Rotary drive device

Abstract

To provide a rotation drive device capable of achieving miniaturization and reduced height.SOLUTION: A rotation drive device comprises: a fixed part which has a peripheral section that has a shape that surrounds a circular opening and in which wiring is arranged, and in which a recess opening upward and recessed downward is provided in an arc shape along a circumferential direction in the peripheral section; a ring-shaped rotating body which is disposed on the peripheral section of the fixed part, and has an annular portion extending along the circumferential direction and a protruding portion provided to protrude downward from the annular portion at a position corresponding to the recess; a sliding support part that supports sliding of the rotating body relative to the fixed part at the position where the recess and the protruding portion are provided; and a drive part which has a fixed portion fixed to the fixed part and a movable portion fixed to the rotating body, and in which the fixed portion receives power via the wiring, and the movable portion transmits driving force to the rotating body to rotate the rotating body.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to a rotary drive device.

Background Art

[0002] Generally, a mobile terminal such as a smartphone is equipped with a small camera module. Such a camera module has an autofocus function (hereinafter referred to as "AF function", AF: Auto Focus) that automatically focuses when shooting a subject and an optical image stabilization function (hereinafter referred to as "OIS function", OIS: Optical Image Stabilization) that optically corrects shake (vibration) generated during shooting to reduce image blur. A lens drive device having these functions is applied (for example, Patent Document 1).

[0003] A lens drive device having an AF function and an OIS function includes an autofocus drive unit (hereinafter referred to as "AF drive unit") for moving the lens unit in the optical axis direction and an optical image stabilization drive unit (hereinafter referred to as "OIS drive unit") for swinging the lens unit in a plane orthogonal to the optical axis direction. In Patent Document 1, a voice coil motor (VCM) is applied to the AF drive unit and the OIS drive unit.

[0004] In recent years, the practical application of a camera module having a plurality (typically two) of lens drive devices (so-called dual camera) has been promoted. The dual camera has various possibilities depending on the usage scene, such as being able to simultaneously capture two images with different focal lengths or being able to simultaneously capture a still image and a moving image.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

[0006] Patent Document 2 discloses a lens drive device that applies ultrasonic motors to the AF drive unit and OIS drive unit. The lens drive device disclosed in Patent Document 2 is magnetless and can reduce the influence of external magnets, but its structure is complex, making it difficult to miniaturize and reduce its height.

[0007] The objective of the present invention is to provide a rotary drive device that can be miniaturized and have a low profile. [Means for solving the problem]

[0008] One aspect of the rotary drive device according to the present invention is: A fixing portion having a shape surrounding a circular opening and an outer periphery on which wiring is arranged, wherein a recess opening upward and concave downward is provided in an arc shape along the circumferential direction on the outer periphery, A ring-shaped rotating body disposed on the outer circumference of the fixed part, having an annular portion extending along the circumferential direction and a protruding portion that protrudes downward from the annular portion at a position corresponding to the recess, A sliding support portion that supports the sliding of the rotating body relative to the fixed portion at the position where the recess and the protrusion are provided, The system includes a fixed portion fixed to the fixed part and a movable portion fixed to the rotating body, the fixed portion receiving power via the wiring, and the movable portion transmitting driving force to the rotating body, thereby rotating the rotating body Along the circumferential direction A drive unit that causes rotational motion, It has. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a rotary drive device that can be miniaturized and have a low profile. [Brief explanation of the drawing]

[0010] [Figure 1]FIG. 1A and FIG. 1B are diagrams showing a smartphone equipped with a camera module according to an embodiment of the present invention. [Figure 2] FIG. 2 is an external perspective view of the camera module. [Figure 3] FIG. 3A and FIG. 3B are external perspective views of the lens driving device. [Figure 4] FIG. 4 is an exploded perspective view of the lens driving device. [Figure 5] FIG. 5 is an exploded perspective view of the lens driving device. [Figure 6] FIG. 6A and FIG. 6B are perspective views of the first OIS driving unit. [Figure 7] FIG. 7 is an exploded perspective view of the OIS movable unit. [Figure 8] FIG. 8 is an exploded perspective view of the OIS movable unit. [Figure 9] FIG. 9 is a perspective view of the AF driving unit. [Figure 10] FIG. 10A and FIG. 10B are diagrams showing the behavior of the lens holder as the rotation spacer rotates. [Figure 11] FIG. 11A and FIG. 11B are diagrams showing an automobile as a camera mounting device equipped with an in-vehicle camera module.

Embodiments for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

[0012] FIG. 1A and FIG. 1B are diagrams showing a smartphone M (an example of a camera mounting 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.

[0013] The smartphone M has a dual camera composed of two rear cameras OC1 and OC2. In the present embodiment, the camera module A is applied to the rear cameras OC1 and OC2. The camera module A has an AF function and an OIS function, automatically focuses when shooting a subject, and can optically correct shake (vibration) generated during shooting to capture an image without image blur.

[0014] Figure 2 is an external perspective view of the camera module A. Figures 3A and 3B are external perspective views of the lens driving device 1. Figure 3B shows a state where Figure 3A is rotated 180° around the Z axis. As shown in Figures 2, 3A, and 3B, in this embodiment, the description will be made using a rectangular coordinate system (X, Y, Z). The subsequent figures are also shown in the common rectangular coordinate system (X, Y, Z).

