Image sensor driving device

Abstract

To provide an image sensor drive device capable of reducing the size of an actuator.SOLUTION: An image shake correction unit 1 includes: a front fixation holding member 32 having a fixing surface; and a driving magnet 27c that is fixed to the fixing surface of the front fixation holding member 32 and is used for driving an image sensor 12. The Side surface at the periphery facing the driving magnet 27c on the front fixation holding member 32 is placed so as to be almost hidden by the driving magnet 27c viewing the front fixation holding member 32 from a direction perpendicular to the imaging surface of the image sensor 12.SELECTED DRAWING: Figure 7A

Description

[Technical Field]

[0001] The present disclosure relates to an imaging element driving device. [Background technology]

[0002] BACKGROUND ART Conventionally, imaging devices having a mechanism for correcting blurring of an optical image during imaging (hereinafter referred to as an "image blur correction mechanism") have been widely used in order to obtain clear captured images.

[0003] Such image stabilization mechanisms include optical image stabilization mechanisms and image sensor-driven image stabilization mechanisms. Optical image stabilization mechanisms drive part or all of the optical lens for correction in a plane perpendicular to the optical axis or in a direction tilted relative to the optical axis (see, for example, Patent Document 1). On the other hand, image sensor-driven image stabilization mechanisms drive the image sensor for correction in a plane perpendicular to the optical axis (see, for example, Patent Document 2).

[0004] Also, there is known an imaging device that can obtain a high-definition image from a plurality of pieces of image data by driving an imaging element in minimum pixel units in a plane perpendicular to the optical axis (see, for example, Patent Document 3).

[0005] Furthermore, there is known an imaging device that can obtain a higher resolution image from a plurality of pieces of image data by driving an imaging element at a pitch shorter than the minimum pixel unit in a plane perpendicular to the optical axis (see, for example, Patent Document 4). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-83753 [Patent Document 2] Japanese Patent Application Laid-Open No. 2012-48215 [Patent Document 3] Japanese Patent Application Laid-Open No. 2010-73035 [Patent Document 4] Japanese Patent Application Laid-Open No. 2011-227578 Summary of the Invention [Problem to be solved by the invention]

[0007] The present disclosure provides an imaging element driving device that can achieve a miniaturized actuator. [Means for solving the problem]

[0008] The image sensor driving device of the present disclosure is an image sensor driving device for driving an image sensor, and comprises a yoke having a fixed surface, and a magnet fixed to the fixed surface of the yoke and used to drive the image sensor, and the side surface of the peripheral portion of the yoke facing the magnet is positioned so that it is largely hidden by the magnet when the yoke is viewed from a direction perpendicular to the imaging surface of the image sensor.

[0009] In addition, the image sensor driving device in the present disclosure is an image sensor driving device for driving an image sensor, and includes a yoke having a fixed surface, and a magnet fixed to the fixed surface of the yoke and used to drive the image sensor, and the inner periphery of the yoke is formed so that the image sensor is exposed when the yoke and image sensor are viewed from the optical axis direction, and the side of the inner periphery of the yoke that faces the magnet is positioned so that it is largely hidden by the magnet when the yoke is viewed from the optical axis direction.

[0010] In addition, the image sensor driving device in the present disclosure is an image sensor driving device for driving an image sensor, and includes a yoke having a fixed surface, and a magnet fixed to the fixed surface of the yoke and used to drive the image sensor, and when the yoke and image sensor are viewed from the optical axis direction, the inner circumference of the yoke is formed so that the image sensor is exposed, and when the yoke and magnet are viewed from the optical axis direction, the magnet on the inner circumference side of the yoke is fixed to the yoke so that a portion of the inner circumference of the yoke is generally hidden by the magnet on the inner circumference side of the yoke.

[0011] In addition, the image sensor driving device of the present disclosure is an image sensor driving device for driving an image sensor, and includes a yoke having a fixed surface, and a magnet used to drive the image sensor, the magnet being arranged along the peripheral portion of the yoke and fixed to the fixed surface of the yoke, and the side of the magnet that is approximately perpendicular to the fixed surface is exposed to the outside along the peripheral portion of the yoke.

[0012] In addition, the image sensor driving device of the present disclosure is an image sensor driving device for driving an image sensor, and includes a yoke having a fixed surface, and a magnet fixed to the fixed surface of the yoke and used to drive the image sensor, and the side surface of the peripheral portion of the yoke is positioned so that it is largely hidden by the magnet when the yoke is viewed from a direction perpendicular to the imaging surface of the image sensor.

[0013] Furthermore, an image sensor driving device according to the present disclosure is an image sensor driving device for driving an image sensor, and includes a fixed frame, a movable frame for holding the image sensor, the movable frame facing the fixed frame in the optical axis direction and displaceable relative to the fixed frame in a plane perpendicular to the optical axis direction, a magnetic body provided on one of the fixed frame and the movable frame, and at least one magnet provided on the other of the fixed frame and the movable frame facing the magnetic body in the optical axis direction, the at least one magnet having an S1 magnetized portion magnetized to an S pole on the side facing the magnetic body, The magnetic body has an N2 magnetized portion that is arranged adjacent to the S1 magnetized portion in a first direction and is magnetized to an N pole, an S3 magnetized portion that is arranged adjacent to the N2 magnetized portion in a second direction that intersects with the first direction and is magnetized to an S pole, and an N4 magnetized portion that is arranged adjacent to the S3 magnetized portion in a third direction that intersects with the second direction and is adjacent to the S1 magnetized portion and is magnetized to an N pole, and when viewed from the optical axis direction, the magnetic body overlaps with at least a portion of the S1 magnetized portion, the N2 magnetized portion, the S3 magnetized portion, and the N4 magnetized portion.

[0014] In addition, the manufacturing method of an image sensor driving device in the present disclosure is a manufacturing method of an image sensor driving device that includes a yoke and a magnet fixed to the yoke, and includes the steps of (a) placing the magnet on a base jig, (b) attracting the magnet toward the base jig using an attraction jig, (c) applying adhesive to one of the magnet and the yoke, and (d) fixing the magnet to the yoke via the adhesive by placing the yoke on the base jig.

[0015] In addition, the imaging element driving device of the present disclosure is an imaging element driving device for driving an imaging element, and includes a yoke having a fixed surface, and a magnet used to drive the imaging element, the magnet being arranged along the peripheral portion of the yoke and fixed to the fixed surface of the yoke with an adhesive, and the entire back surface of the magnet is in contact with the fixed surface of the yoke via the adhesive. [Effects of the Invention]

[0016] According to the imaging element driving device of the present disclosure, it is possible to achieve a miniaturized actuator. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a perspective view of a digital camera according to an embodiment. [Figure 2] FIG. 2 is a rear view of the digital camera according to the embodiment. [Figure 3] FIG. 3 is a front view of the image shake correction device according to the embodiment. [Figure 4] FIG. 4 is an exploded perspective view of the image shake correction device according to the embodiment. [Figure 5] FIG. 5 is a rear view of the movable frame according to the embodiment. [Figure 6] FIG. 6 is a cross-sectional view of the movable frame according to the embodiment taken along line VI-VI in FIG. [Figure 7A] FIG. 7A is a perspective view of the rear side of the front surface fixing and holding member according to the embodiment. [Figure 7B]7B is a cross-sectional view of the front fixing holding member according to the embodiment taken along line VII-VII in FIG. 7A. [Figure 8] FIG. 8 is a perspective view for explaining a method of adhering the drive magnet to the front fixing and holding member according to the embodiment. [Figure 9] FIG. 9 is a front view of the rear surface fixing and holding member according to the embodiment. [Figure 10A] FIG. 10A is a diagram showing the magnetization of the sensor magnet according to the embodiment. [Figure 10B] FIG. 10B is a diagram showing the magnetization of the sensor magnets according to the first and second comparative examples. [Figure 11] FIG. 11 is a graph showing the relationship between the diagonal position of the suction plate and the suction force acting on the suction plate in the optical axis direction in Experiment 1. [Figure 12] FIG. 12 is a graph showing the relationship between the diagonal position of the attraction plate and the torque acting on the attraction plate in Experiment 1. [Figure 13] FIG. 13 is a diagram showing the torque measurement conditions in Experiment 1. [Figure 14] FIG. 14 is a graph showing the relationship between the diagonal position of the suction plate and the suction force acting on the suction plate in the optical axis direction in Experiment 2. [Figure 15] FIG. 15 is a graph showing the relationship between the diagonal position of the attraction plate and the torque acting on the attraction plate in Experiment 2. [Figure 16] FIG. 16 is a diagram showing the torque measurement conditions in Experiment 2. DETAILED DESCRIPTION OF THE INVENTION

[0018] (Findings that formed the basis of this disclosure) The present inventors have found that the techniques described in the "Background Art" section have the following problems.

