JP2008172995A - Drive unit and imaging device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact drive unit with high driving force and high efficiency. <P>SOLUTION: An X-axis vibrator 320x which generates elliptical vibration is used as a drive source. At a side of a mobile body 311x, block construction is formed by an X frame 301 formed into a desired size as a moving object, and a sliding body 330x which is smaller than the X frame 301, by which both of these are fixed and made integral, then a sliding plate 332x and a bearing 331x are provided at the smaller sliding body 330x, whichby a driving force transmitting function from the X-axis vibrator 320x and a moving direction guiding function are put together. The larger X frame 301 is constituted so that it may be integrated with the sliding body 330x, and may simply perform follow-up movement, and it is formed that rigidity becomes higher only at a side of the smaller sliding body 330x, by which the high efficiency of driving force transmission is attained. Not so higher rigidity is required at a side of the X frame 301 as the side of the sliding body 330x, and the desired size is formed with a lightweight material. Moreover, a dedicated guide mechanism to regulate a moving direction of the X frame 301 is not required. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a driving device that drives a moving body using elliptical vibration of a vibrator and moves the moving body in a predetermined direction, and an imaging device such as a digital camera that performs shake correction by the driving device.

  2. Description of the Related Art Conventionally, for example, there is a camera as an imaging apparatus having a blur correction function. As a camera shake correction function provided in the camera, a camera shake vibration in the camera pitch direction and camera shake vibration in the camera yaw direction are detected using a shake detection means such as an angular velocity sensor, and the shake is canceled in a direction based on the detected shake signal. Camera shake correction that corrects image blur on the imaging surface of the imaging device by shifting a part of the imaging optical system or the imaging device independently in the horizontal and vertical directions in a plane perpendicular to the imaging optical axis. The function is known.

  In a camera shake correction mechanism that realizes such a camera shake correction function, in order to correct camera shake, a part of the photographing lens or the image sensor itself is horizontally and vertically within a plane perpendicular to the photographing optical axis. Driving means moving in the direction are used. This drive means is required to have high responsiveness, precision drive (micro drive), and self-holding ability to hold the position of the moving body even when the power is turned off in order to operate following camera shake.

  In response to such a requirement, Patent Document 1 discloses a camera shake correction mechanism using an impact actuator. Patent Document 2 discloses a vibration wave linear motor that linearly drives a shaft relative to the vibrator by pressing two vibrators that generate elliptical vibrations on the surface against the shaft. In this drive mechanism using a vibration wave linear motor, a cylindrical shaft is relatively moved by a vibrator, a lens frame is driven by a protrusion provided on the shaft, and the lens frame is moved in a moving direction by a guide mechanism provided for the lens frame. Is configured to move while being guided.

JP 2005-331549 A JP 2006-67712 A

  However, in the camera shake correction mechanism using the impact actuator shown in Patent Document 1 as a drive mechanism, high responsiveness, precision drive, and self-holding ability can be obtained. There is a problem that a high output cannot be obtained. For example, in a camera or the like, when a dustproof filter or the like is integrated on the front surface of an image pickup device such as a CCD, and a relatively large and heavy image pickup unit is driven, it is not suitable. In order to increase the driving force, it is necessary to increase the inertial mass, and the driving mechanism itself becomes large. Further, from the principle of driving by inertial force that overcomes frictional force, energy loss due to frictional sliding always occurs, and there is a fundamental problem that efficiency cannot be increased very much.

  On the other hand, a so-called vibration wave motor using elliptical vibration of a vibrator has high efficiency, easily obtains a large driving force, and can be said to be suitable for driving a relatively large and heavy imaging unit or the like. However, in order to generate a large driving force, it is necessary to press the vibrator against the moving body with a large force. If the rigidity of the moving body is low, the vibrator is bent by the pressing force (the vibration amplitude of the vibration wave motor is (Because it is originally a small size of several μm, even a deflection of about several μm causes a problem.) The efficiency of the driving mechanism is reduced, and in extreme cases, the driving force is absorbed and the system does not operate. To do. In order to prevent such a problem, as shown in Patent Document 2, a cylindrical shaft, which is a moving body that is in direct contact with the vibrator, is formed so as to have high rigidity, and is actually moved. The lens frame has a configuration in which a driving force is transmitted through a projection to be moved. In such a configuration, a driving force transmission mechanism for the lens frame side, a guide mechanism for the lens frame side, and the like are separately required, and there is a problem that the mechanism becomes complicated and becomes large and heavy. In this respect, the moving object itself such as a lens frame may be configured to have high rigidity and may be directly driven by the elliptical vibration of the vibrator, but has a specific resonance frequency determined by the shape, material, etc. In order to avoid problems such as the occurrence of inherent vibrations when driving force is transmitted by elliptical vibration from the vibrator, it is necessary to increase the size and weight more than necessary, which is contrary to the demand for size reduction.

  The present invention has been made in view of the above, and it is an object of the present invention to provide a highly efficient driving device and imaging device that are small in size and large in driving force.

  In order to solve the above-described problems and achieve the object, a drive device according to the present invention includes a vibrator that generates elliptical vibration in a drive unit when a predetermined frequency voltage is applied, and a holder that holds the vibrator. A fixed member having a portion, and a moving body that is driven by the elliptical vibration of the vibrator and moves relative to the fixed member. And a guided portion that is provided on a side opposite to the sliding portion and engages with a guide portion of the fixing member to guide a movement direction, and has higher rigidity than the first moving body portion. And a second moving body portion formed smaller than the first moving body portion and fixed to the first moving body portion.