[0015] When the camera module A is actually used for shooting, for example, in a smartphone M, it is mounted such that the X direction is the vertical direction (or the horizontal direction), the Y direction is the horizontal direction (or the vertical direction), and the Z direction is the front-rear direction. That is, the Z direction is the optical axis direction, the upper side (+Z side) in the figure is the light-receiving side in the optical axis direction (subject side), and the lower side (-Z side) is the imaging side in the optical axis direction. Also, the X direction and the Y direction are "directions orthogonal to the optical axis" orthogonal to the Z axis, and the XY plane is a "plane orthogonal to the optical axis" orthogonal to the optical axis.

[0016] As shown in Figure 2 and the like, the camera module A includes a lens driving device 1 that realizes an AF function and an OIS function, a lens unit 2 in which lenses are housed in a cylindrical lens barrel, an imaging unit (not shown) that images the subject image formed by the lens unit 2, and a cover 3 that covers the whole.

[0017] The cover 3 is a rectangular covered rectangular cylinder in plan view as viewed from the optical axis direction. In this embodiment, the cover 3 has a square shape in plan view. The cover 3 has a substantially circular opening 3a on the upper surface. The lens unit 2 faces the outside through the opening 3a and is configured to protrude to the light-receiving side beyond the opening surface of the cover 3 as it moves in the optical axis direction. The cover 3 is fixed to the OIS fixing portion 20 (see Figure 4) of the lens driving device 1, for example, by adhesion.

[0018] The imaging unit (not shown) is positioned on the optical axis imaging side of the lens drive device 1. The imaging unit (not shown) includes, for example, an image sensor substrate and an image sensor mounted on the image sensor substrate. The image sensor is composed of, for example, a CCD (charge-coupled device) type image sensor, a CMOS (complementary metal oxide semiconductor) type image sensor, etc. The image sensor captures the subject image formed by the lens unit 2. The lens drive device 1 is mounted on the image sensor substrate (not shown) and is mechanically and electrically connected. The control unit that controls the drive of the lens drive device 1 may be provided on the image sensor substrate, or it may be provided on the camera-mounted device (in this embodiment, a smartphone M) on which the camera module A is mounted.

[0019] Figures 4 and 5 are exploded perspective views of the lens drive device 1. Figure 5 shows Figure 4 rotated 90° around the Z-axis and viewed from below. As shown in Figures 4 and 5, in this embodiment, the lens drive device 1 includes an OIS movable part 10 (second movable part), an OIS fixed part 20 (second fixed part), an OIS drive part 30 (XY direction drive part), and an OIS support part 40 (second support part), etc.

[0020] The OIS movable part 10 is the part that oscillates in a plane orthogonal to the optical axis during shake correction. The OIS movable part 10 includes an AF unit having an AF movable part 11 (first movable part), a first stage 12 (first fixed part), an AF drive unit 13 (Z-direction drive unit), an AF support unit 14 (first support unit), and a rotating spacer 15 (see Figure 7, etc.). The OIS fixing section 20 is the part to which the OIS movable section 10 is connected via the OIS support section 40. The OIS fixing section 20 includes a base 21. The OIS support section 40 supports the OIS movable section 10 in a position separated from the OIS fixed section 20 in the optical axis direction. The OIS support section 40 includes second stages 41X, 41Y, balls 42, 43, and an OIS biasing member 44. The OIS movable part 10 is positioned spaced apart from the OIS fixed part 20 in the optical axis direction and is connected to the OIS fixed part 20 via the OIS support part 40. The OIS movable part 10 and the OIS fixed part 20 are biased toward each other by OIS biasing members 44 located at four locations on the outer circumferential surface of the OIS movable part 10. In this embodiment, the OIS movable part 10 can be precisely oscillated in the XY plane by restricting the direction in which the balls 42 and 43 (11 in total) constituting the OIS support part 40 can roll. The number of balls 42 and 43 constituting the OIS support part 40 can be changed as appropriate.

[0021] The base 21 is a rectangular member in plan view, formed from a molding material consisting of, for example, polyarylate (PAR), a PAR alloy (e.g., PAR / PC) which is a mixture of multiple resin materials including PAR, or liquid crystal polymer (LCP), and has a circular opening 21a in the center. The base 21 has OIS motor fixing portions 21b at two corners, on which the OIS drive unit 30 is positioned. The OIS motor fixing portions 21b are formed to protrude from the main surface of the base 21 toward the light-receiving side in the optical axis direction, and have a shape capable of holding the OIS drive unit 30.

[0022] Although not shown in the diagram, terminal fittings and wiring are arranged on the base 21, for example, by insert molding. A sensor board on which Hall elements 51X and 51Y are mounted is also arranged on the base 21. The wiring includes power supply lines to the AF drive unit 13 (see Figure 7, etc.) and the OIS drive unit 30. The wiring is exposed, for example, from the periphery of the base 21 and is electrically connected to the wiring formed on the sensor substrate and the OIS biasing member 44.

[0023] Furthermore, the base 21 has ball housing sections 21c, 21d, and 21e for accommodating the balls 42. The ball housing section 21c is formed as a circular recess and accommodates the ball 42 interposed between the base 21 and the first stage 12. The ball housing section 21d is formed as a rectangular recess extending in the X direction and accommodates the ball 42 interposed between the base 21 and the second stage 41X. The ball housing section 21e is formed as a rectangular recess extending in the Y direction and accommodates the ball 42 interposed between the base 21 and the second stage 41Y. The sides of the ball housing sections 21d and 21e are tapered, for example, so that the groove width narrows towards the bottom side.

[0024] The sensor substrate (not shown) has wiring (not shown) including power supply lines and signal lines for Hall elements 51X and 51Y. The Hall elements 51X and 51Y are electrically connected to the wiring (not shown) of the base 21 via wiring (not shown) formed on the sensor substrate. In the second stages 41X and 41Y, magnets 52X and 52Y are positioned opposite the Hall elements 51X and 51Y. The XY position detection unit, consisting of the Hall elements 51X and 51Y and the magnets 52X and 52Y, detects the position of the OIS movable part 10 in the X and Y directions.

