Image blur correction device and imaging device

Abstract

Provided are an image blur correction device and an imaging device having suppressed influence from another magnetic body on a ball receiving surface. This image blur correction device (100) comprises: a mobile part (101) which has an imaging element (16) and a plurality of coils, and is movably supported within a plane parallel to an imaging surface of the imaging element (16); a stationary part (102) which supports the mobile part, and has a plurality of magnets and a yoke disposed facing the plurality of coils; and a ball clamped between the mobile part (101) and the stationary part (102), wherein the mobile part (101) has a ball accommodation part formed by a hollow protrusion that accommodates the ball, and a ball receiving surface provided to the bottom of the ball accommodation part is formed of a non-magnetic metal material.

Description

Image stabilization device and imaging device

[0001] The present invention relates to an image stabilization device and an imaging device.

[0002] Conventionally, a camera technology has been proposed in which an image stabilization device is attached to an image sensor.

[0003] For example, Japanese Patent Application Laid-Open No. 2003-124992 describes a technique relating to a camera equipped with an image stabilization device that allows an image sensor to move in two directions perpendicular to the optical axis of the photographing optical system.

[0004] Japanese Patent Application Laid-Open No. 2016-131265

[0005] One embodiment of the technique of the present disclosure provides an image stabilization device and an imaging device in which the influence of other magnetic materials on the ball receiving surface is suppressed.

[0006] An image stabilization device according to a first aspect of the present invention comprises: a movable section having an image sensor and a plurality of coils, and being supported so as to be movable within a plane parallel to the imaging surface of the image sensor; a fixed section supporting the movable section, the fixed section having a plurality of magnets and a yoke and arranged opposite the plurality of coils; and a ball held between the movable section and the fixed section, wherein the movable section has a ball receiving section formed by a hollow protrusion that receives the ball, and a ball receiving surface provided at the bottom of the ball receiving section is made of a non-magnetic metallic material.

[0007] Preferably, the fixed part is composed of a first yoke and a second yoke spaced apart from the first yoke, the movable part is disposed between the first yoke and the second yoke, the second yoke is provided with a plurality of magnets, and the ball accommodating part is provided on the second yoke side of the movable part.

[0008] Preferably, the ball receiving portion is provided on the movable portion opposite the second yoke.

[0009] Preferably, the ball receiving portion is disposed between the plurality of magnets.

[0010] Preferably, the ball receiving portion has an elastic member provided on an outer peripheral side surface of the hollow protrusion.

[0011] Preferably, the second yoke is provided with an abutment portion that abuts against at least one side surface of the plurality of magnets.

[0012] Preferably, the first yoke and the second yoke are connected via a shaft member, the abutment portion is formed on a convex side surface of the second yoke, and the shaft member is provided on an upper surface of the convex shape.

[0013] Preferably, the ball receiving surface has a surface hardness of HV300 or more.

[0014] Preferably, the ball receiving surface has a surface roughness Ra of 0.4 μm or less.

[0015] An imaging apparatus according to another aspect of the present invention includes the above-described image stabilization device.

[0016] Preferably, the imaging device is equipped with a processor, which controls the movement of the movable part using a drive mechanism composed of multiple coils and some or all of the multiple magnets, and when the ball receiving surface is made of a magnetic material, controls the movement without applying resistance to the magnetic force received from at least one of the multiple magnets.

[0017] FIG. 1 is a schematic diagram of the interior of an imaging apparatus equipped with an image stabilization device. FIG. 2 is a block diagram showing an embodiment of the internal configuration of the imaging apparatus. FIG. 3 is a front perspective view of the image stabilization device. FIG. 4 is a rear perspective view of the image stabilization device. FIG. 5 is a front perspective view of a fixed portion. FIG. 6 is a rear perspective view of a movable portion. FIG. 7 is a bottom perspective view of the image stabilization device. FIG. 8 is an enlarged view of region R in FIG. 7. FIG. 9 is a diagram illustrating the load applied to the ball receiving surface. FIG. 10 is a diagram illustrating Vickers hardness (HV). FIG. 11 is an enlarged view of the vicinity of the damper member (region V in FIG. 6). FIG. 12 is a diagram illustrating movement of the movable portion. FIG. 13 is a diagram illustrating movement of the movable portion. FIG. 14 is a cross-section of the portion indicated by W in FIG. 11. FIG. 15 is a diagram illustrating an abutment portion. FIG. 16 is a diagram illustrating another example of the abutment portion. FIG. 17 is a diagram illustrating another example of the abutment portion. FIG. 18 is a diagram illustrating an example in which a shaft is provided on a convex portion.