[0019] An imaging device (e.g., a digital camera) with an image sensor-driven image shake correction mechanism includes an image sensor and an image sensor drive device for driving the image sensor. The image sensor drive device includes a fixed frame, a movable frame that is displaceable two-dimensionally relative to the fixed frame within a plane perpendicular to the optical axis, and an actuator for displacing the movable frame relative to the fixed frame. The image sensor is attached to the movable frame and is displaceable together with the movable frame relative to the fixed frame. The imaging device calculates the direction and amount of displacement of the image sensor within the plane from the output of an angular velocity sensor provided in the imaging device body, and corrects blur of the subject image formed by the photographing lens on the image sensor based on the calculated direction and amount of displacement.

[0020] Here, the displacement amount of the imaging element is the amount of movement of the imaging element in a plane perpendicular to the optical axis from a reference position (a position when the imaging element is not displaced) in the same plane.

[0021] The movable frame is supported displaceably on the fixed frame via a rolling bearing consisting of at least three ball members. Therefore, a force (hereinafter referred to as "attractive force") is required to urge the movable frame toward the fixed frame via the ball members. Methods for generating this attractive force include a tension spring method and a magnetic attraction method.

[0022] With the tension spring method, the spring force increases in accordance with the amount of displacement of the imaging element, and not only does the force of attraction of the movable frame toward the fixed frame increase, but also the force in the opposite direction to the displacement of the imaging element. Furthermore, with the tension spring method, static contact between the movable frame and the fixed frame cannot be avoided, and friction between the movable frame and the fixed frame due to displacement of the movable frame adversely affects actuator control.

[0023] On the other hand, in the magnetic attraction method, unlike the tension spring method, the attractive force decreases according to the amount of displacement of the image sensor, and a force similar to that of a tension spring is generated in the opposite direction to the displacement direction of the image sensor. Therefore, in both methods, there is a problem that the control of the actuator becomes very complicated.

[0024] The actuator also has a yoke and multiple magnets fixed to the yoke. Conventionally, the following two methods have been used to fix the magnets. In the first method, holes are drilled in the yoke beforehand, and adhesive is poured through the holes into the gap between the yoke and the magnets in contact with the yoke. In the second method, the magnets are temporarily placed on the yoke and positioned relative to the yoke, and then adhesive is poured into the gap between the magnets and the yoke from the corners of the magnets.

[0025] However, the first method requires drilling holes in the yoke, which reduces the volume of the yoke and reduces the magnetic force on the coil, while the second method requires space in the yoke to allow adhesive to flow into the corners of the magnet, which increases the size of the actuator.

[0026] The present disclosure is based on such knowledge, and as a result of intensive research by the inventors, they have come up with an idea for an image sensor driving device that can stably drive an image sensor, a method for manufacturing an image sensor driving device, and an image sensor.

[0027] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. However, more detailed explanation than necessary may be omitted. For example, detailed explanation of well-known matters or redundant explanation of substantially the same configuration may be omitted. This is to avoid unnecessary redundancy in the following explanation and to facilitate understanding by those skilled in the art.

[0028] The inventors provide the accompanying drawings and the following description to enable those skilled in the art to fully understand the present disclosure, and do not intend for them to limit the subject matter described in the claims.

[0029] In the following embodiments, a digital camera will be described as an example of an "imaging device." In the following description, "front (positive direction of the Z axis)," "rear (negative direction of the Z axis)," "up (positive direction of the Y axis)," "down (negative direction of the Y axis)," "right (negative direction of the X axis)," and "left (positive direction of the X axis)" are terms based on an imaging device in a landscape orientation facing a subject, with the subject side being referred to as "front" and the opposite side of the subject (i.e., the photographer side) being referred to as "rear." Furthermore, the direction of rotation around the Y axis (up-down direction) is referred to as the "pitch direction," the direction of rotation around the X axis (left-right direction) as the "yaw direction," and the direction of rotation around the Z axis as the "roll direction."

[0030] (Embodiment) [1. Configuration] [1-1. Overview of a digital camera] First, the schematic configuration of a digital camera 100 (an example of an imaging device) according to the first embodiment will be described with reference to Fig. 1 and Fig. 2. Fig. 1 is a perspective view of the digital camera 100 according to the embodiment. Fig. 2 is a rear view of the digital camera 100 according to the embodiment.

[0031] 1 and 2, the digital camera 100 includes a camera body 101 (an example of an imaging device) and a lens unit 200 (an example of an imaging device). The digital camera 100 is, for example, an interchangeable lens type digital camera.

[0032] As shown in FIGS. 1 and 2, the camera body 101 includes a housing 10, a body mount 20, a shutter button 30, a hot shoe 40, a flash unit 50, an electronic viewfinder 60, and a display device 70.

[0033] The housing 10 houses the image stabilization device 1 (see FIG. 3) and other components. The housing 10 has a front surface S1, a top surface S2, a rear surface S3, and a bottom surface S4. A body mount 20 is provided on the front surface S1 of the housing 10. A lens unit 200 can be attached to the body mount 20 by bayonet coupling or the like. The body mount 20 has an opening 20a centered on the optical axis AX of the lens unit 200. The optical axis AX is an axis parallel to the Z axis. Incident light from the lens unit 200 is guided into the housing 10 through the opening 20a. A shutter button 30 is provided on the top surface S2 of the housing 10. The shutter button 30 accepts an operation by the photographer (user) to open and close the shutter.

[0034] A hot shoe 40 is provided on the top surface S2 of the housing 10. A general-purpose external component (for example, a flash device) can be attached to the hot shoe 40. A flash unit 50 is provided on the top surface S2 of the housing 10. The flash unit 50 can be stored inside the housing 10. Note that Figures 1 and 2 show the flash unit 50 pulled out from the housing 10. An electronic viewfinder 60 is provided on the rear surface S3 of the housing 10. The electronic viewfinder 60 displays an image of the shooting range. The photographer can observe the image displayed on the electronic viewfinder 60. A display device 70 is provided on the rear surface S3 of the housing 10. The display device 70 displays an image of the shooting range, an operation menu, etc. The display device 70 can be, for example, a liquid crystal display, an organic EL (Electro-Luminescence) display, an inorganic EL display, etc.

[0035] Furthermore, the camera body 101 includes a shutter unit (not shown), an image stabilization device 1 (an example of an image sensor driving device) (see FIG. 3), an image sensor 12 (see FIG. 6), a circuit board 13 (see FIG. 5), and a control circuit board (not shown), which are arranged inside the housing 10. The image sensor 12 is configured, for example, by a CMOS (Complementary Metal Oxide Semiconductor) image sensor, a CCD (Charge-Coupled Device) image sensor, or the like.

[0036] In the present embodiment, the digital camera 100 is an interchangeable lens type digital camera, but the present invention is not limited to this. The digital camera 100 may be, for example, a digital camera with an integrated lens, or a single-lens reflex digital camera.

[0037] 1, lens unit 200 is an interchangeable lens unit. Lens unit 200 has a lens mount 201 attached to a body mount 20 of camera body 101, a focus ring 202 which is an operation unit for driving the focus lens, and a zoom ring 203 which is an operation unit for driving the zoom lens. Although not shown, lens unit 200 also internally includes a lens controller, an optical system including a focus lens and a zoom lens, a focus lens driver, a zoom lens driver, an aperture, an aperture driver, a DRAM (Dynamic Random Access Memory), a flash memory, and the like.

[0038] Light from a subject enters the camera body 101 via an optical system inside the lens unit 200 and is received by the light-receiving surface of the image sensor 12. The optical image received by the image sensor 12 is converted into an electrical signal, i.e., image data. The image data undergoes predetermined processing (e.g., AD (Analog / Digital) conversion) by the circuit board 13, and is then displayed on the display device 70 by the control circuit board. The circuit board 13 is equipped with a controller that executes predetermined programs stored in nonvolatile memory such as a ROM (Read Only Memory), and a RAM that temporarily stores data during control operations and image processing operations. The controller may be configured, for example, with a CPU (Central Processing Unit), an MPU (Micro Processing Unit), a DSP (Digital Signal Processing), an FPGA (Field Programmable Gate Array), or an ASIC (Application Specific Integrated Circuit).

[0039] [1-2. Schematic configuration of image stabilization device] Next, the schematic configuration of the image blur correction device 1 according to the embodiment will be described with reference to FIGS. 3 to 7B.

[0040] FIG. 3 is a front view of an image shake correction device 1 according to an embodiment. FIG. 4 is an exploded perspective view of an image shake correction device 1 according to an embodiment. FIG. 5 is a rear view of a movable frame 11 according to an embodiment. FIG. 6 is a cross-sectional view of the movable frame 11 according to the embodiment, taken along line VI-VI in FIG. 5. FIG. 7A is a perspective view of the rear side of a front surface fixing and holding member 32 according to an embodiment. FIG. 7B is a cross-sectional view of the front surface fixing and holding member 32 according to an embodiment, taken along line VII-VII in FIG. 7A.