  In the drive device according to the present invention, in the above invention, the first moving body portion that moves integrally with the second moving body portion includes the guide portion of the fixed member and the second moving body portion. The moving direction is guided by the engagement with the guided portion.

  In the drive device according to the present invention as set forth in the invention described above, the first moving body portion is formed of a resin material, aluminum, or magnesium.

  Further, in the above invention, the drive device according to the present invention is configured so that the drive unit is pressed against the sliding unit from the side opposite to the guide unit across the second moving body unit and the vibrator. An urging means for urging the vibrator is provided.

  In the drive device according to the present invention, in the above invention, the guide portion and the guided portion have rolling elements arranged in a line along the movement direction, and the movement direction from the guide portion is One rolling element for positioning is provided between the first moving body part and the fixed member at a position separated in a different direction in a sandwiched state by an urging force.

  The drive device according to the present invention includes a first vibrator that generates elliptical vibration in the drive unit when a predetermined frequency voltage is applied, and a first holding unit that holds the first vibrator. The fixed member and the drive unit of the first vibrator are pressed, and the moving direction is restricted in the first direction by the guide part of the fixed member, and is driven by the elliptical vibration of the first vibrator. The first moving body that moves in the first direction with respect to the fixed member and the first moving body that has the second holding portion are applied with a predetermined frequency voltage. A second vibrator that generates elliptical vibration in the drive section, and a second section that is different from the first direction by the guide section of the first moving body that is pressed by the drive section of the second vibrator. The direction of movement is regulated by the direction of the elliptical vibration of the second vibrator A second moving body that is moved and moves in a second direction with respect to the first moving body, wherein at least one of the first and second moving bodies is a desired one. A first moving body portion formed in a size, a sliding portion in contact with the driving portion, and provided on a side opposite to the sliding portion and engaged with the guide portion to guide the moving direction. A second movement that has a higher rigidity than the first moving body portion and is smaller than the first moving body portion and is fixed to the first moving body portion. It consists of a body part.

  The image pickup apparatus according to the present invention includes a microcomputer that controls the operation of the entire image pickup apparatus, and shakes the image pickup element in the first direction and the second direction orthogonal to each other in a plane orthogonal to the photographing optical axis. In the imaging device that is displaced so as to compensate, the first vibrator that generates elliptical vibration in the drive unit when a predetermined frequency voltage is applied based on an instruction from the microcomputer, and the first vibrator are held A fixing member fixed to the imaging apparatus main body, the driving portion of the first vibrator being pressed, and a guide portion included in the fixing member in a first direction. A first moving body that is driven by the elliptical vibration of the first vibrator and moves in the first direction with respect to the fixed member; and the first holding unit that has a second holding portion. Held by the moving body A second vibrator that generates elliptical vibration in the drive section when a predetermined frequency voltage is applied based on an instruction from the microcomputer, and the drive section of the second vibrator is pressed, and The moving direction is regulated in the second direction by the guide portion of the first moving body, and is driven by the elliptical vibration of the second vibrator to move in the second direction with respect to the first moving body. A second moving body that holds the image sensor on the photographing optical axis, and at least one of the first and second moving bodies is formed in a desired size. 1 moving body portion, a sliding portion with which the driving portion contacts, and a guided portion which is provided on the side opposite to the sliding portion and engages with the guide portion to guide the moving direction. The first moving body part is more rigid than the first moving body part. It formed small in characterized by comprising a second mobile part fixed to the mobile part of the first.

  The image pickup apparatus according to the present invention includes a microcomputer that controls the operation of the entire image pickup apparatus, and shakes the image pickup element in the first direction and the second direction orthogonal to each other in a plane orthogonal to the photographing optical axis. In an imaging apparatus that is displaced so as to compensate, a first vibrator that generates elliptical vibration in a drive unit when a predetermined frequency voltage is applied based on an instruction from the microcomputer, and an opening around an imaging optical axis A first member that is formed in a frame shape and has a first holding portion that holds the first vibrator, and is fixed in a desired shape with a fixing member fixed to the imaging apparatus main body and a frame shape that surrounds an opening around the imaging optical axis. A first movable body portion formed in a size; a sliding portion in which the driving portion of the first vibrator is pressed and brought into contact; and the fixed member provided on a side opposite to the sliding portion Engaging with the guide part And a guided portion whose movement direction is guided in the direction of the first moving body portion, which is higher in rigidity than the first moving body portion and smaller than the first moving body portion. The first movement having a second holding body and a second moving body fixed to the first vibrator and driven by the elliptical vibration of the first vibrator to move in the first direction with respect to the fixing member A second vibrator that is held in the body and generates elliptical vibration in the drive unit when a predetermined frequency voltage is applied based on an instruction from the microcomputer; and the imaging element is held on the photographing optical axis. A third moving body portion formed in a desired size and disposed in the opening of the first moving body portion, and a sliding portion in contact with the driving portion of the second vibrator being pressed. And a guide portion provided on the side opposite to the sliding portion and included in the first moving body portion. And a guided portion whose movement direction is guided in the second direction, and is higher in rigidity than the third moving body portion and smaller than the third moving body portion. And a fourth moving body portion that is driven by elliptical vibration of the second vibrator and moves in the second direction with respect to the first moving body portion. It is characterized by.

