JP2012198272A - Lens drive device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lens drive device able to efficiently transmit a driving force from an actuator to a lens holder.SOLUTION: The lens drive device 1 comprises a lens holder 30; a shaft 15; a piezoelectric actuator 50; and biasing members (ball member 71 and retainer 73). The shaft 15 supports the lens holder 30 so as to be movable in the optical axis direction OA of a lens and so as to be able to swing around the axis. The piezoelectric actuator 50 applies a driving force to the lens holder 30 so as to move the lens holder 30 in the optical axis direction OA. The biasing member applies a biasing force F by abutting on the lens holder 30 so as to rotate the lens holder 30 toward the piezoelectric actuator 50.

Description

  The present invention relates to a lens driving device that drives a camera lens mounted on, for example, a mobile phone.

  The lens drive device includes a lens holder for holding the lens, a shaft for guiding the lens holder, an actuator for moving the lens holder along the shaft, and a pressure contact surface for pressure contact with the actuator. Is known (for example, see Patent Document 1). In the lens driving device described in Patent Document 1, in order to press the actuator against the pressing surface, an urging member (between the lens holder and the actuator, or between the actuator and the fixed portion of the lens driving device). Spring) is arranged.

Japanese Patent Laid-Open No. 10-90584

  However, the lens driving device described in Patent Document 1 has the following problems.

  When the urging member is disposed between the lens holder and the actuator, the urging means is located on the driving force transmission path from the actuator to the lens holder. For this reason, a loss occurs in the transmission of the driving force from the actuator to the lens holder, and it may be difficult to move the lens holder appropriately. Even when the urging member is disposed between the actuator and the fixed portion, the urging means is substantially located on the driving force transmission path from the actuator to the lens holder. In this case, the actuator itself vibrates by the biasing means, and it is difficult to appropriately transmit the driving force of the actuator to the lens holder, and there is a possibility that a loss occurs in the transmission of the driving force from the actuator to the lens holder.

  An object of the present invention is to provide a lens driving device capable of efficiently transmitting a driving force from an actuator to a lens holder.

  The lens driving device according to the present invention includes a lens holder for holding the lens, a shaft that supports the lens holder so as to be movable in the optical axis direction of the lens and swingable around the axis, and the lens holder in the optical axis direction. And an urging member that abuts against the lens holder and applies an urging force so as to rotate the lens holder toward the actuator side. .

  In the lens driving device according to the present invention, the urging member abuts against the lens holder to apply the urging force so as to rotate the lens holder toward the actuator. For this reason, the contact state between the lens holder and the actuator is kept good. The urging member is not positioned on the driving force transmission path from the actuator to the lens holder. As a result, the driving force from the actuator is efficiently transmitted to the lens holder.

  The position where the actuator applies the driving force to the lens holder may be set between the shaft and the position where the biasing member applies the biasing force to the lens holder. In this case, the distance between the shaft and the position where the biasing member applies the biasing force to the lens holder is longer than the distance between the position where the actuator applies the driving force to the lens holder and the shaft. For this reason, the urging force provided by the urging member, which is required to make the contact state between the lens holder and the actuator a desired state, can be reduced. Therefore, the load acting on the shaft is reduced, and the friction between the shaft and the lens holder is reduced. As a result, less driving force is required to move the lens holder, power consumption for driving the lens holder can be reduced, and the life of the lens driving device can be extended.

  The housing further includes a lens holder, a shaft, an actuator, and a biasing member. The shaft and the actuator are disposed at the first corner of the housing, and the biasing member is adjacent to the first corner of the housing. You may arrange | position in the 2nd corner | angular part which fits. In this case, since the shaft, the actuator, and the urging member are arranged at the corner of the housing that becomes a dead space, the lens driving device can be easily downsized.