[0018] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of an image stabilization device and an imaging device according to the present invention will now be described with reference to the accompanying drawings.

[0019] <Imaging Apparatus> First, an imaging apparatus incorporating an image stabilization device will be described.

[0020] FIG. 1 is a schematic diagram showing the inside of an image pickup apparatus equipped with an image stabilization device according to the present invention.

[0021] The imaging device 10 is an interchangeable lens camera, and a photographic lens device 12 is attached to an imaging device body 2 via an adapter 6. The photographic lens device 12 includes an aperture 8 and lens groups 12A and 12B. The photographic lens device 12, which has an optical axis L, forms an image using light reflected from a subject 1. The imaging device body 2 includes an eyepiece 4, and when photographing the subject 1, the photographer places their eye near the eyepiece 4 to photograph the subject 1.

[0022] The image sensor 16 has a light receiving surface (imaging surface) arranged along a plane (X-Y plane) formed by two directions (X direction and Y direction) that perpendicularly intersect with the optical axis L of the image sensor body 2. The image sensor 16 is held by the image stabilization device 100. The image stabilization function is realized by controlling the drive unit 58 included in the image stabilization device 100 by the control unit 40.

[0023] 2 is a block diagram showing an embodiment of the internal configuration of the imaging device 10. This imaging device 10 records captured images on a memory card 54, and the operation of the entire device is centrally controlled by a control unit 40 (CPU: Central Processing Unit).

[0024] The imaging device 10 is provided with an operation unit 38 including a shutter button, a power / mode switch, a mode dial, a cross button, etc. Signals (commands) from this operation unit 38 are input to a control unit 40, which controls each circuit of the imaging device 10 based on the input signals, and performs drive control of the imaging element 16, lens drive control, aperture drive control, imaging operation control, image processing control, image data recording / playback control, and display control of the image monitor 30.

[0025] The light beam passing through the photographing lens device 12 forms an image on the image sensor 16, which is a CMOS (Complementary Metal-Oxide Semiconductor) color image sensor. The image sensor 16 is not limited to the CMOS type, and other types of image sensors such as a CCD (Charge Coupled Device) type or an organic image sensor may also be used.

[0026] The image sensor 16 has a large number of light-receiving elements (e.g., photodiodes) arranged two-dimensionally, and the subject image formed on the light-receiving surface of each light-receiving element is converted (photoelectrically converted) into a signal voltage (or charge) of an amount corresponding to the amount of incident light, and then converted into a digital signal via an A / D (Analog / Digital) converter within the image sensor 16 and output.

[0027] Image signals (image data) read from the image sensor 16 when capturing a moving image or a still image are temporarily stored in a memory (SDRAM (Synchronous Dynamic Random Access Memory)) 48 via the image input controller 22 .

[0028] Furthermore, a flash memory 47 stores a camera control program and various parameters and tables used for image processing and the like.

[0029] The sensor 66 is a camera shake sensor that detects attitude information and attitude change information of the imaging device 10. The sensor 66 is configured, for example, by a gyro sensor. The sensor 66 is configured, for example, by two gyro sensors for detecting the amount of camera shake in the vertical direction and the amount of camera shake in the horizontal direction, and the detected amounts of camera shake (angular velocity) are input to the control unit 40. The control unit 40 controls the drive unit 58 to move the image sensor 16 so as to cancel movement of the subject image due to camera shake, thereby performing image blur correction.

[0030] The driving unit 58 is controlled by the control unit 40. The driving unit (driving mechanism) 58 is configured by a voice coil motor, which will be described later.

[0031] The image processing unit 24 reads unprocessed image data that is acquired via the image input controller 22 when capturing moving images or still images and that is temporarily stored in the memory 48. The image processing unit 24 performs offset processing, pixel interpolation processing (interpolation processing for phase difference detection pixels, defective pixels, etc.), white balance correction, gain control processing including sensitivity correction, gamma correction processing, synchronization processing (also called "demosaic processing"), luminance and color difference signal generation processing, contour enhancement processing, color correction, etc. The image data that has been processed by the image processing unit 24 and that has been processed as a live view image is input to a VRAM (Video RAM Random Access Memory) 50.

[0032] The image data read from the VRAM 50 is encoded by the video encoder 28 and output to the image monitor 30 provided on the rear surface of the camera. As a result, a live view image showing the subject image is displayed on the image monitor 30.

