Lens driving device, camera module and camera mounting device

Abstract

The invention provides a lens driving device, a camera module and a camera mounting device which can reduce the influence of external magnetism and realize miniaturization and low height. The lens driving device (1) comprises a first fixing part (12); a first movable part (11); a first support part (14); and a Z-direction drive unit (13) that is configured from an ultrasonic motor that converts vibration motion into rotational motion, and that moves the first movable unit in the optical axis direction (Z-direction) with respect to the first fixed unit. The lens driving device further comprises a rotating body (15) which rotates with the optical axis as the center under the action of the rotating motion of the Z-direction driving part; and a mechanical element that converts rotational motion of the rotating body into linear motion in the optical axis direction, and that moves the first movable part in the optical axis direction by being rotated by the rotating body.

Description

Technical Field

[0001] The invention relates to a lens driving device, a camera module and a camera mounting device. Background Art

[0002] Generally, a small camera module is mounted in a portable terminal such as a smartphone. Such a camera module has a lens driving device having an autofocus function (hereinafter referred to as "AF function") for automatically focusing when photographing a subject, and a shake correction function (hereinafter referred to as "OIS function") for optically correcting shake (vibration) generated during shooting to reduce image blur (for example, Patent Document 1).

[0003] The lens driving device having the AF function and the OIS function includes an autofocus driving unit (hereinafter referred to as the "AF driving unit") for moving the lens unit along the optical axis direction, and a shake correction driving unit (hereinafter referred to as the "OIS driving unit") for swinging the lens unit in a plane perpendicular to the optical axis direction. In Patent Document 1, a voice coil motor (VCM) is applied to the AF driving unit and the OIS driving unit.

[0004] In recent years, camera modules having multiple (typically two) lens drive devices (so-called dual-lens cameras) have been put into practical use. Dual-lens cameras can simultaneously capture two images with different focal distances, or can simultaneously capture a still image and a moving image, and have various possibilities depending on the scenario in which they are used.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2013-210550

[0008] Patent Document 2: International Publication No. 2015 / 123787 Summary of the invention

[0009] Problem that the invention aims to solve

[0010] However, as disclosed in Patent Document 1, a lens driving device using a VCM is affected by external magnetism, so high-precision operation may be impaired. In particular, in a dual-lens camera in which lens driving devices are arranged side by side, there is a high possibility of magnetic interference between the lens driving devices.

[0011] On the other hand, a lens driving device using ultrasonic motors in the AF driving unit and the OIS driving unit is disclosed in Patent Document 2. Since the lens driving device disclosed in Patent Document 2 has no magnet, it can reduce the influence of external magnetism, but the structure is relatively complex and it is difficult to achieve miniaturization and low height.

[0012] An object of the present invention is to provide a lens driving device, a camera module, and a camera mounting device that can reduce the influence of external magnetism and achieve miniaturization and low height.

[0013] Solutions to the problem

[0014] The lens driving device of the present invention comprises:

[0015] a first fixing portion;

[0016] A first movable part, comprising a lens holder for holding a lens part, and arranged to be spaced apart from the first fixed part;

[0017] a first supporting portion, supporting the first movable portion on the first fixed portion; and

[0018] The Z-direction driving part is composed of an ultrasonic motor that converts vibration motion into linear motion, and is used to move the first movable part relative to the first fixed part in the optical axis direction. The lens driving device has:

[0019] a rotating body that rotates around the optical axis under the action of the linear motion of the Z-direction driving unit; and

[0020] a mechanical element, which converts the rotational motion of the rotating body into a linear motion along the optical axis,

[0021] The first movable portion moves in the optical axis direction due to the rotation of the rotating body.

[0022] The camera module of the present invention comprises:

[0023] The lens driving device mentioned above;

[0024] a lens portion mounted on the first movable portion; and

[0025] The imaging unit captures an image of the object formed by the lens unit.

[0026] The camera-mounted device of the present invention is an information device or a transportation device, which comprises:

[0027] The camera module mentioned above; and

[0028] The image processing unit processes the image information obtained by the camera module.

[0029] Effects of the Invention

[0030] According to the present invention, it is possible to provide a lens driving device, a camera module, and a camera mounting device that can reduce the influence of external magnetism and achieve miniaturization and low height. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1A , Figure 1B This is a diagram showing a smartphone equipped with a camera module according to an embodiment of the present invention.

[0032] Figure 2 This is a stereoscopic view of the camera module.

[0033] Figure 3A , Figure 3B This is a perspective view of the appearance of the lens driving device.

[0034] Figure 4 It is an exploded perspective view of the lens driving device.

[0035] Figure 5 It is an exploded perspective view of the lens driving device.

[0036] Fig. 6A , Figure 6B is a perspective view of a first OIS driving unit.

[0037] Figure 7 This is an exploded perspective view of the OIS movable part.

[0038] Figure 8 This is an exploded perspective view of the OIS movable part.

[0039] Fig. 9 It is a perspective view of the AF drive unit.

[0040] Fig. 10A , Fig. 10B It is a diagram showing the movement of the lens holder accompanying the rotation of the rotating washer.

[0041] Fig.11A , Fig. 11B FIG. 1 is a diagram showing a car as a camera mounting device on which a vehicle-mounted camera module is mounted. DETAILED DESCRIPTION

[0042] Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

[0043] Figure 1A , Figure 1B The diagram shows a smartphone M (an example of a camera-mounted device) equipped with a camera module A according to an embodiment of the present invention. Figure 1A is the main view of smartphone M, Figure 1B is a rear view of the smartphone M.

[0044] The smartphone M has a dual-lens 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.

[0045] The camera module A has an AF function and an OIS function, and can automatically focus on the subject when photographing, and can optically correct the shake (vibration) generated during photography to capture an unblurred image.