  The urging member has a ball member that contacts the lens holder, and a retainer that rotatably supports the ball member, and the retainer includes a base portion and a support portion that supports the ball member. The biasing force applied to the lens holder may be generated by the support portion being bent with respect to the base portion. In this case, the structure of the urging member that abuts on the lens holder and applies the urging force can be realized easily and at low cost. Further, since the ball member that contacts the lens holder is rotatably supported by the retainer, the friction generated between the ball member and the lens holder is extremely small. Therefore, it is possible to prevent the ball member from resisting movement of the lens holder in the optical axis direction.

  The support portion includes a pair of first pieces arranged with an interval shorter than the diameter of the ball member, and a second piece arranged so as to sandwich the ball member between the pair of first pieces. May be included. In this case, the structure of the retainer that rotatably supports the ball member can be realized simply and at low cost.

  ADVANTAGE OF THE INVENTION According to this invention, the lens drive device which can transmit a driving force from an actuator to a lens holder efficiently can be provided.

It is a perspective view which shows the lens drive device which concerns on this embodiment. It is a perspective view which shows the lens drive device which concerns on this embodiment. It is a top view which shows the lens drive device which concerns on this embodiment. It is a disassembled perspective view which shows the lens drive device which concerns on this embodiment. It is a figure which shows the relationship between a lens holder, a shaft, a piezoelectric actuator, and a biasing member. It is a perspective view which shows the contact state of a piezoelectric actuator and a board | substrate. It is a schematic diagram which shows the mode at the time of the drive of a piezoelectric actuator.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description, the same reference numerals are used for the same elements or elements having the same function, and redundant description is omitted.

  1 and 2 are perspective views showing the lens driving device according to the present embodiment. FIG. 3 is a plan view showing the lens driving device according to the present embodiment. FIG. 4 is an exploded perspective view showing the lens driving device according to the present embodiment. 2 and 3, the lens driving device 1 is shown in a state in which a cover 20 described later is removed.

  As shown in FIGS. 1 to 4, the lens driving device 1 includes a base 10, a cover 20, a lens holder 30, and a piezoelectric actuator unit and an urging member described later. The lens driving device 1 is a device that drives a camera lens mounted on, for example, a mobile phone. The lens driving device 1 is set to have a planar shape of, for example, 8.5 mm × 8.5 mm. In the present embodiment, the base 10 and the cover 20 function as a housing.

  The base 10 includes a bottom portion 11 in which a perfect circular opening 11 a is formed, and a side wall portion 13 erected from the bottom portion 11. The base 10 (bottom part 11) has a substantially rectangular shape in plan view. The side wall part 13 is provided over the four sides of the bottom part 11 and is formed integrally with the bottom part 11. The side wall portion 13 has an inner peripheral surface that is curved along the shape of the opening 11a. The bottom part 11 and the side wall part 13 define a space for accommodating the lens holder 30. The base 10 is formed of, for example, a liquid crystal polymer containing a filler such as glass fiber or inorganic material. The substantially rectangular shape includes not only a shape having a right angle but also a shape having a chamfered corner.

  The side wall portion 13 is provided with a plurality of engaging protrusions 13a for attaching the cover 20. A shaft 15 is disposed at the corner 10 a of the base 10. In the corner portion 10a of the base 10, a space is formed so that a part of the side wall portion 13 is cut out, and the shaft 15 is disposed in the space. One end of the shaft 15 is supported by the bottom portion 11, and the other end is supported by a portion of the side wall portion 13 that faces the bottom portion 11. The shaft 15 is spanned between the bottom portion 11 and the side wall portion 13. The shaft 15 has a perfect circular cross section and is made of, for example, stainless steel. The axial direction of the shaft 15 is set parallel to the optical axis direction OA of the lens.

