Lens driving device and camera module

Abstract

To provide a lens driving device which can suppress adverse influence due to abrasion powder generated in a part where a piezoelectric driving part and a lens holding member are in contact with each other.SOLUTION: A lens driving device 101 includes: a lens holding member 2; a piezoelectric driving part PD for moving the lens holding member 2 in the direction of an optical axial; and an energization member 6 for energizing the piezoelectric driving part PD toward the lens holding member 2. The lens holding member 2 is driven by activation of a piezoelectric element 8. The lens holding member 2 is provided with a reception member 11 facing the piezoelectric driving part PD to be in contact with the piezoelectric driving part PD. The piezoelectric driving part PD has a contact member 9 in contact with the reception member 11 in a surface of the piezoelectric element 8 on the lens holding member 2 side. The contact member 9 is formed of a magnetic material. The reception member 11 is a magnet.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a lens driving device and a camera module mounted on, for example, a mobile device with a camera. [Background technology]

[0002] Conventionally, a lens driving unit (lens driving device) is known that can move a lens carrier (lens holding member) in the optical axis direction relative to a module base (base member) by friction drive utilizing the bending motion of a piezoelectric driving unit that includes a piezoelectric element (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-097216 A Summary of the Invention [Problem to be solved by the invention]

[0004] The above-mentioned lens driving unit moves the lens carrier in the optical axis direction by bringing a contact portion of the piezoelectric driving portion into contact with an axial guide portion fixed to the lens carrier.

[0005] However, in the above-described configuration, frictional contact between the contact portion and the shaft-shaped guide portion generates wear powder, which may adversely affect the lens driving device or the camera module.

[0006] It is therefore desirable to be able to suppress the adverse effects of wear particles generated at the contact portion between the piezoelectric drive portion and the lens holding member. [Means for solving the problem]

[0007] A lens driving device according to an embodiment of the present invention is configured to have a fixed side member, a lens holding member capable of holding a lens body, a guide mechanism for guiding the lens holding member so that it can move in the optical axis direction relative to the fixed side member, a piezoelectric element extending in a direction intersecting the optical axis direction, a piezoelectric driving unit for moving the lens holding member in the optical axis direction, and a biasing member for biasing the piezoelectric driving unit toward the lens holding member, and the lens holding member is driven by movement of the piezoelectric element, wherein the lens holding member is provided with a receiving member that faces the piezoelectric driving unit so as to come into contact with the piezoelectric driving unit and extends in a direction intersecting the extension direction of the piezoelectric element, the piezoelectric driving unit has a contact member that contacts the receiving member on the surface of the piezoelectric element facing the lens holding member, and both the receiving member and the contact member are made of a magnetic material, and at least one of the receiving member and the contact member is a magnet.

[0008] Also, a camera module according to an embodiment of the present invention is a camera module comprising: a fixed-side member; a lens holding member capable of holding a lens body; a guide mechanism for movably guiding the lens holding member in an optical axis direction relative to the fixed-side member; a lens driving device configured to have a piezoelectric element extending in a direction intersecting the optical axis direction, the lens holding member being moved in the optical axis direction by movement of the piezoelectric element; and a biasing member for biasing the piezoelectric driving unit toward the lens holding member; an imaging element facing the lens body; and a control device for driving the piezoelectric driving unit to move the lens holding member in the optical axis direction, The member is provided with a receiving member that faces the piezoelectric driving unit and extends in a direction intersecting the extension direction of the piezoelectric element so as to come into contact with the piezoelectric driving unit, and the piezoelectric driving unit has a contact member that contacts the receiving member on the surface of the piezoelectric element facing the lens holding member, and the control device is configured to be able to switch the operating mode of the lens driving device between a normal mode and a cleaning mode, and a first contact range, which is the area on the surface of the receiving member that the contact member can contact when the normal mode is selected, is smaller than a second contact range, which is the area on the surface of the receiving member that the contact member can contact when the cleaning mode is selected. Effect of the Invention

[0009] The above-described configuration can suppress adverse effects caused by wear particles generated between the piezoelectric drive unit and the lens holding member. [Brief description of the drawings]

[0010] [Figure 1A] FIG. 2 is a perspective view of a lens driving device. [Figure 1B] FIG. 2 is a perspective view of the lens driving device with a cover member removed. [Diagram 2] FIG. 2 is an exploded perspective view of the lens driving device. [Figure 3A] 13 is a top view of the lens holding member and the base member with the link mechanism attached. FIG. [Figure 3B] 13 is a left side view of the lens holding member and the base member with the link mechanism attached. FIG. [Figure 3C] FIG. 13 is a perspective view of the base member with only the second link member attached. [Figure 4A] FIG. 4 is a perspective view of the lens holding member with the link mechanism attached thereto. [Figure 4B] 13 is a left side view of the lens holding member with the link mechanism attached thereto. FIG. [Figure 4C] 13 is a left side view of the lens holding member with the link mechanism attached thereto. FIG. [Figure 5A] 13 is a front view of the link mechanism and the lens holding member when the lens holding member is in the lowest position. FIG. [Figure 5B] 11 is a front view of the link mechanism and the lens holding member when the lens holding member is in the uppermost position. FIG. [Figure 6A] 4 is a perspective view of the lens driving device (excluding the cover member) when the lens holding member is in the lowest position. FIG. [Figure 6B] 4 is a perspective view of the lens driving device (excluding the cover member) when the lens holding member is in the uppermost position. FIG. [Figure 7A] FIG. [Figure 7B] FIG. 2 is a perspective view of a base member to which a ball is attached. [Figure 8A] 2 is a perspective view of a base member to which a lens holding member and a ball are attached. FIG. [Figure 8B] FIG. 4 is a perspective view of a portion of the base member. [Figure 9A] 2 is a perspective view of a lens holding member attached to a base member. FIG. [Figure 9B] FIG. 4 is a perspective view of a portion of the lens holding member. [Figure 10A] FIG. 2 is a perspective view of a lens holding member. [Figure 10B] FIG. 2 is a perspective view of a lens holding member to which a ball is attached. [Figure 11A] FIG. 2 is a perspective view of the lens driving device with a cover member removed. [Figure 11B] FIG. 2 is a perspective view of a portion of the lens driving device with a cover member removed. [Figure 12A] FIG. [Figure 12B] FIG. [Figure 13A] FIG. [Figure 13B] FIG. [Figure 13C] FIG. [Figure 13D] FIG. [Figure 14A] FIG. 13 is a perspective view of a biasing member having a piezoelectric drive attached thereto. [Figure 14B] FIG. 13 is a front view of a biasing member having a piezoelectric drive portion attached thereto. [Figure 14C] FIG. 13 is a top view of a biasing member with a piezoelectric drive attached thereto. [Figure 14D] FIG. 13 is a left side view of the biasing member with the piezoelectric drive portion attached. [Figure 15A] FIG. 13 is a front view of a portion of a biasing member having a piezoelectric drive portion attached via an adhesive. [Figure 15B]FIG. 13 is a left side view of the biasing member to which the piezoelectric driving portion is attached via an adhesive. [Figure 16A] FIG. 2 is a perspective view of a biasing member attached to a base member. [Figure 16B] FIG. 13 is a top view of a portion of a biasing member attached to a base member. [Figure 17] FIG. 2 is a block diagram showing a configuration example of a camera module. [Figure 18A1] FIG. [Figure 18A2] FIG. 4 is a left side view of the piezoelectric driving portion and the receiving member. [Figure 18B1] 13 is a front view of another configuration example of the receiving member. FIG. [Figure 18B2] FIG. 18B2 is a left side view of the piezoelectric driver and the receiving member of FIG. [Figure 19] 13 is a flowchart showing an example of the flow of a determination process. [Figure 20A] FIG. 4 is a left side view of the piezoelectric driving portion and the receiving member. [Figure 20B] FIG. 4 is a left side view of the piezoelectric driving portion and the receiving member. [Figure 20C] FIG. 4 is a left side view of the piezoelectric driving portion and the receiving member. [Figure 20D] FIG. 4 is a left side view of the piezoelectric driving portion and the receiving member. [Figure 20E] FIG. 4 is a left side view of the piezoelectric driving portion and the receiving member. [Figure 21A] FIG. [Figure 21B] FIG. [Figure 21C] FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] A lens driving device 101 according to an embodiment of the present invention will be described below with reference to the drawings. Fig. 1A and Fig. 1B are perspective views of the lens driving device 101. Specifically, Fig. 1A is an overall perspective view of the lens driving device 101, and Fig. 1B is a perspective view of the lens driving device 101 with a cover member 1 removed. Fig. 2 is an exploded perspective view of the lens driving device 101.

[0012] X1 in FIG. 1A represents one direction of the X axis constituting the three-dimensional orthogonal coordinate system, and X2 represents the other direction of the X axis. Y1 represents one direction of the Y axis constituting the three-dimensional orthogonal coordinate system, and Y2 represents the other direction of the Y axis. Similarly, Z1 represents one direction of the Z axis constituting the three-dimensional orthogonal coordinate system, and Z2 represents the other direction of the Z axis. In this embodiment, the X1 side of the lens driving device 101 corresponds to the front side (front side) of the lens driving device 101, and the X2 side of the lens driving device 101 corresponds to the rear side (rear side) of the lens driving device 101. The Y1 side of the lens driving device 101 corresponds to the left side of the lens driving device 101, and the Y2 side of the lens driving device 101 corresponds to the right side of the lens driving device 101. The Z1 side of the lens driving device 101 corresponds to the upper side of the lens driving device 101, and the Z2 side of the lens driving device 101 corresponds to the lower side of the lens driving device 101. The same applies to the other figures.

[0013] As shown in Fig. 2, the lens driving device 101 includes a fixed member FB and a movable member MB. The fixed member FB includes a cover member 1 and a base member 7. The movable member MB includes a lens holding member 2 and a link mechanism LM. The movable member MB is configured to be guided in the optical axis direction by a guide mechanism GM. The optical axis direction includes the direction of the optical axis JD related to the lens body and a direction parallel to the optical axis JD. The movable member MB is also configured to be moved in the optical axis direction by a piezoelectric driving unit PD.

