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

Abstract

The invention provides a reliable optical element driving device, a camera module, and a camera mounting device. The optical element driving device, the camera module, and the camera mounting device are capable of suppressing deterioration of driving performance over time caused by wear of an active element or a passive element. The optical element driving device includes: a fixed portion; a movable part disposed at a distance from the fixed part; a support part that supports the movable part on the fixed part; and a drive unit (30) that includes an ultrasonic motor having a piezoelectric element (32) and an active element (31) that resonates with the vibration of the piezoelectric element (32), and a passive element (34) that is in contact with the active element (31) and moves relative to the active element (31) in a biased state, and that moves the movable part relative to the fixed part. The passive-side contact portion (343) of the passive element (34) is formed of a ceramic material having a higher hardness than the active-side contact portion (312) of the active element (31).

Description

[0001] This application is a divisional application of the Chinese invention patent application with application date of September 28, 2021, application number 202180078024.7, invention name “Optical element driving device, camera module and camera mounting device”, and applicant being Mitsumi Electric Co., Ltd. Technical Field

[0002] The invention relates to an optical element driving device, a camera module and a camera mounting device. Background Art

[0003] Generally, a small camera module is mounted in a portable terminal such as a smartphone. Such a camera module has an optical element 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 photographing to reduce image blur (for example, Patent Document 1).

[0004] 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 along 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.

[0005] Prior art literature

[0006] Patent Literature

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

[0008] Problem that the invention aims to solve

[0009] However, in the ultrasonic motor type drive unit, the active element composed of the resonance part and the passive element that moves relative to the active element are in contact with each other under the state of being applied force, and the two slide when driving, so the driving performance may be reduced over time due to wear. In particular, a certain degree of friction is required between the active element and the passive element to enable the passive element to move, but if the friction increases, the contact part is easy to wear, so it is important to balance these aspects.

[0010] An object of the present invention is to provide a reliable optical element driving device, a camera module and a camera mounting device, which can suppress the time-dependent degradation of driving performance caused by wear of active elements or passive elements.

[0011] Solutions to the problem

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

[0013] Fixed part;

[0014] A movable part, arranged to be spaced apart from the fixed part;

[0015] a supporting portion, supporting the movable portion on the fixed portion; and

[0016] The driving unit includes an ultrasonic motor having a piezoelectric element and an active element that resonates with the vibration of the piezoelectric element, and a passive element that contacts the active element and moves relative to the active element when a force is applied, and the driving unit moves the movable part relative to the fixed part.

[0017] The passive-side contact portion of the passive element is formed of a ceramic material having a higher hardness than the active-side contact portion of the active element.

[0018] The optical element driving device of the present invention comprises:

[0019] Fixed part;

[0020] A movable part, arranged to be spaced apart from the fixed part;

[0021] a supporting portion, supporting the movable portion on the fixed portion;

[0022] a driving unit including an ultrasonic motor having a piezoelectric element and an active element that resonates with the vibration of the piezoelectric element, and a passive element that contacts the active element and moves relative to the active element in a state where a force is applied, wherein the driving unit moves the movable part relative to the fixed part; and

[0023] The surrounding portion surrounds at least a portion of a contact area between the passive-side contact portion of the passive element and the active-side contact portion of the active element.

[0024] The camera module of the present invention comprises:

[0025] The above-mentioned optical element driving device;

[0026] an optical element mounted on the movable portion; and

[0027] The imaging unit captures the image of the object formed by the optical element.

[0028] The camera-mounted device of the present invention is an information device or a transportation device, and the camera-mounted device comprises:

[0029] The camera module mentioned above; and

[0030] The image processing unit processes the image information obtained by the camera module.

[0031] Effects of the Invention

[0032] According to the present invention, it is possible to provide a reliable optical element driving device, a camera module, and a camera-mounted device capable of suppressing the deterioration in driving performance over time due to wear of active elements or passive elements. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1A , Figure 1B This is a diagram showing a smartphone equipped with a camera module according to an embodiment of the present invention.

[0034] Figure 2 This is a stereoscopic view of the camera module.

[0035] Figure 3 This is a perspective view of the appearance of the optical element driving device.

[0036] Figure 4 This is a perspective view of the appearance of the optical element driving device.

[0037] Figure 5 It is an exploded perspective view of the optical element driving device.

[0038] Figure 6 It is an exploded perspective view of the optical element driving device.

[0039] Figure 7 It is a top view showing the wiring structure of the chassis.

[0040] Fig. 8A , Figure 8B It is a three-dimensional diagram of the OIS driver unit.

[0041] Figures 9A to 9C It is an enlarged view showing the contact portion between the OIS resonator and the OIS plate.

[0042] Fig.10 This is an exploded perspective view of the OIS movable part.

[0043] Fig.11 This is an exploded perspective view of the OIS movable part.

[0044] Fig.12This is an exploded perspective view of the OIS movable part.

[0045] Fig.13A , Fig. 13B This is a perspective view of the AF drive unit.

[0046] Fig.14A , Fig. 14B It is a diagram showing a holding structure of an AF drive unit.

[0047] Fig.15 This is a plan view of the OIS movable part as viewed from the light receiving side in the optical axis direction.

[0048] Fig.16A , Fig. 16B It is a top view of the AF movable part and the first stage part.

[0049] Fig.17A , Fig. 17B 1 and 2 are cross-sectional views and longitudinal cross-sectional views of the peripheral portion of the AF drive unit 14 .

[0050] Fig.18A , Fig.18B It is an enlarged view showing the arrangement of the AF support section.

[0051] Fig.19A , Fig.19B FIG. 1 is a diagram showing a car as a camera mounting device on which a vehicle-mounted camera module is mounted. DETAILED DESCRIPTION

[0052] Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

[0053] 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.

[0054] The smartphone M has a dual-lens camera consisting of two rear cameras OC1 and OC2. In this embodiment, the camera module A is applied to the rear cameras OC1 and OC2.

[0055] The camera module A has an AF function and an OIS function, and can automatically focus on the subject when shooting, and can optically correct the shake (vibration) generated during shooting to shoot an unblurred image.

[0056] Figure 2 This is a perspective view of the appearance of camera module A. Figure 3 and Figure 4It is a perspective view of the appearance of the optical element driving device 1 according to the embodiment. Figure 4 Show that Figure 3 The state after rotating 180° around the Z axis. Figure 2 to Figure 4 As shown, in the embodiment, the description is made using the orthogonal coordinate system (X, Y, Z). In the drawings described later, the same orthogonal coordinate system (X, Y, Z) is also used for representation.

[0057] For example, the camera module A is mounted as follows: when the smartphone M is actually shooting, the X direction is the up-down direction (or left-right direction), the Y direction is the left-right direction (or up-down direction), and the Z direction is the front-back direction. That is, the Z direction is the optical axis direction, the upper side (+Z side) in the figure is the light receiving side in the optical axis direction, and the lower side (-Z side) is the imaging side in the optical axis direction. In addition, the X direction and the Y direction orthogonal to the Z axis are called "directions orthogonal to the optical axis", and the XY plane is called "plane orthogonal to the optical axis".

[0058] like Figure 2 to Figure 4 As shown, the camera module A includes an optical element driving device 1 that realizes 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 that captures an image of a subject formed by the lens unit 2. That is, the optical element driving device 1 is a so-called lens driving device that drives the lens unit 2 as an optical element.

[0059] The camera unit 3 is arranged on the imaging side of the optical axis direction of the optical element driving device 1. The camera unit 3 has, for example, an image sensor substrate 301, an image sensor 302 mounted on the image sensor substrate 301, and a control unit 303. The image sensor 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 image of the object imaged by the lens unit 2. The control unit 303 is composed of, for example, a control IC, and performs drive 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 thereto. It should be noted that the control unit 303 can be provided on the image sensor substrate 301, or on a camera-mounted device (a smartphone M in the embodiment) equipped with a camera module A.

[0060] The outer side of the optical element driving device 1 is covered by a cover 24. The cover 24 is a quadrangular cylinder with a cover, and its top view shape observed along the optical axis direction is rectangular. In the embodiment, the top view shape of the cover 24 is square. The cover 24 has a substantially circular opening 241 on its upper surface. The lens portion 2 faces outward from the opening 241 of the cover 24, and is configured to protrude to a position closer to the light receiving side than the opening surface of the cover 24 as it moves in the optical axis direction. 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 (see Figure 5 ).