[0025] The second stages 41X and 41Y are formed, for example, from a liquid crystal polymer and have an overall L-shape. The inner circumferential surfaces of the second stages 41X and 41Y are formed in an arc shape that follows the outer shape of the lens holder 11. The second stages 41X and 41Y are arranged along the X and Y directions, respectively. Furthermore, adjacent parts of the second stages 41X and 41Y are spaced apart by a predetermined interval so that they can move independently of each other. The outer surfaces of the second stages 41X and 41Y are formed with an inward recess, so that the OIS drive units 30X and 30Y are positioned when the lens drive unit 1 is assembled. In this embodiment, the second stages 41X and 41Y are formed in an L-shape as a whole, and the second stages 41X and 41Y are positioned below the thin-walled portion of the first stage 12, thereby reducing the height of the OIS movable part 10.

[0026] The periphery of the second stages 41X and 41Y is provided with engaging pieces 41e and 41f that protrude toward the light-receiving side in the optical axis direction. One end of the OIS power transmission section 33 is fixed to the engaging pieces 41e and 41f. The engaging pieces 41e and 41f are loosely fitted into engaging grooves 12g and 12h provided in the first stage 12. Specifically, the engaging piece 41e and the engaging groove 12g engage to the extent that their opposing surfaces in the Y direction do not come into contact when the first stage 12 moves in the Y direction, and the engaging piece 41f and the engaging groove 12h engage to the extent that their opposing surfaces in the Y direction do not come into contact when the first stage 12 moves in the Y direction. In other words, the second stage 41X does not displace even when the first stage 12 moves in the Y direction, and the second stage 41Y does not displace even when the first stage 12 moves in the X direction.

[0027] Each of the second stages 41X and 41Y has three ball housing sections 41a and 41b on its lower surface (the surface on the optical axis direction imaging side) for housing the ball 42. The ball housing section 41a faces the ball housing sections 21d and 21e of the base 21. The ball housing sections 41a and 41b are formed as oval recesses extending in the X and Y directions, respectively. In addition, the sides of the ball housing sections 41a and 41b are tapered so that the groove width narrows towards the bottom surface. Furthermore, each of the second stages 41X and 41Y has two ball housing sections 41c and 41d on its upper surface (the surface on the light-receiving side in the optical axis direction) for housing the ball 43. The ball housing sections 41c and 41d are formed as oval recesses that extend in the Y and X directions, respectively. The sides of the ball housing sections 41c and 41d are tapered so that the groove width narrows towards the bottom surface.

[0028] The ball 42 is held between the ball housings 21c to 21e of the base 21 and the ball housings 12b of the first stage 12 and 41a and 41b of the second stages 41X and 41Y. In particular, the ball 42 is in multi-point contact with the ball housings 21d and 21e of the base 21 and the ball housings 41a and 41b of the second stages 41X and 41Y. Therefore, the ball 42 rolls stably in the X or Y direction. Furthermore, the ball 43 is held in multi-point contact between the ball housings 41c and 41d of the second stages 41X and 41Y and the lower surface of the first stage 12. Therefore, the ball 43 rolls stably in the X or Y direction.

[0029] The OIS biasing member 44 is composed of, for example, a tension coil spring and connects the OIS movable part 10 and the OIS fixed part 20. In this embodiment, one end of the OIS biasing member 44 is connected to the wiring (not shown) of the base 21, and the other end is connected to the wiring (not shown) of the first stage 12. The OIS biasing member 44 receives the tensile load when the OIS movable part 10 and the OIS fixed part 20 are connected and acts to bring the OIS movable part 10 and the OIS fixed part 20 closer to each other. That is, the OIS movable part 10 is held by the OIS biasing member 44 in a state biased in the optical axis direction (pressed against the base 21) and is able to swing in the XY plane. This makes it possible to hold the OIS movable part 10 in a stable state without rattling. Furthermore, in this embodiment, the OIS biasing member 44 functions as a power supply line to the AF drive unit 13.

[0030] The OIS drive unit 30 is an actuator that moves the OIS movable part 10 in the X and Y directions. Specifically, the OIS drive unit 30 consists of a first OIS drive unit 30X (first XY direction drive unit) that moves the OIS movable part 10 in the X direction, and a second OIS drive unit 30Y (second XY direction drive unit) that moves the OIS movable part 10 in the Y direction. The first OIS drive unit 30X is fixed to the OIS motor fixing portion 21b of the base 21 so as to extend along the X direction. The second OIS drive unit 30Y is fixed to the OIS motor fixing portion 21b of the base 21 so as to extend along the Y direction. That is, the first OIS drive unit 30X and the second OIS drive unit 30Y are arranged along mutually orthogonal sides.

[0031] The configuration of the OIS drive unit 30 is shown in Figures 6A and 6B. Figure 6A shows the assembled components of the OIS drive unit 30, and Figure 6B shows the disassembled components of the OIS drive unit 30. Although Figures 6A and 6B show the second OIS drive unit 30Y, the main configuration of the first OIS drive unit 30X is the same, so they are treated as diagrams showing the OIS drive unit 30.

[0032] As shown in Figures 6A and 6B, the OIS drive unit 30 includes an OIS resonant unit 31, an OIS piezoelectric element 32, an OIS electrode (not shown), and an OIS power transmission unit 33. The OIS resonant unit 31, the OIS piezoelectric element 32, and the OIS electrode (not shown) constitute an ultrasonic motor, and the driving force of the ultrasonic motor is transmitted to the second stages 41X and 41Y via the OIS power transmission unit 33.

