Optical element drive device, camera module and camera-mounted device

Abstract

To provide an optical element drive device capable of inhibiting deterioration in tilt characteristics and displacement of an optical axis and moving an optical element in an optical axis direction with stable posture, a camera module, and a camera-mounted device.SOLUTION: The optical element drive device comprises: a base; a holder to which an optical element can be fitted; a plurality of support parts arranged on a rotationally symmetrical position on an outer peripheral surface of the holder and movably supporting the holder to the base in an optical axis direction; and a drive part moving the holder in an optical axis direction. The support part includes a ball, a ball receiving part rotationally supporting the ball in an optical axis direction, and a biasing part pressing the ball toward the ball receiving part. A biasing force of the biasing part is in an optical axis orthogonal plane orthogonal to the optical axis direction, greater in a first component through the optical axis and the ball and parallel to a radial direction than in a second component orthogonal to the radial direction.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to an optical element driving device, a camera module, and a camera-mounted device.

Background Art

[0002] Generally, a small camera module is mounted on a camera-mounted device such as a smartphone or a drone. A drone is an unmanned aircraft that can be flown by remote control or automatic control, and some are called multicopters.

[0003] An optical element driving device for driving an optical element such as a lens is used in the camera module. The optical element driving device has, for example, an autofocus function (hereinafter referred to as the "AF function", AF: Auto Focus) that automatically focuses by moving an optical element (for example, a lens) in the optical axis direction when photographing a subject (see, for example, Patent Document 1). In addition, some have an optical image stabilization function (hereinafter referred to as the "OIS function", OIS: Optical Image Stabilization) that optically corrects shake (vibration) generated during shooting to reduce image blur.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the camera module described in Patent Document 1, a guide ball for supporting the lens barrel so as to be movable in the optical axis direction is disposed between the housing and the lens barrel. The housing and the lens barrel are held in a state of being biased against each other via the guide ball. When the housing or the lens barrel is formed of a resin material such as a liquid crystal polymer, there is a risk that the housing or the lens barrel may be deformed by the biasing force, resulting in a decrease in tilt characteristics or a deviation of the optical axis.

[0006] An object of the present invention is to provide an optical element driving device, a camera module, and a camera mounting device that can suppress a decrease in tilt characteristics and a deviation of the optical axis and can move an optical element in the optical axis direction in a stable posture.

Means for Solving the Problems

[0007] The optical element driving device according to the present invention includes: a base, a holder to which an optical element can be attached, a plurality of support portions disposed at rotationally symmetric positions on the outer peripheral surface of the holder and supporting the holder so as to be movable in the optical axis direction with respect to the base, a driving portion that moves the holder in the optical axis direction, The support portion includes: a ball, a ball receiving portion that supports the ball so as to be rollable in the optical axis direction, a biasing portion that presses the ball toward the ball receiving portion, The biasing force of the biasing portion is greater in a second component orthogonal to the radial direction than in a first component parallel to the radial direction passing through the optical axis and the center of the ball in an optical axis orthogonal plane orthogonal to the optical axis direction.

[0008] The camera module according to the present invention includes: the above-described optical element driving device, an imaging unit that captures a subject image using the optical element.

[0009] The camera mounting device according to the present invention includes: A camera-mounted device that is an information device or a transportation device, comprises the above camera module.

Advantages of the Invention

[0010] According to the present invention, it is possible to suppress a decrease in tilt characteristics and a deviation of the optical axis, and the optical element can be moved in the optical axis direction in a stable posture.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Embodiments for Carrying Out the Invention

[0012] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0013] <Smartphone> FIG. 1A and FIG. 1B are diagrams showing a smartphone M (an example of a camera-equipped device) equipped with a camera module A according to an embodiment of the present invention. FIG. 1A is a front view of the smartphone M, and FIG. 1B is a rear view of the smartphone M.

[0014] The smartphone M has a dual camera consisting of two rear cameras OC1 and OC2. In the present embodiment, the camera module A is applied to the rear cameras OC1 and OC2.

[0015] <Camera module> FIG. 2 is an external perspective view of the camera module A. In the present embodiment, an orthogonal coordinate system (X, Y, Z) is used for explanation. The same orthogonal coordinate system (X, Y, Z) is also shown in the figures described later.