  According to the driving device and the imaging device according to the present invention, the vibrator that generates elliptical vibration that is highly efficient and easily obtains a large driving force is used as a driving source, while the moving body side is formed to a desired size as a moving object. The first moving body part and the second moving body part smaller than the first moving body part are fixed and integrated with each other, and a large force is applied to the smaller second moving body part. By providing the sliding portion to be added and the guided portion, the driving force transmission function from the vibrator and the moving direction guide function are integrated, and the larger first moving body portion is integrated with the second moving body portion. Thus, it is configured to simply follow and move, and only the smaller second moving body portion side is formed to have high rigidity, so that the drive force transmission can be made highly efficient. The moving body side is lighter and does not require higher rigidity than the second moving body side It only needs to be formed to the desired size using a material, and does not require a dedicated guide mechanism for restricting the moving direction of the first moving body part. As a whole, it has a large driving force and is highly efficient, compact and lightweight. There is an effect that it can be realized.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, a best mode for carrying out a driving device and an imaging device according to the invention will be described with reference to the drawings. The imaging apparatus according to the present embodiment is equipped with a driving device for performing camera shake correction of an imaging unit including an imaging element that obtains an image signal by photoelectric conversion. An application example to a flex-type electronic camera (digital camera) will be described. The present invention is not limited to the embodiment, and various modifications can be made without departing from the spirit of the present invention.

  First, a system configuration example of the camera according to the present embodiment will be described with reference to FIG. FIG. 1 is a block diagram schematically showing mainly an electrical system configuration of the camera of the present embodiment. The camera according to the present embodiment is configured by a system including a body unit 100 as a camera body and a lens unit 10 as an interchangeable lens that is one of accessory devices.

  The lens unit 10 is detachable through a lens mount (not shown) 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 “Lucom”) 5. The body unit 100 is controlled by a body control microcomputer (hereinafter referred to as “Bucom”) 50. These Lucom 5 and Bucom 50 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, the Lucom 5 is configured to operate in cooperation with the Bucom 50 in a dependent manner.

  The lens unit 10 includes a photographing lens 1 and a diaphragm 3. The taking lens 1 is driven by a DC motor (not shown) provided in the lens driving mechanism 2. The diaphragm 3 is driven by a stepping motor (not shown) provided in the diaphragm mechanism 4. Lucom 5 controls each of these motors based on a command from Bucom 50.

  In the body unit 100, the following components are arranged as shown in the figure. For example, a single-lens reflex component (penta prism 12, quick return mirror 11, eyepiece lens 13, submirror 11a) as an optical system, a focal plane shutter 15 on the photographing optical axis, and a reflected light beam from the submirror 11a In response, an AF sensor unit 16 for detecting the defocus amount is provided. The AF sensor unit 16 is based on a phase difference detection method, and includes a single lens 16a, a reflection mirror 16b, and an AF sensor 16c such as a CCD.

  In addition, an AF sensor driving circuit 17 for driving and controlling the AF sensor unit 16, a mirror driving mechanism 18 for driving and controlling the quick return mirror 11, and a shutter charging mechanism 19 for charging a spring for driving the front curtain and the rear curtain of the shutter 15. A shutter control circuit 20 that controls the movement of the front and rear curtains, and a photometric circuit 21 that performs photometric processing based on a photometric sensor 21a that detects the light flux from the pentaprism 12 are provided.

  An imaging unit 30 for photoelectrically converting a subject image that has passed through the optical system is provided on the photographing optical axis. The image pickup unit 30 is formed by integrating a CCD 31 that is an image pickup element, an optical low-pass filter (LPF) 32 and a dustproof filter 33 disposed on the front surface thereof as a unit. A piezoelectric element 34 is attached to the periphery of the dust filter 33. The piezoelectric element 34 has two electrodes, and the dust-proof filter 33 is vibrated by vibrating the piezoelectric element 34 at a predetermined frequency by the dust-proof filter control circuit 48 to remove dust attached to the filter surface. Configured to get. An anti-vibration unit for camera shake correction, which will be described later, is added to the imaging unit 30.

  The camera system of the present embodiment also includes a CCD interface circuit 23 connected to the CCD 31, a liquid crystal monitor 24, an SDRAM 25 that functions as a storage area, a flash ROM 26, and an image processing controller 28 that performs image processing. The electronic recording display function can be provided together with the electronic imaging function. Here, the recording medium 27 is an external recording medium such as various memory cards or an external HDD, and is mounted so as to be communicable with the camera body via a communication connector and exchangeable. Then, image data obtained by photographing is recorded on the recording medium 27. As the other storage area, a non-volatile memory 29 made of, for example, an EEPROM for storing predetermined control parameters necessary for camera control is provided so as to be accessible from the Bucom 50.

  The Bucom 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 SW52. The camera operation SW 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. Furthermore, a battery 54 as a power source and a power 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, and current is supplied from an external power source via a jack. A voltage detection circuit for detecting a voltage change when supplied is also provided.

  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 an instruction from the Bucom 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 confirm 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 Bucom 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 imaging unit 30 including the CCD 31 will be described with reference to FIG. FIG. 2 is a longitudinal side view illustrating a configuration example of the imaging unit 30. The imaging unit 30 is disposed on the side of the photoelectric conversion surface of the CCD 31 and a CCD 31 as an imaging device that obtains an image signal corresponding to the light that is transmitted through the imaging optical system and irradiated on its own photoelectric conversion surface. 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 31a of the CCD 31 is directly mounted on the flexible substrate 31b disposed on the fixed plate 35, and connectors 31c and 31d extending from both ends of the flexible substrate 31b are provided on the main circuit board 36. It is connected to the main circuit board 36 side through 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 peripheral edge of the front surface of the CCD 31, and is in contact with the vicinity of the peripheral edge of the optical LPF 32 so that the CCD 31 and the optical LPF 32 It is comprised so that substantially airtightness may be maintained between. A holder 38 that covers the CCD 31 and the optical LPF 32 in an airtight manner is disposed. The holder 38 has a rectangular opening 38a at a substantially central portion around the photographing optical axis, and a step 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 optical LPF 32 is positioned so that the front side peripheral edge of the optical LPF 32 is in substantially airtight contact with the stepped portion 38b, whereby the position of the optical LPF 32 in the photographing optical axis direction is regulated by the stepped portion 38b. The front side is secured from the inside.

