JP2009294613A - Imaging-element drive device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging-element drive device able to ensure the stability of an imaging surface and obtain a satisfactory photographic image. <P>SOLUTION: The imaging-element drive device 300 includes: a first frame member 302 and a second frame member 301. The second frame member 301 is configured such that rolling members 307x, 336x are disposed at the vertices of a quadrilateral D surrounding an optical axis within a plane intersecting the optical axis O at right angles. The second frame member 301 includes the imaging element 31 which is moved so as to intersect the optical axis at right angles relative to the first frame member via the rolling members and which is disposed such that the imaging surface intersects the optical axis at right angles. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image sensor driving device, and more particularly to an image sensor driving device that corrects image blur by independently displacing an image sensor in a horizontal direction and a vertical direction in a plane orthogonal to an optical axis of a photographing optical system. is there.

  2. Description of the Related Art In recent years, imaging apparatuses such as so-called digital cameras that photoelectrically convert an optical image formed by a photographing optical system using an imaging element or the like and record an image signal obtained thereby are recorded widely.

  Among conventional image pickup apparatuses, in particular, a digital camera or the like is usually used mainly by photographing with a user holding it by hand, so-called hand-held photographing. As described above, when a photographing operation is performed in a state where the posture of the imaging apparatus is unstable, an image obtained as a result of the photographing may be unclear due to image blurring.

  Therefore, various types of image pickup apparatuses having an image blur correction function for correcting such image blur to obtain a clear image have been proposed and put into practical use.

  As a technique for realizing an image blur correction function employed in a conventional imaging device such as a digital camera (hereinafter simply referred to as a camera), for example, blur vibration in the camera pitch direction (direction around the X axis) An imaging optical system that detects camera shake vibration in the yaw direction (direction around the Y axis) using a shake detection unit such as an angular velocity sensor and cancels the generated shake signal based on the detected shake signal. Or an image pickup surface of the image pickup device by independently shifting the image pickup device in the horizontal direction and the vertical direction in a plane orthogonal to the optical axis of the imaging optical system, that is, a plane parallel to the image plane of the image pickup device. What corrects the above-mentioned image blur is known.

  For example, the techniques disclosed in Japanese Patent Application Laid-Open Nos. 2007-29884, 2008-48220, and the like displace the image sensor independently in the horizontal and vertical directions within a plane orthogonal to the optical axis of the photographing optical system. This is an image sensor driving device that corrects the image blur.

  In these conventional image sensor driving devices, a fixed frame that is fixed to a camera or the like and serves as a basic component member, a first moving frame that is arranged to be movable in the horizontal direction with respect to the fixed frame, and the first moving frame And a second moving frame that holds and mounts the image sensor, and is configured to drive the first moving frame and the second moving frame independently of each other. Yes.

  In this case, positioning of each frame in the optical axis direction is performed by bringing adjacent frames into contact with each other using a biasing member. In addition, structural measures such as interposing a member for reducing contact resistance are provided between the frames so that the relative movement of the frames is always performed smoothly. Yes.

  On the other hand, an image pickup element in a normal camera or the like is usually arranged in a plane whose image plane is always orthogonal to the optical axis of the photographing optical system.

  In the conventional image sensor driving apparatus configured as described above, the movement of the first movement frame relative to the fixed frame and the movement of the second movement frame relative to the first movement frame are within the plane parallel to the image plane of the image sensor. In the horizontal direction and the vertical direction, it is performed independently.

As described above, in the image pickup device driving apparatus, the frame member on which the image pickup device on which the subject image is formed is moved in a plane parallel to the image plane. The stability of the image plane of the image sensor with respect to the optical axis is required.
JP 2007-29884 A JP 2008-48220 A

  In other words, in the conventional image sensor driving apparatus having the above-described configuration, when each moving frame is moved in a plane parallel to the image plane of the image sensor (that is, in a plane orthogonal to the optical axis), the movement of each frame is performed. If it is not performed smoothly, for example, abnormal noise occurs or the image plane of the image sensor mounted on the moving frame becomes unstable.

  As described above, in a state where the stability of the image plane of the image sensor is not ensured, a location where the optical path length varies depending on the location on the image plane. As a result, there arises a problem that the acquired image becomes unclear.

  The present invention has been made in view of the above-described points, and an object of the present invention is to drive an image sensor that can ensure the stability of the image plane of the image sensor and acquire a high-quality captured image. Is to provide a device.

  In order to achieve the above object, in the imaging device driving device according to the present invention, a rolling member is disposed at each of the first frame member and the vertex of a quadrangle that includes the optical axis in a plane orthogonal to the optical axis. A second frame including an image sensor that is moved relative to the first frame member in a direction orthogonal to the optical axis via the rolling member and is arranged so that the imaging surface is orthogonal to the optical axis. And a member.

  ADVANTAGE OF THE INVENTION According to this invention, the image pick-up element drive device which can ensure the stability of the image surface of an image pick-up element and can acquire a quality picked-up image can be provided.

  The present invention will be described below with reference to illustrated embodiments.