[0014] The cover member 1 is configured to cover the movable member MB. In this embodiment, the cover member 1 is made by performing punching, drawing, and the like on a metal plate. However, the cover member 1 may be formed of other materials such as synthetic resin. Specifically, as shown in FIG. 1A, the cover member 1 has a rectangular cylindrical outer wall portion 1A and a flat rectangular ring-shaped ceiling portion 1B provided so as to be continuous with the upper end (the end on the Z1 side) of the outer wall portion 1A. A circular opening 1K is formed in the center of the ceiling portion 1B. The cover member 1 has a box-shaped outer shape that defines the storage portion 1S, and is configured to store the movable member MB in the storage portion 1S. The cover member 1 is also bonded to the base member 7 by an adhesive, and together with the base member 7, forms a housing HS.

[0015] The lens holding member 2 is configured so that a lens body (not shown) can be held by the cylindrical portion 2C. In this embodiment, the lens holding member 2 is produced by injection molding a synthetic resin such as liquid crystal polymer (LCP). The lens body is, for example, a cylindrical lens barrel equipped with at least one lens.

[0016] The link mechanism LM is an example of a regulating mechanism. The regulating mechanism is a mechanism that is disposed between the lens holding member 2 and the fixed-side member FB, and is configured to suppress a change in posture when the lens holding member 2 moves in the optical axis direction. The change in posture of the lens holding member 2 includes, for example, tilting of the optical axis JD with respect to the Z-axis direction. In this embodiment, the link mechanism LM includes a first link member 3 and a second link member 4, and is disposed between the lens holding member 2 and a base member 7 as the fixed-side member FB, and is configured to suppress a change in posture when the lens holding member 2 moves in the optical axis direction.

[0017] The piezoelectric driving unit PD is configured to be able to move the lens holding member 2 along the optical axis direction. In this embodiment, the piezoelectric driving unit PD is an example of a friction driving unit that utilizes the driving system disclosed in U.S. Patent No. 7,786,648, and includes a piezoelectric element 8, a contact member 9, and a circuit board 10.

[0018] The piezoelectric element 8 is configured to realize bending vibration in response to the applied voltage. In this embodiment, the piezoelectric element 8 extends in the Y-axis direction perpendicular to the optical axis direction (perpendicular to the optical axis JD) and is configured to realize bending vibration having two nodes. Specifically, the piezoelectric element 8 has a two-layer structure consisting of a first layer that realizes a first bending vibration on the XY plane and a second layer that realizes a second bending vibration on the YZ plane. The piezoelectric driving unit PD applies a voltage to the piezoelectric element constituting the first layer and a voltage to the piezoelectric element constituting the second layer separately at appropriate timing, so that the locus drawn by the midpoint of the piezoelectric element 8 becomes a circular orbit centered on the rotation axis 8X. In the example shown in FIG. 2, the rotation axis 8X is parallel to the Y-axis. The piezoelectric driving unit PD applies a voltage at appropriate timing, so that the movement direction (rotation direction) of the midpoint following the circular orbit can be switched between clockwise and counterclockwise as viewed from the Y1 side. The lens holding member 2 is moved upward (Z1 direction) when the rotation direction of the midpoint of the piezoelectric element 8 is clockwise, and is moved downward (Z2 direction) when the rotation direction of the midpoint of the piezoelectric element 8 is counterclockwise. The midpoint of the piezoelectric element 8 is a point where the amplitude of the first bending vibration is maximum (a point corresponding to the antinode of the first bending vibration) and a point where the amplitude of the second bending vibration is maximum (a point corresponding to the antinode of the second bending vibration). In this way, the piezoelectric element 8 in this embodiment is configured to realize a vibration (circular motion) in which the midpoint draws a circle. Note that the circle (circular orbit) drawn by the midpoint of the piezoelectric element 8 does not have to be a perfect circle (true circle), but may be approximately circular.

[0019] The contact member 9 is attached to the piezoelectric element 8 and configured to come into contact with the lens holding member 2. In this embodiment, the contact member 9 is bonded to the inner surface of the piezoelectric element 8 by an adhesive so as to cover the entire inner surface (the side facing the optical axis JD) of the piezoelectric element 8. The contact member 9 is formed of a magnetic material. The magnetic material is, for example, metal, ceramics, rubber, synthetic resin, or the like. The contact member 9 may be a magnet. The contact member 9 is configured to perform bending vibration in response to the bending vibration of the piezoelectric element 8. In this embodiment, the contact member 9 is a friction plate made of stainless steel. The contact member 9 extends in the Y-axis direction, which is the same as the extension direction of the piezoelectric element 8. The contact member 9 is configured so that the center part in the extension direction comes into contact with the receiving member 11 attached to the lens holding member 2. Specifically, the contact member 9 is configured so as to come into contact with the receiving member 11 at a point where the amplitude of the bending vibration is maximum (the antinode of the bending vibration). The receiving member 11 is formed of a magnetic material. The magnetic material is, for example, metal, ceramic, rubber, or synthetic resin. In this embodiment, the receiving member 11 is a metal magnet bipolarly magnetized in the optical axis direction. The purpose is to prevent the wear powder generated by the contact between the contact member 9 and the receiving member 11 from dropping from the contact portion by attracting the wear powder to the surface of the receiving member 11 by magnetic force. Specifically, the receiving member 11 is a cylindrical pin extending in the optical axis direction. However, the receiving member 11 may be a member having a shape other than a cylindrical shape, such as a semi-cylindrical or elliptical cylindrical shape, as long as point contact is realized between the contact member 9 and the receiving member 11. The reason for contacting the metal contact member 9 with the metal receiving member 11 is to prevent wear of the lens holding member 2 caused by contact between the synthetic resin lens holding member 2 and the metal contact member 9 that is significantly harder (higher wear resistance) than the lens holding member 2. Further, even if the contact member 9 and the receiving member 11 are made of magnets, the wear powder generated by the lens holding member 2, which is a non-magnetic member, falls without being attracted to the magnets.

[0020] In this embodiment, the receiving member 11 is made of stainless steel and is configured to have a surface hardness higher than that of the contact member 9. This is because the higher the surface hardness, the less likely wear powder is generated. Also, this is to prevent smooth bending vibration of the contact member 9 from being hindered. That is, it is desirable for the contact member 9 to have a relatively low surface hardness so that bending vibration is performed smoothly. However, as long as excessive generation of wear powder originating from each of the contact member 9 and the receiving member 11 can be suppressed, the receiving member 11 may be configured to have a surface hardness substantially the same as that of the contact member 9, or may be configured to have a surface hardness lower than that of the contact member 9. Also, the receiving member 11 may be subjected to a nitriding treatment (surface hardening treatment) such as a salt bath soft nitriding treatment.

[0021] It should be noted that, as long as contact between the contact member 9 and the receiving member 11 can be obtained, the length of the contact member 9 in the Y-axis direction does not have to be the same as that of the piezoelectric element 8.

[0022] The circuit board 10 is a board including a conductive pattern, and is configured to electrically connect an external control device having a voltage application function to the piezoelectric element 8. In this embodiment, the circuit board 10 is a flexible printed circuit board having flexibility, and is configured to be able to apply a voltage to the piezoelectric element 8. The piezoelectric element 8 is bonded to the inner surface of the circuit board 10 (the side facing the optical axis JD) by an anisotropic conductive adhesive. The piezoelectric element 8 may be bonded to the inner surface of the circuit board 10 by an anisotropic conductive adhesive film.

[0023] The piezoelectric driver PD is configured to be biased inward (toward the optical axis JD) by a biasing member 6 fixed to the base member 7, and pressed against the lens holding member 2. In this embodiment, the biasing member 6 is formed of a metal plate, and configured to come into contact with the outer surface (the side farther from the optical axis JD) of the piezoelectric element 8 via the circuit board 10 at portions corresponding to two nodes formed during bending vibration of the piezoelectric element 8. The biasing member 6 and the piezoelectric driver PD are joined together by, for example, an adhesive.

[0024] The guide mechanism GM is configured to guide the lens holding member 2 movably in the optical axis direction relative to the fixed member FB. In this embodiment, the guide mechanism GM includes a movable groove 2G formed in the columnar portion 2B of the lens holding member 2, a fixed groove 7G formed in the columnar portion 7B of the base member 7, and a ball 5 sandwiched between the movable groove 2G and the fixed groove 7G. The columnar portion 2B of the lens holding member 2 includes a left columnar portion 2BL and a right columnar portion 2BR, and the movable groove portion 2G includes a left movable groove portion 2GL formed in the left columnar portion 2BL and a right movable groove portion 2GR formed in the right columnar portion 2BR.

[0025] Specifically, the guide mechanism GM has two guide parts (a right guide part GMR and a left guide part GML) that are arranged to face each other with a receiving member 11 attached to the lens holding member 2 therebetween.

[0026] The right guide part GMR has a right movable groove part 2GR formed in the right column part 2BR of the lens holding member 2, a right fixed groove part 7GR formed in the right column part 7BR of the base member 7, and a right ball 5R arranged between the right movable groove part 2GR and the right fixed groove part 7GR. The right ball 5R includes an upper right ball 5RU and a lower right ball 5RD.

[0027] The left guide portion GML has a left movable groove portion 2GL formed in the left columnar portion 2BL of the lens holding member 2, a left fixed groove portion 7GL formed in the left columnar portion 7BL of the base member 7, and a left ball 5L arranged between the left movable groove portion 2GL and the left fixed groove portion 7GL. The left ball 5L includes an upper left ball 5LU and a lower left ball 5LD.