[0046] Figure 2 This is a perspective view of the appearance of camera module A. Figure 3A , Figure 3B It is a perspective view of the appearance of the lens driving device 1 . Figure 3B Show that Figure 3A The state after rotating 180° around the Z axis. Figure 2 , Figure 3A and Figure 3B As shown, in this embodiment, the description is made using an orthogonal coordinate system (X, Y, Z). In the following drawings, the same orthogonal coordinate system (X, Y, Z) is also used.

[0047] For example, the camera module A is mounted in such a manner that the X direction becomes the up-down direction (or the left-right direction), the Y direction becomes the left-right direction (or the up-down direction), and the Z direction becomes the front-back direction when the smartphone M actually takes a picture. That is, the Z direction is the optical axis direction, the upper side (+Z side) in the figure is the light receiving side (subject side) in the optical axis direction, and the lower side (-Z side) is the imaging side in the optical axis direction. In addition, the X direction and the Y direction are "optical axis orthogonal directions" orthogonal to the Z axis, and the XY plane is an "optical axis orthogonal plane" orthogonal to the optical axis.

[0048] like Figure 2 As shown in the figures, the camera module A comprises: a lens driving device 1 for realizing AF function and OIS function, a lens unit 2 in which the lens is housed in a cylindrical lens barrel, a camera unit (not shown) for photographing an image of a subject formed by the lens unit 2, and a cover 3 for covering the whole.

[0049] The cover 3 is a covered quadrangular cylinder that is rectangular in shape when viewed from above in the direction of the optical axis. In the present embodiment, the cover 3 is square in shape when viewed from above. The cover 3 has a substantially circular opening 3a on the upper surface. The lens portion 2 faces outward from the opening 3a and is configured to protrude toward a position closer to the light receiving side than the opening surface of the cover 3 as it moves in the direction of the optical axis. The cover 3 is fixed to the OIS fixing portion 20 (see FIG. 2 ) of the lens driving device 1 by, for example, bonding. Figure 4 ).

[0050] The imaging unit (not shown in the figure) is arranged on the imaging side of the optical axis direction of the lens driving device 1. The imaging unit (not shown in the figure) has, for example, an image sensor substrate and an imaging element mounted on the image sensor substrate. The imaging element is composed of, for example, a CCD (charge-coupled device) type image sensor, a CMOS (complementary metal oxide semiconductor) type image sensor, etc. The imaging element captures the image of the subject formed by the lens unit 2. The lens driving device 1 is mounted on the image sensor substrate (not shown in the figure) and is mechanically and electrically connected thereto. The control unit that performs drive control of the lens driving device 1 can be provided on the image sensor substrate or on a camera-mounted device (in this embodiment, a smartphone M) that mounts the camera module A.

[0051] Figure 4 , Figure 5 It is an exploded perspective view of the lens driving device 1 . Figure 5 Show that Figure 4 Rotated 90° around the Z axis and viewed from below.

[0052] like Figure 4 , Figure 5 As shown, in this embodiment, the lens driving device 1 includes: an OIS movable part 10 (second movable part), an OIS fixed part 20 (second fixed part), an OIS driving part 30 (XY direction driving part) and an OIS supporting part 40 (second supporting part).

[0053] The OIS movable part 10 is a part that swings in a plane orthogonal to the optical axis during shake correction. The OIS movable part 10 includes an AF unit, which has an AF movable part 11 (first movable part), a first stage 12 (first fixed part), an AF driving part 13 (Z-direction driving part), an AF supporting part 14 (first supporting part), and a rotating spacer 15 (see Figure 7 wait).

[0054] The OIS fixing part 20 is a part connected to the OIS movable part 10 via the OIS supporting part 40. The OIS fixing part 20 includes a base 21.

[0055] The OIS support part 40 supports the OIS movable part 10 on the OIS fixed part 20 while the OIS movable part 10 is spaced apart from the OIS fixed part 20 in the optical axis direction. The OIS support part 40 includes second stages 41X and 41Y, balls 42 and 43, and an OIS urging member 44.

[0056] The OIS movable part 10 is arranged to be 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. In addition, the OIS movable part 10 and the OIS fixed part 20 are urged toward each other by OIS urging members 44 provided at four locations on the outer peripheral surface of the OIS movable part 10.

[0057] In this embodiment, the OIS movable part 10 can be swung accurately in the XY plane by limiting the rotatable directions of the balls 42 and 43 (11 in total) constituting the OIS support part 40. The number of balls 42 and 43 constituting the OIS support part 40 can be changed as appropriate.

[0058] The base 21 is a component that is rectangular in plan view and has a circular opening 21a in the center and is formed by the following molding material, for example, polyarylate (PAR), PAR alloy (PAR Alloy, for example, PAR / PC) formed by a mixture of multiple resin materials including PAR, or liquid crystal polymer (LCP: Liquid Crystal Polymer).

[0059] The chassis 21 has OIS motor fixing parts 21b at two corners where the OIS driver 30 is arranged. The OIS motor fixing parts 21b are formed to protrude from the main surface of the chassis 21 toward the light receiving side in the optical axis direction and have a shape capable of holding the OIS driver 30.

[0060] Although not shown in the figure, terminal metal parts and wiring are arranged on the base 21 by, for example, insert molding. In addition, a sensor substrate on which the Hall elements 51X and 51Y are mounted is arranged on the base 21.

[0061] The wiring includes the AF drive unit 13 (refer to Figure 7 The wiring is exposed from the peripheral edge of the base 21, for example, and is electrically connected to the wiring formed on the sensor substrate and the OIS urging member 44.

[0062] In addition, the base 21 has ball receiving parts 21c, 21d, and 21e for receiving the ball 42. The ball receiving part 21c is formed as a circular depression, and receives the ball 42 between the base 21 and the first platform 12. The ball receiving part 21d is formed as a rectangular depression extending in the X direction, and receives the ball 42 between the base 21 and the second platform 41X. The ball receiving part 21e is formed as a rectangular depression extending in the Y direction, and receives the ball 42 between the base 21 and the second platform 41Y. The side surfaces of the ball receiving parts 21d and 21e are formed in a tapered shape, for example, in such a manner that the groove width becomes narrower toward the bottom surface side.