  Note that an image sensor driving apparatus according to an embodiment shown below is for performing camera shake correction of an image pickup unit including an image sensor that obtains an image signal by photoelectric conversion. In the following embodiments, a single-lens reflex digital camera with an interchangeable photographic lens will be described as an application example as an example of an imaging device equipped with the imaging element driving device of the present invention.

First, an outline of a system configuration of a digital camera that internally includes an image sensor driving device according to an embodiment of the present invention will be described with reference to FIG.
FIG. 1 is a schematic block configuration diagram mainly showing an electrical system configuration in a digital camera equipped with the image sensor driving apparatus of the present embodiment.

  A digital camera (hereinafter simply abbreviated as “camera”) provided with an image sensor driving apparatus according to the present embodiment is configured by a body unit 100 as a camera body and a lens unit 10 as an interchangeable lens.

  The lens unit 10 is detachable via a lens mount 10a provided on the front surface of the body unit 100. The lens unit 10 is controlled by its own lens control microcomputer (hereinafter referred to as Lμcom) 5. On the other hand, the body unit 100 is controlled by a body control microcomputer (hereinafter referred to as “Bμcom”) 50. These Lμcom5 and Bμcom50 are electrically connected via the communication connector 6 in a state where the lens unit 10 is mounted on the body unit 100. As a camera system, Lμcom5 is configured to operate while being dependent on Bμcom50.

  The lens unit 10 includes the above-described Lμcom 5, the photographing lens 1, the lens driving mechanism 2, the diaphragm 3, and the diaphragm driving mechanism 4. The taking lens 1 is driven by a DC motor (not shown) provided in the lens driving mechanism 2 while being held by the lens frame 1a. Thereby, the photographing lens 1 and the lens frame 1a are moved forward and backward in the direction along the optical axis O. The diaphragm 3 is driven by a stepping motor (not shown) provided in the diaphragm driving mechanism 4. Lμcom5 controls each of these motors based on the command of Bμcom50.

  In the body unit 100, the following components are arranged as shown in the figure. For example, as an observation optical system, a single-lens reflex type constituent member including a quick return mirror 11, a sub mirror 11 a, a screen 12 a, a pentaprism 12, an eyepiece lens 13, and the like, and a focal plane type member disposed on the photographing optical axis (O). A shutter 15 and an AF sensor unit 16 for receiving a reflected light beam from the sub mirror 11a and detecting a defocus amount are provided.

  Further, in the body unit 100, an AF sensor driving circuit 17 for driving and controlling the AF sensor unit 16, a mirror driving circuit 18 for driving and controlling the quick return mirror 11, and a spring for driving the front curtain and the rear curtain of the shutter 15. A shutter charge mechanism 19 for charging the shutter, a shutter control circuit 20 for controlling the movement of the front and rear curtains, a photometric sensor 21a for detecting the light flux from the pentaprism 12, and photometry based on the output of the photometric sensor 21a A photometric circuit 21 for processing is provided. Further, a strobe 371 whose light emission is controlled by a strobe control circuit 372 is provided.

  On the photographic optical axis (O), an imaging unit 30 is provided that is disposed behind the above-described observation optical system and receives and subjects the subject image formed by the photographic lens 1 to photoelectric conversion. The image pickup unit 30 is a unit in which a CCD 31 as an image pickup element, an optical low-pass filter (LPF) 32 and a dustproof filter 33 arranged on the front surface thereof are integrated. A piezoelectric element 34 is attached to the peripheral edge of the dustproof filter 33. The piezoelectric element 34 has two electrodes, and the dust-proof filter 33 is vibrated at a predetermined frequency by the dust-proof filter control circuit 48 to vibrate the dust-proof filter 33, and the dust adhered to the filter surface is removed by this vibration. It is configured to be able to. The image pickup unit 30 is configured by adding an image stabilization unit 300 for camera shake correction which is an image pickup element driving device of the present embodiment. The details of the configuration of the image stabilization unit 300 for camera shake correction will be described later.

  In addition, the camera system including the image pickup device driving apparatus according to the present embodiment performs image processing using the CCD interface circuit 23 connected to the CCD 31, the liquid crystal monitor 24, the SDRAM 25 functioning as a storage area, the FLASH ROM 26, and the like. And an electronic recording display function as well as an electronic imaging function. Here, the recording medium 27 is an external recording medium such as various memory cards or an external HDD. The recording medium 27 is communicable with the body unit 100 via a communication connector and is detachable from the body unit 100 so as to be exchangeable. The recording medium 27 records image data obtained by photographing. The other storage area is a memory for storing predetermined control parameters necessary for camera control. For example, a nonvolatile memory 29 made of an EEPROM is provided so as to be accessible from the Bμcom 50.

