Optical element driving device, camera module, and camera mounting device

Abstract

The invention provides an optical element driving device, a camera module, and a camera mounting device, which can realize stabilization of moving operation of a movable part and are high in reliability. The optical element driving device includes: a fixed portion; a movable part that includes an optical element and is movable with respect to the fixed part via a rolling body; an ultrasonic motor-type drive unit that is disposed on an active-side member comprising either the fixed unit or the movable unit, and that moves the movable unit with respect to the fixed unit; and a power transmission unit that connects the drive unit and a passive-side member configured from the other of the fixed unit and the movable unit, and transmits the power of the drive unit to the passive-side member. The drive section has a resonance section having a pair of vibrating arms, and the power transmission section has a guide section for guiding the rolling body, and is sandwiched by the pair of arms in a biased state.

Description

Technical Field

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

[0002] Generally, a small camera module is mounted on a portable terminal such as a smartphone. Such a camera module uses an optical element driving device, which has an auto focus function (hereinafter referred to as "AF function", AF: Auto Focus) for automatically focusing when photographing a subject and a shake correction function (hereinafter referred to as "OIS function", OIS: Optical Image Stabilization) for optically correcting shake (vibration) generated during shooting to reduce image blur (for example, Patent Document 1).

[0003] An optical element driving device having an AF function and an OIS function includes an autofocus driving unit (hereinafter referred to as an "AF driving unit") for moving a lens unit in an optical axis direction and a shake correction driving unit (hereinafter referred to as an "OIS driving unit") for moving a lens unit in a plane orthogonal to the optical axis direction. In Patent Document 1, an ultrasonic motor type driving unit is applied to the AF driving unit and the OIS driving unit.

[0004] The ultrasonic motor type drive unit includes a resonance part (resonator) as an active element. The ultrasonic motor type drive unit is provided with a resonance part in an active side component formed by either a movable part or a fixed part, and transmits power to a passive side component formed by either the movable part or the fixed part via a power transmission part as a passive element. The resonance part and the power transmission part are in contact with each other in a state of being applied force, and slide against each other during driving. The "active side component" is a component provided with the drive unit, and the "passive side component" is a component connected to the drive unit via the power transmission part.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: International Publication No. 2015 / 123787 Summary of the invention

[0008] Problems to be solved by the invention

[0009] Usually, in an ultrasonic motor type drive unit, the active element, passive element, movable part, and fixed part are designed so that the moving direction of the movable part and the direction of power transmission are consistent. However, due to installation tolerances, etc., sometimes there is a deviation between the installation angle of the passive element relative to the active element and the installation angle of the movable part relative to the fixed part. This deviation will also affect the contact state between the active element and the passive element, making the two components difficult to slide. Therefore, there is a concern that the power transmitted to the movable part will become unstable.

[0010] An object of the present invention is to provide a highly reliable optical element driving device, a camera module, and a camera mounting device that can stabilize the movement of a movable portion.

[0011] Means for solving problems

[0012] The optical element driving device of the present invention comprises:

[0013] Fixed part;

[0014] A movable part including an optical element and capable of moving relative to the fixed part via a rolling body;

[0015] an ultrasonic motor type driving section which is disposed on an active-side member formed by either the fixed section or the movable section and moves the movable section relative to the fixed section; and

[0016] a power transmission part that connects the passive side member formed by the other of the fixed part and the movable part and the driving part, and transmits the power of the driving part to the passive side member,

[0017] The driving unit has a resonance unit having a pair of vibrating arms.

[0018] The power transmission portion includes a guide portion for guiding the rolling element, and is sandwiched by the pair of arms in a biased state.

[0019] The camera module of the present invention comprises:

[0020] The above-mentioned optical element driving device;

[0021] an optical element mounted on the movable portion; and

[0022] The imaging unit captures the subject image formed by the optical element.

[0023] The camera-mounted device of the present invention is an information device or a transport device, which comprises:

[0024] The camera module mentioned above; and

[0025] The image processing unit processes the image information obtained by the camera module.

[0026] Effects of the Invention

[0027] According to the present invention, it is possible to provide a highly reliable optical element driving device, a camera module, and a camera mounting device capable of stabilizing power transmission from an active element to a passive element and improving driving performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] 1A and 1B are diagrams showing a smartphone equipped with a camera module according to an embodiment of the present invention.

[0029] FIG. 2 is a perspective view of the appearance of a camera module.

[0030] FIG. 3 is a perspective view of the appearance of the optical element driving device.

[0031] FIG. 4 is a perspective view of the appearance of the optical element driving device.

[0032] FIG. 5 is an exploded perspective view of the optical element driving device.

[0033] FIG. 6 is an exploded perspective view of the optical element driving device.

[0034] 7A and 7B are plan views of the second stage portion.

[0035] FIG8 is an exploded perspective view of the AF unit.

[0036] FIG. 9 is an exploded perspective view of the AF unit.

[0037] 10A and 10B are enlarged views of the OIS driving unit.

[0038] 11A and 11B are schematic diagrams of a power transmission mechanism in an OIS driving unit.

[0039] FIG12 is an enlarged view of the AF drive unit.

[0040] 13A and 13B are diagrams showing a car as a camera mounting device equipped with a vehicle-mounted camera module. DETAILED DESCRIPTION

[0041] Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

[0042] 1A and 1B are diagrams showing a smartphone M (an example of a camera-mounted device) equipped with a camera module A according to an embodiment of the present invention. FIG1A is a front view of the smartphone M, and FIG1B is a rear view of the smartphone M.

[0043] The smartphone M has a dual camera including two rear cameras OC1 and OC2. In the present embodiment, the camera module A is applied to the rear cameras OC1 and OC2.

[0044] The camera module A has an AF function and an OIS function, and can automatically focus when photographing a subject, and can optically correct shake (vibration) generated during photographing to photograph an image without image blur.

[0045] FIG. 2 is a perspective view of the appearance of a camera module A. FIG. 3 and FIG. 4 are perspective views of the appearance of an optical element driving device 1 according to an embodiment. FIG. 4 shows a state in which FIG. 3 is rotated 90° about the Z axis. As shown in FIG. 2 to FIG. 4, in the embodiment, an orthogonal coordinate system (X, Y, Z) is used for description. The following figures are also represented by a common orthogonal coordinate system (X, Y, Z).