  On the other hand, a dust-proof filter receiving portion that protrudes to the front side of the step portion 38b around the step portion 38b in order to hold the dust-proof filter 33 on the front surface of the optical LPF 32 at a predetermined interval at the peripheral portion on the front side of the holder 38. 38c is formed over the entire circumference. The dustproof filter 33 formed in a circular or polygonal plate shape as a whole is formed of an elastic body such as a leaf spring and is pressed by a pressing member 40 fixed to the dustproof filter receiving portion 38c with a screw 39. It is supported by the part 38c. Here, an annular seal 41 is interposed between the piezoelectric element 34 portion disposed on the outer peripheral edge portion on the back side of the dustproof filter 33 and the dustproof filter receiving portion 38c, thereby ensuring an airtight state. The imaging unit 30 is configured in an airtight structure including the holder 38 formed in a desired size for mounting the CCD 31 in this way.

  Next, the camera shake correction function of the camera according to the present embodiment will be described. In the present embodiment, when the direction of the photographing optical axis is the Z-axis direction, the X-axis direction that is the first direction orthogonal to the XY plane orthogonal to the photographing optical axis and the Y-axis direction that is the second direction. The image pickup device CCD 31 is displaced and moved so as to compensate for the shake, and the image stabilization unit including the shake correction drive device applies an elliptical vibration to the drive unit when a predetermined frequency voltage is applied. The generated vibrator is used as a drive source, and the holder 38 on which the CCD 31 in the imaging unit 30 is mounted is configured as a moving object.

  First, an operation principle of a vibrator used as a drive source in the drive device of the present embodiment will be described. FIG. 3 is a schematic diagram showing the operation principle of the vibrator. The vibrator 200 includes a piezoelectric body 201 formed in a rectangular shape with a predetermined size, a pair of drive electrodes 202 and 203 formed in a centrally symmetrical manner by polarization while being biased toward one side of the piezoelectric body 201, and a drive Drive elements 204 and 205 as drive units provided at the surface positions of the piezoelectric body 201 corresponding to the electrodes 202 and 203 are provided. When a positive voltage is applied to the drive electrode 202, as shown in FIG. 3A, the drive electrode 202 portion of the polarization structure is deformed to extend, while the piezoelectric body 201 portion on the back side thereof is not deformed to extend. Therefore, it deforms into an arc shape as a whole. On the contrary, when a minus voltage is applied to the drive electrode 202, the drive electrode 202 portion of the polarization structure is deformed so as to shrink as shown in FIG. 3C, while the piezoelectric body 201 portion on the back side thereof is not shrunk. As a whole, it is deformed into an arcuate shape opposite to that shown in FIG. The same applies to the drive electrode 203 side.

  Therefore, in order to generate elliptical vibrations on the surfaces of the driver elements 204 and 205, a frequency voltage based on a sine wave having a predetermined frequency is applied to one of the polarized drive electrodes 202 of the piezoelectric body 201 and to the other drive electrode 203. A frequency voltage by a sine wave having a phase shift at the same frequency as the frequency voltage applied to the drive electrode 202 is applied. The frequency of the applied frequency voltage is such that the center of the piezoelectric body 201 is a bending vibration node, the driver elements 204 and 205 are antinodes of bending vibration, and the longitudinal vibration node of the piezoelectric body 201 coincides with the bending vibration node. It is set to a predetermined numerical value. Then, the vibrator 200 repeats the bending vibration shown in FIGS. 3A to 3C including the restored state shown in FIG. Elliptical vibrations are generated on the surfaces of the children 204 and 205. Therefore, by placing the movable body to be driven on the driver elements 204 and 205 side of the vibrator 200 while being in pressure contact with each other, the movable body moves according to the direction of the elliptical vibration generated on the surfaces of the driver elements 204 and 205. It becomes.

  At this time, by changing the phase difference of the frequency voltage applied to the drive electrodes 202 and 203, it is possible to change the shape of the elliptical vibration generated on the surfaces of the drive elements 204 and 205, thereby driving the vibrator 200. Thus, the moving speed of the moving moving body can be changed. For example, if the phase difference of the frequency voltage is 0 °, the speed is 0. However, if the phase difference is increased, the speed gradually increases, the maximum speed is reached when the phase difference is 90 °, and the phase difference is increased beyond 90 °. Then, on the contrary, the speed gradually decreases, and when the phase difference is 180 °, the speed becomes zero again. When the phase difference is set to a negative value, the rotational direction of the elliptical vibration generated in the driver elements 204 and 205 is reversed, and the moving body can be driven in the reverse direction. Also in this case, the maximum speed is obtained when the phase difference is −90 °.

  Next, the vibration isolating unit according to the present embodiment using such a vibrator as a drive source will be described with reference to FIGS. FIG. 4 is an exploded perspective view showing a configuration example of the image stabilization unit of the present embodiment, and FIG. 5 is a schematic side view of the image stabilization unit showing a simplified shape of each part shown in FIG. 6 is a schematic side view showing the X-axis drive mechanism in FIG. 5 extracted and enlarged, and FIG. 7 is a cross-sectional view showing the guide bearing structure.