[0061] Figure 5 , Figure 6 It is an exploded perspective view of the optical element driving device 1 according to the embodiment. Figure 6 Show that Figure 5 The state after rotating 180° around the Z axis. Figure 5 2 shows a state where the OIS driving unit 30 and the sensor substrate 22 are mounted on the base 21. Figure 6 The state where the OIS driving unit 30 and the sensor substrate 22 are removed from the chassis 21 is shown.

[0062] like Figure 5 , Figure 6 As shown, in this embodiment, the optical element driving device 1 includes an OIS movable part 10, an OIS fixed part 20, an OIS driving unit 30, and an OIS supporting part 40. The OIS driving unit 30 includes an X-direction driving unit 30X and a Y-direction driving unit 30Y.

[0063] The OIS movable part 10 is a part that moves in a plane perpendicular to the optical axis during shake correction. The OIS movable part 10 includes an AF unit, a second stage 13, and X-direction reference balls 42A to 42D (see Fig.10 The AF unit includes an AF movable section 11, a first stage section 12, an AF driving unit 14, and an AF support section 15 (see Figure 10 to Figure 12 ).

[0064] 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.

[0065] 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 the OIS urging member 50. The OIS urging member 50 is arranged, for example, at the four corners of the optical element driving device 1 when viewed from above.

[0066] In this embodiment, regarding the movement in the Y direction, the entire OIS movable part 10 including the AF unit moves as a movable body. On the other hand, regarding the movement in the X direction, only the AF unit moves as a movable body. That is, regarding the movement in the X direction, the second stage 13 and the base 21 together constitute the OIS fixed part 20, and the X-direction reference balls 42A to 42C function as the OIS support part 40.

[0067] The base 21 is formed of a molding material such as polyarylate (PAR), a PAR alloy (PAR Alloy, for example, PAR / PC) obtained by mixing a plurality of resin materials including PAR, or a liquid crystal polymer. The base 21 is a rectangular member in a plan view and has a circular opening 211 in the center.

[0068] The base 21 includes a first base portion 212 and a second base portion 213 that form a main surface of the base 21. The second base portion 213 and the protruding portions 112A to 112D of the AF movable portion 11 and the AF motor fixing portion 125 of the first stage portion 12 (see Fig.11 ) are provided correspondingly. The second base portion 213 is formed to be larger than the protrusions 112A to 112D and the AF motor fixing portion 125 when viewed from above, so as to avoid interference during shake correction. In the area of ​​the second base portion 213 where the terminal metal fitting 23B is arranged, the sensor substrate 22 is arranged in a partially exposed manner. The second base portion 213 is formed to be recessed relative to the first base portion 212, thereby ensuring the moving stroke of the AF movable portion 11 and realizing a low height of the optical element driving device 1.

[0069] In the present embodiment, the sensor substrate 22 is provided in an area where the AF drive unit 14 and the OIS drive unit 30 are not provided, that is, an area corresponding to one side (fourth side) of the rectangular shape of the base 21 when viewed from above. Thus, the power supply lines and signal lines for the magnetic sensors 25X, 25Y, and 25Z can be gathered together, thereby simplifying the wiring structure in the base 21 (see FIG. Figure 7 ).

[0070] The chassis 21 has an OIS motor fixing portion 215 where the Y-direction drive unit 30Y is disposed. The OIS motor fixing portion 215 is provided at a corner of the chassis 21, for example, and is formed to protrude from the first chassis portion 212 toward the light receiving side in the optical axis direction, and has a shape capable of holding the Y-direction drive unit 30Y.

[0071] Terminal metal fittings 23A to 23C are arranged on the base 21, for example, by insert molding. The terminal metal fitting 23A includes power supply lines for the AF drive unit 14 and the X-direction drive unit 30X. The terminal metal fitting 23A is exposed from the four corners of the base 21, for example, and is electrically connected to the OIS force application component 50. The AF drive unit 14 and the X-direction drive unit 30X are powered via the OIS force application component 50. The terminal metal fitting 23B includes power supply lines (for example, 4) and signal lines (for example, 6) for the magnetic sensors 25X, 25Y, and 25Z. The terminal metal fitting 23B is electrically connected to the wiring (not shown) formed on the sensor substrate 22. The terminal metal fitting 23C includes a power supply line for the Y-direction drive unit 30Y.

[0072] In addition, the base 21 has Y-direction reference ball holding portions 217A to 217C, and the Y-direction reference balls 41A to 41C constituting the OIS support portion 40 are arranged in the Y-direction reference ball holding portions 217A to 217C. The Y-direction reference ball holding portions 217A to 217C are formed as rectangular depressions extending in the Y direction. The Y-direction reference ball holding portions 217A to 217C are formed in a substantially V-shaped (tapered) cross-sectional shape so that the groove width narrows toward the bottom surface side.

[0073] In this embodiment, the Y-direction reference ball retaining portions 217A and 217B are arranged on the side (third side) of the base 21 where the Y-direction driving unit 30Y is configured, and the Y-direction reference ball retaining portion 217C is arranged on the side (fourth side) where the sensor substrate 22 is configured. The OIS movable portion 10 (second table portion 13) is supported at three points by the Y-direction reference balls 41A to 41C arranged on the Y-direction reference ball retaining portions 217A to 217C.

[0074] The sensor substrate 22 has wiring (not shown) including power supply lines and signal lines for the magnetic sensors 25X, 25Y, and 25Z. The magnetic sensors 25X, 25Y, and 25Z are mounted on the sensor substrate 22. The magnetic sensors 25X, 25Y, and 25Z are composed of, for example, Hall elements or TMR (Tunnel Magneto Resistance) sensors, and are electrically connected to the terminal metal fitting 23B via wiring (not shown) formed on the sensor substrate 22. In addition, in the sensor substrate 22, an opening 221 is provided in a portion corresponding to the Y-direction reference ball retaining portion 217C.

[0075] On the first stage 12 of the OIS movable unit 10, magnets 16X and 16Y are arranged at positions facing the magnetic sensors 25X and 25Y (see Fig.12The position of the OIS movable part 10 in the X direction and the Y direction is detected by the position detection part composed of the magnetic sensors 25X and 25Y and the magnets 16X and 16Y.

[0076] In addition, a magnet 16Z is disposed on the AF movable section 11 of the OIS movable section 10 at a position facing the magnetic sensor 25Z (see Fig.12 ). The position of the AF movable part 11 in the Z direction is detected by a position detection unit composed of a magnetic sensor 25Z and a magnet 16Z. It should be noted that, instead of the magnets 16X, 16Y, 16Z and the magnetic sensors 25X, 25Y, 25Z, an optical sensor such as a photo reflector may be used to detect the position of the OIS movable part 10 in the X direction and the Y direction and the position of the AF movable part 11 in the Z direction.

[0077] The OIS urging member 50 is composed of, for example, a helical tension spring, and connects the OIS movable portion 10 and the OIS fixed portion 20. In the present embodiment, one end of the OIS urging member 50 is connected to the terminal metal fitting 23A of the base 21, and the other end is connected to the wirings 17A and 17B of the first stage 12. That is, in the present embodiment, the OIS urging member 50 functions as a power supply line to the AF drive unit 14 and the X-direction drive unit 30X.

[0078] In addition, the OIS force applying member 50 is subjected to a tensile load when the OIS movable part 10 and the OIS fixed part 20 are connected, and acts in a manner that the OIS movable part 10 and the OIS fixed part 20 are brought closer to each other. That is, the OIS movable part 10 is held movable in the XY plane in a state where the OIS force applying member 50 applies force in the optical axis direction (in a state where the OIS movable part 10 is pressed against the base 21). Thus, the OIS movable part 10 can be held in a stable state without vibration.

[0079] The OIS force member 50 may also be provided with a shock-absorbing material (not shown) for suppressing vibration. The shock-absorbing material is, for example, configured in a manner covering the entire OIS force member 50. The shock-absorbing material is, for example, formed in a state where the spring is stretched after the OIS force member 50 is assembled. The shock-absorbing material is formed of a gel-like resin material having a viscosity and elasticity that allows it to be retained in the hollow portion of the OIS force member 50 and does not affect the tracking performance of the OIS movable portion 10 when it moves in the XY plane. As the shock-absorbing material, for example, a silicone material or a silicone-based shock-absorbing material may be applied. It should be noted that the shock-absorbing material may be configured to fill only the gap between adjacent spring elements in the axial direction, or to fill only the interior (hollow portion) of the coil spring.