[0046] The camera module A is mounted in a manner such that, for example, when the smartphone M is used for actual shooting, the X-axis direction is the up-down direction (or the left-right direction), the Y-axis direction is the left-right direction (or the up-down direction), and the Z-axis direction is the front-back direction. That is, the Z-axis direction is the optical axis direction, the upper side (+Z side) in the figure is the light receiving side in the optical axis direction, and the lower side (-Z side) is the imaging side in the optical axis direction. In addition, the X-axis direction and the Y-axis direction orthogonal to the Z-axis are referred to as "directions orthogonal to the optical axis", and the XY plane is referred to as "plane orthogonal to the optical axis".

[0047] As shown in Fig. 2 to Fig. 4, the camera module A includes an optical element driving device 1 for realizing the AF function and the OIS function, a lens unit 2 in which a lens is housed in a cylindrical lens barrel, and an imaging unit 3 for capturing an image of a subject formed by the lens unit 2. That is, the optical element driving device 1 is a lens driving device for driving the lens unit 2 as an optical element.

[0048] The imaging unit 3 is arranged on the imaging side of the optical axis direction of the optical element driving device 1. The imaging unit 3 has, for example, an image sensor substrate 301, an imaging element 302 mounted on the image sensor substrate 301, and a control unit 303. The imaging element 302 is composed of, for example, a CCD (charge-coupled device) type image sensor, a CMOS (complementary metal oxide semiconductor) type image sensor, etc., and captures the subject image formed by the lens unit 2. The control unit 303 is composed of, for example, a control IC, and performs driving control of the optical element driving device 1. The optical element driving device 1 is mounted on the image sensor substrate 301, and is mechanically and electrically connected to the image sensor substrate 301. In addition, the control unit 303 can also be set on the image sensor substrate 301, and can also be set on a camera-mounted device (a smart phone M in the embodiment) equipped with a camera module A.

[0049] The outer side of the optical element driving device 1 is covered by a cover 24. The cover 24 is a covered square cylinder that is rectangular in a planar perspective as viewed from the optical axis direction. In an embodiment, the cover 24 is square in a planar perspective. The cover 24 has a substantially circular opening 241 on the surface (upper surface) on the light-receiving side in the optical axis direction. The lens portion 2 faces the outside from the opening 241 of the cover 24. The lens portion 2 can also be configured to protrude more toward the light-receiving side than the opening surface of the cover 24. The cover 24 is fixed to the base 21 of the OIS fixing portion 20 of the optical element driving device 1 by, for example, bonding (refer to FIG. 5 ).

[0050] Fig. 5 and Fig. 6 are exploded perspective views of the optical element driving device 1 of the embodiment. Fig. 7A and Fig. 7B are plan views of the second stage 13. Fig. 8 and Fig. 9 are exploded perspective views of the AF unit 10A. Fig. 6 and Fig. 9 respectively show the state in which Fig. 5 and Fig. 8 are rotated 90° around the Z axis.

[0051] As shown in FIGS. 5 to 9 , the optical element driving device 1 of the present embodiment includes an OIS movable portion 10 , an OIS fixed portion 20 , an X-axis direction driving unit 50X, a Y-axis direction driving unit 50Y, and OIS supporting portions 41 and 42 .

[0052] The OIS movable part 10 is a part that moves in a plane orthogonal to the optical axis during shake correction. The OIS movable part 10 includes an AF unit 10A and a second stage 13. The OIS fixed part 20 is a part connected to the OIS movable part 10 via the OIS support part 41. The OIS fixed part 20 includes a base 21.

[0053] The OIS movable part 10 is arranged to be separated from the OIS fixed part 20 in the optical axis direction, and is connected to the OIS fixed part 20 via the OIS supporting parts 41 and 42. The OIS movable part 10 and the OIS fixed part 20 are urged in a direction toward each other by the OIS urging member 30. The OIS urging member 30 is arranged, for example, at the four corners of the optical element driving device 1 in a planar view.

[0054] The OIS urging member 30 is composed of, for example, a tension coil spring, and connects the OIS movable part 10 and the OIS fixed part 20. In the present embodiment, one end of the OIS urging member 30 is connected to a wiring (not shown) of the base 21, and the other end is connected to the terminal metal fitting 162 of the first stage 12. The OIS urging member 30 functions as a power supply line to the AF drive unit 70 and the Y-axis direction drive unit 50Y.

[0055] The OIS force applying member 30 bears the tensile load when the OIS movable part 10 and the OIS fixed part 20 are connected, so as to act in a manner that the OIS movable part 10 and the OIS fixed part 20 are close to each other. As a result, the OIS movable part 10 is kept in a state where a force is applied along the optical axis direction (a state where it is pressed against the base 21) and can move in the XY plane. Therefore, the OIS movable part 10 can be kept in a stable state without shaking. In addition, the OIS force applying member 30 can also be configured with a buffer material (not shown) that suppresses vibration.

[0056] The OIS support part 41 supports the second stage 13 functioning as the OIS movable part 10 on the base 21 functioning as the OIS fixed part 20 in a state separated in the optical axis direction. In the present embodiment, the OIS support part 41 is composed of four balls interposed between the base 21 and the second stage 13 in a rollable state. In addition, the number of balls constituting the OIS support part 41 can be appropriately changed.

[0057] The OIS support part 42 supports the first stage 12 functioning as the OIS movable part 10 on the second stage 13 functioning as the OIS fixed part 20 in a state separated in the optical axis direction. In the present embodiment, the OIS support part 42 is composed of four balls interposed between the second stage 13 and the first stage 12 in a rollable state. In addition, the number of balls constituting the OIS support part 42 can be appropriately changed.

[0058] In this embodiment, regarding the movement in the X-axis direction, the entire OIS movable section 10 including the AF unit 10A moves as a movable body. On the other hand, regarding the movement in the Y-axis direction, only the AF unit 10A moves as a movable body. That is, regarding the movement in the Y-axis direction, the second stage 13 and the base 21 together constitute the OIS fixed section 20.

