JP6009955B2 - Lens drive device - Google Patents

Description

  The present invention relates to a lens driving device that performs image blur correction by moving a lens in a direction orthogonal to an optical axis.

  Conventionally, there is JP-A-2008-191266 as a technical document in such a field. This publication discloses a first electric actuator that moves a moving frame that holds a lens in a first direction perpendicular to the optical axis with respect to the support frame, and a moving frame that is orthogonal to the optical axis with respect to the support frame; A lens driving device is described that includes a second electric actuator that moves in a second direction orthogonal to the first direction. Each of the first and second electric actuators includes a magnet, a coil, and a counter yoke. The magnet is provided on the moving frame, and the coil and the counter yoke are provided on the support frame. Moreover, this opposing yoke is formed in the flat plate shape which comprises a square.

JP 2008-191266 A

  By the way, in the lens driving device as described above, the moving frame that holds the lens is supported by the support frame. However, after the image blur correction is performed, it is necessary to return the moving frame to the support frame. Therefore, it is conceivable that a magnet is disposed on one of the moving frame and the supporting frame, a coil and a magnetic body are disposed on the other, and the magnet is attracted to the magnet to give a center returning force to the moving frame. However, the magnetic attraction force acting between the magnet and the magnetic body has a component in the optical axis direction and a component in the orthogonal direction orthogonal to the optical axis, and two directions are used when adjusting the center return force. The magnetic attraction force must be controlled, so that it is difficult to adjust the magnetic attraction force.

  Accordingly, an object of the present invention is to provide a lens driving device that can easily adjust a magnetic attractive force acting between a magnet and a magnetic body.

  In order to solve the above-described problems, the present invention provides a lens driving device having a lens holding frame that holds a lens and is movably supported in a plane perpendicular to the optical axis in the frame, and includes a magnet, a coil, and a coil. In cooperation, the drive unit that moves the lens holding frame in a plane perpendicular to the optical axis, and a magnet with a plate-like magnetic body facing the magnet in the direction of the optical axis with the coil interposed therebetween, The magnetic body has a concave portion formed in a concave shape from the peripheral edge toward the center of gravity, and the magnetic body is line-symmetric with respect to a straight line passing through the center of gravity of the magnetic body on a plane orthogonal to the optical axis. It is characterized in that two recesses are provided at opposing positions.

  According to the lens driving device of the present invention, the magnetic body has two recesses formed in a concave shape toward the center of gravity of the magnetic body so as to be axisymmetric with respect to a straight line passing through the center of gravity of the magnetic body. ing. Here, for example, as described above, when the magnetic body has a rectangular plate shape, the magnetic attraction force by the magnet and the magnetic body has a component in the optical axis direction and a component in the orthogonal direction. . In addition, in a flat plate-shaped magnetic body having a quadrangular shape, increasing the size of the magnetic body increases both the component of the magnetic attraction force in the optical axis direction and the component in the orthogonal direction, and decreasing the size of the magnetic body decreases the direction of the optical axis. Both the component and the component in the orthogonal direction are reduced. Therefore, in a flat plate-shaped magnetic body having a quadrangular shape, the component in the optical axis direction cannot be made larger or smaller than the component in the orthogonal direction, so the magnetic attractive force acting between the magnet and the magnetic body Is difficult to adjust. For example, even if the shape of the magnetic body on the plane orthogonal to the optical axis is the same as the shape of the magnet, the magnetic attraction force by the magnet and the magnetic body has components in two directions. Adjustment is difficult. On the other hand, in the present invention, since the magnetic body has two recesses formed in a concave shape toward the center of gravity so as to be axisymmetric with respect to a straight line passing through the center of gravity of the magnetic body, By the recess, the component in the direction perpendicular to the optical axis in the magnetic attraction force by the magnet and the magnetic body can be relatively reduced. In this way, by adjusting the magnetic attraction force by reducing the component in the direction perpendicular to the optical axis relative to the component in the optical axis direction of the magnetic attraction force, only the magnetic attraction force acting in the optical axis direction is adjusted. Control will be better. Therefore, the magnetic attractive force can be easily adjusted.