[0063] The sensor substrate (not shown) has wiring (not shown) including power supply lines and signal lines for the Hall elements 51X and 51Y. The Hall elements 51X and 51Y are electrically connected to the wiring (not shown) of the base 21 through the wiring (not shown) formed on the sensor substrate. In the second stage 41X and 41Y, magnets 52X and 52Y are arranged at positions opposite to the Hall elements 51X and 51Y. The position of the OIS movable part 10 in the X and Y directions is detected by the XY position detection unit composed of the Hall elements 51X and 51Y and the magnets 52X and 52Y.

[0064] The second stage 41X, 41Y is formed of, for example, a liquid crystal polymer and is L-shaped as a whole. The inner circumferential surface of the second stage 41X, 41Y is formed in an arc shape along the outer shape of the lens holder 11. The second stage 41X, 41Y is arranged along the X direction and the Y direction, respectively. In addition, the second stage 41X, 41Y is spaced apart at a predetermined interval at a portion where they are close to each other, so that the second stage 41X, 41Y can move independently of each other.

[0065] The outer side surfaces of the second stage portions 41X and 41Y are formed to be recessed inward, and when the lens driving device 1 is assembled, the OIS driving parts 30X and 30Y are located on the outer side surfaces of the second stage portions 41X and 41Y. In the present embodiment, the second stage portions 41X and 41Y are formed to be L-shaped as a whole, and the second stage portions 41X and 41Y are arranged below the thin-walled portion of the first stage portion 12, thereby achieving a low height of the OIS movable part 10.

[0066] The second stage 41X, 41Y is provided with engaging pieces 41e, 41f protruding toward the light receiving side in the optical axis direction at the periphery. One end of the OIS power transmission part 33 is fixed to the engaging pieces 41e, 41f. In addition, the engaging pieces 41e, 41f are movably engaged with the engaging grooves 12g, 12h provided on the first stage 12. Specifically, the engaging piece 41e is engaged with the engaging groove 12g to the extent that at least when the first stage 12 moves in the Y direction, the surfaces opposite to each other in the Y direction do not abut against each other; the engaging piece 41f is engaged with the engaging groove 12h to the extent that at least when the first stage 12 moves in the X direction, the surfaces opposite to each other in the X direction do not abut against each other. In other words, even if the first stage 12 moves in the Y direction, the second stage 41X will not be displaced; even if the first stage 12 moves in the X direction, the second stage 41Y will not be displaced.

[0067] Each of the second stage parts 41X and 41Y has three ball receiving parts 41a and 41b for receiving the ball 42 on the lower surface (the surface on the imaging side in the optical axis direction). The ball receiving parts 41a and 41b are opposite to the ball receiving parts 21d and 21e of the base 21. The ball receiving part 41a is formed as an oblong depression extending in the X direction, and the ball receiving part 41b is formed as an oblong depression extending in the Y direction. In addition, the side surfaces of the ball receiving parts 41a and 41b are formed in a tapered shape in such a way that the groove width becomes narrower toward the bottom surface side.

[0068] In addition, each of the second stage parts 41X and 41Y has two ball receiving parts 41c and 41d on the upper surface (the surface on the light receiving side in the optical axis direction) for receiving the ball 43. The ball receiving part 41c is formed as an oblong depression extending in the Y direction, and the ball receiving part 41d is formed as an oblong depression extending in the X direction. The side surfaces of the ball receiving parts 41c and 41d are formed in a tapered shape so that the groove width becomes narrower toward the bottom surface side.

[0069] The ball 42 is held by the ball receiving parts 21c to 21e of the base 21, the ball receiving part 12b of the first platform 12, and the ball receiving parts 41a and 41b of the second platforms 41X and 41Y. The ball 42 makes multi-point contact between the ball receiving parts 21d and 21e of the base 21 and the ball receiving parts 41a and 41b of the second platforms 41X and 41Y. Therefore, the ball 42 stably rotates in the X direction or the Y direction.

[0070] In addition, the ball 43 is held in multi-point contact by the ball receiving portions 41c and 41d of the second stage portions 41X and 41Y and the lower surface of the first stage portion 12. Therefore, the ball 43 stably rotates in the X direction or the Y direction.

[0071] The OIS force-applying member 44 is, for example, composed of a helical tension spring, and connects the OIS movable part 10 and the OIS fixed part 20. In the present embodiment, one end of the OIS force-applying 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 force-applying member 44 is subjected to a tensile load when the OIS movable part 10 and the OIS fixed part 20 are connected, so that the OIS movable part 10 and the OIS fixed part 20 are close to each other. That is, the OIS movable part 10 is maintained to be swingable in the XY plane in a state where it is forced by the OIS force-applying member 44 along the optical axis direction (in a state where it is pressed against the base 21). Thus, the OIS movable part 10 can be maintained in a stable state without vibration.

[0072] In addition, in the present embodiment, the OIS urging member 44 functions as a power supply line to the AF drive unit 13 .

[0073] The OIS driving unit 30 is an actuator that moves the OIS movable unit 10 in the X direction and the Y direction. Specifically, the OIS driving unit 30 includes a first OIS driving unit 30X (first XY direction driving unit) that moves the OIS movable unit 10 in the X direction, and a second OIS driving unit 30Y (second XY direction driving unit) that moves the OIS movable unit 10 in the Y direction.

[0074] The first OIS driving unit 30X is fixed to the OIS motor fixing unit 21b of the base 21 so as to extend in the X direction. The second OIS driving unit 30Y is fixed to the OIS motor fixing unit 21b of the base 21 so as to extend in the Y direction. That is, the first OIS driving unit 30X and the second OIS driving unit 30Y are arranged along sides orthogonal to each other.