[0028] The base member 7 is manufactured by injection molding using a synthetic resin such as a liquid crystal polymer. In this embodiment, as shown in FIG. 2, the base member 7 has an approximately rectangular plate-like outer shape, and a circular opening 7K is formed in the center. In addition, two rectangular convex columnar portions 7B and one rectangular convex wall portion 7W are provided on the surface (upper surface) of the base member 7 on the subject side (Z1 side). In addition, a clamping portion 7C protruding upward is formed at two corners on the front side of the base member 7, and a third pivot support portion 7H protruding upward is formed at two corners on the rear side of the base member 7. The clamping portion 7C is a portion configured to be able to clamp the biasing member 6, and includes a left clamping portion 7CL and a right clamping portion 7CR. The third pivot support portion 7H is a portion configured to be able to support the third shaft portion 3S of the first link member 3, and includes a left third pivot support portion 7HL and a right third pivot support portion 7HR. 3C, fourth pivotal support portions 7J are formed at the left front corner and the left rear corner of the base member 7. The fourth pivotal support portion 7J is a portion configured such that at least the right side (Y2 side) is open so as to be able to support the fourth shaft portion 4S of the second link member 4, and includes a front fourth pivotal support portion 7JF and a rear fourth pivotal support portion 7JB.

[0029] A sensor 12 is attached to the wall 7W of the base member 7. Specifically, the sensor 12 mounted on a sensor circuit board 14 is attached to the rear surface (X2 side surface) of the wall 7W so as to face a magnet 13 attached to the lens holding member 2. The sensor 12 is connected to an external control device CTR (see FIG. 17) via the sensor circuit board 14 (see FIG. 11B).

[0030] The sensor 12 is configured to detect the position of the movable member MB. In this embodiment, the sensor 12 is configured with a Hall element, and is configured to measure an output voltage that changes according to the magnitude of the magnetic field caused by the magnet 13 that the sensor 12 receives, and detect the position of the movable member MB (lens holding member 2) including the magnet 13. However, the sensor 12 may be configured to detect the position of the movable member MB by using a magnetoresistance element such as a Giant Magneto Resistive effect (GMR) element, a Semiconductor Magneto Resistive (SMR) element, an Anisotropic Magneto Resistive (AMR) element, or a Tunnel Magneto Resistive (TMR) element.

[0031] The lens driving device 101 has an approximately rectangular parallelepiped outer shape and is attached on a substrate (not shown) on which an imaging element (not shown) is mounted. The substrate, the lens driving device 101, a lens body (not shown) attached to the lens holding member 2, and the imaging element mounted on the substrate so as to face the lens body constitute a camera module. The piezoelectric element 8 is connected to an external control device CTR via a circuit board 10. When a voltage is applied to the piezoelectric element 8, the piezoelectric element 8 performs a first bending vibration and a second bending motion, generating a force that moves the lens holding member 2 along the optical axis direction. This force is a frictional force caused by contact between a receiving member 11 attached to the lens holding member 2 and a contact member 9 joined to the piezoelectric element 8.

[0032] The lens driving device 101 utilizes this force to move the lens holding member 2 along the optical axis direction on the Z1 side (subject side) of the imaging element, thereby realizing an automatic focus adjustment function. Specifically, the lens driving device 101 moves the lens holding member 2 in a direction away from the imaging element to enable macro photography, and moves the lens holding member 2 in a direction toward the imaging element to enable infinity photography.

[0033] Next, the link mechanism LM, which is an example of a regulating mechanism, will be described in detail with reference to Figs. 3A to 3C, 4A to 4C, 5A, and 5B. Figs. 3A to 3C are views of the base member 7 with the link mechanism LM attached. Specifically, Fig. 3A is a top view of the lens holding member 2 and the base member 7 with the link mechanism LM attached, Fig. 3B is a left side view of the lens holding member 2 and the base member 7 with the link mechanism LM attached, and Fig. 3C is a perspective view of the base member 7 with only the second link member 4 attached. Note that Figs. 3A to 3C all show the lens holding member 2, which is movable in the optical axis direction, positioned at the lowest position (Z2 side). Figs. 4A to 4C, 5A, and 5B are views of the lens holding member 2 with the link mechanism LM attached. Specifically, Fig. 4A is a perspective view of the lens holding member 2 with the link mechanism LM attached, and Figs. 4B and 4C are left side views of the lens holding member 2 with the link mechanism LM attached. Figs. 5A and 5B are front views of the lens holding member 2 with the link mechanism LM attached. Figs. 4A and 4B show the lens holding member 2 when it is positioned at the lowest side (Z2 side), and Fig. 4C shows the lens holding member 2 when it is positioned at the highest side (Z1 side). Fig. 5A shows the lens holding member 2 when it is positioned at the lowest side (Z2 side), and Fig. 5B shows the lens holding member 2 when it is positioned at the highest side (Z1 side).

[0034] 3A to 3C, 4A to 4C, 5A, and 5B, the link mechanism LM has a first link member 3 and a second link member 4. In this embodiment, the first link member 3 and the second link member 4 are produced by injection molding a synthetic resin such as liquid crystal polymer (LCP).

[0035] The first link member 3 is connected to the lens holding member 2 so as to be rotatable around the first rotation axis RA1, and the second link member 4 is connected to the lens holding member 2 so as to be rotatable around the second rotation axis RA2. The first link member 3 is connected to the base member 7 so as to be rotatable around the third rotation axis RA3, and the second link member 4 is connected to the base member 7 so as to be rotatable around the fourth rotation axis RA4. The first rotation axis RA1 and the third rotation axis RA3 are arranged parallel to each other, and the second rotation axis RA2 and the fourth rotation axis RA4 are arranged parallel to each other. In a plan view seen from the optical axis direction, the first rotation axis RA1 and the third rotation axis RA3 are arranged perpendicular to the second rotation axis RA2 and the fourth rotation axis RA4. Specifically, in a plan view seen from the optical axis direction, the first rotation axis RA1 and the second rotation axis RA2 are disposed so as to be perpendicular to each other at the position of the optical axis JD, and the third rotation axis RA3 and the fourth rotation axis RA4 are disposed so as to be perpendicular to each other at the position of the left rear corner of the base member 7. In addition, the first rotation axis RA1 and the second rotation axis RA2 are each perpendicular to the optical axis direction.

[0036] As shown in Figures 5A, 8A, and 10A, the lens holding member 2 has a pair of first shaft portions 2S (a left-side first shaft portion 2SL and a right-side first shaft portion 2SR) and a pair of second shaft portions 2T (a front-side second shaft portion 2TF and a rear-side second shaft portion 2TB).

[0037] As shown in FIG. 3A, the first link member 3 has a first base 3B formed with a pair of third shafts 3S (left third shaft 3SL and right third shaft 3SR) rotatably supported by the base member 7, and a pair of first arms 3A (left first arm 3AL and right first arm 3AR) connected to the first base 3B and facing each other. A first shaft support 3H (left first shaft support 3HL and right first shaft support 3HR) is formed at the tip of each of the pair of first arms 3A. As shown in FIG. 5A, the left first shaft support 3HL supports the left first shaft 2SL formed in the lens holding member 2, and the right first shaft support 3HR supports the right first shaft 2SR formed in the lens holding member 2. As shown in FIG. 3A, the left third shaft portion 3SL is supported by a left third shaft support portion 7HL formed in the left rear corner of the base member 7, and the right third shaft portion 3SR is supported by a right third shaft support portion 7HR formed in the right rear corner of the base member 7.

[0038] As shown in FIG. 3C, the second link member 4 has a second base 4B formed with a pair of fourth shafts 4S (front side fourth shaft 4SF and rear side fourth shaft 4SB) rotatably supported by the base member 7, and a pair of second arms 4A (front side second arm 4AF and rear side second arm 4AB) connected to the second base 4B and facing each other. A second support portion 4H (front side second support portion 4HF and rear side second support portion 4HB) is formed at the tip of each of the pair of second arms 4A. The front side second support portion 4HF supports the front side second shaft portion 2TF (see FIG. 8A) formed on the lens holding member 2, and the rear side second support portion 4HB supports the rear side second shaft portion 2TB (see FIG. 10A) formed on the lens holding member 2. As shown in FIG. 3C, the front fourth axle portion 4SF is supported by a front fourth axle support portion 7JF formed in the left front corner of the base member 7, and the rear fourth axle portion 4SB is supported by a rear fourth axle support portion 7JB formed in the left rear corner of the base member 7.

[0039] In this way, the lens holding member 2 and the first link member 3 are connected via the first shaft portion 2S and the first support portion 3H, and the lens holding member 2 and the second link member 4 are connected via the second shaft portion 2T and the second support portion 4H.

[0040] In this embodiment, the first shaft support portion 3H has a U-shaped first recess UR1 with an open front side (X1 side) as shown in Fig. 4B. The first shaft portion 2S is located in the first recess UR1 and is configured to form a gap D1 between the inner bottom surface of the first recess UR1 and the first shaft portion 2S.

[0041] 5A, the second shaft support portion 4H has a U-shaped second recess UR2 that is open on the right side (Y2 side). The second shaft portion 2T is located within the second recess UR2 and is configured to form a gap D2 between the inner bottom surface of the second recess UR2 and the second shaft portion 2T.

[0042] The link mechanism LM is configured so that the size of each of the gaps D1 and D2 changes when the lens holding member 2 moves along the optical axis direction. This is to prevent the attitude of the lens holding member 2 from changing when the lens holding member 2 moves along the optical axis direction. In this embodiment, as shown in Figures 4B and 4C, the link mechanism LM is configured so that the size of the gap D1 decreases when the lens holding member 2 moves upward (Z1 direction). Also, as shown in Figures 5A and 5B, the link mechanism LM is configured so that the size of the gap D2 decreases when the lens holding member 2 moves upward (Z1 direction).