[0059] The base 21 is formed of a molding material such as polyarylate (PAR), a PAR alloy containing a plurality of resin materials including PAR (eg, PAR / PC), or a liquid crystal polymer. The base 21 is a rectangular member in a planar view and has a circular opening 211 in the center.

[0060] The base 21 has an OIS motor fixing portion 212 on which the X-axis direction driving unit 50X is disposed. The OIS motor fixing portion 212 is formed, for example, protruding toward the light receiving side in the optical axis direction on one side along the X-axis of the outer periphery of the base 21, and has a shape capable of holding the X-axis direction driving unit 50X. With respect to the movement of the OIS movable portion 10 in the X-axis direction, the base 21 functions as an active side component.

[0061] The base 21 supports the second stage 13 of the OIS movable part 10 via the OIS support part 41 so as to be movable in the X-axis direction. The base 21 has an OIS ball retaining part 214 on which the OIS support part 41 is arranged on the surface of the light-receiving side in the optical axis direction. The OIS ball retaining part 214 is, for example, a groove having a rectangular shape extending in the X-axis direction in a planar view. The OIS ball retaining part 214 is formed into a substantially V-shaped (conical) cross-sectional shape in a manner such that the groove width becomes narrower toward the bottom surface side. In the present embodiment, the OIS ball retaining part 214 is disposed near the four corners of the base 21, and the OIS movable part 10 (second stage 13) is supported at four points by four OIS support parts 41 arranged on the OIS ball retaining part 214.

[0062] The base 21 is provided with a terminal metal member 22 and wiring (not shown) connected to the terminal metal member 22 by, for example, insert molding. The terminal metal member 22 is exposed from the base 21, and is, for example, electrically connected to the image sensor substrate 301. In addition, the wiring is electrically connected to the OIS force applying member 30. Power is supplied to the AF drive unit 70 and the Y-axis direction drive unit 50Y via the OIS force applying member 30. In addition, a sensor substrate may be provided on the base 21, and the wiring of the sensor substrate may be electrically connected to the terminal metal member 22.

[0063] A position detection sensor for detecting the position of the OIS movable part 10 in the X-axis direction and the Y-axis direction and the position of the AF movable part 11 in the Z-axis direction may be arranged on the base 21. For example, the position detection sensor may be a magnetic sensor such as a Hall element or a TMR (Tunnel Magneto Resistance) sensor. In this case, a magnet is arranged on the OIS movable part 10 (for example, the first stage 12) and the AF movable part 11 in a manner opposite to the magnetic sensor. In addition, the position of the OIS movable part 10 in the X-axis direction and the Y-axis direction and the position of the AF movable part 11 in the Z-axis direction may be detected by an optical sensor such as a photo reflector.

[0064] The second stage portion 13 is a member having a substantially rectangular shape in a planar view as viewed from the optical axis direction, and is formed of, for example, a liquid crystal polymer. The second stage portion 13 has an opening 131 at a portion corresponding to the AF movable portion 11 .

[0065] The portion 132 of the second stage 13 corresponding to the X-axis direction drive unit 50X is formed to be recessed radially inward so that the X-axis direction drive unit 50X can be arranged without protruding radially outward. In addition, the portion 133 of the second stage 13 corresponding to the Y-axis direction drive unit 50Y is also formed to be recessed radially inward (hereinafter referred to as "OIS motor fixing portions 132, 133").

[0066] The X-axis direction power transmission unit 60X is fixed to the OIS motor fixing unit 132. The Y-axis direction power transmission unit 60Y is fixed to the OIS motor fixing unit 133. The second stage unit 13 functions as a passive side member for movement of the OIS movable unit 10 in the X-axis direction and the Y-axis direction.

[0067] The second stage 13 supports the first stage 12 of the AF unit 10A via the OIS support portion 42 so as to be movable in the Y-axis direction. The second stage 13 has an OIS ball holding portion 134 on which the OIS support portion 42 is arranged on the surface (upper surface) on the light receiving side in the optical axis direction. The OIS ball holding portion 134 is, for example, a rectangular groove extending in the Y-axis direction in a planar view. The OIS ball holding portion 134 is formed into a substantially V-shaped (tapered) cross-sectional shape, for example, so that the groove width becomes narrower toward the bottom surface side.

[0068] In the present embodiment, the OIS ball holder 134 is provided near the four corners of the second stage 13, and the AF unit 10A (first stage 12) is supported at four points by the four OIS support portions 42 disposed on the OIS ball holder 134. In particular, one of the four OIS ball holders 134, specifically, the OIS ball holder 134A provided near the Y-axis direction drive unit 50Y is provided on the Y-axis direction power transmission unit 60Y (refer to FIG. 7A). In addition, the OIS ball holder 134 provided on the surface of the light receiving side in the optical axis direction of the X-axis direction power transmission unit 60X may also be provided on the second stage 13.

[0069] A ball holding portion 135 for holding the OIS support portion 41 is formed on the surface (lower surface) on the imaging side in the optical axis direction of the second stage 13 at a position opposite to the OIS ball holding portion 214 of the base 21 in the Z-axis direction. In particular, one of the four OIS ball holding portions 135, specifically, the OIS ball holding portion 135A provided near the X-axis direction drive unit 50X is provided on the X-axis direction power transmission portion 60X (refer to FIG. 7B ). In addition, the OIS ball holding portion 135 provided on the surface on the imaging side in the optical axis direction of the Y-axis direction power transmission portion 60Y may also be provided on the second stage 13. The OIS support portion 41 is clamped by the OIS ball holding portions 214 and 135 of the base 21 and the first stage 12 in a multi-point contact manner. Therefore, the balls constituting the OIS support portion 41 roll stably along the X-axis direction.

[0070] The AF unit 10A includes an AF movable section 11 , a first stage section 12 , an AF driving unit 70 , and an AF support section 15 .

[0071] The first stage portion 12 is a member having a substantially rectangular shape in a planar view as viewed from the optical axis direction, and is formed of, for example, a liquid crystal polymer. The first stage portion 12 has a substantially circular opening 121 at a portion corresponding to the AF movable portion 11 .

