, the operation of the camera 1 according to the embodiment of the present invention will be described. First, an actuator 10 provided in the lens unit 2 is operated by turning on a start switch (not shown) for the camera shake prevention function of the camera 1. The gyros 34a and 34b attached to the lens unit 2 detect vibrations in a predetermined frequency band every moment and output them to the arithmetic circuits 38a and 38b 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 respect to time to calculate a yawing angle, and adds a predetermined optical characteristic correction thereto to generate a horizontal lens position command signal Dx. Similarly, the arithmetic circuit 38b integrates the input angular velocity signal with respect to time to calculate a pitching angle, adds a predetermined optical characteristic correction thereto, and generates a vertical lens position command signal Dy. An image focused on the film surface F of the camera body 4 by moving the image blur correction 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 Dx output by the arithmetic circuit 38a is output as a coil position command signal ra for the driving coil 20a via the arithmetic circuit 40a. Further, the horizontal lens position command signal Dx and the vertical lens position command signal Dy are input to the arithmetic circuit 40b, and a coil position command signal rb for the drive coil 20b is generated based on the middle expression of Equation 1. Is done. Similarly, the lens position command signals Dx and Dy are input to the arithmetic circuit 40c, and the coil position command signal rc for the drive coil 20c is generated based on the lower expression of Expression 1.

  On the other hand, the Hall element 24a corresponding to the driving coil 20a outputs a detection signal to the magnetic sensor amplifier 42a. The detection signal amplified by the magnetic sensor amplifier 42a is subtracted from the coil position command signal ra for the drive coil 20a, and a current proportional to these differences is output to the drive coil 20a via the drive circuit 44a. Similarly, a current proportional to the difference between the detection signal of the hall element 24b and the coil position command signal rb is output to the driving coil 20b via the drive circuit 44b, and the difference between the detection signal of the hall element 24c and the coil position command signal rc. Is output to the drive coil 20c via the drive circuit 44c.

  When a current flows through each driving coil, a magnetic field proportional to the current is generated. Due to this magnetic field, each driving magnet arranged corresponding to each driving coil receives a driving force in a direction approaching the position specified by the coil position command signals ra, rb, rc, and the moving frame 14 is moved. The When the driving magnet reaches the position specified by the coil position command signal by this driving force, the coil position command signal and the detection signal of the Hall element coincide with each other, so the output of the driving circuit becomes zero and the driving force also becomes zero. In addition, when each driving magnet deviates from the position specified by the coil position command signal due to a disturbance or a change in the coil position command signal, a current flows again to each driving coil. The position is returned to the position specified by the position command signal.

  By repeating the above operation every moment, the image blur correction lens 16 attached to the moving frame 14 having each driving magnet is moved so as to follow the lens position command signal. Thereby, the image focused on the film surface F of the camera body 4 is stabilized.

  Next, a mechanism for locking the moving frame 14 of the actuator 10 built in the camera 1 according to the embodiment of the present invention and its operation will be described with reference to FIGS. 10 to 13 are enlarged views showing the fixed frame receiving portion and the moving frame receiving portion formed on the fixed frame 12 and the moving frame 14, respectively. 10A is a front view of the fixed frame receiving portion 13a formed on the fixed frame 12, FIG. 10B is a cross-sectional view taken along the line bb in FIG. 10A, and FIG. It is sectional drawing which follows c line. FIG. 11 is a diagram showing the positional relationship between the fixed frame receiving portion 13a formed on the fixed frame 12 and the moving frame receiving portion 15a formed on the moving frame 14, and (a) the operation center of image shake correction control. The position, (b) the transition state to the locking position, and (c) the locking position are shown. 12A is a front view of the fixed frame receiving portion 13c, FIG. 12B is a sectional view taken along the line bb in FIG. 12A, and FIG. 12C is a sectional view taken along the line cc in FIG. is there. FIG. 13 is a diagram showing a positional relationship between the fixed frame receiving portion 13c and the moving frame receiving portion 15c. (A) Operation center position of image blur correction control, (b) Transition state to the locking position, c) Each locking position is shown.