[0043] Next, the guide mechanism GM will be described in detail with reference to Figs. 6A, 6B, 7A, 7B, 8A, 8B, 9A, 9B, 10A, and 10B. Figs. 6A and 6B are perspective views of the lens driving device 101 with the cover member 1 removed. Specifically, Fig. 6A shows the state when the lens holding member 2 is located at the lowest side (Z2 side), and Fig. 6B shows the state when the lens holding member 2 is located at the highest side (Z1 side). Figs. 7A and 7B are perspective views of the entire base member 7. Specifically, Fig. 7A shows the state when the ball 5 is not installed in the fixed groove portion 7G formed in the columnar portion 7B of the base member 7, and Fig. 7B shows the state when the ball 5 is installed in the fixed groove portion 7G. Figs. 8A and 8B are perspective views of the base member 7. Specifically, Fig. 8A is a perspective view of the entire base member 7 to which the lens holding member 2 and the ball 5 are attached. FIG. 8B is an enlarged view of an area R1 surrounded by a dashed line shown in FIG. 8A. In FIG. 8B, members other than the base member 7 are omitted from the illustration for clarity. FIGS. 9A and 9B are perspective views of the lens holding member 2. Specifically, FIG. 9A is an overall perspective view of the lens holding member 2 attached to the base member 7. FIG. 9B is an enlarged view of an area R2 surrounded by a dashed line shown in FIG. 9A. In FIG. 9B, members other than the lens holding member 2 are omitted from the illustration for clarity. FIGS. 10A and 10B are overall perspective views of the lens holding member 2. Specifically, FIG. 10A shows a state when a ball 5 is not installed in a movable side groove portion 2G formed in a columnar portion 2B of the lens holding member 2, and FIG. 10B shows a state when a ball 5 is installed in the movable side groove portion 2G.

[0044] As shown in Figures 6A, 6B, 7A, 7B, 8A, 8B, 9A, 9B, 10A, and 10B, the guide mechanism GM includes a right guide part GMR and a left guide part GML arranged to face each other in the left-right direction (Y-axis direction) with the receiving member 11 in between. Specifically, the right guide part GMR has a right movable groove part 2GR (see Figure 10A) provided in the right columnar part 2BR of the lens holding member 2, a right fixed groove part 7GR (see Figure 7A) provided in the base member 7 and facing the right movable groove part 2GR, and a right ball 5R (see Figure 7B) arranged between the right movable groove part 2GR and the right fixed groove part 7GR.

[0045] Specifically, the right fixed groove portion 7GR is divided into two recesses 7V as shown in FIG. 7A. The recess 7V includes an upper right recess 7VRU and a lower right recess 7VRD. The right ball 5R includes an upper right ball 5RU accommodated in the upper right recess 7VRU and a lower right ball 5RD accommodated in the lower right recess 7VRD as shown in FIG. 7B. On the other hand, the right movable groove portion 2GR is not divided into two recesses as shown in FIG. 10A, and extends continuously in the optical axis direction (Z axis direction). With this configuration, the upper right ball 5RU and the lower right ball 5RD are maintained at a predetermined interval without approaching each other even when the lens holding member 2 moves along the optical axis direction. This is because the upper right ball 5RU and the lower right ball 5RD are restricted from moving in the optical axis direction by the upper right recess 7VRU and the lower right recess 7VRD.

[0046] Similarly, the left side guide portion GML has a left movable groove portion 2GL (see Figure 10A) provided on the left side columnar portion 2BL of the lens holding member 2, a left fixed groove portion 7GL (see Figure 7A) provided on the base member 7 and facing the left movable groove portion 2GL, and a left ball 5L (see Figure 7B) arranged between the left movable groove portion 2GL and the left fixed groove portion 7GL.

[0047] Specifically, the left fixed groove 7GL is divided into two recesses 7V as shown in FIG. 8B. The recess 7V includes an upper left recess 7VLU and a lower left recess 7VLD. The left ball 5L includes an upper left ball 5LU accommodated in the upper left recess 7VLU and a lower left ball 5LD accommodated in the lower left recess 7VLD as shown in FIG. 7B. On the other hand, the left movable groove 2GL is not divided into two recesses as shown in FIG. 9B, and extends continuously in the optical axis direction (Z-axis direction). With this configuration, the upper left ball 5LU and the lower left ball 5LD are maintained at a predetermined interval as shown in FIG. 10B without approaching each other even when the lens holding member 2 moves along the optical axis direction. This is because the upper left ball 5LU and the lower left ball 5LD are restricted from moving in the optical axis direction by the upper left recess 7VLU and the lower left recess 7VLD.

[0048] By including the above-mentioned guide mechanism GM, the lens driving device 101 can smoothly move the lens holding member 2 along the optical axis direction. Also, by including the above-mentioned link mechanism LM, the lens driving device 101 can prevent the lens holding member 2 from tilting when the lens holding member 2 moves along the optical axis direction.

[0049] Next, the details of the piezoelectric driving unit PD will be described with reference to Figs. 11A, 11B, 12A, 12B, 13A to 13D, 14A to 14D, 15A, 15B, 16A, and 16B. Figs. 11A and 11B are perspective views of the lens driving device 101 with the cover member 1 removed. Specifically, Fig. 11A is a perspective view of the lens driving device 101 with the piezoelectric driving unit PD and the biasing member 6 further removed. Fig. 11B is an enlarged view of the range R3 surrounded by a dashed line shown in Fig. 11A. Figs. 12A and 12B are perspective views of the piezoelectric driving unit PD. Specifically, Fig. 12A is a perspective view of the entire piezoelectric driving unit PD, and Fig. 12B is an exploded perspective view of the piezoelectric driving unit PD. Figs. 13A to 13D are detailed views of the biasing member 6. Specifically, FIG. 13A is a perspective view of the urging member 6, FIG. 13B is a front view of the urging member 6, FIG. 13C is a top view of the urging member 6, and FIG. 13D is a left side view of the urging member 6. FIGS. 14A to 14D are detailed views of the urging member 6 to which the piezoelectric driving unit PD is attached, and correspond to FIGS. 13A to 13D. Specifically, FIG. 14A is a perspective view of the urging member 6 to which the piezoelectric driving unit PD is attached, and corresponds to FIG. 13A. FIG. 14B is a front view of the urging member 6 to which the piezoelectric driving unit PD is attached, and corresponds to FIG. 13B. FIG. 14C is a top view of the urging member 6 to which the piezoelectric driving unit PD is attached, and corresponds to FIG. 13C. FIG. 14D is a left side view of the urging member 6 to which the piezoelectric driving unit PD is attached, and corresponds to FIG. 13D. 15A and 15B are diagrams of the biasing member 6 to which the piezoelectric driving unit PD is attached via an adhesive AD. Specifically, FIG. 15A is an enlarged view of the area R4 surrounded by the dashed line shown in FIG. 14B. FIG. 15B is a left side view of the biasing member 6 to which the piezoelectric driving unit PD is attached via an adhesive AD, and corresponds to FIG. 13D and FIG. 14D. FIG. 16A and 16B are diagrams of the base member 7 to which the biasing member 6 is attached. Specifically, FIG. 16A is a perspective view of the entire base member 7 to which the biasing member 6 is attached. FIG. 16B is an enlarged top view of the area R5 surrounded by the dashed line shown in FIG. 16A.

[0050] In this embodiment, the biasing member 6 is configured by a leaf spring member. Specifically, as shown in Fig. 13A to Fig. 13D, the biasing member 6 has a fixed portion 6F fixed to the base member 7, a support portion 6S supporting the piezoelectric driving unit PD, and an elastically deformable elastic portion 6E provided between the fixed portion 6F and the support portion 6S.

[0051] Specifically, the fixing portion 6F includes a left fixing portion 6FL and a right fixing portion 6FR, the supporting portion 6S includes a left supporting portion 6SL and a right supporting portion 6SR, and the elastically deforming portion 6E includes a left elastically deforming portion 6EL provided between the left fixing portion 6FL and the left supporting portion 6SL, and a right elastically deforming portion 6ER provided between the right fixing portion 6FR and the right supporting portion 6SR.

[0052] The support portion 6S has a plate-shaped base portion 6B connected to the elastic deformation portion 6E, and a bent portion 6N bent from the base portion 6B into an L-shape and protruding toward the side (X2 side) where the lens holding member 2 is located. A recess RS (see FIG. 13D) is formed at the tip of the bent portion 6N. The recess RS is a recess that is open on the side where the lens holding member 2 is located. Specifically, the base portion 6B includes a left base portion 6BL that is a part of the left support portion 6SL, and a right base portion 6BR that is a part of the right support portion 6SR. The bent portion 6N includes a left bent portion 6NL that is a part of the left support portion 6SL, and a right bent portion 6NR that is a part of the right support portion 6SR. The recess RS is formed at the tip of each of the left bent portion 6NL and the right bent portion 6NR with the same shape and size. As shown in Fig. 14D, a portion of the piezoelectric driving unit PD is located within the recess RS and is in contact with the inner edge BE of the recess RS, and is fixed to the bent portion 6N by adhesive AD as shown in Fig. 15B. Note that, for clarity, Fig. 14D shows a gap between the bent portion 6N and the piezoelectric driving unit PD (circuit board 10), but in reality, the bent portion 6N and the piezoelectric driving unit PD (circuit board 10) are in contact with each other.

[0053] More specifically, as shown in Fig. 14D, the recess RS has an upper edge portion UE and a lower edge portion DE that face each other with an inner edge portion BE therebetween, and the piezoelectric driver PD is disposed between the upper edge portion UE and the lower edge portion DE.

[0054] The position where the inner edge BE of the recess RS contacts the piezoelectric actuator PD corresponds to the node position ND of the piezoelectric actuator PD that realizes bending vibration, as shown in Fig. 12A. The node positions ND include a first position ND1 and a second position ND2. In Fig. 12A, the node positions ND are marked with a cross pattern for clarity.