[0072] The portion 122 of the first stage 12 corresponding to the X-axis direction drive unit 50X is formed to be recessed radially inward so that the X-axis direction drive unit 50X can be arranged without protruding radially outward. In addition, the portion 123 of the first stage 12 corresponding to the Y-axis direction drive unit 50Y is also formed to be recessed radially inward (hereinafter referred to as "OIS motor fixing portions 122, 123").

[0073] The Y-axis direction driving unit 50Y is fixed to the OIS motor fixing portion 123. With respect to the movement of the OIS movable portion 10 in the Y-axis direction, the first stage portion 12 functions as an active-side member.

[0074] The first stage 12 supports the AF movable part 11 via the AF support part 15 so as to be movable in the optical axis direction. The first stage 12 has an AF ball holding part 124 on which the AF support part 15 is arranged on the inner peripheral surface of the opening 121. In the present embodiment, the AF ball holding part 124 is provided at two diagonal positions among the four corners of the first stage 12 in a planar view. The AF ball holding part 124 extends in the optical axis direction, and is formed into a substantially V-shaped (conical) cross-sectional shape in such a manner that the groove width becomes narrower toward the groove bottom.

[0075] An OIS ball holder (not shown) for holding the OIS support portion 42 is formed on the surface (lower surface) on the imaging side in the optical axis direction of the first stage 12 at a position opposite to the OIS ball holder 134 of the second stage 13 in the Z-axis direction. The OIS support portion 42 is clamped by the OIS ball holders of the first stage 12 and the second stage 13 in a multi-point contact manner. Therefore, the balls constituting the OIS support portion 42 roll stably in the Y-axis direction.

[0076] The first stage 12 has an AF motor fixing portion 125 on which the AF drive unit 70 is arranged on the outer peripheral surface of the opening 121. The AF motor fixing portion 125 is provided at the same diagonal position as the AF ball holding portion 124 among the four corners of the first stage 12 in a planar view. For example, an AF motor fixing metal fitting (not shown) is mounted on the AF motor fixing portion 125, and the AF resonance portion 71 of the AF drive unit 70 is held by the AF motor fixing metal fitting. With respect to the movement of the AF movable portion 11 in the Z-axis direction, the first stage 12 functions as an active side member.

[0077] The first stage 12 is provided with power supply lines for the AF drive unit 70 and the Y-axis direction drive unit 50Y. In the present embodiment, four metal plates 161 are provided in a physically separated state on the surface of the light receiving side in the optical axis direction of the first stage 12. The four metal plates 161 are respectively connected to terminal metal fittings 162 exposed from the four corners of the first stage 12. Power is supplied to the AF drive unit 70 and the Y-axis direction drive unit 50Y via the OIS force applying member 30, the terminal metal fittings 162, and the metal plates 161.

[0078] The AF movable section 11 is a lens holder that holds the lens section 2 (see FIG. 2 ) and moves in the optical axis direction during focusing. The AF movable section 11 is arranged radially inwardly apart from the first stage section 12 (AF fixed section) and is supported by the first stage section 12 via the AF support section 15 in a state where it is biased.

[0079] The AF movable part 11 is made of, for example, polyarylate (PAR), PAR alloy obtained by mixing a plurality of resin materials including PAR, liquid crystal polymer, etc. The AF movable part 11 has a cylindrical lens housing 111. The lens unit 2 is fixed to the inner peripheral surface of the lens housing 111 by, for example, bonding.

[0080] The AF movable part 11 has an AF motor fixing part 112 fixing the AF power transmission part 80 at a position corresponding to the AF drive unit 70 on the outer peripheral surface of the lens housing 111. The AF movable part 11 functions as a passive member in terms of movement of the AF movable part 11 in the Z-axis direction.

[0081] The AF movable part 11 has an AF ball holding part 114 for holding the AF support part 15 at a position corresponding to the AF ball holding part 124 of the first stage part 12 on the outer peripheral surface of the lens housing part 111. In the present embodiment, the AF power transmission part 80 is provided on the outer peripheral surface of the lens housing part 111 of the AF movable part 11 in a manner protruding outward, and the AF ball holding part 114 is formed on the AF power transmission part 80. The AF support part 15 is clamped by the AF ball holding parts 124 and 114 of the first stage part 12 and the AF movable part 11 in a multi-point contact manner. Therefore, the balls constituting the AF support part 15 roll stably in the Z-axis direction.

[0082] The AF support portion 15 supports the AF movable portion 11 in a state of being separated in the radial direction from the first stage portion 12 (AF fixed portion). In the present embodiment, the AF support portion 15 is composed of four balls interposed between the first stage portion 12 and the AF movable portion 11 in a rollable state. In addition, the number of balls constituting the AF support portion 15 can be appropriately changed.

[0083] The X-axis direction driving unit 50X and the Y-axis direction driving unit 50Y are ultrasonic motor type actuators that move the OIS movable part 10 along the X-axis direction and the Y-axis direction. As shown in FIG10A , the X-axis direction driving unit 50X is arranged on the base 21 as the active side component, and is connected to the second stage 13 as the passive side element via the X-axis direction power transmission part 60X. In addition, as shown in FIG10B , the Y-axis direction driving unit 50Y is arranged on the first stage 12 as the active side component, and is connected to the second stage 13 as the passive side element via the Y-axis direction power transmission part 60Y. The X-axis direction driving unit 50X and the X-axis direction power transmission part 60X and the Y-axis direction driving unit 50Y and the Y-axis direction power transmission part 60Y are arranged along mutually orthogonal sides.

[0084] The X-axis direction driving unit 50X and the X-axis direction power transmission unit 60X are arranged to extend along the X-axis, so that the OIS movable unit 10 moves as a whole in the X-axis direction. In this embodiment, the X-axis direction driving unit 50X is fixed to the OIS motor fixing portion 212 of the base 21, and the X-axis direction power transmission unit 60X is fixed to the OIS motor fixing portion 132 of the second stage 13.

[0085] The Y-axis direction driving unit 50Y is arranged to extend along the Y-axis, and moves only the AF unit 10A of the OIS movable unit 10 in the Y-axis direction. In this embodiment, the Y-axis direction driving unit 50Y is fixed to the OIS motor fixing portion 123 of the first stage 12, and the Y-axis direction power transmission unit 60Y is fixed to the OIS motor fixing portion 133 of the second stage 13.