[0041] 3 to 7A, the image blur correction device 1 is a drive mechanism for driving the image sensor 12. As shown in FIGS. 3 to 7A, the image blur correction device 1 includes a movable frame 11, a circuit board 13, ball holding portions 110a, 110b, and 110c, drive coils 15, 16, and 17, drive magnets 25a, 25b, 25c, 25d, 26b, 26d, 27a, 27b, 27c, and 27d (examples of magnets), magnetic displacement detection sensors 14a, 14b, and 14c (examples of displacement detection portions), sensor magnets 22a, 22b, 23a, 23b, 24a, and 24b (examples of magnets), an attraction plate 19 (an example of a magnetic body), a rear surface fixed holding member 21 (an example of a fixed frame and a yoke), and a front surface fixed holding member 32 (an example of a yoke).

[0042] As shown in Fig. 5, the movable frame 11 is equipped with a circuit board 13, ball holders 110a, 110b, and 110c, drive coils 15, 16, and 17, magnetic displacement detection sensors 14a, 14b, and 14c, and an attraction plate 19. As shown in Fig. 4, drive magnets 25a, 25b, 26b, 27a, and 27b and sensor magnets 22a, 22b, 23a, 23b, 24a, and 24b are attached to the rear fixed holding member 21 with an adhesive. As shown in Fig. 7A, drive magnets 25c, 25d, 26d, 27c, and 27d are attached to the front fixed holding member 32 with an adhesive 28 (see Fig. 7B).

[0043] 7B, the entire back surface of each of the drive magnets 27c and 27d is in contact with the fixed surface (the surface facing the movable frame 11) of the front fixed holding member 32 via the adhesive 28. Although not shown, the entire back surfaces of the other drive magnets 25c, 25d, and 26d are also in contact with the fixed surface of the front fixed holding member 32 via the adhesive 28. Furthermore, although not shown, the entire back surfaces of each of the drive magnets 25a, 25b, 26b, 27a, and 27b and the sensor magnets 22a, 22b, 23a, 23b, 24a, and 24b are in contact with the fixed surface of the rear fixed holding member 21 (the surface facing the movable frame 11) via the adhesive.

[0044] As shown in FIGS. 3 to 6, the movable frame 11 is configured to hold the imaging element 12 and is disposed opposite the rear fixed holding member 21 and the front fixed holding member 32. The imaging element 12 is fixed to the movable frame 11 with an adhesive or the like. The movable frame 11 holds the imaging element 12 so that it can be displaced in a plane perpendicular to the optical axis AX. The circuit board 13 is electrically connected to the imaging element 12 and converts the electrical signal from the imaging element 12 from an analog signal to a digital signal. The ball holding portions 110a, 110b, and 110c hold ball members 31a, 31b, and 31c (an example of a support member) (see FIG. 4) that connect the movable frame 11 and the rear fixed holding member 21. The ball members 31a, 31b, and 31c support the movable frame 11 so that it can be displaced relative to the rear fixed holding member 21. The ball holding portions 110a, 110b, and 110c will be described in detail below. The movement of the movable frame 11 relative to the rear fixing and holding member 21 is restricted by a movement restricting mechanism (described later).

[0045] As shown in FIG. 5, the three drive coils 15, 16, and 17 are fixed to the movable frame 11 with an adhesive. The terminals of the drive coils 15, 16, and 17 are electrically connected to the circuit board 13 via FPCs (Flexible Printed Circuits) and receive power from the circuit board 13. The drive coil 15 is disposed to face two pairs of drive magnets 25a, 25c and 25b, 25d in the direction of the optical axis AX. The drive coil 16 is disposed to face two pairs of drive magnets 26b, 26d and 27a, 27c in the direction of the optical axis AX. The drive coil 17 is disposed to face two pairs of drive magnets 27a, 27c and 27b, 27d in the direction of the optical axis AX. These drive coils 15 to 17 and drive magnets 25a to 27d constitute an actuator that drives the image sensor 12.

[0046] In this embodiment, each of the drive magnets 25a, 25d, 26d, 27a, and 27d is magnetized to an N pole on the side facing the drive coils 15, 16, and 17. Each of the drive magnets 25b, 25c, 26b, 27b, and 27c is magnetized to an S pole on the side facing the drive coils 15, 16, and 17. Here, the pair of drive magnets 27a and 27c are Although they are arranged (shared) to face both drive coil 16 and drive coil 17, four magnets may be used instead of the pair of drive magnets 27a, 27c. That is, two of the four magnets may be arranged to face drive coil 16, and the remaining two magnets may be arranged to face drive coil 17.

[0047] As shown in FIG. 5, the three magnetic displacement detection sensors 14a, 14b, and 14c are disposed on the circuit board 13. Each of the magnetic displacement detection sensors 14a, 14b, and 14c is configured, for example, by a Hall element. As shown in FIG. 9, which will be described later, sensor magnets 22a and 22b are disposed on the rear fixed holding member 21 facing the magnetic displacement detection sensors 14a, 14b, and 14c, facing the magnetic displacement detection sensor 14a in the direction of the optical axis AX, sensor magnets 23a and 23b are disposed on the rear fixed holding member 21 facing the magnetic displacement detection sensors 14a, 14b, and 14c, facing the magnetic displacement detection sensor 14b in the direction of the optical axis AX, and sensor magnets 24a and 24b are disposed on the rear fixed holding member 21, facing the magnetic displacement detection sensors 14a, 14b, and 14c. The magnetic displacement detection sensors 14a, 14b, and 14c and the sensor magnets 22a, 22b, 23a, 23b, 24a, and 24b constitute a displacement detection mechanism that detects the displacement of the image sensor 12 (movable frame 11) relative to the rear fixed holding member 21. The displacement detection mechanism will be described later.

[0048] 4 and 9 described later, each of the sensor magnets 22a, 23a, and 24a is magnetized to the south pole on the side facing the movable frame 11 (attraction plate 19 described later) and is magnetized to the north pole on the side opposite the attraction plate 19. Furthermore, each of the sensor magnets 22b, 23b, and 24b is magnetized to the north pole on the side facing the movable frame 11 (attraction plate 19) and is magnetized to the south pole on the side opposite the attraction plate 19.

[0049] Here, sensor magnets 22a, 22b, 23a, and 23b are examples of a first magnet, a second magnet, a third magnet, and a fourth magnet, respectively. The south pole side of sensor magnet 22a is an example of an S1 magnetized portion, and the north pole side is an example of an N1 magnetized portion. Furthermore, the north pole side of sensor magnet 22b is an example of an N2 magnetized portion, and the south pole side is an example of an S2 magnetized portion. Furthermore, the south pole side of sensor magnet 23a is an example of an S3 magnetized portion, and the north pole side is an example of an N3 magnetized portion. Furthermore, the north pole side of sensor magnet 23b is an example of an N4 magnetized portion, and the south pole side is an example of an S4 magnetized portion.

[0050] If the complexity of the magnetization is acceptable, one magnet may be formed with S1-S4 magnetized portions and N1-N4 magnetized portions, or one magnet may be formed with S1, S2 magnetized portions and N1, N2 magnetized portions, and another magnet may be formed with S3, S4 magnetized portions and N3, N4 magnetized portions.

[0051] The attraction plate 19 is made of a magnetic material such as a metal plate. As shown in FIGS. 4 to 6, the attraction plate 19 is disposed on the movable frame 11 so as to face the sensor magnets 22a, 22b, 23a, and 23b. The attraction plate 19 attracts the movable frame 11 toward the rear fixed holding member 21 by utilizing the magnetic forces of the sensor magnets 22a, 22b, 23a, and 23b. This biases the ball members 31a, 31b, and 31c held by the ball holding portions 110a, 110b, and 110c, respectively, described below, toward the rear fixed holding member 21, thereby pressing them against the movable frame 11. The attraction plate 19 and the sensor magnets 22a, 22b, 23a, and 23b constitute a magnetic attraction mechanism. The magnetic attraction mechanism will be described later.

[0052] The rear surface fixing and holding member 21 is fixed to a support frame (not shown) inside the camera body 101.

[0053] [1-3. Ball holding area] Next, the ball holding portions 110a, 110b, and 110c will be described with reference to FIGS.

[0054] As shown in Fig. 5, the ball holding portions 110a, 110b, and 110c are formed in a substantially rectangular shape in a plan view and are arranged at three locations on the movable frame 11. As shown in Fig. 5 and Fig. 6, the ball holding portions 110a, 110b, and 110c have standing walls 110d, 110e, and 110f that surround the ball members 31a, 31b, and 31c, respectively. Note that the standing walls 110d, 110e, and 110f are surfaces that form the ball holding portions 110a, 110b, and 110c and are substantially parallel to the optical axis AX.