  The cover 20 has a hollow, substantially rectangular parallelepiped shape with one surface opened. The cover 20 includes a surface portion 21 that faces the bottom portion 11 and side surface portions 23 that respectively extend from the four sides of the surface portion. In the surface portion 21, a perfect circular opening 21a is formed at a position facing the opening 11a. An opening 23a is formed in the side surface portion 23 at a position corresponding to the engagement protrusion 13a. The cover 20 is attached to the base 10 by engaging the engaging protrusions 13a into the openings 23a. The cover 20 is made of, for example, SPCC (cold rolled steel).

  The lens holder 30 has a cylindrical body portion 31 and is disposed in an accommodation space defined by the bottom portion 11 and the side wall portion 13. The trunk | drum 31 is exhibiting the cross-sectional perfect circle shape. A lens barrel LB containing a lens is attached to the inside of the body portion 31. The lens holder 30 holds the lens when the lens barrel LB is attached. The lens held in the lens barrel LB is exposed through the opening 11a and the opening 21a. The lens holder 30 is formed of, for example, a liquid crystal polymer containing carbon fiber or nylon.

  A shaft support portion 33 that supports the shaft 15 is provided on the outer surface of the body portion 31 so as to project outward from the body portion 31. The trunk portion 31 and the shaft support portion 33 are integrally formed. A through hole 33 a through which the shaft 15 is inserted is formed in the shaft support portion 33. The cross-sectional shape of the through hole 33 a is a true circle corresponding to the cross-sectional shape of the shaft 15. The lens holder 30 is supported so as to be movable in the axial direction of the shaft 15 (the optical axis direction OA of the lens) and swingable around the shaft 15 in a state where the shaft 15 is inserted into the through hole 33a.

  The lens holder 30 has a substrate 37 on which a friction portion 51 of a piezoelectric actuator 50 described later comes into contact. The substrate 37 is fixed to a substrate support portion 39 provided on the outer surface of the body portion 31 in the vicinity of the shaft support portion 33. Thereby, the substrate 37 substantially functions as a side surface of the lens holder 30. The substrate 37 is made of, for example, SiC or zirconia. The substrate 37 may be formed integrally with the lens holder 30.

  The piezoelectric actuator unit includes a piezoelectric actuator 50 and a flexible substrate 60 as shown in FIG.

  The piezoelectric actuator 50 is a so-called laminated piezoelectric actuator, is disposed close to the shaft 15, and is positioned at the corner 10 a of the base 10 (bottom 11). The piezoelectric actuator 50 has a plurality (four in this embodiment) of active portions A1 to A4 that expand and contract in accordance with the applied voltage value. On one surface side of the piezoelectric actuator 50, a plurality (two in this embodiment) of friction portions 51 are arranged along the arrangement direction of the active portions A1 to A4.

  On the other surface side of the piezoelectric actuator 50, a plurality of (four in this embodiment) external electrodes 52 are provided corresponding to positions (node points) where expansion and contraction does not occur. Each external electrode 52 extends from the node point toward the end of the piezoelectric actuator 50. That is, one end of each external electrode 52 is located at the node point, and the other end is located away from the node point. The other end of each external electrode 52 is connected to the flexible substrate 60.

  As shown in FIG. 6, each friction portion 51 has a substantially semi-cylindrical shape, and is disposed apart from the optical axis direction OA of the lens and extends in a direction perpendicular to the optical axis direction OA. Yes. The friction part 51 comes into contact indirectly with the side surface of the lens holder 30 by making contact with the substrate 37.

  The piezoelectric actuator 50 has two resonance modes when driven. Specifically, the piezoelectric actuator 50 includes a longitudinal vibration mode (first vibration mode) that vibrates in the longitudinal direction of the piezoelectric actuator 50 and a bending vibration mode (second vibration mode) in the thickness direction of the piezoelectric actuator 50. Vibrates due to the superposition of

  When the active portion A1 including the first internal electrode, the ground internal electrode, and the piezoelectric layer and the active portion A4 including the fourth internal electrode, the ground internal electrode, and the piezoelectric layer are driven, FIG. As shown in FIG. 5A, one friction part 51 comes into contact with the substrate 37, and a frictional force is generated between the one friction part 51 and the substrate 37. The substrate 37 moves in the direction of the arrow in FIG. 7A due to the frictional force generated between one friction part 51 and the substrate 37.