[0080] By configuring the vibration-damping material in the OIS urging member 50, the vibration of the OIS urging member 50 is effectively damped in a short time, and the air vibration accompanying the vibration of the OIS urging member 50 is also suppressed. Therefore, the generation of driving sound can be suppressed, and the quiet performance of the optical element driving device 1 is significantly improved.

[0081] The OIS support part 40 supports the OIS movable part 10 on the OIS fixed part 20 in a state where the OIS movable part 10 is spaced apart from the OIS fixed part 20 in the optical axis direction. In the present embodiment, the OIS support part 40 includes three Y-direction reference balls 41A to 41C interposed between the OIS movable part 10 (second stage 13) and the base 21.

[0082] In addition, the OIS support portion 40 includes four X-direction reference balls 42A to 42D (see FIG. 4 ) interposed between the first stage 12 and the second stage 13 in the OIS movable portion 10. Fig.10 wait).

[0083] In this embodiment, by limiting the rolling directions of the Y-direction reference balls 41A to 41C and the X-direction reference balls 42A to 42D (a total of 7), the OIS movable part 10 can be moved with good accuracy in the XY plane. It should be noted that the number of the Y-direction reference balls and the X-direction reference balls constituting the OIS support part 40 can be appropriately changed.

[0084] The OIS driving unit 30 is an actuator that moves the OIS movable part 10 in the X direction and the Y direction. Specifically, the OIS driving unit 30 includes an X-direction driving unit 30X that moves the OIS movable part 10 (only the AF unit) in the X direction and a Y-direction driving unit 30Y that moves the entire OIS movable part 10 in the Y direction.

[0085] The X-direction driving unit 30X is fixed to the OIS motor fixing portion 124 (see Fig.11 ). The Y-direction drive unit 30Y is fixed to the OIS motor fixing portion 215 of the base 21 in a manner extending along the Y direction. That is, the X-direction drive unit 30X and the Y-direction drive unit 30Y are arranged along sides orthogonal to each other. As described later, the X-direction drive unit 30X and the Y-direction drive unit 30Y include an ultrasonic motor USM1.

[0086] The structure of the OIS driving unit 30 is as follows Fig. 8A , Figure 8B shown. Fig. 8A 2 shows the state after the components of the OIS driving unit 30 are assembled. Figure 8B 2 shows the state in which the components of the OIS driving unit 30 are disassembled. Fig. 8A , Figure 8B The Y-direction driving unit 30Y is shown in FIG. 1 , but the main structure of the X-direction driving unit 30X is the same as that of the Y-direction driving unit 30Y, so Fig. 8A , Figure 8B Specifically, the main structure is a structure other than the shape of the OIS electrode 33 , as viewed in the figure showing the OIS driving unit 30 .

[0087] like Fig. 8A , Figure 8B As shown, the OIS driving unit 30 has an OIS ultrasonic motor USM1 and an OIS power transmission unit 34. The OIS ultrasonic motor USM1 is composed of an OIS resonance unit 31, an OIS piezoelectric element 32 and an OIS electrode 33. The driving force of the OIS ultrasonic motor USM1 is transmitted to the second stage 13 via the OIS power transmission unit 34. Specifically, the X-direction driving unit 30X is connected to the second stage 13 via the OIS power transmission unit 34, and the Y-direction driving unit 30Y is connected to the second stage 13 via the OIS power transmission unit 34. That is, in the OIS driving unit 30, the OIS resonance unit 31 constitutes an active element, and the OIS power transmission unit 34 constitutes a passive element.

[0088] 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. Two OIS piezoelectric elements 32 are arranged so as to sandwich the body portion 311 of the OIS resonance part 31 .

[0089] The OIS electrode 33 sandwiches the OIS resonance part 31 and the OIS piezoelectric element 32, and applies a voltage to the OIS piezoelectric element 32. The OIS electrode 33 of the X-direction drive unit 30X is electrically connected to the wiring 17A of the first stage 12, and the OIS electrode 33 of the Y-direction drive unit 30Y is electrically connected to the terminal metal fitting 23C of the base 21.

[0090] 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 this embodiment, the OIS resonance part 31 has: a substantially rectangular body 311 sandwiched by the OIS piezoelectric element 32, two arm parts 312 extending from the upper and lower parts of the body 311 in the X direction or the Y direction, a protrusion 313 extending from the center of the body 311 in the X direction or the Y direction, and a current-carrying part 314 extending from the center of the body 311 to the side opposite to the protrusion 313.

[0091] The two arms 312 have symmetrical shapes, and their free ends abut against the OIS power transmission part 34, and deform symmetrically in resonance with the vibration of the OIS piezoelectric element 32. In this embodiment, the two arms 312 are formed so that the abutting surfaces abutting against the OIS plate 341 of the OIS power transmission part 34 face inward and are opposite to each other.

[0092] The conducting portion 314 of the X-direction drive unit 30X is electrically connected to the wiring 17A of the first stage unit 12 , and the conducting portion 314 of the Y-direction drive unit 30Y is electrically connected to the terminal metal fitting 23C of the base 21 .

[0093] The OIS resonance part 31 can be any metal having specified conductivity, shear strength, hardness, specific gravity, Young's modulus, etc. For example, stainless steel is suitable. The Vickers hardness of stainless steel is 180 to 400 HV. The OIS resonance part 31 is formed, for example, by laser processing, etching or stamping of a metal plate. It should be noted that at the front end (active side contact part) of the arm part 312 that contacts the OIS plate 341, a coating such as hard plating or painting can be provided, or a surface treatment other than a coating can be applied.

[0094] The OIS piezoelectric element 32 is attached to the body 311 of the OIS resonance part 31 in the thickness direction and is sandwiched by the OIS electrode 33 so that they are electrically connected to each other. For example, one of the power supply paths is connected to the OIS electrode 33, and the other is connected to the power supply part 314 of the OIS resonance part 31, thereby applying a voltage to the OIS piezoelectric element 32 to generate vibration.

[0095] 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 34 forward in the X direction or the Y direction and the motion of moving backward in the X direction or the Y direction.

[0096] The OIS power transmission part 34 is a clamping guide extending in one direction, one end of which is connected to the arm part 312 of the OIS resonance part 31, and the other end of which is connected to the second stage 13. The OIS power transmission part 34 has a stage connection member 342 connected to the first stage 12 or the second stage 13, and a plate-shaped OIS plate 341 connecting the OIS ultrasonic motor USM1 (OIS resonance part 31) and the stage connection member 342.

[0097] Two OIS plates 341 are provided, and the two OIS plates 341 are respectively in contact with the two arm portions 312 of the OIS resonator 31. The two OIS plates 341 are arranged to be substantially parallel to each other. In the OIS plate 341, the surface on the side in contact with the OIS resonator 31 is referred to as the "first surface", and the surface on the opposite side is referred to as the "second surface". The OIS plates 341 are arranged so that the second surfaces are opposite to each other.

[0098] One end 341b of the OIS plate 341 is slidably abutted against the free end of the arm 312 of the OIS resonator 31 (hereinafter referred to as "OIS motor abutment portion 341b"). The other end (not shown) of the OIS plate 341 is inserted into and fixed to the table connection member 342. In the OIS plate 341, the portion extending from the OIS motor abutment portion 341b to the other end is referred to as "extension portion 341a".

[0099] Preferably, the OIS plate 341 has a rigidity equal to or greater than that of the OIS resonant portion 31, and for example, stainless steel is suitable. Thus, the OIS plate 341 can be endowed with self-restoring characteristics and act as a spring, so that the desired friction force can be easily generated between the OIS resonant portion 31 and the OIS plate 341. It should be noted that the steel type of the stainless steel forming the OIS resonant portion 31 and the stainless steel forming the OIS plate 341 can be the same or different. For example, the appropriate steel type is selected in consideration of the transmission of force from the OIS resonant portion 31 to the OIS plate 341.

[0100] The table connection member 342 is fixed to the OIS clamp guide fixing portion 135 of the second table 13 (see Fig.10 The table connection member 342 has a structure for sandwiching the root of the extension portion 341a of the OIS plate 341 in the width direction, for example. This can prevent the OIS plate 341 from being displaced and falling off over time, thereby improving reliability.