[0016] The camera module A is mounted such that, for example, when actual shooting is performed with the smartphone M, the X-axis direction is the vertical direction (or the horizontal direction), the Y-axis direction is the horizontal direction (or the vertical direction), and the Z-axis direction is the front-rear direction. That is, the Z-axis direction is the optical axis direction, the upper side (+Z side) in the figure is the light-receiving side in the optical axis direction, and the lower side (-Z side) is the imaging side in the optical axis direction. Also, the X-axis direction and the Y-axis direction orthogonal to the Z-axis are referred to as the "direction orthogonal to the optical axis", and the XY plane is referred to as the "plane orthogonal to the optical axis". Note that the optical axis direction may be rephrased as the optical path direction or the focus direction (the direction for adjusting the focus) according to the type of optical element. Also, among all directions in the plane orthogonal to the optical axis, the direction passing through the optical axis is referred to as the "radial direction".

[0017] The camera module A has an AF function and can automatically perform focusing when shooting a subject. Note that the camera module A may be configured to have an image stabilization function (hereinafter referred to as the "OIS function", OIS: Optical Image Stabilization) and optically correct shake (vibration) generated during shooting so as to be able to shoot an image without image blur.

[0018] As shown in FIG. 2, the camera module A includes an optical element driving device 1, a lens unit 2, an imaging unit 3, etc. The optical element driving device 1 is a driving device that realizes an AF function. The lens unit 2 is formed by accommodating lenses in, for example, a cylindrical lens barrel. The imaging unit 3 images the subject image formed by the lens unit 2. That is, the optical element driving device 1 is a so-called lens driving device that drives the lens unit 2 as an optical element.

[0019] The optical element driving device 1 of the present embodiment is designed in consideration of being mounted on the above-described camera module A, etc., and has a configuration in which the length in the Z-axis direction is shorter than the lengths in the X-axis direction and the Y-axis direction, that is, a configuration in which the height along the Z-axis direction is made low-profile.

[0020] The imaging unit 3 is disposed on the imaging side in the Z-axis direction of the optical element driving device 1. The imaging unit 3 has, for example, an image sensor substrate 301, an imaging element 302 mounted on the image sensor substrate 301, and a module control unit 303.

[0021] The image sensor substrate 301 is, for example, a flexible printed circuit board (FPC). The image sensor substrate 301 is configured to be able to transmit the imaging signal obtained by the imaging element 302 to a control device (not shown) of the smartphone M. The control device of the smartphone M includes an image processing unit (not shown) that processes the received imaging signal. The optical element driving device 1 is mounted on the image sensor substrate 301 and is mechanically and electrically connected to the image sensor substrate 301.

[0022] The imaging element 302 is formed by, for example, a CCD (charge-coupled device) type image sensor, a CMOS (complementary metal oxide semiconductor) type image sensor, etc., and images the subject image formed by the lens unit 2.

[0023] The module control unit 303 is composed of, for example, a control IC. The module control unit 303 performs drive control of the optical element drive device 1. The module control unit 303 may be provided on the image sensor substrate 301, or may be provided on a camera-mounted device (in this embodiment, the smartphone M) on which the camera module A is mounted.

[0024] <Optical element drive device> FIG. 3 is an external perspective view of the optical element drive device 1. FIG. 4 is an exploded perspective view of the optical element drive device 1 as viewed from the light-receiving side in the optical axis direction. FIG. 5 is a plan view of the optical element drive device 1 as viewed from the light-receiving side in the optical axis direction. In FIG. 3, the state where the cover 13 is removed is shown. In FIG. 4, the cover 13 is omitted.

[0025] As shown in FIGS. 3 to 5, the optical element drive device 1 includes a holder 11, a base 12, a cover 13, a drive unit 20, a support unit 30, and the like.

[0026] The cover 13 is an exterior body of the optical element drive device 1. The cover 13 covers the outside of the drive device main body (reference numeral omitted). The cover 13 is a covered rectangular tube having a substantially rectangular shape in a plan view as viewed from the positive side in the Z-axis direction (light-receiving side in the optical axis direction). The plan view shape of the cover 13 is, for example, a square. That is, the optical element drive device 1 has a rectangular shape extending in the X-axis direction and the Y-axis direction in a plan view as viewed from the positive side in the Z-axis direction. In the following description, "plan view" means a plan view as viewed from the positive side in the Z-axis direction.