[0075] The structure of the OIS driving unit 30 is as follows Fig. 6A , Figure 6B shown. Fig. 6A 2 shows the state in which the components of the OIS driving unit 30 are assembled. Figure 6B 2 shows a state where the components of the OIS driving unit 30 are disassembled. Fig. 6A , Figure 6B The second OIS driving unit 30Y is shown, but the main structure of the first OIS driving unit 30X is the same as that of the second OIS driving unit 30Y, so Fig. 6A , Figure 6B It is considered to be a diagram showing the OIS driving unit 30.

[0076] like Fig. 6A , Figure 6B As shown, the OIS driving unit 30 includes an OIS resonance unit 31, an OIS piezoelectric element 32, an OIS electrode (not shown), and an OIS power transmission unit 33. The OIS resonance 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 stage units 41X and 41Y through the OIS power transmission unit 33.

[0077] The OIS piezoelectric element 32 is a plate-shaped element formed of, for example, a ceramic material, and vibrates when a high-frequency voltage is applied.

[0078] The OIS electrode (not shown) sandwiches the OIS resonance portion 31 and the OIS piezoelectric element 32, and applies a voltage to the OIS piezoelectric element 32. The OIS electrode is electrically connected to a wiring (not shown) of the chassis 21, for example.

[0079] The OIS resonance part 31 is formed of a conductive material, resonates with the vibration of the OIS piezoelectric element 32, and converts the vibration motion into a linear motion. In the present embodiment, the OIS resonance part 31 has: a substantially rectangular body 31a sandwiched by the OIS piezoelectric element 32, two arms 31b extending from the upper and lower parts of the body 31a, a protrusion 31c protruding from the central part of the body 31a, and a power-carrying part 31d extending from the central part of the body 31a to the side opposite to the protrusion 31c. The power-carrying part 31d is electrically connected to the wiring of the base 21, for example. The two arms 31b have a symmetrical shape, and their free ends abut against the OIS power transmission part 33, and resonate with the vibration of the OIS piezoelectric element 32 and deform symmetrically.

[0080] The OIS piezoelectric element 32 is attached to the body 31a of the OIS resonance part 31 in the thickness direction and is sandwiched by the OIS electrode (not shown), so that they are electrically connected to each other. For example, one side of the power supply path is connected to the OIS electrode, and the other side is connected to the power supply part 31d of the OIS resonance part 31, thereby applying a voltage to the OIS piezoelectric element 32 to generate vibration.

[0081] The OIS resonance part 31 has at least two resonance frequencies, and deforms in different motions with respect to each resonance frequency. In other words, the overall shape of the OIS resonance part 31 is set in such a way that it deforms in different motions with respect to the two resonance frequencies. The different motions refer to the motion of moving the OIS power transmission part 33 forward in the X direction or the Y direction, and the motion of moving backward in the X direction or the Y direction.

[0082] The OIS power transmission part 33 is a clamping guide extending in one direction, one end of which is connected to the OIS resonance part 31, and the other end is connected to the second platform 41X, 41Y. The OIS power transmission part 33 has an OIS motor abutment part 33a, a platform fixing part 33c, and a connecting part 33b. The OIS motor abutment part 33a is formed, for example, so that its cross-section is roughly L-shaped, and abuts against the free end of the arm part 31b of the OIS resonance part 31. The platform fixing part 33c is arranged at the end of the OIS power transmission part 33 and is fixed to the locking pieces 41e, 41f of the second platform 41X, 41Y (see Figure 4 The connecting portion 33b is a portion connecting the OIS motor contact portion 33a and the table fixing portion 33c, and is formed as two portions branched from the table fixing portion 33c and parallel to each other.

[0083] The width between the OIS motor abutment portions 33a is set to be wider than the width between the free ends of the arm portions 31b of the OIS resonance portion 31. Thus, when the OIS power transmission portion 33 is mounted on the OIS resonance portion 31, the OIS power transmission portion 33 functions as a leaf spring, and a pushing force acts in a direction to expand the arm portions 31b of the OIS resonance portion 31. By this pushing force, the OIS power transmission portion 33 is held between the free ends of the arm portions 31b of the OIS resonance portion 31, so that the driving force from the OIS resonance portion 31 is efficiently transmitted to the OIS power transmission portion 33.

[0084] The OIS resonance part 31 and the OIS power transmission part 33 only contact each other under the applied force. Therefore, if the contact part is enlarged in the X direction or the Y direction, the moving distance (stroke) of the OIS movable part 10 can be increased without increasing the outer shape of the lens driving device 1 .

[0085] The first OIS driving unit 30X is fixed so as to connect the base 21 and the second stage 41X, and the second OIS driving unit 30X is fixed so as to connect the base 21 and the second stage 41Y.

[0086] When the first OIS driving unit 30X performs the shake correction in the X direction, the second stage 41X and the first stage 12 move, but the second stage 41Y does not move. On the other hand, when the second OIS driving unit 30Y performs the shake correction in the Y direction, the second stage 41Y and the first stage 12 move, but the second stage 41X does not move. That is, the movement of the OIS movable unit 10 performed by the OIS driving unit 30 on one side is not hindered by the structure of the OIS driving unit 30 on the other side. Since the rotation of the OIS movable unit 10 around the Z axis can be prevented, the OIS movable unit 10 can be swung in the XY plane with good accuracy.

[0087] Figure 7 , Figure 8 It is an exploded perspective view of the OIS movable part 10 . Figure 8 Show Figure 7 The figure is rotated 90° around the Z axis and viewed from below. Figure 8 2 shows a state where the AF driving unit 13 is mounted on the rotating spacer 15 .

[0088] like Figure 7 , Figure 8 As shown, in this embodiment, the OIS movable section 10 includes an AF movable section 11, a first stage section 12, an AF driving section 13, an AF supporting section 14, a rotating spacer 15, and the like.

[0089] The AF movable section 11 is a portion that moves in the optical axis direction during focusing, and is disposed radially apart from the first stage section 12 (first fixed section), and is connected to the first stage section 12 via the AF support section 14 .