[0033] The OIS piezoelectric element 32 is, for example, a plate-shaped element made of a ceramic material, and generates vibrations when a high-frequency voltage is applied. The OIS electrode (not shown) sandwiches the OIS resonant section 31 and the OIS piezoelectric element 32, and applies a voltage to the OIS piezoelectric element 32. The OIS electrode is electrically connected, for example, to the wiring (not shown) of the base 21.

[0034] The OIS resonant section 31 is made of a conductive material and resonates with the vibration of the OIS piezoelectric element 32, converting the vibrational motion into linear motion. In this embodiment, the OIS resonant section 31 has a substantially rectangular body portion 31a sandwiched between the OIS piezoelectric element 32, two arm portions 31b extending from the upper and lower parts of the body portion 31a, a protruding portion 31c protruding from the central part of the body portion 31a, and an energizing portion 31d extending from the central part of the body portion 31a on the opposite side from the protruding portion 31c. The energizing portion 31d is electrically connected, for example, to the wiring of the base 21. The two arm portions 31b have a symmetrical shape, and their respective free ends abut against the OIS power transmission portion 33, resonating with the vibration of the OIS piezoelectric element 32 and deforming symmetrically.

[0035] An OIS piezoelectric element 32 is attached to the body portion 31a of the OIS resonant portion 31 from the thickness direction and sandwiched by OIS electrodes (not shown), thereby electrically connecting them to each other. For example, when one end of the power supply path is connected to the OIS electrodes and the other end is connected to the energized portion 31d of the OIS resonant portion 31, a voltage is applied to the OIS piezoelectric element 32, causing vibration to occur.

[0036] The OIS resonant section 31 has at least two resonant frequencies and deforms in a different manner for each resonant frequency. In other words, the overall shape of the OIS resonant section 31 is set so that it deforms in a different manner for two resonant frequencies. The different behaviors are one that moves the OIS power transmission section 33 forward in the X or Y direction, and the other that moves it backward.

[0037] The OIS power transmission section 33 is a chucking guide extending in one direction, with one end connected to the OIS resonant section 31 and the other end connected to the second stages 41X and 41Y. The OIS power transmission section 33 has an OIS motor contact section 33a, a stage fixing section 33c, and a connecting section 33b. The OIS motor contact section 33a is formed, for example, in a substantially L-shape in cross-section and contacts the free end of the arm section 31b of the OIS resonant section 31. The stage fixing section 33c is located at the end of the OIS power transmission section 33 and is fixed to the engaging pieces 41e and 41f (see Figure 4, etc.) of the second stages 41X and 41Y. The connecting section 33b is the part that connects the OIS motor contact section 33a and the stage fixing section 33c, and is formed by branching into two parallel to each other from the stage fixing section 33c.

[0038] The width between the OIS motor contact portions 33a is set to be wider than the width between the free ends of the arm portions 31b of the OIS resonant portion 31. As a result, when the OIS power transmission portion 33 is attached to the OIS resonant portion 31, the OIS power transmission portion 33 functions as a leaf spring, and a biasing force acts in the direction that pushes the arm portions 31b of the OIS resonant portion 31 outwards. This biasing force holds the OIS power transmission portion 33 between the free ends of the arm portions 31b of the OIS resonant portion 31, and the driving force from the OIS resonant portion 31 is efficiently transmitted to the OIS power transmission portion 33.

[0039] Since the OIS resonant section 31 and the OIS power transmission section 33 are only in contact while biased, the travel distance (stroke) of the OIS movable section 10 can be increased simply by enlarging the contact area in the X or Y direction, without increasing the external dimensions of the lens drive device 1.

[0040] The first OIS drive unit 30X is fixed to connect the base 21 and the second stage 41X, and the second OIS drive unit 30X is fixed to connect the base 21 and the second stage 41Y. When the first OIS drive unit 30X corrects the runout in the X direction, the second stage 41X and the first stage 12 move, while the second stage 41Y does not move. On the other hand, when the second OIS drive unit 30Y corrects the runout in the Y direction, the second stage 41Y and the first stage 12 move, while the second stage 41X does not move. In other words, the movement of the OIS movable part 10 by one OIS drive unit 30 is not hindered by the structure of the other OIS drive unit 30. Since rotation of the OIS movable part 10 around the Z axis can be prevented, the OIS movable part 10 can be precisely oscillated in the XY plane.

[0041] Figures 7 and 8 are exploded perspective views of the OIS movable part 10. Figure 8 shows Figure 7 rotated 90° around the Z-axis and viewed from below. Note that Figure 8 shows the AF drive unit 13 attached to the rotating spacer 15. As shown in Figures 7 and 8, in this embodiment, the OIS movable part 10 includes the AF movable part 11, the first stage 12, the AF drive part 13, the AF support part 14, and the rotating spacer 15, etc.

[0042] The AF movable part 11 is the part that moves in the optical axis direction when focusing. The AF movable part 11 is positioned radially apart from the first stage 12 (first fixed part) and is connected to the first stage 12 via the AF support part 14.

[0043] The AF movable part 11 is composed of a lens holder that holds the lens part 2 (see Figure 2) (hereinafter referred to as "lens holder 11"). The lens holder 11 is formed of, for example, polyarylate (PAR), a PAR alloy which is a mixture of multiple resin materials including PAR, or a liquid crystal polymer. The lens holder 11 has a cylindrical lens housing part 11a. The lens part 2 (see Figure 2) is fixed to the lens housing part 11a, for example, by adhesive.