  The Bμcom 50 is provided with an operation display LCD 51 and an operation display LED 51a for notifying the user of the operation state of the camera by display output, and a camera operation switch group (hereinafter, the switch is described as SW) 52. ing. The camera operation SW group 52 is a switch group including operation buttons necessary for operating the camera, such as a release SW, a mode change SW, and a power SW. Further, a battery 54 as a power source and a power supply circuit 53 that converts and supplies the voltage of the battery 54 to a voltage required by each circuit unit constituting the camera system are provided. The power supply circuit 53 includes a voltage detection circuit that detects a voltage change when current is supplied from an external power supply via a jack.

  Each part of the camera system configured as described above generally operates as follows.

  First, the image processing controller 28 takes in image data from the CCD 31 by controlling the CCD interface circuit 23 in accordance with a command of Bμcom 50. This image data is converted into a video signal by the image processing controller 28 and output and displayed on the liquid crystal monitor 24. The user can check the captured image from the display image on the liquid crystal monitor 24.

  The SDRAM 25 is a memory for temporarily storing image data, and is used as a work area when image data is converted. The image data is stored in the recording medium 27 after being converted into JPEG data.

  The mirror drive mechanism 18 is a mechanism for driving the quick return mirror 11 to the up position and the down position. When the quick return mirror 11 is in the down position, the light flux from the photographing lens 1 is on the AF sensor unit 16 side. The light is divided and guided to the pentaprism 12 side. The output from the AF sensor in the AF sensor unit 16 is transmitted to the Bμcom 50 via the AF sensor driving circuit 17 and a known distance measurement process is performed. On the other hand, a part of the light beam that has passed through the pentaprism 12 is guided to a photometric sensor 21a in the photometric circuit 21, and a known photometric process is performed based on the amount of light detected here.

  Next, the configuration of the imaging unit 30 including the CCD 31 will be described with reference to FIG.

  FIG. 2 is a vertical side view showing the configuration of the imaging unit 30 provided in the camera shown in FIG.

  The imaging unit 30 is disposed on the side of the photoelectric conversion surface of the CCD 31 and the CCD 31 as an imaging device that obtains an image signal corresponding to the light irradiated on the photoelectric conversion surface after passing through the imaging optical system. An optical low-pass filter (LPF) 32 that removes a high-frequency component from a subject light beam that is transmitted through the filter, a dust-proof filter 33 that is opposed to the optical LPF 32 at a predetermined interval on the front side, and a periphery of the dust-proof filter 33 And a piezoelectric element 34 which is disposed in the part and applies predetermined vibration to the dustproof filter 33.

  Here, the CCD chip 31 a of the CCD 31 is directly mounted on the flexible substrate 31 b disposed on the fixed plate 35. Connection portions 31c and 31d extend from both ends of the flexible substrate 31b. The connection portions 31 c and 31 b are connected to connectors 36 a and 36 b provided on the main circuit board 36. Thus, the CCD 31 is electrically connected to the main circuit board 36 via the flexible board 31b and the connectors 36a and 36b. The protective glass 31e of the CCD 31 is fixed on the flexible substrate 31b via a spacer 31f.

  A filter receiving member 37 made of an elastic member or the like is disposed between the CCD 31 and the optical LPF 32. The filter receiving member 37 is disposed at a position that avoids the effective range of the photoelectric conversion surface at the front edge of the CCD 31 and abuts in the vicinity of the rear edge of the optical LPF 32 so that the CCD 31 and the optical LPF 32 are in contact with each other. It is comprised so that the airtightness between may be kept substantially. A Y frame 38 is disposed so as to hermetically cover the CCD 31 and the optical LPF 32. The Y frame 38 has a rectangular opening 38a at a substantially central portion around the photographing optical axis (O). A stepped portion 38b having a substantially L-shaped cross section is formed on the inner peripheral edge of the opening 38a on the dustproof filter 33 side. The optical LPF 32 and the CCD 31 are disposed from the rear side of the opening 38a.

  Here, the position of the optical LPF 32 in the direction along the photographing optical axis (O) is regulated by the step portion 38b by placing the front side peripheral portion of the optical LPF 32 in contact with the step portion 38b so as to be airtight. In addition, a retaining structure is provided from the inside of the Y frame 38 toward the front side.

  On the other hand, at the peripheral edge of the front side of the Y frame 38, a dustproof filter receiver that protrudes to the front side of the step 38b around the step 38b in order to hold the dust filter 33 on the front of the optical LPF 32 at a predetermined interval. The part 38c is formed over the entire circumference.

  The dustproof filter 33 formed in a circular or polygonal plate shape as a whole is formed by an elastic body such as a leaf spring, and the dustproof filter is pressed by a pressing member 40 fixed to the dustproof filter receiving portion 38c with a screw 39. It is supported by the receiving portion 38c. Here, the annular seal 41 is interposed between the piezoelectric element 34 portion disposed on the outer peripheral edge of the dustproof filter 33 on the back side and the dustproof filter receiving portion 38c to ensure an airtight state. . The imaging unit 30 includes the Y frame 38 formed in such a size that the CCD 31 can be mounted in this manner, and the peripheral portion of the CCD 31 is configured in an airtight structure.

  Next, a detailed configuration of the image stabilization unit 300 for camera shake correction that is the image sensor driving device of the present embodiment will be described below.