[0055] The position where the inner edge BE of the recess RS contacts the piezoelectric driver PD corresponds to a position at a predetermined distance from the end of the piezoelectric driver PD. The predetermined distance is, for example, approximately one-quarter of the total length of the piezoelectric driver PD. That is, a first position ND1, which is one of the positions where the inner edge BE of the recess RS contacts the piezoelectric driver PD, is located at a distance DX1 from the left end LE of the piezoelectric driver PD. The distance DX1 is approximately one-quarter of the total length (length in the Y-axis direction) of the piezoelectric driver PD. Similarly, a second position ND2, which is another one of the positions where the inner edge BE of the recess RS contacts the piezoelectric driver PD, is located at a distance DX2 from the right end RE of the piezoelectric driver PD. The distance DX2 is approximately one-quarter of the total length of the piezoelectric driver PD.

[0056] The piezoelectric driver PD and the bent portion 6N are fixed by an adhesive AD, as shown in Figs. 15A and 15B. In this embodiment, the adhesive AD is an ultraviolet-curing adhesive. However, the adhesive AD may be another type of adhesive, such as a moisture-curing or heat-curing adhesive. The adhesive AD is attached between one surface of the bent portion 6N and the piezoelectric driver PD, and between the other surface of the bent portion 6N and the piezoelectric driver PD.

[0057] 12A, the adhesive AD is applied to a first position ND1 and a second position ND2 on the surface of the front side (X1 side) of the circuit board 10. That is, the adhesive AD includes an adhesive AD applied to the first position ND1 and an adhesive AD applied to the second position ND2. Then, the biasing member 6 is pressed against the front surface of the circuit board 10 so that the adhesive AD applied to the front surface of the circuit board 10 is crushed by a recess RS provided at the tip of the bent portion 6N.

[0058] 15A, the adhesive AD applied to the first position ND1 is divided into an adhesive AD1L that adheres between the left side surface of the left bending portion 6NL and the piezoelectric driver PD, and an adhesive AD1R that adheres between the right side surface of the left bending portion 6NL and the piezoelectric driver PD. Similarly, the adhesive AD applied to the second position ND2 is divided into an adhesive AD2L that adheres between the left side surface of the right bending portion 6NR and the piezoelectric driver PD, and an adhesive AD2R that adheres between the right side surface of the right bending portion 6NR and the piezoelectric driver PD.

[0059] As shown in Fig. 13A, the two elastic deformation parts 6E extend in directions away from each other from the corresponding base parts 6B. Specifically, the left elastic deformation part 6EL extends leftward (Y1 direction) from the left base part 6BL, and the right elastic deformation part 6ER extends rightward (Y2 direction) from the right base part 6BR. The extension direction of the elastic deformation part 6E is aligned with the Y-axis direction, which is the extension direction of the piezoelectric element 8, as shown in Fig. 14C.

[0060] A fixed portion 6F is provided on an extension line of the elastic deformation portion 6E. The fixed portion 6F is clamped by a clamping portion 7C provided on the base member 7, as shown in FIG. 16B. Specifically, the clamping portion 7C has a cylindrical protrusion PL extending upward (in the Z1 direction) from the upper surface of the base member 7, and an L-shaped corner wall portion CN formed at a corner of the base member 7 in a plan view. The fixed portion 6F of the biasing member 6 is clamped between the protrusion PL and the corner wall portion CN by being fitted between them from above. The clamping of the fixed portion 6F by the clamping portion 7C may be achieved by an adhesive, or may be reinforced by an adhesive.

[0061] In this embodiment, as shown in Fig. 13A and Fig. 13B, an opening 6H is formed in the base 6B of the biasing member 6. Specifically, the opening 6H includes a left opening 6HL formed in the left base 6BL of the left support part 6SL and a right opening 6HR formed in the right base 6BR of the right support part 6SR. The left opening 6HL is formed so that the connection state between the left bent part 6NL and the piezoelectric driving part PD can be visually confirmed from the front side (X1 side). The connection state is, for example, whether or not the adhesive AD1L is appropriately arranged. Similarly, the right opening 6HR is formed so that the connection state between the right bent part 6NR and the piezoelectric driving part PD can be visually confirmed from the front side (X1 side). The connection state is, for example, whether or not the adhesive AD2R is appropriately arranged.

[0062] The biasing member 6 has a connecting portion 6C that connects the two base portions 6B. Specifically, as shown in Figures 13A and 13B, the biasing member 6 has an upper connecting portion 6CU and a lower connecting portion 6CD that connect the left base portion 6BL and the right base portion 6BR.

[0063] Next, a camera module CM including the above-mentioned lens driving device 101 will be described with reference to Fig. 17. Fig. 17 is a block diagram showing a configuration example of the camera module CM. In Fig. 17, for clarity, some of the members constituting the camera module CM are omitted from the illustration.

[0064] The camera module CM mainly includes a substrate (not shown), a lens driving device 101 including a lens holding member 2, a lens body (not shown) attached to the lens holding member 2, an image sensor IM mounted on the substrate so as to face the lens body, and a control device CTR configured to drive a piezoelectric driving unit PD to move the lens holding member 2 in the optical axis direction.

[0065] 17, the control device CTR is mounted on a board on which the lens driving device 101 and the image sensor IM are mounted. However, the control device CTR may be provided inside the housing HS constituting the lens driving device 101, or may be mounted on another board outside the housing HS (a board different from the board on which the lens driving device 101 and the image sensor IM are mounted).

[0066] In this embodiment, the control device CTR is composed of a computer including a CPU, a volatile storage device, and a non-volatile storage device. The control device CTR reads out a program corresponding to each function from the non-volatile storage device, loads it into the volatile storage device, and causes the CPU to execute the corresponding process. Each function is, for example, an automatic focus adjustment function and a cleaning function. The processes corresponding to the automatic focus adjustment function and the cleaning function are composed of a process of moving the lens holding member 2 upward in a direction away from the image sensor IM, a process of moving the lens holding member 2 downward in a direction approaching the image sensor IM, and a process of stopping the lens holding member 2 at the current position. The control device CTR may be composed of an ASIC, an FPGA, or the like.

[0067] More specifically, the control device CTR is configured to receive a signal output by the sensor 12 and detect the position (height) of the lens holding member 2 in the Z-axis direction (optical axis direction) based on the signal. The control device CTR is also configured to apply a voltage to a piezoelectric element 8 constituting the piezoelectric driving unit PD via the circuit board 10 to vibrate the piezoelectric element 8, thereby moving the lens holding member 2 in the up-down direction (optical axis direction).

[0068] The control device CTR is also configured to be able to switch the operation mode of the lens driving device 101 between at least a normal mode and a cleaning mode.

[0069] The normal mode is an operation mode selected when the camera function is used in a mobile device equipped with the camera module CM. In this embodiment, the normal mode is selected for a period from when the use of the camera function is started to when the use of the camera function is ended. Specifically, the normal mode is selected for a period from when an operation to activate the camera function is performed to when an operation to stop the camera function is performed.

[0070] The cleaning mode is an operation mode selected when removing wear powder within the first contact range from the first contact range. The first contact range is a range on the surface of the receiving member 11 that the contact member 9 can contact when the normal mode is selected. The wear powder originates from the contact member 9 made of a magnetic member or the receiving member 11 which is a magnet, i.e., has magnetism, and is therefore magnetically attracted to the surface of the receiving member 11 without falling from the contact portion between the contact member 9 and the receiving member 11.

[0071] In the cleaning mode, the wear powder adsorbed within the first contact range is pushed out of the first contact range within the second contact range by the contact member 9. The second contact range is a range on the surface of the receiving member 11 that can be contacted by the contact member 9 when the cleaning mode is selected, and is wider than the first contact range and completely includes the first contact range.

[0072] The cleaning mode is preferably selected when a predetermined start condition is satisfied. The predetermined start condition is, for example, when the power supply of the camera module CM is turned on, when an operation to start the camera function is performed, when an operation to stop the camera function is performed, or when an operation to start the cleaning function is performed. The cleaning mode may be selected when the time elapsed since the last cleaning function was performed exceeds a preset period and when the predetermined start condition is satisfied. In other words, even if the predetermined start condition is satisfied, the cleaning mode may not be selected when the time elapsed since the last cleaning function was performed does not reach the preset period.

[0073] The cleaning function is a function for pushing out wear powder within the first contact range to the outside of the first contact range. Specifically, the cleaning function includes at least a function of moving the lens holding member 2 to the upper limit of the second contact range and a function of moving the lens holding member 2 to the lower limit of the second contact range.

[0074] The cleaning mode selected when the operation to activate the camera function is performed is switched to the normal mode when the cleaning function is completed.

[0075] Next, the cleaning function executed by the control device CTR will be described with reference to Fig. 18A1, Fig. 18A2, Fig. 18B1, Fig. 18B2, Fig. 19, Fig. 20A to Fig. 20E, and Fig. 21A to Fig. 21C. Fig. 18A1, Fig. 18A2, Fig. 18B1, and Fig. 18B2 are diagrams showing the positional relationship between the piezoelectric driving unit PD and the receiving member 11 when the cleaning function is executed.

[0076] Specifically, Fig. 18A1 is a front view of the receiving member 11, and Fig. 18A2 is a left side view of the piezoelectric drive unit PD and the receiving member 11. Fig. 18B1 is a front view of a receiving member 11A, which is another configuration example of the receiving member 11, and Fig. 18B2 is a left side view of the piezoelectric drive unit PD and the receiving member 11A. The receiving member 11A is a magnet that is bipolarly magnetized in the X-axis direction, which is different from the receiving member 11 that is a magnet that is bipolarly magnetized in the Z-axis direction that is the optical axis direction. Note that in Figs. 18A1, 18A2, 18B1, and 18B2, a cross pattern is applied to the N-pole portion, and a dot pattern is applied to the S-pole portion.

[0077] 19 is a flow chart showing an example of the flow of a process for determining whether or not to execute the cleaning function (hereinafter, referred to as "determination process") The control device CTR repeatedly executes this determination process at a predetermined control period.