  As described above, the actuator 10 translates the moving frame 14 around the operation center position shown in FIG. 2 during image blur prevention control, and stabilizes the image. On the other hand, when the image blur prevention control is not executed or when the camera 1 is not used, the moving frame 14 is moved to the locking position shown in FIG. In the present embodiment, the locking position is set to a position where the moving frame 14 is rotated clockwise around the optical axis of the image blur correction lens 16 from the operation center position shown in FIG.

  The fixed frame receiving portions 13a, 13b, 13c formed on the fixed frame 12 and the moving frame receiving portions 15a, 15b, 15c formed on the moving frame 14 are recesses formed on the fixed frame 12 and the moving frame 14, respectively. The steel balls 18 are disposed in the steel balls 18 to prevent the steel balls 18 from falling off, and the moving frame 14 is locked at the locking position.

  Next, the configuration of the fixed frame receiving portions 13a, 13b, and 13c and the moving frame receiving portions 15a, 15b, and 15c will be described. As shown in FIG. 2, the fixed frame receiving portions 13a, 13b, and 13c are arranged on a circumference D of the fixed frame 12 with the optical axis as the center, and are spaced apart from each other by 120 °. Positioned between the coils. The fixed frame receiving portions 13a and 13b disposed on both sides of the driving coil 20a are formed in the same shape, and the fixed frame receiving portion 13c disposed between the driving coils 20b and 20c has a fixed frame shape. It is different from the receiving parts 13a and 13b.

  On the other hand, the moving frame receiving portions 15a, 15b and 15c are formed on the moving frame 14 at positions corresponding to the fixed frame receiving portions 13a, 13b and 13c, respectively. That is, each moving frame receiving portion is disposed on a circumference D centered on the optical axis, and is positioned between the driving magnets at intervals of 120 °. Further, the moving frame receiving portions 15a and 15b arranged on both sides of the driving magnet 22a are formed in the same shape, and the moving frame receiving portion 15c arranged between the driving magnets 22b and 22c has a moving frame shape. It is different from the receiving portions 15a and 15b.

  As shown in FIG. 10A, the fixed frame receiving portion 13 a includes a rolling region 50 that is a substantially circular depression, and a position constraint region 52 that is formed continuously with the rolling region 50. The periphery of the rolling region 50 is defined by a fixed portion rolling region defining wall 50a. Further, as shown in FIG. 10 (c), the rolling region 50 is a relatively wide region having a flat bottom surface, and in this region, the steel ball 18 can roll in an arbitrary direction. it can. On the other hand, the position restricting region 52 is formed continuously from the rolling region 50 and is configured to protrude from the substantially circular rolling region 50 in a substantially radial direction. Further, the position constraint region 52 is a narrow region, and extends in a substantially tangential direction of the circumference D (FIG. 2) with the optical axis as the center. The peripheral edge of the position restricting region 52 is defined by a fixed portion restricting region defining wall 52a. Further, as shown in FIG. 10B, the position constraint region 52 is formed so that the bottom surface has an arc-shaped cross section, and the radius of curvature of the arc is substantially the same as the radius of the steel ball 18. Is formed.

  The center point of the steel ball 18 arranged in the fixed frame receiving portion 13a can move on the region surrounded by the two-dot chain line A1 in FIG. 10A and on the two-dot chain line A1. That is, in the rolling region 50, when the center of the steel ball 18 rolls to the two-dot chain line A1, the surface of the steel ball 18 contacts the fixed portion rolling region defining wall 50a and moves further outward. I can't. On the other hand, in the position restricting region 52, the distance between the fixed portion restricting region defining walls 52a is narrow, so that the steel balls 18 are in contact with the fixing portion restricting region defining walls 52a on both sides simultaneously. Therefore, in the position restraint area 52, the steel ball 18 can move only in the direction of the circumference D in which the position restraint area 52 extends, and the movement of the steel ball 18 in the direction orthogonal to the circumference D is restrained. That is, the area where the center of the steel ball 18 can move in the position restraining area 52 is linear, and this linear area is the circumference D (FIG. 2) where the fixed frame receiving portion 13a is arranged. Almost matches.