  3 and 4 are exploded perspective views showing the configuration of the image sensor driving apparatus (anti-shake unit for camera shake correction) according to this embodiment. 3 is a perspective view seen from the front side of the image sensor driving device (anti-shake unit for camera shake correction), and FIG. 4 is a perspective view of the image sensor driving device (anti-shake unit for camera shake correction). It is the perspective view seen from the back side. FIG. 5 is a front view of the image sensor driving device (anti-shake unit for camera shake correction). 6 is a partial cross-sectional view taken along line [6]-[6] in FIG. FIG. 7 is a partial cross-sectional view taken along line [7]-[7] in FIG.

  As shown in FIG. 3, an image stabilization unit for camera shake correction (hereinafter simply abbreviated as an image stabilization unit) 300, which is an image sensor driving device of the present embodiment, provided in the camera, has a photographing optical axis (O). The X-axis direction (first direction) and the Y-axis are in a plane including the X-axis and the Y-axis orthogonal to the photographing optical axis (O) and are orthogonal to each other. A camera shake correction function for correcting image blur is realized by displacing and moving the image sensor (CCD 31) in each direction (second direction).

  The anti-vibration unit 300 includes, as a drive source, a vibrator that generates elliptical vibration in the drive unit when a predetermined frequency voltage is applied. Further, the image stabilization unit 300 uses the Y frame 38 on which the CCD 31 is mounted among the constituent members of the imaging unit 30 as the final moving object, in the X-axis direction (first direction) and the Y-axis direction (second direction). In each direction).

  First, the image stabilization unit 300 of the present embodiment surrounds a Y frame 38 on which an imaging unit 30 including an optical LPF 32, a dustproof filter 33, a CCD 31 and the like is mounted, and a frame opening 301a formed around the photographing optical axis (O). An X frame 301 having a frame shape having a frame portion 301b and mounting the Y frame 38 so as to be movable in the Y-axis direction, and a frame shape having a frame portion 302b surrounding an opening 302a formed around the photographing optical axis (O). The X frame 301 is mounted so as to be movable in the X-axis direction and is fixed to a fixing portion (not shown in FIG. 3) of the body unit 100. The X frame 301 is fixed to the fixed frame 302 in the X-axis direction. An X-axis drive mechanism portion 310x that is displaced in the Y-axis direction, and a Y-axis drive mechanism portion 310y that moves the Y frame 38 in the Y-axis direction relative to the X frame 301.

  Note that, as shown in FIG. 3, the X-axis direction and the Y-axis direction are directions perpendicular to each other and perpendicular to the photographing optical axis (O). The X axis represents the camera left-right direction, and the Y axis represents the camera up-down direction.

  The X frame 301 is a holding member relative to the Y frame 38. The fixed frame 302 is a fixing member and a holding member for the X frame 301.

  Therefore, the Y frame 38 is displaced in the Y axis direction with respect to the X frame 301 by the Y axis drive mechanism 310y. As a result, the CCD 31 mounted on the Y frame 38 is displaced so as to compensate for blurring in the Y-axis direction within an XY plane parallel to the image plane.

  Further, the X frame 301 is displaced in the X axis direction with respect to the fixed frame 302 together with the Y frame 38 by the X axis drive mechanism portion 310x. As a result, the CCD 31 mounted on the Y frame 38 is displaced so as to compensate for blurring in the X-axis direction within an XY plane parallel to the image plane.

  The X-axis drive mechanism section 310x includes an X-axis vibrator (first vibrator) 320x, and a sliding body (first moving body section) 330x that is integrally fixed to the X frame 301 and is to be driven together with the X frame 301. And a pressing mechanism (biasing means) 340x for urging the X-axis vibrator 320x toward the sliding body 330x.

  The X-axis vibrator 320x includes a rectangular piezoelectric body 323x and driving elements (driving units) 321x and 322x, and the driving elements (driving units) 321x and 322x are provided on one surface of the piezoelectric body 323x. When a predetermined frequency voltage is applied to the rectangular piezoelectric body 323x, elliptical vibrations are generated in the driver elements (drive units) 321x and 322x.

  Although not shown in FIG. 3, the X-axis vibrator 320x is provided with a vibrator holder at a central position on the side opposite to the driver elements 321x and 322x of the piezoelectric body 323x. The protrusion formed on the child holder fits into the groove-shaped holding portion 342x (first holding portion) of the fixed frame 302, whereby the X-axis vibrator 320x is restricted from moving in the X-axis direction, and the fixed frame 302 Is positioned against. In this state, the X-axis vibrator 320x is housed in an X-axis vibrator housing part 302c formed on the outer edge side of the frame part 302b of the fixed frame 302. The X-axis vibrator 320x is pressed toward the back side of the sliding body 330x by a pressing plate (pressing member) 341x of a pressing mechanism 340x described later.

  With such a configuration, a driving force due to elliptical vibration generated in the driver elements 321x and 322x acts on the sliding body 330x in the X-axis direction.