[0078] 20A to 20E are left side views of the piezoelectric drive unit PD and the receiving member 11, showing the position of the contact point CP between the piezoelectric drive unit PD (contact member 9) and the receiving member 11 when the cleaning function is performed. Specifically, FIG. 20A shows the state of the piezoelectric drive unit PD and the receiving member 11 when the contact point CP is at the center CL of the first contact range MS1, FIG. 20B shows the state of the piezoelectric drive unit PD and the receiving member 11 when the contact point CP is at the lower limit DM1 of the first contact range MS1, and FIG. 20C shows the state of the piezoelectric drive unit PD and the receiving member 11 when the contact point CP is at the upper limit UM1 of the first contact range MS1. Also, FIG. 20D shows the state of the piezoelectric drive unit PD and the receiving member 11 when the contact point CP is at the lower limit DM2 of the second contact range MS2, and FIG. 20E shows the state of the piezoelectric drive unit PD and the receiving member 11 when the contact point CP is at the upper limit UM2 of the second contact range MS2. The lower limit DM1 is the position closest to the imaging element IM in the first contact range MS1, and the upper limit UM1 corresponds to the position farthest from the imaging element IM in the first contact range MS1. The lower limit DM2 is the position closest to the imaging element IM in the second contact range MS2, and the upper limit UM2 corresponds to the position farthest from the imaging element IM in the second contact range MS2.

[0079] 21A to 21C are front views of the receiving member 11, showing how the wear powder AP (upper wear powder AP1 and lower wear powder AP2) in the first contact range MS1 is pushed out of the first contact range MS1 by the cleaning function. Specifically, FIG. 21A shows the state of the receiving member 11 when the contact point CP is at the center CL of the first contact range MS1, FIG. 21B shows the state of the receiving member 11 when the contact point CP subsequently reaches the upper limit UM2 of the second contact range MS2, and FIG. 21C shows the state of the receiving member 11 when the contact point CP subsequently reaches the lower limit DM2 of the second contact range MS2. In addition, in FIGS. 21A and 21B, the wear powder AP adsorbed to the receiving member 11 in the first contact range MS1 is represented by a dot pattern, and in FIGS. 21B and 21C, the wear powder BP (upper wear powder BP1 and lower wear powder BP2) that is the wear powder AP pushed out of the first contact range MS1 is represented by a cross pattern. The wear powder AP is wear powder originating from at least one of the contact member 9 and the receiving member 11.

[0080] 18A1 and 18A2, the receiving member 11 is composed of a two-pole magnet, with the upper portion magnetized to the N pole and the lower portion magnetized to the S pole. Therefore, as shown in Figs. 21A to 21C, the wear powder AP is attracted to the surface of the receiving member 11 by the magnetic force of the receiving member 11 and does not fall from the surface of the receiving member 11.

[0081] Here, the flow of the determination process executed by the control device CTR will be described with reference to Fig. 19. As shown in Fig. 19, the control device CTR determines whether or not the start condition of the cleaning function is satisfied (step ST1). In this embodiment, the control device CTR determines that the start condition of the cleaning function is satisfied when an operation to activate the camera function is performed by the operator of the portable device.

[0082] When it is determined that the start condition of the cleaning function is not satisfied (NO in step ST1), the control device CTR ends the current determination process.

[0083] When it is determined that the start condition of the cleaning function is satisfied (YES in step ST1), the control device CTR moves the lens holding member 2 upward (step ST2). In this embodiment, the control device CTR positions the lens holding member 2 at the initial position so that the contact point CP between the piezoelectric driving unit PD (contact member 9) and the receiving member 11 is located at the center CL of the first contact range MS1 when the lens driving device 101 is in the initial state. The initial state is the state of the lens driving device 101 when the camera function is not activated. The initial position is the position of the lens holding member 2 when the lens driving device 101 is in the initial state. Specifically, the control device CTR is configured to return the lens holding member 2 to the initial position when the camera function is stopped. Note that FIG. 20A shows the positional relationship between the piezoelectric driving unit PD (contact member 9) and the receiving member 11 when the lens driving device 101 is in the initial state.

[0084] Specifically, the control device CTR is configured to move the lens holding member 2, which is in the initial position, upward when the cleaning function is started. However, the control device CTR may be configured to move the lens holding member 2, which is in the initial position, downward when the cleaning function is started. The control device CTR may also determine the moving direction of the lens holding member 2 according to the current position of the lens holding member 2. For example, the control device CTR may move the lens holding member 2 downward when the current position of the lens holding member 2 is lower than the initial position, and may move the lens holding member 2 upward when the current position of the lens holding member 2 is higher than the initial position. The control device CTR may also be configured to move the lens holding member 2 in a predetermined direction (upward or downward) regardless of the current position of the lens holding member 2.

[0085] Thereafter, the control device CTR judges whether the lens holding member 2 has reached the upper set position (step ST3). In this embodiment, the control device CTR specifies the current position of the lens holding member 2 moving upward based on the output of the sensor 12. The upper set position is the position of the lens holding member 2 when the contact point CP crosses the lower limit DM1 of the first contact range MS1 and reaches the lower limit DM2 of the second contact range MS2. The figure G1 represented by the dashed line in FIG. 18A2 indicates the position of the receiving member 11 when the lens holding member 2 has reached the upper set position. Also, FIG. 20B shows the state when the contact point CP has reached the lower limit DM1 of the first contact range MS1, and FIG. 20D shows the state when the contact point CP has reached the lower limit DM2 of the second contact range MS2, that is, the state when the lens holding member 2 has reached the upper set position.

[0086] When it is determined that the lens holding member 2 has not reached the upper set position (NO in step ST3), the control device CTR repeats the determination in step ST3 until the lens holding member 2 reaches the upper set position.

[0087] When it is determined that the lens holding member 2 has reached the upper set position (YES in step ST3), the control device CTR moves the lens holding member 2 downward (step ST4). In this embodiment, the control device CTR reverses the upward movement of the lens holding member 2 to a downward movement.

[0088] Thereafter, the control device CTR judges whether the lens holding member 2 has reached the lower set position (step ST5). In this embodiment, the control device CTR identifies the current position of the lens holding member 2 moving downward based on the output of the sensor 12. The lower set position is the position of the lens holding member 2 when the contact point CP crosses the lower limit DM1 of the first contact range MS1, crosses the center CL of the first contact range MS1, crosses the upper limit UM1 of the first contact range MS1, and reaches the upper limit UM2 of the second contact range MS2. The figure G2 represented by the dashed line in FIG. 18A2 indicates the position of the receiving member 11 when the lens holding member 2 has reached the lower set position. Furthermore, Figure 20B shows the state when contact point CP reaches the lower limit DM1 of the first contact range MS1, Figure 20A shows the state when contact point CP reaches the center CL of the first contact range MS1, Figure 20C shows the state when contact point CP reaches the upper limit UM1 of the first contact range MS1, and Figure 20E shows the state when contact point CP reaches the upper limit UM2 of the second contact range MS2, i.e., the state when the lens holding member 2 reaches the lower set position.

[0089] When it is determined that the lens holding member 2 has not reached the lower set position (NO in step ST5), the control device CTR repeats the determination in step ST5 until the lens holding member 2 reaches the lower set position.

[0090] When it is determined that the lens holding member 2 has reached the lower set position (YES in step ST5), the control device CTR moves the lens holding member 2 upward (step ST6). In this embodiment, the control device CTR reverses the downward movement of the lens holding member 2 to an upward movement again.

[0091] Thereafter, the control device CTR judges whether the lens holding member 2 has reached the center setting position (step ST7). In this embodiment, the control device CTR specifies the current position of the lens holding member 2 moving upward based on the output of the sensor 12. The center setting position is the position of the lens holding member 2 when the contact point CP crosses the upper limit UM1 of the first contact range MS1 and reaches the center CL of the first contact range MS1. In other words, the center setting position is the initial position. FIG. 20C shows the state when the contact point CP reaches the upper limit UM1 of the first contact range MS1, and FIG. 20A shows the state when the contact point CP reaches the center CL of the first contact range MS1, that is, the state when the lens holding member 2 has reached the center setting position. Note that the center setting position may be the position of the lens holding member 2 when the contact point CP reaches a position other than the center CL of the first contact range MS1.

[0092] When it is determined that the lens holding member 2 has not reached the central setting position (NO in step ST7), the control device CTR repeats the determination in step ST7 until the lens holding member 2 reaches the central setting position.

[0093] When it is determined that the lens holding member 2 has reached the central setting position (YES in step ST7), the control device CTR stops the movement of the lens holding member 2 (step ST8). In this embodiment, the control device CTR stops the movement of the lens holding member 2 by ceasing the application of voltage to the piezoelectric element 8 and stopping the movement of the piezoelectric driving unit PD.

[0094] Through this judgment process, the control device CTR can push away the wear powder that is adsorbed to the portion of the surface of the receiving member 11 within the first contact range MS1, outside the first contact range MS1, while still remaining adsorbed to the surface of the receiving member 11.

[0095] Specifically, by executing the cleaning function, the control device CTR can push away upper wear powder AP1 adsorbed on the surface of the receiving member 11 between the center CL and upper limit UM1 of the first contact range MS1, and lower wear powder AP2 adsorbed on the surface of the receiving member 11 between the center CL and lower limit DM1 of the first contact range MS1, as shown in FIG. 21A, outside the first contact range MS1.

[0096] More specifically, the control device CTR can move the contact point CP from the center CL of the first contact range MS1 to the upper limit UM2 of the second contact range MS2, passing the upper limit UM1 of the first contact range MS1, by moving the lens holding member 2 from the initial position (center set position) to the lower set position. As a result, the control device CTR can push away the upper wear powder AP1 that has been adsorbed to the surface of the receiving member 11 between the center CL and the upper limit UM1 of the first contact range MS1, above the upper limit UM2 of the second contact range MS2, as shown in Fig. 21B. The upper wear powder BP1 in Fig. 21B is the upper wear powder AP1 that has been pushed away to the outside (upper side) of the second contact range MS2.

