Drive device, camera module, and camera mounting device

Abstract

In a drive device, a camera module, and a camera mounting device according to the present invention, the drive device comprises: an AF unit including a first fixed part, a first movable part disposed at a distance from the first fixed part, a Z-direction drive part, and a first support part supporting the first movable part with respect to the first fixed part, a Z-direction driving unit that is an actuator that moves the first movable unit in the Z direction and that is composed of an ultrasonic motor that has a piezoelectric element and a resonance unit and converts vibration motion into linear motion; and an AF biasing member that functions as a leaf spring by coming into contact with the Z-direction drive unit in a state in which pressure is applied thereto, the AF biasing member biasing the first movable unit in one direction in a plane orthogonal to the Z direction with respect to the first fixed unit across the first support unit.

Description

[0001] This application is a divisional application of the Chinese invention patent application with the application date of November 10, 2020, application number 202080084165.5, invention name “Action method and controller of drive unit”, and applicants being Miniswise Co., Ltd. and Mitsumi Electric Co., Ltd. Technical Field

[0002] The present invention relates to the field of small drive devices such as piezoelectric drive devices. More specifically, the present invention relates to an operating method and a controller for a drive unit as described in the preamble of the corresponding independent claim. Background Art

[0003] For example, small drive devices such as piezoelectric drive devices are disclosed in Patent Documents 1, 2, and 3. Such a drive device has one, two, or more arms that can vibrate, and drives the passive element by the vibration movement at the end of the arm. The frequency of the excitation unit that drives the vibration movement is selected in a manner to generate the following vibration mode, which is a vibration mode in which the arm moves the passive element in a first direction or an opposite second direction. In order to take into account the inherent nonlinear characteristics in the design of the drive device, especially in order to control the position of the passive element relative to the active element, further improvement of the drive device is required.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: International Publication No. 2006 / 000118

[0007] Patent Document 2: U.S. Patent No. 7,429,812

[0008] Patent Document 3: International Publication No. 2019 / 068708 Summary of the invention

[0009] Problem that the invention aims to solve

[0010] An object of the present invention is to provide a method for operating a drive unit capable of performing position control of the above-mentioned type of drive unit and a controller for controlling the operation of the drive unit.

[0011] Solutions to the problem

[0012] The above object is achieved by the operation method and controller of the drive unit described in the claims.

[0013] A driving device according to one embodiment of the present invention comprises: an AF unit, which includes a first fixed portion, a first movable portion arranged to be spaced apart from the first fixed portion, a Z-direction driving portion, and a first supporting portion supporting the first movable portion relative to the first fixed portion, the Z-direction driving portion being composed of an ultrasonic motor having a piezoelectric element and a resonance portion and converting vibration motion into linear motion, and being an actuator for moving the first movable portion in the Z direction; and an AF force applying component, which functions as a leaf spring by abutting against the Z-direction driving portion under pressure, the AF force applying component applying force to the first movable portion in one direction within a plane orthogonal to the Z direction relative to the first fixed portion across the first supporting portion.

[0014] A camera module according to one aspect of the present invention includes: the above-mentioned drive device; a lens unit included in the first movable unit; and an imaging unit that captures an object image formed by the lens unit.

[0015] A camera-mounted device according to one embodiment of the present invention is information equipment or transportation equipment, and includes: the camera module described above; and an image processing unit that processes image information obtained by the camera module.

[0016] The method for operating a driving unit of the present invention is a method for operating the driving unit, wherein the driving unit drives a passive element relative to an active element. In the method,

[0017] The active element comprises: a resonator and at least one excitation unit for exciting the vibration of the resonator.

[0018] The resonator includes at least one arm extending from a connecting portion of the resonator.

[0019] The at least one arm has a contact portion at an outer end of the arm,

[0020] The contact portion is movable by a vibrating movement of the at least one arm,

[0021] The passive element is configured to be driven by the vibration motion and move relative to the active element,

[0022] The passive element has a first contact area, and the first contact area is configured to contact the first contact portion.

[0023] The active element and the passive element are configured such that, when the active element is not excited, at least the first contact portion is pressed toward the first contact area due to the prestress,

[0024] The operation method of the driving unit includes the following steps:

[0025] The step of driving the excitation unit by a driving signal and repeatedly omitting the driving pulse to generate a periodically repeated pulse block, wherein the driving signal is a periodic signal including the driving pulse repeated at an excitation frequency, and the relationship between the on time Ton of the pulse block and the pulse block period Tb, Ton / Tb, is taken as the pulse block duty cycle; and

[0026] a step of correcting the drive signal corresponding to the position error signal,

[0027] In the step of correcting the driving signal,

[0028] When the position error signal is within the first range, the shape of the drive pulse is corrected so that the shape of the drive pulse becomes a first drive pulse shape or the excitation frequency is corrected according to a first excitation frequency offset value, and the pulse block duty cycle is set to a first pulse block duty cycle value,

[0029] When the position error signal is within the second range, the shape of the drive pulse is corrected so that it becomes a second drive pulse shape or the excitation frequency is corrected according to a second excitation frequency offset value, and the pulse block duty cycle is set to a second pulse block duty cycle value.

[0030] The controller of the present invention is a controller configured to execute the above-mentioned operation method of the driving unit.

[0031] The controller is connected to the excitation unit of the driving unit and supplies power to the excitation unit, reads a signal from a sensor and determines a position of the driving unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1A , Figure 1B This is a diagram showing a smartphone equipped with a camera module according to an embodiment of the present invention.

[0033] Figure 2 This is a stereoscopic view of the camera module.

[0034] Figure 3A , Figure 3B It is a perspective view of the appearance of the lens driving device according to the first embodiment.

[0035] Figure 4 It is an exploded perspective view of the lens driving device according to the first embodiment.

[0036] Figure 5 It is an exploded perspective view of the lens driving device according to the first embodiment.

[0037] Fig. 6A , Figure 6B It is a three-dimensional diagram of the OIS driving unit.

[0038] Figure 7 It is an exploded perspective view of the OIS movable portion according to the first embodiment.

[0039] Figure 8 It is an exploded perspective view of the OIS movable portion according to the first embodiment.

[0040] Fig. 9 It is an exploded perspective view of the OIS movable portion according to the first embodiment.

[0041] Fig. 10A , Fig. 10B It is a perspective view of the AF driving section according to the first embodiment.

[0042] Fig.11A , Fig. 11B It is a diagram showing a state in which the first stage unit, the AF driving unit, and the AF supporting unit according to the first embodiment are assembled.

[0043] Fig. 12A , Fig. 12B It is a perspective view of the appearance of a lens driving device according to a second embodiment.

[0044] Fig.13 It is an exploded perspective view of an OIS movable portion according to the second embodiment.

[0045] Fig.14 It is an exploded perspective view of an OIS movable portion according to the second embodiment.

[0046] Fig.15 It is an exploded perspective view of an OIS movable portion according to the second embodiment.

[0047] Fig.16A , Fig. 16B It is a diagram showing a state in which the first stage unit, the AF driving unit, and the AF supporting unit according to the second embodiment are assembled.

[0048] Fig.17 This is a diagram of a drive unit for vibration driving.

[0049] Fig.18A , Fig.18B This is a diagram of a drive unit for vibration driving.

[0050] Fig.19 This is a diagram of a drive unit for vibration driving.

[0051] Fig. 20 This is a diagram showing a drive signal when the shape of a drive pulse is adjusted and a vibration amplitude generated as a result of the adjustment.

[0052] Fig.21 This is a diagram showing a drive signal when the presence of a drive pulse is adjusted and a vibration amplitude generated as a result of the adjustment.

[0053] Fig. 22 : is a graph showing the dependency of the driving speed v on the pulse duty ratio dp.

[0054] Fig.23 : is a graph showing the dependency of the driving speed v on the excitation frequency f.

[0055] Fig.24 is a flowchart showing a driving method of the driving unit.

[0056] Fig.25A , Fig.25B FIG. 1 is a diagram showing a car as a camera mounting device on which a vehicle-mounted camera module is mounted. DETAILED DESCRIPTION

[0057] Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

[0058] [First embodiment]

[0059] 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.

[0060] The smartphone M has a dual-lens camera consisting of two rear cameras OC1 and OC2. In the present embodiment, the camera module A is applied to the rear cameras OC1 and OC2.

[0061] The camera module A has an AF (Automatic Focus) function and an OIS (Optical Image Stabilization) function, which can automatically focus on the subject when shooting, and can optically correct the shake (vibration) generated during shooting to shoot an unblurred image.

[0062] Figure 2 This is a perspective view of the appearance of camera module A. Figure 3A , Figure 3B It is an external perspective view of the lens driving device 1 according to the first embodiment. Figure 3B Show that Figure 3A The state after rotating 180° around the Z axis. Figure 2 , Figure 3A and Figure 3BAs shown, in this embodiment, the description is made using an orthogonal coordinate system (X, Y, Z). In the following drawings, the same orthogonal coordinate system (X, Y, Z) is also used for illustration.

[0063] For example, the camera module A is mounted in such a manner that the X direction becomes the up-down direction (or the left-right direction), the Y direction becomes the left-right direction (or the up-down direction), and the Z direction becomes the front-back direction when the smartphone M actually takes a picture. That is, the Z direction is the optical axis direction, the upper side (+Z side) in the figure is the light receiving side 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 referred to as "directions orthogonal to the optical axis", and the XY plane is referred to as the "plane orthogonal to the optical axis".

[0064] like Figure 2 , Figure 3A and Figure 3B As shown, the camera module A includes a lens driving device 1 for realizing AF function and OIS function, a lens unit 2 in which a lens is housed in a cylindrical lens barrel, a camera unit (not shown) for photographing an image of a subject formed by the lens unit 2, and a cover 3 for covering the whole.

[0065] The cover 3 is a covered quadrangular cylinder that is rectangular in shape when viewed from above in the direction of the optical axis. In the present embodiment, the cover 3 is square in shape when viewed from above. The cover 3 has a substantially circular opening 3a on the upper surface. The lens portion 2 faces outward from the opening 3a and is configured to protrude toward a position closer to the light receiving side than the opening surface of the cover 3 as it moves in the direction of the optical axis. The cover 3 is fixed to the base 21 of the OIS fixing portion 20 of the lens driving device 1 by, for example, bonding (see FIG. 2 ). Figure 4 ).

[0066] The imaging unit (not shown in the figure) is arranged on the imaging side of the optical axis direction of the lens driving device 1. The imaging unit (not shown in the figure) has, for example, an image sensor substrate and an imaging element mounted on the image sensor substrate. The imaging element is composed of, for example, a CCD (charge-coupled device) type image sensor, a CMOS (complementary metal oxide semiconductor) type image sensor, etc. The imaging element captures the image of the subject formed by the lens unit 2. The lens driving device 1 is mounted on the image sensor substrate (not shown in the figure) and is mechanically and electrically connected thereto. The control unit that performs drive control of the lens driving device 1 can be provided on the image sensor substrate or on a camera-mounted device (in this embodiment, a smartphone M) that mounts the camera module A.