[0033] The image data (brightness data (Y) and color difference data (Cb), (Cr)) processed by the image processing unit 24 as a still image or a moving image for recording is stored again in the memory 48.

[0034] When recording a still image or a moving image, the compression / decompression processing unit 26 performs compression processing on the luminance data (Y) and color difference data (Cb, Cr) processed by the image processing unit 24 and stored in the memory 48. The compressed image data is recorded on a memory card 54 via a media controller 52.

[0035] In addition, in the playback mode, the compression / decompression processing unit 26 performs decompression processing on compressed image data obtained from the memory card 54 via the media controller 52. The media controller 52 records and reads compressed image data onto and from the memory card 54.

[0036] In the above embodiment, the hardware structure of the processing unit (such as the control unit 40) that executes various processes is the following various processors: The various processors include a CPU (Central Processing Unit), which is a general-purpose processor that executes software (programs) and functions as various processing units, a programmable logic device (PLD), such as an FPGA (Field Programmable Gate Array), whose circuit configuration can be changed after manufacture, and a dedicated electrical circuit, such as an ASIC (Application Specific Integrated Circuit), which is a processor with a circuit configuration designed specifically for executing specific processes.

[0037] A single processing unit may be configured with one of these various processors, or may be configured with two or more processors of the same or different types (e.g., multiple FPGAs, or a combination of a CPU and an FPGA). Multiple processing units may also be configured with a single processor. Examples of multiple processing units configured with a single processor include: a first configuration, as typified by client or server computers, in which a single processor is configured with a combination of one or more CPUs and software, and this processor functions as multiple processing units; and a second configuration, as typified by system-on-chip (SoC), in which a processor is used to realize the functions of an entire system including multiple processing units on a single IC (Integrated Circuit) chip. In this way, the various processing units are configured with one or more of the above-mentioned various processors as a hardware structure.

[0038] Furthermore, the hardware structure of these various processors is, more specifically, an electric circuit made up of a combination of circuit elements such as semiconductor elements.

[0039] <Image Shake Correction Device> Next, the image shake correction device 100 will be described.

[0040] 3, 4, 5, and 6 are diagrams showing the image stabilization device 100 mounted on the imaging device 10. Fig. 3 is a front perspective view of the image stabilization device 100, Fig. 4 is a rear perspective view of the image stabilization device 100, Fig. 5 is a front perspective view of the fixed unit 102, and Fig. 6 is a rear perspective view of the movable unit 101. In the following description, the front refers to the surface seen from the positive Z axis side (the subject side), and the rear refers to the surface seen from the negative Z axis side (the photographer side).

[0041] The image stabilization device 100 is mainly composed of a movable section 101 on which the image sensor 16 is mounted, and a fixed section 102 that is fixed to the image capture device body 2. The movable section 101 abuts against the fixed section 102 via three balls 131. The movable section 101 is biased toward the fixed section 102 (second yoke 105) by the attraction force of a magnet (not shown) or the elastic force of a spring, and the three balls 131 are sandwiched between the movable section 101 and the fixed section 102. The movable section 101 can also move within a plane (the X-Y plane in the figure) that is perpendicular to the optical axis L (the Z-axis in the figure).

[0042] The fixed part 102 is composed of a first yoke 103 and a second yoke 105. The first yoke 103 is disposed on the subject 1 side, and the second yoke 105 is disposed on the photographer side. The fixed part 102 is fixed to the imaging device body 2 by a mechanism (not shown).

[0043] The first yoke 103 is disposed at a position facing and spaced apart from the second yoke 105 by the shafts 121, 123, and 125. The shafts 121, 123, and 125 also function as movable end stoppers on the fixed part 102 side.

[0044] The second yoke 105 is disposed opposite to and spaced apart from the first yoke 103. The second yoke 105 includes a magnet 113b, a magnet 115b, a magnet 117b, and a magnet 119. The magnet 113b and a coil 113a provided in the movable part 101 constitute a voice coil motor 113. The magnet 115b and a coil 115a provided in the movable part 101 constitute a voice coil motor 115. The magnet 117b and a coil 117a provided in the movable part 101 constitute a voice coil motor 117. The magnets 115b, 117b, and 119 are also used as magnets for Hall element detection that detects the position of the movable part 101. The magnet 113b is a magnet dedicated to the voice coil motor 113.