[0090] The AF movable section 11 is formed by holding the lens section 2 (see Figure 2 ) is formed of a lens holder (hereinafter referred to as "lens holder 11"). The lens holder 11 is formed of, for example, polyarylate (PAR), PAR alloy formed by mixing various resin materials including PAR, liquid crystal polymer, etc. The lens holder 11 has a cylindrical lens receiving portion 11a. The lens portion 2 (see Figure 2 ) is fixed to the lens housing portion 11a by, for example, bonding.

[0091] The lens holder 11 has a sliding portion 11b protruding radially outward at the upper outer peripheral edge of the lens receiving portion 11a. The lower surface 11c of the sliding portion 11b is formed to be inclined in the optical axis direction, and the sliding portion 11b is linked with the rotation of the rotating gasket 15 to gradually rise toward the imaging side in the optical axis direction, so that the lens holder 11 moves along the optical axis direction.

[0092] The first stage 12 is a portion that supports the lens holder 11 via the AF support portion 14. The second stages 41X and 41Y are disposed below the first stage 12 via the ball 43. The first stage 12 moves in the X and Y directions in conjunction with the movement of the second stages 41X and 41Y during shake correction.

[0093] The first stage 12 is a substantially rectangular cylindrical member, and is formed of, for example, a liquid crystal polymer. The first stage 12 has a substantially circular opening 12a at a portion corresponding to the lens holder 11. In the first stage 12, a portion corresponding to the second stage 41X, 41Y is formed so that the wall thickness is smaller than the other portion by the thickness of the second stage 41X, 41Y.

[0094] The first platform 12 has a ball receiving portion 12b on the lower surface for receiving a ball 42, and the ball 42 is interposed between the first platform 12 and the base 21. The ball receiving portion 12b is formed as a circular depression at a position opposite to the ball receiving portion 21c of the base 21 in the Z direction. In addition, the first platform 12 has ball receiving portions 12m and 12n on the lower surface for receiving a ball 43, and the ball 43 is interposed between the first platform 12 and the second platforms 41X and 41Y. The ball receiving portion 12m is formed as an oblong depression extending in the Y direction at a position opposite to the ball receiving portion 41c of the second platform 41X in the Z direction, and the ball receiving portion 12n is formed as an oblong depression extending in the X direction at a position opposite to the ball receiving portion 41d of the second platform 41Y in the Z direction. The side surfaces of the ball receiving portions 12m and 12n are formed in a tapered shape in such a way that the groove width narrows toward the bottom surface side.

[0095] The first stage 12 has upper spring fixing portions 12c at three of the four corners of the upper surface to fix the AF support portion 14. The upper spring fixing portions 12c are formed to protrude further toward the light receiving side in the optical axis direction than the main surface 12j.

[0096] The first stage 12 has a gasket arrangement portion 12d and a motor fixing portion 12f at the peripheral portion of the opening 12a. The gasket arrangement portion 12d is formed to be recessed toward the imaging side in the optical axis direction relative to the main surface 12j, and has a ball receiving portion 12e for receiving the ball 17. The rotation of the rotating gasket 15 is restricted by the height difference between the gasket arrangement portion 12d and the main surface 12j. The AF drive unit 13 is fixed to the motor fixing portion 12f.

[0097] In this embodiment, three shim arrangement portions 12d are arranged at equal intervals along the circumferential direction. As a result, the posture of the rotating shim 15 is stabilized, so the rotational motion can be controlled with good accuracy. In addition, two or more shim arrangement portions 12d may be provided.

[0098] Although not shown in the figure, wiring is arranged on the first stage 12 by insert molding, for example. The wiring is appropriately exposed from the first stage 12, and this part is electrically connected to the AF driving unit 13 and the OIS urging member 44. The AF driving unit 13 is powered by the wiring of the OIS urging member 44 and the first stage 12.

[0099] In addition, engagement grooves 12g and 12h are provided on the side surface along one side of the X direction and the side surface along one side of the Y direction of the first stage 12, at positions corresponding to the engagement pieces 41e and 41f of the second stage 41X and 41Y. When the lens driving device 1 is assembled, the engagement pieces 41e and 41f of the second stage 41X and 41Y engage with the engagement grooves 12g and 12h of the first stage 12. Thus, 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 stage 41X and 41Y.

[0100] The AF support portion 14 supports the lens holder 11 on the first stage 12 so that the lens holder 11 can move along the optical axis direction. In the present embodiment, the AF support portion 14 is composed of an upper spring (hereinafter referred to as "upper spring 14"), which elastically supports the lens holder 11 on the light receiving side (upper side) in the optical axis direction on the first stage 12. The upper spring 14 is a leaf spring made of a metal material such as beryllium copper, nickel copper, stainless steel, etc.

[0101] The upper spring 14 includes 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 receiving 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 to connect the lens holder fixing portion 14a to the stage fixing portion 14b.

[0102] For example, the upper spring 14 is positioned and fixed relative to the lens holder 11 by engaging the positioning piece 14d provided on the lens holder fixing portion 14a with the positioning hole 11d provided on the sliding portion 11b of the lens holder 11. In addition, for example, the upper spring 14 is fixed relative to the first stage 12 by bonding the stage fixing portion 14b to the upper spring fixing portion 12c of the first stage 12. When the lens holder 11 moves along the optical axis direction, the lens holder fixing portion 14a is displaced together with the lens holder 11, and the arm portion 14c is elastically deformed.

[0103] The rotary washer 15 is a rotating body that rotates around the optical axis by the linear motion of the AF drive unit 13. The rotary washer 15 has an annular shape and is arranged along the outer peripheral surface of the lens holder 11. The rotary washer 15 has a motor connection portion 15d to which the AF drive unit 13 is connected.

[0104] The rotating washer 15 includes an annular portion 15a and a stage fixing portion 15b. The stage fixing portion 15b is provided at a position corresponding to the washer arrangement portion 12d of the first stage 12, and is formed, for example, to protrude from the annular portion 15a toward the imaging side in the optical axis direction. An upper surface 15c of the stage fixing portion 15b is formed to be inclined in the optical axis direction, and a sliding portion 11b (hereinafter referred to as a "holder guide portion 15c") of the lens holder 11 is placed thereon.