[0067] Figure 4 , Figure 5It is an exploded perspective view of the lens driving device 1 according to the first embodiment. Figure 5 Show that Figure 4 The state after rotating 180° around the Z axis.

[0068] like Figure 4 , Figure 5 As shown, in this embodiment, the lens driving device 1 includes an OIS movable portion 10 (second movable portion), an OIS fixed portion 20 (second fixed portion), an OIS driving portion 30 (XY direction driving portion), and an OIS supporting portion 40 (second supporting portion). Figure 5 In FIG. 1 , a portion of the wiring 24 buried in the base 21 is indicated by a dotted line.

[0069] The OIS movable part 10 is a part that swings in a plane orthogonal to the optical axis during shake correction. The OIS movable part 10 includes an AF unit, a second stage 13, and a ball 42. The AF unit includes an AF movable part 11 (first movable part), a first stage 12 (first fixed part), an AF driving part 14 (Z-direction driving part), and an AF support part 15 (first support part) (see Figure 7 to Figure 9 ).

[0070] 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.

[0071] The OIS movable part 10 is spaced apart from the OIS fixed part 20 in the optical axis direction and connected to the OIS fixed part 20 via the OIS support part 40. The OIS urging members 50 provided at the four corners urge the OIS movable part 10 and the OIS fixed part 20 toward each other.

[0072] In addition, in the present embodiment, regarding the movement in the Y direction, the entire OIS movable portion 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 fixing portion 20, and the ball 42 functions as the OIS supporting portion 40.

[0073] The base 21 is a component formed of a molding material such as polyarylate (PAR), a PAR alloy (PAR Alloy, for example, PAR / PC) formed by mixing a plurality of resin materials including PAR, or a liquid crystal polymer, and is rectangular in plan view and has a circular opening 21a in the center.

[0074] The base 21 includes a first base portion 21b forming a main surface of the base 21 and a second base portion 21c formed at one of the four corners, and a recess is formed between the first base portion 21b and the second base portion 21c. The sensor substrate 22 is arranged in the recess, and the first base portion 21b, the second base portion 21c and the sensor substrate 22 form an aligned base surface.

[0075] The base 21 has an OIS motor fixing portion 21d at a diagonal portion of the second base portion 21c where the second OIS driver 30Y is disposed. The OIS motor fixing portion 21d is formed to protrude from the first base portion 21b toward the light receiving side in the optical axis direction and has a shape capable of holding the second OIS driver 30Y.

[0076] The base 21 is provided with a terminal metal fitting 23 and wiring 24, for example, by insert molding. The wiring 24 includes power supply lines for the AF drive unit 14 and the OIS drive unit 30. The wiring 24 is exposed from openings 21g formed at four corners of the base 21 and is electrically connected to the OIS force applying member 50. Power is supplied to the AF drive unit 14 and the first OIS drive unit 30X via the OIS force applying member 50. The terminal metal fitting 23 is electrically connected to wiring (not shown) formed on the sensor substrate 22.

[0077] In addition, the base 21 has ball receiving parts 21e and 21f for receiving the balls 41. The ball receiving part 21e formed in the second base part 21c is formed as a circular depression, and the three ball receiving parts 21f formed in the first base part 21b are formed as rectangular depressions extending in the Y direction. The side surface of the ball receiving part 21f is formed in a tapered shape so that the groove width becomes narrower as it approaches the bottom surface side.

[0078] The sensor substrate 22 has wiring (not shown) including power supply lines and signal lines for the magnetic sensors 25X and 25Y. The magnetic sensors 25X and 25Y are mounted on the sensor substrate 22. The magnetic sensors 25X and 25Y are composed of, for example, Hall elements or TMR (Tunnel Magneto Resistance) sensors, and are electrically connected to the terminal metal fittings 23 via wiring (not shown) formed on the sensor substrate 22. Magnets 16X and 16Y are arranged on the first stage 12 of the OIS movable part 10 at positions opposite to the magnetic sensors 25X and 25Y. The position of the OIS movable part 10 in the X direction and the Y direction is detected by a position detection unit composed of the magnetic sensors 25X and 25Y and the magnets 16X and 16Y. In addition, the position of the OIS movable part 10 in the X direction and the Y direction may be detected by an optical sensor such as an optical reflector instead of the magnets 16X and 16Y and the magnetic sensors 25X and 25Y.

[0079] The OIS force applying member 50 is composed of, for example, a helical tension spring, and connects the OIS movable part 10 and the OIS fixed part 20. In the present embodiment, one end of the OIS force applying member 50 is connected to the wiring 24 of the base 21, and the other end is connected to the wiring 17 of the first stage 12. The OIS force applying member 50 bears the tensile load when the OIS movable part 10 and the OIS fixed part 20 are connected, and acts in a manner that brings the OIS movable part 10 and the OIS fixed part 20 closer to each other. That is, the OIS movable part 10 is maintained in a state where it can swing in the XY plane in a state where it is forced by the OIS force applying member 50 along the optical axis direction (a state where it is pressed against the base 21). Thus, the OIS movable part 10 can be maintained in a stable state without shaking.

[0080] In addition, in the present embodiment, the OIS urging member 50 functions as a power supply line to the AF driving section 14 and the first OIS driving section 30X.

[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 four balls 41 interposed between the OIS movable part 10 (the first stage 12 and the second stage 13) and the base 21. One ball 41 disposed in the ball receiving part 21e of the base 21 is interposed between the base 21 and the first stage 12, and three balls 41 disposed in the ball receiving part 21f are interposed between the base 21 and the second stage 13.

[0082] In addition, the OIS support portion 40 includes three balls 42 (see FIG. 1 ) interposed between the first stage 12 and the second stage 13 in the OIS movable portion 10. Figure 7 wait).

[0083] In this embodiment, the OIS movable part 10 can be swung with high accuracy in the XY plane by limiting the rotatable directions of the balls 41 and 42 (seven in total) constituting the OIS support part 40. The number of the balls 41 and 42 constituting the OIS support part 40 can be changed as appropriate.

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

[0085] The first OIS driving unit 30X and the second OIS driving unit 30Y are composed of ultrasonic motors. The first OIS driving unit 30X is fixed to the OIS motor fixing unit 12f of the first stage 12 in a manner extending along the X direction. The second OIS driving unit 30Y is fixed to the OIS motor fixing unit 21d of the base 21 in a manner extending along the Y direction. That is, the first OIS driving unit 30X and the second OIS driving unit 30Y are arranged along sides orthogonal to each other.

[0086] The structure of the OIS driving unit 30 is as follows Fig. 6A , Figure 6B shown. Fig. 6A 2 shows the state in which the components of the OIS driving unit 30 are assembled. Figure 6B 2 shows a state where the components of the OIS driving unit 30 are disassembled. Fig. 6A , Figure 6B The second OIS driving unit 30Y is shown, but the main structure of the first OIS driving unit 30X, specifically, the structure except the shape of the OIS resonance unit 31 and the electrode 33, is the same as that of the second OIS driving unit 30Y, so Fig. 6A , Figure 6B It is considered to be a diagram showing the OIS driving unit 30.

[0087] like Fig. 6A , Figure 6B As shown, the OIS driving unit 30 includes an OIS resonance unit 31, an OIS piezoelectric element 32, and an OIS electrode 33. The driving force of the OIS driving unit 30 is transmitted to the second stage 13 via the OIS power transmission unit 34. Specifically, the first OIS driving unit 30X is connected to the first OIS power transmission unit 34X, and the second OIS driving unit 30Y is connected to the second OIS power transmission unit 34Y.

[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.

[0089] The OIS electrode 33 sandwiches the OIS resonance unit 31 and the OIS piezoelectric element 32 to apply a voltage to the OIS piezoelectric element 32. The OIS electrode 33 of the first OIS driver 30X is electrically connected to the power supply board 18, and the OIS electrode 33 of the second OIS driver 30Y is electrically connected to the wiring 24 of the chassis 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 31a sandwiched by the OIS piezoelectric element 32, two arm parts 31b extending from the upper and lower parts of the body 31a, a protrusion 31c extending from the central part of the body 31a in the Y direction, and a power-carrying part 31d extending from the central part of the body 31a to the side opposite to the protrusion 31c. The two arm parts 31b have a symmetrical shape, and their free ends abut against the OIS power transmission part 34, and resonate with the vibration of the OIS piezoelectric element 32 and deform symmetrically. The power-carrying part 31d of the first OIS driving part 30X is electrically connected to the wiring 17 of the first stage 12, and the power-carrying part 31d of the second OIS driving part 30Y is electrically connected to the wiring 24 of the base 21.

[0091] The OIS piezoelectric element 32 is attached to the body 31a of the OIS resonance part 31 in the thickness direction and is sandwiched by the OIS electrode 33 so that they are electrically connected to each other. For example, one end of the power supply path is connected to the OIS electrode 33, and the other end is connected to the power supply part 31d of the OIS resonance part 31, thereby applying a voltage to the OIS piezoelectric element 32 to generate vibration.

[0092] The OIS resonance part 31 has at least two resonance frequencies, and deforms in different motions at each resonance frequency. In other words, the overall shape of the OIS resonance part 31 is set so that the OIS resonance part 31 deforms in different motions corresponding 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.

[0093] The OIS power transmission part 34 is a clamping guide extending in one direction, one end of which is connected to the OIS driving part 30, and the other end of which is connected to the second table 13. The OIS power transmission part 34 has an OIS motor abutment part 34a, a table fixing part 34c, and a connecting part 34b. The OIS motor abutment part 34a is formed so that its cross section is roughly U-shaped and abuts against the free end of the arm part 31b of the OIS resonance part 31. The table fixing part 34c is arranged at the end of the OIS power transmission part 34 and is fixed to the OIS clamping guide fixing part 13c of the second table 13 (see Figure 8 The connecting portion 34b is a portion connecting the OIS motor contact portion 34a and the table fixing portion 34c, and is branched from the table fixing portion 34c into two portions, and the two portions are formed parallel to each other.

[0094] The width between the OIS motor abutment portions 34a is set to be wider than the width between the free ends of the arm portions 31b of the OIS resonance portion 31. Thus, when the OIS power transmission portion 34 is mounted on the OIS drive portion 30, the OIS power transmission portion 34 functions as a leaf spring, so that the pushing force acts in the direction of expanding the arm portions 31b of the OIS resonance portion 31. By this pushing force, the OIS power transmission portion 34 is held between the free ends of the arm portions 31b of the OIS resonance portion 31, and the driving force from the OIS resonance portion 31 is efficiently transmitted to the OIS power transmission portion 34.