[0045] The second yoke 105 has a movable end restricting opening 141 and a movable end restricting opening 143. The shafts 133 and 135 of the movable part 101 are inserted into the movable end restricting opening 141 and the movable end restricting opening 143. The movable end restricting opening 141, the movable end restricting opening 143, and the shafts 133 and 135 constitute a movable end restricting part that restricts the movement range of the movable part 101.

[0046] When camera shake or the like occurs, the movable part 101 is driven by the voice coil motor 113, the voice coil motor 117, and the voice coil motor 115 in a direction that cancels out the camera shake. This reduces the influence of camera shake on the image captured by the image sensor 16 mounted on the movable part 101. The voice coil motor 113, the voice coil motor 117, and the voice coil motor 115 form a driving part 58.

[0047] The movable part 101 has ball accommodating portion 107, ball accommodating portion 109, and ball accommodating portion 111 on the surface facing the second yoke 105. Each of ball accommodating portion 107, ball accommodating portion 109, and ball accommodating portion 111 has a shape that accommodates a ball 131. For example, ball accommodating portion 107 and ball accommodating portion 109 have a concave shape, and ball 131 is accommodated in the concave shape. Furthermore, ball accommodating portion 111 has a hollow protruding portion, and ball 131 is accommodated in the hollow protruding portion. Each of balls 131 accommodated in ball accommodating portion 107, ball accommodating portion 109, and ball accommodating portion 111 is rollable. Therefore, the movable part 101 can move freely on a plane (X-Y plane) perpendicular to the optical axis L. Ball accommodating portion 107, ball accommodating portion 109, and ball accommodating portion 111 have ball receiving surfaces 107a, 109a, and 111a, respectively, at their bottoms. Note that second yoke 105 is provided with ball receiving surfaces 107b (not shown), 109b, and 111b on the fixed portion 102 side. Also, a damper member 151 is provided on the outer peripheral side surface of ball accommodating portion 111.

[0048] <Ball Receiving Surface> Next, the ball receiving surface 111a disposed at the bottom of the ball receiving portion 111 provided in the movable portion 101 will be described in detail.

[0049] 7 and 8 are diagrams illustrating the ball receiving portion 111. Fig. 7 is a bottom perspective view of the image stabilization device 100, and Fig. 8 is an enlarged view of a region R in Fig. 7.

[0050] Ball housing 111 is provided so as to be located between magnet 117b and magnet 119. In image stabilization device 100, the space between ball housing 111 and magnet 117b, and the space between ball housing 111 and magnet 119 are narrowed, thereby realizing a compact image stabilization device 100.

[0051] Here, the three ball receiving surfaces (107a, 109a, and 111a) provided on the movable part 101 require high durability because the ball 131 rolls repeatedly on them. Furthermore, because the movable part 101 is supported in the optical axis direction by the ball 131, the ball receiving surfaces may be subjected to strong forces due to impact from a drop or vibration, so the ball receiving surfaces require high hardness. Therefore, in conventional image stabilization devices, ceramics such as zirconia or silicon nitride are used for the ball 131, and the ball receiving surfaces are made of a metal material to ensure durability and hardness. Furthermore, the ball receiving surfaces of conventional image stabilization devices have been made of magnetic metal plates due to considerations of surface hardness and cost.

[0052] However, in the case of the image stabilization device 100 of the present invention, in which the space between the ball housing portion 111 and the magnet 117b and between the ball housing portion 111 and the magnet 119 are narrowed to achieve miniaturization, if a magnetic metal plate is used for the ball receiving surface 111a, the ball housing portion 111 will be attracted by the magnetic force of the magnet 117b or the magnet 119 (see F in FIG. 8; FIG. 8 illustrates the case where the ball receiving surface 111a is attracted to the magnet 117b or the magnet 119). Specifically, when the voice coil motors 113, 115, and 117 are not driven, the ball receiving surface 111a is attracted to the magnet 117b or the magnet 119. As a result, the movable portion 101 becomes stuck to the magnet 117b or the magnet 119, and the image sensor 16 mounted on the movable portion 101 becomes tilted. The movable portion 101 can be observed when the photographing lens device 12 is removed from the image pickup device body 2, and therefore, if the image pickup element 16 is held in an inclined position, it is not desirable from an external appearance point of view.