[0101] The spacing width between the OIS motor abutment portions 341b is set to be wider than the spacing width between the free ends of the arm portions 312 of the OIS resonance portion 31. In the present embodiment, the table connection component 342 has an isolation portion 342a and a plate fixing portion 342b at the portion connecting the OIS plate 341. The plate fixing portion 342b is formed in a groove shape for the end of the OIS plate 341 to be inserted. The width of the isolation portion 342a is made larger than the width of the plate fixing portion 342b, whereby the two extension portions 341a are configured to separate from each other as they approach the OIS motor abutment portion 341b, and the width between the OIS motor abutment portions 341b is also expanded. When the OIS power transmission portion 34 is installed between the arm portions 312 of the OIS resonance portion 31, the extension portion 341a acts as a leaf spring, so that the pushing force acts in the direction of pushing the arm portions 312 away. The OIS power transmission portion 34 is held between the free ends of the arm portion 312 by this pressing force, so that the driving force from the OIS resonance portion 31 is efficiently transmitted to the OIS power transmission portion 34 .

[0102] The OIS resonance part 31 and the OIS power transmission part 34 only contact each other when being urged. Therefore, if the contact part is enlarged in the X direction or the Y direction, the movement stroke of the OIS movable part 10 can be lengthened without increasing the outer shape of the optical element driving device 1 .

[0103] The X-direction drive unit 30X is fixed to the OIS movable part 10 (first stage 12) and connected to the second stage 13 via the OIS power transmission unit 34. When the Y-direction drive unit 30Y performs the shake correction in the Y direction, the X-direction drive unit 30X moves together with the OIS movable part 10. On the other hand, the Y-direction drive unit 30Y is fixed to the OIS fixed part 20 (base 21) and connected to the second stage 13 via the OIS power transmission unit 34, and is not affected by the shake correction in the X direction performed by the X-direction drive unit 30X. That is, the movement of the OIS movable part 10 performed by one OIS drive unit 30 is not hindered by the structure of the other OIS drive unit 30. Therefore, the OIS movable part 10 can be prevented from rotating around the Z axis, so that the OIS movable part 10 can be moved with good accuracy in the XY plane.

[0104] A damping material (not shown) may be disposed between the two extensions 341a. The damping material is disposed, for example, after the OIS power transmission unit 34 is connected between the two arm portions 312 of the OIS resonance unit 31. The damping material is formed of a gel-like resin material having a viscosity and elasticity that allows it to be retained between the two extensions 341a without affecting the movement of the OIS power transmission unit 34. As the damping material, for example, a silicone material or a silicone-based damping material may be applied.

[0105] By disposing the damping material between the two extensions 341a, the vibration of the two extensions 341a is effectively damped in a short time, and the air vibration caused by the vibration transmission from the opposite second surface is also suppressed. Therefore, the generation of driving sound can be suppressed, and the quiet performance of the optical element driving device 1 will be significantly improved.

[0106] Preferably, the damping material is only disposed on the extension portion 341a of the OIS plate 341, and not on the OIS motor contact portion 341b. Thus, the influence of the damping material on the contact state (sliding state) between the OIS motor contact portion 341b and the OIS resonance portion 31 can be suppressed, and stable driving performance can be obtained as in the case where the damping material is not provided.

[0107] In addition, in the present embodiment, a structure for suppressing a decrease in driving performance due to wear is applied to the contact portion between the arm portion 312 of the OIS resonance portion 31 and the OIS plate 341 in the OIS driving unit 30. Figures 9A to 9C A contact portion between the OIS resonant portion 31 and the OIS plate 341 is shown. Fig.9A is a perspective view of the OIS driving unit 30, Fig. 9B is a side view of the OIS driving unit 30, Fig. 9C It is an enlarged view of the contact part.

[0108] like Figures 9A to 9C As shown, a sliding plate 343 formed of a ceramic material such as zirconia is disposed in the OIS motor contact portion 341b of the OIS plate 341. That is, in this embodiment, the sliding plate 343 becomes a passive side contact portion that contacts the front end (active side contact portion) of the arm portion 312 of the OIS resonance portion 31. The sliding plate 343 is fixed to the OIS motor contact portion 341b by bonding, for example.

[0109] The size of the sliding plate 343 in a plan view is set larger than the region in contact with the active-side contact portion when the OIS movable unit 10 moves in the X direction or the Y direction. In addition, the thickness of the sliding plate 343 is preferably smaller than that of the OIS plate 341 .

[0110] When the sliding plate 343 is formed of zirconia, the Vickers hardness of zirconia is 1200 to 1400 HV, which is higher than the hardness of the stainless steel forming the active side contact portion (180 to 400 HV). In addition, the surface roughness of the sliding plate 343 is smaller than the surface roughness of the active side contact portion and is smooth. Preferably, the surface roughness of the sliding plate 343 is, for example, 0.1 μm or less in terms of arithmetic mean roughness Ra.

[0111] As described above, by forming the active side contact portion from metal and the passive side contact portion from ceramic material, it is possible to suppress condensation that may cause wear. In addition, since it is mainly the OIS resonance portion 31 that is the active side contact portion that is ground, it is possible to easily improve the wear resistance by controlling the surface state of the active side contact portion. In addition, by preventing the sliding plate 343 that is the passive side contact portion from being worn, the stability of the movement can be improved. In other words, if stripe-shaped wear marks are formed on the contact surface due to local wear on the sliding plate 343, unexpected movement may occur when the active element detaches from the wear mark, but this problem can be prevented from occurring.

[0112] Furthermore, in the present embodiment, a dust collecting portion 35 (surrounding portion) is provided so as to surround the portion where the sliding plate 343 (passive side contact portion) contacts the front end (active side contact portion) of the arm portion 312 of the OIS resonance portion 31. Specifically, the dust collecting portion 35 has an elastic portion 351 and a flange portion 352. The dust collecting portion 35 closes the space including the contact region between the passive side contact portion and the active side contact portion, thereby preventing the abrasion powder generated in the contact region from scattering.

[0113] The elastic part 351 is formed of a viscous fluid such as grease and gel-like resin. The elastic part 351 is formed in a rectangular frame shape, for example, so as to surround the contact area between the passive side contact part and the active side contact part. The elastic part 351 has the property of being able to elastically deform while maintaining a predetermined shape to follow the movement of the OIS movable part 10. That is, the contact state between the passive side contact part and the active side contact part is not affected by the elastic part 351.

[0114] The flange portion 352 is configured to close the opening of the elastic portion 351. The flange portion 352 is formed by, for example, attaching a rectangular frame-shaped hard molded body to the arm portion 312 of the OIS resonator portion 31 and pressing it against the elastic portion 351, and pouring an adhesive such as epoxy resin between the arm portion 312 and the hard molded body and curing it. As a result, the opening of the elastic portion 351 is hermetically sealed.

[0115] Thus, by providing the dust collecting portion 35, even if wear powder is generated in the contact region, it is possible to prevent the wear powder from scattering to the outside of the dust collecting portion 35. Therefore, it is possible to suppress a decrease in driving performance due to scattering of the wear powder.

[0116] Figure 10 to Figure 12 It is an exploded perspective view of the OIS movable part 10 . Fig.11 Show that Fig.10 The state after rotating 180° around the Z axis. Fig.12 It means that Fig.10 The bottom three-dimensional image is a state after rotating 180 degrees around the Z axis. Fig.11 The AF driving unit 14 and the X-direction driving unit 30X are shown in a state where they are removed from the first stage portion 12 .

[0117] Hereinafter, in the rectangle which is the top view shape of the optical element driving device 1, the side where the AF driving unit 14 is configured is referred to as the "first side", the side where the X-direction driving unit 30X is configured is referred to as the "second side", the side where the Y-direction driving unit 30Y is configured is referred to as the "third side", and the remaining side is referred to as the "fourth side".

[0118] like Figure 10 to Figure 12 As shown, in this embodiment, the OIS movable part 10 includes an AF movable part 11, a first stage 12, a second stage 13, an AF driving unit 14, and an AF supporting part 15. With respect to the movement in the Y direction, the entire OIS movable part 10 including the first stage 12 and the second stage 13 serves as a movable body, whereas with respect to the movement in the X direction, the second stage 13 functions as an OIS fixed part 20, and only the AF unit (the AF movable part 11 and the first stage 12) functions as the OIS movable part 10. In addition, the first stage 12 functions as an AF fixed part that supports the AF movable part 11.

