JP2012150234A - Driving device, and intermediate lens unit and lens unit using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To precisely hold a movable member at an arbitrary position in a driving device used in an imaging apparatus or the like.SOLUTION: The driving device includes: fixed frames 314a, 314b having a guiding shaft 318; a movable frame 313 which is guided by the guiding shaft 318 and movable with respect to the fixed frames 314a, 314b; a driving part having VCMs 350a, 350b for moving the movable frame 313 along the guiding shaft 318; an oscillator 324 which is fixed to the movable frame 313 and capable of oscillating in a direction in which the oscillator 324 comes into contact with the guiding shaft 318; and a biasing mechanism having a biasing spring 320 for biasing the oscillator 324 in a direction in which the oscillator 324 comes into contact with the guiding shaft 318.

Description

  The present invention relates to a driving device, an intermediate lens unit using the same, and a lens unit.

  In recent years, digital cameras that can shoot not only still images but also moving images have been commercialized, but the photographic lenses used for such cameras are optical lenses such as lenses that are electrically driven when performing focusing, zooming, etc. It has a movable frame that holds the element. The electric drive of the movable frame is required to be performed at high speed and precisely in order to accurately capture the photographing opportunity. On the other hand, when it is not necessary to electrically drive the movable frame, it is required that the battery is not consumed and the movable frame is precisely stopped and held at a predetermined position.

  As a driving mechanism for a photographic lens having an electric movable frame, for example, as disclosed in Japanese Patent Laid-Open No. 4-324408, a moving lens as a movable frame is connected to a voice coil linear actuator (hereinafter referred to as VCM). Some of them are directly driven. In the drive mechanism of this document, when the electric drive is not performed, the moving lens is held in a neutral position by a gimbal spring having one end fixed to a fixed frame.

JP-A-4-324408

  If focusing and zooming are not performed at high speed and precision in a photographic lens, the shooting opportunity will be missed or the image quality will be deteriorated. Therefore, it is necessary to drive the movable frame at high speed and with precision. On the other hand, there is a case where the movable frame is stopped at a predetermined position by focusing or zooming, and still image shooting or moving image shooting is continued for a long time in this state. Even if a disturbance (vibration shock from the outside) is applied, it is required to stop at a predetermined position accurately.

  For example, in the photographing lens disclosed in Japanese Patent Laid-Open No. 4-324408, a moving lens that is a movable frame is electrically driven by a VCM. The moving lens sleeve is precisely guided in the optical axis direction by fitting into a guide bar installed on an outer cylinder as a fixed frame. Since the VCM directly drives the moving lens, there is little mechanical backlash and more precise control is possible. Further, since the loss of energy is small because of direct driving, the moving lens can be driven at high speed. Further, one end of the gimbal spring, one end of which is fixed to the outer cylinder, is fixed to the moving lens, and the moving lens is held at the neutral position of the gimbal spring even when there is no electrical input to the VCM.

  However, when the moving lens tries to move from the neutral position due to the gimbal spring, the moving lens receives the spring force from the gimbal spring. As a result of the reaction force of the gimbal spring, the energy efficiency of driving the moving lens is deteriorated, or a response delay occurs, so that high speed driving cannot be performed. Further, when the displacement of the gimbal spring increases, the reaction force also increases in proportion to the displacement, and the control of the VCM becomes complicated. On the other hand, in order to reduce the reaction force described above, it is necessary to reduce the rigidity of the gimbal spring. Then, since the moving lens is positioned by the gimbal spring when it is not electrically driven, the position of the moving lens changes due to a small disturbance (vibration or impact), and the precise position cannot be maintained.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a driving device that can accurately hold a movable portion at an arbitrary position in a driving device used in an imaging device or the like. To do.

The invention of the drive device according to claim 1 that achieves the above object is as follows:
A first member having a guide portion;
A second member guided by the guide portion and provided to be movable relative to the first member;
A drive unit that relatively moves the second member along the guide unit;
A vibrator fixed to the second member and capable of vibrating in a direction contacting the guide portion;
And an urging mechanism for urging the vibrator in the abutting direction with respect to the guide portion.