  When the active part A2 composed of the second internal electrode, the ground internal electrode and the piezoelectric layer and the active part A3 composed of the third internal electrode, the ground internal electrode and the piezoelectric layer are driven, FIG. As shown in (b), the other friction portion 51 comes into contact with the substrate 37, and a frictional force is generated between the other friction portion 51 and the substrate 37. The substrate 37 moves in the direction of the arrow in FIG. 7B due to the frictional force generated between the other friction part 51 and the substrate 37.

  When the piezoelectric actuator 50 is driven by applying a voltage whose phase is shifted by 90 degrees to the external electrode 52 connected to the first internal electrode and the external electrode 52 connected to the second internal electrode, An elliptical motion whose phase is shifted by 180 degrees occurs, and a frictional force acts alternately between the substrate 37 and the substrate 37 (lens holder 30) moves. That is, the friction part 51 of the piezoelectric actuator 50 drives the lens holder 30 along the optical axis direction OA of the lens.

  In the example shown in FIG. 7, the length of the boundary portion of the piezoelectric element and the arrangement direction of the piezoelectric actuator 50 (the optical axis direction OA of the lens) is about 1/6 L from the end of the piezoelectric actuator 50. There are three node points N1, N2, and N3 at the inner position. The node point N1 is not displaced in the arrangement direction or thickness direction of the piezoelectric elements, and the node points N2 and N3 are displaced in the arrangement direction of the piezoelectric elements but not in the thickness direction.

  Each external electrode 52 is connected to a corresponding internal electrode at a position corresponding to the central node point N1, that is, at one end. One end portions of the external electrodes 52 are arranged apart from each other at the central node point N1.

  The flexible substrate 60 is a so-called flexible printed circuit (FPC), and has a film-like insulator and a wiring portion arranged on the insulator. The wiring portion includes a wiring connected to each external electrode 52 by soldering or the like. The flexible substrate 60 (insulator) is disposed along one side of the base 10 (side wall portion 13). In the present embodiment, the flexible substrate 60 is disposed so as to cross between the corner portion 10a and the corner portion 10b.

  As shown in FIG. 4, the flexible substrate 60 includes a first portion 65 extending along a direction parallel to the one side, and a second portion 67 extending from the first portion 65 along the optical axis direction OA of the lens. And. The flexible substrate 60 is positioned with respect to the base 10, the lens holder 30, and the like by fixing the second portion 67 to the side wall portion 13 by adhesion or the like. The second portion 67 is pulled out to the outside of the lens driving device 1 through a gap formed between the base 10 and the cover 20. A piezoelectric actuator 50 is mounted on the tip region of the first portion 65 of the flexible substrate 60.

  The tip region of the first portion 65 is formed in a bifurcated shape so as to be separated from each other in the optical axis direction OA of the lens. The tip region of the first portion 65 is located such that the region between the tip portions 65 corresponds to the central node point N <b> 1 of the piezoelectric actuator 50. As a result, the central node point N1 of the piezoelectric actuator 50 is exposed as viewed from the flexible substrate 60 side. Since the tip region of the first portion 65 is formed in a bifurcated shape, the piezoelectric actuator 50 is mechanically connected to the tip region of the first portion 65 at a position away from the central node point N1. Thereby, it can prevent that the flexible substrate 60 inhibits the vibration which the piezoelectric actuator 50 mentioned above.

  A plate member 70 is disposed on the back surface of the surface of the first portion 65 where the piezoelectric actuator 50 is mounted so as to face the back surface. That is, the plate member 70 is arranged so as to sandwich the flexible substrate 60 (the tip region of the first portion 65) with the piezoelectric actuator 50. The plate member 70 is fixed to the base 10 (side wall portion 13) by adhesion or the like. The plate member 70 is made of, for example, ceramic or stainless steel.