[0053] Furthermore, when the voice coil motor is driven, the thrust of the voice coil motor keeps the movable part 101, which mounts the image sensor 16, in a centered state. When the magnet and the ball receiving surface in the image stabilization device 100 are sufficiently far apart, the force of attraction of the magnet to the ball receiving surface is negligibly small and does not pose a problem. However, when the magnet and the ball receiving surface are close to each other, a force acts on the movable part 101, constantly pulling it away from the center. Therefore, when the ball receiving surface is subjected to an attractive force from the magnet, a counter force must be applied to the attractive force to keep the movable part 101 in the center, which increases the power consumption of the voice coil motor.

[0054] In recent years, heat dissipation from electronic devices, including the image sensor 16, has often become an issue in efforts to reduce their size, and from this perspective, there is also a need to suppress the current flowing through the coil of the voice coil motor.

[0055] In this embodiment, in consideration of the above-mentioned circumstances, the ball receiving surface 111a of the image stabilization device 100 is made of a non-magnetic metal material. As a result, in the image stabilization device 100 of the present invention, the ball receiving surface 111a is not attracted to a magnet, and even when the voice coil motor is not driven, the movable part 101 does not stick to the magnet, which would spoil the appearance. Furthermore, when the ball receiving surface 111a is made of a magnetic material, the imaging device 10 equipped with the image stabilization device 100 can control the movable part 101 without applying a resistance force to the magnetic force received from the magnet, thereby reducing power consumption in the voice coil motor.

[0056] Next, the selection of the material for the ball receiving surface 111a in the image stabilization device 100 of the present invention will be described.

[0057] FIG. 9 is a diagram illustrating the load P applied by the ball 131 to the ball receiving surface 111a.

[0058] When selecting a material for the ball receiving surface 111a, it is necessary to design it under conditions that prevent the concentrated load of the ball 131 from causing dents on the ball receiving surface 111a, as will be described below.

[0059] That is, the yield stress (σ y ) must be greater than the concentrated load Pmax (σ y (Yield stress)>Pmax) Pmax is calculated by the following formula (1), P0 of Pmax is calculated by the following formula (2), and a of P0 is calculated by the following formula (3).

[0060]

[0061]

[0062]

[0063] The following values ​​are used in the above equations (1) to (3). In addition, in the above equation (3), v1, E1, and R1 represent the respective values ​​of the ball 131, and v2, E2, and R2 represent the respective values ​​of the ball receiving surface 111a. In this example, the ball receiving surface 111a is a flat surface, so R2 = ∞.

[0064]

[0065] The surface of the ball receiving surface 111a that comes into contact with the ball 131 needs to be smooth (surface roughness Ra of 0.4 μm or less). This is because if there are any irregularities such as dents on the ball receiving surface 111a, fluctuations in the driving force occur when the ball 131 passes, making drive control difficult.

[0066] On the other hand, from the above-described formulas (1) to (3), it is possible to reduce the stress on the ball receiving surface 111a by increasing the radius of the ball 131, thereby suppressing the occurrence of dents on the ball receiving surface 111a. However, increasing the radius of the ball 131 is not advisable because it directly leads to an increase in the size of the image stabilization device 100.

[0067] If the hardness of both the ball receiving surface 111a and the ball 131 can be increased, it is possible to prevent the occurrence of dents on the ball receiving surface 111a while maintaining the radius of the ball 131.

[0068] Therefore, it is preferable that the surface hardness of the ball receiving surface 111a is HV 300 or more. It is also preferable that the surface roughness Ra of the ball receiving surface 111a is 0.4 μm or less.

[0069] 10 is a diagram showing the Vickers hardness (HV) of materials that can be used for the ball receiving surface 111 a. Fig. 10 shows the surface hardness of "material code A5052 (aluminum alloy)," "material code SPCC (Steel Plate Cold Commercial) (cold-rolled steel plate)," "material code SUS (Steel Use Stainless) 304 (stainless steel)," "high manganese stainless steel (denoted as High MnSUS in the figure)," "material code SUS (Steel Use Stainless) 301CSP SEH," and "ceramics (alumina 99%)."

[0070] As shown in Figure 10, non-magnetic materials such as SUS304 and A5052 have a hardness lower than HV300 and are not sufficiently hard for use as materials for the ball receiving surface 111a. On the other hand, ceramics are non-magnetic and exhibit high hardness, making them suitable as materials for the ball receiving surface 111a. However, it is difficult to process ceramics into a smooth surface for use as the ball receiving surface 111a, which increases the cost of the part.

