JP6242673B2 - Lens drive device - Google Patents

Description

  The present invention relates to a lens driving device that corrects camera shake by moving a lens in a plane orthogonal to an optical axis.

  Conventionally, there is Patent Document 1 as a technology in such a field. Patent Document 1 discloses a camera shake correction device used for a camera. In this camera shake correction device, the autofocus lens driving device is supported so as to be swingable in a direction perpendicular to the optical axis. More specifically, one end side of four suspension wires is fixed to the four corners of the base printed board, and the other end side of the suspension wire is fixed to the printed wiring board of the autofocus lens driving device with an adhesive or solder. Yes.

JP 2011-65140 A

  However, when an impact is applied to the camera shake correction apparatus of Patent Document 1, the printed wiring board on which the suspension wire is fixed may swing excessively, and the printed wiring board may collide with the cover that houses the autofocus lens driving device. There is. When the printed wiring board collides with the cover, a load may be generated at the connection portion between the suspension wire and the printed wiring board, so that it is difficult to improve the shock resistance of the camera shake correction device.

  Therefore, an object of the present invention is to provide a lens driving device that can improve impact resistance.

A lens driving device according to the present invention is disposed on a frame, a movable member that is disposed on the frame and moves in a plane orthogonal to the optical axis, and the frame and the movable member. The movable member driving means for moving the movable member in the orthogonal direction and the support means for movably supporting the movable member in a plane with respect to the frame body, the support means is a movable member attached to the movable member. Yes a connecting member fixed against the magnet member driving means, one end of which is fixed the other end to the frame is fixed to the connecting member, and a wire that movably supports the connecting member in a plane, the Then, the lens frame is fixed to the connecting member via the elastic arm portion of the connecting member, and the connecting member is disposed in the space formed by the movable member.

  In the lens driving device according to the present invention, since the connecting member is fixed with respect to the movable member, the relative positional relationship between the connecting member and the movable member does not change even when the movable member moves. On the other hand, the relative positional relationship between the connecting member and the frame changes as the movable member moves. Here, since the connecting member is arranged in the space formed by the movable member, when the connecting member moves and approaches the frame body, the connecting member does not directly contact the frame body and is movable. A member will contact | abut directly with respect to a frame. This movable member has higher strength than the connection portion between the wire and the connecting member. According to such a configuration, even when an impact is applied to the lens driving device, the impact load on the connection portion between the wire and the connecting member is reduced by the movable member coming into contact with the frame. Therefore, the impact resistance of the lens driving device can be improved.

  The movable member has an isolation wall portion disposed between the frame body and the connecting member in a direction orthogonal to the optical axis. According to this configuration, when an impact acts in a direction orthogonal to the optical axis and the movable member moves in the direction of the impact, the isolation wall portion comes into contact with the frame body. On the other hand, the connecting member whose relative position to the isolation wall portion does not change does not directly contact the frame. Therefore, the impact resistance in the direction orthogonal to the optical axis can be enhanced.

  In addition, the movable member has a protruding wall portion that protrudes from the connecting member in the direction of the optical axis. According to this configuration, when an impact acts in the direction of the optical axis and the movable member moves in the direction of the impact, the protruding wall portion comes into contact with the frame body. On the other hand, the connecting member whose relative position with the protruding wall portion does not change does not directly contact the frame. Therefore, the impact resistance in the optical axis direction can be enhanced.

  According to the present invention, the impact resistance of the lens driving device is increased.

It is a disassembled perspective view of the lens drive device which concerns on this invention. FIG. 2 is a perspective view of the lens driving device shown in FIG. 1. It is a perspective view which shows the cross section of the lens drive device shown by FIG. FIG. 2 is a side view of the lens driving device shown in FIG. 1. FIG. 2 is a plan view of the lens driving device shown in FIG. 1.