Moreover, on the plane orthogonal to the optical axis, the respective recessed portions are juxtaposed on a straight line connecting the center of gravity of the magnetic body and the optical axis, or on a straight line perpendicular to the direction in which the straight line extends.
When the recesses are juxtaposed on a straight line connecting the center of gravity of the magnetic body and the optical axis, out of the components of the magnetic attraction force in the direction perpendicular to the optical axis, the linear direction connecting the center of gravity of the magnetic body and the optical axis Ingredients can be made smaller. In addition, when the dents are juxtaposed on a straight line extending in a direction perpendicular to the straight line connecting the center of gravity of the magnetic body and the optical axis, the magnetic body out of the components of the magnetic attraction force in the direction perpendicular to the optical axis The component in the direction in which a straight line extending perpendicularly to the straight line connecting the center of gravity and the optical axis can be further reduced.

  According to the present invention, it is possible to easily adjust the magnetic attractive force acting between the magnet and the magnetic body.

It is a perspective view which shows one Embodiment of the lens drive device which concerns on this invention. It is a perspective view which shows the state which removed the cover part of the lens drive device of FIG. It is a disassembled perspective view which shows the lens drive device of FIG. It is a disassembled perspective view which shows the lens drive device of FIG. It is a perspective view which shows a movable frame and FPC. It is sectional drawing which shows a base part and a movable frame. It is sectional drawing which shows a movable frame and a lens holding frame. It is the perspective view and top view which show a magnet, a coil, and a return yoke. It is the perspective view and top view which show a magnet, a coil, and a return yoke. It is a graph which shows the relationship between the length between the hollow parts of a return yoke, and center return force. It is the perspective view and top view which show a magnet, a coil, and a return yoke. It is the perspective view and top view which show a magnet, a coil, and a return yoke.

  Hereinafter, a preferred embodiment of a lens driving device according to the present invention will be described in detail with reference to the drawings.

  The lens driving device shown in FIG. 1 is used in a digital camera, a mobile phone, a smartphone, or the like that performs image blur correction, and is a CCD [Charge Coupled Device] image sensor or a CMOS [Complementary Metal Oxide Semiconductor] image sensor that is an image pickup device. It is placed in front and used.

  As shown in FIGS. 1 to 3, the lens driving device 1 includes a rectangular parallelepiped lid body 2, a rectangular base portion 3 for closing the opening of the lid body 2, and a focus adjustment unit that performs focus adjustment. A flexible printed circuit board for focus adjustment (hereinafter referred to as FPC) 5 for ensuring electrical connection between the drive unit 4 and an external circuit, an image blur correction drive unit (drive unit) 6 and an external circuit FPC 7 for image blur correction for securing the electrical connection of the lens, and a substantially cylindrical lens barrel 8 that houses at least one lens R.

  The lid 2 is a box-shaped member having a circular opening 2a centered on the optical axis C of the lens R, and the base 3 is a rectangular frame having a circular opening 3a centered on the optical axis C. Shaped member. The lens barrel 8 holds the lens R in a state where the lens R is exposed from the opening 2 a of the lid 2 and the opening 3 a of the base 3. The base 3 has a protrusion 3b that protrudes from one side of the peripheral edge of the base 3 in the direction of the optical axis C. A rectangular opening 3c is formed at the center of the protrusion 3b. Yes. An H-shaped resin insulating plate 9 fixed to the front end portion 5a of the FPC 5 enters the opening 3c, and the resin insulating plate 9 closes the opening 3c.

  As shown in FIG. 2, the FPC 7 has an extension portion 7 c extending outward from the lid body 2 and the base portion 3, and a bifurcated portion that is divided into two forks in the vicinity of the lid body 2 and the base portion 3. 7a. The bifurcated portion 7 a of the FPC 7 is fixed by being sandwiched between the locking projections 3 g of the base portion 3 inside the lid body 2. Further, the inner end of each of the branch portions 7a is fixed to a movable frame (frame body) 10, and the first magnet 6a of the image blur correction driving unit 6 is disposed on the outer side of the tip portion 7b (see FIG. 3). And a plate-like return yoke (magnetic body) 11 that amplifies the attractive force of the second magnet 6b. A Hall element 12 for magnetic detection is fixed to the surface opposite to the surface to which the return yoke 11 is fixed at the tip 7b of the branch portion 7a of the FPC 7.