  The sliding body 330x is formed by fixing a sliding plate (sliding portion) 332x on a bearing (guided portion) 331x. The bearing 331x is fixed to a part of the X frame 301 so as to be integrated with the X frame 301 by, for example, a screw 333x. At this time, the driver elements 321x and 322x of the X-axis vibrator 320x are pressed from behind by the pressing mechanism 340x as described above, and the sliding plate 332x is disposed at a position in contact with the bearing 331x.

  Note that the fixing of the sliding body 330x to the X frame 301 is not limited to screwing, but may be bonding or the like, and the fixing method is not particularly limited.

  As shown in FIG. 3, the sliding body 330x is formed in a size smaller than that of the X frame 301, and is formed in a size corresponding to, for example, the X-axis vibrator 320x. Further, the X frame 301 is formed of a resin material with low rigidity, aluminum, or the like, whereas the sliding plate 332x is formed of a material such as ceramic having high wear resistance and high rigidity. . The bearing 331x is formed of a material that has been hardened to a hardenable material such as ferritic stainless steel and has increased rigidity.

  A V-groove 334x having an opening toward the front surface and extending in the direction along the X-axis is formed in the bearing 331x of the sliding body 330x. At a portion facing the V-groove 334x, a wear-preventing V-groove plate 306x having a V-groove 305x extending in the direction along the X axis is provided. Between the V groove plate 306x and the bearing 331x, two balls 336x (rolling elements) positioned by a retainer 335x formed in a plate shape by a material such as plastic are sandwiched.

  The two balls 336x are positioned by a retainer 335x in the vicinity of a position slightly outside the X-axis direction from directly below the driver elements 321x and 322x, and movement in the X-axis direction is restricted. The rolling element is not limited to the ball 336x, and a roller or the like may be applied.

  A bearing (guide portion) 304x is disposed on the front side of the V-groove plate 306x. The bearing 304x is fixed to a predetermined fixing portion of the X-axis vibrator housing portion 302c of the fixed frame 302 with a screw 303x.

  As described above, the two balls 336x arranged in a line along the X-axis direction are sandwiched between the V-groove 305x and the V-groove 334x, so that the bearing 304x fixed to the fixed frame 302 and the X frame The bearing 331x fixed to 301 has a structure that can move relatively smoothly in the X-axis direction.

  The pressing mechanism 340x includes a pressing plate 341x that holds the X-axis vibrator 320x, and a pressing spring 347x that biases the pressing plate 341x.

  One end of the pressing plate 341x is fixed to the fixed frame 302 by a screw 344x via a seat plate and a spacer. The other end of the pressing plate 341x is fixed to the fixed frame 302 by a screw 345x via a seat plate, a spacer, and the pressing spring 347x.

  The urging force of the pressing spring 347x presses the X-axis vibrator 320x toward the back side of the sliding body 330x via the pressing plate 341x, so that the driver elements 321x and 322x press the sliding plate 332x with a predetermined force. It comes to contact. The pressing force of the pressing mechanism 340x is set to a very large force of about 15N (Newton).

  With the configuration as described above, the bearing 331x can rotate around an axis passing through the center of the ball 336x and parallel to the V-groove 334x. However, the bearing 331x is integrated with the X frame 301, and the bearing 331x is fixed on a position away from the bearing 331x in a direction different from the X axis direction, specifically, on the frame portion 302b of the fixed frame 302. Two balls (rolling elements) 307x are disposed at substantially both ends on one side opposite to the other side.

  The two balls 307x are disposed so as to be sandwiched between the fixed frame 302 and the X frame 301. Two long holes 302d are formed in the fixed frame 302, and two long holes 301d are formed in the X frame 301 at each portion facing each of the long holes 302d. The depth dimension of each of the long holes 302d and 301d is set to be smaller than the radius of the ball 307x. Further, the width dimension in the Y-axis direction of each of the long holes 302d and 301d is set to be approximately equal to or slightly larger than the diameter of the ball 307x. The width dimension in the X-axis direction of each of the long holes 302d and 301d is set according to the amount of movement when the X frame 301 is moved with respect to the fixed frame 302 by rolling the ball 307x.

  Further, two elastic springs 308 x are suspended between the fixed frame 302 and the X frame 301. The two springs 308x include a spring mounting portion formed in the vicinity of the two balls 307x, that is, two spring mounting portions 302f of the fixed frame 302, and two spring mounting portions 301f of the X frame 301. Are respectively locked. Therefore, these two springs 308x urge the fixed frame 302 and the X frame 301 in the direction of pulling each other. Thereby, both the frames 302 and 301 are not separated.

  At this time, each of the two balls 307x is stored and held in the two long holes 302d and 301d one by one. With this configuration, the X frame 301 is positioned in the direction along the optical axis O of the X frame 301 with respect to the fixed frame 302, that is, in the Z-axis direction, so that the distance between both frames is maintained.

  Note that the urging force of the spring 308x only needs to maintain the holding state of the ball 307x, and is set weaker than the urging force of the pressing spring 347x of the pressing mechanism 340x.