  On the other hand, corresponding to the fixed frame receiving portion 13a, the moving frame receiving portion 15a formed on the moving frame 14 is configured to have substantially the same shape as the fixed frame receiving portion 13a, and the rolling region 54 and the position restricting region. 56 (FIG. 11). Further, the rolling region 54 has a peripheral edge defined by a movable portion rolling region defining wall 54a, and a position restricting region 56 has a peripheral edge defined by the movable portion restricting region defining wall 56a. In addition, as shown in FIG. 2, the position constraint area 56 of the moving frame receiving portion 15a also extends in a substantially tangential direction of the circumference D, but extends in the opposite direction to the position constraint area 52 of the fixed frame receiving portion 13a. Yes.

  In addition, although the structure of the fixed frame receiving part 13a and the moving frame receiving part 15a was demonstrated here, as shown in FIG.2 and FIG.3, the fixed frame receiving part 13b and the moving frame receiving part 15b are also comprised completely the same. ing. In the present embodiment, the position constraint area is formed in a straight line so as to extend substantially in the tangential direction of the circumference D. However, when the length of the position constraint area is long, the position constraint area is It can also be formed in an arc shape extending along the circumference D. In the present specification, “extending substantially in the tangential direction of a circle” includes both a form extending substantially linearly in the tangential direction and a form extending substantially arcuately along the circumference.

Next, with reference to FIG. 11, the relative position of the fixed frame receiving part 13a and the moving frame receiving part 15a and the region where the steel ball 18 can roll will be described.
First, as shown in FIG. 11A, the rolling area 50 of the fixed frame receiving portion 13a and the rolling area 54 of the moving frame receiving portion 15a are substantially overlapped at the operation center position of the image blur correction control. It becomes. In this state, the center of the steel ball 18 is defined by a region surrounded by a two-dot chain line A1 defined by the fixed portion rolling region defining wall 50a of the rolling region 50 and a one-dot chain line defined by the rolling region 54. It is possible to move to an overlapping portion of the area surrounded by A2. During the operation of the image blur correction control, the center of the steel ball 18 is moved in the overlapping portion of the two-dot chain line A1 and the one-dot chain line A2 by moving the moving frame 14 relative to the fixed frame 12. . For example, in FIG. 11A, when the moving frame 14 is moved to the lowermost position with respect to the fixed frame 12, the moving frame receiving portion 15a is moved to the position indicated by the dotted line in the drawing. The steel ball 18 is also moved to the position indicated by the dotted line.

  Next, when the moving frame 14 is moved to the locking position, the moving frame 14 is moved clockwise (rightward in FIG. 11) from the operation center position of the image blur correction control shown in FIG. The As a result, as shown in FIG. 11B, the overlapping portion of the two-dot chain line A1 in the fixed frame receiving portion 13a and the one-dot chain line A2 in the moving frame receiving portion 15a is narrowed, and the movable region of the steel ball 18 is reduced. Gradually narrows.

  Next, as shown in FIG. 11C, when the moving frame 14 is moved to the locking position, the overlapping portion of the two-dot chain line A1 and the one-dot chain line A2 becomes a linear region. That is, in this state, the steel ball 18 is positioned in the position constraint region 56 of the moving frame receiver 15a at the same time as being positioned in the position constraint region 52 of the fixed frame receiver 13a. Therefore, the movement of the moving frame receiving portion 15a in the radial direction (vertical direction in FIG. 11) of the circumference D with respect to the fixed frame receiving portion 13a is blocked by the steel ball 18, and the circumferential direction of the moving frame receiving portion 15a (FIG. 11). Only movement in the left-right direction) is allowed.

  Here, as shown in FIG. 3, when the moving frame 14 is moved to the locking position, the fixed frame receiving portion 13b and the moving frame receiving portion 15b are also moved to the same relative positions as in FIG. Is done. Accordingly, the radial movement of the circumference D with respect to the fixed frame receiving portion 13b of the moving frame receiving portion 15b is blocked by the steel ball 18, and only the moving of the moving frame receiving portion 15b in the circumferential direction is allowed. That is, the moving frame 14 is restrained from moving in the radial direction of the circumference D at two points of the moving frame receiving portions 15a and 15b. Thereby, at the locking position, the translational movement of the moving frame 14 is restricted, and only the rotation of the image blur correction lens 16 around the optical axis is allowed. At this locking position, the optical axis of the image blur correction lens 16 attached to the moving frame 14 coincides with the optical axis of the other imaging lens 8.