  The movable frame 10 is supported by the base portion 3 so as to be movable in the direction of the optical axis C. As shown in FIGS. 3 to 5, the movable frame 10 includes a circular opening 10 a centered on the optical axis C, an oval coil loading portion 10 b formed at each corner on one side, and a movable frame 10. It has three ball mounting recesses 10c (see FIG. 5) into which the sphere 13 formed on the outer peripheral surface of the frame 10 enters. The lens barrel 8 enters the opening 10 a of the movable frame 10, and the coil loading unit 10 b of the movable frame 10 includes a first coil 6 c that forms an ellipse of the image blur correction drive unit 6 and The second coil 6d is fitted and fixed. The movable frame 10 includes a magnet holding portion 10e that protrudes in the direction of the optical axis C on one side of the peripheral edge of the movable frame 10, and a magnet holding portion 10e that is a corner of the movable frame 10 with the optical axis C interposed therebetween. And two projecting portions 10f provided on the opposite side.

  The magnet holding part 10e of the movable frame 10 is formed in a crescent shape as viewed from the optical axis C direction, and the column parts 10g formed at both ends of the magnet holding part 10e are notched in a semi-cylindrical shape on the outer side. A ball receiving portion 10h that extends in the direction of the optical axis C is provided. Two spheres 15 enter one sphere receiving portion 10h, and one sphere 15 enters the other sphere receiving portion 10h, but two spheres 15 enter the other sphere receiving portion 10h. One sphere 15 may enter one of the ball receiving portions 10h.

  By the way, as shown in FIG. 4, the support portions 3 f formed at both ends of the protruding portion 3 b of the base portion 3 are formed with ball receiving portions 3 d cut out in a semi-cylindrical shape at three locations. Each ball receiving portion 3 d of the base portion 3 is formed at a position corresponding to the ball receiving portion 10 h of the movable frame 10. As shown in FIG. 6, the base portion 3 is formed with a fitting recess 3e for fitting the coil 4a and the yoke 16 inside the protrusion 3b of the base portion 3, and this fitting recess 3e. The coil 4a of the focus adjustment drive unit 4 and the two yokes 16 are fitted to each other. The coil 4a of the focus adjustment drive unit 4 has a central part 4b that forms an upper bottom part of a trapezoid when viewed from the optical axis C direction, and end parts 4c that are respectively located on both sides of the central part 4b. 4c is bent about 45 degrees inward with respect to the central portion 4b. The yokes 16 are disposed outside the end portions 4c of the coils 4a.

  Further, as shown in FIG. 5, a flat magnet fixing portion 10 i and a magnet fixing portion 10 j formed at an inclination of 45 degrees with respect to the magnet fixing portion 10 i are formed on the outer periphery of the magnet holding portion 10 e of the movable frame 10. And a magnet fixing portion 10k formed to be inclined by 45 degrees on the opposite side of the magnet fixing portion 10j with respect to the magnet fixing portion 10i. Magnets 4d, 4e, and 4f of the focus adjustment drive unit 4 are fixed to the magnet fixing units 10i, 10j, and 10k, respectively. In the state where the movable frame 10 is held by the base portion 3, as shown in FIG. 6, the central portion 4b of the trapezoidal coil 4a faces the outside of the magnet 4d, and the coil 4a is outside the magnets 4e and 4f. Each end 4c faces each other.

  In addition, a hall element 17 (see FIG. 3), which is a magnetic field detection element, is disposed inside the central portion 4b of the coil 4a, and the hall element 17 is fixed to the tip portion 5a of the FPC 5. Two iron leads 18 extending from the central portion 4b to the end portion 4c of the coil 4a are disposed on both ends of the hall element 17, and the end portion 18a of the lead 18 on the end portion 4c side of the coil 4a is disposed. 6 is electrically connected to the coil wire of the end 4c in a state of extending outside the end 4c of the coil 4a, as shown in FIG.

  By the cooperation of the coil 4a and the magnets 4d, 4e, and 4f, the movable frame 10 can move in the direction of the optical axis C with respect to the base unit 3 to adjust the focal point and change the focal length. It becomes. Further, since the yoke 16 is provided outside the end portion 4c of the coil 4a, the yoke 16 fitted to the base portion 3 is attracted to the magnets 4e and 4f fixed to the movable frame 10, and the movable frame 10 is A magnetic attractive force in a direction perpendicular to the optical axis C with respect to the base portion 3 is generated. Further, the base portion 3 and the movable frame 10 attract each other with the sphere 15 interposed between the ball receiving portion 10h (see FIG. 5) of the movable frame 10 and the ball receiving portion 3d (see FIG. 4) of the base portion 3. Accordingly, the movable frame 10 is slidably supported by the base portion 3 via the sphere 15.