The invention according to claim 2 is the drive device according to claim 1,
One of the first member and the second member is a fixed frame of the imaging apparatus, and the other is a movable frame that holds at least one lens of the imaging optical system of the imaging apparatus. Is.

The invention according to claim 3 is the drive device according to claim 2,
The guide portion is a guide shaft that guides the movable frame in the optical axis direction of the imaging optical system.

The invention of the intermediate lens unit according to claim 4 that achieves the above object,
An intermediate lens unit that can be mounted between a lens unit having a focus lens group and a camera body having an image sensor,
A fixed frame having a guide shaft along the optical axis and fixed to the camera body;
A movable frame guided by the guide shaft and provided to be movable with respect to the fixed frame;
A drive unit that moves the movable frame along the guide shaft;
A vibrator fixed to the movable frame and capable of vibrating in a direction contacting the guide shaft;
An urging mechanism for urging the vibrator in the abutting direction with respect to the guide shaft;
A movable lens fixed to the movable frame;
A sensor for detecting a position of the movable frame with respect to the fixed frame;
A communication unit capable of communicating with the camera body;
With
An instruction for wobbling the movable lens is received from the camera body via the communication unit, the movable unit is reciprocated in the optical axis direction by the drive unit, and the position of the movable frame with respect to the fixed frame is The communication unit is configured to transmit to the camera body.

The invention according to claim 5 is the intermediate lens unit according to claim 4,
A fixed lens having negative refractive power is provided on each of the object side and the image side of the movable lens, and the movable lens has positive refractive power.

The invention of the lens unit according to claim 6 that achieves the above object is as follows.
A lens unit having a focus lens group that can be attached to a camera body,
A fixed frame having a guide shaft along the optical axis and fixed to the camera body;
A movable frame guided by the guide shaft and provided to be movable with respect to the fixed frame;
A drive unit that moves the movable frame along the guide shaft;
A vibrator fixed to the movable frame and capable of vibrating in a direction contacting the guide shaft;
An urging mechanism for urging the vibrator in the abutting direction with respect to the guide shaft;
A movable lens fixed to the movable frame;
A sensor for detecting a position of the movable frame with respect to the fixed frame;
A communication unit capable of communicating with the camera body;
With
The camera body receives an instruction to perform a wobbling operation of the movable lens via the communication unit, and the drive unit reciprocates the movable frame in the optical axis direction, and the position of the movable frame with respect to the fixed frame is The communication unit is configured to transmit to the camera body and receive an instruction to drive the focus lens group from the camera body via the communication unit.

  According to the driving device of the present invention, the vibrator that is fixed to the second member and can vibrate in the direction of contact with the guide part, and the biasing mechanism that biases the vibrator in the direction of contact with the guide part, Therefore, the movable member can be accurately held at an arbitrary position.

It is a figure explaining the structure of the camera system containing the intermediate lens unit using the drive device which concerns on 1st Embodiment of this invention. It is a front view explaining the structure of the drive device which drives the movable lens of FIG. It is sectional drawing by the AA line shown in FIG. 2 of the intermediate lens unit of FIG. It is a figure explaining the structure of the voice coil motor (VCM) of FIG. It is a figure which expands and shows the part containing the vibrator | oscillator and guide shaft of FIG. It is a figure explaining the connection of the structure of the piezoelectric material of FIG. 5, and its control circuit. FIG. 3 is a conceptual diagram illustrating a configuration of a biasing mechanism that biases a vibrator with respect to a guide shaft in FIG. 2. It is a figure explaining the friction reduction by the vibrator | oscillator of FIG. It is a figure which shows the input signal to the piezoelectric material with respect to each time of FIG. It is a circuit diagram which shows roughly the control circuit of a piezoelectric material. It is a figure which shows the time chart of the signal of the control circuit of FIG. It is a flowchart explaining operation | movement of the camera system of FIG. 13 is a flowchart for explaining an autofocus (AF) operation in FIG. 12. It is sectional drawing containing the movable frame and guide shaft of the drive device which concern on the modification of this invention.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In each drawing used for the following description, the scale is different for each component in order to make each component large enough to be recognized on the drawing. It is not limited only to the quantity of the component described in the figure, the shape of the component, the ratio of the size of the component, and the relative positional relationship of each component.