  A protrusion 70 a is formed on the surface of the plate member 70 that faces the tip region of the first portion 65, that is, the surface that faces the piezoelectric actuator 50 across the flexible substrate 60. The protruding portion 70a is positioned so as to correspond to the region between the tip regions of the first portion 65, and is exposed when viewed from the flexible substrate 60 side. The protruding portion 70 a has a substantially triangular cross-sectional shape and extends along the width direction of the plate member 70. In a state where the plate member 70 is fixed to the base 10, the protruding portion 70a extends along a direction orthogonal to the optical axis direction OA of the lens.

  The protruding portion 70a of the plate member 70 is fixed to the central node point N1 of the piezoelectric actuator 50 by bonding or the like. As a result, the position of the piezoelectric actuator 50 relative to the base 10 is defined, and the contact state between each friction part 51 and the lens holder 30 (substrate 37) is defined. Since the piezoelectric actuator 50 and the plate member 70 are fixed at the node point N1, the fixing of the piezoelectric actuator 50 and the plate member 70 can be prevented from inhibiting the above-described vibration of the piezoelectric actuator 50.

  As described above, the position where the plate member 70 is bonded in the piezoelectric actuator 50 is preferably a node point where the piezoelectric element does not expand and contract. However, in order to securely bond the piezoelectric actuator 50 and the plate member 70, the position at which the plate member 70 is bonded may extend over a position shifted from the node point.

  The urging member has a ball member 71 and a retainer 73 as shown in FIG. The urging member abuts on the lens holder 30 so as to rotate the lens holder 30 toward the piezoelectric actuator 50 (R direction in the drawing), that is, so that the friction portion 51 and the substrate 37 abut on each other. give. The ball member 71 and the retainer 73 are disposed in the corner portion 10 b adjacent to the corner portion 10 a of the base 10, and are positioned between the side wall portion 13 and the lens holder 30.

  The retainer 73 supports the ball member 71 rotatably. The retainer 73 includes a base portion 75 and a support portion 77. The base portion 75 extends along the inner surface of the side wall portion 13 and is fixed to the side wall portion 13 by bonding or the like. The support portion 77 extends from one end of the base portion 75 so as to have a predetermined angle with respect to the base portion 75, and supports the ball member 71. The support part 77 includes a pair of a first piece 77a and a second piece 77b. The pair of first pieces 77a are juxtaposed along the optical axis direction OA of the lens with an interval shorter than the diameter of the ball member 71. The second piece 77b is disposed so as to sandwich the ball member 71 between the pair of first pieces 77a.

  The ball member 71 is in contact with the lens holder 30 while being supported by the retainer 73. A contact portion 35 that contacts the ball member 71 is provided on the outer surface of the body portion 31 of the lens holder 30 so as to project outward from the body portion 31. The body part 31 and the contact part 35 are formed integrally. The retainer 73 functions as a leaf spring, and generates the urging force F applied to the lens holder 30 when the support portion 77 is bent with respect to the base portion 75.

  In the lens driving device 1, as described above, the shaft 15 and the piezoelectric actuator 50 are disposed at the same corner 10a, and the ball member 71 and the retainer 73 are disposed at the corner 10b adjacent to the corner 10a. . The position at which the piezoelectric actuator 50 applies the driving force to the lens holder 30 is set between the shaft 15 and the position at which the biasing members (the ball member 71 and the retainer 73) apply the biasing force F to the lens holder 30. ing. Therefore, the position at which the urging member (the ball member 71 and the retainer 73) applies the urging force F to the lens holder 30 and the shaft 15 rather than the distance between the position at which the piezoelectric actuator 50 applies the driving force to the lens holder 30 and the shaft 15. The interval is long.