  As shown in FIGS. 4 and 5, the two protrusions 10 f provided at the corners of the movable frame 10 are engaged for joining the pressing plate 21 that prevents the lens holding frame 20 from being lifted. A protrusion 10m is provided. Engagement protrusions 10n for joining the pressing plates 21 are provided on the support pillars 10g of the magnet holding part 10e provided on the opposite side across the optical axis C of the protrusion 10f of the movable frame 10. The engaging protrusions 10m and 10n of the movable frame 10 are engaged with the engaging holes 21a and 21b of the pressing plate 21, respectively. Thereby, the movable frame 10 and the pressing plate 21 are fixed in a state where the lens holding frame 20 is sandwiched.

  As shown in FIG. 7, the lens holding frame 20 that holds the lens barrel 8 is supported so as to be movable in the direction perpendicular to the optical axis C with respect to the movable frame 10. The lens holding frame 20 includes a circular opening 20a into which the lens barrel 8 is fitted, a magnet fitting hole 20b for fixing the magnets 6a and 6b of the image blur correction drive unit 6, and the lens holding frame 20 to the movable frame 10. The first to third suction magnets 51, 52, 53 for supporting the magnets are provided with magnet fitting recesses 20 c and ball receiving recesses 20 d (see FIG. 4) for receiving the spheres 13.

  Two magnet fitting holes 20b of the lens holding frame 20 are provided at positions corresponding to the coil loading portions 10b (see FIG. 6) of the movable frame 10. The first magnet 6a fitted in the magnet fitting hole 20b faces the first coil 6c fitted in the coil loading portion 10b in the direction of the optical axis C, and the second magnet 6a fitted in the magnet fitting hole 20b. The magnet 6b faces the second coil 6d fitted in the coil loading portion 10b in the direction of the optical axis C. The lens holding frame 20 is arranged in a direction orthogonal to the optical axis C with respect to the movable frame 10 by the cooperation of the first magnet 6a and the coil 6c and the cooperation of the second magnet 6b and the second coil 6d. It is possible to perform image blur correction by moving.

  Three magnet fitting recesses 20c of the lens holding frame 20 are provided, and first to third attracting magnets 51, 52, and 53 magnetized with four poles are fitted into the respective magnet fitting recesses 20c. Further, as shown in FIG. 5, the movable frame 10 has metal piece insertion portions 10 d that are holes for inserting the first to third iron pieces 41, 42, 43 having a fork shape in three places. Each of the metal piece insertion portions 10 d is provided at a position corresponding to the magnet fitting recess 20 c of the lens holding frame 20. The first to third suction magnets 51, 52, 53 fitted in the magnet fitting recess 20 c of the lens holding frame 20 are the first to third iron pieces 41 inserted into the metal piece insertion part 10 d of the movable frame 10. , 42 and 43 face the optical axis C direction. Therefore, when the lens holding frame 20 is disposed on the movable frame 10, the magnetic attractive force generated by the first to third attractive magnets 51, 52, 53 and the first to third iron pieces 41, 42, 43. Thus, the lens holding frame 20 and the movable frame 10 are attracted to each other.

  As shown in FIG. 7, the first suction portion 31 is configured by the first suction magnet 51 and the first iron piece 41, and the second suction portion 32 is formed by the second suction magnet 52 and the second iron piece 42. The third suction part 33 is configured by the third suction magnet 53 and the third iron piece 43. The magnetic attractive force generated by the first to third attractive portions 31, 32 and 33 is stronger than the magnetic attractive force generated by the magnets 6 a and 6 b and the return yoke 11 of the image shake correcting drive unit 6. . Therefore, when the lens holding frame 20 is moved in the direction orthogonal to the optical axis C with respect to the movable frame 10, the lens holding frame 20 can be reliably moved to the center position in the movable frame 10.