[0086] Hereinafter, the X-axis direction driving unit 50X and the Y-axis direction driving unit 50Y are collectively referred to as “OIS driving units 50X, 50Y”. Also, the X-axis direction power transmission unit 60X and the Y-axis direction power transmission unit 60Y are collectively referred to as “OIS power transmission units 60X, 60Y”.

[0087] The OIS driving units 50X and 50Y each include an OIS resonance portion 51 and an OIS piezoelectric element 52 .

[0088] The OIS piezoelectric element 52 is a plate-shaped element formed of, for example, a ceramic material, and vibrates when a high-frequency voltage is applied. Two OIS piezoelectric elements 52 are arranged so as to sandwich a main body (reference numeral omitted) of the OIS resonance portion 51 .

[0089] The OIS resonance part 51 is formed of a conductive material and resonates in response to the vibration of the OIS piezoelectric element 52. The OIS resonance part 51 may be any metal having predetermined conductivity, shear strength, hardness, specific gravity, Young's modulus, etc., and is preferably made of stainless steel, for example.

[0090] The OIS resonator 51 and the OIS piezoelectric element 52 of the X-axis direction driving unit 50X are electrically connected to wiring (not shown) of the chassis 21. The OIS resonator 51 and the OIS piezoelectric element 52 of the Y-axis direction driving unit 50Y are electrically connected to the metal plate 161 functioning as a power supply line.

[0091] The OIS resonance part 51 has a substantially rectangular main body (symbol omitted) sandwiched by the OIS piezoelectric element 52 and two arms 511 and 512 extending from the upper and lower parts of the main body in the X-axis direction or the Y-axis direction. The two arms 511 and 512 have substantially symmetrical shapes, and their respective free ends abut against the OIS power transmission parts 60X and 60Y, and resonate with the vibration of the OIS piezoelectric element 52 and deform symmetrically.

[0092] In the present embodiment, the two arms 511 and 512 are formed so that the contact surfaces with the OIS power transmission parts 60X and 60Y face inward and are opposite to each other. By causing the OIS resonance part 51 to resonate while the OIS resonance part 51 and the OIS power transmission parts 60X and 60Y are in contact with each other, the vibration motion of the OIS piezoelectric element 52 is converted into the linear motion of the OIS power transmission parts 60X and 60Y.

[0093] The OIS resonance part 51 has at least two resonance frequencies, and deforms in different behaviors with respect to each resonance frequency. In other words, the overall shape of the OIS resonance part 51 is set to deform in different behaviors with respect to the two resonance frequencies. The different behaviors refer to the behaviors of advancing and retreating the OIS power transmission parts 60X and 60Y in the X-axis direction or the Y-axis direction.

[0094] The OIS power transmission parts 60X and 60Y are fixed to the second stage 13 as a passive side component and can move integrally with the second stage 13. The OIS power transmission parts 60X and 60Y are clamped by a pair of arms 511 and 512 of the OIS resonance part 51 in a state where a force is applied. The OIS power transmission parts 60X and 60Y are made of a rigid body and are less likely to deform than the arms 511 and 512. The OIS power transmission parts 60X and 60Y are, for example, block parts made of a ceramic material such as zirconia. In addition, the OIS power transmission parts 60X and 60Y may also be parts in which a coating made of a ceramic material is formed on the surface (at least the surface in contact with the OIS resonance part 51) of a block made of a metal material such as stainless steel.

[0095] In addition, in the OIS power transmission parts 60X and 60Y, the width in the direction clamped by the arms 511 and 512 is larger than the separation width of the front ends of the arms 511 and 512 (the portions abutting against the OIS power transmission parts 60X and 60Y). When the OIS power transmission parts 60X and 60Y are inserted between the arms 511 and 512, the arms 511 and 512 are deformed in an expanding manner, so that a restoring force is generated in the arms 511 and 512. By the restoring force generated by the arms 511 and 512, the OIS power transmission parts 60X and 60Y are held between the arms 511 and 512 in a state of being urged.

[0096] When the OIS power transmission parts 60X and 60Y are composed of two plate-like parts and the OIS power transmission parts 60X and 60Y are forced relative to the arms 511 and 512 by the restoring force generated in the plate-like parts, the contact state between the OIS power transmission parts 60X and 60Y and the arms 511 and 512 changes with the movement of the OIS power transmission parts 60X and 60Y, and there is a concern that the driving performance becomes unstable. In contrast, in the present embodiment, even if the OIS power transmission parts 60X and 60Y move, the contact state between the OIS power transmission parts 60X and 60Y and the arms 511 and 512 does not change, so that stable driving performance can be obtained.

[0097] An OIS ball holder 135A (see FIG. 7B ) that holds the OIS support portion 41 together with the OIS ball holder 214 of the base 21 is provided on the surface of the X-axis direction power transmission portion 60X on the imaging side in the optical axis direction.

[0098] An OIS ball holder 134A (see FIG. 7B ) that holds the OIS support portion 42 together with an OIS ball holder (not shown) of the first stage portion 12 is provided on the surface of the Y-axis direction power transmission portion 60Y on the light receiving side in the optical axis direction.

[0099] Generally, in the optical element driving device 1, the active element (OIS resonance part 51), the passive element (OIS power transmission part 60X, 60Y), etc. are designed so that the moving direction D1 of the movable part (the relative moving direction of the second stage 13 with respect to the base 21 or the first stage 12) and the power transmission direction D2 are consistent. However, due to installation tolerances, for example, the installation angle of the passive element relative to the active element and the installation angle of the movable part relative to the fixed part sometimes deviate. In this case, the power transmission direction D2 is inclined relative to the moving direction D1 of the movable part, and the OIS resonance part 51 and the OIS power transmission part 60X, 60Y are in a state where it is difficult to slide. As a result, there is a concern that the power transmitted to the movable part becomes unstable (refer to FIG. 11B).