[0095] The OIS driving unit 30 and the OIS power transmission unit 34 only abut against each other under pressure, so there is no need to increase the size of the lens driving device 1. The moving distance (stroke) of the OIS movable unit 10 can be lengthened by simply increasing the abutting portion in the X direction or the Y direction.

[0096] The first OIS driving unit 30X is fixed to the OIS movable unit 10 (first stage 12) and connected to the second stage 13 via the OIS power transmission unit 34X. When the second OIS driving unit 30Y performs the shake correction in the Y direction, it moves together with the OIS movable unit 10. On the other hand, the second OIS driving unit 30Y is fixed to the OIS fixed unit 20 (base 21) and connected to the second stage 13 via the OIS power transmission unit 34Y. The second OIS driving unit 30Y will not be affected by the shake correction in the X direction performed by the first OIS driving unit 30X. That is, the movement of the OIS movable unit 10 performed by one OIS driving unit 30 will not be hindered by the structure of the other OIS driving unit 30. Therefore, the rotation of the OIS movable unit 10 around the Z axis can be prevented, and the OIS movable unit 10 can be swung with good accuracy in the XY plane.

[0097] Figure 7 to Figure 9 It is an exploded perspective view of the OIS movable part 10 . Figure 8 Show Figure 7 The state after rotating 180° around the Z axis. Fig. 9 It means to make Figure 7 The bottom perspective view shows the state after rotating 90 degrees around the Z axis.

[0098] like Figure 7 to Figure 9As shown in the figure, 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 part 14, and an AF supporting part 15. With respect to the movement in the Y direction, the OIS movable part 10 including the first stage 12 and the second stage 13 is a movable body as a whole, whereas with respect to the movement in the X direction, the second stage 13 functions as the OIS fixed part 20, and only the AF unit functions as the OIS movable part 10. In addition, the first stage 12 functions as the AF fixed part.

[0099] The AF movable section 11 is a portion that moves in the optical axis direction during focusing, and is disposed radially apart from the first stage section 12 (AF fixed section), and is connected to the first stage section 12 via the AF support section 15 .

[0100] The AF movable section 11 has a holding lens section 2 (see Figure 2 ) of the lens holder 111 and the AF force applying component 112.

[0101] The lens holder 111 is formed of, for example, polyarylate (PAR), PAR alloy obtained by mixing a plurality of resin materials including PAR, liquid crystal polymer, etc. The lens holder 111 has a cylindrical lens housing portion 111a. Figure 2 ) is fixed to the lens housing portion 111a by, for example, bonding.

[0102] The lens holder 111 has an upper flange 111b on the upper outer periphery of the lens receiving portion 111a, and a lower flange 111c on the lower outer periphery. In the present embodiment, four upper flanges 111b are provided at positions corresponding to the four corners of the lens driving device 1, and a lower flange 111c is provided below two opposing upper flanges 111b. The upper flange 111b functions as a limiting portion that limits the movement of the lens holder 111 toward the imaging side (lower side) in the optical axis direction, and the lower flange 111c functions as a limiting portion that limits the movement of the lens holder 111 toward the light receiving side (upper side) in the optical axis direction.

[0103] In addition, the lens holder 111 has a ball receiving portion 111d on the peripheral surface of the lens receiving portion 111a for receiving the AF support portion 15. In the present embodiment, the ball receiving portion 111d is provided at two locations line-symmetrically about one diagonal direction (the middle direction between the X direction and the Y direction) so as to open on the same side (the side opposite to the side where the AF biasing member 112 is arranged) with respect to the other diagonal direction.

[0104] The AF force applying member 112 is formed of a metal material such as titanium copper, nickel copper, stainless steel, etc., and is arranged so as to extend in the circumferential direction of the lens holder 111. In the present embodiment, the AF force applying member 112 is formed by, for example, bending a metal plate, and has a leaf spring portion 112a extending in directions orthogonal to each other and a connecting portion 112b connecting the leaf spring portions 112a. The leaf spring portion 112a has a shape symmetrical with respect to the connecting portion 112b, and an end portion 112c of the leaf spring portion 112a is formed to be folded back into a substantially U-shape (hereinafter referred to as "AF motor abutment portion 112c").

[0105] The AF urging member 112 is fixed to the lens holder 111 by attaching the connecting portion 112b to one side of the space sandwiched between the upper flange 111b and the lower flange 111c of the lens holder 111. The leaf spring portion 112a extends in the X direction and the Y direction.

[0106] The first stage 12 is a portion that supports the AF movable section 11 via the AF support section 15. The second stage 13 is disposed on the imaging side of the first stage 12 in the optical axis direction via the ball bearing 42. The first stage 12 moves in the X direction and the Y direction during shake correction, and the second stage 13 moves only in the X direction during shake correction.

[0107] The first stage 12 is a substantially rectangular cylindrical member, and is formed of, for example, a liquid crystal polymer. The first stage 12 has a substantially circular opening 12a at a portion corresponding to the lens holder 111. In the first stage 12, two side walls corresponding to the second stage 13 are formed to be thinner than the other side walls by an amount less than the thickness of the second stage.

[0108] The first platform 12 has three ball receiving portions 12b for receiving the balls 42 and a ball receiving portion 12c for receiving the balls 41 on the lower surface. The ball receiving portion 12b is formed as an oblong depression extending in the X direction. In addition, the side surface of the ball receiving portion 12b is formed in a tapered shape in such a way that the groove width narrows as it approaches the bottom surface side. The ball receiving portion 12c is formed as a circular depression. The ball receiving portion 12b is opposite to the ball receiving portion 13a of the second platform 13 in the Z direction, and the ball receiving portion 12c is opposite to the ball receiving portion 21e of the base 21 in the Z direction.

[0109] The first platform 12 has flanges 12d protruding inward at the four corners of the lower portion. When the lens holder 111 is mounted on the first platform 12, the upper flange 111b of the lens holder 111 is located above the flange 12d, and the lower flange 111c of the lens holder 111 is located below the two flanges 12d at the diagonal positions. In other words, the two flanges 12d are sandwiched by the upper flange 111b and the lower flange 111c of the lens holder 111 with a movable distance of the lens holder 111 spaced apart.

[0110] The first stage 12 has a ball fixing portion 12e for fixing the AF support portion 15 on the inner side surface of one of the side walls along the X direction and the inner side surface of one of the side walls along the Y direction. The first stage 12 has an OIS motor fixing portion 12f for fixing the first OIS driving portion 30X on the outer side surface of the side wall along the X direction. In the first stage 12, the side wall along the Y direction is formed so that the outer side surface is recessed inward, and when the lens driving device 1 is assembled, the second OIS driving portion 30Y is located on the outer side surface of the side wall along the Y direction.

[0111] In addition, in the first stage 12, AF driving units 14A and 14B are arranged on the inner side surface of the other side wall along the X direction and the inner side surface of the other side wall along the Y direction, and magnets 16X and 16Y for detecting XY positions are arranged on the lower surfaces of these side walls so as to face the magnetic sensors 25X and 25Y in the Z direction. For example, the magnet 16X is magnetized in the X direction, and the magnet 16Y is magnetized in the Y direction.

[0112] In the first stage portion 12, a wiring 17 is embedded, for example, by insert molding. The wiring 17 is exposed from the notch portions of the outer surface of the four corners of the first stage portion 12, and one end of the OIS urging member 50 is connected to the portion. In addition, a power supply board 18 electrically connected to the wiring 17 is arranged on the upper surface of the first stage portion 12. Power is supplied to the AF driving unit 14 and the first OIS driving unit 30X via the wiring 17 and the power supply board 18.

[0113] The second stage 13 is an L-shaped component, for example, formed of a liquid crystal polymer. The inner peripheral surface of the second stage 13 is formed in an arc shape along the outer shape of the lens holder 111. The outer side surface of the side wall of the second stage 13 along the Y direction is formed to be recessed inwardly in the same manner as the first stage 12, and when the lens driving device 1 is assembled, the second OIS driving unit 30Y is located on the outer side surface of the side wall of the second stage 13 along the Y direction. In the present embodiment, the second stage 13 is formed in an L shape and is arranged below the two side walls formed in the first stage 12 with a relatively thin thickness, thereby achieving a low height of the OIS movable part 10.

[0114] The second platform 13 has three ball receiving portions 13a on the lower surface for receiving the balls 41. The ball receiving portions 13a are opposite to the ball receiving portions 21f of the base 21. The ball receiving portions 13a are formed as oblong depressions extending in the Y direction. In addition, the side surfaces of the ball receiving portions 13a are formed in a tapered shape so that the groove width becomes narrower as it approaches the bottom surface side.

[0115] In addition, the second platform 13 has three ball receiving portions 13b on the upper surface for receiving the balls 42. The ball receiving portions 13b are opposite to the ball receiving portions 12b of the first platform 12 in the Z direction. The ball receiving portions 13b are formed as oblong recesses extending in the X direction. The side surfaces of the ball receiving portions 12b are formed in a tapered shape so that the groove width narrows as it approaches the bottom surface side.

[0116] The three balls 41 constituting the OIS support portion 40 are held in a multi-point contact manner by the ball receiving portion 21f of the base 21 and the ball receiving portion 13a of the second stage portion 13. Therefore, the balls 41 are stably rotated in the X direction.

[0117] In addition, the balls 42 are held in multi-point contact by the ball receiving portion 13b of the second stage 13 and the ball receiving portion 12b of the first stage 12. Therefore, the balls 42 are stably rotated in the X direction.

[0118] The AF support part 15 is composed of balls. In the present embodiment, three balls are arranged side by side in the Z direction. The AF support part 15 is rotatably interposed between the ball receiving part 111 d of the lens holder 111 and the ball fixing part 12 e of the first stage part 12 .

[0119] The AF drive unit 14 is an actuator that moves the AF movable unit 11 in the Z direction. The AF drive unit 14 is composed of a first AF drive unit 14A (first Z direction drive unit) and a second AF drive unit 14B (second Z direction drive unit). The AF drive unit 14 is composed of an ultrasonic motor, similar to the OIS drive unit 30. The first AF drive unit 14A and the second AF drive unit 14B are fixed to the inner circumferential surface of the first stage 12 in a manner along the X direction and the Y direction, respectively.

[0120] The structure of the AF driving unit 14 is as follows: Fig. 10A , Fig. 10B shown. Fig. 10A FIG. 2 shows a state where the components of the AF driving unit 14 are assembled. Fig. 10B FIG. 1 shows a state where the components of the AF driving unit 14 are disassembled. Fig. 10A , Fig. 10B The second AF driving unit 14B is shown, but the main structure of the first AF driving unit 14A, specifically, the structure except the shape of the AF electrode 143, is the same as that of the second AF driving unit 14B, so Fig. 10A , Fig. 10B It is considered to be a diagram showing the AF driving section 14. The structure of the AF driving section 14 is almost the same as that of the OIS driving section 30.