[0027] The cover 13 has a substantially circular opening 131 on the surface (upper surface) on the light-receiving side in the optical axis direction. The lens unit 2 (see FIG. 2) faces the outside through the opening 131 of the cover 13. The lens unit 2 may be arranged so as to protrude on the light-receiving side in the Z-axis direction from the opening surface of the cover 13. The cover 13 is fixed to the base 12 of the optical element drive device 1 by adhesion, for example.

[0028] Note that the cover 13 may be formed of, for example, a magnetic material and may have a shielding function of blocking the incidence of external electromagnetic waves or the radiation of electromagnetic waves to the outside.

[0029] The holder 11 is configured to be able to attach the lens unit 2 (see FIG. 2). The holder 11 is a movable body that holds the lens unit 2 and moves in the Z-axis direction during focusing. The holder 11 is connected to the base 12 via the support portion 30. The holder 11 is formed of, for example, polyarylate (PAR), a PAR alloy in which a plurality of resin materials including PAR are mixed, a liquid crystal polymer, or the like.

[0030] The holder 11 has, for example, a substantially octagonal shape in plan view. Specifically, the holder 11 has short side portions corresponding to the four corners of the optical element driving device 1 and long side portions connecting the short side portions. Further, the holder 11 has a cylindrical opening 111 at the central portion. The lens unit 2 (see FIG. 2) is fixed to the inner peripheral surface of the opening 111, for example, by adhesion.

[0031] The base 12 is a fixed body that supports the holder 11 so as to be movable in the Z-axis direction. The base 12 has a rectangular shape in plan view, and a circular opening 121 is formed at the center. In the camera module A, an image sensor substrate 301 on which the imaging element 302 is mounted is disposed on the negative side in the Z-axis direction (the imaging side in the optical axis direction) of the base 12.

[0032] The base 12 is formed of, for example, a molding material made of polyarylate (PAR), a PAR alloy (for example, PAR / PC) in which a plurality of resin materials including PAR are mixed, or a liquid crystal polymer.

[0033] For example, a wiring fitting (not shown) is embedded in the base 12 by insert molding. The wiring fitting is electrically connected to the wiring pattern of the image sensor substrate 301.

[0034] The drive unit 20 is an actuator that moves the holder 11 in the optical axis direction with respect to the base 12. In the present embodiment, an actuator of a VCM (voice coil motor) system is applied to the drive unit 20. Specifically, the drive unit 20 has a magnet 21 and a coil 22 that constitute a VCM.

[0035] In this embodiment, a magnet 21 is attached to the holder 11 side which is a movable body, and a coil 22 is attached to the base 12 side which is a fixed body. That is, a moving magnet type VCM is adopted.

[0036] Specifically, the magnet 21 is composed of a rectangular parallelepiped-shaped two-sided two-pole magnet. The magnet 21 is fitted into recesses provided on two side surfaces (two side surfaces corresponding to the long sides) facing the X-axis direction of the holder 11, and is fixed, for example, by adhesion.

[0037] The coil 22 is a flat coil that is energized during focusing. The coil 22 is fixed so as to face the magnet 21. Specifically, two coils 22 are arranged on a coil substrate 23. The coil substrate 23 is a flexible printed circuit board having a wiring pattern (not shown) for supplying power to the coil 22. The wiring pattern of the coil substrate 23 is electrically connected to a wiring fitting (not shown) arranged on the base 12.

[0038] The coil substrate 23 is wound around a ball receiving portion 32 erected on the base 12 and fixed to the base 12 so that the magnet 21 and the coil 22 face each other in the X-axis direction, for example. The sizes and arrangements of the magnet 21 and the coil 22 are set such that the magnetic field radiated from the magnet 21 in the X-axis direction intersects the coil 22 and returns to the magnet 21.

[0039] Note that the configuration of the drive unit 20 described above (for example, the number, shape, and arrangement of the magnet 21 and the coil 22, etc.) is an example, and other configurations may be applied. For example, when the drive unit 20 is a VCM type actuator, a so-called moving coil type VCM in which the coil 22 is attached to the holder 11 side and the magnet 21 is attached to the base 12 side may be adopted. Also, for example, an ultrasonic motor type actuator can be applied to the drive unit 20.