  First, the vibration isolation unit 300 of the present embodiment is a final moving object that moves the holder 38 on which the CCD 31 is mounted in the X axis direction and the Y axis direction together with the optical LPF 32, the dust filter 33, and the like. An X frame (first moving body portion) 301 having a frame shape having a frame portion 301b surrounding an opening 301a around the photographing optical axis and formed in a desired size so that the holder 38 can be moved in the Y-axis direction; A frame having a frame shape having a frame portion 302b surrounding the opening 302a around the photographing optical axis and having a desired size so that the X frame 301 is movably mounted in the X axis direction and fixed to a camera body (not shown) Fixing member) 302.

  An X-axis drive mechanism 310x that moves the X frame 301 in the X-axis direction relative to the frame 302 and a Y-axis drive mechanism 310y that moves the holder 38 in the Y-axis direction relative to the X frame 301 are provided. By moving the holder 38 together with the X frame 301 in the X-axis direction relative to the frame 302 and moving the holder 38 in the Y-axis direction relative to the X frame 301, the CCD 31 mounted on the holder 38 can be moved in the XY plane. It is displaced so as to compensate for blurring in the axial direction and the Y-axis direction.

  Here, the configuration of the X-axis drive mechanism 310x will be described. The X-axis drive mechanism unit 310x includes an X-axis vibrator (first vibrator) 320x and a moving body (first moving body) 311x that is fixed to the X frame 301 and is driven together with the X frame 301. A sliding body (second moving body portion) 330x to be configured, and a pressing mechanism (biasing means) 340x for biasing the X-axis vibrator 320x toward the sliding body 330x are provided.

  The X-axis vibrator 320x is a rectangular piezoelectric body having drivers (drive units) 321x and 322x that generate elliptical vibration when a predetermined frequency voltage is applied in accordance with the operating principle of the vibrator 200 described in FIG. Provided on one side of 323x. The X-axis vibrator 320x has a vibrator holder 324x at a central position on the side opposite to the driver elements 321x and 322x of the piezoelectric body 323x, and the protrusion 325x formed on the vibrator holder 324x is a groove 342x (holding). The X-axis vibrator 320x is positioned and held so that movement in the X-axis direction is restricted. With such a configuration, the driving force due to elliptical vibration generated in the driver elements 321x and 322x acts 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 so as to be integrated with, for example, a screw 333x with respect to a part of the X frame 301 at a position where the driving elements 321x and 322x of the X-axis vibrator 320x are pressed to contact the sliding plate 332x. . 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. Here, as is apparent from FIG. 4, the sliding body 330x is formed with a size smaller than the X frame 301 formed in a desired size (a size corresponding to the X-axis vibrator 320x). Is. In addition, the X frame 301 is formed using a resin material, an aluminum alloy, a magnesium alloy having high vibration absorption, or the like, whereas the sliding plate 332x is formed using a wear-resistant ceramic or the like. The bearing 331x is formed by quenching a quenchable material such as ferritic stainless steel to increase the rigidity.

  In addition, the frame 302 includes a bearing (guide portion) 304x that is disposed at an opening-shaped attachment portion formed in the frame 302 and is fixed with a screw 303x so as to face the bearing 331x of the sliding body 330x. As shown in FIG. 7, a V-groove 305x along the X-axis direction is formed on the bearing 304x by adhering a V-groove plate 306x for preventing wear. As shown in FIG. 7, the bearing 331x has a V-groove 334x facing the V-groove 305x (V-groove plate 306x) of the bearing 304x. Here, the two balls 336x (rolling elements) positioned by the retainer 335x are sandwiched between the V grooves 305x and 334x, whereby the bearings 304x and 331x are arranged in one row along the X-axis direction. The structure has a single ball 336x. As shown in FIG. 6 and the like, the two balls 336x are positioned in the vicinity of the positions immediately below the driver elements 321x and 322x, and the movement in the X-axis direction is restricted by the retainer 335x. The rolling elements are not limited to balls, and may be rollers.

  The pressing mechanism 340x has one end fixed to the frame 302 by a screw 344x through a spacer 343x and holding the X-axis vibrator 320x, and a screw 345x that fixes the other end of the pressing plate 341x to the frame 302. A pressing spring 347x is provided around the spacer 346x and biases the pressing plate 341x so that the driver elements 321x and 322x of the X-axis vibrator 320x are pressed against the sliding plate 332x. The pressing force by the pressing mechanism 340x is set to a very large force of about 15N (Newton).

  The bearing 331x passes through the center of the ball 336x and can rotate around an axis parallel to the V-groove 334x. However, the bearing 331x is integrated with the X frame 301 and is separated from the bearing 331x in a direction different from the X-axis direction. One ball 307x (rolling element) is disposed between the frame 302 and the X frame 301 at the same position (most diagonal position farthest on the frame portion 302b). The ball 307x is maintained in a sandwiched state by a biasing force by a spring 308x locked between the frame 302 and the X frame 301 in the vicinity of the ball 307x, and is in the direction of the photographing optical axis (Z axis) of the X frame 301 with respect to the frame 302. Position to maintain spacing. Here, the urging force of the spring 308x only needs to maintain the clamping state of the ball 307x, and is set to be several steps weaker than the urging force of the pressing spring 347x. Accordingly, the moving body 311x including the X frame 301 and the sliding body 330x can move with respect to the frame 302 by three-point support with the two balls 336x and the one ball 307x. Further, since the ball 307x is disposed on the opposite side of the ball 336x with the photographing optical axis and the opening 301a interposed therebetween, the distance between the ball 307x and the ball 336x can be separated, so that a stable three-point support structure is provided. It can be. As described above, according to the present embodiment, the three balls (rolling bodies) can guide the moving direction of the moving body 311x and can also regulate the inclination, thereby enabling stable driving.