[0100] In contrast, in the present embodiment, OIS ball retaining portions 134A and 135A (see FIG. 11A ) are formed in the OIS power transmission portions 60X and 60Y to guide the rolling of the OIS support portions 41 and 42. Furthermore, in the second stage 13 as a passive side component, one of the four OIS support portions 41 is interposed between the base 21 and the X-axis direction power transmission portion 60X, and one of the four OIS support portions 42 is interposed between the first stage 12 and the Y-axis direction power transmission portion 60Y. As a result, the OIS support portions 41 and 42 roll along the power transmission direction D2, so that the moving direction D1 of the movable portion is consistent with the power transmission direction D2 (see FIG. 10A ). Therefore, the sliding of the OIS resonance portion 51 and the OIS power transmission portions 60X and 60Y is maintained, so that the rolling action of the balls of the OIS support portions 41 and 42 can be performed smoothly, and the moving action of the movable portion is stable.

[0101] The AF driving unit 70 is an ultrasonic motor type actuator that moves the AF movable part 11 in the Z-axis direction. As shown in FIG. 12 , the AF driving unit 70 is disposed on the first stage 12 as an active side member and is connected to the AF movable part 11 as a passive element via the AF power transmission part 80 .

[0102] In the present embodiment, two AF drive units 70 are disposed between the AF movable section 11 and the first stage section 12. The AF drive unit 70 is fixed to the AF motor fixing section 125 of the first stage section 12 so that the arms 711 and 712 extend in the Z-axis direction.

[0103] The AF driving unit 70 includes an AF resonance portion 71 and an AF piezoelectric element 72 .

[0104] The AF piezoelectric element 72 is a plate-shaped element formed of, for example, a ceramic material, and vibrates when a high-frequency voltage is applied. Two AF piezoelectric elements 72 are arranged so as to sandwich a main body portion (reference numeral omitted) of the AF resonance portion 71 .

[0105] The AF resonance part 71 is formed of a conductive material and resonates by receiving the vibration of the AF piezoelectric element 72. The AF resonance part 71 may be any metal having predetermined conductivity, shear strength, hardness, specific gravity, Young's modulus, etc. For example, stainless steel is preferred as in the case of the OIS resonance part 51.

[0106] The AF resonance portion 71 and the AF piezoelectric element 72 are electrically connected to a metal plate 161 that functions as a power supply line.

[0107] The AF resonance part 71 has a substantially rectangular main body (symbol omitted) sandwiched by the AF piezoelectric element 72 and two arms 711 and 712 extending from the main body in the Z-axis direction. The two arms 711 and 712 have substantially symmetrical shapes, and their respective free ends abut against the AF power transmission part 80, and resonate with the vibration of the AF piezoelectric element 72 and deform symmetrically.

[0108] The AF resonance part 71 has a substantially rectangular main body (symbol omitted) sandwiched by the AF piezoelectric element 72 and two arms 711 and 712 extending from the main body in the Z-axis direction. The two arms 711 and 712 have substantially symmetrical shapes, and their respective free ends abut against the AF power transmission part 80, and resonate with the vibration of the AF piezoelectric element 72 and deform symmetrically.

[0109] In this embodiment, the two arms 711 and 712 are formed so that the surfaces that abut against the AF power transmission unit 80 face inward and are opposite to each other. By causing the AF resonance unit 71 to resonate while the AF resonance unit 71 and the AF power transmission unit 80 are in abutment with each other, the vibration motion of the AF piezoelectric element 72 is converted into the linear motion of the AF power transmission unit 80.

[0110] The AF resonance portion 71 has at least two resonance frequencies, similarly to the OIS resonance portion 51, and deforms in different behaviors for each resonance frequency. In other words, the overall shape of the AF resonance portion 71 is set so as to deform in different behaviors for the two resonance frequencies.

[0111] The AF power transmission part 80 is fixed to the AF movable part 11 and can move integrally with the AF movable part 11. The AF power transmission part 80 is clamped by the pair of arms 711 and 712 of the AF resonance part 71 in a state where a force is applied. The AF power transmission part 80 is made of a rigid body and is less likely to deform than the arms 711 and 712. The AF power transmission part 80 is, for example, a block component made of a ceramic material such as zirconia. In addition, the AF power transmission part 80 may also be a component in which a coating made of a ceramic material is formed on the surface (at least the surface in contact with the AF resonance part 71) of a block made of a metal material such as stainless steel.

[0112] In addition, in the AF power transmission unit 80, the width in the direction clamped by the arms 711 and 712 is larger than the separation width of the front ends of the arms 711 and 712 (the portion abutting against the AF power transmission unit 80). When the AF power transmission unit 80 is inserted between the arms 711 and 712, the arms 711 and 712 are deformed in an expanding manner, so that a restoring force is generated in the arms 711 and 712. By the restoring force generated by the arms 711 and 712, the AF power transmission unit 80 is maintained between the arms 711 and 712 in a state where a force is applied. Therefore, even if the AF power transmission unit 80 moves, the abutting state of the AF power transmission unit 80 and the arms 711 and 712 does not change, so that stable driving performance can be obtained.

[0113] The AF power transmission part 80 is provided with an AF ball holding part 114 for guiding the rolling of the AF support part 15. In the present embodiment, two AF ball holding parts 114 are provided along the Z-axis direction in a manner sandwiching the AF power transmission part 60. Thus, the rolling motion of the ball of the AF support part 15 can be smoothly performed, and the moving motion of the AF movable part 11 is stable.

[0114] In the optical element driving device 1, when a voltage is applied to the AF driving unit 70, the AF piezoelectric element 72 vibrates, and the AF resonance part 71 deforms in a manner corresponding to the frequency. The AF power transmission part 80 slides in the Z-axis direction by the driving force of the AF driving unit 70. Along with this, the AF movable part 11 moves in the Z-axis direction to focus. Since the AF support part 15 is composed of balls, the AF movable part 11 can move smoothly in the Z-axis direction. In addition, the AF driving unit 70 and the AF power transmission part 80 only abut in a state where a force is applied, so only by increasing the abutting part in the Z-axis direction, the moving stroke of the AF movable part 11 can be easily increased without damaging the low height of the optical element driving device 1.