[0040] The support portion 30 supports the holder 11 so as to be movable in the Z-axis direction (optical axis direction) with respect to the base 12. A plurality of support portions 30 are arranged at rotationally symmetric positions on the outer peripheral surface of the holder 11. In the present embodiment, the support portions 30 are arranged at four corner portions of a rectangular shape, that is, at positions that are rotationally symmetric by 90° about the optical axis. By arranging the support portions 30 at rotationally symmetric positions about the optical axis, the holder 11 is supported in a stable posture, so that a decrease in tilt characteristics and a deviation of the optical axis can be suppressed.

[0041] Note that the support portions 30 may be arranged at a plurality of rotationally symmetric positions about the optical axis. For example, they may be arranged at three positions that are rotationally symmetric by 120°.

[0042] Each support portion 30 includes a ball 31, a ball receiving portion 32, and a biasing portion 33. The ball 31 is a rolling element that can roll following the movement of the holder 11 in the Z-axis direction. The ball receiving portion 32 supports the ball 31 so as to be rollable in the Z-axis direction. The biasing portion 33 presses the ball 31 toward the ball receiving portion 32.

[0043] In the present embodiment, each support portion 30 has a first ball support portion 30A and a second ball support portion 30B.

[0044] The ball receiving portion 32 is fixed to the base 12. The biasing portion 33 is fixed to the holder 11. In the present embodiment, the base 12 and the ball receiving portion 32 are integrally formed of one member. More specifically, two ball receiving portions 32 are erected at each of the four corner portions of the base 12. Further, a biasing portion 33 is provided for each ball receiving portion 32. The ball 31 is accommodated in the accommodation space formed by the ball receiving portion 32 and the biasing portion 33.

[0045] The biasing direction of the biasing portion 33 intersects with the radial direction passing through the optical axis O and the center of the ball 31 in the XY plane (see Fig. 6). Compared with the case where the biasing direction of the biasing portion 33 coincides with the radial direction, the biasing force acting on the holder 11 via the ball 31 becomes smaller, so that the deformation of the holder 11 due to the biasing force can be suppressed.

[0046] Fig. 6 is a plan view showing an enlarged view of one support portion 30. Fig. 7 is a schematic view showing the biasing force in the support portion 30. Fig. 8 is a perspective view of the support portion 30.

[0047] As shown in Figs. 6 - 8, the first ball support portion 30A has a set of balls 31A, a ball receiving portion 32A, and a biasing portion 33A. Similarly, the second ball support portion 30B has a set of balls 31B, a ball receiving portion 32B, and a biasing portion 33B.

[0048] In the embodiment, a spacer 34A is interposed between the two balls 31A, and a spacer 34B is interposed between the two balls 31B. Further, the support portion 30 has stopper portions 36, 37.

[0049] The biasing direction of the biasing portion 33A intersects with the radial direction D1 passing through the center of the ball 31A in the XY plane. When the biasing force F1 of the biasing portion 33A is decomposed into a first component F11 parallel to the radial direction D1 and a second component F12 orthogonal to the radial direction, the second component F12 is larger than the first component F11. That is, the biasing direction of the biasing portion 33A is set such that F11 < F12.

[0050] Similarly, the biasing direction of the biasing portion 33B intersects with the radial direction D2 passing through the center of the ball 31B in the XY plane. When the biasing force F2 of the biasing portion 33B is decomposed into a first component F21 parallel to the radial direction D2 and a second component F22 orthogonal to the radial direction, the second component F22 is larger than the first component F21. That is, the biasing direction of the biasing portion 33B is set such that F21 < F22.

[0051] Further, the first ball support portion 30A and the second ball support portion 30B have a symmetrical structure with respect to the midpoint of the line segment connecting the centers of the balls 31A and 31B and the radial direction D3 passing through the optical axis O. That is, the direction of the biasing force F1 in the first ball support portion 30A and the direction of the biasing force F2 in the second ball support portion 30B are symmetrical with respect to the radial direction D3. Also, the components of the biasing forces F1 and F2 orthogonal to the radial direction D3 are in opposite directions.

[0052] Hereinafter, when the configurations of the first ball support portion 30A and the second ball support portion 30B are not distinguished, they are simply referred to as "ball 31", "ball receiving portion 32", "biasing portion 33", and "spacer 34".