Next, the configuration of the fixed frame receiving portion 13c will be described with reference to FIG.
As shown in FIG. 12A, the fixed frame receiving portion 13 c includes a rolling region 58 that is a substantially circular depression, and a fixed portion adjustment region 60 that is formed continuously with the rolling region 58. . The periphery of the rolling region 58 is defined by a fixed portion rolling region defining wall 58a. Further, as shown in FIG. 12C, the rolling region 58 is a relatively wide region having a flat bottom surface. In this region, the steel ball 18 can roll in an arbitrary direction. it can. On the other hand, the fixed portion adjustment region 60 is formed as a narrow region extending in a tangential direction of a circle continuously from the generally circular rolling region 58. Further, the fixed portion adjustment region 60 is inclined outwardly with respect to the tangential direction of the circumference D (FIG. 2) with the optical axis as the center, and extends so as to intersect the circumference D. The periphery of the fixed portion adjustment region 60 is defined by a fixed portion adjustment region defining wall 60a. As shown in FIG. 12B, the fixed portion adjustment region 60 is formed so that the bottom surface has an arc-shaped cross section, and the radius of curvature of the arc is substantially the same as the radius of the steel ball 18. Is formed.

  The center point of the steel ball 18 arranged in the fixed frame receiving portion 13c can move on the region surrounded by the two-dot chain line A1 in FIG. 12A and on the two-dot chain line A1. That is, in the rolling region 58, when the center of the steel ball 18 rolls up to the two-dot chain line A1, the surface of the steel ball 18 contacts the fixed portion rolling region defining wall 58a and moves further outward. I can't. On the other hand, in the fixed portion adjustment region 60, the distance between the fixed portion adjustment region defining walls 60a is narrow, so the steel balls 18 are in contact with the fixed portion adjustment region defining walls 60a on both sides simultaneously. Therefore, in the fixed part adjustment region 60, the steel ball 18 can move only in the direction in which the fixed part adjustment region 60 extends, and the movement of the steel ball 18 in the direction orthogonal to this is restricted. That is, a region where the center of the steel ball 18 can move in the fixed portion adjustment region 60 is linear, and this linear region is a circumference D (FIG. 2) where the fixed frame receiving portion 13c is disposed. Intersect.

  On the other hand, corresponding to the fixed frame receiving portion 13c, the moving frame receiving portion 15c formed on the moving frame 14 is configured in substantially the same shape as the fixed frame receiving portion 13c, and the rolling region 62 and the movable portion adjustment are adjusted. A region 64 (FIG. 13) is provided. Further, the peripheral edge of the rolling region 62 is defined by the movable portion rolling region defining wall 62a, and the peripheral portion of the movable portion adjusting region 64 is defined by the movable portion adjusting region defining wall 64a. Further, as shown in FIG. 2, the movable portion adjustment region 64 of the movable frame receiving portion 15c also extends in the direction intersecting the circumference D, but the direction opposite to the fixed portion adjustment region 60 of the fixed frame receiving portion 13c. It extends to.

Next, with reference to FIG. 13, the relative position of the fixed frame receiving part 13c and the moving frame receiving part 15c, and the area | region where the steel ball 18 can roll are demonstrated.
First, as shown in FIG. 13A, the rolling region 58 of the fixed frame receiving portion 13c and the rolling region 62 of the moving frame receiving portion 15c are substantially overlapped at the operation center position of the image blur correction control. It becomes. In this state, the center of the steel ball 18 is defined by a region surrounded by a two-dot chain line A1 defined by the fixed portion rolling region defining wall 58a of the rolling region 58 and a one-dot chain line defined by the rolling region 62. It is possible to move to an overlapping portion of the area surrounded by A2. During the operation of the image blur correction control, the center of the steel ball 18 is moved in the overlapping portion of the two-dot chain line A1 and the one-dot chain line A2 by moving the moving frame 14 relative to the fixed frame 12. . For example, in FIG. 13A, when the moving frame 14 is moved upwards with respect to the fixed frame 12, the moving frame receiving portion 15c is moved to the position indicated by the dotted line in the drawing, The steel ball 18 is also moved to the position indicated by the dotted line.