[0119] The AF movable section 11 is a member for holding the lens section 2 (see Figure 2 The AF movable part 11 is arranged radially inwardly spaced relative to the first stage 12 (AF fixed part) and supported by the first stage 12 with force applied thereto via the AF support part 15.

[0120] The AF movable part 11 is formed 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.

[0121] The AF movable part 11 has protrusions 112A to 112D protruding radially outward and extending in the optical axis direction on the outer peripheral surface of the lens housing 111. The protrusions 112A to 112D protrude further toward the imaging side in the optical axis direction than the lower surface of the lens housing 111, and abut against the second base portion 213 of the base 21, thereby restricting the movement of the AF movable part 11 toward the imaging side (lower side) in the optical axis direction. In the present embodiment, the protrusions 112A to 112D abut against the second base portion 213 of the base 21 in the reference state in which the AF drive unit 14 is not driven.

[0122] In addition, a magnet housing portion 114 is provided on the outer peripheral surface of the lens housing portion 111. The magnet housing portion 114 houses the magnet 16Z for Z position detection. The magnet 16Z is disposed in the magnet housing portion 114. In the sensor substrate 22, a magnetic sensor 25Z for Z position detection is disposed at a position opposite to the magnet 16Z in the optical axis direction (see Figure 5 ).

[0123] The first stage 12 supports the AF movable section 11 via the AF support section 15. The second stage 13 is arranged on the optical axis direction imaging side of the first stage 12 via the X-direction reference balls 42A to 42D. The first stage 12 moves in the X-direction and the Y-direction during the shake correction, and the second stage 13 moves only in the Y-direction during the shake correction.

[0124] The first stage 12 is a member that is substantially rectangular in a plan view from the optical axis direction, and is formed of, for example, a liquid crystal polymer. The first stage 12 has a substantially circular opening 121 in a portion corresponding to the AF movable portion 11. A cutout portion 122 corresponding to the protrusions 112A to 112D and the magnet receiving portion 114 of the AF movable portion 11 is formed in the opening 121. In the first stage 12, a portion corresponding to the X-direction drive unit 30X (the outer side surface of the side wall along the second side) is formed to be recessed radially inward (OIS motor fixing portion 124) so ​​that the X-direction drive unit 30X can be arranged without protruding radially outward. In addition, in the first stage 12, a portion corresponding to the Y-direction drive unit 30Y (the outer side surface of the side wall along the third side) is also formed to be recessed radially inward.

[0125] The first stage 12 has X-direction reference ball retaining portions 123A to 123D on its lower surface for retaining X-direction reference balls 42A to 42D. The X-direction reference ball retaining portions 123A to 123D are formed as rectangular depressions extending in the X direction. The X-direction reference ball retaining portions 123A to 123D are opposite to the X-direction reference ball retaining portions 133A to 133D of the second stage 13 in the Z direction. The X-direction reference ball retaining portions 123A and 123B are formed in a substantially V-shaped (tapered) cross-sectional shape in such a manner that the groove width narrows toward the bottom surface side; the X-direction reference ball retaining portions 123C and 123D are formed in a substantially U-shaped shape.

[0126] In the first stage 12, an AF motor fixing portion 125 is formed on one side wall (side wall along the first side) along the X direction, and an AF resonance portion 141 as an active element of the AF drive unit 14 is arranged on the AF motor fixing portion 125. The AF motor fixing portion 125 has an upper fixing plate (not marked with a reference numeral) and a lower fixing plate 125a, and the AF resonance portion 141 is sandwiched between them. The AF resonance portion 141 is inserted into an insertion hole (not marked with a reference numeral) provided in the upper fixing plate and the lower fixing plate 125a, for example, and is fixed by bonding. The upper fixing plate is composed of a part of the wiring 17B, and the AF resonance portion 141 is electrically connected to the wiring 17B.

[0127] In the first stage 12, magnets 16X and 16Y for detecting XY positions are arranged on one side wall (the side wall along the fourth side) along the Y direction. For example, the magnet 16X is magnetized in the X direction, and the magnet 16Y is magnetized in the Y direction. In the sensor substrate 22, magnetic sensors 25X and 25Y for detecting XY positions are arranged at positions opposite to the magnets 16X and 16Y in the optical axis direction (see FIG. Figure 5 ).

[0128] In addition, wirings 17A and 17B are embedded in the first stage 12, for example, by insert molding. The wirings 17A and 17B are arranged, for example, along the first side and the second side. The wirings 17A and 17B are exposed from the four corners of the first stage 12, and one end of the OIS urging member 50 is connected to the portion. Power is supplied to the X-direction drive unit 30X via the wiring 17A, and power is supplied to the AF drive unit 14 via the wiring 17B.

[0129] The second stage 13 is a member that is substantially rectangular in plan view from the optical axis direction, and is formed of, for example, a liquid crystal polymer. An inner peripheral surface 131 of the second stage 13 is formed corresponding to the outer shape of the AF movable part 11. In the second stage 13, portions corresponding to the X-direction drive unit 30X and the Y-direction drive unit 30Y (outer surfaces of the side walls along the second side and the third side) are formed to be recessed radially inward, similarly to the first stage 12.

[0130] The second stage 13 has Y-direction reference ball retaining portions 134A to 134C on its lower surface for accommodating the Y-direction reference balls 41A to 41C. The Y-direction reference ball retaining portions 134A to 134C are formed as rectangular depressions extending in the Y direction. The Y-direction reference ball retaining portions 134A to 134C are opposite to the Y-direction reference ball retaining portions 217A to 217C of the base 21 in the Z direction. The Y-direction reference ball retaining portions 134A and 134B are formed in a substantially V-shaped (conical) cross-sectional shape in such a manner that the groove width narrows toward the bottom surface side; the Y-direction reference ball retaining portion 134C is formed in a substantially U-shaped shape.

[0131] In addition, the second stage 13 has X-direction reference ball retaining portions 133A to 133D on its upper surface for accommodating the X-direction reference balls 42A to 42D. The X-direction reference ball retaining portions 133A to 133D are formed as rectangular depressions extending in the X direction. The X-direction reference ball retaining portions 133A to 133D are opposite to the X-direction reference ball retaining portions 123A to 123D of the first stage 12 in the Z direction. The X-direction reference ball retaining portions 133A to 133D are formed in a substantially V-shaped (tapered) cross-sectional shape so that the groove width narrows toward the bottom surface side. In this embodiment, the X-direction reference ball retaining portions 133A and 133B are arranged on the side (second side) of the second stage 13 where the X-direction drive unit 30X is configured, and the X-direction reference ball retaining portions 133C and 133D are arranged on the side (first side) where the AF drive unit 14 is configured, so that the first stage 12 is supported at four points by the X-direction reference balls 42A to 42D.

[0132] The Y-direction reference balls 41A to 41C constituting the OIS support portion 40 are held by the Y-direction reference ball holders 217A to 217C of the base 21 and the Y-direction reference ball holders 134A to 134C of the second stage 13 in a multi-point contact manner. Therefore, the Y-direction reference balls 41A to 41C stably roll in the Y-direction.

[0133] The X-direction reference balls 42A to 42D are held in multi-point contact by the X-direction reference ball holders 133A to 133D of the second stage 13 and the X-direction reference ball holders 123A to 123D of the first stage 12. Therefore, the X-direction reference balls 42A to 42D roll stably in the X-direction.

[0134] The AF support portion 15 is a portion that supports the AF movable portion 11 relative to the first stage portion 12 (AF fixed portion). The AF support portion 15 is composed of a first Z-direction reference ball 15A and a second Z-direction reference ball 15B. The first Z-direction reference ball 15A and the second Z-direction reference ball 15B are interposed between the AF movable portion 11 and the first stage portion 12 in a rollable state. In the present embodiment, the first Z-direction reference ball 15A and the second Z-direction reference ball 15B are each composed of a plurality of balls (here, two) arranged in the Z direction.

[0135] The AF drive unit 14 is an actuator that moves the AF movable part 11 in the Z direction. The AF drive unit 14 is composed of an ultrasonic motor, similar to the OIS drive unit 30. The AF drive unit 14 is fixed to the AF motor fixing part 125 of the first stage 12 in such a manner that the arm part 141b extends in the Z direction. The AF drive unit 14 has an AF ultrasonic motor USM2 and an AF power transmission part 144.