[0097] Moreover, the control device CTR can move the contact point CP from the center CL of the first contact range MS1 beyond the lower limit DM1 of the first contact range MS1 to the lower limit DM2 of the second contact range MS2 by moving the lens holding member 2 from the initial position (center set position) to the upper set position. As a result, the control device CTR can push away the lower wear powder AP2 that has been adsorbed to the surface of the receiving member 11 between the center CL and the lower limit DM1 of the first contact range MS1 to a position lower than the lower limit DM2 of the second contact range MS2, as shown in Fig. 21C. The lower wear powder BP2 in Fig. 21C is the lower wear powder BP2 that has been pushed away to the outside (lower side) of the second contact range MS2.

[0098] 19, the control device CTR realizes the cleaning function by executing one cleaning operation consisting of moving the lens holding member 2 from the current position or the initial position (center setting position) to the upper setting position, moving from the upper setting position to the lower setting position, and moving from the lower setting position to the initial position (center setting position). However, the control device CTR may repeat the cleaning operation two or more times.

[0099] Alternatively, the control device CTR may be configured to execute, at separate timings, one lower cleaning operation consisting of moving the lens holding member 2 from its current position or initial position (center setting position) to an upper setting position and from the upper setting position to the initial position (center setting position), and one upper cleaning operation consisting of moving the lens holding member 2 from its current position or initial position (center setting position) to a lower setting position and from the lower setting position to the initial position (center setting position). For example, the control device CTR may be configured to execute one lower cleaning operation when an operation is performed to activate the camera function, and execute one upper cleaning operation when an operation is performed to stop the camera function.

[0100] Alternatively, the control device CTR may be configured to move the lens holding member 2 to the closer of the upper set position or the lower set position when an operation to stop the camera function is performed. In this case, if the lens holding member 2 has been moved to the upper set position when the camera function is stopped, the control device CTR can push out the wear powder within the first contact range MS1 to the outside of the first contact range MS1 by moving the lens holding member 2 to the lower set position when an operation to start the camera function is subsequently performed, that is, by executing the upper cleaning operation. The same applies to the case where the lens holding member 2 has been moved to the lower set position when the camera function is stopped.

[0101] Also, the control device CTR may be configured to repeat the upper cleaning operation two or more times, and may be configured to repeat the lower cleaning operation two or more times.

[0102] 2, the lens driving device 101 according to the embodiment of the present invention includes a fixed member FB, a lens holding member 2 capable of holding a lens body, a guide mechanism GM that guides the lens holding member 2 movably in the optical axis direction relative to the fixed member FB, a piezoelectric driving unit PD that is configured to have at least a piezoelectric element 8 extending in a direction intersecting the optical axis direction and that moves the lens holding member 2 in the optical axis direction, and a biasing member 6 that biases the piezoelectric driving unit PD toward the lens holding member 2. The lens holding member 2 is configured to be driven by the movement (circular movement in the above embodiment) of the piezoelectric element 8.

[0103] The lens holding member 2 is provided with a receiving member 11 that faces the piezoelectric driving unit PD so as to come into contact with it and extends in a direction (Z-axis direction) intersecting the extension direction (Y-axis direction) of the piezoelectric element 8. The piezoelectric driving unit PD has a contact member 9 that comes into contact with the receiving member 11 on the surface of the piezoelectric element 8 on the lens holding member 2 side (the surface on the X2 side). Both the contact member 9 and the receiving member 11 are made of a magnetic material, and at least one of them is configured to be a magnet.

[0104] With this configuration, the lens driving device 101 can prevent wear powder from falling from the contact portion between the piezoelectric driving unit PD (contact member 9) and the lens holding member 2 (receiving member 11). This is because the wear powder is attracted by the contact member 9 or the receiving member 11, which are made of magnets. Therefore, the lens driving device 101 can prevent wear powder from adhering to the imaging element IM and impairing the quality of the captured image.

[0105] Preferably, the receiving member 11 is configured to be a magnet. In the above-described embodiment, the contact member 9 is a friction plate made of stainless steel, and the receiving member 11 is a metal magnet. This is because the contact member 9 is configured to perform bending vibration (circular motion). In other words, the surface of the receiving member 11 does not deform even while the lens holding member 2 is moving up and down, and is therefore suitable for attracting wear powder.

[0106] With this configuration, the receiving member 11 can adsorb wear powder generated at the contact portion between the piezoelectric drive unit PD and the lens holding member 2, further preventing wear powder from falling from the contact portion between the piezoelectric drive unit PD and the lens holding member 2.

[0107] As shown in Figs. 18A1 and 18A2, the receiving member 11 may be magnetized so that the upper portion, which is one side along the optical axis direction, and the lower portion, which is the other side, have different magnetic poles. This configuration provides the effect that the receiving member 11 can be easily magnetized. Alternatively, the receiving member 11 may be magnetized so that the inner portion located on the optical axis JD side (X2 side) and the outer portion located on the piezoelectric driving unit PD side (X1 side) have different magnetic poles, as in the receiving member 11A as another configuration example shown in Figs. 18B1 and 18B2. This configuration provides the effect that the area that can strongly adsorb wear powder is larger than the configuration shown in Figs. 18A1 and 18A2. This is because the magnetic force is weakened on the boundary between the N pole portion and the S pole portion in the configuration shown in Figs. 18A1 and 18A2.

[0108] The material constituting each of the receiving member 11 and the contact member 9 is preferably a metal. The metal constituting the receiving member 11 is preferably harder than the metal constituting the contact member 9. In the above embodiment, the receiving member 11 is configured to have a surface hardness higher than that of the contact member 9. This is because the higher the surface hardness, the less likely it is that wear powder will be generated. In addition, the contact member 9 desirably has a relatively low surface hardness so that bending vibration (circular motion) is performed smoothly. In other words, this is to prevent the high surface hardness of the contact member 9 from interfering with the smooth bending vibration of the contact member 9. The receiving member 11 may be subjected to a nitriding treatment (surface hardening treatment) such as a salt bath soft nitriding treatment. In this case, the receiving member 11 is formed of stainless steel.

[0109] However, as long as the excessive generation of wear powder originating from each of the contact member 9 and the receiving member 11 can be suppressed, the receiving member 11 may be configured so that its surface hardness is approximately the same as the surface hardness of the contact member 9, or may be configured so that its surface hardness is lower than the surface hardness of the contact member 9.

[0110] Furthermore, in the lens driving device 101, both the receiving member 11 and the contact member 9 may be made of magnets. This configuration can further prevent wear powder from falling from the contact portion between the piezoelectric driving unit PD and the lens holding member 2. This is because the wear powder is attracted not only to the surface of the receiving member 11 but also to the surface of the contact member 9.

[0111] As shown in FIG. 17, the camera module CM according to the embodiment of the present invention includes a lens driving device 101, an image pickup element IM facing the lens body, and a control device CTR that drives the piezoelectric driving unit PD so that the piezoelectric element 8 moves (in the above embodiment, circular motion) to move the lens holding member 2 in the optical axis direction. As shown in FIG. 2, the lens holding member 2 is provided with a receiving member 11 that faces the piezoelectric driving unit PD so as to come into contact with it and extends in a direction (Z-axis direction) intersecting the extension direction (Y-axis direction) of the piezoelectric element 8. The piezoelectric driving unit PD has a contact member 9 that comes into contact with the receiving member 11 on the inner surface (X2 side surface) of the piezoelectric element 8. The inner side of the piezoelectric element 8 is the side where the lens holding member 2 is located. The control device CTR is configured to be able to switch the operation mode of the lens driving device 101 between a normal mode and a cleaning mode. As shown in Figures 20A to 20E, a first contact range MS1, which is the area on the surface of the receiving member 11 that the contact member 9 can contact when the normal mode is selected, is smaller than a second contact range MS2, which is the area on the surface of the receiving member 11 that the contact member 9 can contact when the cleaning mode is selected.

[0112] With this configuration, the camera module CM can push out wear powder generated within the inner range of the first contact range MS1 to the outside of the first contact range MS1. Therefore, the camera module CM can suppress the occurrence of a problem in which, for example, wear powder accumulated inside the first contact range MS1 prevents contact between the contact member 9 and the receiving member 11, and prevents the lens holding member 2 to which the receiving member 11 is attached from moving in the up-down direction (optical axis direction). Specifically, the camera module CM can suppress the occurrence of a problem in which the movable range is limited by wear powder accumulated in the first contact range MS1. As a result, the camera module CM can suppress the shortening of its operating life caused by wear powder.

[0113] Moreover, both the receiving member 11 and the contact member 9 are desirably made of a magnetic material, and at least one of the receiving member 11 and the contact member 9 is made of a magnet.

[0114] With this configuration, the camera module CM can prevent wear powder from falling from the contact portion between the piezoelectric driver PD and the lens holding member 2. This is because the wear powder is attracted to the magnet.

[0115] More specifically, the upper limit UM2 of the second contact range MS2 is at a higher position, farther from the image sensor IM than the upper limit UM1 of the first contact range MS1, and the lower limit DM2 of the second contact range MS2 is at a lower position, closer to the image sensor IM than the lower limit DM1 of the first contact range MS1.

[0116] With this configuration, the camera module CM can push out wear powder in the lower portion of the first contact range MS1 to the outside (lower side) of the first contact range MS1, and can push out wear powder in the upper portion of the first contact range MS1 to the outside (upper side) of the first contact range MS1. Therefore, the camera module CM can more reliably suppress the occurrence of a problem in which wear powder accumulated inside the first contact range MS1 prevents contact between the contact member 9 and the receiving member 11, preventing the lens holding member 2 to which the receiving member 11 is attached from moving in the up-down direction.

[0117] The control device CTR preferably switches the operation mode of the lens driving device 101 to the cleaning mode when a predetermined start condition is satisfied. The predetermined condition is, for example, that the power supply of the camera module CM is turned on.