(First embodiment)
FIG. 1 is a diagram illustrating a configuration of a camera system including an intermediate lens unit using the drive device according to the first embodiment of the present invention. As shown in FIG. 1, the camera system 10 is disposed between a body unit 100, a lens unit 200 that is a photographing lens for forming an optical image of a subject, and the body unit 100 and the lens unit 200. An intermediate lens unit 300 is included. The body unit 100 and the intermediate lens unit 300 and the intermediate lens unit and the lens unit 200 are configured to be detachable.

In the following description, the direction from the body unit 100 toward the subject is referred to as the front, and the opposite is referred to as the rear. Also, an axis that coincides with the optical axis O1 of the imaging optical system that the lens unit 200 and the intermediate lens unit 300 constitute is a Z axis, and two axes that are orthogonal to each other on a plane orthogonal to the Z axis are an X axis and a Y axis. To do.

  First, the detailed configuration of this camera system will be described. As shown in FIG. 1, in a state where the intermediate lens unit 300 is attached to the body unit 100 and the lens unit 200 is attached to the intermediate lens unit 300, the lens unit 200 is a photographing lens for forming an optical image of a subject. 202. Further, the intermediate lens unit includes an intermediate lens 302 on the rear side (imaging plane side) of the photographing lens 202. Furthermore, the body unit 100 is provided with an imaging device called a charge coupled device (CCD), a CMOS sensor, or the like, for example, at an imaging position of an imaging optical system composed of the photographing lens 202 and the intermediate lens 302. An imaging unit 117 is included. The intermediate lens unit 300 has, for example, the same magnification as the optical magnification, and when the movable lens 302a of the intermediate lens 302 is displaced in the optical axis direction, the image forming position is displaced with almost no change in the optical image magnification of the subject. It is configured.

  In the present embodiment, the operation of the lens unit 200 is controlled by a lens control microcomputer (hereinafter referred to as “Lucom”) 201 disposed in the lens unit 200. The operation of the body unit 100 is controlled by a body control microcomputer (hereinafter referred to as “Bucom”) 101 disposed in the body unit 100. Further, the operation of the intermediate lens unit 300 is controlled by an intermediate lens unit control microcomputer (hereinafter referred to as “Tucom”) 301 provided in the intermediate lens unit 300. However, the intermediate lens unit 300 may be controlled by the Bucom 101 or the Lucom 201 without providing the Tucom 301 in the intermediate lens unit 300.

  In a state where the intermediate lens unit 300 is attached to the body unit 100, the Tucom 301 and the Bucom 101 are electrically connected to each other via the communication connector 102a so as to communicate with each other.

  In the present embodiment, when the intermediate lens unit 300 is mounted on the body unit 100, the photographing is not possible, so that the movable lens 302a of the intermediate lens unit 300 is held in a predetermined position in an electrically non-movable state. It will remain (detailed later).

  Further, when the intermediate lens unit 300 is attached to the body unit 100 and the lens unit 200 is attached to the intermediate lens unit 300, the Lucom 201 and the Tucom 301 are electrically connected to each other via the communication connector 102b so as to communicate with each other. The The Tucom 301 and the Lucom 201 are configured to operate in cooperation with the Bucom 101 in a dependent manner. Further, power necessary for each unit is supplied from a power supply circuit 135 installed in the body unit 100 through the communication connectors 102a and 102b.

  The intermediate lens unit 300 may be configured integrally with the body unit 100, or the operation of the intermediate lens unit 300 may be controlled only by the Bucom 101. Further, the intermediate lens unit 300 may be configured integrally with the lens unit 200. In this case, the operation of the intermediate lens unit 300 may be controlled only by the Lucom 201.

  Further, the intermediate lens unit 300 and the lens unit 200 may be configured integrally with the body unit 100. In this case, the operations of the intermediate lens unit 300 and the lens unit 200 may be controlled only by the Bucom 101.