[0053] The ball receiving portion 32 is a columnar body having a groove portion 321. The groove portion 321 extends along the Z-axis direction and has, for example, a V-shape in plan view. Specifically, the groove portion 321 of the ball receiving portion 32 has an L-shape (an example of a V-shape) in plan view. The ball receiving portion 32 is disposed on the base 12 such that the two surfaces of the groove portion 321 are along the X-axis direction and the Y-axis direction, respectively.

[0054] The biasing portion 33 is a leaf spring formed of a plate-like body. The biasing portion 33 preferably has a groove portion 331. The groove portion 331 extends along the Z-axis direction and has, for example, a V-shape in plan view. Specifically, the groove portion 331 of the biasing portion 33 has an L-shape (an example of a V-shape) in plan view. The biasing portion 33 is attached to the holder 11 such that the two surfaces of the groove portion 331 are along the X-axis direction and the Y-axis direction, respectively.

[0055] In the present embodiment, the biasing portion 33A of the first ball support portion 30A and the biasing portion 33B of the second ball support portion 30B are integrally formed on one member. Specifically, the biasing portions 33A and 33B are part of a sheet metal component formed by bending a single sheet of plate material, and are connected by a U-shaped connecting portion 35 in plan view. For example, the connecting portion 35 is bolted to the short side portion of the holder 11, thereby being fixed to the holder 11.

[0056] In the sheet metal part formed with the biasing portions 33A and 33B, the separation angle (for example, the separation angle of the vertices of the V-shaped groove portions 321 and 331) of the biasing portions 33A and 33B is set wider compared to the state after the support portion 30 is assembled. That is, in the state where the support portion 30 is assembled, the biasing portions 33A and 33B exert a biasing force in a direction of separating from each other.

[0057] The groove portion 321 of the ball receiving portion 32 and the groove portion 331 of the biasing portion 33 form a housing space having a substantially shape in plan view. Two balls 31 and a spacer 34 are housed in this housing space. The balls 31 are sandwiched in a biased state by the groove portion 321 of the ball receiving portion 32 and the groove portion 331 of the biasing portion 33. In the present embodiment, the balls 31 are supported at four points by the V-shaped groove portion 321 and the V-shaped biasing portion 33.

[0058] Also, the lengths of the two balls 31 and the spacer 34 in the Z-axis direction are smaller than the length of the housing space formed by the ball receiving portion 32 and the biasing portion 33 in the Z-axis direction. That is, the balls 31 and the spacer 34 are housed in the housing space so as to be movable in the Z-axis direction.

[0059] The stopper portions 36 and 37 prevent the balls 31 from dropping off in the optical axis direction. The stopper portions 36 and 37 are provided so as to close the positive side (light receiving side in the optical axis direction) and the negative side (image forming side in the optical axis direction) in the Z-axis direction of the housing space formed by the groove portion 321 of the ball receiving portion 32 and the groove portion 331 of the biasing portion 33, respectively. In the present embodiment, the stopper portions 36 and 37 are continuously provided at both ends of the biasing portion 33 in the Z-axis direction. Note that the stopper portions 36 and 37 may be arranged on the positive side (light receiving side in the optical axis direction) and the negative side (image forming side in the optical axis direction) of the balls 31, and do not necessarily have to be arranged at both ends of the biasing portion 33 in the Z-axis direction.

[0060] The spacer 34 keeps the separation distance between the two balls 31 constant. The spacer 34 has, for example, a columnar body portion 341 and seat surface portions 342 disposed at both ends of the body portion 341. The seat surface portions 342 are in contact with the balls 31. The spacer 34 moves together with the balls 31 when the balls 31 move in the optical axis direction.

[0061] Preferably, the outer shape of the seat surface portion 342 is smaller than the outer shape of the ball 31 in a plan view. When the outer shape of the seat surface portion 342 is the same as the outer shape of the ball 31, the seat surface portion 342 contacts the ball receiving portion 32 in the same manner as the ball 31. On the other hand, when the outer shape of the seat surface portion 342 is small, the contact area between the seat surface portion 342 and the ball receiving portion 32 becomes small. Therefore, the frictional force between the seat surface portion 342 and the ball receiving portion 32 is reduced, and the ball 31 can be smoothly moved in the optical axis direction.