[0121] like Fig. 10A , Fig. 10BAs shown in FIG. 1 , the AF driving section 14 includes an AF resonance section 141 , an AF piezoelectric element 142 , and an AF electrode 143 . The driving force of the AF driving section 14 is transmitted to the lens holder 111 via the AF urging member 112 .

[0122] 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 .

[0123] 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 .

[0124] 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. In the present embodiment, the AF resonance part 141 has a substantially rectangular body 141a sandwiched by the AF piezoelectric element 142, two arm parts 141b extending from the upper and lower parts of the body 141a in the X direction or the Y direction, a protrusion 141c extending from the central part of the body 141a in the X direction or the Y direction, and a current-carrying part 141d extending from the central part of the body 141a to the side opposite to the protrusion 141c and electrically connected to the power supply path (wiring 17 of the first stage 12). The two arm parts 141b have symmetrical shapes except for the free ends, and resonate with the vibration of the AF piezoelectric element 142 and deform symmetrically. The free ends of the two arm parts 141b have different shapes from each other so that only one free end abuts against the AF force applying member 112. Furthermore, as long as the shape of the AF urging member 112 can be somehow adjusted so that only one free end portion contacts the AF urging member 112 , the free ends of the two arm portions 141 b may have symmetrical shapes.

[0125] 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. The power supply plate 18 is connected to the AF electrode 143, and the wiring 17 of the first stage portion 12 is connected to the power supply portion 141d of the AF resonance portion 141, thereby applying a voltage to the AF piezoelectric element 142 to generate vibration.

[0126] The AF resonance portion 141 has at least two resonance frequencies, similar to the OIS resonance portion 31, and deforms in different motions at each resonance frequency. In other words, the overall shape of the AF resonance portion 141 is set so that the AF resonance portion 141 deforms in different motions corresponding to the two resonance frequencies.

[0127] The first AF driving section 14A and the second AF driving section 14B are fixed to the inner peripheral surface of the first stage 12 in a manner along the X direction and the Y direction, respectively. In the present embodiment, in the first AF driving section 14A and the second AF driving section 14B, the front end of one of the two arm sections 141b (for example, the arm section 141b located on the lower side) is brought into contact with the AF force member 112, so that the AF movable section 11 is moved in the Z direction. The arm section 141b that is brought into contact with the AF force member 112 is referred to as the "first arm section 141b", and the arm section 141b that is not brought into contact with the AF force member 112 is referred to as the "second arm section 141b". In addition, if the front ends of both the upper and lower arm sections 141b of the AF resonance section 141 are brought into contact with the AF force member 112, since the two arm sections 141b move symmetrically, sliding occurs and the AF movable section 11 cannot be moved in the Z direction.

[0128] In this embodiment, the AF driving unit 14 moves the AF movable unit 11 (AF force applying member 112) in the Z direction by only bringing the first arm 141b into contact with the AF movable unit 11, so that the driving force transmitted is halved compared to the case where the driving force is transmitted using two arms 31b as in the OIS driving unit 30. Therefore, by providing two AF driving units 14, the driving force for movement in the optical axis direction is ensured.

[0129] When the AF unit is assembled and the AF driving section 14 is brought into contact with the AF urging member 112, the AF urging member 112 functions as a leaf spring, and the AF movable section 11 (lens holder 111) is urged toward the first stage section 12 (AF fixing section) via the AF support section 15 (see FIG. 1 ). Fig.11A , Fig. 11B ).

[0130] Specifically, the first arm 141b of the first AF driving unit 14A and the second AF driving unit 14B abuts against both ends of the AF force applying member 112, so that the lens holder 111 is forced in one direction in the plane orthogonal to the optical axis relative to the first stage (AF fixing portion). In the embodiment, the lens holder 111 is pressed by the AF force applying member 112, so that it is forced in the middle direction between the X direction and the Y direction relative to the first stage (AF fixing portion).

[0131] By this force, the AF force applying member 112 is pressed against the front end of the arm portion 141b of the AF resonance portion 141, and the driving force from the AF resonance portion 141 is efficiently transmitted to the AF force applying member 112. In addition, the AF force applying member 112 has both the function of transmitting the driving force of the AF drive portion 14 and the function of applying force to the AF movable portion 11 toward the first stage portion 12, so the component structure is simplified.

[0132] The AF support parts 15 are provided at two locations corresponding to the first AF drive part 14A and the second AF drive part 14B. The AF movable part 11 is urged toward the first stage part 12 via the AF support parts 15 provided at two locations, so that the AF movable part 11 is held in a stable posture.

[0133] The AF driving section 14 and the AF urging member 112 only come into contact with each other under pressure, so by increasing the contact portion in the Z direction, the moving distance (stroke) of the AF movable section 11 can be easily lengthened without hindering the low height of the lens driving device 1. However, the moving distance of the AF movable section 11 is limited to a degree that the AF urging member 112 does not come into contact with the other arm 141b (for example, the arm 141b located on the upper side) of the AF resonance section 141 that does not interfere with the movement of the AF movable section 11.

[0134] The first arm 141b of the AF resonance unit 141 contacts the metal molded AF urging member 112. This allows the driving force of the AF driving unit 14 to be efficiently transmitted compared to when the first arm 141b contacts the resin molded lens holder 111.

[0135] In the lens driving device 1, when a voltage is applied to the AF driving unit 14, the AF piezoelectric element 142 vibrates, and the AF resonance unit 141 deforms in accordance with the frequency. At this time, the voltage is applied so that the first AF driving unit 14A and the second AF driving unit 14B exhibit the same action. The AF force applying member 112 slides in the Z direction by the driving force of the AF driving unit 14. With this, the AF movable unit 11 moves in the Z direction, thereby focusing. The AF support unit 15 is composed of a ball, so that the AF movable unit 11 can move smoothly in the Z direction.

[0136] In the lens driving device 1, when a voltage is applied to the OIS driving unit 30, the OIS piezoelectric element 32 vibrates, and the OIS resonance unit 31 deforms in accordance with the frequency. The OIS power transmission unit 34 slides in the X direction or the Y direction by the driving force of the OIS driving unit 30. As a result, the OIS movable unit 10 moves in the X direction or the Y direction, thereby performing shake correction. The OIS support unit 40 is composed of a ball, so that the OIS movable unit 10 can move smoothly in the X direction or the Y direction.

[0137] Specifically, when the first OIS 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 on which the first OIS driving unit 30X is configured to the second stage 13. At this time, the ball 41 (three balls accommodated in the ball accommodation portion 21f) clamped by the second stage 13 and the base 21 cannot rotate in the X direction, so the position of the second stage 13 relative to the base 21 in the X direction remains unchanged. On the other hand, the ball 42 clamped by the first stage 12 and the second stage 13 can rotate in the X direction, so the first stage 12 moves relative to the second stage 13 in the X direction. That is, the second stage 13 constitutes the OIS fixed part 20, and the first stage 12 constitutes the OIS movable part 10.

[0138] In addition, when the second OIS driving unit 30Y is driven and the OIS power transmission unit 34 moves in the Y direction, power is transmitted from the base 21 on which the second OIS driving unit 30Y is configured to the second stage 13. At this time, the ball 42 clamped by the first stage 12 and the second stage 13 cannot rotate in the Y direction, so the position of the first stage 12 relative to the second stage in the Y direction remains unchanged. On the other hand, the ball 41 (three balls accommodated in the ball accommodating portion 21f) clamped by the second stage 13 and the base 21 can rotate 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.

[0139] In this way, the OIS movable part 10 swings in the XY plane, thereby performing shake correction. Specifically, based on the detection signal indicating the angular shake from the shake detection unit (for example, a gyro sensor, not shown in the figure), the energization voltage of the OIS driving unit 30X, 30Y is controlled in such a way 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, 16Y and the magnetic sensors 25X, 25Y, the translation movement of the OIS movable part 10 can be accurately controlled.

[0140] As described above, the lens driving device 1 of the embodiment includes: the first stage 12 (first fixed part); the AF movable part 11 (first movable part) arranged to be spaced apart from the first stage 12; the AF support part 15 (first support part) supporting the AF movable part 11 relative to the first stage 12; and the AF driving part 14 (Z-direction driving part) arranged on the first stage 12 and moving the AF movable part 11 relative to the first stage 12 in the optical axis direction. The AF driving part 14 is composed of an ultrasonic motor having an AF piezoelectric element 142 and an AF resonance part 141 and converting vibration motion into linear motion. The AF resonance part 141 has a body part 141a sandwiched by the AF piezoelectric element 142, and a first arm part and a second arm part 141b extending in the same direction from the body part 141a. The first arm part and the second arm part 141b deform in resonance with the vibration of the AF piezoelectric element, and only the first arm part 141b contacts the AF movable part 11.

[0141] According to the lens driving device 1, the AF driving unit 14 is composed of an ultrasonic motor, so the influence of external magnetism can be reduced, and miniaturization and low height can be achieved. Therefore, even if the camera module A with the lens driving device 1 is arranged close to each other like a smartphone M, there will be no magnetic influence, so it is very suitable for use in a dual-lens camera.

[0142] In addition, in the lens driving device 1 , the AF movable section 11 is urged toward the first stage section (AF fixed section) via the AF support section 15 , thereby allowing the driving force of the AF driving section 14 to be efficiently transmitted to the AF movable section 11 .

[0143] [Second embodiment]

[0144] Fig. 12A , Fig. 12B It is an external perspective view of a lens driving device 1A according to a second embodiment. Fig. 12B Show that Fig. 12A The state after rotating 180° around the Z axis. Except for the structure of the OIS movable part 10A, the lens driving device 1A of the second embodiment is almost the same as the lens driving device 1 of the first embodiment. The same or corresponding components as those of the lens driving device 1 of the first embodiment are marked with the same reference numerals and the description is omitted. Here, the OIS movable part 10A (especially the AF movable part 51) is described.

[0145] Figure 13 to Figure 15 It is an exploded perspective view of the OIS movable part 10 . Fig.14 Show Fig.13 The state after rotating 180° around the Z axis. Fig.15 It means to make Fig.13 The bottom perspective view shows the state after rotating 90 degrees around the Z axis.

[0146] like Figure 13 to Figure 15 As shown in the second embodiment, the OIS movable section 10A includes an AF movable section 51, a first stage 12, a second stage 13, an AF driving section 14, and an AF supporting section 15. With regard to the movement in the Y direction, the OIS movable section 10A including the first stage 12 and the second stage 13 is a movable body as a whole, whereas with regard to the movement in the X direction, the second stage 13 functions as the OIS fixed section 20, and only the AF unit functions as the OIS movable section 10. In addition, the first stage 12 functions as the AF fixed section.