  The imaging lens 202 is held in the lens unit 200. The lens unit 200 is detachable through a body mount (not shown) provided on the front side (subject side) of the intermediate lens unit 300 and a lens mount (not shown) provided on the rear side (image sensor side) of the lens unit 200. It is. This attachment / detachment mechanism is of a so-called bayonet type, and with this configuration, the camera system 10 can exchange and install the lens unit 200 in various ways. For example, it is possible to attach a lens unit with or without a wobbling function, which will be described later, and using the wobbling function of the intermediate lens unit, high-speed contrast autofocus can be achieved with a lens unit without a wobbling function. It is possible. In the present embodiment, high-speed and high-precision contrast autofocus can be performed using any lens unit.

  In the present embodiment, the photographing lens 202 includes a focus lens 202a and a variable power lens 202b. The focus lens 202a is driven by an unillustrated stepping motor or an actuator such as a VCM provided in the lens driving mechanism 204. The zoom lens 202b is driven by an unillustrated stepping motor or an actuator such as a VCM provided in the zoom drive mechanism 206. Here, as a matter of course, the driving mechanism of the movable frame of this embodiment can be used as the driving mechanism for driving the focus lens 202a or the variable power lens 202b.

  A diaphragm 203 is disposed between the focus lens 202a and the variable power lens 202b of the lens unit 200. The diaphragm 203 is driven by an actuator such as a stepping motor (not shown) provided in the diaphragm drive mechanism 205. Information of the lens unit 200 such as a focusing distance, a focal length, and an aperture value of the photographing lens 202 is detected by a position encoder or the like (not shown), and is input to the intermediate lens unit 300 via the Lucom 201 and the communication connector 102b. It is input to Bucom 101 via 102a. On the other hand, information such as the position of the movable lens 302a of the intermediate lens unit 300 is detected by a position encoder (described later in detail) and input to the Bucom 101 via the communication connector 102a.

  The imaging unit 117 is held in the body unit 100 via an imaging unit moving mechanism unit 159 described later.

  In this embodiment, an optical filter 118 such as a low-pass filter and a dustproof filter 119 are disposed on the front side of the imaging unit 117. Piezoelectric bodies 120 a and 120 b are attached to the periphery of the dust filter 119. The piezoelectric bodies 120a and 120b are configured to vibrate the dust filter 119 at a predetermined frequency determined by dimensions and materials by the dust filter control circuit 121. Dust adhering to the dustproof filter 119 can be removed by the vibration of the piezoelectric bodies 120a and 120b.

  A shutter 108 having a form generally referred to as a focal plane shutter is disposed on the front side of the dust filter 119. The body unit 100 also includes a shutter charge mechanism 112 that charges a spring that drives the front curtain and rear curtain of the shutter 108, and a shutter control circuit 113 that controls the movement of the front curtain and rear curtain. . Note that the optical filter 118, the dustproof filter 119, and the shutter 108 are appropriately disposed as necessary, and the camera system 10 may be configured not to include them.

  The imaging unit 117 is electrically connected to the image processing unit 126 via an imaging unit interface circuit 122 that controls the operation of the imaging unit 117. The image processing unit 126 has a configuration for generating an image based on a signal output from the imaging unit 117.

  The image processing unit 126 has a configuration for performing predetermined image processing on an image using a storage area such as the SDRAM 124 or the Flash ROM 125. The image processing unit 126 calculates a contrast value in a predetermined region (focus area) for a plurality of images generated by displacing the focus lens 202a or the movable lens 302a in order to perform autofocus by a so-called contrast detection method. The image position with the best contrast is detected.

  The image processing unit 126 is electrically connected to an image display device 123 such as an LCD monitor disposed behind the body unit 100, and can display an image on the image display device 123. The image display device 123 also functions as a so-called electronic view finder that displays a shooting composition by the camera system 10 in real time. In this embodiment, the optical viewfinder is not provided. However, a so-called single-lens reflex optical viewfinder may be provided.

  The recording medium 127 is a recording medium such as a flash memory or an HDD, and is detachably provided in the body unit 100. The recording medium 127 records data such as an image captured by the camera system 10 (including sound in the case of a moving image).