  On the other hand, the basic structure of the Y-axis drive mechanism unit 310y is the same as that of the X-axis drive mechanism unit 310x, and the same or corresponding parts are denoted by the same reference numerals with the suffix y, and description thereof is omitted. The Y-axis drive mechanism 310y uses the X frame 301 as a fixed member instead of the frame 302, and the holder 38 instead of the X frame 301 as the first moving body (or the third moving body). ) And a sliding body (second moving body portion or fourth movement) that is fixed integrally with the holder 38 and constitutes a moving body (second moving body) 311y to be driven together with the holder 38. Body part) 330y is provided.

  In addition, the image stabilization unit 300 according to the present embodiment includes an X-axis gyro 350x that detects a blur around the X-axis (pitch in the pitch direction) of the body unit 100 and a blur around the Y-axis (a blur in the yaw direction) of the body unit 100. The Y axis gyro 350y that detects the) is disposed on the frame 302. In addition, a position detection sensor 353 including a Hall element 351 disposed on the frame 302 and a magnet 352 disposed on a part of the holder 38 so as to face the Hall element 351 is provided. Then, an anti-vibration control circuit 355 that controls the vibrator drive circuit 354 for the X-axis vibrator 320x and the Y-axis vibrator 320y based on signals from the X-axis gyro 350x, the Y-axis gyro 350y, and the position detection sensor 353 is provided. The image stabilization control circuit 355 executes a control operation in accordance with an instruction from the Bucom 50.

  Next, the operation of the X-axis drive mechanism 310x will be described. When a predetermined frequency voltage is applied to the X-axis vibrator 320x to generate elliptical vibrations in the driver elements 321x and 322x, the driver elements 321x and 322x of the X-axis vibrator 320x are slid by the strong biasing force of the pressing mechanism 340. Since it is in pressure contact with 332x, the sliding body 330x is driven in the rotational direction of the elliptical vibration of the driver elements 321x and 322x.

  At this time, since the pressing force applied to the X-axis vibrator 320x is strong, if the rigidity of the sliding plate 332x and the bearing 331x constituting the sliding body 330x is weak, as shown by the phantom line in FIG. The sliding plate 332x and the bearing 331x are bent by the pressing force, and the driving elements 321x, 322x and the sliding plate 332x come into contact with each other, and the operation becomes unstable or stops operating.

  In this respect, in the present embodiment, since the sliding plate 332x and the bearing 331x constituting the sliding body 330x have high rigidity, the pressing contact state between the driver 321x, 322x and the sliding plate 332x is stabilized, and elliptical vibration is caused. The accompanying driving force is reliably transmitted to the sliding plate 332x, and can be driven in the rotational direction of elliptical vibration with high efficiency. At this time, the sliding body 330x side having the sliding plate 332x is not in surface contact with the frame 302 but is in contact with the rolling method by the balls 336x at the bearings 331x and 304x portions, so even if the pressing force is strong. The sliding body 330x moves reliably with little friction with respect to the frame 302. Since the bearings 331x and 304x have a single-row ball bearing structure along the X-axis direction, the sliding body 330x moves only in the X-axis direction when driven by the X-axis vibrator 320x. When the sliding body 330x moves in this way, the X frame 301 to which the sliding body 330x is fixed also moves in the X-axis direction integrally with the sliding body 330x. In other words, the moving direction of the X frame 330x is also guided by the engagement between the bearings 331x and 304x having a ball bearing structure of one row along the X axis direction.

  In such an operation, the bearing 331x passes through the center of the ball 336x and can rotate around an axis parallel to the V-groove 334x. However, the bearing 331x is integrated with the X frame 301, and the X-axis direction from the bearing 331x is One ball 307x is disposed between the frame 302 and the X frame 301 at different positions in different directions, and the moving body 311x composed of the X frame 301 and the sliding body 330x has two balls with respect to the frame 302. 336x and one ball 307x are supported at three points at a distance from each other, so that the frame 302 can be stably moved in the X-axis direction without causing a rotation due to rotation around an axis parallel to the V-groove 334x. Moving. Therefore, the guide support mechanism for the strong pressing portion with respect to the X-axis vibrator 320x may be a single-row ball bearing bearing structure along the X-axis direction by the bearings 331x and 304x, and the size and structure can be simplified.

  The Y-axis drive mechanism 310y operates in the same manner as the X-axis drive mechanism 310x.

  Next, the camera shake correction operation will be described. When a camera shake correction SW (not shown) in the camera operation SW 52 is turned on and a main SW (not shown) is turned on, a signal that causes the vibrator drive circuit 354 to execute an initial operation from the Bucom 50 to the image stabilization control circuit 355. Is transmitted from the vibrator driving circuit 354 to the X-axis vibrator 320x and the Y-axis vibrator 320y, and the X frame 301 and the holder 38 are placed on the X-axis so that the center of the CCD 31 is on the photographing optical axis. Driven in the axial direction and the Y-axis direction.

  The shake signal of the body unit 100 detected by the X-axis gyro 350x and the Y-axis gyro 350y is taken into the image stabilization control circuit 355. Here, in the X-axis gyro 350x and the Y-axis gyro 350y, a signal output from an angular velocity sensor that detects blur around one of the axes is amplified by a processing circuit and A / D converted to be subjected to an image stabilization control circuit. 355.