[0147] The AF movable section 51 is a portion that moves in the optical axis direction during focusing, and is disposed radially apart from the first stage section 12 (AF fixed section), and is connected to the first stage section 12 via the AF support section 15 .

[0148] The AF movable section 51 has a holding lens section 2 (see Figure 2 )'s lens holder 511 and AF force applying component 512.

[0149] The lens holder 511 is formed of, for example, polyarylate (PAR), PAR alloy obtained by mixing a plurality of resin materials including PAR, liquid crystal polymer, etc. The lens holder 511 has a cylindrical lens receiving portion 511a. Figure 2 ) is fixed to the lens housing portion 511a by, for example, bonding.

[0150] The lens holder 511 has an upper flange 511b at the upper outer periphery of the lens receiving portion 511a. In the second embodiment, four upper flanges 511b are provided at positions corresponding to the four corners of the lens driving device 1A. The upper flanges 511b function as a limiting portion for limiting the movement of the lens holder 511 toward the imaging side (lower side) in the optical axis direction.

[0151] A magnet receiving portion 511c is provided on one of the four upper flange portions 511b. The magnet receiving portion 511c receives the magnet 16Z for detecting the Z position. The magnet 16Z is disposed in the magnet receiving portion 511c. Figure 4 ) is disposed at a position opposite to the magnet 16Z in the optical axis direction, and a magnetic sensor (such as a Hall element, a TMR sensor, etc.) for detecting the Z position (not shown). In addition, instead of the magnet 16Z and the magnetic sensor (not shown), an optical sensor such as a photo reflector may be used to detect the position of the AF movable part 51 in the Z direction.

[0152] In addition, the lens holder 511 has a ball receiving portion 511d on the peripheral surface of the lens receiving portion 511a for receiving the AF support portion 15. In the second embodiment, the ball receiving portion 511d is provided at two locations line-symmetrical about one diagonal direction (the middle direction between the X direction and the Y direction) so as to open on the same side (the side where the AF biasing member 512 is arranged) with respect to the other diagonal direction.

[0153] The AF urging member 512 is formed of a metal material such as titanium copper, nickel copper, stainless steel, etc. The AF urging member 512 is formed of a flat dumbbell-shaped leaf spring, for example. The AF driving parts 14A and 14B abut against both end portions 512a in the length direction of the AF urging member 512. In addition, the spring constant of the AF urging member 512 is adjusted by reducing the weight.

[0154] The AF urging member 512 is disposed in a space 511e formed between the magnet housing portion 511c and the lens housing portion 511a, and is sandwiched between the spacer 513 and the magnet housing portion 511c. The AF urging member 512 extends so as to contact the lens housing portion 511a.

[0155] The first AF driving section 14A and the second AF driving section 14B are fixed to the inner peripheral surface of the first stage 12 in a manner along the X direction and the Y direction, respectively. In the second embodiment, in the first AF driving section 14A and the second AF driving section 14B, the front end of one of the two arm portions 141b (for example, the arm portion 141b located on the upper side) is brought into contact with the AF force member 512, so that the AF movable section 51 is moved in the Z direction. The arm portion 141b that is brought into contact with the AF force member 512 is referred to as the "first arm portion 141b", and the arm portion 141b that is not brought into contact with the AF force member 112 is referred to as the "second arm portion 141b". In addition, if the front ends of both the upper and lower arm portions 141b of the AF resonance section 141 are brought into contact with the AF force member 112, since the two arm portions 141b move symmetrically, sliding occurs and the AF movable section 11 cannot be moved in the Z direction.

[0156] In the second embodiment, the AF driving unit 14 moves the AF movable unit 11 (AF force applying member 112) in the Z direction by only bringing the first arm 141b into contact with the AF movable unit 11, so that the driving force transmitted is halved compared to the case where the driving force is transmitted using two arms 31b as in the OIS driving unit 30. Therefore, by providing two AF driving units 14, the driving force for movement in the optical axis direction is ensured.

[0157] When the AF unit is assembled and the AF driving section 14 is brought into contact with the AF urging member 512, the AF urging member 512 functions as a leaf spring, and the AF movable section 51 is urged toward the first stage section 12 (AF fixed section) via the AF support section 15 (see Fig.16A , Fig. 16B ).

[0158] Specifically, the first arm 141b of the first AF driving unit 14A and the second AF driving unit 14B abuts against both ends of the AF force applying member 512, so that the lens holder 111 is forced in one direction in the plane orthogonal to the optical axis relative to the first stage (AF fixing portion). In the second embodiment, the lens holder 111 is pulled by the AF force applying member 512, so that it is forced in the middle direction between the X direction and the Y direction relative to the first stage (AF fixing portion).

[0159] By this force, the AF force applying member 512 is pressed against the front end of the arm portion 141b of the AF resonance portion 141, and the driving force from the AF resonance portion 141 is efficiently transmitted to the AF force applying member 512. In addition, the AF force applying member 512 has both the function of transmitting the driving force of the AF drive portion 14 and the function of applying force to the AF movable portion 51 toward the first stage portion 12, so the component structure is simplified.

[0160] In the second embodiment, the AF urging member 512 is composed of a flat dumbbell-shaped leaf spring and exerts a large pushing force, so that the sinking caused by the weight of the AF movable part 51 is suppressed, so that the posture of the AF movable part 51 relative to the first stage part 12 is stabilized. Therefore, the driving force of the AF driving part 14 can be efficiently transmitted to the AF movable part 51, and the responsiveness is improved.

[0161] The AF supporting parts 15 are provided at two locations corresponding to the first AF driving part 14A and the second AF driving part 14B. The AF movable part 11 is urged toward the first stage 12 via the AF supporting parts 15 provided at two locations, so that the AF movable part 11 is held in a stable posture.

[0162] The AF driving section 14 and the AF urging member 512 only come into contact with each other under pressure, so by increasing the contact portion in the Z direction, the moving distance (stroke) of the AF movable section 51 can be easily lengthened without hindering the low height of the lens driving device 1A. However, the moving distance of the AF movable section 51 is limited to the extent that the AF urging member 512 does not come into contact with the other arm 141b (for example, the arm 141b located on the lower side) of the AF resonance section 141 that does not interfere with the movement of the AF movable section 51.

[0163] The first arm 141b of the AF resonance unit 141 contacts the metal molded AF urging member 512. This allows the driving force of the AF driving unit 14 to be efficiently transmitted compared to when the first arm 141b contacts the resin molded lens holder 111.

[0164] As described above, the lens driving device 1A of the second embodiment includes: the first stage 12 (first fixed portion); the AF movable portion 51 (first movable portion) arranged to be spaced apart from the first stage 12; the AF support portion 15 (first support portion) supporting the AF movable portion 51 relative to the first stage 12; and the AF driving portion 14 (Z-direction driving portion) arranged on the first stage 12 and moving the AF movable portion 51 relative to the first stage 12 in the optical axis direction. The AF driving portion 14 is composed of an ultrasonic motor having an AF piezoelectric element 142 and an AF resonance portion 141 and converting vibration motion into linear motion. The AF resonance portion 141 has a body portion 141a sandwiched by the AF piezoelectric element 142, and a first arm portion and a second arm portion 141b extending from the body portion 141a in the same direction. The first arm portion and the second arm portion 141 b deform in resonance with the vibration of the AF piezoelectric element 142 , and only the first arm portion 141 b comes into contact with the AF movable portion 51 (AF urging member 512 ).

[0165] According to the lens driving device 1A, the AF driving unit 14 is composed of an ultrasonic motor, so the influence of external magnetism can be reduced, and miniaturization and low height can be achieved. Therefore, even if the camera module A with the lens driving device 1 is arranged close to each other like a smartphone M, there will be no magnetic influence, so it is very suitable for use in a dual-lens camera.

[0166] In addition, in the lens driving device 1A, the AF movable section 51 is urged toward the first stage section (AF fixed section) via the AF support section 15. Thus, the driving force of the AF driving section 14 can be efficiently transmitted to the AF movable section 51.

[0167] [Drive unit control method]

[0168] In the lens driving device 1 of the first embodiment and the lens driving device 1A of the second embodiment, for example, the AF driving section 14 and the OIS driving section 30 (driving unit) are controlled as follows. In the driving unit shown below, the "active element C-1" corresponds to the AF resonance section 141 and the OIS resonance section 31, and the "passive element C-4" corresponds to the AF force applying member 112, 512 and the OIS power transmission section 34.

[0169] In principle, identical or functionally identical parts are provided with the same reference symbols in the Figures. Fig.17The driving unit having an active element C-1 is shown. The active element C-1 has a resonator C-2 (corresponding to the AF resonance part 141 and the OIS resonance part 31), and the resonator C-2 has a pair of arms, namely, a first arm C-21 and a second arm C-22. The arms C-21, C-22 and the mounting part C-14 are connected to the connecting part C-20 of the resonator C-2. The resonator C-2 is mounted on other parts such as a base element by means of the mounting part C-14.

[0170] An excitation unit C-23 such as a piezoelectric element (corresponding to the AF piezoelectric element 142 and the OIS piezoelectric element 32) is arranged on the connecting portion C-20. The controller C-90 is arranged in a manner to generate an excitation signal or an excitation voltage for driving the excitation unit C-23. The sensor C-91 is arranged in a manner to measure the position and / or speed of the passive element C-4 relative to the active element C-1. The sensor C-91 measures the position and / or speed of the passive element C-4 based on the magnetic field affected by the position of the passive element C-4. A Hall sensor can be applied as the sensor C-91.

[0171] The excitation unit C-23 has two separate elements arranged on both sides of the excitation unit C-23. The resonator C-2 and the excitation unit C-23 are flat elements, which are stacked on each other and extend parallel to the reference plane C-28 (see Fig.19 ).

[0172] If excited by an AC voltage of an excitation frequency, the arms C-21 and C-22 vibrate, and the first contact portion C-31 of the first arm C-21 performs a roughly linear motion corresponding to the frequency. The linear vibration can have orthogonal components, and the overall motion can be regarded as an ellipse. The direction of the linear vibration (forward and backward) motion changes according to the frequency. The first contact portion C-31 repeatedly contacts the first contact area C-41 of the passive element C-4, driving the first contact area C-41 relative to the active element C-1. The same is true for the second contact portion C-32 and the second contact area C-42.

[0173] Corresponding to the direction of the linear forward and backward movement, the passive element C-4 is repeatedly pressed in the corresponding direction and, corresponding to how the passive element C-4 is suspended, performs, for example, a linear and / or rotational movement. Fig.17 In the illustrated embodiment, the passive element C-4 rotates relative to the active element C-1.