  The nonvolatile memory 128 is a storage unit made of, for example, an EEPROM that stores predetermined control parameters necessary for controlling the camera system 10. The nonvolatile memory 128 is provided so as to be accessible from the Bucom 101.

  The Bucom 101 is connected with an operation display LED 130 for notifying the user of the operation state of the camera system 10 by display output, a camera operation SW 131, a built-in strobe 132 and a strobe control circuit 133 that drives an external strobe (not shown). Has been. The camera operation SW 131 is a switch group including operation buttons necessary for operating the camera system 10, such as a release SW, a mode change SW, and a power SW.

  Further, in the body unit 100, a battery 134 as a power source and a power supply circuit 135 that converts and supplies the voltage of the battery 134 to a voltage required by each circuit unit constituting the camera system 10 are provided. In addition, a voltage detection circuit (not shown) for detecting a change in voltage when current is supplied from an external power supply via a jack (not shown) is also provided.

  The camera system 10 of the present embodiment is configured to be able to move the imaging unit 117 in the X-axis direction and the Y-axis direction in order to correct camera shake, and includes an imaging unit moving mechanism unit 159. By holding the imaging unit 117 via the imaging unit moving mechanism unit 159, the camera system 10 of the present embodiment can mechanically move the imaging unit 117 in the X-axis direction and the Y-axis direction. .

  Specifically, the imaging unit moving mechanism unit 159 includes an X-axis gyro 160, a Y-axis gyro 161, an image stabilization control circuit 162, an X-axis actuator 163, a Y-axis actuator 164, an X frame 165, a Y frame 166, a frame 167, and position detection. A sensor 168 and an actuator drive circuit 169 are provided.

  The frame 167 is fixed to the body unit 100, and the X frame 165 is supported by the frame 167 so as to be movable in the X-axis direction. In addition, the Y frame 166 that holds the imaging unit 117 is supported by the X frame 165 so as to be movable in the Y axis direction. The X-axis actuator 163 and the Y-axis actuator 164 are configured to drive the X frame 165 and the Y frame 166 in the X axis direction and the Y axis direction, respectively. The position control of the X frame 165 and the Y frame 166 is performed by a position detection sensor 168 that detects the positions of the X frame 165 and the Y frame 166 and an actuator drive circuit 169 that controls the operations of the X axis actuator 163 and the Y axis actuator 164. Is called.

  Since the X-axis actuator 163 and the Y-axis actuator 164 drive the X frame 165 straight in the X-axis direction and the Y frame 166 in the Y-direction, respectively, the X-axis actuator 163 and the Y-axis actuator 164 also have It is possible to apply the drive mechanism of this embodiment.

  The X axis gyro 160 detects the angular velocity of rotation (blur) around the X axis of the camera system 10, and the Y axis gyro 161 detects the angular velocity of rotation around the Y axis of the camera system 10. The image stabilization control circuit 162 calculates a camera shake compensation amount from the detected angular velocity of the camera system 10, and displaces and moves the first imaging unit 117 so as to compensate for the shake. In the imaging unit moving mechanism unit 159, various actuators such as a rotary motor, a linear motor, and an ultrasonic motor can be used as the actuator that moves the imaging unit 117.

  With the configuration as described above, the imaging element moving mechanism unit 159 moves the imaging unit 117 according to the movement of the camera system 10, thereby blurring the subject image in the imaging unit 117 due to the movement of the camera system 10. It has a function to suppress, a so-called image pickup element shift type camera shake correction function.

  A coupling unit 180 is provided in the body unit 100 of the camera system 10. The coupling unit 180 has a shape generally called an accessory shoe or a hot shoe that can fix an external strobe device (not shown) or an electronic viewfinder (not shown).

  In the present embodiment, the coupling unit 180 is provided with a strobe contact 136 for electrically connecting an external strobe device and a strobe control circuit 133 disposed in the body unit 100.