  Next, when the moving frame 14 is moved to the locking position, the moving frame 14 is moved clockwise (leftward in FIG. 13) from the operation center position of the image blur correction control shown in FIG. The As a result, as shown in FIG. 13B, the overlapping portion of the two-dot chain line A1 in the fixed frame receiving portion 13c and the one-dot chain line A2 in the moving frame receiving portion 15c becomes narrow, and the movable region of the steel ball 18 is reduced. Gradually narrows.

  Next, as shown in FIG. 13C, when the moving frame 14 is moved to the locking position, the overlapping portion of the two-dot chain line A1 and the one-dot chain line A2 becomes an intersection of them. In other words, in this state, the steel ball 18 is positioned in the fixed frame receiving portion 13c fixed portion adjusting region 60 and at the same time in the moving portion adjusting region 64 of the moving frame receiving portion 15c. For this reason, the center position of the steel ball 18 is limited only to the intersection of the two-dot chain line A1 in the fixed part adjustment area 60 and the one-dot chain line A2 in the movement part adjustment area 64. The position of the intersection of the two-dot chain line A1 and the one-dot chain line A2 varies depending on the rotational position of the moving frame 14 relative to the fixed frame 12.

  As described above, at the locking position, the moving frame 14 is moved by the action of the fixed frame receiving portions 13a and 13b and the moving frame receiving portions 15a and 15b, and the optical axis of the image blur correcting lens 16 and other imaging lenses. The eight optical axes are constrained to coincide. That is, the moving frame 14 is allowed to rotate only around the optical axis by the fixed frame receiving portions 13a and 13b and the moving frame receiving portions 15a and 15b at the locking position. The portion 13c and the moving frame receiving portion 15c allow this rotation by changing the position of the intersection of the two-dot chain line A1 and the one-dot chain line A2.

  Further, since the two-dot chain line A1 in the fixed portion adjustment region 60 and the one-dot chain line A2 in the moving portion adjustment region 64 are directed to intersect, there is an error in the positions and shapes of the fixed frame receiving portion and the moving frame receiving portion. Even in the case where the dot is included, there is always an intersection of the two-dot chain line A1 and the one-dot chain line A2. For this reason, there is no overlapping point between the fixed portion adjustment region 60 and the moving portion adjustment region 64 at the locking position, and the steel ball 18 is simultaneously positioned in the fixed portion adjustment region 60 and the moving portion adjustment region 64. Will not be lost.

  On the other hand, in the present embodiment, if the fixed frame receiving portion 13c and the moving frame receiving portion 15c are configured in the same shape as the fixed frame receiving portion 13a and the moving frame receiving portion 15a, and include a position constraint region. At the locking position, the distance from the optical axis to each steel ball 18 is restricted at three points. For this reason, in the case where an error is included in the positions and shapes of the fixed frame receiving portion and the moving frame receiving portion, or when the dimensions are deviated due to thermal expansion, each steel ball 18 is moved into three sets of position restriction regions. It becomes impossible to pinch at the same time. In this case, one of the steel balls 18 is not stored in a proper position in the position restraining region, the moving frame 14 is lifted from the fixed frame 12, and the locking position of the image blur correction lens 16 is shifted.

Next, the operation of moving the moving frame 14 to the locking position will be described.
First, when the start switch (not shown) for the camera shake prevention function of the camera 1 is turned off or the power switch (not shown) of the camera 1 is turned off, the locking position built in the controller 36 is set. The moving means 37 (FIG. 8) moves the moving frame 14 toward the locking position. That is, the controller 36 switches the changeover switch 45 to the locking position moving means 37 side, and the locking position moving means 37 outputs a coil position command signal for moving the moving frame 14 to the locking position. Specifically, when the locking position moving means 37 gives the same coil position command signal to each of the driving coils 20a, 20b, 20c, the moving frame 14 changes the optical axis of the image blur correction lens 16. Centered, it is rotated clockwise in FIG.

  Accordingly, the fixed frame receiving portions 13a, 13b, and 13c and the moving frame receiving portions 15a, 15b, and 15c are changed from the state shown in FIGS. 11 (a) and 13 (a) to FIGS. 11 (b) and 13 (b). ). Further, the controller 36 sends a signal to a solenoid (not shown) connected to the locking hook 17 (FIG. 2) to energize it, and rotates the locking hook 17 to a position indicated by an imaginary line. .