[0062] Note that the outer shape of the body portion 341 may be equivalent to the outer shape of the seat surface portion 342, or may be smaller than the outer shape of the seat surface portion 342. When the outer shape of the body portion 341 is made smaller than the outer shape of the seat surface portion 342, the weight and cost of the component can be reduced.

[0063] When performing autofocus in the optical element driving device 1, the coil 22 is energized. Power supply to the coil 22 is performed via the coil substrate 23. When the coil 22 is energized, a Lorentz force is generated in the coil 22 due to the interaction between the magnetic field of the magnet 21 and the current flowing through the coil 22. The direction of the Lorentz force is a direction (Z-axis direction) orthogonal to the direction of the magnetic field (X-axis direction) by the magnet 21 and the direction of the current (Y-axis direction) flowing through the coil 22. Since the coil 22 is fixed, a reaction force acts on the magnet 21. This reaction force becomes the driving force of the voice coil motor, and the holder 11 on which the magnet 21 is disposed moves in the optical axis direction, and autofocus is performed.

[0064] At this time, since the biasing portion 33 is fixed to the holder 11, as the holder 11 moves in the optical axis direction, the ball 31 mainly rolls. The holder 11 can move in a stable posture in the optical axis direction by the support portion 30 using the ball 31. Note that the ball 31 may slide as the holder 11 moves in the optical axis direction.

[0065] [Modification Example] FIG. 7 is a diagram showing another example of the support portion 30.

[0066] In the embodiment, in the support portion 30, two balls 31 are arranged in the accommodation space formed between the ball receiving portion 32 and the biasing portion 33, and the two balls 31 are separated by a spacer 34. In this case, depending on the posture of the optical element driving device 1, the ball 31 may move away from the spacer 34 and roll or slide in the accommodation space, and the separation distance between the two balls 31 may vary.

[0067] On the other hand, in the modification example, instead of the spacer 34, a retainer 38 is used to hold the two balls 31 in a separated state. The retainer 38 is a columnar member and has ball accommodation portions 381 for accommodating each of the two balls 31. The ball accommodation portions 381 are provided to penetrate the main body of the retainer 38 and accommodate the balls 31 so that the contact points with the biasing portion 33 are exposed. By using the retainer 38, in the accommodation space formed by the ball receiving portion 32 and the biasing portion 33, the separation distance between the two balls 31 is always kept constant. Thereby, the movement of the holder 11 in the optical axis direction is stabilized.

[0068] Note that instead of the spacer 34 or the retainer 38, a ball having a smaller diameter than the ball 31 may be interposed between the two balls 31 to maintain the separation distance between the two balls 31.

[0069] As described above, the optical element driving device 1, the camera module A, and the smartphone M (camera-mounted device) according to the present embodiment have the following characteristic matters alone or in appropriate combinations.

[0070] That is, the optical element driving device 1 includes a base 12, a holder 11 to which a lens unit 2 (optical element) can be attached, a plurality of support portions 30 disposed at rotationally symmetric positions on the outer peripheral surface of the holder 11 and supporting the holder 11 so as to be movable in the optical axis direction with respect to the base 12, and a driving portion 20 that moves the holder 11 in the optical axis direction. The support portion 30 has a ball 31, a ball receiving portion 32 that rotatably supports the ball 31 in the optical axis direction, and a biasing portion 33 that presses the ball 31 toward the ball receiving portion 32. The biasing force F1 of the biasing portion 33A is greater in the second component F12 orthogonal to the radial direction D2 than in the first component F11 parallel to the radial direction D1 passing through the optical axis O and the center of the ball 31A in the optical axis orthogonal plane orthogonal to the optical axis direction. Similarly, the biasing force F2 of the biasing portion 33B is greater in the second component F22 orthogonal to the radial direction D2 than in the first component F21 parallel to the radial direction D2 passing through the optical axis O and the center of the ball 31B in the optical axis orthogonal plane orthogonal to the optical axis direction.

[0071] According to the optical element driving device 1, since the support portions 30 are arranged at rotationally symmetric positions centered on the optical axis and the holder 11 is supported in a stable posture, it is possible to suppress a decrease in tilt characteristics and a deviation of the optical axis. Further, compared with the case where the biasing direction of the biasing portion 33 coincides with the radial direction, the biasing forces (the first components F11 and F21 of the biasing forces F1 and F2) acting on the holder 11 are reduced, so that deformation of the holder 11 due to the biasing force can be suppressed. Therefore, the effect of suppressing a decrease in tilt characteristics and a deviation of the optical axis is enhanced, and the lens unit 2 can be moved in the optical axis direction in a stable posture.