[0071] Therefore, high manganese stainless steel (high MnSUS) is preferably used for the ball receiving surface 111a in this embodiment. By using high manganese stainless steel, which is a non-magnetic material, for the ball receiving surface 111a, it is possible to provide a reliable vibration reduction device 100 in which the ball receiving portion 111 is prevented from being attracted to the magnet 117b or 119 and the occurrence of dents on the ball receiving surface 111a is suppressed. Furthermore, because high manganese stainless steel is corrosion-resistant without the need for surface treatment, surface treatment such as coating or plating is not necessary, and durability can be guaranteed by the strength of the base material.

[0072] As explained above, by making ball receiving surface 111a of image stabilization device 100 of the present invention a non-magnetic material, ball receiving surface 111a will not be attracted to a magnet, allowing for maintaining a favorable appearance and reducing the power required for the voice coil motor. Note that although the above explanation has been directed to ball receiving surface 111a of ball housing portion 111, similar non-magnetic materials can also be used for the ball receiving surfaces (ball receiving surface 107a and ball receiving surface 109a) of the other ball housing portions (ball housing portion 107 and ball housing portion 109).

[0073] <Damper Member> Next, the damper member 151 of the ball receiving portion 111 will be described.

[0074] FIG. 11 is an enlarged view of the vicinity of the damper member 151 provided in the ball receiving portion 111 of the movable portion 101 (area V in FIG. 6).

[0075] The damper member 151 is made of an elastic material such as rubber. The damper member 151 is provided in a ring-shaped state wrapped around the outer circumferential side surface of the hollow protrusion of the ball accommodating portion 111. When the movable portion 101 moves, the ball accommodating portion 111 collides with the magnet 117b or the magnet 119 that is disposed nearby. Therefore, in order to mitigate the impact of this collision, the damper member 151 is provided on the outer circumferential side surface of the hollow protrusion of the ball accommodating portion 111.

[0076] The movable unit 101 can move freely in the X-Y plane, and can therefore rotate around an axis parallel to the optical axis L. The rotation of the movable unit 101 is restricted by shafts 133 and 135, which function as movable end stoppers. However, the outermost periphery of the movable unit 101 can move over a larger range than the range of translational movement within the X-Y plane. Therefore, adjacent components of the image stabilization device 100 provided inside the imaging device body 2 must be located farther away from the optical axis L to avoid interference with the movable unit 101, which can result in an increase in the size of the imaging device body 2.

[0077] Therefore, in this embodiment, the damper member 151 is caused to collide with the magnet 117b or the magnet 119, thereby restricting the rotation of the movable part 101.

[0078] 12 and 13 are diagrams illustrating the movement of the movable part 101 restricted by the damper member 151. Fig. 12 is a diagram illustrating the case where the movable part 101 is located at the center position, and Fig. 13 is a diagram illustrating the restriction of the rotational movement of the movable part 101 by the damper member 151.

[0079] 12 , the distance LS1 from the optical axis center OL to the shaft 133 is shorter than the distance LD from the optical axis center OL to the ball receiving portion 111. Furthermore, the distance LS2 from the optical axis center OL to the shaft 135 is shorter than the distance LD from the optical axis center OL to the ball receiving portion 111. In other words, the damper member 151 is disposed further outward from the optical axis center OL than the shaft 133 and the shaft 135.

[0080] In FIG. 13 , reference numeral 101A indicates the position of the movable part 101 after translation in the negative X-axis direction, and reference numeral 101B indicates the position of the movable part 101 after rotation counterclockwise in the drawing. When the movable part 101 translates in the negative X-axis direction, shaft 133 or shaft 135 functions as a movement restricting member, restricting the movement of the movable part 101. On the other hand, when the movable part 101 rotates counterclockwise, the damper member 151 collides with the magnet 119 before the shafts 133 and 135 function as movement restricting members, restricting the rotation of the movable part 101. Therefore, by restricting the rotation of the movable part 101 by causing the damper member 151 to collide with the magnet 119, the amount of movement during rotation can be restricted without reducing the movement stroke in the translation direction of the movable part 101. In the above description, the case where damper member 151 collides with magnet 119 when movable part 101 rotates counterclockwise has been described, but the rotation of movable part 101 is similarly restricted by damper member 151 when movable part 101 rotates clockwise. In this case, damper member 151 collides with magnet 117b, thereby restricting the rotation of movable part 101.

[0081] 14 is a diagram showing a cross section of the ball receiving portion 111 and the damper member 151. In FIG. 14, a cross section of the portion indicated by W in FIG. 11 is shown.