[0136] The structure of the AF drive unit 14 (excluding the AF power transmission unit 144) is as follows: Fig.13A , Fig. 13B shown. Fig.13A 1 shows the state in which the components of the AF drive unit 14 are assembled. Fig. 13B 1 and 2 show a disassembled state of the components of the AF drive unit 14. The structure of the AF drive unit 14 is almost the same as that of the OIS drive unit 30. It should be noted that the overall structure of the AF drive unit 14 including the AF power transmission unit 144 will be described later.

[0137] The AF ultrasonic motor USM2 is composed of an AF resonance portion 141, an AF piezoelectric element 142, and an AF electrode 143. The driving force of the AF ultrasonic motor USM2 is transmitted to the AF movable portion 11 via the AF power transmission portion 144. That is, in the AF driving unit 14, the AF resonance portion 141 constitutes an active element, and the AF power transmission portion 144 constitutes a passive element.

[0138] The AF piezoelectric element 142 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 142 are arranged so as to sandwich the body portion 141 a of the AF resonance portion 141 .

[0139] The AF electrode 143 sandwiches the AF resonance portion 141 and the AF piezoelectric element 142 , and applies a voltage to the AF piezoelectric element 142 .

[0140] The AF resonance part 141 is formed of a conductive material, resonates with the vibration of the AF piezoelectric element 142, and converts the vibration motion into a linear motion. The AF resonance part 141 includes a substantially rectangular body part 141a sandwiched by the AF piezoelectric element 142, two arm parts 141b extending from the body part 141a in the Z direction, a power supply part 141d extending from the center of the body part 141a in the Z direction and electrically connected to the power supply path (wiring 17B (upper fixing plate) of the first table part 12), and a table part fixing part 141c extending from the center of the body part 141a to the side opposite to the power supply part 141d.

[0141] The two arm portions 141b have symmetrical shapes, and their respective free ends abut against the AF power transmission portion 144, and deform symmetrically in resonance with the vibration of the AF piezoelectric element 142. In the two arm portions 141b of the present embodiment, the surface abutting against the AF plate 61 of the AF power transmission portion 144 is formed to face outward, and the free ends are configured to be clamped by the AF plate 61.

[0142] The AF resonance part 141 may be made of any metal having predetermined conductivity, shear strength, hardness, specific gravity, Young's modulus, etc. For example, stainless steel is suitable as in the case of the OIS resonance part 31. The AF resonance part 141 is formed by laser processing, etching, or press processing of a metal plate, for example.

[0143] The AF piezoelectric element 142 is attached to the body portion 141a of the AF resonance portion 141 in the thickness direction and is sandwiched by the AF electrode 143 so that they are electrically connected to each other. By connecting the current-carrying portion 141d of the AF resonance portion 141 and the AF electrode 143 to the wiring 17B of the first stage portion 12, a voltage is applied to the AF piezoelectric element 142, thereby generating vibration.

[0144] The AF resonance portion 141 has at least two resonance frequencies, similarly to the OIS resonance portion 31, and deforms in different motions for each resonance frequency. In other words, the overall shape of the AF resonance portion 141 is set so as to deform in different motions for the two resonance frequencies.

[0145] Fig.14A , Fig. 14B 1 is a diagram showing a holding structure of the AF drive unit 14. Fig. 14B , the holding structure of the AF drive unit 14 is exploded and shown. Fig.15 This is a top view of the OIS movable part 10 as viewed from the light receiving side in the optical axis direction. Fig.15 In FIG. 1 , the second stage 13 is not shown. Fig.16A , Fig. 16B It is a plan view of the AF movable section 11 and the first stage section 12 . Fig.17A , Fig. 17B 1 and 2 are cross-sectional views and longitudinal cross-sectional views of the peripheral portion of the AF drive unit 14 . Fig.17A yes Fig. 17B The CC section view, Fig. 17B yes Fig.15 BB section view. Fig.18A , Fig.18B It is an enlarged view showing the arrangement of the AF support section 15 .

[0146] like Fig.14A , Fig. 14B As shown in FIG. 1 and FIG. 2 , the protrusions 112A and 112B of the AF movable section 11 are arranged to face each other in the X direction, and form a space extending in the tangential direction (here, the X direction) of the lens housing section 111 .

[0147] The protrusions 112A and 112B hold the Z-direction reference balls 15A and 15B as the AF support portion 15 together with the first stage portion 12. A first Z-direction reference ball holding portion 113a for accommodating the first Z-direction reference ball 15A is formed on one protrusion 112A. A second Z-direction reference ball holding portion 113b for accommodating the second Z-direction reference ball 15B is formed on the other protrusion 112B. The first Z-direction reference ball holding portion 113a and the second Z-direction reference ball holding portion 113b are formed so that the cross-sectional shape is substantially V-shaped (tapered) in such a manner that the groove width becomes narrower toward the bottom surface side.

[0148] In the AF movable part 11, the space formed by the protrusions 112A and 112B is used as a drive unit housing portion 115 for arranging the AF drive unit 14. The protrusions 112A and 112B have a plate housing portion 115c on the surface opposite to the first Z-direction reference ball holding portion 113a and the second Z-direction reference ball holding portion 113b. The urging member 62 and the AF power transmission portion 144 as a passive element of the AF drive unit 14 are arranged in the plate housing portion 115c.

[0149] The AF power transmission part 144 is a clamping guide having a predetermined length in the Z direction. In the present embodiment, the AF power transmission part 144 is composed of two AF plates 61. Specifically, the AF plate 61 is interposed between the AF resonance part 141 and the force applying member 62 of the AF drive unit 14. The power of the AF resonance part 141 is transmitted to the AF movable part 11 via the AF plate 61.

[0150] The AF plate 61 is a hard plate-shaped member made of a metal material such as titanium copper, nickel copper, or stainless steel. The AF plate 61 is arranged in the moving direction of the AF movable part 11 in such a manner that its first surface abuts against the arm portion 141b of the AF resonance portion 141, and is movable integrally with the AF movable part 11. The AF plate 61 is arranged in the plate receiving portion 115c of the AF movable part 11 and is physically locked. Specifically, the AF plate 61 is fixed to the AF movable part 11 by loosely fitting the guide insertion portion 611 of the AF plate 61 into the guide groove 115a provided in the AF movable part 11, and by arranging the fixing piece 612 between the bottom surface of the plate receiving portion 115c and the locking piece 115b.

[0151] The AF plate 61 may be fixed to the AF movable portion 11 so as to follow the mounting state (individual difference in mounting position) of the AF resonance portion 141 , and may be bonded without bonding or with an elastically deformable soft adhesive (eg, silicone rubber).

[0152] A damping material (not shown) may also be disposed between the second surface (the surface opposite to the first surface) and the opposite surface of the AF plate 61. Specifically, the damping material is filled in a manner that fills the plate receiving portion 115c in which the AF plate 61 is disposed. The damping material is formed, for example, in a state where the AF drive unit 14 is assembled. The damping material is formed of a gel-like resin material having viscosity and elasticity to such an extent that it can be retained in the plate receiving portion 115c and does not affect the pushing force of the force applying member 62. As the damping material, for example, a silicone material or a silicone-based damping material may be applied.

[0153] By disposing the damping material in the plate receiving portion 115c where the AF plate 61 is disposed, the vibration of the AF plate 61 is effectively damped in a short time, and the air vibration caused by the vibration transmission from the second surface is also suppressed. Therefore, the generation of the driving sound can be suppressed, and the quiet performance of the optical element driving device 1 is significantly improved.

[0154] The urging member 62 is a member for urging the AF plate 61 toward the arm 141b of the AF resonance portion 141, and has two spring portions 621. The spring portions 621 are configured to press the AF plate 61 toward the arm 141b with the same urging force. The urging force of the spring portions 621 is not affected by the damping material.

[0155] The urging member 62 is formed by sheet metal processing, for example, and the spring portion 621 is composed of a leaf spring extending from the connecting portion 622. Specifically, the leaf spring of the spring portion 621 extends from the lower portion of the connecting portion 622 to the Z direction - side, is bent outwardly into a hairpin shape, and is formed to be inclined inwardly relative to the Z direction.