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

  The lens driving device is a device applied to a digital still camera, a mobile phone, a smartphone, or the like, and corrects camera shake by changing the optical axis position of the imaging optical system with respect to the imaging element. The lens driving device is disposed and used in front of a CCD (Charge Coupled Device) image sensor or a CMOS (Complementary Metal Oxide Semiconductor) image sensor, which is an imaging device (not shown). In the following description, a lens driving device that employs a method of moving an imaging optical system with respect to a fixed imaging element will be described as an example.

  As shown in FIG. 1, a lens driving device 1 having a camera shake correction function includes a box-shaped case (frame body) 2 and an imaging optical system 3 that adjusts the focus of a lens (not shown). . The case 2 accommodates the imaging optical system 3 therein, and has a flat base plate 4 and a box-shaped cover 5.

  At the corners of the base plate 4, there are provided wire fixing portions 4a for fixing suspension wires 16 to be described later. Further, an input / output terminal 4b for driving current and a desired control signal for driving the imaging optical system 3 and the like is provided at the edge on the back side of the base plate 4. The input / output terminal 4 b is formed integrally with the base plate 4 and connected to a wiring pattern (not shown) disposed inside the base plate 4. For example, the input / output terminal 4b is electrically connected to the wire fixing portion 4a through a wiring pattern. Therefore, a current can be supplied from the input / output terminal 4b to the wire fixing portion 4a. The base plate 4 is provided with a coil C1 for the movable member driving means 11 and a position detection element S for detecting the position of the imaging optical system 3.

  An imaging optical system 3 is disposed on the base plate 4 (see FIG. 2). More specifically, the imaging optical system 3 having the focus adjustment mechanism 6 and the camera shake correction mechanism 7 has a base plate so that the focus adjustment mechanism 6 can be moved in a direction orthogonal to the optical axis C by the camera shake correction mechanism 7. 4 are arranged. That is, the camera shake correction mechanism 7 supports the focus adjustment mechanism 6 and corrects camera shake by moving the focus adjustment mechanism 6 in a plane orthogonal to the optical axis C.

  The camera shake correction mechanism 7 includes a movable member 8 that moves in a plane orthogonal to the optical axis C, and a support unit 9 that movably supports the movable member 8 with respect to the base plate 4. A driving force in a direction orthogonal to the optical axis C is applied to the movable member 8 by the movable member driving means 11 having the coil C1 and the magnet M1.

  The movable member 8 is a frame-shaped member in which a pair of end surfaces orthogonal to the optical axis C are opened, and holds the focus adjustment mechanism 6 therein. The movable member 8 is disposed on the base plate 4 while being supported by the support means 9.

  As shown in FIG. 3, magnets M <b> 1 and M <b> 2 are attached to each corner of the movable member 8. Magnets M1 and M2 are fixed to movable member 8 with metal yoke 12 interposed therebetween. The movable member 8 also functions as a yoke for forming the magnetic paths of the magnets M1 and M2. By using the movable member 8 as a yoke, the magnetic flux can be prevented from leaking to the outside and the magnetic efficiency can be improved. These magnets M1 cooperate with the coil C1 disposed on the base plate 4 so as to face the direction of the optical axis C, and provide a driving force for driving the movable member 8 in a direction perpendicular to the optical axis C. generate. That is, the magnet M1 and the coil C1 constitute the movable member driving means 11.

  As shown in FIG. 1, the support means 9 supports the movable member 8 so as to be movable with respect to the base plate 4. The support means 9 includes a pair of leaf springs 13 and 14 fixed to the movable member 8 and four suspension wires 16 that movably support the leaf spring 13.

  The pair of leaf springs 13, 14 gives the urging force in the direction along the optical axis C to the movable member 8 to the focus adjustment mechanism 6. One leaf spring (connecting member) 13 is disposed on the cover 5 side on the optical axis C, and the other leaf spring 14 is disposed on the base plate 4 side on the optical axis C. The leaf springs 13 and 14 are arranged so as to sandwich the movable member 8 in the direction of the optical axis C. The leaf spring 13 constitutes a part of a current path for supplying a current to a coil C2 disposed in the focus adjusting mechanism 6 described later.