[0055] The ball holding portions 110a, 110b, and 110c each have a surface (hereinafter referred to as a "ball contact surface") against which the ball members 31a, 31b, and 31c contact and which is perpendicular to the optical axis AX. As shown in FIG. 9, which will be described later, the ball contact surfaces of the ball holding portions 110a, 110b, and 110c are formed of metal plates 111a, 111b, and 111c with smooth surfaces, respectively. That is, the rear surface fixing and holding member 21 has a surface that is substantially perpendicular to the optical axis AX at a position facing the ball members 31a, 31b, and 31c, and the surface is formed smoothly. The metal plates 111a, 111b, and 111c are fixed to the rear surface fixing and holding member 21 with an adhesive or the like.

[0056] [1-4. Actuator] [1-4-1. Actuator configuration] Next, the configuration of the actuator will be described with reference to FIGS. 4, 5 and 7A.

[0057] The actuator is a drive source for displacing the movable frame 11 (image pickup element 12) relative to the rear fixed holding member 21. As shown in FIGS. 4, 5, and 7A, the actuator is composed of drive coils 15, 16, and 17, and three sets of six pairs of drive magnets (i.e., a pair of drive magnets 25a, 25c and a pair of drive magnets 25b, 25d, a pair of drive magnets 26b, 26d and a pair of drive magnets 27a, 27c, and a pair of drive magnets 27a, 27c and a pair of drive magnets 27b, 27d). The actuator displaces the movable frame 11 relative to the rear fixed holding member 21, thereby correcting image blur caused by movement of the camera body 101.

[0058] As shown in Fig. 4, drive magnets 25a, 25b, 26b, 27a, and 27b are arranged on rear surface fixing member 21, which is arranged on the rear side (opposite the subject) of image sensor 12, so as to face drive coils 15, 16, and 17. As shown in Fig. 7A, drive magnets 25c, 25d, 26d, 27c, and 27d are arranged on front surface fixing member 32, which is arranged on the front side (subject side) of image sensor 12, so as to face drive coils 15, 16, and 17.

[0059] Each of the drive coils 15, 16, and 17 moves from a central position relative to the corresponding set of the three sets of six pairs of drive magnets according to the direction of power supply from the circuit board 13. The three drive coils 15, 16, and 17 are provided to rotate the movable frame 11 (image sensor 12) around the Z axis in a plane perpendicular to the optical axis AX. Specifically, power is supplied to the drive coil 15 to drive it in the positive direction of the X axis shown in FIG. 4, and power is supplied to the drive coil 16 to drive it in the negative direction of the X axis. Rotation around the Z axis occurs, but the center of rotation is not determined. Therefore, the center of rotation can be determined according to the amount and direction of power supply to the drive coil 17. Furthermore, if rotation around the Z axis is not required, drive coils 15 and 16 can be driven in the X axis direction by supplying power in the same phase to the drive coils 15 and 16, and drive coils 17 can be driven in the Y axis direction by supplying power to the drive coil 17. However, since it is difficult to align the center of gravity of the movable frame 11 itself with the center of gravity of the driving force, the amount and direction of power supply to each of the drive coils 15, 16, and 17 are controlled in accordance with the output of a displacement detection unit (described later), and the movable frame 11 is driven in the X-axis direction, Y-axis direction, and roll direction.

[0060] [1-4-2. How to attach the drive magnet] Generally, the magnet is attached to a magnetic body called a yoke, and so with conventional methods, when attaching a magnet to a yoke, the magnet is attracted to the yoke, making it difficult to attach the magnet to the yoke with precision.

[0061] Therefore, in this embodiment, a method is proposed in which the positioning of the magnet relative to the yoke and the bonding of the magnet to the yoke are performed simultaneously, as will be described below.

[0062] As an example of a method for bonding magnets to a yoke, a method for bonding drive magnets 25c, 25d, 26d, 27c, and 27d to front fixed holding member 32 will be described below with reference to Fig. 8. Fig. 8 is a perspective view for explaining a method for bonding drive magnets 25c, 25d, 26d, 27c, and 27d to front fixed holding member 32 according to the embodiment.

[0063] As shown in FIG. 8, in this embodiment, when the drive magnets 25c, 25d, 26d, 27c, and 27d are adhered to the front fixing holding member 32, a suction jig 500 and a base jig 600 are used.

[0064] The attraction jig 500 is a jig for magnetically attracting the drive magnets 25c, 25d, 26d, 27c, and 27d toward the base jig 600. Attracting magnets 525c, 525d, 526d, 527c, and 528c are attached to protruding portions of the attraction jig 500. The attraction magnets 525c, 525d, 526d, 527c, and 528c are arranged corresponding to the drive magnets 25c, 25d, 26d, 27c, and 27d, respectively. The attraction magnets 525c and 527c are magnetized to the north pole on the side facing the base jig 600. The attraction magnets 525d, 526d, and 527d are magnetized to the south pole on the side facing the base jig 600.

[0065] The base jig 600 is a jig for positioning the drive magnets 25c, 25d, 26d, 27c, and 27d relative to the front fixed holding member 32. Positioning portions 601, 602, 603, and 604 are attached to the base jig 600. The positioning portions 601, 602, 603, and 604 are used to position the drive magnets 25c, 25d, 26d, 27c, and 27d. Furthermore, grooves (not shown) are provided on the surface of the base jig 600 facing the suction jig 500, into which the attraction magnets 525c, 525d, 526d, 527c, and 528c attached to the protrusions of the suction jig 500 can be inserted. Furthermore, the base jig 600 is provided with positioning pins 605a and 605b for positioning the front fixed holding member 32 relative to the base jig 600. The front fixed holding member 32 is provided with position restriction holes 701a and 701b for inserting the position restriction pins 605a and 605b, respectively.

[0066] A specific description will now be given of a method for adhering the drive magnets 25c, 25d, 26d, 27c, and 27d to the front fixed holding member 32. As shown in Fig. 8, first, the drive magnets 25c, 25d, 26d, 27c, and 27d are placed on a base jig 600. At this time, the drive magnets 25c, 25d, 26d, 27c, and 27d are positioned relative to the base jig 600 by positioning portions 601, 602, 603, and 604.

[0067] Thereafter, the attracting magnets 525c, 525d, 526d, 527c, and 528c of the attracting jig 500 are inserted into the grooves of the base jig 600, and the attracting magnets 525c, 525d, 526d, 527c, and 528c magnetically attract the drive magnets 25c, 25d, 26d, 27c, and 27d, respectively.

[0068] Thereafter, adhesive is applied to the rear surfaces of the drive magnets 25c, 25d, 26d, 27c, and 27d (i.e., the surfaces facing the front fixed holding member 32). Thereafter, the front fixed holding member 32 is placed on the base jig 600, whereby the drive magnets 25c, 25d, 26d, 27c, and 27d are adhered to the front fixed holding member 32 with the adhesive.

[0069] This allows drive magnets 25c, 25d, 26d, 27c, and 27d to be fixed to front fixed holding member 32, which serves as a yoke, without drilling holes in front fixed holding member 32. Furthermore, because there is no need to provide extra space in front fixed holding member 32 for pouring adhesive into each corner of drive magnets 25c, 25d, 26d, 27c, and 27d, drive magnets 25c, 25d, 26d, 27c, and 27d can be arranged along the periphery of front fixed holding member 32, as shown in Fig. 7B. As a result, by increasing the size of drive magnets 25c, 25d, 26d, 27c, and 27d, a large magnetic force can be secured, while the actuator can be made smaller.

[0070] In this embodiment, the front surface fixing and holding member 32 is installed on the surface of the base jig 600 opposite the suction jig 500, but the front surface fixing and holding member 32 may be sandwiched between the suction jig 500 and the base jig 600. Also, instead of the attraction magnets 525c, 525d, 526d, 527c, and 528c, a coil may be arranged in the suction jig 500 and current may be passed through the coil to magnetically attract the drive magnets 25c, 25d, 26d, 27c, and 27d. Also, in this embodiment, an adhesive is applied to the back surface of each of the drive magnets 25c, 25d, 26d, 27c, and 27d, but an adhesive may be applied to the front surface fixing and holding member 32.

[0071] Furthermore, the above-described bonding method can be applied not only when bonding drive magnets 25c, 25d, 26d, 27c, and 27d to the front fixed holding member 32, but also when bonding drive magnets 25a, 25b, 26b, 27a, and 27b to the rear fixed holding member 21, and can also be applied when bonding sensor magnets 22a, 22b, 23a, 23b, 24a, and 24b to the sensor magnet yoke plate 29 (see Figure 9 described later).

[0072] [1-5. Displacement detection mechanism] Next, the displacement detection mechanism will be described with reference to Figures 5 and 9. Figure 9 is a front view of the rear surface fixing and holding member 21 according to the embodiment.