[0156] The force-applying member 62 is fixed to the AF movable part 11 by placing the connecting portion 622 of the force-applying member 62 on the spring-applying portion 115d provided in the drive unit housing portion 115 and arranging the spring portion 621 in the plate housing portion 115c. As a result, the AF plate 61 is located at the hairpin portion of the force-applying member 62 and is urged inward (to the arm portion 141b side) by the spring portion 621. The force-applying member 62 is not bonded to the AF movable part 11 so that it can follow the installation position of the AF drive unit 14. That is, the force-applying member 62 can move along the installation surface of the drive unit housing portion 115 and be held in a position where the force loads of the two spring portions 621 are equal when the AF drive unit 14 (AF resonance portion 141 and AF plate 61) are clamped. It should be noted that the structure of the force-applying member 62 is an example and can be appropriately changed. For example, elastic bodies such as coil springs and hard rubber can also be applied.

[0157] In the first stage 12, the portions corresponding to the protrusions 112A and 112B of the AF movable part 11 and the space therebetween are cut away to form an AF motor fixing part 125. In addition, on both sides of the AF motor fixing part 125, a first Z-direction reference ball holding part 127a and a second Z-direction reference ball holding part 127b are continuously provided.

[0158] The first Z-direction reference ball holding portion 127a is formed along the tangential direction D1 of the lens receiving portion 111 (see Fig.18A ). In addition, the inner surface of the first Z-direction reference ball holding portion 127a (the surface on the AF motor fixing portion 125 side) is formed in a substantially V-shaped (tapered) cross-sectional shape so that the groove width becomes narrower toward the bottom side.

[0159] The second Z-direction reference ball holding portion 127 b is formed to be inclined with respect to the tangential direction D1 of the lens housing portion 111 (see Fig.18B ). In addition, the inner surface of the second Z-direction reference ball holding portion 127b (the surface on the AF motor fixing portion 125 side) is formed so that its cross-sectional shape is roughly U-shaped. The second Z-direction reference ball holding portion 127b is provided with a second Z-direction reference ball 15B and a force applying portion 18 (a leaf spring 181 and a spacer 182) for applying force to the AF movable portion 11 via the second Z-direction reference ball 15B. It should be noted that Fig. 16B , a state in which the leaf spring 181 is removed is shown.

[0160] The second Z-direction reference ball 15B is biased in a direction inclined with respect to the tangential direction D1 of the lens receiving portion 111 (see Fig.18B ). Thus, the AF movable part 11 is pressed in two orthogonal directions, namely, the X direction and the Y direction, through the second Z-direction reference ball 15B, and is held in a stable posture in the plane orthogonal to the optical axis. When the angle between the tangent direction D1 and the force direction D2 is set to θ, and the preload of the leaf spring 181 is set to F, the pressing force in the Y direction is F1 = F·sinθ, and the pressing force in the X direction is F2 = F·cosθ.

[0161] Here, the angle θ formed by the tangent direction D1 and the force direction D2 is, for example, 0° to 45° (excluding 0°). For example, the force direction D2 is set in a manner that limits the rotation of the AF movable part 11 around the optical axis in consideration of the balance with the preload F. For example, if the angle θ formed by the force direction D2 and the tangent direction D1 is increased, the pressing force in the Y direction becomes larger, so the preload F of the leaf spring 181 can be reduced, but it is disadvantageous in terms of space, for example, it is necessary to increase the protruding length of the protrusions 112A and 112B. On the contrary, if the angle θ formed by the force direction D2 and the tangent direction D1 is reduced, it is more advantageous in terms of space, but the pressing force in the Y direction becomes smaller, so it is necessary to increase the preload of the leaf spring 181.

[0162] The first Z-direction reference ball 15A is held in a rollable state between the first Z-direction reference ball holding portions 113a and 127a of the AF movable portion 11 and the first stage portion 12. In addition, the second Z-direction reference ball 15B is held in a rollable state between the spacer 182 arranged on the second Z-direction reference ball holding portion 127b of the first stage portion 12 and the second Z-direction reference ball holding portion 113b of the AF movable portion 11. The AF movable portion 11 is supported by the first stage portion 12 via the first Z-direction reference ball 15A and the second Z-direction reference ball 15B in a state where a force is applied, and is held in a stable posture.

[0163] The first Z-direction reference ball 15A is held between the AF movable section 11 and the first stage 12, so that its movement in the direction perpendicular to the optical axis (rotation of the AF movable section 11) is restricted. Thus, the AF movable section 11 can be moved in the optical axis direction in a stable manner.

[0164] On the other hand, the second Z-direction reference ball 15B is sandwiched between the AF movable part 11 and the first stage 12 via the leaf spring 181 and the spacer 182, and can move in the direction perpendicular to the optical axis. This can absorb the dimensional tolerance of the AF movable part 11 and the first stage 12, and improve the stability of the AF movable part 11 when moving.

[0165] In addition, the portion where the AF drive unit 14 is disposed is configured as follows: a structure in which the first Z-direction reference ball 15A and the second Z-direction reference ball 15B are sandwiched, and a preload is applied to the second Z-direction reference ball 15B, that is, a structure in which the AF movable part 11 is supported at one point on the first stage 12. As a result, the distance from the force point that receives the driving force of the AF drive unit 14 to the rotation axis can be easily reduced, and the moment and preload can be reduced. In addition, by making the second Z-direction reference ball 15B function as a preload ball, the rolling resistance can be reduced. Therefore, the driving efficiency of the AF drive unit 14 is improved, and it is also suitable for use as a lens driving device for large-diameter lenses. In addition, if the preload is the same, the anti-tilt property is improved.

[0166] In addition, the first Z-direction reference ball 15A and the second Z-direction reference ball 15B are each composed of two balls. In this case, the rolling resistance of the first Z-direction reference ball 15A and the second Z-direction reference ball 15B is smaller than when the first Z-direction reference ball 15A and the second Z-direction reference ball 15B are composed of three or more balls.

[0167] In the optical element driving device 1, when a voltage is applied to the AF driving unit 14, the AF piezoelectric element 142 vibrates, and the AF resonance part 141 deforms in accordance with the frequency. The driving force of the AF driving unit 14 causes the AF power transmission part 144 to slide in the Z direction. Along with this, the AF movable part 11 moves in the Z direction to perform focusing. Since the AF support part 15 is composed of balls, the AF movable part 11 can move smoothly in the Z direction. In addition, the AF driving unit 14 and the AF power transmission part 144 only abut against each other in a state where a force is applied. Therefore, as long as the abutting part is enlarged in the Z direction, the moving stroke of the AF movable part 11 can be easily lengthened without hindering the low height of the optical element driving device 1.

[0168] In the optical element driving device 1, when a voltage is applied to the OIS driving unit 30, the OIS piezoelectric element 32 vibrates, and the OIS resonance part 31 deforms in accordance with the frequency. The driving force of the OIS driving unit 30 causes the OIS power transmission part 34 to slide in the X direction or the Y direction. As a result, the OIS movable part 10 moves in the X direction or the Y direction, thereby performing shake correction. Since the OIS support part 40 is composed of a ball, the OIS movable part 10 can move smoothly in the X direction or the Y direction.

[0169] Specifically, when the X-direction driving unit 30X is driven and the OIS power transmission unit 34 moves in the X-direction, power is transmitted from the first stage 12 equipped with the X-direction driving unit 30X to the second stage 13. At this time, the ball 41 clamped by the second stage 13 and the base 21 cannot roll in the X-direction, so the position of the second stage 13 in the X-direction relative to the base 21 remains unchanged. On the other hand, the ball 42 clamped by the first stage 12 and the second stage 13 can roll in the X-direction, so the first stage 12 moves in the X-direction relative to the second stage 13. That is, the second stage 13 constitutes the OIS fixed part 20, and the first stage 12 constitutes the OIS movable part 10.

[0170] In addition, when the Y-direction driving unit 30Y is driven and the OIS power transmission part 34 moves in the Y-direction, power is transmitted from the base 21 equipped with the Y-direction driving unit 30Y to the second stage 13. At this time, the ball 42 clamped by the first stage 12 and the second stage 13 cannot roll in the Y-direction, so the position of the first stage 12 relative to the second stage 13 in the Y-direction remains unchanged. On the other hand, the ball 41 clamped by the second stage 13 and the base 21 can roll in the Y-direction, so the second stage 13 moves in the Y-direction relative to the base 21. The first stage 12 also moves in the Y-direction following the second stage 13. That is, the base 21 constitutes the OIS fixed part 20, and the AF unit including the first stage 12 and the second stage 13 constitutes the OIS movable part 10.