[0082] Reference numeral 181 denotes a modified example of the ball accommodating portion 111. Because the damper member 151 is repeatedly subjected to force due to collisions with the magnets 117b and 119, it is preferable to provide a protrusion 155 having an outer diameter larger than the inner diameter of the damper member 151 to prevent the damper member 151 from falling off the ball accommodating portion 111. This makes it possible to prevent the damper member 151 from falling off the ball accommodating portion 111.

[0083] Reference numerals 183 and 185 indicate modified examples of the damper member 151. The cross section of the damper member 151 may be rectangular as shown in the example of reference numeral 181, or may be round as shown in the example of reference numeral 183. The cross section of the damper member 151 may also be triangular as shown in the example of reference numeral 185.

[0084] In the above description, the damper member 151 is provided on the outer peripheral side surface of the ball accommodating portion 111, but the present invention is not limited to this example. For example, the damper member 151 may be provided in the ball accommodating portion 107 or the ball accommodating portion 109.

[0085] <Magnet Holding Structure> Next, a structure for holding the magnet 119 in the second yoke 105 will be described.

[0086] As described above, the magnet 119 has the function of restricting movement of the movable part 101 by colliding with the damper member 151. Therefore, upon collision, a force parallel to the direction of movement of the movable part 101 is applied from the damper member 151. This force becomes large when the camera is subjected to an impact, such as when dropped, so fixing the magnet 119 to the second yoke 105 with adhesive is often insufficient. Therefore, in the image stabilization device 100 of this embodiment, a contact portion is provided on the second yoke 105 that contacts the side surface of the magnet 119, thereby preventing the magnet 119 from shifting due to the impact force from the damper member 151.

[0087] FIG. 15 is a diagram illustrating the contact portion provided on the second yoke 105. As shown in FIG.

[0088] 15 shows an example in which the second yoke 105 is provided with a contact portion 161a of the convex portion 161. By forming a part of the second yoke 105 as the convex portion 161, the contact portion 161a that contacts the side surface of the magnet 119 is formed. The convex portion 161 is provided on the side of the magnet 119 opposite the side on which the damper member 151 is located, so as to sandwich the magnet 119 together with the damper member 151. The convex portion 161 forms a convex shape on the magnet 119 side (in the positive X direction in the figure) of the contact surface S between the bottom surface of the magnet 119 and the second yoke 105.

[0089] In this way, by forming a convex portion 161 on the second yoke 105 and providing an abutment portion 161a, the magnet 119 can be held in place even if the movable portion 101 moves, the damper member 151 collides with the magnet 119, and an impact force is applied to the magnet 119.

[0090] FIG. 16 is a diagram illustrating another example of the contact portion provided on the second yoke 105. In FIG.

[0091] 16 shows an example in which abutment portion 163a of recessed portion 163 is provided in second yoke 105. By forming a part of second yoke 105 as recessed portion 163, abutment portion 163a that abuts against the side surface of magnet 119 is formed. In this way, by forming recessed portion 163 in part of second yoke 105 and providing abutment portion 163a, magnet 119 can be held appropriately.

[0092] FIG. 17 is a diagram illustrating another example of the contact portion.

[0093] 17, a hole 173 is provided in a member 171 separate from the second yoke 105, and a contact portion 171a is formed on the side surface of the hole 173. The second yoke 105 and the member 171 are connected so as not to move relative to each other. The member 171 is preferably made of a material with a lower magnetic permeability than the second yoke 105. In this way, the magnet 119 can be held appropriately by providing the hole 173 in a member 171 separate from the second yoke 105 and using the side surface of the hole 173 as the contact portion 171a.

[0094] The above example has been described with respect to holding the magnet 119, but is not limited to this. The above-described holding mechanism can also be employed for the other magnets held by the image stabilization device 100 (the magnet 113b, the magnet 115b, and the magnet 117b).

[0095] FIG. 18 is a diagram illustrating an example in which a shaft (shaft member) 125 is provided on the upper surface of the convex portion 161 described in FIG.

[0096] The convex portion 161, which forms the contact portion 161a for holding the magnet 119, needs to be positioned on the opposite side of the magnet 119 from the damper member 151. Therefore, there are limitations on where the convex portion 161 can be positioned. Furthermore, to increase the thrust of the voice coil motor, opposing yokes (first yoke 103) must be positioned at the positions facing the magnet 113b across the coil 113a, the magnet 115b across the coil 115a, and the magnet 117b across the coil 117a. A shaft 125 must be positioned to connect the opposing yoke (first yoke 103) to the second yoke 105. The shaft 125 is fixed to the second yoke 105 by screw fastening or caulking. By providing the fixing position for the shaft 125 on the upper surface of the convex portion 161, space can be saved compared to when a separate fixing position for the shaft 125 is provided. In this case, the distance from the attachment position of the shaft 125 to the first yoke 103 is shortened by the height of the convex portion 161. Therefore, by designing the shaft 125 to be shorter than the other shafts (shaft 121 and shaft 123), the first yoke 103 and the second yoke 105 are attached in parallel.