  As shown in FIG. 4, three ball receiving recesses 20 d of the lens holding frame 20 are provided at positions corresponding to the ball mounting recesses 10 c (see FIG. 5) of the movable frame 10. In a state where the lens holding frame 20 is disposed on the movable frame 10, a space large enough to accommodate the sphere 13 is formed by the ball receiving recess 20 d of the lens holding frame 20 and the ball mounting recess 10 c of the movable frame 10. The The lens holding frame 20 is supported by the sphere 13 so as to be movable with respect to the movable frame 10 by inserting the sphere 13 into the space formed by the ball receiving recess 20d and the ball mounting recess 10c. Further, when three spheres 13 are connected in a plane orthogonal to the optical axis C, an isosceles triangle is formed, and the lens holding frame 20 is supported by the movable frame 10 at three points. Therefore, the lens holding frame 20 can be moved with respect to the movable frame 10 in a stable state.

  Further, as shown in FIG. 3, a back yoke 25 having a crescent shape when viewed from the optical axis C direction is provided on the side of the holding plate 21 of the lens holding frame 20 in the optical axis C direction. The back yoke 25 is in close contact with the magnets 6a, 6b, 51, 52, 53 (see FIG. 7) of the lens holding frame 20 at the time of assembly.

  Next, the operation of the lens holding frame 20 will be described.

  If camera shake occurs when shooting with a device (for example, a camera) in which the lens driving device 1 is incorporated, the position of the optical axis C may change. In this case, a camera shake detection sensor such as a gyro sensor detects camera shake, and the control means (not shown) sends the drive signal of the lens holding frame 20 via the FPC 7 so that the position of the optical axis C is maintained at a predetermined position. Output to the coils 6c and 6d.

  Then, as shown in FIG. 7, the first magnet 6a and the first coil 6c generate a driving force F1 that works in the direction of a straight line connecting the first magnet 6a and the center O of the lens R, and the lens The holding frame 20 is moved with respect to the movable frame 10 in the direction in which the driving force F1 acts. The second magnet 6b and the second coil 6d generate a driving force F2 that works in a direction of a straight line connecting the second magnet 6b and the center O, and drive the lens holding frame 20 to the movable frame 10 with a driving force F2. Move in the direction that works. By the movement of the lens holding frame 20 in the direction in which the driving forces F1 and F2 work, the position of the optical axis C is moved to a fixed position, and camera shake is corrected.

  Hereinafter, with respect to the return yoke 11, as shown in FIGS. 7 and 8, the direction in which the first straight line S1 connecting the center O of the lens R and the center of gravity X1 of the return yoke 11 extends is defined as the X direction and the optical axis C. A direction in which the second straight line S2 perpendicular to the first straight line S1 extends in a plane orthogonal to the Y direction will be described. By the way, as shown in FIGS. 8A and 8B, the second magnet 6b disposed in the lens holding frame 20 and the ellipse-shaped long side disposed in the movable frame 10 have the Y direction. And the return yoke 11 fixed to the FPC 7 are arranged side by side in the Z direction in which the optical axis C extends. The N pole and S pole of the second magnet 6b are opposed to the long sides of the second coil 6d. Similarly, the first magnet 6a, the first coil 6c, and the return yoke 11 of the image blur correction drive unit 6 are arranged side by side in the Z direction. Further, due to the cooperation between the first magnet 6a and the return yoke 11 and the cooperation between the second magnet 6b and the return yoke 11, a center return force of the lens holding frame 20 with respect to the movable frame 10 is generated. Yes.

  As shown in FIGS. 8A and 8B, the return yoke 11 includes a first recess 61 and a second recess that are formed in a concave shape from the periphery of the return yoke 11 toward the center of gravity X1. It has a ribbon shape having 62. The return yoke 11 has an axisymmetric shape with respect to the first straight line S1 passing through the center of gravity X1 of the return yoke 11 on a plane orthogonal to the optical axis C, and the first and second depressions. The parts 61 and 62 are provided at two positions facing each other. The first and second depressions 61 and 62 are juxtaposed on a second straight line S2 perpendicular to the first straight line S1 connecting the center of gravity X1 of the return yoke 11 and the optical axis C.

  On the plane orthogonal to the optical axis C, the first hollow portion 61 of the return yoke 11 has a trapezoidal shape, and the first hollow portion 61 has an upper bottom portion 61a and slopes located on both sides of the upper bottom portion 61a. Part 61b. In the hollow portion 61, each inclined portion 61b is inclined about 45 degrees with respect to the straight line S1. Further, the upper bottom portion 61a of the first hollow portion 61 extends in the X direction in which the first straight line S1 extends.