  Next, details of the intermediate lens unit 300 will be described with reference to FIGS. FIG. 2 is a front view illustrating the configuration of a driving device that drives the movable lens 312a of the intermediate lens unit 300 of FIG. In the figure, the fixed frames 314a and 314b and the substrate 329 of the intermediate lens 300 are indicated by two-dot chain lines. FIG. 3 is a cross-sectional view of the intermediate lens unit of FIG. 1 taken along line AA shown in FIG. 4A and 4B are diagrams for explaining the configuration of the voice coil motors (VCM) 350a and 350b in FIG. 2. FIG. 4A is a front view thereof, and FIG. 4B is a cross-sectional view taken along line BB in FIG. It is sectional drawing. FIG. 5 is an enlarged view showing a portion including the vibrator 324 and the guide shaft 318 in FIG. 2, FIG. 5 (a) is a front view thereof, and FIG. 5 (b) is a C- It is C sectional drawing. The first member includes fixed frames 314a and 314b, the second member includes a movable frame 313, the guide portion includes a guide shaft 318, and the drive portion includes VCMs 314a and 314b.

  As shown in FIGS. 2 and 3, the fixed frames 314 a and 314 b are members constituting the outer cylinder of the intermediate lens unit 300. The movable frame 313 is a member that holds the lens 312a so as to be movable in the optical axis direction in the intermediate lens unit 300.

  A B mount 315 is fixed to the front end of the fixed frame 314a with a screw or the like (not shown). The B mount 315 and the L mount 216 of the lens unit 200 (not shown) are configured to be detachable by a so-called bayonet mechanism. The communication connector 102b in FIG. 1 includes a B contact 310 connected to the L contact 210 of the lens unit 200 in FIG. 3 and a contact spring 311 that presses the B contact toward the lens unit 200. Yes. The contact spring 311 is connected to a substrate 329 to which a Tucom 301 (not shown in FIG. 3) is connected. The outer peripheral portion of the lens 312b is fixed and held at the front center portion of the fixed frame 314a by adhesion or the like.

  On the other hand, a fixed frame 314b is fixed to the rear end of the fixed frame 314a with a screw or the like (not shown), and an L mount 316 is fixed to the rear end of the fixed frame 314b with a screw or the like (not shown). A B mount 115 of the body unit 100 is detachably attached to the L mount 316 by a bayonet mechanism. The communication connector 102a in FIG. 1 includes an L contact 317. Similarly to the lens 312b, the lens 312c is fixedly held at the center of the fixed frame 314b.

  The wobbling lens 312a of the intermediate lens unit 300 has a positive refractive power, and the object side lens 312b and the image side lens 312c have a negative refractive power. This is advantageous for reducing aberration fluctuations while ensuring the positive refractive power required for the wobbling lens. Furthermore, the optical magnification of the intermediate lens unit 300 can be made substantially equal, and even if the intermediate lens unit 300 is attached to the lens unit 200, the focal length of the lens unit 200 is not changed.

  Further, the guide shaft 318 and the rotation-preventing shaft 319 that are fitted to the recesses of the fixed frame 314a and the fixed frame 314b and are fixed to each other by the fixing means such as adhesion and the optical axis direction O1 are respectively connected to the movable frame. A hole 313a and a notch 313b provided in 313 are inserted.

  On the inner peripheral side of the hole 313a of the movable frame 313, a vibrator 324 configured by attaching the contact body 324b to the piezoelectric body 324a is fixed to the movable frame 313 by adhesion or the like so that the contact body 324b protrudes into the hole 313a. (See FIG. 5). Further, a biasing spring 320 as a tension coil spring is applied to the protrusion 313c provided on the outer peripheral end of the movable frame 313 and the protrusion 314c provided on the fixed frame 314a, and the cylindrical surface (concave surface) of the contact body 324b is guided to the guide shaft. It contacts so as to press against the cylindrical surface of 318. On the other hand, the biasing spring 320 is pulled in such a direction that the moment that the movable frame 313 rotates around the contact portion with the contact body 324b is slightly applied, and one wall of the notch 313b is pressed against the rotation shaft 319. Thus, the movable frame 313 is positioned with respect to the fixed frame 314a. The urging mechanism includes an urging spring 320.