[0115] In the optical element driving device 1, when a voltage is applied to the OIS driving units 50X and 50Y, the OIS piezoelectric element 52 vibrates, and the OIS resonance part 51 deforms in accordance with the frequency. The OIS power transmission parts 60X and 60Y slide in the X-axis direction or the Y-axis direction by the driving force of the OIS driving units 50X and 50Y. Along with this, the OIS movable part 10 moves in the X-axis direction or the Y-axis direction to perform shake correction. Since the OIS support parts 41 and 42 are composed of balls, the OIS movable part 10 can move smoothly in the X-axis direction or the Y-axis direction.

[0116] Specifically, when the X-axis direction driving unit 50X is driven and the X-axis direction power transmission unit 60X moves in the X-axis direction, power is transmitted from the base 21 equipped with the X-axis direction driving unit 50X to the second stage 13. At this time, the OIS support portion 42 clamped by the first stage 12 and the second stage 13 cannot roll in the X-axis direction, so the position of the first stage 12 relative to the second stage 13 in the X-axis direction is maintained. On the other hand, the OIS support portion 41 clamped by the second stage 13 and the base 21 can roll in the X-axis direction, so the second stage 13 moves in the X-axis direction relative to the base 21. The first stage 12 also moves in the X-axis direction following the second stage 13.

[0117] In addition, when the Y-axis direction driving unit 50Y is driven and the Y-axis direction power transmission unit 60Y moves in the Y-axis direction, power is transmitted from the first stage 12 on which the Y-axis direction driving unit 50Y is arranged to the second stage 13. At this time, the OIS support part 41 clamped by the second stage 13 and the base 21 cannot roll in the Y-axis direction, so the position of the second stage 13 relative to the base 21 in the X-axis direction is maintained. On the other hand, the OIS support part 42 clamped by the first stage 12 and the second stage 13 can roll in the Y-axis direction, so the first stage 12 moves in the Y-axis direction relative to the second stage 13.

[0118] In the optical element driving device 1, for example, based on a detection signal indicating angular shake from a shake detection unit (e.g., a gyro sensor, not shown), the energization voltage to the X-axis direction driving unit 50X and the Y-axis direction driving unit 50Y is controlled to cancel the angular shake of the camera module A. At this time, the detection result of the position detection unit may be fed back to control the translational movement of the OIS movable unit 10.

[0119] As described above, the optical element driving device 1 according to the embodiment includes the following characteristic matters individually or in appropriate combination.

[0120] That is, regarding the movement of the OIS movable portion 10 in the X-axis direction, the optical element driving device 1 includes: a base 21 (fixed portion), a second stage 13 (movable portion) including a lens portion 2 (optical element) and capable of moving relative to the base 21 via an OIS support portion 41 (rolling element), an ultrasonic motor type X-axis direction driving unit 50X (driving portion) arranged on the base 21 (an active side component composed of either the fixed portion or the movable portion) and moving the second stage 13 relative to the base 21, and an X-axis direction power transmission portion 60X that connects the second stage 13 (a passive side component composed of either the other of the fixed portion and the movable portion) and the X-axis direction driving unit 50X and transmits the power of the X-axis direction driving unit 50X to the second stage 13. The X-axis direction driving unit 50X includes an OIS resonance part 51, which includes a pair of vibrating arms 511 and 512, and the X-axis direction power transmission part 60X includes an OIS ball holding part 135A (guide part) that guides the OIS support part 41, and is clamped in a state of being forced by the pair of arms 511 and 512. As a result, the movement of the OIS movable part 10 including the second stage part 13 relative to the OIS fixed part 20 including the base 21 in the X-axis direction is stable, and the driving performance can be improved, and the reliability of the optical element driving device 1, the camera module A, and the smartphone M (camera-mounted device) is improved.

[0121] In addition, regarding the movement of the OIS movable portion 10 in the Y-axis direction, the optical element driving device 1 includes: a second stage 13 (fixed portion), a first stage 12 (movable portion) including a lens portion 2 (optical element) and capable of moving relative to the second stage 13 via an OIS support portion 42 (rolling element), an ultrasonic motor type Y-axis direction driving unit 50Y (driving portion) arranged on the first stage 12 (an active side component composed of either the fixed portion or the movable portion) and moving the first stage 12 relative to the second stage 13, and a Y-axis direction power transmission portion 60Y that connects the second stage 13 (a passive side component composed of either the other of the fixed portion and the movable portion) and the Y-axis direction driving unit 50Y and transmits the power of the Y-axis direction driving unit 50Y to the second stage 13. The Y-axis direction driving unit 50Y has an OIS resonance part 51, and the OIS resonance part 51 has a pair of vibrating arms 511 and 512. The Y-axis direction power transmission part 60Y has an OIS ball holding part 134A (guide part) that guides the OIS support part 42, and is clamped in a state of being forced by the pair of arms 511 and 512. As a result, the movement of the OIS movable part 10 including the first stage part 12 relative to the OIS fixed part 20 including the second stage part 13 in the Y-axis direction is stable, and the driving performance can be improved, and the reliability of the optical element driving device 1, the camera module A, and the smartphone M (camera-mounted device) is improved.

[0122] In addition, regarding the movement of the AF movable part 11 in the Z-axis direction, the optical element driving device 1 includes: a first stage 12 (fixed part); an AF movable part 11 (movable part) including a lens part 2 (optical element) and capable of moving relative to the first stage 12 via an AF support part 15 (rolling body); an ultrasonic motor type AF driving unit 70 arranged on the first stage 12 (an active side component composed of either the fixed part or the movable part) and moving the AF movable part 11 relative to the first stage 12; and an AF power transmission part 80 that connects the AF movable part 11 (a passive side component composed of either the other of the fixed part and the movable part) and the AF driving unit 70 and transmits the power of the AF driving unit 70 to the AF movable part 11. The AF driving unit 70 includes an AF resonance portion 71 having a pair of vibrating arms 711 and 712, and the AF power transmission portion 80 includes an AF ball holding portion 114 (guide portion) for guiding the AF support portion 15, and is clamped in a state of being urged by the pair of arms 711 and 712. As a result, the movement of the AF movable portion 11 in the Z-axis direction relative to the first stage portion 12 is stabilized, the driving performance can be improved, and the reliability of the optical element driving device 1, the camera module A, and the smartphone M (camera-mounted device) is improved.