[0072] In the optical element driving device 1, the support portion 30 has a first ball support portion 30A and a second ball support portion 30B. The first ball support portion 30A and the second ball support portion 30B each have a set of balls 31, a ball receiving portion 32, and a biasing portion 33. The first ball support portion 30A and the second ball support portion 30B are symmetric with respect to the midpoint between the two balls 31A and 31B and the radial direction passing through the optical axis O. Since the components of the biasing forces F1 and F2 of the biasing portions 33A and 33B orthogonal to the radial direction D3 are in opposite directions, the force for rotating the holder 11 around the optical axis is canceled out, so that the posture of the holder 11 can be stabilized.

[0073] In the optical element driving device 1, the biasing portion 33A of the first ball support portion 30A and the biasing portion 33B of the second ball support portion 30B are integrally formed on one member. Thereby, the number of parts can be reduced, the assembly work can be facilitated, and the biasing forces of the biasing portions 33A and 33B can be easily controlled.

[0074] In the optical element driving device 1, the biasing portion 33 is constituted by a leaf spring. Thereby, the biasing portion 33 can be realized with a simple structure.

[0075] In the optical element driving device 1, the biasing portion 33 and the ball receiving portion 32 each have V-shaped groove portions 331 and 321 and are in contact with the ball 31 at two points. Thereby, the ball 31 can be held in a stable posture and can roll or slide smoothly in the optical axis direction.

[0076] In the optical element driving device 1, the biasing portion 33 is attached to the holder 11, and the ball receiving portion 32 is attached to the base 12. Thereby, the effect of suppressing the deformation of the holder 11 can be enhanced.

[0077] In the optical element driving device 1, the ball receiving portion 32 and the base 12 are integrally formed on one member. Thereby, the number of parts can be reduced and the cost can be reduced.

[0078] In the optical element driving device 1, the biasing portion 33 has stopper portions 36 and 37 that prevent the ball 31 from dropping off in the optical axis direction. Thereby, it is possible to reliably prevent the ball 31 from dropping off, and the reliability of the optical element driving device 1 is improved.

[0079] In the optical element driving device 1, the support portion 30 has two balls 31 arranged side by side in the optical axis direction and a spacer 34 interposed between the two balls 31. Since the two balls 31 and the spacer 34 can be individually attached to the accommodation space formed by the ball receiving portion 32 and the biasing portion 33, various assembly methods can be applied, and workability is improved.

[0080] In the optical element driving device 1, the spacer 34 has a columnar body portion 341 and seat surface portions 342 disposed at both ends of the body portion 341 and contacting the respective two balls 31. With the seat surface portion 342, the ball 31 can be rolled or slid while being held in a stable posture.

[0081] In the optical element driving device 1, the outer shape of the seat surface portion 342 is smaller than the outer shape of the ball 31 in a plan view seen from the optical axis direction. Since the friction between the seat surface portion 342 and the ball receiving portion 32 or the biasing portion 33 is reduced, the ball 31 can be smoothly moved in the optical axis direction.

[0082] Also, in the optical element driving device 1 according to the modification, the support portion 30 has two balls 31 arranged side by side in the optical axis direction and a retainer 38 having two ball accommodation portions 381 that accommodate the respective two balls 31 such that the contact points with the biasing portion 33 are exposed. In the accommodation space formed by the ball receiving portion 32 and the biasing portion 33, the separation distance between the two balls 31 is always kept constant, so the movement of the holder 11 in the optical axis direction is stabilized.

[0083] As described above, the invention made by the present inventor has been specifically described based on the embodiments. However, the present invention is not limited to the above embodiments, and can be modified without departing from the gist thereof.

[0084] For example, in the above embodiment, the smartphone M was taken as an example for explanation. However, the present invention can be applied to a camera-equipped device having a camera module and an image processing unit that processes image information obtained by the camera module. The camera-equipped device includes information devices and transportation devices. Information devices include, for example, a mobile phone with a camera, a notebook computer, a tablet terminal, a portable game machine, a web camera, a vehicle-mounted device with a camera (e.g., a rear monitor device, a drive recorder device), and the like. In addition, transportation devices include, for example, an automobile and a drone (unmanned aerial vehicle), and the like.