  Two VCMs 350a and 350b are arranged symmetrically with respect to the optical axis O1, and the linear portions of the coils 321a and 321b wound with copper wires insulated in a track shape constituting the VCMs 350a and 350b are bonded to the movable frame 313 by bonding or the like. It is fixed. On the other hand, yokes 322a and 322b made of a magnetic material bent into a U-shape are fixed to the fixed frame 314a with screws, and rectangular plate-shaped magnets 323a and 323b are bonded and fixed inside the yokes 322a and 322b. ing. The straight portions of the coils 321a and 321b that are not fixed are arranged in a space between the yokes 322a and 322b facing the magnets 323a and 323b. Rectangular yokes 322a2 and 322b2 are attached to the U-shaped open ends of the yokes 322a and 322b so that the magnetic flux generated by the magnets 323a and 323b does not leak into spaces other than the space surrounded by the yoke. A so-called magnetic circuit is formed (see FIG. 4). Two coils are used here, but a copper wire may be wound around the lens 312a so as to surround the lens 312a so that the coil passes through the space surrounded by the yoke.

  The magnetic flux vector of the magnet 323a is directed to the opposing yoke 322a1 as shown in FIG. On the other hand, since a current flows through the coil 321a in a direction orthogonal to the magnetic flux, the coil 321a exerts a force Fc on the magnet 323a in a direction orthogonal to the magnetic flux vector direction and the current direction, that is, in the optical axis O1 direction. Receive. Although one VCM 350a has been described here, if the direction of the magnetic flux of the magnet 323b and the direction of the current flowing through the coil 323b are determined so that the force is also received in the same direction for the other VCM 350b, the coils 321a and 321b are forced in the same direction. The movable frame 313 to which they are fixed receives the force Fc × 2.

  At that time, the movable frame 313 is a cylindrical surface of the contact body 324b, and is in contact with the guide shaft 318 by the biasing force Fp of the biasing spring 320. If the friction coefficient between the contact body 324b and the contact surface of the guide shaft 320 is μ, a frictional force Ff = μ × Fp is generated between the contact body 324b and the guide shaft 320, and if Fc × 2> Ff. The movable frame 313 moves in the direction of the force received by the coils 321a and 321b (drive direction).

Further, it is conceivable that gravity is applied to the movable frame 313 in the driving direction. In this case, assuming that the weight Wk of the movable frame 313 and the gravitational acceleration g (= 9.8 m / s ² ), Fc × 2> Ff + Wk × g If so, the movable frame 313 can be moved. When actually controlling the position of the movable frame 313, it is preferable to configure the VCMs 350a and 350b so that a driving force more than twice the above driving force is generated.

  In the present embodiment, by causing the vibration direction 340 of the vibrator 324 to substantially coincide with the direction in which the biasing force Fp is applied by a method described later, the friction force Ff acting on the contact body 324b and the guide shaft 320 by vibrating the vibrator 324 is obtained. When the movable frame 313 can be controlled by the VCMs 350a and 350b and the movable frame is not moved, the vibrator 324 is not vibrated and the movable frame 313 is held at a predetermined position of the guide shaft 320 by the friction force Ff. It is configured as follows.

  The position of the movable frame 313 in the optical axis direction is determined by providing a plate-like sensor protrusion 313d on a part of the movable frame 313 and providing the absolute position sensor 325 for detecting a predetermined position of the sensor protrusion 313d on the fixed frame 314a. Is detected. The sensor protrusion 313d shown here is a light shielding plate, the absolute position sensor 325 is a photo interrupter, and detects the position where the light of the light emitting element of the photo interrupter is shielded by the light shielding plate or the position where the light shielding is released. . Although an optical sensor is used here, a magnetic sensor, a capacitance sensor, or the like may of course be used.