  Therefore, when the fixed frame 302 and the X frame 301 are combined via the two balls 307x, and two springs 308x are suspended between the frames 302 and 301 in a predetermined position, In the frames 302 and 301, the surfaces of the frame portions 302b and 301b facing each other are not in contact with each other, and a slight gap is generated between them.

  Thus, the fixed frame 302 and the X frame 301 have a structure that can relatively smoothly move in the X-axis direction via the two balls 307x.

  The fixed frame 302, the X frame 301, and the ball 307x are all formed of a metal member. Therefore, when the X frame 301 moves relative to the fixed frame 302, wear, noise, or the like occurs if the wall surface in each of the long holes 302d and 301d and the ball 307x (that is, metals) are in direct contact with each other. there is a possibility.

  Therefore, a plate-like sheet 309x made of a material such as plastic is interposed between each ball 307x and each wall surface (long hole bottom surface) in each of the long holes 302d and 301d of both frames 302 and 301. As a result, the X frame 301 moves smoothly with respect to the fixed frame 302, and generation of wear, abnormal noise, or the like is suppressed during the movement.

  With the configuration as described above, the X frame 301 to which the sliding body 330x is integrally attached has two balls 336x provided on one side and two pieces provided on the other side opposite to the fixed frame 302. It is configured to be able to move in the X direction with four-point support by the ball 307x.

  Note that the ball 307x and the ball 336x are disposed on opposite sides of the optical axis O and the frame openings 302a and 301a. As a result, the distance between the ball 307x and the ball 336x is arranged as far as possible, which contributes to stabilization of the movement of the X frame 301 in the X-axis direction.

  Furthermore, according to the above configuration, the movement of the X frame 301 in the X-axis direction is guided by the four balls (rolling elements) 307x and 336x, and at the same time, the movement in a direction other than the X-axis direction is restricted. Yes. Therefore, stable driving of the X frame 301 in the X-axis direction can be ensured.

  In the image sensor driving apparatus (anti-vibration unit 300) of the present embodiment, the four balls 307x and 336x are quadrilaterals that include the optical axis O in a plane orthogonal to the optical axis O, for example, in the imaging plane ( It is configured to be arranged at each of the vertices in FIG. The X frame 301 moves relative to the fixed frame 302 in the direction orthogonal to the optical axis O via the four balls 307x and 336x. The X frame 301 is mounted with a Y frame 38 on which an image pickup unit 30 including an image pickup device (CCD 31) arranged so that the image pickup surface is orthogonal to the optical axis O is mounted. Therefore, the Y frame 38 on which the imaging unit 30 is mounted can be moved relative to the fixed frame 302 in the X axis direction together with the X frame 301, and relative to the X frame 301 in the Y axis direction, as will be described later. It is movable.

  On the other hand, the basic structure of the Y-axis drive mechanism 310y is substantially the same as that of the above-described X-axis drive mechanism 310x. That is, the Y-axis drive mechanism unit 310y uses the X frame 301 as a relative fixing member instead of the fixed frame 302, and uses the Y frame 38 (second moving body) as a moving object instead of the X frame 301. The Y-axis drive mechanism 310y is fixed integrally with the Y-frame 38 and driven by the Y-frame 38 (second oscillator) 320y (not shown; provided in the X-frame). A target sliding body (second moving body portion) 330y and a pressing mechanism (biasing means) 340y that biases the Y-axis vibrator 320y toward the sliding body 330y are provided.

  The Y-axis drive mechanism 310y will be described only with respect to the parts different from the X-axis drive mechanism 310x, and the same or corresponding components as those of the X-axis drive mechanism 310x will be described with reference to the X-axis drive mechanism. The same reference numerals as those of the components of the section 310x are used, and the subscript is indicated by y, and the detailed description thereof is omitted.

  The difference between the Y-axis drive mechanism 310y and the X-axis drive mechanism 310x is the thickness of the sliding plates 332x and 332y (the materials are the same and the density is the same). Here, the plate thickness of the X-axis drive mechanism portion 310x is configured to be thicker than that of the Y-axis drive mechanism portion 310y. Therefore, the rigidity of the sliding plate 332x with respect to the bending (that is, the bending corresponding to the bending vibration of the vibrator) increases in proportion to the cube of the thickness, and the sliding body configured by fixing the sliding plate 332y. The rigidity of 330y is smaller than that of the sliding body 330x. Here, the sliding plate 332x of the X-axis drive mechanism 310x is thickened, but this is because the X frame 301 driven by the X-axis drive mechanism 310x also holds the Y-axis drive mechanism 310y. This is because a large driving force needs to be generated, and the vibration amplitude of the X-axis vibrator 320x is larger, so that the rigidity is increased and vibration energy loss due to bending due to application of vibration to the sliding plate 332x is reduced. Further, by increasing the thickness of the sliding plate 332x, it is possible to increase the rigidity of the sliding body 330x, and by increasing the bending fundamental frequency of the sliding body 330x, the sliding body 330x becomes the X-axis vibrator. It can set so that it may not overlap with a drive frequency, and the loss of the vibration energy by resonance of sliding body 330x can also be controlled.