[0073] As shown in FIGS. 5 and 9, the displacement detection mechanism is made up of magnetic displacement detection sensors 14a, 14b, and 14c and sensor magnets 22a, 22b, 23a, 23b, 24a, and 24b.

[0074] As shown in FIG. 5, magnetic displacement detection sensors 14a, 14b, and 14c are arranged at three locations on the rear side of the imaging element 12 of the circuit board 13. Each of the magnetic displacement detection sensors 14a, 14b, and 14c detects displacement of the imaging element 12 in at least one of the X-axis and Y-axis directions. Another magnetic displacement detection sensor is arranged in either the X-axis or Y-axis direction. In this embodiment, the magnetic displacement detection sensors 14a and 14b are arranged at two locations for detecting displacement in the X-axis direction, and the magnetic displacement detection sensor 14c is arranged at one location for detecting displacement in the Y-axis direction. In this case, the midpoint C of the line connecting the two magnetic displacement detection sensors 14a and 14b that detect displacement in the X-axis direction is set to be approximately the center of the imaging element 12 when forming a magnetic attraction mechanism, which will be described later.

[0075] 9, a pair of sensor magnets 22a and 22b, a pair of sensor magnets 23a and 23b, and a pair of sensor magnets 24a and 24b are arranged at positions corresponding to the magnetic displacement detection sensors 14a, 14b, and 14c, respectively, on the rear surface fixed holding member 21. The sensor magnets 22a, 22b, 23a, 23b, 24a, and 24b are fixed by an adhesive or the like to a sensor magnet yoke plate 29 fixed to the rear surface fixed holding member 21.

[0076] In this embodiment, the sensor magnets 22a, 22b, 23a, 23b, 24a, and 24b are fixed to the sensor magnet yoke plate 29 of the rear surface fixing and holding member 21 with adhesive by the above-mentioned bonding method.

[0077] The displacement detection mechanism described above makes it possible to accurately detect the displacement of the imaging element 12 in at least the X direction, the Y direction, and the roll direction.

[0078] [1-6. Magnetic attraction mechanism] [1-6-1. Configuration of magnetic attraction mechanism] Next, the configuration of the magnetic attraction mechanism will be described with reference to Figures 4, 5, 6 and 9. As shown in Figures 5 and 9, the magnetic attraction mechanism is made up of an attraction plate 19 and sensor magnets 22a, 22b, 23a and 23b.

[0079] 4 and 5, in the ball holding units 110a, 110b, and 110c, unless the image sensor 12 is constantly pressed toward the rear surface fixed holding member 21, the ball members 31a, 31b, and 31c will fall off, preventing smooth rolling movement. Therefore, in this embodiment, an attractive force is applied between the attraction plate 19 and the sensor magnets 22a, 22b, 23a, 23b, 24a, and 24b by utilizing the magnetic force of the sensor magnets 22a, 22b, 23a, 23b, 24a, and 24b toward the magnetic displacement detection sensors 14a, 14b, and 14c. This solves the problems associated with the conventional tension spring system, eliminates the need for space for tension springs, and realizes a compact image stabilization device 1 with high controllability.

[0080] 5 and 6, the suction plate 19 is fixed by adhesive or the like to a holding member 18 attached to the movable frame 11. The holding member 18 is made of, for example, aluminum. The suction plate 19 is positioned so that, when held at the center position within the movable range of the image sensor 12 (i.e., when the suction plate 19 is not displaced relative to the rear surface fixed holding member 21), the center of the suction plate 19 coincides with midpoint C of the gap surrounded by the sensor magnets 22a, 22b, 23a, and 23b in a plane perpendicular to the optical axis AX. The suction plate 19 is also positioned so that two opposing sides 19L1 and 19L3 (see FIG. 10A, described later) of the suction plate 19 are parallel to the X-axis direction, and the remaining two opposing sides 19L2 and 19L4 (see FIG. 10A, described later) are parallel to the Y-axis direction.

[0081] 6, the image sensor 12, circuit board 13, magnetic displacement detection sensors 14a, 14b, and 14c, holding member 18, and attraction plate 19 are arranged in this order along the optical axis AX and are fixed to the movable frame 11 by screw fastening or the like. This configuration allows the attraction plate 19 to attract the sensor magnets 22a, 22b, 23a, and 23b substantially at the center of the image sensor 12, i.e., near the optical axis AX. Therefore, a stable attractive force can be maintained even when the image sensor 12 is displaced.

[0082] [1-6-2. Action of magnetic attraction mechanism] The magnetic attraction force of the attraction plate 19 on the sensor magnets 22a, 22b, 23a, and 23b changes as the movable frame 11 is displaced relative to the rear fixed holding member 21. As the magnetic attraction force changes, the rotational torque acting on the movable frame 11 also changes. Because the rotational torque becomes a load on the actuator when correcting image blur, it is desirable to suppress the rotational torque.

[0083] Here, in order to investigate the relationship between the sensor magnets 22a, 22b, 23a, 23b and the magnetic attractive force (hereinafter referred to as "attractive force") and the rotational torque (hereinafter referred to as "torque"), the following experiments 1 and 2 were carried out.

[0084] [1-6-2-1. Experiment 1] 10A to 13, Experiment 1 will be described below. In Experiment 1, the suction force and torque acting on suction plate 19 when suction plate 19 was moved were compared between Example and Comparative Example 1.

[0085] Fig. 10A is a diagram showing the magnetization of sensor magnets 22a, 22b, 23a, and 23b according to the example. Fig. 10B is a diagram showing the magnetization of sensor magnets 22a, 22b, 23a, and 23b according to comparative examples 1 and 2. Fig. 11 is a graph showing the relationship between the diagonal position of attraction plate 19 and the attractive force acting on attraction plate 19 in the direction of optical axis AX in experiment 1. Fig. 12 is a graph showing the relationship between the diagonal position of attraction plate 19 and the torque acting on attraction plate 19 in experiment 1. Fig. 13 is a diagram showing the torque measurement conditions in experiment 1.

[0086] As shown in FIG. 10A, in the example, similar to the present embodiment, the sensor magnets 22a and 23a were magnetized with the same polarity (S pole) on the side facing the attraction plate 19, and the sensor magnets 22b and 23b were magnetized with the same polarity (N pole) on the side facing the attraction plate 19.

[0087] More specifically, on the side facing attraction plate 19 (the positive side of the Z axis), sensor magnets 22a, 22b, 23a, and 23c each had an S1 magnetized portion which was the S pole of sensor magnet 22a, an N2 magnetized portion of sensor magnet 22b which was the N pole and arranged adjacent to the S1 magnetized portion in the L1 direction (the negative direction of the X axis, an example of a first direction), an S3 magnetized portion of sensor magnet 23a which was the S pole and arranged adjacent to the N2 magnetized portion in the L2 direction (the negative direction of the Y axis, an example of a second direction) that intersects with the L1 direction, and an N4 magnetized portion of sensor magnet 23b which was the N pole and arranged adjacent to the S1 magnetized portion in the L3 direction (the positive direction of the X axis, an example of a third direction) that intersects with the L2 direction. Furthermore, when viewed from the direction of the optical axis AX (Z-axis direction), the attraction plate 19 overlapped at least a part of the S1 magnetized portion, the N2 magnetized portion, the S3 magnetized portion, and the N4 magnetized portion.

[0088] Furthermore, the positions of the S1 magnetized portion, N2 magnetized portion, S3 magnetized portion, and N4 magnetized portion facing the direction of the optical axis AX (on the negative side of the Z axis) were magnetized to the N1 magnetized portion as an N pole, the S2 magnetized portion as an S pole, the N3 magnetized portion as an N pole, and the S4 magnetized portion as an S pole, respectively. The gap between the attraction plate 19 and the sensor magnets 22a, 22b, 23a, and 23b was 0.73 mm. The size of the attraction plate 19 was 6.5 mm x 8.2 mm.

[0089] In the embodiment, the L1 direction and the L2 direction are perpendicular to each other, and the L1 direction and the L3 direction are parallel to each other. However, if the complexity of position detection is acceptable, the L1 direction and the L2 direction do not necessarily have to be perpendicular to each other, and the L1 direction and the L3 direction do not necessarily have to be parallel to each other.

[0090] 10B, in Comparative Example 1, sensor magnets 22a and 23b were magnetized with the same polarity (south pole) on the side facing attraction plate 19, and sensor magnets 22b and 23a were magnetized with the same polarity (north pole) on the side facing attraction plate 19. The gap between attraction plate 19 and sensor magnets 22a, 22b, 23a, and 23b was 0.73 mm. The size of attraction plate 19 was 6.5 mm × 8.2 mm.