  The image stabilization control circuit 355 calculates a shake correction amount based on the output signals of the X-axis gyro 350x and the Y-axis gyro 350y, and outputs a signal corresponding to the calculated shake correction amount to the vibrator drive circuit 354. The holder 38 and the X frame 301 on which the CCD 31 is mounted are driven by a Y-axis vibrator 320y and an X-axis vibrator 320x that are operated by an electric signal generated by the vibrator drive circuit 354. The drive position of the CCD 31 (holder 38) is detected by a position detection sensor 353 and sent to an image stabilization control circuit 355 for feedback control.

  That is, the image stabilization control circuit 355 calculates the reference value based on the input signals from the X-axis gyro 350x and the Y-axis gyro 350y (hereinafter also referred to as “blur signal” or “blur angular velocity signal”). The calculation of the reference value is performed from when the main power of the camera is turned on until exposure for still image shooting is performed. As this calculation, there are a method of calculating a moving average value of a blur signal for a relatively long time, a method of obtaining a DC component by a low-pass filter having a relatively low cut-off frequency, and any method may be used. By subtracting the reference value obtained by this calculation from the blur signal, a signal from which the low frequency component of the blur signal is removed is obtained. Based on this signal and the output signal of the position detection sensor 353, the vibrator drive circuit 354 is controlled to move the position of the CCD 31 (holder 38) so as to compensate for the blur.

  Here, the correction operation during still image shooting will be described with reference to FIG. FIG. 9 is a schematic flowchart showing a correction operation during still image shooting. Note that this operation is not performed before the start of shooting preparation is instructed by the release SW (before IR ON), and starts when the start of shooting preparation is instructed by the release SW (when 1R is turned ON).

  When this operation is started, a correction amount is calculated using the above-described reference value, and shake correction driving is started according to the calculated correction amount (step S11). Subsequently, it is determined whether or not the shooting preparation start instruction by the release SW has been canceled (1R has been turned OFF) (step S12). If the instruction has been canceled (step S12; Yes), the process is started in step S11. The blur correction drive is stopped and the CCD 31 is centered (step S17), and the camera waits for an instruction to start photographing preparation (1R wait state).

  On the other hand, when the shooting preparation start instruction by the release SW is not canceled (step S12; No), it is subsequently determined whether or not the shooting start is instructed by the release SW (2R ON) (step S13). If not instructed (step S13; No), the process returns to step S12 and waits in an instruction waiting state. When the start of shooting is instructed by the release SW (step S13; Yes), the blur correction driving started in step S11 is stopped and the CCD 31 is centered (step S14). Subsequently, a correction amount is calculated using the held reference value, and blur correction driving is started according to the correction amount (step S15). Then, exposure is performed (step S16), and when the exposure is completed, the blur correction driving is stopped and the CCD 31 is centered (step S17), and the camera waits for an instruction to start photographing preparation (1R waiting state).

  According to the present embodiment, vibrators 320x and 320y that generate elliptical vibrations that are highly efficient and easily obtain a large driving force are used as driving sources, while moving bodies 311x and 311y have a desired size as an original moving object. The first moving body portion such as the X frame 301 and the holder 38 formed in this way and the second moving body portion such as the sliding body 330x and the sliding body 330y smaller than the first moving body portion are divided. Both are fixed and integrated by the structure, and the driving force transmission function and the moving direction from the vibrators 320x and 320y are provided by providing the sliding plates 332x and 332y and the bearings 331x and 331y in the smaller second moving body portion. The guide function is integrated, and the larger first moving body is integrated with the second moving body so as to simply follow and move, and only the smaller second moving body is rigid. To be higher While it is possible to increase the efficiency of driving force transmission, the first moving body part side does not require as high rigidity as the second moving body part side and is made to a desired size by a lightweight material. What is necessary is just to form and the exclusive guide mechanism which regulates the moving direction of a 1st moving body part is not required, and a driving force is large as a whole, and it can achieve high efficiency, small size, and weight reduction.

1 is a block diagram schematically showing mainly an electrical system configuration of a camera according to an embodiment of the present invention. FIG. It is a vertical side view which shows the structural example of an imaging unit. It is a schematic diagram which shows the operation principle of a vibrator. It is a disassembled perspective view which shows the structural example of an anti-vibration unit. It is a schematic side view of the vibration isolator which shows the shape of each part shown in FIG. 4 in a simplified manner. It is a schematic side view which extracts and expands and shows the X-axis drive mechanism part in FIG. It is sectional drawing which shows a guide bearing structure. It is explanatory drawing which shows a mode that bending arises with the pressing force with respect to a vibrator | oscillator. It is a schematic flowchart which shows the correction | amendment operation | movement at the time of still image photography.