  As shown in FIGS. 2 and 3, one leaf spring 13 includes a frame portion 17 that is fixed to the movable member 8, a lens frame fixing portion 18 that is fixed to a lens frame 21 described later, The frame portion 17 and the lens frame fixing portion 18 are connected to each other, and an elastic arm portion 19 that generates an urging force along the direction of the optical axis C is provided.

  As shown in FIG. 3, the frame portion 17 has a magnet fixing portion 17a and a wire fixing portion 17b. The magnet fixing portion 17a is bonded and fixed to the magnets M1 and M2 fixed to the movable member 8. The wire fixing portion 17 b is formed outside the magnet fixing portion 17 a in the diagonal direction of the movable member 8. A suspension wire 16 is fixed to the wire fixing portion 17b provided at the corner of the frame portion 17 by bonding or soldering.

  The suspension wire 16 supports the leaf spring 13 with respect to the base plate 4 so as to be movable in a plane orthogonal to the optical axis C. The suspension wire 16 is disposed between the base plate 4 and the plate spring 13, one end side is fixed to the wire fixing portion 4 a of the base plate 4, and the other end side is fixed to the wire fixing portion 17 b of the plate spring 13. Since the suspension wire 16 is longer than the thickness of the movable member 8 in the direction of the optical axis C, a gap is formed between the end surface of the movable member 8 on the base plate 4 side and the base plate 4. That is, the movable member 8 is attached to the base plate 4 in a state of floating in the air.

  The suspension wire 16 constitutes a part of a current path for supplying a current to a coil C2 disposed in the focus adjusting mechanism 6 described later. A wiring pattern electrically connected to the input / output terminal 4b (see FIG. 1) is disposed on the wire fixing portion 4a of the base plate 4 to which one end side of the suspension wire 16 is fixed. Accordingly, the suspension wire 16 is fixed to the wire fixing portion 4a, whereby the suspension wire 16 and the input / output terminal 4b are electrically connected. Furthermore, since the other end side of the suspension wire 16 is fixed to the leaf spring 13, a current path from the input / output terminal 4b to the leaf spring 13 is formed.

  Here, the relationship among the leaf spring 13, the movable member 8, and the case 2 will be described in detail. As shown in FIG. 5, the leaf spring 13 is disposed in a space formed by the movable member 8. More specifically, the space formed by the movable member 8 refers to a region surrounded by the side wall of the movable member 8, in other words, a region surrounded by the inner wall surface 8a (see FIG. 1) of the movable member 8. is there. In this region, a lens frame fixing portion 18 of the leaf spring 13, an elastic arm portion 19, and a magnet fixing portion 17 a in the frame portion 17 are arranged. This region is surrounded by an isolation wall 8b that forms an end of the movable member 8 on the cover 5 side in a direction perpendicular to the optical axis C. In other words, the isolation wall portion 8 b of the movable member 8 is disposed between the lens frame fixing portion 18, the elastic arm portion 19 and the magnet fixing portion 17 a of the plate spring 13 and the cover 5.

  Further, the space formed by the movable member 8 includes a region surrounded by an annular virtual surface K including an outer peripheral surface facing the cover 5 in each isolation wall portion 8b. The region surrounded by the virtual surface K includes the inner wall surface 8a of the movable member 8 at the notch 8c provided in the movable member 8 in addition to the region surrounded by the inner wall surface 8a of the movable member 8 described above. A region formed between the surface and the virtual surface K is included. In a region formed between the inner wall surface 8a of the movable member 8 and the virtual surface K, a wire fixing portion 17b in the frame portion 17 is disposed. The wire fixing portion 17b is located outside the area surrounded by the inner wall surface 8a of the movable member 8, but is located inside the area surrounded by the virtual plane K. Therefore, even when the outer peripheral surface 8 d of the movable member 8 contacts the inner wall surface 5 a (see FIG. 1) of the cover 5 facing the wire fixing portion 17 b does not contact the inner wall surface of the cover 5.