  When the moving frame 14 is further rotated clockwise and each steel ball 18 reaches the position restraining area and the adjustment area, the controller 36 sends a signal to the second changeover switch 46 (FIG. 8), The changeover switch 46 is changed over to a position where a signal from the locking direction urging means 47 is input to each drive circuit 44a, 44b, 44c. As a result, the outputs of the magnetic sensor amplifiers 42a, 42b, and 42c are disconnected from the inputs to the drive circuits 44a, 44b, and 44c, and the drive coils 20a, 20b, and 20c are connected to the hall elements 24a, 24b, and 24c, respectively. The same current flows regardless of the detection signal. As described in Expression 2, flowing the same current through the drive coils 20a, 20b, and 20c corresponds to driving the moving frame 14 only in the rotation direction. Therefore, after the second changeover switch 46 is switched, the moving frame 14 is driven and controlled only in the rotation direction.

  When the moving frame 14 is further rotated clockwise and reaches the position shown in FIG. 3, the steel balls 18 held between the fixed frame receiving portions 13 a and 13 b and the moving frame receiving portions 15 a and 15 b are respectively positioned in the position restraining regions. It is sandwiched between 52 and 56. On the other hand, the steel ball 18 sandwiched between the fixed frame receiving portion 13c and the moving frame receiving portion 15c is sandwiched between the fixed portion adjustment region 60 and the movable portion adjustment region 64.

  When the moving frame 14 reaches the position shown in FIG. 3, the controller 36 sends a signal to a solenoid (not shown) to stop energization, and rotates the locking hook 17 to the position shown by the solid line in FIG. . As a result, the locking hook 17 attached to the fixed frame 12 and the locking projection 17 a provided on the moving frame 14 are engaged. Here, in the state shown in FIG. 3, the movement of the moving frame 14 relative to the fixed frame 12 is restricted so that only rotational movement is possible by the action of the position restricting regions 52 and 56 and the steel ball 18 sandwiched between them. Has been. In this state, by engaging the locking hook 17 and the locking projection 17a, the rotation of the moving frame 14 is restrained, and the translational movement and the rotational movement of the moving frame 14 are locked.

  Finally, the controller 36 stops energization of the driving coils 20a, 20b, and 20c. Since the moving frame 14 is locked in a state where energization to a solenoid (not shown) is stopped, the moving frame 14 can be maintained at the locked position without consuming electric power.

  In the locking position, each steel ball 18 is positioned between the position restraining regions 52 and 56 formed on a curved surface having substantially the same radius of curvature as the steel ball 18, and the fixed portion adjusting region 60 and the movable portion adjusting region 64. Are sandwiched between them. Accordingly, since the contact area between each steel ball 18 and the fixed frame receiving portion and the moving frame receiving portion is relatively wide, when an impact force acts on the camera 1, the fixed frame receiving portion and the moving frame receiving portion. The pressure acting on is reduced.

  Furthermore, in the locking position, each steel ball 18 is sandwiched between the position restraining regions 52 and 56 and between the fixed portion adjusting region 60 and the movable portion adjusting region 64, so that each steel ball 18 is It is locked in the fixed frame receiving part and the moving frame receiving part and does not rattle. Further, the position of each steel ball 18 in the locking position is constrained in the position constraining region and the adjustment region, and is positioned almost uniquely.

  Next, when returning the moving frame 14 from the locking position to the operation center position, the controller 36 sends a signal to a solenoid (not shown) to energize, and the locking hook 17 is imaginary in FIG. Rotate to the position indicated by. As a result, the engagement between the locking hook 17 and the locking projection 17a is released. Next, the locking position moving means 37 outputs a lens position command signal for rotating the moving frame 14 counterclockwise by a predetermined angle, and returns the moving frame 14 to the operation center position of the image blur prevention control shown in FIG. Let Further, the controller 36 sends a signal to a solenoid (not shown) to stop energization, and rotates the locking hook 17 to the position shown by the solid line in FIG.