[0044] The lens holder 11 has a sliding portion 11b projecting radially outward from the upper outer edge of the lens housing portion 11a. The lower surface 11c of the sliding portion 11b is formed to be inclined in the direction of the optical axis, and in conjunction with the rotation of the rotating spacer 15, the sliding portion 11b rises toward the image-forming side in the optical axis direction, causing the lens holder 11 to move in the direction of the optical axis.

[0045] The first stage 12 is the part that supports the lens holder 11 via the AF support section 14. Below the first stage 12, the second stages 41X and 41Y are positioned via a ball 43. During image stabilization, the first stage 12 moves in the X and Y directions in conjunction with the movement of the second stages 41X and 41Y.

[0046] The first stage 12 is a substantially rectangular cylindrical member, formed, for example, from a liquid crystal polymer. The first stage 12 has a substantially circular opening 12a in the portion corresponding to the lens holder 11. In the first stage 12, the portions corresponding to the second stages 41X and 41Y are formed to be thinner than the other portions by the thickness of the second stages 41X and 41Y.

[0047] The first stage 12 has a ball housing portion 12b on its lower surface for accommodating a ball 42 interposed between it and the base 21. The ball housing portion 12b is formed as a circular recess at a position opposite to the ball housing portion 21e of the base 21 in the Z direction. The first stage 12 also has ball housing portions 12m and 12n on its lower surface for accommodating a ball 43 interposed between it and the second stages 41X and 41Y. The ball housing portions 12m and 12n are formed as oval recesses extending in the Y and X directions, respectively, at positions opposite to the ball housing portions 41c and 41d of the second stages 41X and 41Y in the Z direction. The sides of the ball housing portions 12m and 12n are tapered so that the groove width narrows towards the bottom surface. The first stage 12 has upper spring fixing parts 12c at the four corners of its upper surface for fixing the AF support part 14. The upper spring fixing parts 12c are formed to protrude from the main surface 12j toward the light-receiving side in the optical axis direction.

[0048] The first stage 12 has a spacer placement section 12d and a motor fixing section 12f at the periphery of the aperture 12a. The spacer placement section 12d is formed recessed toward the optical axis imaging side compared to the main surface 12j and has a ball housing section 12e for housing the ball 17. The step difference between the spacer placement section 12d and the main surface 12j restricts the rotation of the rotating spacer 15. The AF drive unit 13 is fixed to the motor fixing section 12f.

[0049] In this embodiment, three spacer arrangement sections 12d are provided at equal intervals along the circumferential direction. This stabilizes the posture of the rotating spacer 15, allowing for precise control of the rotational movement. Note that two or more spacer arrangement sections 12d may be provided.

[0050] Although not shown in the diagram, wiring is arranged in the first stage 12, for example, by insert molding. The wiring is exposed from the first stage 12 as appropriate, and this portion is electrically connected to the AF drive unit 13 and the OIS biasing member 44. Power is supplied to the AF drive unit 13 via the OIS biasing member 44 and the wiring of the first stage 12.

[0051] Furthermore, on one side of the first stage 12 along the X direction and one side along the Y direction, engagement grooves 12g and 12h are provided at positions corresponding to the engagement pieces 41e and 41f of the second stages 41X and 41Y. When the lens drive device 1 is assembled, the engagement pieces 41e and 41f of the second stages 41X and 41Y engage with the engagement grooves 12g and 12h of the first stage 12. As a result, the OIS movable part 10 (first stage 12) moves in the X direction or the Y direction in conjunction with the movement of the second stages 41X and 41Y.

[0052] The AF support section 14 supports the lens holder 11 so that it can move in the optical axis direction relative to the first stage 12. In this embodiment, the AF support section 14 is composed of an upper spring that elastically supports the lens holder 11 on the light-receiving side (upper side) in the optical axis direction relative to the first stage 12 (hereinafter referred to as "upper spring 14"). The upper spring 14 is a leaf spring made of a metal material such as beryllium copper, nickel copper, or stainless steel.

[0053] The upper spring 14 has a lens holder fixing portion 14a, a stage fixing portion 14b, and an arm portion 14c. The lens holder fixing portion 14a has a shape corresponding to the upper surface of the lens housing portion 11a of the lens holder 11. The stage fixing portion 14b is provided at a position corresponding to the upper spring fixing portion 12c of the first stage 12. The arm portion 14c extends from the lens holder fixing portion 14a and connects the lens holder fixing portion 14a and the stage fixing portion 14b.

[0054] The upper spring 14 is positioned and fixed to the lens holder 11 by, for example, a positioning piece 14d provided on the lens holder fixing part 14a engaging with a positioning hole 11d provided on the slide part 11b of the lens holder 11. The upper spring 14 is also fixed to the first stage 12 by, for example, the stage fixing part 14b being bonded to the upper spring fixing part 12c of the first stage 12. When the lens holder 11 moves in the optical axis direction, the lens holder fixing part 14a is displaced together with the lens holder 11, and the arm part 14c is elastically deformed.

[0055] The rotating spacer 15 is a rotating body that rotates around the optical axis in response to the linear motion of the AF drive unit 13. The rotating spacer 15 has an annular shape and is positioned along the outer circumferential surface of the lens holder 11. The rotating spacer 15 also has a motor connection portion 15d to which the AF drive unit 13 is connected.