[0118] This configuration brings about an effect that the smooth movement of the lens driving device 101 is maintained for a long period of time. For example, this is because the wear powder accumulated inside the first contact range MS1 is pushed out to the outside of the first contact range MS1 every time the camera module CM is powered on. In other words, when the normal mode is selected as the operation mode of the lens driving device 101, a state in which there is almost no wear powder inside the first contact range MS1 is maintained.

[0119] The preferred embodiments of the present invention have been described above in detail. However, the present invention is not limited to the above-described embodiments. Various modifications or substitutions may be applied to the above-described embodiments without departing from the scope of the present invention. Furthermore, each of the features described with reference to the above-described embodiments may be appropriately combined as long as there is no technical contradiction.

[0120] For example, in the above embodiment, the lens holding member 2 has shafts (the first shaft 2S and the second shaft 2T) and is configured to have no pivotal support, but may be configured to have a pivotal support. In this case, the first link member 3 may be configured to have a shaft corresponding to the pivotal support. The same applies to the second link member 4.

[0121] In the above embodiment, the base member 7 has the pivotal support portions (the third pivotal support portion 7H and the fourth pivotal support portion 7J) and is configured to have no shaft portion, but may be configured to have a shaft portion. In this case, the first link member 3 may be configured to have a pivotal support portion corresponding to the shaft portion. The same applies to the second link member 4.

[0122] In the above embodiment, the first shaft portion 2S is configured to have a left first shaft portion 2SL and a right first shaft portion 2SR, that is, to have a pair of shaft portions, but may be configured as a combination of shaft portions and a support portion. For example, the first shaft portion 2S may be configured to have a left first shaft portion 2SL and a right first support portion (not shown). In this case, the first support portion 3H may be configured to have a left first support portion 3HL and a right first shaft portion (not shown). The same applies to the second shaft portion 2T, the second support portion 4H, the third shaft portion 3S, the third support portion 7H, the fourth shaft portion 4S, and the fourth support portion 7J.

[0123] Furthermore, if the lens body held by the lens holding member 2 is not large and the change in posture when the lens holding member 2 moves in the optical axis direction can be tolerated, the link mechanism LM may be omitted.

[0124] Furthermore, the number of balls 5 in one set arranged between the movable groove portion 2G and the fixed groove portion 7G may be three or more, or may be one.

[0125] Furthermore, the guide mechanism is not limited to one that uses balls. For example, an upper leaf spring and a lower leaf spring may be provided between the lens holding member 2 and the fixed member, and the guide mechanism may be configured by the upper leaf spring and the lower leaf spring.

[0126] This application claims priority based on Japanese Patent Application No. 2021-040548, filed on March 12, 2021, the entire contents of which are incorporated by reference into this application. [Explanation of symbols]

[0127] 1···cabinet member 1A···outer wall portion 1B···ceiling portion 1K···opening 1S···accommodation portion 2···lens holding member 2B···columnar portion 2BL···left columnar portion 2BR···right columnar portion 2C···cylindrical portion 2G···movable side groove portion 2GL···left movable side groove portion 2GR···right movable side groove portion 2S···first shaft portion 2SL···left first shaft portion 2SR···right first shaft portion 2T···second shaft portion 2TB···rear second shaft portion 2TF···front second shaft portion 3···first link member 3A···first wrist portion 3AL···left first wrist portion 3AR· ··Right first wrist portion 3B···1st base portion 3H···1st shaft branch portion 3HL···left first shaft branch portion 3HR···right first shaft branch portion 3S···3rd shaft portion 3SL···left third shaft portion 3SR···right third shaft portion 4···2nd link member 4A···2nd wrist portion 4AB···rear second wrist portion 4AF···front second wrist portion 4B···2nd base portion 4H···2nd shaft branch portion 4HB···rear second shaft branch portion 4HF···front second shaft branch portion 4S···4th shaft portion 4SB···rear fourth shaft portion 4SF···front fourth shaft portion 5···ball 5L···left ball 5 LD···lower left ball 5LU···upper left ball 5R···right ball 5RD···lower right ball 5RU···upper right ball 6···supporting member 6B···base 6BL···left base 6BR···right base 6C···connecting portion 6CD···lower connecting portion 6CU···upper connecting portion 6E···elastic deformed portion 6EL···left elastic deformed portion 6ER···right elastic deformed portion 6F···fixing portion 6FL···left fixing portion 6FR···right fixing portion 6H···opening 6HL···left opening 6HR···right opening 6N···bend portion 6 NL···Left-side folded portion 6NR···Right-side folded portion 6S···Support portion 6SL···Left-side support portion 6SR···Right-side support portion 7···Bess member 7B···Columnar portion 7BL···Left-side columnar portion 7BR···Right-side columnar portion 7C···Clamping portion 7CL···Left-side clamping portion 7CR···Right-side clamping portion 7F···Rectangular beam portion 7G···Fixed side groove portion 7GL···Left fixed side groove portion 7GR···Right fixed side groove portion 7H···Third-side support portion 7HL···Left-side third-side support portion 7HR···Right-side third-side support portion 7J···Fourth-side support portion 7JB···Rear-side fourth-side support portion7JF...Front fourth shaft support 7K...Opening 7V...Recess 7VLD...Lower left recess 7VLU...Upper left recess 7VRD...Lower right recess 7VRU...Upper right recess 7W...Wall 8...Piezoelectric element 8X...Rotating shaft 9...Contact member 10...Circuit board 11...Receiving member 12...Sensor 13...Magnet 14...Sensor circuit board 101...Lens drive unit AD, AD1L, AD1R, AD2L, AD2R...Adhesive AP...Wear powder AP1...Upper wear powder AP2...Lower wear powder BE...Inner edge BP...Wear powder BP1...Upper wear powder BP2...Lower wear powder CL...Center CM...Camera module CN... Corner wall CP... Contact point CTR... Control device DE... Lower edge DM1, DM2... Lower limit FB... Fixed part GM... Guide mechanism GML... Left guide part GMR... Right guide part HS... Housing IM... Image sensor JD... Optical axis LE... Left end LM... Link mechanism MB... Movable part MS1... First contact area MS2... Second contact area ND... Position ND1... First position ND2... Second position PD... Piezoelectric actuator PL... Projection RA1... First rotating axis RA2... Second rotating axis RA3... Third rotating axis RA4... Fourth rotating axis RE... Right end RS... Recess UE... Upper edge UM1, UM2... Upper limit UR1: First recess UR2: Second recess

Claims

1. a lens driving device including: a fixed-side member; a lens holding member capable of holding a lens body; a guide mechanism for guiding the lens holding member so as to be movable in an optical axis direction relative to the fixed-side member; a piezoelectric driving unit having a piezoelectric element extending in a direction intersecting the optical axis direction, the piezoelectric element moving the lens holding member in the optical axis direction; and a biasing member for biasing the piezoelectric driving unit toward the lens holding member; an imaging element facing the lens body; a control device that drives the piezoelectric drive unit to move the lens holding member in an optical axis direction, the lens holding member is provided with a receiving member that faces the piezoelectric driving unit so as to come into contact with the piezoelectric driving unit and extends in a direction intersecting with an extending direction of the piezoelectric element; the piezoelectric driving unit has a contact member that comes into contact with the receiving member on a surface of the piezoelectric element that faces the lens holding member, the control device is configured to switch an operation mode of the lens driving device between a normal mode and a cleaning mode, A camera module characterized in that a first contact range, which is an area on the surface of the receiving member that the contact member can contact when the normal mode is selected, is smaller than a second contact range, which is an area on the surface of the receiving member that the contact member can contact when the cleaning mode is selected.

2. the receiving member and the contact member are made of a magnetic material, At least one of the receiving member and the contact member is a magnet. The camera module of claim 1 .

3. an upper limit of the second contact range is located higher than an upper limit of the first contact range; The lower limit of the second contact range is located lower than the lower limit of the first contact range. The camera module according to claim 1 or 2.

4. the control device switches the operation mode of the lens driving device to the cleaning mode when power is turned on; The camera module according to any one of claims 1 to 3.

5. A fixed member; a lens holding member capable of holding a lens body; a guide mechanism that guides the lens holding member movably in an optical axis direction relative to the fixed member; a piezoelectric driving unit including a piezoelectric element extending in a direction intersecting the optical axis direction, the piezoelectric driving unit moving the lens holding member in the optical axis direction; a biasing member that biases the piezoelectric driving unit toward the lens holding member, and the lens holding member is driven by the movement of the piezoelectric element, the lens holding member is provided with a receiving member that faces the piezoelectric driving unit so as to come into contact with the piezoelectric driving unit and extends in a direction intersecting with an extending direction of the piezoelectric element; the piezoelectric driving unit has a contact member that comes into contact with the receiving member on a surface of the piezoelectric element that faces the lens holding member, The receiving member and the contact member are both made of a magnetic material, At least one of the receiving member and the contact member is a magnet, the receiving member has a first contact range with which the contact member can come into contact when a normal mode is selected by a control device that drives the piezoelectric drive unit to move the lens holding member in the optical axis direction, and a second contact range with which the contact member can come into contact when a cleaning mode is selected by the control device, The first contact area is smaller than the second contact area. A lens driving device comprising:

6. The receiving member is a magnet.

6. The lens driving device according to claim 5.

7. The receiving member is magnetized so that an inner portion located on the optical axis side and an outer portion located on the piezoelectric driving unit side have different magnetic poles.

7. The lens driving device according to claim 6.

8. The receiving member is magnetized so that an upper portion and a lower portion have different magnetic poles.

7. The lens driving device according to claim 6.

9. the receiving member and the contact member are made of a metal, The metal constituting the receiving member is harder than the metal constituting the contact member.

9. The lens driving device according to claim 5, wherein the lens driving device is a lens driving device.

10. The receiving member is made of stainless steel that has been subjected to a nitriding treatment.

10. The lens driving device according to claim 5,

11. The receiving member and the contact member are both magnets.

11. The lens driving device according to claim 5.

Images