Explanation of symbols

31 CCD
38 Holder 50 Bucom
301 X frame 302 Frame 304x, 304y Bearing 307x, 307y Ball 320x X-axis vibrator 320y Y-axis vibrator 321x, 322x Driver 321y, 322y Driver 330x, 330y Slider 331x, 331y Bearing 332x, 332y Slide plate 336x 336y Ball 340x, 340y Pressing mechanism 342x, 342y Holding part

Claims (8)

A vibrator that generates elliptical vibration in the drive unit when a predetermined frequency voltage is applied;
A fixing member having a holding portion for holding the vibrator;
A moving body that is driven by the elliptical vibration of the vibrator and moves relative to the fixed member;
With
The moving body is
A first moving body portion formed in a desired size;
A sliding portion that is in contact with the driving portion when pressed, and a guided portion that is provided on a side opposite to the sliding portion and engages with a guide portion included in the fixing member to guide a moving direction. And a second moving body portion that is higher in rigidity than the first moving body portion and is smaller than the first moving body portion and is fixed to the first moving body portion. The drive device characterized.   The moving direction of the first moving body portion that moves integrally with the second moving body portion is guided by the engagement between the guide portion of the fixed member and the guided portion of the second moving body portion. The drive device according to claim 1, wherein:   3. The driving apparatus according to claim 1, wherein the first moving body portion is formed of a resin material, aluminum, or magnesium.   An urging means for urging the vibrator so as to press the driving portion against the sliding portion from a side opposite to the guide portion across the second moving body portion and the vibrator is provided. The drive device according to any one of claims 1 to 3. The guide part and the guided part have rolling elements arranged in a line along the movement direction,
A single rolling element for positioning disposed in a clamped state by a biasing force between the first moving body portion and the fixed member at a position away from the guide portion in a direction different from the moving direction; The drive device according to claim 1, wherein A first vibrator that generates elliptical vibration in the drive unit when a predetermined frequency voltage is applied;
A fixing member having a first holding portion for holding the first vibrator;
The driving portion of the first vibrator is pressed, the moving direction is regulated in a first direction by a guide portion included in the fixing member, and the fixing is driven by elliptic vibration of the first vibrator. A first moving body that moves in a first direction relative to the member;
A second vibrator that is held by the first moving body having a second holding unit and generates elliptical vibration in the driving unit when a predetermined frequency voltage is applied;
The driving portion of the second vibrator is pressed, and the moving direction is regulated in a second direction different from the first direction by the guide portion of the first moving body, and the second vibrator A second moving body that is driven by the elliptical vibration of the first moving body and moves in a second direction with respect to the first moving body;
With
Of the first and second moving bodies, at least one moving body is:
A first moving body portion formed in a desired size;
A sliding portion that is in contact with the driving portion; and a guided portion that is provided on a side opposite to the sliding portion and that engages with the guide portion to guide a movement direction. A drive device comprising: a second moving body portion having a rigidity higher than that of the body portion and being smaller than the first moving body portion and fixed to the first moving body portion. In an imaging apparatus including a microcomputer that controls the operation of the entire imaging apparatus and moving the imaging element in a first direction and a second direction orthogonal to each other in a plane orthogonal to the imaging optical axis so as to compensate for blurring ,
A first vibrator that generates elliptical vibration in the drive unit when a predetermined frequency voltage is applied based on an instruction from the microcomputer;
A fixing member having a first holding part for holding the first vibrator and fixed to the imaging apparatus main body;
The driving portion of the first vibrator is pressed, the moving direction is regulated in a first direction by a guide portion included in the fixing member, and the fixing is driven by elliptic vibration of the first vibrator. A first moving body that moves in a first direction relative to the member;
A second vibrator that is held by the first moving body having a second holding unit and generates elliptical vibration in the driving unit when a predetermined frequency voltage is applied based on an instruction of the microcomputer;
The driving portion of the second vibrator is pressed, the moving direction is regulated in the second direction by the guide portion of the first moving body, and the second vibrator is driven by the elliptical vibration of the second vibrator. A second moving body that moves in the second direction with respect to the first moving body and that holds the image sensor on the photographing optical axis;
With
Of the first and second moving bodies, at least one moving body is:
A first moving body portion formed in a desired size;
A sliding portion that is in contact with the driving portion; and a guided portion that is provided on a side opposite to the sliding portion and that engages with the guide portion to guide a movement direction. An imaging apparatus comprising: a second moving body portion having a rigidity higher than that of the body portion and being smaller than the first moving body portion and fixed to the first moving body portion. In an imaging apparatus including a microcomputer that controls the operation of the entire imaging apparatus and moving the imaging element in a first direction and a second direction orthogonal to each other in a plane orthogonal to the imaging optical axis so as to compensate for blurring ,
A first vibrator that generates elliptical vibration in the drive unit when a predetermined frequency voltage is applied based on an instruction from the microcomputer;
A fixing member that is formed in a frame shape surrounding an opening around the photographing optical axis and has a first holding part that holds the first vibrator, and is fixed to the imaging apparatus body;
A first moving body portion having a frame shape surrounding an opening around the photographing optical axis and having a desired size;
The sliding portion of the first vibrator that is pressed and brought into contact with the sliding portion and the guide portion provided on the side opposite to the sliding portion and engaged with the fixing member in the first direction A guided portion whose movement direction is guided, which is higher in rigidity than the first moving body portion and smaller than the first moving body portion, and is fixed to the first moving body portion. A second moving body that is driven by elliptical vibration of the first vibrator and moves in a first direction with respect to the fixed member;
A second vibrator that is held by the first moving body portion having a second holding portion and generates elliptical vibration in the driving portion when a predetermined frequency voltage is applied based on an instruction of the microcomputer;
A third moving body portion that is formed in a desired size and that is disposed in the opening of the first moving body portion while holding the imaging element on a photographing optical axis;
The sliding portion of the second vibrator that is pressed and brought into contact with the sliding portion is engaged with a guide portion that is provided on the side opposite to the sliding portion and that the first moving body portion has. And a guided portion whose movement direction is guided in the direction of 2, the third moving body portion being higher in rigidity than the third moving body portion and smaller than the third moving body portion. A fourth moving body portion fixed to the portion and driven by the elliptical vibration of the second vibrator to move in the second direction with respect to the first moving body portion;
An imaging apparatus comprising:

Images