[0091] In Experiment 1, the relationship between the diagonal position of the attraction plate 19 and the attractive force acting on the attraction plate 19 was as shown in FIG. 11 . The diagonal position of the attraction plate 19 refers to the position of the attraction plate 19 in the direction of the solid arrows shown in FIGS. 10A and 10B , with the midpoint C (see FIG. 9 ) between the sensor magnets 22 a, 22 b, 23 a, and 23 b as the reference position (diagonal position 0 mm). In FIGS. 10A and 10B , the roughly rectangular frame 19 a shown by the dashed-dotted line represents the attraction plate 19 after movement. As shown in FIG. 11 , it was found that the attractive force acting on the attraction plate 19 was greater in the example than in Comparative Example 1. This indicates that the example can hold the movable frame 11 more stably relative to the rear fixing / holding member 21 than in Comparative Example 1.

[0092] In Experiment 1, the relationship between the diagonal position of the suction plate 19 and the torque acting on the suction plate 19 was as shown in FIG. 12. In Experiment 1, the torque was measured as the rotation moment around the center P1 of the suction plate 19 as the rotation axis, as shown by the solid arrow in FIG. 13. As shown in FIG. 12, it was found that in the Example, the torque was the same as in Comparative Example 1 up to a diagonal position (displacement) of the suction plate 19 of about 1 mm. This shows that in Comparative Example 1, the torque increases when attempting to obtain a suction force equivalent to that of the Example, whereas in the Example, the torque can be suppressed to a level comparable to that of the Comparative Example.

[0093] From the above results, it was confirmed that in the embodiment, it was possible to suppress torque and improve suction force at the same time, reduce the load on the actuator, and make it possible to miniaturize the actuator.

[0094] [1-6-2-2. Experiment 2] 14 to 16, Experiment 2 will be described below. In Experiment 2, the suction force and torque acting on the suction plate 19 when the suction plate 19 was moved were compared between the example and comparative examples 1 and 2.

[0095] Fig. 14 is a graph showing the relationship between the diagonal position of the suction plate 19 and the suction force acting on the suction plate 19 in the direction of the optical axis AX in Experiment 2. Fig. 15 is a graph showing the relationship between the diagonal position of the suction plate 19 and the torque acting on the suction plate 19 in Experiment 2. Fig. 16 is a diagram showing the conditions for measuring the torque in Experiment 2.

[0096] In Experiment 2, the experimental conditions for the example and Comparative Example 1 were the same as those for Experiment 1. In Comparative Example 2, the gap between the attraction plate 19 and the sensor magnets 22a, 22b, 23a, and 23b was narrower by 0.07 mm than in Comparative Example 1. The other experimental conditions for Comparative Example 2 were the same as those for Comparative Example 1.

[0097] In Experiment 2, the relationship between the diagonal position of attraction plate 19 and the attraction force acting on attraction plate 19 was as shown in Fig. 14. As shown in Fig. 14, in Example, as in Experiment 1, it was found that the attraction force acting on attraction plate 19 was greater than in Comparative Examples 1 and 2. In Comparative Example 2, it was found that the attraction force acting on attraction plate 19 was increased by the amount that the gap between attraction plate 19 and sensor magnets 22a, 22b, 23a, and 23b was narrowed by 0.07 mm compared to Comparative Example 1.

[0098] In Experiment 2, the relationship between the diagonal position of the suction plate 19 and the torque acting on the suction plate 19 was as shown in Fig. 15. In Experiment 2, the torque was measured as the rotation moment around the initial position P2 (midpoint C) of the suction plate 19 as the rotation axis, as shown by the solid arrow in Fig. 16. As shown in Fig. 15, in Example, as in Experiment 1, it was found that the torque was closer to zero than in Comparative Examples 1 and 2 when the diagonal position (displacement) of the suction plate 19 was 1.5 mm or more.

[0099] From the above results, it was confirmed that in the embodiment, it was possible to suppress torque and improve suction force at the same time, reduce the load on the actuator, and make it possible to miniaturize the actuator.

[0100] In Comparative Example 2, if the gap between attraction plate 19 and sensor magnets 22a, 22b, 23a, and 23b is narrowed too much in order to increase the attractive force acting on attraction plate 19, the load on the actuator in the X and Y directions tends to increase. In contrast, in the Example, the attractive force acting on attraction plate 19 can be increased without narrowing the gap between attraction plate 19 and sensor magnets 22a, 22b, 23a, and 23b too much, and therefore the load on the actuator in the X and Y directions can be reduced.

[0101] [1-7. Movement restriction mechanism] Next, the configuration of the movement limiting mechanism will be described with reference to Fig. 4. As shown in Fig. 4, the movement limiting mechanism is made up of position limiting members 34a, 34b, and 34c attached to mounting member 33, and position limiting members 36a, 36b, and 36c attached to support posts 35a, 35b, and 35c, respectively.

[0102] As described above, when the ball members 31a, 31b, and 31c come into contact with the respective upright walls 110d, 110e, and 110f of the rectangular ball holders 110a, 110b, and 110c due to displacement of the imaging element 12, a frictional load greater than the rolling load is generated. This frictional load becomes a variable factor in the driving force of the actuator, making accurate image stabilization control difficult. Furthermore, when an unexpected impact or the like is applied, there is a risk that the ball members 31a, 31b, and 31c will climb over the respective upright walls 110d, 110e, and 110f and fall off.

[0103] 4, in this embodiment, to prevent abnormal noise from occurring when the movable frame 11 moves relative to the rear surface fixed holding member 21 and abuts against the mounting member 33 and the pillars 35a, 35b, 35c, position restriction members 34a, 34b, 34c are attached to the mounting member 33, and position restriction members 36a, 36b, 36c are attached to the pillars 35a, 35b, 35c, respectively. The movable frame 11 abuts against the mounting member 33 via the position restriction members 34a, 34b, 34c, and abuts against the pillars 35a, 35b, 35c via the position restriction members 36a, 36b, 36c.

[0104] Furthermore, by bringing the center of gravity of the movable frame 11 in the direction of the optical axis AX into contact with the position restriction members 34a, 34b, 34c, 36a, 36b, and 36c, it is possible to suppress the rotation moment and rotation in the yaw and pitch directions, and to prevent the movable frame 11 from coming into contact with the rear fixed holding member 21 and the front fixed holding member 32. The position restriction members 34a, 34b, 34c, 36a, 36b, and 36c have cushioning properties and also serve to absorb impacts.

[0105] [2. Operation] Next, the operation of image shake correction device 1 according to this embodiment will be described. When digital camera 100 is capturing an image, if camera body 101 moves and the optical axis of light from the subject deviates from the center of image sensor 12, magnetic displacement detection sensors 14a, 14b, and 14c detect the direction and amount of displacement of image sensor 12 in the left-right, up-down, yaw, pitch, and roll directions. The detected direction and amount of displacement are measured by circuit board 13, and the controller of circuit board 13 supplies power to drive coils 15, 16, and 17 in accordance with the measurement results.

[0106] At this time, the circuit board 13 supplies power to at least one of the drive coils 15, 16, and 17 in accordance with the measured amount and direction of displacement. This power supply changes the magnetic force on the corresponding drive magnets 25a, 25b, 25c, 25d, 27a, 27c, 26b, 26d, 27a, 27b, 27c, and 27d, displacing the movable frame 11 relative to the rear fixed holding member 21. As a result, the image sensor 12 fixed to the movable frame 11 is displaced in a direction and by an amount that corrects image blur.

[0107] [3.Effects] The image blur correction device 1 according to this embodiment is an image sensor driving device for driving an image sensor 12. The image blur correction device 1 includes a rear fixed holding member 21, a movable frame 11 for holding the image sensor 12, the movable frame 11 facing the rear fixed holding member 21 in the optical axis AX direction and displaceable relative to the rear fixed holding member 21 in a plane perpendicular to the optical axis AX direction, an attraction plate 19 provided on one of the rear fixed holding member 21 and the movable frame 11, and at least one sensor magnet 22a, 22b, 23a, 23b provided on the other of the rear fixed holding member 21 and the movable frame 11 and facing the attraction plate 19 in the optical axis AX direction. At least one of the sensor magnets 22a, 22b, 23a, 23b has, on the side facing the attraction plate 19, an S1 magnetized portion magnetized to an S pole, an N2 magnetized portion arranged adjacent to the S1 magnetized portion in the L1 direction and magnetized to an N pole, an S3 magnetized portion arranged adjacent to the N2 magnetized portion in the L2 direction intersecting with the L1 direction and magnetized to an S pole, and an N4 magnetized portion magnetized to an N pole and arranged adjacent to the S3 magnetized portion in the L3 direction intersecting with the L2 direction and adjacent to the S1 magnetized portion. When viewed from the direction of the optical axis AX, the attraction plate 19 overlaps at least a portion of the S1 magnetized portion, the N2 magnetized portion, the S3 magnetized portion, and the N4 magnetized portion.