[0105] The holder guide portion 15c of the rotating washer 15 and the sliding portion 11b of the lens holder 11 constitute an end face cam 18 (see Fig. 10A In the end face cam 18, the sliding portion 11b slides along the holder guide portion 15c as the rotating washer 15 rotates. The end face cam 18 is a mechanical element that converts a rotational motion into a linear motion in the optical axis direction.

[0106] In this embodiment, three end face cams 18 are arranged at equal intervals along the circumferential direction. Thus, the rotational motion of the rotating gasket 15 is converted into linear motion by the end face cams 18 and evenly transmitted to the lens holder 11, so that the movement of the lens holder 11 can be controlled with good accuracy. In addition, two or more end face cams 18 may be arranged at equal intervals along the circumferential direction.

[0107] In this embodiment, the ball 16 is arranged between the holder guide portion 15c and the sliding portion 11b, and the holder guide portion 15c and the sliding portion 11b are indirectly in contact with each other, so that the rotating gasket 15 and the lens holder 11 slide smoothly. In addition, the ball 16 may not be arranged between the rotating gasket 15 and the lens holder 11, and the rotating gasket 15 and the lens holder 11 may be directly in contact with each other and slide.

[0108] In addition, a ball 17 is disposed between the rotating washer 15 and the first stage 12 , so that the rotating washer 15 can smoothly rotate on the first stage 12 .

[0109] The AF drive unit 13 is an actuator that moves the lens holder 11 in the Z direction. The AF drive unit 13 is formed of an ultrasonic motor similar to the OIS drive unit 30. The AF drive unit 13 is fixed to the motor fixing portion 12f of the first stage 12 along the circumference of the rotating spacer 15.

[0110] The structure of the AF driving unit 13 is as follows: Fig. 9 shown.

[0111] like Fig. 9 As shown, the AF driving unit 13 includes an AF resonance unit 131, an AF piezoelectric element 132, an AF electrode (not shown), and an AF power transmission unit 133. The AF resonance 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 pad 15 through the AF power transmission unit 133.

[0112] The AF piezoelectric element 132 is a plate-shaped element formed of, for example, a ceramic material, and generates vibrations when a high-frequency voltage is applied.

[0113] The AF electrode (not shown) sandwiches the AF resonance unit 131 and the AF piezoelectric element 132, and applies a voltage to the AF piezoelectric element 132. The AF electrode is electrically connected to a wiring (not shown) of the first stage unit 12, for example.

[0114] The AF resonance part 131 is formed of a conductive material, resonates with the vibration of the AF piezoelectric element 132, and converts the vibration motion into a linear motion. In this embodiment, the AF resonance part 131 has a substantially rectangular body 131a sandwiched by the AF piezoelectric element 132, two arms 131b extending from the upper and lower parts of the body 131a, a protrusion 131c protruding from the center of the body 131a, and a power supply part 131d extending from the center of the body 131a to the side opposite to the protrusion 131c and electrically connected to the power supply path (wiring of the first stage 12). The two arms 131b have a symmetrical shape, and the free ends of each of them abut against the AF power transmission part 133, and resonate with the vibration of the AF piezoelectric element 132 and deform symmetrically.

[0115] The AF piezoelectric element 132 is attached to the body portion 131a of the AF resonance portion 131 in the thickness direction and is sandwiched by the AF electrode (not shown) so that they are electrically connected to each other. For example, the current-carrying portion 131d of the AF resonance portion 131 and the AF electrode are connected to the wiring (not shown) of the first stage portion 12, thereby applying a voltage to the AF piezoelectric element 132 to generate vibration.

[0116] The AF resonance part 131 has at least two resonance frequencies, similarly to the OIS resonance part 31, and deforms in different motions with respect to the respective resonance frequencies. In other words, the overall shape of the AF resonance part 131 is set so as to deform in different motions with respect to the two resonance frequencies. The different motions refer to the motion of moving the AF power transmission part 133 forward in the circumferential direction and the motion of moving backward in the circumferential direction.

[0117] The AF power transmission part 133 is a clamping guide extending in the circumferential direction, one end of which is connected to the AF resonance part 131, and the other end of which is connected to the rotating gasket 15. The AF power transmission part 133 has: an AF motor abutment part 133a, a gasket fixing part 133c, and a connecting part 133b. The AF motor abutment part 133a is formed in a flat plate shape, for example, and abuts against the free end of the arm part 131b of the AF resonance part 131. The gasket fixing part 133c is arranged at the end of the AF power transmission part 133 and is fixed to the motor connecting part 15d of the rotating gasket 15. The connecting part 133b is a part that connects the AF motor abutment part 133a and the gasket fixing part 133c, and is formed as two parts that branch from the gasket fixing part 133c, are parallel to each other and are bent in the circumferential direction.

[0118] The AF power transmission part 133 moves due to the linear motion of the AF resonance part 131, but one end of the AF power transmission part 133 is connected to the rotating gasket 15 and is restricted, so the arm part 131b of the AF resonance part 131 slides with the AF motor abutment part 133a of the AF power transmission part 133, so that the AF power transmission part 133 rotates. That is, the AF driving part 13, including the AF power transmission part 133, can be said to convert the vibration motion into the rotation motion.

[0119] The width between the AF motor abutment portions 133a is set to be wider than the width between the free ends of the arm portions 131b of the AF resonance portion 131. Thus, when the AF power transmission portion 133 is mounted on the AF resonance portion 131, the AF power transmission portion 133 functions as a leaf spring, and a pressing force acts in a direction to expand the arm portions 131b of the AF resonance portion 131. By this pressing force, the AF power transmission portion 133 is held between the free ends of the arm portions 131b of the AF resonance portion 131, so that the driving force from the AF resonance portion 131 is efficiently transmitted to the AF power transmission portion 133.