  Note that, as described above, the sliding members 330x and 330y including the sliding plates 332x and 332y have different thicknesses than the sliding members 330x and 330y. The same effect can be obtained by increasing the fundamental frequency of bending on the sliding body 330x side by, for example, applying materials having different densities.

  Further, the positioning in the direction along the optical axis O of the Y frame 38 with respect to the X frame 301 (Z axis direction) and the distance between both the frames 301 and 38 are one length perforated in the frame portion 301b of the X frame 301. One ball 307y accommodated in the hole 301d and a spring 308y suspended between the spring hook portions 301g and 38g of both frames 301 and 38 are defined and maintained.

  On the other hand, as shown in FIG. 1, the image stabilization unit 300 according to the present embodiment includes an X-axis gyro 350 x that is a sensor that detects a blur around the X-axis of the body unit 100 (pitch in the pitch direction), and the body unit 100. It has a Y-axis gyro 350y that is a sensor for detecting a blur around the Y-axis (blur in the yaw direction). These X-axis gyro 350x and Y-axis gyro 350y are not shown in FIG. 3, but are fixed to predetermined portions of the main body of the body unit 100.

  The vibration isolation unit 300 is a position detection sensor including a hall element 351 disposed on the fixed frame 302 and a magnet 352 disposed on a portion of the Y frame 38 facing the hall element 351. 353.

  The details of the position detection sensor 353 as the position detection device will be described. The hall element 351 is provided on one surface orthogonal to the optical axis of the box-shaped housing, and the magnet 352 extends from a part of the Y frame 38. It is attached to the shaped portion so as to face the Hall element 351 and to be relatively movable in the inside of the casing.

  Then, based on the signals from the X-axis gyro 350x, the Y-axis gyro 350y and the position detection sensor 353, the image stabilization control circuit 355 for controlling the vibrator drive circuit 354 for the X-axis vibrator 320x and the Y-axis vibrator 320y (FIG. 1). The image stabilization control circuit 355 is configured to perform a control operation in accordance with an instruction from the Bμcom 50.

  In the image stabilization unit 300 (imaging element driving device) according to the embodiment having the above-described configuration, the fixed frame 302 (first frame member) and X that moves relative to the fixed frame 302 in the X-axis direction. A frame 301 (second frame member), a Y frame 38 that moves relative to the X frame 301 in the Y-axis direction, and four balls 307x and 336x (rolling members) are configured. . In this case, the four balls 307x and 336x are located between the fixed frame 302 and the X frame 301 and are orthogonal to the optical axis O (for example, in a plane parallel to the imaging surface of the imaging device (CCD 31)). A configuration is adopted in which each of the vertices of the quadrilateral including the optical axis O is arranged. As a result, the X frame 301 moves relative to the fixed frame 302 in a relatively stable state in the direction orthogonal to the optical axis O via the four balls 307x and 336x.

  Further, the X frame 301 has a form in which a Y frame 38 on which an imaging unit 30 including an imaging element (CCD 31) arranged so that the imaging surface is orthogonal to the optical axis O is mounted. As a result, the Y frame 38 on which the imaging unit 30 is mounted can move relative to the fixed frame 302 in the X axis direction together with the X frame 301, and can move relative to the X frame 301 in the Y axis direction. .

  As described above, the quadrilateral formed by the four balls 307x and 336x has a plurality of balls (rolling members) arranged on at least one side, and is along the optical axis O in the quadrilateral region. An imaging surface is present on the direction projection surface.

  Further, a plurality of balls 307 x (rolling members) are sandwiched between the fixed frame 302 and the X frame 301 by two springs 308 x (spring members) spanned between the fixed frame 302 and the X frame 301. It is composed.

  With such a configuration, according to the image stabilization unit 300 of the above-described embodiment, the X frame 301 can always be held movably in a stable state with respect to the fixed frame 302. Accordingly, by driving the image stabilization unit 300 and moving the X frame 301 and the Y frame 38, respectively, the imaging unit 30 mounted on the Y frame 38 mounted on the X frame 301 is moved in a direction along the imaging surface. In this case, the imaging surface of the CCD 31 (imaging device) can always be kept stable with respect to the optical axis O, and the amount of change in the optical path length can be suppressed. Therefore, even when the image stabilization unit 300 is driven, it is possible to always obtain a good quality captured image while suppressing image blur.

[Example]
FIG. 8 shows a measurement result of the change amount (mm) of the optical path length with respect to the drive amount (mm) when the image stabilization unit 300 of the present embodiment configured as described above is operated.

  In FIG. 8, the polygonal line plotted with the symbol A (“◯”; white circle) is the measurement result by the image stabilization unit 300 of the present embodiment. In addition, the broken line plotted with the symbol B (“●”; black circle) is the measurement result by the vibration isolating unit of the conventional form.