[0123] The OIS power transmission parts 60X, 60Y and the AF power transmission part 80 are formed of a material different from that of the second table part 13 and the AF movable part 11 (passive side parts), and are fixed so as not to be displaceable relative to the second table part 13 and the AF movable part 11. Thus, the second table part 13 and the AF movable part 11, which are passive side parts, can be easily given a function as a power transmission part while suppressing an increase in weight, and appropriate driving performance can be ensured.

[0124] The X-axis direction power transmission part 60X and the Y-axis direction power transmission part 60Y are less likely to deform than the pair of arms 511 and 512, and the width of the X-axis direction power transmission part 60X and the Y-axis direction power transmission part 60Y in the direction clamped by the pair of arms 511 and 512 is larger than the separation width of the pair of arms 511 and 512. Therefore, even if the X-axis direction power transmission part 60X and the Y-axis direction power transmission part 60Y move, the contact state between the X-axis direction power transmission part 60X and the Y-axis direction power transmission part 60Y and the arms 511 and 512 is maintained. Compared with the case where the X-axis direction power transmission part 60X and the Y-axis direction power transmission part 60Y are forced relative to the arms 511 and 512 by the restoring force generated in the plate-like member, the driving performance is improved.

[0125] In addition, the AF power transmission part 80 is less likely to deform than the pair of arms 711 and 712, and the width of the AF power transmission part 80 in the direction clamped by the pair of arms 711 and 712 is larger than the separation width of the pair of arms 711 and 712. Therefore, even if the AF power transmission part 80 moves, the contact state between the AF power transmission part 80 and the arms 711 and 712 is maintained. Compared with the case where the AF power transmission part 80 is forced relative to the arms 711 and 712 by the restoring force generated in the plate-like member, the driving performance is improved.

[0126] As mentioned above, the invention made by the present inventors has been specifically described based on the embodiments. However, the present invention is not limited to the above-mentioned embodiments, and can be modified within the scope not departing from the gist thereof.

[0127] For example, in an embodiment, the characteristic power transmission structure of the present invention is applied to the X-axis direction drive unit 50X, the Y-axis direction drive unit 50Y and the AF drive unit 70, but it can also be applied to only any one of the X-axis direction drive unit 50X, the Y-axis direction drive unit 50Y and the AF drive unit 70.

[0128] In the embodiment, the X-axis direction drive unit 50X, the Y-axis direction drive unit 50Y, and the AF drive unit 70 are all composed of ultrasonic motor type actuators, but the drive unit that does not apply the characteristic power transmission structure of the present invention may not be an ultrasonic motor type.

[0129] Furthermore, in the embodiment, the optical element driving device 1 having the AF function and the OIS function is described as an example, but the present invention can also be applied to an optical element driving device having either the AF function or the OIS function.

[0130] 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 explanation, 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 mobile phone with a camera, a notebook computer, a tablet terminal, a portable game console, a web camera, and a vehicle-mounted device with a camera (for example, a rear monitor device, a driving recorder device). In addition, transportation equipment includes, for example, a car and a drone (unmanned aerial vehicle).

[0131] Fig. 13A and Fig. 13B are diagrams showing a car V equipped with a vehicle camera module VC (Vehicle Camera) as a camera mounting device. Fig. 13A is a front view of the car V, and Fig. 13B is a rear perspective view of the car V. The car V is equipped with the camera module A described in the embodiment as the vehicle camera module VC. As shown in Fig. 13A and Fig. 13B, the vehicle camera module VC is installed on the front windshield facing forward, or on the rear door facing backward. The vehicle camera module VC is used as a vehicle camera module for rear monitoring, driving recorder, collision avoidance control, automatic driving control, etc.

[0132] Furthermore, in the embodiment, the optical element driving device 1 that drives the lens unit 2 as an optical element has been described. However, the optical element to be driven may be an optical element other than a lens such as a reflector or a prism.

[0133] 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 is intended to include all modifications within the scope of the claims and the meaning equivalent to the claims.

[0134] The disclosed contents of the specification, drawings and abstract contained in the Japanese application No. 2022-138102 filed on August 31, 2022 are all cited in this application.

[0135] Explanation of symbols

[0136] 1—optical element driving device, 10—OIS movable part (movable part), 11—AF movable part (movable part), 114—AF ball holding part (guide part), 12—first stage part (active side part), 13—second stage part (passive side part), 134A, 135A—OIS ball holding part (guide part), 15—AF supporting part (rolling body), 20—OIS fixed part (fixed part), 21—base (active side part), 41, 42—OIS supporting part (rolling body), 50X—X-axis direction driving unit (driving part), 50Y—Y-axis direction driving unit (driving part), 51—OIS resonance part (resonance part), 60X—X-axis direction power transmission part, 60Y—Y-axis direction power transmission part, 70—AF driving unit (driving part), 80—AF power transmission part, A—camera module, M—smartphone (camera mounting device).

Claims

1. An optical element driving device, characterized in that: have: Fixed part; a movable part including an optical element and capable of moving relative to the fixed part via a rolling body; an ultrasonic motor type driving section, which is disposed on an active side member formed by either the fixed section or the movable section, and moves the movable section relative to the fixed section; as well as a power transmission part that connects a passive side member formed by the other of the fixed part and the movable part and the driving part, and transmits the power of the driving part to the passive side member, The driving part has a resonance part having a pair of vibrating arms. The power transmission portion includes a guide portion for guiding the rolling element, and is sandwiched by the pair of arms in a biased state.

2. The optical element driving device according to claim 1, characterized in that: The power transmission portion is formed of a material different from that of the passive-side member, and is fixed to the passive-side member so as to be non-displaceable.

3. The optical element driving device according to claim 1 or 2, characterized in that: The power transmission part is less likely to deform than the pair of arms. The width of the power transmission portion in the direction sandwiched by the pair of arms is larger than the separation width of the pair of arms.

4. A camera module, characterized in that: have: The optical element driving device according to claim 1; an optical element mounted on the movable portion; and The imaging unit captures the subject image formed by the optical element.

5. A camera-mounted device, which is an information device or a transport device, characterized in that: have: The camera module of claim 4; and The image processing unit processes the image information obtained by the camera module.

Images