[0097] Although examples of the present invention have been described above, it goes without saying that the present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the present invention.

[0098] REFERENCE SIGNS LIST 1: Subject 2: Imaging device body 10: Imaging device 12: Photographing lens device 16: Imaging element 40: Control unit 58: Driving unit 100: Image stabilization device 101: Movable part 102: Fixed part 103: First yoke 105: Second yoke 107: Ball accommodating part 109: Ball accommodating part 111: Ball accommodating part 121: Shaft 123: Shaft 125: Shaft 131: Ball 133: Shaft 135: Shaft 141: Movable end restricting opening 143: Movable end restricting opening 151: Damper member

Claims

1. An image blur correction device comprising: an imaging element; a plurality of coils; a movable part supported so as to be movable within a plane parallel to the imaging plane of the imaging element; a fixed part that supports the movable part, the fixed part having a plurality of magnets and yokes arranged to face the plurality of coils; balls sandwiched between the movable part and the fixed part; wherein the movable part has a ball housing part constituted by a hollow protruding part that houses the balls, and a ball receiving surface provided at the bottom of the ball housing part is made of a non-magnetic metal material; the image blur correction device, wherein an elastic member is provided on an outer peripheral side surface of the hollow protruding part of the ball housing part.

2. An image blur correction device comprising: an imaging element; a plurality of coils; a movable part supported so as to be movable within a plane parallel to the imaging plane of the imaging element; a fixed part that supports the movable part, the fixed part having a plurality of magnets and yokes arranged to face the plurality of coils; balls sandwiched between the movable part and the fixed part; wherein the movable part has a ball housing part constituted by a hollow protruding part that houses the balls, and a ball receiving surface provided at the bottom of the ball housing part is made of a non-magnetic metal material; the fixed part is constituted by a first yoke and a second yoke provided at a distance from the first yoke; the movable part is arranged between the first yoke and the second yoke; the plurality of magnets are provided on the second yoke; the ball housing part is provided on the second yoke side of the movable part; the second yoke is provided with a contact part that contacts at least one side surface of the plurality of magnets; the contact part is constituted by a convex side surface of the second yoke. The image blur correction device.

3. The fixed part is constituted by a first yoke and a second yoke provided at a distance from the first yoke; the movable part is arranged between the first yoke and the second yoke; the plurality of magnets are provided on the second yoke; The image blur correction device according to claim 1, wherein the ball housing part is provided on the second yoke side of the movable part.

4. The image blur correction device according to claim 2 or 3, wherein the ball housing part is provided on the movable part so as to face the second yoke.

5. The image blur correction device according to claim 1 or 2, wherein the ball housing part is arranged between the plurality of magnets.

6. The image blur correction device according to claim 2, wherein the ball housing portion is provided with an elastic member on an outer peripheral side surface of the hollow protruding portion.

7. The image blur correction device according to claim 3, wherein the second yoke is provided with a contact portion that contacts at least one side surface of the plurality of magnets.

8. The first yoke and the second yoke are connected via a shaft member. The contact portion is constituted by a convex side surface of the second yoke. The shaft member is provided on the convex upper surface. The image blur correction device according to claim 7.

9. The first yoke and the second yoke are connected via a shaft member. The shaft member is provided on the convex upper surface. The image blur correction device according to claim 2.

10. The image blur correction device according to claim 1 or 2, wherein the ball receiving surface has a surface hardness of HV300 or more.

11. The image blur correction device according to claim 1 or 2, wherein the ball receiving surface has a surface roughness Ra of 0.4 μm or less.

12. An imaging device including the image blur correction device according to claim 1 or 2.

13. Comprising a processor. The processor. The imaging device according to claim 12, wherein the movement of the movable portion is controlled by a drive mechanism constituted by some or all of the plurality of coils and the plurality of magnets, and when the ball receiving surface is made of a magnetic material, the control is performed without applying a resistance to the magnetic force received from at least one of the plurality of magnets.