[0120] The AF resonance part 131 and the AF power transmission part 133 only abut against each other when force is applied. Therefore, as long as the abutting part is enlarged along the circumferential direction, the rotation amount of the rotating gasket 15, that is, the moving distance (stroke in the optical axis direction) of the lens holder 11 can be lengthened without increasing the shape of the lens driving device 1.

[0121] In the lens driving device 1, when a voltage is applied to the AF driving unit 13, the AF piezoelectric element 132 vibrates and the AF resonance unit 131 deforms in accordance with the frequency. The driving force of the AF driving unit 13 rotates the rotary washer 15 and the lens holder 11 moves in the optical axis direction, thereby focusing.

[0122] The specific example of the movement of the lens holder 11 accompanying the rotation of the rotary washer 15 is Fig. 10A , Fig. 10B shown. Fig. 10A shows an initial state where the AF driving section 13 is not driven. Fig. 10B The AF driving section 13 is shown in a driven state.

[0123] like Fig. 10A , Fig. 10B As shown in the figure, when the AF driving section 13 is driven and the AF power transmission section 133 is pulled toward the AF resonance section 131, the rotating washer 15 connected to the AF power transmission section 133 rotates. In response, the end face cam 18 operates, and the sliding section 11b of the lens holder 11 gradually rises along the holder guide section 15c of the rotating washer 15, and the lens holder 11 moves toward the light receiving side in the optical axis direction.

[0124] In the lens driving device 1, when a voltage is applied to the OIS driving unit 30, the OIS piezoelectric element 32 vibrates, and the OIS resonance unit 31 deforms in accordance with the frequency. The OIS power transmission unit 33 slides in the X direction or the Y direction by the driving force of the OIS driving unit 30. Accordingly, the OIS movable unit 10 moves in the X direction or the Y direction, thereby performing shake correction.

[0125] Specifically, when the first OIS driving unit 30X is driven and the OIS power transmission unit 33 moves in the X direction, the power is transmitted from the base 21 on which the first OIS driving unit 30X is configured to the second stage 41X. The ball 42 (the ball 42 configured in the ball receiving portion 21d) clamped by the second stage 41X and the base 21 is configured to be rotatable in the X direction, so the second stage 41X moves in the X direction relative to the base 21. The ball 43 (the ball 43 configured in the ball receiving portion 41c) clamped by the first stage 12 and the second stage 41X cannot rotate in the X direction, so the position of the first stage 12 in the X direction relative to the second stage 41X remains unchanged, and the first stage 12 and the second stage 41X move in the X direction in conjunction.

[0126] At this time, the ball 43 (the ball 43 disposed in the ball receiving portion 41d) held by the second stage 41Y and the first stage 12 is configured to be rotatable in the X direction, so that the first stage 12 slides smoothly on the second stage 41Y. In addition, the movement of the second stage 41Y relative to the base 21 in the X direction is restricted by the ball 42 (the ball 42 disposed in the ball receiving portion 21e) held by the second stage 41Y and the base 21.

[0127] 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.

[0128] Similarly, when the second OIS driving unit 30Y is driven and the OIS power transmission unit 33 moves in the Y direction, the power is transmitted from the base 21 on which the second OIS driving unit 30Y is configured to the second stage 41Y. The ball 42 (the ball 42 configured in the ball receiving portion 21e) clamped by the second stage 41Y and the base 21 is configured to be rotatable 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 configured in the ball receiving portion 41d) clamped by the first stage 12 and the second stage 41Y cannot rotate in the Y direction, so the position of the first stage 12 in the Y direction relative to the second stage 41Y remains unchanged, and the first stage 12 moves in the Y direction in conjunction with the second stage 41Y.

[0129] At this time, the ball 43 (the ball 43 disposed in the ball receiving portion 41c) held by the second stage 41X and the first stage 12 is configured to be rotatable in the Y direction, so the first stage 12 slides smoothly on the second stage 41X. In addition, the second stage 41X is restricted from moving relative to the base 21 in the Y direction by the ball 42 (the ball 42 disposed in the ball receiving portion 21d) held by the second stage 41X and the base 21.

[0130] 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.

[0131] In this way, the second stages 41X and 41Y do not interfere with each other and can move independently. That is, the first OIS driving unit 30X connected to the second stage 41X will not be subjected to a force in the Y direction due to the movement of the second stage 41Y, and the second OIS driving unit 30Y connected to the second stage 41Y will not be subjected to a force in the X direction due to the movement of the second stage 41X. Therefore, the shake correction in the XY plane can be performed with good accuracy.

[0132] In this way, the OIS movable part 10 swings in the XY plane, thereby performing shake correction. Specifically, the energization voltage to the OIS driving part 30 is controlled based on the detection signal indicating the angular shake from the shake detection part (for example, a gyro sensor, not shown) so that the angular shake of the camera module A is offset. At this time, by feeding back the detection result of the XY position detection part composed of the magnets 52X, 52Y and the Hall elements 51X, 51Y, the translation movement of the OIS movable part 10 can be accurately controlled.

[0133] Thus, the lens driving device 1 of the embodiment comprises: a first stage 12 (first fixed part); a lens holder 11 (first movable part) which holds the lens unit 2 and is arranged to be spaced apart from the first stage 12; an AF support part 14 (first support part) which supports the lens holder 11 on the first stage 12; and an AF driving part 13 (Z direction driving part) which is composed of an ultrasonic motor which converts vibration 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 driving device 1 comprises: a rotating washer 15 (rotating body) which is rotated around the optical axis by the linear motion of the AF driving part 13; and an end face cam 18 (mechanical element) which converts the rotational motion of the rotating washer 15 into linear motion in the optical axis direction, and the lens holder 11 is moved in the optical axis direction by the rotation of the rotating washer 15.