[0108] This makes it possible to increase the attractive force between the attraction plate 19 and the sensor magnets 22a, 22b, 23a, and 23b while suppressing the rotational torque acting on the attraction plate 19. As a result, it is possible to reduce the load on the actuator, and it is possible to maintain a stable attractive force by the attraction plate 19 even when the imaging element 12 is displaced. Therefore, it is possible to drive the imaging element 12 stably.

[0109] Furthermore, in this embodiment, at least one of sensor magnets 22a, 22b, 23a, 23b further includes an N1 magnetized portion that is arranged opposite the S1 magnetized portion in the direction of the optical axis AX and is magnetized to the N pole, an S2 magnetized portion that is arranged opposite the N2 magnetized portion in the direction of the optical axis AX and is magnetized to the S pole, an N3 magnetized portion that is arranged opposite the S3 magnetized portion in the direction of the optical axis AX and is magnetized to the N pole, and an S4 magnetized portion that is arranged opposite the N4 magnetized portion in the direction of the optical axis AX and is magnetized to the S pole.

[0110] This makes it possible to increase the magnetic force in the direction of the optical axis AX, and to drive the image pickup element 12 more stably even when the image pickup element 12 is displaced.

[0111] Furthermore, in this embodiment, a plurality of magnets are provided, and the plurality of magnets include sensor magnet 22a having an S1 magnetized portion formed thereon, sensor magnet 22b having an N2 magnetized portion formed thereon, sensor magnet 23a having an S3 magnetized portion formed thereon, and sensor magnet 23b having an N4 magnetized portion formed thereon.

[0112] This allows each of the sensor magnets 22a, 22b, 23a, and 23b to be configured with a unidirectionally magnetized (NS magnetized) magnet. As a result, each of the sensor magnets 22a, 22b, 23a, and 23b can be configured inexpensively. Furthermore, because the spacing between the sensor magnets 22a, 22b, 23a, and 23b can be adjusted, the detection sensitivity of the magnetic displacement detection sensors 14a, 14b, and 14c can be easily adjusted compared to when each sensor magnet is configured with a single magnet.

[0113] Furthermore, in this embodiment, the image shake correction device 1 further includes magnetic displacement detection sensors 14a, 14b, and 14c that detect displacement of the movable frame 11 relative to the rear fixed holding member 21 based on changes in the magnetic flux of at least one sensor magnet 22a, 22b, 23a, and 23b, and the magnetic displacement detection sensors 14a, 14b, and 14c are provided on the other of the rear fixed holding member 21 and the movable frame 11 and face the at least one sensor magnet 22a, 22b, 23a, and 23b in the direction of the optical axis AX.

[0114] This allows the imaging element 12 to be driven stably even when the imaging element 12 is displaced, and as a result, the position to which the imaging element 12 has been displaced can be detected with high precision.

[0115] Furthermore, in this embodiment, the image shake correction device 1 further includes an actuator that displaces the movable frame 11 relative to the rear fixed holding member 21. The magnetic displacement detection sensors 14a, 14b, and 14c detect the amount and direction of displacement of the movable frame 11 relative to the rear fixed holding member 21. The actuator displaces the movable frame 11 relative to the rear fixed holding member 21 based on the detected amount and direction of displacement of the movable frame 11.

[0116] This makes it possible to correct image blur caused by movement of the camera body 101.

[0117] In this embodiment, the movable frame 11, the magnetic displacement detection sensors 14a, 14b, and 14c, the attraction plate 19, and the sensor magnets 22a, 22b, 23a, and 23b are arranged in this order along the optical axis AX.

[0118] This allows the suction plate 19 to maintain a stable suction force even when the imaging element 12 is displaced.

[0119] Moreover, in this embodiment, the image shake correction device 1 further includes ball members 31a, 31b, and 31c that support the movable frame 11 so that it can be displaced relative to the rear surface fixed holding member 21. The ball members 31a, 31b, and 31c are pressed against the movable frame 11 or the rear surface fixed holding member 21 as a result of the attraction plate 19 being attracted to at least one of the sensor magnets 22a, 22b, 23a, and 23b.

[0120] This allows the ball members 31a, 31b, and 31c to be biased toward one side of the rear surface fixing holding member 21 and the movable frame 11.

[0121] Furthermore, in this embodiment, when the movable frame 11 is not displaced relative to the rear surface fixed holding member 21, the attraction plate 19 is arranged so that the center of the attraction plate 19 and the midpoint C of the S1 magnetized portion, the N2 magnetized portion, the S3 magnetized portion, and the N4 magnetized portion are aligned along the optical axis AX.

[0122] This allows the image sensor 12 to be stably attracted in the direction of the optical axis AX, making it easier to control the actuator when displacing the image sensor 12. As a result, the image sensor 12 can be displaced to the target position with higher accuracy.

[0123] In this embodiment, the cross section of the suction plate 19 perpendicular to the direction of the optical axis AX is formed in a circular or substantially polygonal shape.

[0124] This allows the image sensor 12 to be attracted more stably in the direction of the optical axis AX, making it easier to control the actuator when moving the image sensor 12. As a result, the image sensor can be displaced to the target position with higher accuracy.

[0125] In this embodiment, the image blur correction device 1 further includes a movement limiting mechanism that limits the movement of the movable frame 11 relative to the rear surface fixing and holding member 21.

[0126] This allows the imaging element 12 to be accurately displaced to the target position.

[0127] Furthermore, in this embodiment, the movement limiting mechanism has position restriction members 34a, 34b, 34c, 36a, 36b, and 36c. The position restriction members 34a, 34b, 34c, 36a, 36b, and 36c are arranged so as to come into contact with the center of gravity of the movable frame 11 in the direction of the optical axis AX when the movable frame 11 comes into contact with the position restriction members 34a, 34b, 34c, 36a, 36b, and 36c.

[0128] This makes it possible to prevent the ball members 31a, 31b, and 31c from climbing over the standing walls 110d, 110e, and 110f and falling off when an unexpected impact or the like is applied.

[0129] The digital camera 100 of this embodiment includes any of the image shake correction devices 1 described above and an image sensor 12 that converts an optical image of a subject into an electrical signal. The movable frame 11 holds the image sensor 12 so that it can be displaced relative to the rear fixed holding member 21.

[0130] This makes it possible to provide a digital camera 100 with a higher performance image stabilization function.

[0131] The digital camera 100 of this embodiment includes the image stabilization device 1 described above and a plurality of optical systems that collect light from a subject. The movable frame 11 holds at least one of the optical systems so that it can be displaced relative to the rear fixed holding member 21.

[0132] This makes it possible to provide a digital camera 100 with a higher performance image stabilization function.

[0133] In addition, the manufacturing method of the image blur correction device 1 of this embodiment is a manufacturing method of the image blur correction device 1 that includes a front fixed holding member 32 and drive magnets 25c, 25d, 26d, 27c, and 27d fixed to the front fixed holding member 32. The manufacturing method of the image blur correction device 1 includes the steps of (a) placing the drive magnets 25c, 25d, 26d, 27c, and 27d on a base jig 600, (b) attracting the drive magnets 25c, 25d, 26d, 27c, and 27d toward the base jig 600 using a suction jig 500, (c) applying adhesive to one of the drive magnets 25c, 25d, 26d, 27c, and 27d and the front fixed holding member 32, and (d) installing the front fixed holding member 32 on the base jig 600, thereby fixing the drive magnets 25c, 25d, 26d, 27c, and 27d to the front fixed holding member 32 via the adhesive.

[0134] This allows drive magnets 25c, 25d, 26d, 27c, and 27d to be fixed to front fixed holding member 32, which serves as a yoke, without drilling holes in front fixed holding member 32. Furthermore, because there is no need to ensure extra space in front fixed holding member 32 for pouring adhesive into each corner of drive magnets 25c, 25d, 26d, 27c, and 27d, drive magnets 25c, 25d, 26d, 27c, and 27d can be arranged along the periphery of front fixed holding member 32. As a result, by increasing the size of drive magnets 25c, 25d, 26d, 27c, and 27d, it is possible to achieve a compact actuator while ensuring a large magnetic force.

[0135] In this embodiment, the suction jig 500 has suction magnets 525c, 525d, 526d, 527c, and 527d that are arranged at positions corresponding to the drive magnets 25c, 25d, 26d, 27c, and 27d that are placed on the base jig 600. In the above (b), the drive magnets 25c, 25d, 26d, 27c, and 27d are attracted toward the base jig 600 by the magnetic forces of the suction magnets 525c, 525d, 526d, 527c, and 527d of the suction jig 500.

[0136] This allows the drive magnets 25c, 25d, 26d, 27c, and 27d to be held relative to the base jig 600 when the front surface fixing and holding member 32 is installed on the base jig 600.