[0174] According to the specific geometric shapes of these parts and the configuration of the passive element C-4 moving relative to the active element C-1, for the desired (rotational or linear) direction of movement, the excitation frequency that brings the maximum energy transfer to the desired movement can be determined for each vibration or each pulse and each pressing movement generated therefrom. In order to reduce the energy transfer of each pulse, the excitation frequency can be slightly changed so that the vibration movement changes slightly but the general direction remains the same. As a result, the abutment angles at which the first contact portion C-31 and the second contact portion C-32 abut against each contact area C-41, C-42, and the amplitudes of their vibrations change, and as a result, the energy transferred by each pulse is reduced compared to the optimal angle. In this way, the movement speed of the passive element C-4 can be controlled by using a slight relative change in the excitation frequency.

[0175] The prestress acts between the first contact portion C-31 and the first contact area C-41, and between the second contact portion C-32 and the second contact area C-42. The prestress is generated by the elasticity of the first arm C-21 and the second arm C-22. If the passive element C-4 is arranged between the first contact portion C-31 and the second contact portion C-32, the first arm C-21 and the second arm C-22 are pressed in the direction of separation from each other.

[0176] The first arm C-21 and the second arm C-22 extend from the connection part C-20 in a substantially symmetrical manner, but when they are manufactured from a flat sheet of material, their shapes, especially the fine details of the outline, may sometimes be different. The resonator axis C-24 corresponds to the following symmetry axis, which is a symmetry axis that can mirror the resonator C-2, especially the connection part C-20 and the first arm C-21 and the second arm C-22 except for the fine details of the above-mentioned arms. When excited by the excitation unit C-23, the movement of the connection part C-20 and the arms C-21 and C-22 is roughly symmetrical about the same symmetry axis. The node of this movement, that is, the minimum movement area, is located on the resonator axis C-24. The mounting part C-14 for mounting the active element C-1 on other elements is also located on the resonator axis C-24.

[0177] Fig.18A , Fig.18B The deformation state of the active element C-1 is shown, and the passive element C-4 is omitted for ease of observation. Fig.18A Show Fig.17 Active element C-1 is shown. Fig.18B In the figure, as indicated by the double-headed arrow corresponding to the resonator axis C-24, the active element C-1 is positioned so that the passive element is driven in a straight line, especially in the plane where the two arms C-21, C-22 are located. Fig.18A , Fig.18BIn the embodiment, the excitation unit C-23 is installed on both sides of the resonator C-2.

[0178] Fig.19 Shown to have in essence Fig.17 The driving unit is a driving unit with the same elements as the driving unit shown. This driving unit also has a pair of arms C-21 and C-22, but only the first arm C-21 contacts the passive element C-4 to drive the passive element C-4. As shown by the linear motion axis C-26, the movement of the driving unit is linear.

[0179] In the above-mentioned embodiment, the passive element C-4 is arranged between the arms C-21 and C-22, and the contact parts C-31 and C-32 at the ends of the arms face inwards. In other embodiments, although not shown in the figure, the arms C-21 and C-22 have an outward shape in which the contact parts C-31 and C-32 face away from each other. The passive element C-4 is arranged in a manner that contacts one or both of the contact parts C-31 and C-32 from the outside.

[0180] More embodiments of the drive unit that can apply the drive method suggested in this specification are disclosed in International Publication No. 2006 / 000118, U.S. Patent No. 7,429,812, and International Publication No. 2019 / 068708, which are incorporated herein by reference in their entirety.

[0181] Fig. 20 , along the same time axis t, three drive signals D1 , D2 , and D3 and the corresponding amplitudes A1 , A2 , and A3 of the vibration of the active element C- 1 are shown.

[0182] The first drive signal D1 is a rectangular signal with a period length Te, also called a "pulse period", and the excitation frequency fe is represented by fe=1 / Te. The maximum pulse width of the first drive signal D1 is Te / 2, that is, the pulse duty cycle dp is 50%.

[0183] Assuming that the pulse sequence of the first drive signal D1 begins at the start time t0, the corresponding first amplitude A1 of the vibration increases as the subsequent pulses of the excitation unit C-23 transfer mechanical energy to the active element C-1, especially as the mechanical energy is transferred to the resonator C-2 and its arms C-21, C-22. After a plurality of pulses, the vibration reaches a maximum and then becomes essentially constant in a steady state.

[0184] When the first amplitude A1 is lower than the activation threshold At, the arms C-21 and C-22 do not apply a driving force to the passive element C-4. When the first amplitude A1 is higher than the activation threshold At, the arms C-21 and C-22 apply a driving force to the passive element C-4, and the passive element C-4 is driven relative to the active element C-1. The same is true for the second amplitude A2 and the third amplitude A3.

[0185] The second drive signal D2 is a signal obtained by amplitude modulation of the first drive signal D1, and the amplitude is reduced relative to the maximum value (the amplitude of the first drive signal D1). The third drive signal D3 is a signal obtained by pulse width modulation of the first drive signal D1, and the pulse width or pulse duty cycle is reduced relative to the maximum value (the pulse width or pulse duty cycle of the first drive signal D1). Whether it is the second drive signal D2 or the third drive signal D3, the mechanical energy transmitted to the active element C-1 by each pulse is less than that of the first drive signal D1. Therefore, the trajectory of the second amplitude A2 and the third amplitude A3 rises more slowly than the first amplitude A1, and is flat at a lower fixed value or steady-state value. The time required to exceed the activation threshold At is longer than that of the first drive signal D1.

[0186] The amplitude of the vibration of the active element C-1 corresponds to the speed of movement of the passive element C-4 relative to the active element C-1. That is, the larger the amplitude of the vibration of the active element C-1, the faster the speed of movement of the passive element C-4 relative to the active element C-1. Therefore, by controlling the energy given to the active element C-1 per pulse, the movement speed of the drive unit can be controlled. The energy given to the active element C-1 per pulse corresponds to the shape of the pulse, and the shape is controlled by different types of modulation. As types of modulation, for example, pulse amplitude modulation and / or pulse width modulation are known.

[0187] If the energy transmitted to the active element C-1 per pulse is too small, the amplitude of the vibration of the active element C-1 may not exceed the activation threshold value At at all or may only exceed the activation threshold value At occasionally and uncertainly. Therefore, the action speed of the drive unit cannot be increased to a value higher than the speed threshold value Vt (refer to Fig. 22 ) is slow. Generally, the speed threshold Vt corresponds to the activation threshold At of the amplitude. The speed threshold Vt can be set within a range of 20% to 40% of the maximum speed in accordance with the physical and electrical characteristics of the drive unit.

[0188] Fig. 22 The above situation is shown by the relationship between the pulse width or pulse duty cycle dp and the generated speed v. If the pulse duty cycle dp is reduced from 50% of its maximum value, the action speed of the drive unit will decrease until it reaches the speed threshold Vt. If the pulse duty cycle dp is further reduced, the action speed of the drive unit will become zero.

[0189] In order to achieve a slower speed, the shape of the drive signal is maintained in such a way that the amplitude of the vibration of the active element in the stable state is greater than the activation threshold value At after adding a safety margin. Fig.21 As shown, the drive unit operates intermittently. In this figure, along the same time axis t, the fourth drive signal D4, the corresponding amplitude A4 of the active element C-1, and the displacement S of the passive element C-4 relative to the corresponding active element C-1 are shown. In addition, compared with Fig. 20 The timeline is a compressed timeline.

[0190] The fourth drive signal D4 includes pulses during the on period and does not include pulses during the off period. The sequence with pulses and the sequence without pulses are repeated periodically with a pulse block period Tb equal to the on time Ton + the off time Toff. The pulse block period is also called the excitation period. The repetition frequency fb=1 / Tb corresponding to the pulse block period is called the pulse block frequency. The relationship between the on time Ton and the pulse block period Tb, i.e., Ton / Tb, is called the pulse block duty cycle dpb.

[0191] In this way, pulses are applied to the drive unit only during the on period, and pulses are omitted or suppressed during the off period, so that the drive unit operates intermittently. During the on period that is long enough to make the amplitude of the vibration of the active element C-1 exceed the activation threshold value At, the passive element C-4 is driven relative to the active element C-1 after a corresponding delay. During the off period after the vibration is attenuated, the active element C-1 holds the passive element C-4 in a fixed position by prestressing. The displacement S increases through a series of steps and repetitions of the steady-state period. Fig.21 The average slope of the displacement S shown represents the average velocity of the passive element C-4 relative to the active element C-1.

[0192] Generally speaking, velocity refers to the relative motion between the active element C-1 and the passive element C-4 observed along a linear axis. In the case of a rotary drive unit, the angular velocity corresponds to the value obtained by dividing the velocity by the radius when the active element C-1 drives the passive element C-4.

[0193] In general applications, the pulse block period Tb may correspond to a pulse block frequency fb=1 / Tb of 5 kHz to 100 kHz, typically about 25 kHz. The frequency of the pulse itself is 50 kHz to 1000 kHz, typically about 500 kHz.

[0194] As a result, the maximum speed is about 80 mm / sec. The step length corresponding to each vibration cycle is in the range of 0.01 to 1 μm. The maximum force applied by the active element C-1 to the passive element C-4 is 100 mN (i.e., 0.1 N at most). The voltage applied to the excitation unit C-23 is about 3 V.

[0195] When the position of the drive unit needs to be obtained regardless of the speed, the controller C-90 corrects the position change within one pulse cycle, that is, the position step size.

[0196] For example, the shape of the driving pulse is modified to reduce the energy transmitted by each pulse so as to reduce the amplitude of the mechanical vibration driving the passive element C-4, thereby making the correction.

[0197] Alternatively, the excitation frequency is corrected to reduce the mechanical vibration to reduce the transfer of energy to the amplitude, and / or the direction of the mechanical vibration is changed, that is, the contribution to the driving force acting on the direction of motion of the passive element C-4 is changed, thereby making a correction.

[0198] Fig.23 The relationship between the excitation frequency f and the generated speed v is shown. At the first frequency f1, the resonator C-2 is in the first action mode or the first vibration mode, driving the passive element C-4 at the maximum speed in the first direction. At the second frequency f2, the resonator C-2 is in the second action mode, driving the passive element C-4 at the maximum speed in the second direction opposite to the first direction. In the case where there is a slight deviation before and after f1 or f2, respectively, corresponding to the misalignment of the excitation frequency of the active element C-1 in each vibration mode with respect to the natural frequency, the respective speeds are reduced.

[0199] In the above examples, the description is made in connection with a driving signal having a rectangular pulse. However, the same principle can be applied to pulses of different shapes, especially in terms of modulation of amplitude and pulse width and omission of pulses. For example, the principle can also be applied to pulses of sinusoidal, triangular, trapezoidal, or sawtooth shapes, or pulses of any shape.