[0134] According to the lens driving device 1, since the AF driving unit 13 is composed of an ultrasonic motor, the influence of external magnetism can be reduced, and miniaturization and low height can be achieved. Therefore, even if the camera modules A having the lens driving device 1 are arranged close to each other like a smartphone M, there will be no magnetic influence, so it is very suitable for use in a dual-lens camera.

[0135] As mentioned above, the invention completed by the present inventors has been specifically described based on the embodiments, but the present invention is not limited to the above-mentioned embodiments and can be modified within the scope not departing from the gist thereof.

[0136] For example, in the embodiment, as an example of a camera-mounted device having a camera module A, a smartphone M as a portable terminal with a camera is cited for description, but 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. The camera-mounted device includes information equipment and transportation equipment. Information equipment includes, for example, a portable phone with a camera, a laptop computer, a tablet terminal, a portable game console, a web camera, and a vehicle-mounted device with a camera (for example, a rear monitoring device, a driving recorder device). In addition, transportation equipment includes, for example, a car.

[0137] Fig.11A , Fig. 11B 1 is a diagram showing a car V as a camera mounting device on which a vehicle-mounted camera module VC (Vehicle Camera) is mounted. Fig.11A This is the front view of the car V. Fig. 11B FIG. 2 is a rear perspective view of a car V. The car V is equipped with the camera module A described in the embodiment as a vehicle-mounted camera module VC. Fig.11A , Fig. 11B As shown, the vehicle-mounted camera module VC is mounted on a windshield facing forward, or mounted on a tailgate facing backward. The vehicle-mounted camera module VC is used for rear monitoring, driving recorder, collision avoidance control, automatic driving control, and the like.

[0138] In the embodiment, the end face cam 18 composed of the sliding portion 11 b of the lens holder 11 and the holder guide portion 15 c of the rotating washer 15 is used, but other cam structures may be applied as a mechanical element between the lens holder 11 and the rotating washer 15 .

[0139] In the embodiment, the rotating washer 15 is rotated by the AF driving unit 13, 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 moved in the optical axis direction while rotating, that is, the lens holder 11 is made to function as a rotating body and perform a spiral motion. In this case, a mechanical element is provided between the lens holder 11 and the first stage 12.

[0140] The present invention can be applied not only to the case of performing autofocus but also to the case of moving the first movable portion (lens holder 11) in the optical axis direction, such as zooming.

[0141] The embodiments disclosed this time should be considered as illustrative in all aspects and not restrictive. The scope of the present invention is indicated by the claims rather than the above description, and includes the meaning equivalent to the claims and all modifications within the scope of the claims.

[0142] The disclosure of Japanese Patent Application No. 2019-107368 filed on June 7, 2019, including the specification, drawings, and abstract, is incorporated herein by reference in its entirety.

[0143] Description of Reference Numerals

[0144] 1 Lens driving device 10 OIS movable part (second movable part)

[0145] 11AF movable part, lens holder (first movable part) 11b sliding part 12 first stage part (first fixed part)

[0146] 13AF drive unit (Z direction drive unit)

[0147] 14AF support part, upper spring (first support part) 15 Rotating washer

[0148] 15c Bracket guide

[0149] 16, 17 ball 18 end face cam (mechanical element)

[0150] 20OIS fixing part (second fixing part)

[0151] 30OIS drive unit (XY direction drive unit)

[0152] 40OIS support part (second support part)

Claims

1. A lens driving device, comprising: a first fixing portion; A first movable part, comprising a lens holder for holding a lens part, and arranged to be spaced apart from the first fixed part; a first supporting portion, supporting the first movable portion on the first fixed portion; and A Z-direction driving part, which is composed of an ultrasonic motor that converts vibration motion into linear motion, is used to move the first movable part relative to the first fixed part in the optical axis direction. The lens driving device also comprises: a rotating body that rotates around the optical axis under the action of the linear motion of the Z-direction driving unit; and a mechanical element, which converts the rotational motion of the rotating body into a linear motion along the optical axis, The first movable portion moves in the optical axis direction due to the rotation of the rotating body.

2. The lens driving device according to claim 1, wherein: A ring-shaped rotating gasket is provided, the rotating gasket is arranged along the outer peripheral surface of the lens holder, and is connected to the Z-direction driving unit to function as the rotating body. The lens bracket is connected to the rotating gasket through the mechanical element.

3. The lens driving device according to claim 2, wherein: The rotating gasket has a support guide portion inclined along the circumferential direction on the surface of the light receiving side in the optical axis direction. The lens holder has a sliding portion that abuts against the holder guide portion. The holder guide portion and the sliding portion slide along with the rotation of the rotary washer, and constitute an end face cam functioning as the mechanical element.

4. The lens driving device according to claim 3, wherein: A plurality of the end surface cams are arranged at equal intervals in the circumferential direction.

5. The lens driving device according to claim 3 or 4, wherein: A ball is arranged between the holder guide portion and the sliding portion.

6. The lens driving device according to claim 1, wherein: The lens holder is connected to the first fixing portion through the mechanical element and is connected to the Z-direction driving portion to function as the rotating body and to perform a spiral motion under the effect of the rotational motion.

7. The lens driving device according to claim 1, further comprising: A second movable part, comprising the first fixed part, the first movable part, the first supporting part and the Z-direction driving part; a second fixed portion, arranged to be spaced apart from the second movable portion; a second supporting portion, supporting the second movable portion on the second fixed portion; as well as The XY direction driving unit moves the second movable unit relative to the second fixed unit within an optical axis orthogonal plane that is orthogonal to the optical axis direction.

8. The lens driving device according to claim 7, wherein: The XY direction driving part is composed of an ultrasonic motor that converts vibration motion into linear motion.

9. A camera module comprising: The lens driving device according to any one of claims 1 to 8; a lens portion mounted on the first movable portion; and The imaging unit captures an image of the object formed by the lens unit.

10. A camera-mounted device, which is information equipment or transportation equipment, comprising: The camera module of claim 9; and The image processing unit processes the image information obtained by the camera module.

Images