[0137] In this embodiment, the base jig 600 has positioning portions 601, 602, 603, and 604 for positioning the drive magnets 25c, 25d, 26d, 27c, and 27d. In the above (a), the drive magnets 25c, 25d, 26d, 27c, and 27d are placed on the base jig 600 so that the drive magnets 25c, 25d, 26d, 27c, and 27d are positioned relative to the base jig 600 by the positioning portions 601, 602, 603, and 604.

[0138] This allows the drive magnets 25c, 25d, 26d, 27c, and 27d to be positioned relative to the base jig 600 easily.

[0139] In this embodiment, the base jig 600 has position restriction pins 605a and 605b. The front surface fixed holding member 32 has position restriction holes 701a and 701b through which the position restriction pins 605a and 605b are inserted. In the above (d), the front surface fixed holding member 32 is installed on the base jig 600 so that the position restriction pins 605a and 605b are inserted into the position restriction holes 701a and 701b.

[0140] This allows the front surface fixing and holding member 32 to be easily positioned relative to the base jig 600.

[0141] Moreover, the image shake correction device 1 of this embodiment is an image sensor driving device for driving the image sensor 12. It includes a front fixed holding member 32 having a fixing surface, and drive magnets 25c, 25d, 26d, 27c, and 27d that are used to drive the image sensor 12 and are fixed with an adhesive to the fixing surface of the front fixed holding member 32. The entire back surface of each of the drive magnets 25c, 25d, 26d, 27c, and 27d is in contact with the fixing surface of the front fixed holding member 32 via the adhesive.

[0142] This allows drive magnets 25c, 25d, 26d, 27c, and 27d to be fixed to front fixed holding member 32, which serves as a yoke, without drilling holes in front fixed holding member 32. Furthermore, because there is no need to ensure extra space in front fixed holding member 32 for pouring adhesive into each corner of drive magnets 25c, 25d, 26d, 27c, and 27d, drive magnets 25c, 25d, 26d, 27c, and 27d can be arranged along the periphery of front fixed holding member 32. As a result, by increasing the size of drive magnets 25c, 25d, 26d, 27c, and 27d, it is possible to achieve a compact actuator while ensuring a large magnetic force.

[0143] (Variations, etc.) As described above, the embodiments have been described as examples of the technology disclosed in this application. However, the technology in this disclosure is not limited to these, and can be applied to embodiments in which appropriate modifications, substitutions, additions, omissions, etc. are made. Furthermore, it is also possible to combine the components described in each of the above embodiments to create new embodiments.

[0144] Therefore, other embodiments will be exemplified below.

[0145] [1] In the above embodiment, the cross-sectional shape of the suction plate 19 is formed to be substantially rectangular, but this is not limiting. For example, the cross-sectional shape of the suction plate 19 may be formed to be circular or substantially polygonal.

[0146] [2] In the above embodiment, a configuration for stably attracting the image sensor 12 in the direction of the optical axis AX in the image stabilization device 1 has been described, but the concept of the present disclosure is not limited to the image stabilization device 1. For example, the present disclosure may be applied to an imaging device disclosed in Japanese Patent Application Laid-Open No. 2011-227578, which drives the image sensor over a range smaller than the number of pixels of the image sensor to obtain image data with a higher resolution than the actual number of pixels of the image sensor. Alternatively, the present disclosure may be applied to an imaging device disclosed in Japanese Patent Application Laid-Open No. 2010-73035, which drives the image sensor pixel by pixel to obtain information on each of the RGB colors for each pixel to obtain high-resolution image data.

[0147] [3] In the above embodiment, the sensor magnets 22a, 22b, 23a, 23b, 24a, and 24b are arranged on the rear surface fixed holding member 21, but this is not limitative and they may be arranged on the movable frame 11. In this case, the magnetic displacement detection sensors 14a, 14b, and 14c and the attraction plate 19 are arranged on the rear surface fixed holding member 21.

[0148] [4] 1 and 2 has been given as an example of an imaging device in the above embodiment, but the imaging device is not limited to this. The imaging device may be, for example, a camera system that can be equipped with an image stabilization device using either a sensor shift method or a lens shift method.

[0149] [5] In the above embodiment, the actuator is configured with the drive coils 15, 16, 17 and three sets of six pairs of drive magnets, but is not limited to this and may be configured with, for example, a piezoelectric actuator.

[0150] [6] In the above embodiment, each of the magnetic displacement detection sensors 14a, 14b, and 14c is configured using a Hall element, but this is not limited to this and may be configured using a sensor that detects displacement from an integrated value using, for example, an angular velocity sensor or an acceleration sensor.

[0151] As described above, the embodiments have been described as examples of the technology in the present disclosure, and for that purpose, the accompanying drawings and detailed description have been provided.

[0152] Therefore, the components shown in the accompanying drawings and detailed description may include not only essential components for solving the problem, but also components that are not essential for solving the problem in order to illustrate the above technology. Therefore, the fact that these non-essential components are shown in the accompanying drawings or detailed description should not be interpreted as immediately indicating that these non-essential components are essential.

[0153] Furthermore, since the above-described embodiments are intended to illustrate the technology of the present disclosure, various modifications, substitutions, additions, omissions, etc. may be made within the scope of the claims or their equivalents. [Industrial Applicability]

[0154] The image sensor driving device disclosed herein has an image shake correction function and a pixel shift shooting function by driving the image sensor, and can be widely applied to electronic devices capable of capturing subject images (e.g., image sensors such as digital cameras and camcorders, camera bodies, mobile phones, smartphones, etc.). [Explanation of symbols]

[0155] 1 Image stabilization device 10. Cabinet 11 Movable frame 12 Image sensor 13 Circuit Board 14a, 14b, 14c magnetic displacement detection sensors 15 drive coil 16 drive coil 17 Drive coil 18 Retaining member 19,19a Suction plate 20 Body Mount 20a opening 21 Rear fixing member 22a, 22b, 23a, 23b, 24a, 24b Sensor magnets 25a, 25b, 25c, 25d, 26b, 26d, 27a, 27b, 27c, 27d Drive magnet 28 Adhesive 29 Sensor magnet yoke plate 30 Shutter button 31a, 31b, 31c ball members 32 Front fixed holding member 33 Mounting material 34a, 34b, 34c, 36a, 36b, 36c position regulation members 35a,35b,35c pillar 40 Hot shoe 50 Flash unit 60 Electronic Viewfinder 70 Display device 100 digital cameras 101 Camera body 110a, 110b, 110c ball holding portion 110d, 110e, 110f Standing wall 111a,111b,111c Metal plate 200 Lens Unit 201 Lens mount 202 Focus ring 203 Zoom Ring 500 Suction Jig 525c,525d,526d,527c,527d Attraction magnet 600 base jig 601,602,603,604 Positioning part 605a, 605b Position control pin 701a,701b Position regulation hole AX optical axis S1 front S2 top S3 rear S4 bottom

Claims

1. An imaging element driving device for driving an imaging element, a yoke having a fixed surface; a first magnet, a second magnet, and a third magnet, each of which is fixed to the fixed surface of the yoke and is used to drive the imaging element; an inner periphery of the yoke is formed so that the imaging element is exposed when the yoke and the imaging element are viewed from the optical axis direction; the first magnet is located on the inner periphery side of the yoke, the second magnet is located on the outer circumferential side of the yoke relative to the first magnet, the third magnet is located on one side of the first magnet and the second magnet in a direction along the circumferential direction of the yoke, when the yoke and the imaging element are viewed from the optical axis direction, a surface of the first magnet is one of an S pole and an N pole, and surfaces of the second magnet and the third magnet are each a magnetic pole different from a surface of the first magnet; The side surface of the inner periphery of the yoke, which faces the first magnet, is disposed so as to be substantially hidden by the first magnet when the yoke is viewed from the optical axis direction. Image sensor driving device.

2. An imaging element driving device for driving an imaging element, a yoke having a fixed surface; a first magnet, a second magnet, and a third magnet, each of which is fixed to the fixed surface of the yoke and is used to drive the imaging element; When the yoke and the imaging element are viewed from the optical axis direction, an inner periphery of the yoke is formed so that the imaging element is exposed, the first magnet is located on the inner periphery side of the yoke, the second magnet is located on the outer circumferential side of the yoke relative to the first magnet, the third magnet is located on one side of the first magnet and the second magnet in a direction along the circumferential direction of the yoke, when the yoke and the imaging element are viewed from the optical axis direction, a surface of the first magnet is one of an S pole and an N pole, and surfaces of the second magnet and the third magnet are each a magnetic pole different from a surface of the first magnet; When the yoke and the first magnet are viewed from the optical axis direction, the first magnet is fixed to the yoke such that a portion of the inner periphery of the yoke is substantially hidden by the first magnet. Image sensor driving device.

Images