  In this case, the form of the conventional vibration isolating unit is substantially the same as that of the vibration isolating unit of the present embodiment, but as a rolling element to be sandwiched between the fixed frame 302 and the X frame 301. For example, in the vicinity of the sliding body 330x, two balls 336x are disposed in the vicinity of the sliding body 330x, while the ball 307x disposed on the opposite side of the sliding body 330x is configured with only one ball. The anti-vibration unit is taken as an example of a conventional form.

  As is clear from the graph of FIG. 8, in the image stabilization unit 300 of this embodiment, when the drive amount in the X-axis direction is driven within a range of ± 0.8 mm, the optical path length change amount compared to the conventional product. Has been achieved. Therefore, according to the configuration of the present embodiment, the amount of change in the optical path length when the image sensor driving device (anti-vibration unit) is driven can be suppressed, and a more stable image surface can be secured. It turns out that.

  In the above-described embodiment, by devising the arrangement of the four balls 307x and 336x sandwiched between the fixed frame 302 and the X frame 301, the X frame 301 is placed in the X-axis direction with respect to the fixed frame 302. In addition to this, in addition to this, focusing on the relationship with the Y frame 38 that moves in the Y-axis direction with respect to the X frame 301, the four balls are A similar arrangement is also possible. In this case, a substantially similar configuration can be realized if the fixed frame 302 in the above-described embodiment is replaced with the X frame 301 and the X frame 301 is replaced with the Y frame.

  In addition, the present invention is not limited to the above-described embodiment, and it is needless to say that various modifications and applications can be implemented without departing from the spirit of the invention. Further, the above embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if some constituent elements are deleted from all the constituent elements shown in the embodiment, the problem described in the column of the problem to be solved by the invention can be solved, and the effect described in the effect of the invention Can be obtained as an invention.

1 is a schematic block configuration diagram mainly showing an electrical system configuration in a digital camera equipped with an image sensor driving device of the present embodiment. FIG. 2 is a longitudinal side view illustrating a configuration of an imaging unit of the camera in FIG. 1. The exploded perspective view which looked at the composition of the image sensor drive device of this embodiment from the front side. FIG. 3 is an exploded perspective view of the configuration of the image sensor driving device of the present embodiment as viewed from the back side. The front view of the image sensor drive device of this embodiment. The fragmentary sectional view which follows the [6]-[6] line of FIG. The fragmentary sectional view which follows the [7]-[7] line | wire of FIG. The Example which shows the measurement result of the variation | change_quantity (mm) of the optical path length with respect to the drive amount (mm) at the time of operating the image pick-up element drive device of this embodiment.

Explanation of symbols

1 …… Photo lens 5 …… Lens control microcomputer (Lμcom)
10 …… Lens unit 30 …… Imaging unit 30 Frame 30
31 …… CCD
32 …… Optical low-pass filter (LPF)
33 …… Dustproof filter 34 …… Piezoelectric element 38 …… Y frame 38a …… Opening 38g …… Spring hook 40 …… Pressing member 48 …… Dustproof filter control circuit 50 …… Body control microcomputer (Bμcom)
100 …… Body unit 300 …… Anti-shake unit for camera shake correction 301 …… X frame 301a …… Frame opening 301b …… Frame portion 301d …… Elongated hole 301f …… Spring hook portion 301g …… Spring hook portion 302 …… Fixed frame 302a …… Frame opening 302b …… Frame portion 302c …… X-axis vibrator housing portion 302d …… Elongated hole 302f …… Spring bridge portion 305x …… V groove 306x …… V groove plates 307x, 307y, 336x …… Balls 308x, 308y ... Spring 309x ... Plate-like sheet 310x ... X-axis drive mechanism 310y ... Y-axis drive mechanism 320x ... X-axis vibrator 320y ... Y-axis vibrator 321x, 322x ... Driver 323x …… Piezoelectric bodies 330x, 330y …… Sliding bodies 332x, 332y …… Sliding plates 334x …… V-groove 335x …… Retainer 340x …… Pressing mechanism 341x… Press plate 342x ... groove-shaped holding portion 347x ... press spring 350x ... X-axis gyro 350y ... Y-axis gyro 351 ... Hall element 352 ... magnet 353 ... position detection sensor 354 ... vibrator drive circuit 355 ... ... Anti-vibration control circuit

Claims (4)

In the image sensor driving device,
A first frame member;
A rolling member is disposed at each of the vertices of the quadrilateral including the optical axis in a plane orthogonal to the optical axis, and relative to the first frame member in a direction orthogonal to the optical axis via the rolling member. A second frame member including an image sensor that is moved so that an imaging surface is orthogonal to the optical axis;
An image sensor driving device comprising:   The image sensor driving apparatus according to claim 1, wherein a plurality of the rolling members are arranged on at least one side of the quadrilateral.   2. The image sensor driving apparatus according to claim 1, wherein an imaging surface is present on a projection surface in an optical axis direction within the quadrilateral region.   A state in which the plurality of rolling members are sandwiched between the first frame member and the second frame member by a spring member spanned between the first frame member and the second frame member The image pickup device driving apparatus according to claim 1, wherein the image pickup element driving device is held by

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