  The ball member 71 is made of, for example, stainless steel. The retainer 73 is made of, for example, stainless steel, and can be formed by press-molding stainless steel.

  The lens driving device 1 further includes a position detection element 80 for detecting the position of the lens of the lens holder 30 in the optical axis direction OA. The position detection element 80 includes a light emitting element (for example, a light emitting diode) and a light receiving element (for example, a photodiode). The position detection element 80 is disposed at a corner portion 10c that is located diagonally to the corner portion 10a of the base 10. An opening 17 is formed in the side wall portion 13 at a position corresponding to the position detection element 80. The position detection element 80 is fixed to the base 10 by adhesion or the like. In the position detection element 80, the light emitted from the light emitting element passes through the opening 17 and enters the reflecting plate 81 fixed to the outer surface of the lens holder 30, and the light reflected by the reflecting plate 81 again passes through the opening 17. The light passes through the light receiving element and is detected.

  The position detection element 80 is mounted on the flexible substrate 83. Like the flexible substrate 60, the flexible substrate 83 is an FPC, and includes a film-like insulator and a wiring portion disposed on the insulator. The wiring portion includes a wiring connected to the terminal electrode of the position detection element 80 by soldering or the like. An output signal of the position detection element 80 (light receiving element) is sent to a control unit (not shown) through the wiring portion of the flexible substrate 83. The control unit obtains the position of the lens in the optical axis direction OA from the output signal of the position detection element 80 based on a known method. The control unit outputs a drive signal for the light emitting element, and this drive signal is input to the light emitting element through the wiring portion of the flexible substrate 83.

  As described above, in the present embodiment, the direction in which the lens holder 30 is rotated toward the piezoelectric actuator 50 with respect to the lens holder 30 from the urging member (the ball member 71 and the retainer 73) (the direction of the arrow R in FIG. 5). ) Is always given an urging force F. For this reason, the contact state between the lens holder 30 (substrate 37) and the piezoelectric actuator 50 (friction part 51) is maintained well. The urging members (the ball member 71 and the retainer 73) are not positioned on the driving force transmission path from the piezoelectric actuator 50 to the lens holder 30. As a result, the driving force from the piezoelectric actuator 50 is efficiently transmitted to the lens holder 30.

  In the present embodiment, the biasing members (the ball member 71 and the retainer 73) apply a biasing force F to the lens holder 30 rather than the distance between the shaft 15 and the position where the piezoelectric actuator 50 applies the driving force to the lens holder 30. Since the distance between the shaft 15 and the shaft 15 is long, the urging force F required to make the contact state between the lens holder 30 and the piezoelectric actuator 50 a desired state is small. Therefore, the load acting on the shaft 15 is reduced, and the friction between the shaft 15 and the lens holder 30 is reduced. As a result, less driving force is required to move the lens holder 30, power consumption for driving the lens holder 30 can be reduced, and the life of the lens driving device 1 can be extended.

  For example, when the biasing member is disposed at a corner portion of the base 10 that is opposite to the corner portion 10b, the shaft 15 is positioned so that the piezoelectric actuator 50 applies a driving force to the lens holder 30, and the biasing member is It will be located between the position where the urging force F is applied to the lens holder 30. The distance between the position where the piezoelectric actuator 50 applies the driving force to the lens holder 30 and the shaft 15 is shorter than the distance between the position where the biasing member applies the biasing force F to the lens holder 30 and the shaft 15. For this reason, the urging force required for making the contact state between the lens holder 30 and the piezoelectric actuator 50 a desired state must be set to a value larger than the urging force F described above, and acts on the shaft 15. Will increase the load.