[0200] The optimal excitation frequencies f1 and f2 for movement in opposite directions, as well as the excitation frequencies for different modes and directions, generally depend on the mechanical and electrical characteristics of the drive unit, especially the resonator C-2 and the excitation unit C-23. These characteristics change over time due to wear and parameter changes, corresponding to environmental conditions such as temperature and humidity, and corresponding to the orientation of the drive unit relative to the direction of gravity. Correspondingly, the optimal value of the excitation frequency also changes. In order to determine the optimal value, the drive unit can be operated at different frequencies, the response of the target can be measured, and the frequency at which the target response is optimal can be determined.

[0201] Fig.24 This is a flowchart showing the operation method of the drive unit of the embodiment. This process is executed by the controller C-90.

[0202] In the initialization step C-80, the method starts. In the measurement step C-81, the actual position of the drive unit, that is, the relative position between the active element C-1 and the passive element C-4, is determined. This position can be a rotational position or a translational position.

[0203] In the difference calculation step C-82, the difference d between the actual position and the set position is calculated. The difference d is represented by the position error signal. Depending on the value of the difference d, the method branches into different drive modes. According to different thresholds d1 < d2 < d3 and the absolute value abs(d) of the difference d, the drive unit is driven by drive signals with different parameters.

[0204] When abs(d) > d3 (in the determination step C-83, it is "y"), it is driven in the high-speed drive mode C-84. When d2 < abs(d) < d3 (in the determination step C-83, it is "n" and in the determination step C-85, it is "y"), it is driven in the medium-speed drive mode C-86. When d1 < abs(d) < d2 (in the determination step C-85, it is "n" and in the determination step C-87, it is "y"), it is driven in the low-speed drive mode C-88. In any of the above cases, the excitation frequency of the drive signal in the above example, that is, whether to use f1 or f2, is selected according to the direction in which the position should be corrected, that is, the sign of the difference d.

[0205] When abs(d) < d1 (in the determination step C-87, it is "n"), the drive unit is not driven. At this time, in the braking mode C-89, the passive element C-4 is held on the active element C-1 by prestress.

[0206] Then, by continuing the measurement step C-81, this process is repeated.

[0207] The values of the position error thresholds d1 to d3 are selected when designing or ordering the drive unit. These values can be set, for example, as d1 = 1μm, d2 = 5μm, and d3 = 10μm.

[0208] In the embodiment, in the high-speed drive mode C-84, the pulse duty ratio with respect to the maximum power of the drive signal is typically 50%, and the maximum pulse block duty ratio is typically 100%.

[0209] In the medium-speed drive mode C-86, for example, the pulse duty cycle of the drive signal is reduced compared to the pulse duty cycle of the high-speed drive mode C-84. Alternatively, the pulse block duty cycle of the drive signal is reduced compared to the pulse block duty cycle of the high-speed drive mode C-84.

[0210] In an embodiment, both the pulse duty cycle and the pulse block duty cycle are reduced. For example, the pulse duty cycle is 30% (not the maximum 50%), and the pulse block duty cycle is 50% (not the maximum 100%).

[0211] In the low-speed drive mode C-88, for example, the pulse duty cycle of the drive signal is reduced compared to the pulse duty cycle of the medium-speed drive mode C-86. Alternatively, the pulse block duty cycle of the drive signal is reduced compared to the pulse block duty cycle of the medium-speed drive mode C-86.

[0212] In an embodiment, both the pulse duty cycle and the pulse block duty cycle are reduced. For example, the pulse duty cycle is 20% (smaller than the pulse duty cycle in the medium speed drive mode C-86) and the pulse block duty cycle is 10% (smaller than the pulse block duty cycle in the medium speed drive mode C-86).

[0213] Thus, in the embodiment, the pulse duty ratio of the driving signal in the high-speed driving mode C-84 is 50%, and the pulse block duty ratio is 100%, the pulse duty ratio of the driving signal in the medium-speed driving mode C-86 is 30%, and the pulse block duty ratio is 50%. The pulse duty ratio of the driving signal in the low-speed driving mode C-88 is 20%, and the pulse block duty ratio is 10%.

[0214] In the embodiment, the case where the action of the drive unit is controlled using three drive modes with different speeds, namely, a high-speed drive mode C-84, a medium-speed drive mode C-86, and a low-speed drive mode C-88 is described. However, in another embodiment, the action of the drive unit may be controlled using only two drive modes with different speeds.

[0215] In addition, in the embodiment, the case of changing the pulse duty ratio and the pulse block duty ratio to control the movement speed of the drive unit is described, but it can also be that the pulse block frequency is changed according to the difference d equivalent to the position error to deal with it. For example, when the difference d is large, the pulse block frequency is set to 20 to 30kHz in the high-speed drive mode, and when the difference d is small, the pulse block frequency is changed to 10 to 15kHz in the medium-speed drive mode or the low-speed drive mode. The pulse block frequency is reduced in stages in the above manner, thereby slowing down the movement speed of the drive unit.

[0216] Specifically, when the pulse block frequency is set to 20kHz for a driving signal with a driving pulse of 700kHz, the number of pulses contained in a pulse block is 700kHz / 20kHz=35 pulses when the pulse block duty cycle is 100%, 35 / 2=18 pulses when the pulse block duty cycle is 50%, and 18 / 2=9 pulses when the pulse block duty cycle is 25%.

[0217] In contrast, when the pulse block frequency is set to 10kHz relative to a driving signal with a driving pulse of 700kHz, the number of pulses contained in a pulse block is 700kHz / 10kHz=70 pulses when the pulse block duty cycle is 100%, 70 / 2=35 pulses when the pulse block duty cycle is 50%, 35 / 2=18 pulses when the pulse block duty cycle is 25%, and 18 / 8=9 pulses when the pulse block duty cycle is 12.5%.

[0218] That is, if the pulse block frequency is reduced, the number of pulses included in one pulse block increases, so the variable range of the pulse duty ratio is widened. Therefore, the minimum value of the settable pulse block duty ratio can be reduced, making it easier to slow down the operation speed of the drive unit.

[0219] Thus, the method for operating the driving unit of the present invention is a method for operating the driving unit, which drives the passive element C-4 relative to the active element C-1, in which the active element C-1 has: a resonator C-2 and at least one exciting unit C-23 that excites the vibration of the resonator C-2. The resonator C-2 has at least one arm C-21 extending from the connecting portion C-20 of the resonator C-2. At least one arm C-21 has a contact portion C-31 at the outer end of the arm C-21, and the contact portion C-31 is movable by the vibration movement of the at least one arm C-21. The passive element C-4 is configured to move relative to the active element C-1 by being driven by the vibration movement. In addition, the passive element C-4 has a first contact area C-41, and the first contact area C-41 is configured in a manner of contacting the first contact portion C-31. The active element C-1 and the passive element C-4 are arranged so that when the active element C-1 is not excited, at least the first contact portion C-31 is pressed toward the first contact region C-41 due to the prestress.

[0220] Moreover, the operation method of the driving unit includes the following steps: driving the excitation unit C-23 by a driving signal and repeatedly omitting the driving pulse to generate a periodically repeated pulse block, wherein the driving signal is a periodic signal including driving pulses repeated at an excitation frequency, and the relationship between the on-time Ton of the pulse block and the pulse block period Tb, Ton / Tb, is used as the pulse block duty cycle; and correcting the driving signal in accordance with the position error signal.

[0221] In the step of correcting the drive signal, when the position error signal is within the first range, the shape of the drive pulse is corrected so that the shape of the drive pulse becomes the first drive pulse shape or the excitation frequency is corrected according to the first excitation frequency offset value, and the pulse block duty cycle is set to the first pulse block duty cycle value ( Fig.24 C-83, C-84), when the position error signal is within the second range, the shape of the drive pulse is corrected in such a way that the shape of the drive pulse becomes the second drive pulse shape or the excitation frequency is corrected according to the second excitation frequency offset value, and the pulse block duty cycle is set to the second pulse block duty cycle value ( Fig.24 C-85, C-86).

[0222] By repeatedly omitting the drive pulse, different pulse block duty cycle values ​​are provided, which corresponds to the correction of the duration Toff of the disconnection period during which the drive pulse is omitted according to the position error signal. As a result, the passive element C-4 can be driven quasi-continuously at a relatively slow average speed. As a result, the speed can be further reduced compared to the speed that can be achieved by simply reducing the shape of the drive pulse, and a given speed set point can be achieved. Such a speed can reduce the energy of the drive pulse to a level lower than the threshold required for the drive unit to reliably operate. At higher speeds, the speed can be controlled by the shape of the drive pulse.

[0223] By using different combinations of the drive pulse shape (or excitation frequency offset value) and pulse block duty cycle, the speed of the drive unit moving toward the set point (target position) is made consistent with the size of the position error signal. As a result, the position control of the drive unit can be performed at high speed and accurately.

[0224] Throughout this specification, when reference is made to the speed and position of the drive unit, it generally refers to the speed or position of the passive element C-4 relative to the active element C-1. The motion can be linear or rotational, or a combination thereof, depending on the mechanical structure and the excitation method.

[0225] In an embodiment, the driving unit is a piezoelectric driving unit, and the excitation unit C-23 is a piezoelectric element. In another embodiment, an electromagnetic actuator (voice coil, etc.), a magnetostrictive actuator, or an actuator with a shape memory alloy base can be used as the driving unit.

[0226] Typically, as described in Patent Document 1 or Patent Document 2, the movement of the contact portion C-31 is achieved by applying repeated pressing force to the passive element C-4 to move the passive element C-4, and the direction of the movement can be controlled by the excitation frequency of the excitation unit C-23.

[0227] Thus, the active element C-1 is capable of driving the passive element C-4 in response to the excitation frequency to move it in a first direction or in a second direction opposite to the first direction. In an embodiment, the movement performed by the passive element C-4 is a translational movement. In another embodiment, the movement is a rotational movement. In an embodiment, the resonator C-2 and its components are manufactured from a single piece of sheet material, in particular a thin sheet metal sheet.

[0228] In an embodiment, when the position error signal is within the third range, the shape of the drive pulse is corrected so that the shape of the drive pulse becomes a third drive pulse shape or the excitation frequency is corrected according to the third excitation frequency offset value, and the pulse block duty cycle is set to the third pulse block duty cycle value ( Fig.24 Steps C-87 to C-88).

[0229] In the embodiment, the shape of the driving pulse is corrected by at least one of correcting the amplitude of the driving pulse and correcting the pulse width of the driving pulse.

[0230] In the embodiment, in either case, in the modification of the shape of the drive pulse, the excitation frequency is kept constant and the energy delivered by each drive pulse is kept higher than a minimum pulse energy value, which is a value other than zero.

[0231] The energy transmitted by each drive pulse is kept higher than a minimum pulse energy value, which is a value other than zero, by keeping the pulse duty cycle of the drive pulse higher than a minimum pulse duty cycle value and keeping the amplitude of the drive pulse higher than a minimum amplitude value.