  Further, as shown in FIGS. 3 and 4, the movable member 8 has a protruding wall portion 8 e protruding in the direction of the optical axis C from the upper surface of the plate spring 13 toward the cover 5. The movable member 8 of the present embodiment has a structure in which the isolation wall portion 8b also serves as the protruding wall portion 8e. Accordingly, the leaf spring 13 is disposed on the inner side of the end surface of the movable member 8 on the cover 5 side. In other words, the leaf spring 13 is disposed at a position that is lowered inward from the end surface of the movable member 8 on the cover 5 side. Therefore, even when the movable member 8 moves to the cover 5 side in the direction of the optical axis C, and the end surface of the movable member 8 on the cover 5 side contacts the bottom surface of the cover 5, the leaf spring 13 is attached to the cover 5. Do not touch the bottom.

  As shown in FIG. 1, the other leaf spring 14 is, like the leaf spring 13, a frame portion 17 that is fixed to the movable member 8 and a lens frame fixing portion 18 that is fixed to the lens frame 21. And an elastic arm portion 19 that couples the frame portion 17 and the lens frame fixing portion 18 and generates an urging force along the direction of the optical axis C. The frame portion 17 of the leaf spring 14 has the same shape as the frame shape of the movable member 8 on the base plate 4 side, and is bonded to the end surface of the movable member 8 on the base plate 4 side.

  The focus adjustment mechanism 6 includes a lens frame 21 for holding a single lens group or a plurality of lens groups (not shown), and a coil C2 for driving the lens frame 21 in the direction of the optical axis C. A coil C2, which is electrically connected to the leaf spring 13 and supplied with current, cooperates with the magnets M1 and M2 attached to the movable member 8 to drive the lens frame 21 in the direction of the optical axis C. Generate driving force. Thus, the magnets M1, M2 and the coil C2 constitute the lens frame driving means 22.

  Here, the leaf spring 13 is divided into two spring portions that are line-symmetric with respect to an axis orthogonal to the optical axis C, and thus constitutes two independent current paths.

  According to the focus adjustment mechanism 6 having the above-described configuration, the lens frame 21 is moved in the direction of the optical axis C by the lens frame driving means 22 to adjust the focus of the lens. The focus adjustment mechanism 6 may be a zoom mechanism that determines the angle of view.

  In the lens driving device 1, the frame portion 17 of the leaf spring 13 is fixed to the movable member 8 via the magnet M <b> 1 and the yoke 12. Therefore, even if the movable member 8 moves, the relative positional relationship between the frame portion 17 and the movable member 8 does not change. On the other hand, the relative positional relationship between the leaf spring 13 and the case 2 changes as the movable member 8 moves. Here, since the leaf spring 13 is disposed in the space formed by the movable member 8, when the leaf spring 13 moves and approaches the case 2, the leaf spring 13 directly contacts the case 2. Instead, the movable member 8 comes into direct contact with the case 2. The movable member 8 has higher strength than the frame portion 17 including the connection portion between the suspension wire 16 and the leaf spring 13. According to such a configuration, even when an impact is applied to the lens driving device 1, the impact load on the frame portion 17 is reduced by the movable member 8 coming into contact with the case 2. Therefore, impact resistance can be improved.

  The movable member 8 has an isolation wall portion 8b disposed between the case 2 and the leaf spring 13 in a direction orthogonal to the optical axis C. According to this configuration, when an impact is applied in a direction perpendicular to the optical axis C and the movable member 8 moves in the direction of the impact, the isolation wall portion 8 b comes into contact with the cover 5. On the other hand, the frame portion 17 of the leaf spring 13 whose relative position with respect to the isolation wall portion 8 b does not change does not directly contact the cover 5. Therefore, the impact resistance in the direction orthogonal to the optical axis C can be improved.

  The movable member 8 has a protruding wall portion 8e that protrudes from the upper surface of the plate spring 13 in the direction of the optical axis C. According to this configuration, when the impact acts in the direction of the optical axis C and the movable member 8 moves in the direction of the impact, the protruding wall portion 8 e comes into contact with the cover 5. On the other hand, the frame portion 17 of the leaf spring 13, whose relative position with respect to the protruding wall portion 8 e hardly changes, does not directly contact the cover 5. Therefore, the impact resistance in the direction of the optical axis C can be improved.