  In the present embodiment, the lens holder 30, the shaft 15, the piezoelectric actuator 50, and the urging member (the ball member 71 and the retainer 73) are accommodated in a housing constituted by the base 10 and the cover 20. The shaft 15 and the piezoelectric actuator 50 are disposed at the corner 10a of the base 10, and the ball member 71 and the retainer 73 are disposed at the corner 10b adjacent to the corner 10a. Thereby, since the shaft 15, the piezoelectric actuator 50, the ball member 71, and the retainer 73 are disposed in the corner portions 10a and 10b of the housing (base 10) that becomes a dead space, the lens driving device 1 can be easily reduced in size. Can be planned.

  In the present embodiment, the ball member 71 and the retainer 73 constitute an urging member, and the retainer 73 rotatably supports the ball member 71 that abuts on the lens holder 30. The retainer 73 includes a base portion 75 and a support portion 77 that supports the ball member 71, and the biasing force F applied to the lens holder 30 is generated by the support portion 77 being bent with respect to the base portion 75. . Thereby, the structure of the urging member that applies the urging force F described above can be realized simply and at low cost. In addition, since the ball member 71 in contact with the lens holder 30 is rotatably supported by the retainer 73, the friction generated between the ball member 71 and the lens holder 30 is extremely small. Accordingly, it is possible to prevent the ball member 71 from resisting movement of the lens holder 30 in the optical axis direction OA.

  In the present embodiment, the support portion 77 includes a pair of first pieces 77a and a second piece 77b, and the pair of first pieces 77a and the second piece 77b sandwich the ball member 71. Thereby, the structure of the retainer 73 which supports the ball member 71 rotatably is realizable at low cost.

  The preferred embodiments of the present invention have been described above. However, the present invention is not necessarily limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention.

  The configuration of the urging member that abuts on the lens holder 30 and applies the urging force F is not limited to the configuration using the retainer 73 that functions as the plate spring described above, and a member that can be elastically deformed is used in addition to the coil spring. The configuration may be acceptable.

  The urging member (the ball member 71 and the retainer 73) may be disposed in the corner portion 10c. However, in this case, the distance between the position where the urging member applies the urging force F to the lens holder 30 and the shaft 15 becomes too large, so that a warp or the like occurs between the shaft 15 and the lens holder 30, and the lens holder There is a risk that a load is generated for 30 movements.

  The present invention can be used for a lens driving device that drives a camera lens mounted on a mobile phone or the like.

  DESCRIPTION OF SYMBOLS 1 ... Lens drive device, 10 ... Base, 10a, 10b ... Corner | angular part, 15 ... Shaft, 20 ... Cover, 30 ... Lens holder, 50 ... Piezoelectric actuator, 71 ... Ball member, 73 ... Retainer, 75 ... Base, 77 ... Support part, 77a ... first piece, 77b ... second piece, F ... biasing force, OA ... optical axis direction of the lens.

Claims (5)

A lens holder for holding the lens;
A shaft that supports the lens holder so as to be movable in the optical axis direction of the lens and swingable around the axis;
An actuator for applying a driving force to the lens holder so as to move the lens holder in the optical axis direction;
An urging member that abuts against the lens holder and applies an urging force so as to rotate the lens holder toward the actuator side.   The position at which the actuator applies a driving force to the lens holder is set between the shaft and a position at which the biasing member applies a biasing force to the lens holder. The lens driving device described. A housing that houses the lens holder, the shaft, the actuator, and the biasing member;
The shaft and the actuator are disposed at a first corner of the housing,
The lens driving device according to claim 2, wherein the biasing member is disposed at a second corner portion adjacent to the first corner portion of the housing. The biasing member includes a ball member that abuts on the lens holder, and a retainer that rotatably supports the ball member,
The retainer includes a base portion and a support portion that supports the ball member, and the biasing force that is applied to the lens holder is generated by the support portion being bent with respect to the base portion. The lens drive device as described in any one of Claims 1-3.   The support portion is a second portion disposed so as to sandwich the ball member between a pair of first pieces disposed at a distance shorter than the diameter of the ball member and the pair of first pieces. The lens driving device according to claim 4, further comprising: a piece.

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