[0232] In an embodiment, the minimum pulse energy value is at least 5%, preferably at least 10% of the maximum energy of the pulse.

[0233] In an embodiment, the correction of the excitation frequency includes the following correction, that is, without changing the vibration mode, the excitation frequency is corrected only by an amount that reduces the matching between the excitation frequency and the natural frequency of the drive unit in the vibration mode. Thereby, the energy transfer to the mechanical vibration is reduced, and as a result, the amplitude is reduced.

[0234] In the embodiment, the driving pulse is repeatedly omitted, and during the OFF period when the driving pulse is omitted, the position of the passive element C- 4 relative to the active element C- 1 is maintained by the prestress.

[0235] In the embodiment, the duration Ton of the on period of applying the driving pulse when the driving pulse is repeatedly omitted is sufficient to realize the amplitude of the active element C-1 driving the passive element C-4 by the vibration of the active element C-1.

[0236] In the embodiment, the excitation frequency is within a range of 50 kHz to 1000 kHz, and the repetition of the drive pulse is omitted at a frequency of one tenth to one hundredth of the excitation frequency.

[0237] In an embodiment, the first range is higher than the second range, the energy of the driving pulse of the first driving pulse shape is greater than the energy of the driving pulse of the second driving pulse shape, and the first pulse block duty cycle value is greater than the second pulse block duty cycle value.

[0238] Therefore, when the value of the position error signal is high, that is, when the position error signal is within the first range, the driving unit moves faster than when the position error signal is within the second range. This is because, when the position error signal is within the first range, the energy of the driving pulse is greater and / or the pulse block duty cycle is greater than when the position error signal is within the second range.

[0239] In an embodiment, the driving pulse of the first driving pulse shape is a rectangular pulse with a pulse duty cycle of 50%, and the first pulse block duty cycle value is 100%, which corresponds to a rectangular pulse sequence with maximum power relative to a given peak voltage of the signal.

[0240] In an embodiment, the second range is higher than the third range, the energy of the driving pulse of the second driving pulse shape is greater than the energy of the driving pulse of the third driving pulse shape, and the second pulse block duty cycle value is greater than the third pulse block duty cycle value.

[0241] Therefore, when the value of the position error signal is small, that is, when the position error signal is within the third range, the operation speed of the drive unit is lower than when the position error signal is within the second range. This is because, when the position error signal is within the third range, the energy of the drive pulse is smaller and / or the pulse block duty cycle is smaller than when the position error signal is within the second range.

[0242] In an embodiment, the operation method of the drive unit includes: setting the frequency of the excitation frequency corresponding to the positive and negative signs of the position error signal. Thus, the direction of movement can be changed by selecting the excitation frequency, and the direction of movement can be set according to the direction in which the drive unit needs to move in order to reduce the position error.

[0243] In an embodiment, the driving unit is operated in a manner that the passive element C-4 is driven relative to the active element C-1, wherein the active element C-1 includes: a resonator C-2 and at least one excitation unit C-23 that excites the vibration of the resonator C-2, and the resonator C-2 includes at least two arms C-21 and C-22 extending from the connecting portion C-20 of the resonator C-2, and the arms C-21 and C-22 have contact portions C-31 and C-32 at the outer ends of the arms C-21 and C-22, respectively, and the contact portions C-31 and C-32 are movable by the vibration movement of each arm C-21 and C-22. The passive element C-4 is configured to be driven relative to the active element C-1 by these vibration movements, thereby moving. In addition, the passive element C-4 includes a first contact area C-41 and a second contact area C-42, and each contact area C-41 and C-42 is configured to contact each of the first contact portion C-31 and the second contact portion C-32. The active element C-1 and the passive element C-4 are configured so that, especially when the active element C-1 is not excited, the first contact portion C-31 and the second contact portion C-32 are pressed toward the first contact area C-41 and the second contact area C-42 respectively due to prestress.

[0244] In an embodiment, the second arm C-22 is configured to move in a vibration motion that is balanced with the vibration motion of the first arm C-21. That is, when the excitation unit C-23 is excited at a frequency that drives the passive element C-4 relative to the active element C-1, the first arm C-21 and the second arm C-22 vibrate in a motion that is balanced with each other.

[0245] Typically, a resonator C-2 of the type presented in this specification has a resonator axis corresponding to the symmetry axis of the geometric shape of the resonator C-2. In the case of a resonator C-2 of substantially planar shape, the resonator axis is located in its reference plane. Symmetry with respect to the resonator axis can be understood as symmetry corresponding to the general shape of the arms C-21, C-22, and there may be cases where the symmetry is not complete with respect to the subtle parts of the shape of the arms C-21, C-22.

[0246] Therefore, when at least two arms C-21, C-22 extend substantially symmetrically from the connection portion C-20, there may be differences in subtle parts of their shapes or contours. For example, when measured in the direction in which the arms C-21, C-22 extend, one arm (e.g., the first arm C-21) may be shorter than the other arm (e.g., the second arm C-22). For example, one arm may be shorter than the other arm by up to 10%, up to 20%, up to 30%, or up to 40%.

[0247] When the arms C-21 and C-22 are symmetrically arranged about the resonator axis or symmetry point, the movements of the arms C-21 and C-22 can be balanced. As a result, the vibration movement of the resonator C-2 can be essentially symmetrical about the resonator axis.

[0248] In an embodiment, the connecting portion C-20 is substantially rectangular in shape. Typically, the excitation unit C-23 is also substantially rectangular in shape. The sides of the rectangle corresponding to the rectangular approximation of the connecting portion C-20 can be aligned parallel to the sides of the rectangle corresponding to the rectangular approximation of the excitation unit C-23.

[0249] The resonator C-2 and its components are in one piece, that is, the components of the resonator C-2, such as the connection portion C-20, the first arm C-21 and the second arm C-22, the mounting area, and the optional bearing arm, are manufactured as a single piece with the resonator C-2. This can be done, for example, by punching or cutting the resonator C-2 from a thin sheet metal, or by casting, or by additional manufacturing steps.

[0250] In addition, in this embodiment, the controller C-90 is a controller configured to execute the above-mentioned action method of the drive unit. It is connected to the excitation unit C-23 of the drive unit and supplies power to the excitation unit C-23, reads the signal from the sensor 91 and determines the position of the drive unit.

[0251] Further embodiments of the controller C-90 are known from the dependent claims of the method claim. In addition, the features of the method claim can be combined with the features of the device claim, and vice versa.

[0252] 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 a scope not departing from the gist thereof.

[0253] 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 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 portable phone with a camera, a laptop computer, a tablet terminal, a portable game console, a web camera, and a vehicle-mounted device with a camera (for example, a rear monitoring device, a driving recorder device). In addition, transportation equipment includes, for example, a car.

[0254] Fig.25A , Fig.25B 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.25A This is the front view of the car V. Fig.25B FIG. 1 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.25A , Fig.25B As shown, the vehicle-mounted camera module VC is mounted on a windshield facing forward, or mounted on a tailgate facing backward. The vehicle-mounted camera module VC is used for rear monitoring, driving recorder, collision avoidance control, automatic driving control, and the like.

[0255] In the embodiment, the first arm portion 141b of the AF driving unit 14 is brought into contact with the AF urging member 112, 512 constituting the AF movable portion 11, 51, but the first arm portion 141b of the AF driving unit 14 may be brought into direct contact with the lens holder 111, 511. However, compared with contacting with the lens holder 111, 511 which is a resin molded part, contacting with the AF urging member 112, 512 which is a metal molded part can efficiently transmit the driving force and improve the durability.

[0256] Alternatively, a biasing member for biasing the lens holder 111 or 511 toward the first stage 12 and a member against which the first arm 141 b of the AF drive unit 14 abuts may be separately provided.

[0257] In the embodiment, two AF drive units 14A and 14B are provided, but the number of AF drive units 14 may be one or three or more as long as a drive force capable of moving the AF movable unit 11 or 51 in the Z direction can be exerted.

[0258] Furthermore, the present invention can be applied not only to the case of automatic focusing but also to the case of moving a movable portion in the optical axis direction, such as zooming.

[0259] Furthermore, the supporting structure of the AF movable part 51 using the AF force applying component 512 in the second embodiment is not limited to being applied to the case where the driving source is composed of an ultrasonic motor as in the AF driving part 14, but can also be applied to a lens driving device having a driving source other than an ultrasonic motor (for example, a voice coil motor (VCM)).

[0260] 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 of the present application rather than the above description, and includes all modifications within the meaning and scope equivalent to the claims.

[0261] The disclosure contents of the specification, drawings and abstract included in Japanese Patent Application No. 2019-225710 filed on December 13, 2019 are incorporated herein by reference in their entirety.

[0262] Description of Reference Numerals

[0263] 1. 1A lens drive device

[0264] 10. 10A OIS movable part (second movable part)

[0265] 11. 51AF movable part (first movable part)

[0266] 111, 511 lens holder

[0267] Force-applying parts for 112 and 512AF

[0268] 12 first stage (first fixed part)

[0269] 13 Second Station

[0270] 14AF drive unit (Z direction drive unit)

[0271] 141 AF resonance section

[0272] 142 AF Piezoelectric Element

[0273] 143 AF Electrode

[0274] 15AF support part (first support part)

[0275] 20OIS fixing part (second fixing part)

[0276] 21 Base

[0277] 30OIS drive unit (XY direction drive unit)

[0278] 31 OIS resonance part

[0279] 32 OIS piezoelectric element

[0280] 33 OIS electrode

[0281] 34 OIS power transmission unit

[0282] 40OIS support part (second support part)

[0283] 50 OIS force applying component

[0284] A Camera Module

[0285] M smartphone (camera-equipped device)

Claims

1. A driving device, characterized in that: have: an AF unit including a first fixed portion, a first movable portion arranged to be spaced apart from the first fixed portion, a Z-direction driving portion, and a first supporting portion supporting the first movable portion relative to the first fixed portion, wherein the Z-direction driving portion is constituted by an ultrasonic motor having a piezoelectric element and a resonance portion and converting a vibration motion into a linear motion, and is an actuator for moving the first movable portion in the Z direction; as well as The AF urging member functions as a leaf spring by coming into contact with the Z-direction driving portion under pressure, and urges the first movable portion in one direction within a plane orthogonal to the Z-direction relative to the first fixed portion via the first supporting portion.

2. The driving device according to claim 1, wherein: The first supporting part is a ball.

3. The driving device according to claim 1 or 2, wherein: The AF urging member is a metal molded part.

4. A camera module, characterized in that: have: The driving device according to any one of claims 1 to 3; a lens portion included in the first movable portion; and The imaging unit captures the image of the object formed by the lens unit.

5. A camera-mounted device, which is information equipment or transportation equipment, wherein the camera-mounted device is characterized by comprising: The camera module of claim 4; and The image processing unit processes the image information obtained by the camera module.

Images