[0085] FIGS. 8A and 8B are diagrams showing an automobile V as a camera-equipped device equipped with an in-vehicle camera module VC (Vehicle Camera). FIG. 8A is a front view of the automobile V, and FIG. 8B is a rear perspective view of the automobile V. The automobile V is equipped with the camera module A described in the above embodiment as the in-vehicle camera module VC. As shown in FIGS. 8A and 8B, the in-vehicle camera module VC is attached to the windshield facing forward or to the rear gate facing backward, for example. This in-vehicle camera module VC is used for a rear monitor, a drive recorder, collision avoidance control, automatic driving control, and the like.

[0086] In addition, in the above embodiment, the optical element driving device 1 that drives the lens unit 2 as an optical element was described. However, the optical element to be driven may be an optical element other than a lens, such as a mirror or a prism. Further, the present invention can also be applied to an optical element driving device that drives an imaging element as an optical element, for example.

[0087] In addition, in the above embodiment, the optical element driving device 1 has an AF function. However, it may have a function of moving the lens unit 2 in the Z-axis direction, such as a zoom function, in addition to the AF function.

[0088] The embodiments disclosed this time should be considered illustrative in all respects and not restrictive. The scope of the present invention is shown not by the above description but by the claims, and it is intended that all modifications within the meaning and scope equivalent to the claims are included.

Explanation of Signs

[0089] 1 Optical element driving device 2 Lens unit 11 Holder 12 Base 20 Driving unit 30 Support unit 31 Ball 32 Ball receiving part 33 Biasing unit 34 Spacer 36, 37 Stopper parts 38 Retainer M Smartphone A Camera module

Claims

1. A base, a holder to which an optical element can be attached, a plurality of support portions disposed at rotationally symmetric positions on the outer peripheral surface of the holder and supporting the holder movably in the optical axis direction with respect to the base, a drive portion that moves the holder in the optical axis direction, and comprising: The support portion a ball, a ball receiving portion that rotatably supports the ball in the optical axis direction, a biasing portion that presses the ball toward the ball receiving portion, and having: The biasing force of the biasing portion is greater in a second component orthogonal to the radial direction than in a first component parallel to the radial direction passing through the optical axis and the center of the ball in an optical axis orthogonal plane orthogonal to the optical axis direction. An optical element driving device.

2. The support portion has a first ball support portion and a second ball support portion, The first ball support portion and the second ball support portion each have a set of the ball, the ball receiving portion, and the biasing portion, The first ball support portion and the second ball support portion are symmetric with respect to a radial direction passing through the midpoint between the two balls and the optical axis. The optical element driving device according to claim 1.

3. The biasing portion of the first ball support portion and the biasing portion of the second ball support portion are integrally formed on one member. The optical element driving device according to claim 2.

4. The biasing portion is constituted by a leaf spring. The optical element driving device according to claim 1 or 2.

5. The biasing portion and the ball receiving portion each have a V-shaped groove portion and are in contact with the ball at two points. The optical element driving device according to claim 4.

6. The biasing portion is attached to the holder, The ball receiving portion is attached to the base. The optical element driving device according to claim 1 or 2.

7. The ball receiving portion and the base are integrally formed on one member. The optical element driving device according to claim 6.

8. The support portion has a stopper portion that prevents the ball from dropping off in the optical axis direction. The optical element driving device according to claim 1 or 2.

9. The support portion two balls arranged side by side in the optical axis direction, a spacer interposed between the two balls, and having: The optical element driving device according to claim 1 or 2.

10. The spacer a columnar body portion, seat surface portions disposed at both ends of the body portion and in contact with each of the two balls, and having: The optical element driving device according to claim 9.

11. The outer shape of the seat surface portion is smaller than the outer shape of the ball in a plan view seen from the optical axis direction. The optical element driving device according to claim 10.

12. The support portion Two of the balls arranged side by side in the optical axis direction, A retainer having two ball housing portions that house each of the two balls so that the contact points with the biasing portion are exposed, And having The optical element driving device according to claim 1 or 2.

13. The optical element driving device according to claim 1, And an imaging unit that images a subject image using the optical element. Camera module.

14. A camera-mounted device that is an information device or a transportation device, Comprising the camera module according to claim 13. Camera-mounted device.

Images