  The second depression 62 of the return yoke 11 is symmetrical with the first depression 61 with respect to the first straight line S1 passing through the center of gravity X1 of the return yoke 11 on a plane orthogonal to the optical axis C. It is formed to become. The second hollow portion 62 of the return yoke 11 has an upper bottom portion 62 a and an inclined portion 62 b having the same shape as the first hollow portion 61. In other words, the first and second depressions 61 and 62 pass through the center of gravity X1 and the lens holding frame 20 is moved by the second magnet 6b and the second coil 6d that are paired with the return yoke 11. It is formed so as to be symmetric with respect to the first straight line S1 parallel to the direction.

  As a modified example, as shown in FIGS. 9A and 9B, a return yoke in which first and second hollow portions 161 and 162 are juxtaposed in the X direction instead of the return yoke 11 described above. 111 can be used. The return yoke 111 includes first and second depressions 161 and 162 that are formed in a concave shape toward the center of gravity X2 of the return yoke 111. The first depression 161 of the return yoke 111 has a trapezoidal shape, and the first depression 161 has an upper bottom 161a and inclined portions 161b located on both sides of the upper bottom 161a. In the recessed portion 161 of the return yoke 111, each inclined portion 161b is inclined by about 45 degrees with respect to the straight line S2, and the upper bottom portion 161a of the first recessed portion 161 extends in the Y direction. The second depression 162 of the return yoke 111 is formed so as to be symmetrical with the first depression 161 with respect to a second straight line S2 that passes through the center of gravity X2 of the return yoke 111 and extends in the Y direction. The second hollow portion 162 of the return yoke 111 has an upper bottom portion 162 a and an inclined portion 162 b having the same shape as the first hollow portion 161. In other words, the first and second depressions 161 and 162 move through the center of gravity X2 and the lens holding frame 20 is moved by the second magnet 6b and the second coil 6d that are paired with the return yoke 111. It is formed to be line symmetric with respect to the second straight line S2 perpendicular to the direction.

  Next, the return yoke 11 in which the recessed portions 61 and 62 are juxtaposed in the Y direction in which the second straight line S2 shown in FIG. 8 extends, and the X direction in which the first straight line S1 shown in FIG. 9 extends. The center return force of the lens holding frame 20 with respect to the movable frame 10 when using the return yoke 111 in which the recessed portions 161 and 162 are juxtaposed is described with reference to the graph of FIG.

  L1 in FIG. 10 is a line connecting the midpoint M1 of the upper bottom portion 61a of the first hollow portion 61 and the midpoint M2 of the upper bottom portion 62a of the second hollow portion 62 in the return yoke 11 shown in FIG. Indicates the length of the minute. L2 in FIG. 10 is a line connecting the middle point N1 of the upper bottom part 161a of the first depression part 161 and the middle point N2 of the upper bottom part 162a of the second depression part 162 in the return yoke 111 shown in FIG. Indicates the length of the minute. 10A shows the relationship between the X-direction center return force and the recess separation distance L1 when the return yoke 11 shown in FIG. 8 is used, and FIG. 10B shows the return yoke 11 shown in FIG. FIG. 10C shows the relationship between the center return force in the Y direction and the recess separation distance L1 when used, and FIG. 10C shows the center return force in the X direction and the recess separation distance when the return yoke 111 of FIG. 9 is used. FIG. 10 (d) shows the relationship between the center return force in the Y direction and the distance L2 of the recess when the return yoke 111 of FIG. 9 is used.

  As shown in FIGS. 10 (a) and 10 (b), when the return yoke 11 of FIG. 8 is used, if the amount of depression in the Y direction is increased and the separation distance L1 of the depression is shortened, The center return force in the Y direction decreases rapidly, and the center return force in the X direction also decreases gradually. On the other hand, as shown in FIGS. 10C and 10D, when the return yoke 111 of FIG. 9 is used, the amount of depression in the X direction is increased and the distance L2 between the depressions is shortened. Then, the center return force in the X direction decreases rapidly, and the center return force in the Y direction also decreases gradually. At this time, the amount of attraction force in the Z direction, that is, the optical axis C direction can be maintained without being greatly reduced. As described above, when the return yoke 111 of FIG. 9 in which the depressions 161 and 162 are juxtaposed in the X direction is used, among the components in the direction perpendicular to the optical axis C in the magnetic attraction force, the X direction component is further reduced. can do. Further, when the return yoke 11 of FIG. 8 in which the recessed portions 61 and 62 are juxtaposed in the Y direction is used, among the components in the direction perpendicular to the optical axis C in the magnetic attraction force, the component in the Y direction is further reduced. Can do.