[0056] The rotating spacer 15 has an annular portion 15a and a stage fixing portion 15b. The stage fixing portion 15b is provided at a position corresponding to the spacer placement portion 12d of the first stage 12, and is formed to protrude, for example, from the annular portion 15a toward the imaging side in the optical axis direction. The upper surface 15c of the stage fixing portion 15b is formed to be inclined in the direction of the optical axis direction, and the sliding portion 11b of the lens holder 11 is placed on it (hereinafter referred to as the "holder guide portion 15c").

[0057] The holder guide portion 15c of the rotating spacer 15 and the sliding portion 11b of the lens holder 11 constitute an end face cam 18 (see Figure 10A, etc.) in which the sliding portion 11b slides along the holder guide portion 15c as the rotating spacer 15 rotates. The end face cam 18 is a mechanical element that converts rotational motion into linear motion in the direction of the optical axis.

[0058] In this embodiment, three end face cams 18 are provided at equal intervals along the circumferential direction. As a result, the rotational motion of the rotating spacer 15 is converted into linear motion by the end face cams 18 and transmitted evenly to the lens holder 11, so that the movement of the lens holder 11 can be controlled with high precision. Note that two or more end face cams 18 may be provided at equal intervals along the circumferential direction.

[0059] In this embodiment, a ball 16 is positioned between the holder guide portion 15c and the slide portion 11b, and the two are indirectly in contact, allowing the rotating spacer 15 and the lens holder 11 to slide smoothly. Alternatively, the ball 16 may be omitted between the rotating spacer 15 and the lens holder 11, allowing them to slide in direct contact. Furthermore, a ball 17 is positioned between the rotating spacer 15 and the first stage 12, allowing the rotating spacer 15 to rotate smoothly on the first stage 12.

[0060] The AF drive unit 13 is an actuator that moves the lens holder 11 in the Z direction. The AF drive unit 13, like the OIS drive unit 30, is composed of an ultrasonic motor. The AF drive unit 13 is fixed to the motor fixing part 12f of the first stage 12 so as to be along the circumferential surface of the rotating spacer 15.

[0061] The configuration of the AF drive unit 13 is shown in Figure 9. As shown in Figure 9, the AF drive unit 13 includes an AF resonant unit 131, an AF piezoelectric element 132, an AF electrode (not shown), and an AF power transmission unit 133. The AF resonant unit 131, the AF piezoelectric element 132, and the AF electrode (not shown) constitute an ultrasonic motor, and the driving force of the ultrasonic motor is transmitted to the rotating spacer 15 via the AF power transmission unit 133.

[0062] The AF piezoelectric element 132 is, for example, a plate-shaped element made of a ceramic material, and generates vibrations when a high-frequency voltage is applied. The AF electrode (not shown) sandwiches the AF resonant section 131 and the AF piezoelectric element 132, and applies a voltage to the AF piezoelectric element 132. The AF electrode is electrically connected, for example, to the wiring (not shown) of the first stage 12.

[0063] The AF resonant section 131 is made of a conductive material and resonates with the vibration of the AF piezoelectric element 132, converting the vibrational motion into linear motion. In this embodiment, the AF resonant section 131 has a substantially rectangular body portion 131a sandwiched between the AF piezoelectric element 132, two arm portions 131b extending from the upper and lower parts of the body portion 131a, a protruding portion 131c protruding from the central part of the body portion 131a, and a current-carrying portion 131d extending from the central part of the body portion 131a on the opposite side from the protruding portion 131c and electrically connected to the power supply path (wiring of the first stage 12). The two arm portions 131b have a symmetrical shape, and their respective free ends abut against the AF power transmission section 133, resonating with the vibration of the AF piezoelectric element 132 and deforming symmetrically.

[0064] An AF piezoelectric element 132 is attached to the body portion 131a of the AF resonant portion 131 from the thickness direction and sandwiched by AF electrodes (not shown), thereby electrically connecting them to each other. For example, when the energized portion 131d and AF electrodes of the AF resonant portion 131 are connected to the wiring (not shown) of the first stage 12, a voltage is applied to the AF piezoelectric element 132, causing vibration to occur.

[0065] The AF resonant section 131, like the OIS resonant section 31, has at least two resonant frequencies and deforms in a different manner for each resonant frequency. In other words, the overall shape of the AF resonant section 131 is set so that it deforms in a different manner for two resonant frequencies. These different behaviors are the behavior of the AF power transmission section 133 advancing along the circumferential direction and the behavior of it retracting.

[0066] The AF power transmission section 133 is a chucking guide extending circumferentially, with one end connected to the AF resonant section 131 and the other end connected to the rotating spacer 15. The AF power transmission section 133 has an AF motor contact section 133a, a spacer fixing section 133c, and a connecting section 133b. The AF motor contact section 133a is formed, for example, in a flat plate shape and contacts the free end of the arm section 131b of the AF resonant section 131. The spacer fixing section 133c is located at the end of the AF power transmission section 133 and is fixed to the motor connection section 15d of the rotating spacer 15. The connecting section 133b is the part that connects the AF motor contact section 133a and the spacer fixing section 133c, and is formed by branching into two from the spacer fixing section 133c, running parallel to each other and curved along the housing direction.

[0067] The AF power transmission unit 133 moves in response to the linear motion of the AF resonant unit 131. However, since one end of the AF power transmission unit 133 is connected to and constrained by the rotating spacer 15, the arm portion 131b of the AF resonant unit 131 and the AF motor contact portion 133a of the AF power transmission unit 133 slide against each other, causing the AF power transmission unit 133 to rotate. In other words, the AF drive unit 13, including the AF power transmission unit 133, can be said to convert vibrational motion into rotational motion.