[0171] In this way, the OIS movable part 10 moves in the XY plane, thereby performing shake correction. Specifically, the energization voltage of the OIS drive units 30X and 30Y is controlled based on the detection signal indicating the angular shake from the shake detection unit (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 unit composed of the magnets 16X and 16Y and the magnetic sensors 25X and 25Y, the translation movement of the OIS movable part 10 can be accurately controlled.

[0172] As described above, the optical element driving device 1 of the present embodiment includes: an OIS fixed portion 20 (fixed portion); an OIS movable portion 10 (movable portion) arranged to be spaced apart from the OIS fixed portion 20; an OIS support portion 40 (support portion) supporting the OIS movable portion 10 on the OIS fixed portion 20; an OIS driving unit 30 (driving unit) including an ultrasonic motor USM1 having a piezoelectric element 32 and an OIS resonance portion 31 (active element) that resonates with the vibration of the piezoelectric element 32, and an OIS plate 341 (passive element) that contacts the OIS resonance portion 31 and moves relative to the OIS resonance portion 31 when a force is applied, and the OIS driving unit 30 moves the OIS movable portion 10 relative to the OIS fixed portion 20, and the sliding plate 343 as the passive side contact portion of the OIS plate 341 is formed of a ceramic material having a higher hardness than the front end (active side contact portion) of the arm portion 312 of the OIS resonance portion 31.

[0173] This can suppress the aggregation that causes wear, and can suppress the wear of the sliding plate 343 as the passive side contact portion. Therefore, it is possible to suppress the decrease in driving performance over time due to wear of the active element or the passive element, and the reliability of the optical element driving device 1 can be improved.

[0174] In addition, in the optical element driving device 1, the surface roughness of the sliding plate 343 (passive side contact portion) is smaller than the surface roughness of the front end (active side contact portion) of the arm portion 312 of the OIS resonator 31. Thus, the wear of the arm portion 312 of the OIS resonator 31 as the active side contact portion can be more effectively suppressed.

[0175] In addition, in the optical element driving device 1, the OIS plate 341 (passive element) has a biasing function of biasing the sliding plate 343 (passive side contact portion) toward the front end (active side contact portion) of the arm portion 312 of the OIS resonance portion 31, and the sliding plate 343 is formed of a member different from the OIS plate 341. Thus, a passive element having a passive side contact portion with high hardness can be easily manufactured.

[0176] In addition, in the optical element driving device 1, the sliding plate 343 (passive side contact portion) and the OIS plate 341 (passive element) are plate-shaped, and the thickness of the sliding plate 343 is smaller than the thickness of the OIS plate 341. As a result, the movement of the sliding plate 343 and the OIS plate 341 are linked, and the function of the OIS plate 341 as a leaf spring can be prevented from being hindered.

[0177] The optical element driving device 1 includes a dust collecting portion 35 (surrounding portion) surrounding at least a portion of a contact region between the slide plate 343 (passive side contact portion) and the tip of the arm portion 312 of the OIS resonator 31 (active side contact portion).

[0178] Specifically, in the optical element driving device 1 , the dust collecting portion 35 includes the elastic portion 351 which is formed of a viscous fluid and elastically deforms along with the movement of the OIS movable portion 10 .

[0179] The elastic portion 351 is formed in a frame shape so as to surround the contact region, and the dust collecting portion 35 has a flange portion 352 that is fixed to the arm portion 312 (active element) of the OIS resonator portion 31 and closes the opening of the elastic portion 351 .

[0180] Thus, even if wear powder is generated in the contact region, it is possible to prevent the wear powder from scattering to the outside of the dust collecting portion 35. Therefore, it is possible to suppress a reduction in driving performance due to scattering of the wear powder.

[0181] 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.

[0182] 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 notebook 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.

[0183] Fig.19A , Fig.19B 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.19A This is the front view of the car V. Fig.19B 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.19A , Fig.19B As shown, the vehicle-mounted camera module VC is mounted on the windshield facing forward, or mounted on the tailgate facing backward. The vehicle-mounted camera module VC is used as a vehicle-mounted camera module for rear monitoring, driving recorder, collision avoidance control, automatic driving control, etc.

[0184] In the embodiment, the passive side contact portion is formed by bonding the slide plate 343 to the OIS plate 341 as a passive element, but the passive side contact portion made of ceramic may be formed on the motor contact portion 341 b of the OIS plate 341 by coating.

[0185] In addition, in the embodiment, a case where a structure for suppressing a reduction in driving performance due to wear is applied to a contact portion where the arm portion 312 of the OIS resonance portion 31 in the OIS drive unit 30 contacts the OIS plate 341 is described, but the same structure may be applied to a contact portion where the arm portion 141b (active side contact portion) of the AF resonance portion 141 in the AF drive unit 14 contacts the AF plate 61 (passive side contact portion).

[0186] In addition, in an embodiment, the first invention of providing a passive side contact portion formed of a ceramic material having a higher hardness than the active side contact portion and the second invention of providing a dust collecting portion in the contact area between the active side contact portion and the passive side contact portion are applied in combination to suppress the reduction in driving performance due to wear, but each invention may also be applied independently.

[0187] The dust collecting portion 35 is not limited to the structure disclosed in the embodiment, and may be any structure as long as it surrounds at least a portion of the contact region between the active side contact portion and the passive side contact portion and can suppress scattering of wear powder generated in the contact region.

[0188] 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.

[0189] 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.

[0190] The disclosure of the specification, drawings, and abstract included in U.S. Provisional Application No. 63 / 117,857 filed on November 24, 2020 is incorporated herein by reference in its entirety.

[0191] Description of Reference Numerals

[0192] 1Optical element drive device

[0193] 10OIS movable part (movable part)

[0194] 12 First Station

[0195] 13 Second Station

[0196] 14 AF drive unit

[0197] 141AF resonance part (active element)

[0198] 142 AF Piezoelectric Element

[0199] 143 AF Electrode

[0200] 144 AF power transmission unit

[0201] 15 AF support

[0202] 20OIS fixed part (fixed part)

[0203] 21 Base

[0204] 30 OIS driver unit

[0205] 31OIS resonance part (active element)

[0206] 32 OIS piezoelectric element

[0207] 33 OIS electrode

[0208] 34 OIS power transmission unit

[0209] 35 dust collecting part (surrounding part)

[0210] 341OIS board (passive element)

[0211] 40OIS support part

[0212] 312 arm (active side contact part)

[0213] 343 Sliding plate (passive side contact part)

[0214] 351 Elasticity

[0215] 352 flange

[0216] A Camera Module

[0217] M smartphone (camera-equipped device)

Claims

1. An optical element driving device, comprising: Fixed part; A movable part, arranged to be spaced apart from the fixed part; a supporting portion, supporting the movable portion on the fixed portion; and The driving unit includes an ultrasonic motor having a piezoelectric element and an active element that resonates with the vibration of the piezoelectric element, and a passive element that contacts the active element and moves relative to the active element when a force is applied, and the driving unit moves the movable part relative to the fixed part. The passive side contact portion of the passive element is formed of a ceramic material having a higher hardness than the active side contact portion of the active element.

2. The optical element driving device according to claim 1, wherein: The surface roughness of the passive-side contact portion is smaller than the surface roughness of the active-side contact portion.

3. The optical element driving device according to claim 1 or 2, wherein: The passive element has a function of applying force to the passive side contact part toward the active side contact part. The passive-side contact portion is formed of a component different from the passive element.

4. The optical element driving device according to claim 3, wherein: The passive side contact portion and the passive element are in plate shape, The passive-side contact portion has a thickness smaller than that of the passive element.

5. The optical element driving device according to claim 3, wherein: The passive element has a connecting part fixed to the movable part, The connecting member is formed of a member different from the passive-side contact portion.

6. A camera module comprising: The optical element driving device according to any one of claims 1 to 5; an optical element mounted on the movable portion; and The imaging unit captures the image of the object formed by the optical element.

7. A camera-mounted device, which is information equipment or transportation equipment, comprising: The camera module of claim 6; and The image processing unit processes the image information obtained by the camera module.

Images