  As described above, in the lens driving device 1, as shown in FIG. Two are provided so as to be line symmetric with respect to S1. And by these hollow parts 61 and 62, the component in the direction orthogonal to the optical axis C in the magnetic attraction force by the second magnet 6b and the return yoke 11 of the image blur correction drive part 6 can be made relatively small. it can. In this way, when the magnetic attraction force is adjusted by reducing the component in the direction perpendicular to the optical axis C with respect to the component in the optical axis C direction of the magnetic attraction force, the magnetic attraction acting in the optical axis C direction is adjusted. Control only the force. Therefore, the magnetic attractive force can be easily adjusted. Note that the same effect as described above can be obtained by the relationship between the first magnet 6 a of the image blur correction drive unit 6 and the return yoke 11.

  The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention.

  Although the return yoke 11 has the trapezoidal depressions 61 and 62 symmetrically, as shown in FIGS. 11A and 11B, the return yoke 11 has the semicircular depressions 261 and 262. The yoke 211 may be used. Further, as shown in FIGS. 12A and 12B, a return yoke 311 having semi-elliptical recesses 361 and 362 may be used.

  Further, the direction X in which the first straight line S1 connecting the center of the lens and the center of gravity of the return yoke extends and the moving direction F2 of the lens holding frame by the magnet and coil paired with the return yoke were the same direction. It may be in a different direction.

  The lens holding frame 20 is supported so as to be movable in the direction orthogonal to the optical axis C with respect to the movable frame 10, but is supported so as to be movable in the direction orthogonal to the optical axis C with respect to the base portion 3 forming the frame. May be. Further, the lens R may be held with respect to the lens holding frame 20 so as to be movable in the direction of the optical axis C.

DESCRIPTION OF SYMBOLS 1 ... Lens drive device, 6 ... Drive part, 6a, 6b ... Magnet, 6c, 6d ... Coil, 10 ... Movable frame (frame body) 11, 111, 211, 311 ... Return yoke (magnetic body), 20 ... Lens Holding frame, 61, 62, 161, 162, 261, 262, 361, 362... Depression, C ... optical axis, R ... lens, S1, S2 ... straight line, X1, X2 ... center of gravity.

Claims (5)

A lens driving device having a lens holding frame that holds a lens and is movably supported in a plane perpendicular to the optical axis in the frame,
A driving unit that moves the lens holding frame in a plane perpendicular to the optical axis in cooperation with a magnet and a coil;
A plate-like magnetic body facing the magnet in the direction of the optical axis with the coil interposed therebetween,
Magnetic attraction having an attraction magnet provided on one of the frame and the lens holding frame and a metal piece provided on the other, and attracting the attraction magnet and the metal piece in the optical axis direction A suction unit that generates a restoring force for moving the lens holding frame in a plane perpendicular to the optical axis to a center position in the frame by force , and
The magnetic body has a recess formed in a concave shape from the periphery to the center of gravity to relatively reduce the component in the direction perpendicular to the optical axis in the magnetic attraction force by the magnet of the drive unit and the magnetic body. has,
The lens driving device according to claim 1, wherein a magnetic attraction force generated by the attraction unit is stronger than a magnetic attraction force generated by the magnet of the driving unit and the magnetic body . The lens driving device according to claim 1, wherein the suction unit and the driving unit are arranged so as not to overlap in a plane orthogonal to the optical axis. A base portion that supports the frame body movably in the optical axis direction;
A frame body driving unit that moves the frame in the optical axis direction in cooperation with the magnet and the coil;
The drive unit is provided on one side of the lens in a plane orthogonal to the optical axis,
The lens driving device according to claim 1, wherein the frame driving unit is provided on one side of the lens in a plane orthogonal to the optical axis. The plane is perpendicular to the optical axis, and the magnetic body has a line-symmetric shape with respect to a straight line passing through the center of gravity of the magnetic body, and the recesses are provided at two positions facing each other. The lens driving device according to any one of 1 to 3. On the plane orthogonal to the optical axis, the recesses are juxtaposed on a straight line connecting the center of gravity of the magnetic body and the optical axis, or on a straight line perpendicular to the direction in which the straight line extends. claims 1, characterized in that that to the lens driving device according to any one of 4.

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