[0068] The width between the AF motor contact portions 133a is set to be wider than the width between the free ends of the arm portions 131b of the AF resonant portion 131. As a result, when the AF power transmission portion 133 is attached to the AF resonant portion 131, the AF power transmission portion 133 functions as a leaf spring, and a biasing force acts in the direction that pushes the arm portions 131b of the AF resonant portion 131 outwards. This biasing force holds the AF power transmission portion 133 between the free ends of the arm portions 131b of the AF resonant portion 131, and the driving force from the AF resonant portion 131 is efficiently transmitted to the AF power transmission portion 133.

[0069] Since the AF resonance section 131 and the AF power transmission section 133 are only in contact while biased, the amount of rotation of the rotation spacer 15, that is, the travel distance of the lens holder 11 (stroke in the optical axis direction), can be increased simply by enlarging the contact area along the circumferential direction, without increasing the external dimensions of the lens drive device 1.

[0070] In the lens drive device 1, when a voltage is applied to the AF drive unit 13, the AF piezoelectric element 132 vibrates, and the AF resonant unit 131 deforms in a manner corresponding to the frequency. The driving force of the AF drive unit 13 causes the rotation spacer 15 to rotate, and the lens holder 11 moves in the optical axis direction, thereby performing focusing.

[0071] Specific examples of the behavior of the lens holder 11 in conjunction with the rotation of the rotating spacer 15 are shown in Figures 10A and 10B. Figure 10A shows the initial state in which the AF drive unit 13 is not driven, and Figure 10B shows the state in which the AF drive unit 13 is driven. As shown in Figures 10A and 10B, when the AF drive unit 13 is driven and the AF power transmission unit 133 is pulled towards the AF resonance unit 131, the rotating spacer 15 connected to the AF power transmission unit 133 rotates. Consequently, the end face cam 18 operates, causing the sliding portion 11b of the lens holder 11 to rise along the holder guide portion 15c of the rotating spacer 15, and the lens holder 11 moves toward the light-receiving side in the optical axis direction.

[0072] In the lens drive device 1, when a voltage is applied to the OIS drive unit 30, the OIS piezoelectric element 32 vibrates, and the OIS resonant unit 31 deforms in a manner corresponding to the frequency. The driving force of the OIS drive unit 30 causes the OIS power transmission unit 33 to slide in the X or Y direction. Consequently, the OIS movable unit 10 moves in the X or Y direction, and vibration correction is performed.

[0073] Specifically, when the first OIS drive unit 30X is driven and the OIS power transmission unit 33 moves in the X direction, power is transmitted from the base 21 on which the first OIS drive unit 30X is located to the second stage 41X. The ball 42 (located in the ball housing 21d) held between the second stage 41X and the base 21 is positioned to roll in the X direction, so the second stage 41X moves in the X direction relative to the base 21. The ball 43 (located in the ball housing 41c) held between the first stage 12 and the second stage 41X cannot roll in the X direction, so the position of the first stage 12 in the X direction relative to the second stage 41X is maintained, and the first stage 12 moves in the X direction in conjunction with the second stage 41X. At this time, the ball 43 (located in the ball housing 41d) held between the second stage 41Y and the first stage 12 is arranged to be rotatable in the X direction, so the first stage 12 slides smoothly on the second stage 41Y. In addition, the movement of the second stage 41Y in the X direction relative to the base 21 is restricted by the ball 42 (located in the ball housing 21e) held between the second stage 41Y and the base 21. Therefore, the second stage 41Y does not displace relative to the base 21, and only the second stage 41X and the first stage 12 move in the X direction.

[0074] Similarly, when the second OIS drive unit 30Y is driven and the OIS power transmission unit 33 moves in the Y direction, power is transmitted from the base 21 on which the second OIS drive unit 30Y is located to the second stage 41Y. The ball 42 (the ball 42 located in the ball housing 21e) held between the second stage 41Y and the base 21 is positioned to roll in the Y direction, so the second stage 41Y moves in the Y direction relative to the base 21. The ball 43 (the ball 43 located in the ball housing 41d) held between the first stage 12 and the second stage 41Y cannot roll in the Y direction, so the position of the first stage 12 in the Y direction relative to the second stage 41Y is maintained, and the first stage 12 moves in the Y direction in conjunction with the second stage 41Y. At this time, the ball 43 (located in the ball housing 41c) held between the second stage 41X and the first stage 12 is arranged to be rotatable in the Y direction, so the first stage 12 slides smoothly on the second stage 41X. In addition, the movement of the second stage 41X in the Y direction relative to the base 21 is restricted by the ball 42 (located in the ball housing 21d) held between the second stage 41X and the base 21. Therefore, the second stage 41X does not displace relative to the base 21, and only the second stage 41Y and the first stage 12 move in the Y direction.

[0075] Thus, the second stages 41X and 41Y do not interfere with each other and can move independently. In other words, the first OIS drive unit 30X connected to the second stage 41X is not subjected to a force in the Y direction due to the movement of the second stage 41Y, and the second OIS drive unit 30Y connected to the second stage 41Y is not subjected to a force in the X direction due to the movement of the second stage 41X. Therefore, runout correction in the XY plane can be performed with high accuracy.

[0076] In this way, the OIS movable part 10 oscillates in the XY plane, and shake correction is performed. Specifically, the voltage supplied to the OIS drive unit 30 is controlled based on a detection signal indicating angular shake from the shake detection unit (e.g., a gyro sensor, not shown) so that the angular shake of the camera module A is canceled out. At this time, the translational movement of the OIS movable part 10 can be accurately controlled by feeding back the detection results of the XY position detection unit, which is composed of magnets 52X, 52Y and Hall elements 51X, 51Y.