  Here, in the locking position, the position of each steel ball 18 is positioned almost uniquely. Further, by rotating the moving frame 14 by a predetermined angle counterclockwise from the locking position, the position where each steel ball 18 rolls and moves is also determined uniquely. Therefore, the position of each steel ball 18 in the rolling region when the actuator 10 is returned to the operation center position can be set at an appropriate position.

  According to the camera of the embodiment of the present invention, at the locking position, the steel ball is sandwiched between the two position restriction regions, so that the movement frame has two points in the radial direction of the circle around the optical axis. Therefore, the translational movement of the moving frame is locked. That is, the translational movement of the moving frame can be locked only by providing the position restraining region in the steel ball receiving portion without providing a special member. Thereby, the moving frame can be locked without increasing the outer diameter of the actuator.

  Further, according to the camera of the embodiment of the present invention, since one steel ball is sandwiched between the fixed portion adjustment region and the movable portion adjustment region, the steel ball sandwiched between them and the optical axis The distance between them can be varied. Accordingly, it is possible to allow an error in the position and size of the position constraint region while reliably positioning the steel ball held between the fixed portion adjustment region and the movable portion adjustment region.

  Furthermore, according to the camera of the embodiment of the present invention, since the position constraint area is configured by a curved surface having substantially the same radius of curvature as the surface of the steel ball, the contact area where the position constraint area contacts the steel ball is widened. The contact pressure can be reduced.

  Further, according to the camera of the embodiment of the present invention, the locking hook locks the rotation of the moving frame with respect to the fixed frame, so that the moving frame is brought into a state in which the translational movement is locked by each position constraint region. Can be maintained.

  Furthermore, according to the camera of the embodiment of the present invention, when the moving frame is moved to the locking position, the second changeover switch is switched and the moving frame is driven by the locking direction biasing means. For this reason, the moving frame is biased so that the moving frame is rotated in the locking direction by the output of the locking direction biasing means regardless of the position signal output from the Hall element. As a result, it is possible to prevent an excessive current from flowing through the driving coil by generating a driving force in a direction in which the movement of the moving frame is restrained, and to move the moving frame in the locking direction with an appropriate current. Can be energized.

  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 film camera. However, the present invention can be applied to any camera for capturing a still image or a moving image, such as a digital camera or a video camera.

  Further, in the above-described embodiment, three steel balls are sandwiched between two sets of position restriction areas and one set of adjustment areas. However, three or more steel balls may be used, and adjustment areas are omitted. Then, two or more sets of position constraint areas may be provided.

  Further, in the embodiment described above, the rotation of the moving frame is locked by the locking hook. However, as the rotation locking means, a shaft extending from the fixed frame to the moving frame is provided at the time of locking, and the movement is performed. You may provide the frame with the recessed part or hole which receives this shaft.

  In the above-described embodiment, the rolling region defining wall, the restraining region defining wall, and the like are formed by forming the recesses in the fixed frame and the moving frame. You may form so that it may protrude from.