  Furthermore, when the wire fixing portion 17b of the plate spring 13 to which the suspension wire 16 is fixed is used as a support point, the movable member 8 and the focus adjustment mechanism 6 are supported in a cantilever shape by the plate spring 13. become. According to such a support configuration, when an impact along the direction of the optical axis C (thrust direction) is applied, the wire fixing portion 17b and the magnet fixing portion 17a are supported by the leaf spring 13 with the wire fixing portion 17b as a supporting point. The gap bends in the direction along the optical axis C. This deflection reduces the impact load in the direction along the optical axis C, so that the impact resistance of the lens driving device 1 can be further improved.

  In addition, the lens driving device 1 secures a current supply path to the coil C2 for driving the lens frame 21 without using a complicated mechanism or adding new parts, and the suspension wire 16 and the plate. The connection part with the spring 13 can be protected from impact. Therefore, it is possible to improve impact resistance while suppressing an increase in the size of the lens driving device 1.

  Further, since the wire fixing portion 17b in the leaf spring 13 is protected from impact, it is ensured that the current supply path to the coil C2 by the suspension wire 16 and the support of the movable member 8 are ensured and the lens frame 21 is secured. A structure that can reliably apply the urging force is maintained. Therefore, even when an impact is applied, the securing of the current supply path, the support of the movable member 8, and the application of the urging force to the lens frame 21 can be reliably performed.

  The present invention is not limited to the above-described embodiment, and various modifications as described below are possible without departing from the gist of the present invention.

  The movable member 8 of the camera shake correction mechanism 7 is supported on the base plate 4 and moves with respect to the base plate 4, but is not limited to this configuration. Although not shown, the lens driving device 1 may have a configuration in which the focus adjustment mechanism 6 is disposed on the base plate 4 and the movable member 8 and the frame body are disposed in the focus adjustment mechanism 6. The movable member 8 is arranged on the frame so as to be movable in a plane orthogonal to the optical axis C via the support means 9. A lens is attached to the movable member 8.

DESCRIPTION OF SYMBOLS 1 ... Lens drive device, 2 ... Case (frame body), 3 ... Imaging optical system, 4 ... Base plate, 5 ... Cover, 6 ... Focus adjustment mechanism, 7 ... Correction mechanism, 8 ... Movable member, 8b ... Isolation wall part, 8 ... Projection wall part, 9 ... Support means, 11 ... Drive means for movable member, 12 ... Yoke, 13 ... Leaf spring (connection member), 14 ... Leaf spring, 16 ... Suspension wire (wire), 17 ... Frame part, 17a: Magnet fixing portion, 17b: Wire fixing portion, 18 ... Lens frame fixing portion, 19 ... Elastic arm portion, 21 ... Lens frame, C ... Optical axis, C1, C2 ... Coil, K ... Virtual plane, M1, M2 ... Magnet, S: Position detecting element.

Claims (4)

A frame,
A movable member disposed on the frame and moving in a plane perpendicular to the optical axis;
Movable member driving means arranged on the frame body and the movable member and moving the movable member in a direction orthogonal to the optical axis;
Supporting means for movably supporting the movable member within the plane with respect to the frame body,
The support means is
A fixed connecting member for the magnet of the movable member drive means mounted on the movable member,
A wire having one end fixed to the connecting member and the other end fixed to the frame, and supporting the connecting member movably in the plane;
A lens frame is fixed to the connecting member via an elastic arm portion of the connecting member, and the connecting member is disposed in a space formed by the movable member. .   The lens driving device according to claim 1, wherein the movable member includes an isolation wall portion disposed between the frame body and the connecting member in a direction orthogonal to the optical axis. The lens driving device according to claim 2, wherein the isolation wall portion of the movable member also serves as a yoke that forms a magnetic path of the magnet. Said movable member is a lens driving device according to any one of claims 1, characterized in that it has a projecting wall portion which projects beyond the connecting member in the direction of the optical axis 3.

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