[0077] As described above, the lens drive device 1 according to this embodiment includes a first stage 12 (first fixed part), a lens holder 11 (first movable part) that holds the lens part 2 and is positioned apart from the first stage 12, an AF support part 14 (first support part) that supports the lens holder 11 relative to the first stage 12, and an AF drive unit 13 (Z-direction drive unit) which is composed of an ultrasonic motor that converts vibrational motion into linear motion and moves the lens holder 11 in the optical axis direction (Z direction) relative to the first stage 12. The lens drive device 1 also includes a rotating spacer 15 (rotating body) that rotates around the optical axis in response to the linear motion of the AF drive unit 13, and an end face cam 18 (mechanical element) that converts the rotational motion of the rotating spacer 15 into linear motion in the optical axis direction, and the lens holder 11 moves in the optical axis direction as the rotating spacer 15 rotates.

[0078] According to the lens drive unit 1, since the AF drive unit 13 is composed of an ultrasonic motor, the influence of external magnetism can be reduced, and miniaturization and a low profile can be achieved. Therefore, even if the camera module A having the lens drive unit 1 is placed in close proximity, as in a smartphone M, there is no magnetic influence, making it extremely suitable for dual cameras.

[0079] Although the present invention has been specifically described above based on embodiments, the present invention is not limited to the above embodiments and can be modified without departing from its spirit.

[0080] For example, in the embodiment, a smartphone M, which is a mobile terminal with a camera, was described as an example of a camera-mounted device equipped with a camera module A. However, the present invention can be applied to a camera-mounted device having a camera module and an image processing unit that processes image information obtained by the camera module. Camera-mounted devices include information equipment and transportation equipment. Information equipment includes, for example, mobile phones with cameras, notebook computers, tablet terminals, portable game consoles, webcams, and in-vehicle devices with cameras (e.g., rearview monitors, drive recorders). Transportation equipment includes, for example, automobiles.

[0081] Figures 11A and 11B show a vehicle V as a camera-mounted device equipped with an in-vehicle camera module VC (Vehicle Camera). Figure 11A is a front view of vehicle V, and Figure 11B is a rear perspective view of vehicle V. Vehicle V is equipped with the camera module A described in the embodiment as the in-vehicle camera module VC. As shown in Figures 11A and 11B, the in-vehicle camera module VC can be mounted, for example, on the windshield facing forward, or on the rear gate facing backward. This in-vehicle camera module VC is used for purposes such as a backup monitor, a drive recorder, collision avoidance control, and autonomous driving control.

[0082] Furthermore, in this embodiment, an end face cam 18 is used, which is composed of the sliding portion 11b of the lens holder 11 and the holder guide portion 15c of the rotating spacer 15. However, other cam structures or the like may be applied to the mechanical element interposed between the lens holder 11 and the rotating spacer 15.

[0083] Furthermore, in this embodiment, the AF drive unit 13 rotates the rotation spacer 15, and the end face cam 18 converts the rotational motion into linear motion to move the lens holder 11 in the optical axis direction. However, the lens holder 11 may be rotated while moving in the optical axis direction, that is, the lens holder 11 may function as a rotating body and be made to perform helical motion. In this case, a mechanical element is provided between the lens holder 11 and the first stage 12.

[0084] Furthermore, the present invention can be applied not only to autofocus but also to zoom and other cases where the first movable part (lens holder 11) is moved in the optical axis direction.

[0085] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the claims rather than by the foregoing description, and all modifications within the meaning and scope equivalent to the claims are intended to be included. [Explanation of symbols]

[0086] 1. Lens drive device 10 OIS moving part (second moving part) 11 AF movable part, lens holder (first movable part) 11b Slide section 12. Stage 1 (First Fixed Section) 13 AF drive unit (Z direction drive unit) 14 AF support section, upper spring (first support section) 15 Rotation Spacer 15c Holder guide section 16, 17 Ball 18 End face cam (machine element) 20 OIS fixing part (second fixing part) 30. OIS drive unit (XY direction drive unit) 40 OIS support part (second support part)

Claims

1. A fixing portion having a shape surrounding a circular opening and an outer periphery on which wiring is arranged, wherein a recess opening upward and concave downward is provided in an arc shape along the circumferential direction on the outer periphery, A ring-shaped rotating body disposed on the outer circumference of the fixed part, having an annular portion extending along the circumferential direction and a protruding portion that protrudes downward from the annular portion at a position corresponding to the recess, A sliding support portion that supports the sliding of the rotating body relative to the fixed portion at the position where the recess and the protrusion are provided, A drive unit comprising a fixed portion fixed to the fixed part and a movable portion fixed to the rotating body, wherein the fixed portion receives power via the wiring and the movable portion transmits driving force to the rotating body, causing the rotating body to rotate along the circumferential direction, A rotary drive device having the following features.

2. The sliding support portion is a ball interposed between the fixed portion and the rotating body. The recess and the protrusion are provided at multiple different positions in the circumferential direction. The balls, which are arranged at the multiple positions that are different in the circumferential direction, support the rotating body that rotates along the circumferential direction at the multiple positions. The rotary drive device according to claim 1.

3. Each of the plurality of balls supports the corresponding projection in the corresponding recess, The rotary drive device according to claim 2.

4. The plurality of positions are spaced equally apart in the circumferential direction. The rotary drive device according to claim 2.

5. The rotary drive device according to claim 1, wherein the fixed portion includes an ultrasonic motor comprising a piezoelectric element that generates vibration and a resonant portion that resonates with the vibration and generates linear motion, and the movable portion has a power transmission portion that is connected at both ends to the resonant portion and the rotating body and moves in the circumferential direction in response to the linear motion.

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