It is sectional drawing of the camera by embodiment of this invention. FIG. 6 is a front view of an actuator having a moving frame at an operation center position of image blur prevention control. It is a front view of an actuator in which a moving frame is in a locking position. It is side surface sectional drawing which follows the IV-IV line of FIG. (A) Side surface sectional drawing which follows the VV line | wire of FIG. 2, (b) It is a perspective view which shows the state of the magnetization of the magnet for a drive. It is a figure explaining the relationship between the movement of a drive magnet, and the signal output from a Hall element. It is a figure explaining the relationship between the movement of a drive magnet, and the signal output from a Hall element. It is a block diagram which shows the signal processing in a controller. It is a figure which shows the positional relationship of the drive coil arrange | positioned on the fixed frame, and the drive magnet arrange | positioned on the moving frame. (A) Front view of fixed frame receiving part formed in fixed frame, (b) Cross-sectional view along line bb in (a), (c) Cross-sectional view along line cc in (a). . It is a figure which shows the positional relationship of the fixed frame receiving part formed in the fixed frame, and the moving frame receiving part formed in the moving frame, (a) Operation center position of image blur correction control, (b) To locking position The transition state, (c) shows the locking position. It is sectional drawing which follows the (a) front view of a fixed frame receiving part, (b) and the bb line in (a), and (c) and the cc line in (a). It is a figure which shows the positional relationship of a fixed frame receiving part and a moving frame receiving part, (a) Operation center position of image blurring correction control, (b) Transition state to locking position, (c) Locking position is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Camera of embodiment of this invention 2 Lens unit 4 Camera main body 6 Lens barrel 8 Imaging lens 10 Actuator 12 Fixed frame (fixed part)
13a, 13b, 13c Fixed frame receiving part 14 Moving frame (movable part)
15a, 15b, 15c Moving frame receiving portion 16 Image blur correction lens 17 Locking hook (rotation locking means)
17a Locking projection 18 Steel ball (spherical body)
20a, 20b, 20c Driving coil 22a, 22b, 22c Driving magnet 24a, 24b, 24c Hall element 26 Suction yoke 28 Back yoke 34a, 34b Gyro 36 Controller 37 Locking position moving means 38a, 38b Arithmetic circuit 40a, 40b , 40c Arithmetic circuits 42a, 42b, 42c Magnetic sensor amplifiers 44a, 44b, 44c Drive circuit 45 Changeover switch 46 Second changeover switch 47 Locking direction biasing means 50 Rolling region 50a Fixed portion rolling region demarcating wall 52 Position constraint region 52a Fixed part restraining area defining wall 54 Rolling area 54a Moving part rolling area defining wall 56 Position restraining area 56a Moving part restraining area defining wall 58 Rolling area 58a Fixed part rolling area defining wall 60 Fixed part adjusting area 60a Fixed part Adjustment area demarcating wall 62 Rolling area 62a Moving section rolling region defining wall 64 movable portion adjustment region 64a movable portion adjustment region defining wall

Claims (7)

An actuator for moving an imaging lens within a plane perpendicular to the optical axis to prevent image blur;
A fixed part;
A movable part to which the imaging lens is attached;
At least three spherical bodies that are sandwiched between the movable portion and the fixed portion and support the movable portion movably;
Drive means for translating and rotating the movable part relative to the fixed part;
A fixed portion rolling region defining wall that is provided in the fixed portion so as to surround each spherical body, and defines a rolling region in which the spherical body can roll in an arbitrary direction;
A movable part rolling region defining wall provided in the movable part so as to surround each of the spherical bodies, and defining a rolling region in which the spherical body can roll in an arbitrary direction;
A position constraining region that is formed so as to extend in a substantially tangential direction of a circle centered on the optical axis continuously to the rolling region of the fixed part, and restrains the distance from the optical axis to the spherical body to a predetermined distance. At least two fixed part restraining region defining walls that define
Corresponding to each of these fixed portion restricting region defining walls, a movable portion restricting region for defining a position restricting region extending in a substantially tangential direction of a circle centered on the optical axis so as to be continuous with the rolling region of the movable portion. A demarcating wall;
An actuator comprising:   Furthermore, a fixed portion adjustment region defining wall that defines a linear fixed portion adjustment region that extends continuously from the rolling region of the fixed portion, and a linear movable portion adjustment that extends continuously from the rolling region of the movable portion. A movable portion adjustment region defining wall for defining a region, and at least one of the fixed portion adjustment region and the movable portion adjustment region is defined so as to intersect a circumference of a circle centering on the optical axis. The actuator according to claim 1.   Three sets of the fixed portion rolling region defining wall and the movable portion rolling region defining wall are formed, two of these are formed with the position constraint region, and the other set is formed with the fixed portion adjusting region. The actuator according to claim 2, wherein the movable part adjustment region is formed.   The surface of the spherical body, which is surrounded by the fixed portion restraining region defining wall or the movable portion restraining region defining wall, is in contact with the spherical body, and has a curved surface having substantially the same radius of curvature as the surface of the spherical body. The actuator according to any one of claims.   Furthermore, the spherical body has a rotation locking means for locking the rotation of the movable part with respect to the fixed part in a state where the spherical body is located in each position restriction region of the fixed part and the movable part. The actuator according to any one of claims. A lens barrel;
A plurality of imaging lenses housed in the lens barrel;
The actuator according to any one of claims 1 to 5, wherein a part of the imaging lens is attached to the movable part,
A lens unit comprising: The camera body,
A lens unit according to claim 6;
A camera characterized by comprising:

Images