  On the other hand, the scale 327 attached to the movable frame 313 and the sensor 326 attached to the fixed frame 314a detect the relative position of the movable frame 313 in the optical axis direction with respect to the fixed frame 314a, and are positioned more than the absolute position sensor 325. High detection accuracy. Specifically, the scale 327 is a magnetic sheet in which the N pole and the S pole are magnetized at the same interval in the moving direction of the movable frame 313, and the sensor 326 is a GMR (giant magnetoresistive) element. A sine wave voltage is output at magnetic intervals. At this time, the magnetization interval is several μm to several hundred μm, and in the case where the position detection accuracy is increased from the magnetization interval, a sine wave signal multiplication circuit is incorporated into the control circuit of the sensor 326 to obtain one cycle of the sine wave. Position detection can be performed at smaller intervals so that an output signal can be output in multiple divisions.

  By detecting the reference position of the movable frame 313 with the absolute position sensor 325 and detecting the relative position from the reference position with the sensor 326, the position of the movable frame 313 can be detected with high accuracy. Further, even when the position of the movable frame 313 is changed by an external force such as vibration or shock when the circuit is not operating, the movable frame 313 performs an operation of passing the reference position through the absolute position sensor 325 to detect the reference position. As a result, the accurate position of the movable frame 313 can be detected.

  FIG. 6A is an exploded perspective view showing details of the piezoelectric body 324a. The piezoelectric body 324a is composed of a laminated piezoelectric body configured by stacking a large number of piezoelectric single plates made of piezoelectric ceramics such as lead zirconate titanate. The basic configuration 410 includes a rectangular plate-shaped piezoelectric plate A401 in which an electrode C401c as an internal electrode is formed on one surface and a rectangular plate-shaped piezoelectric plate B402 in which an electrode C402c as an internal electrode is formed on one surface. A pair is formed, and a plurality of pairs are laminated. The electrodes C401c and 402c are drawn to different side positions, and are formed on the side surfaces of the piezoelectric plate A401 and the piezoelectric plate B402 which are laminated and the piezoelectric plates C401c and 402c having no internal electrode are laminated and fired. The internal electrodes are connected to every other piezoelectric plate by the electrodes A401a and 402a and the electrodes B401b and 402b, and two electrodes, that is, the electrode A403a and the electrode B403b are formed on the surface of the outermost piezoelectric plate C403. ing. Although a plurality of piezoelectric single plates are stacked in FIG. 6A, a similar configuration is possible even if the piezoelectric single plates are manufactured in a folded form.

  In the laminated piezoelectric material formed in this manner, the piezoelectric plates A and B are polarized in the same direction in the plate thickness direction by applying a high voltage between the electrode A 403a and the electrode B 403b. Therefore, as shown in FIG. 6B, when one of the electrodes A and B of the polarized piezoelectric body 324a is connected to the ground and the other is connected to the signal output terminal of the control circuit 405, the frequency voltage is applied. The piezoelectric body 324a expands and contracts in the thickness direction.

  Next, the reduction of the frictional force between the contact body and the guide shaft in the mechanism of the present embodiment will be described with reference to FIG. 7, FIG. 8, and FIG. FIG. 7 is a conceptual diagram illustrating the configuration of an urging mechanism for urging the vibrator with respect to the guide shaft of FIG. 2. The movable frame 313, the fixed frames 314 a and 314 b and the vibrator 324 in FIGS. A mechanism for urging the guide shaft 318 to the guide shaft 318 is shown in a simplified manner. In FIG. 7, the piezoelectric body 324 a is in a non-vibrating state, and the contact body 324 b is in contact with the guide shaft 318. The piezoelectric body 324a vibrates in the direction in contact with the guide shaft 318, that is, in the normal direction of the contact surface between the piezoelectric body 324a and the guide shaft 318. Further, the biasing spring 320 biases the contact body 324b in a direction in which the contact body 324b comes into contact with the guide shaft 318. FIG. 8 is a diagram for explaining the friction reduction by the vibrator of FIG. 7. In FIG. 7, the state of the guide shaft 318 and the vibrator 324 when the piezoelectric body 324a is vibrated by applying a frequency voltage for a predetermined time T0. Displayed for each T6. FIG. 9 is a diagram showing an input voltage signal to the piezoelectric body 324a for each time T0 to T6 corresponding to (a) to (f) of FIG.

When a sine wave voltage of 20 kHz or more is applied to the piezoelectric body and ultrasonic vibration with an amplitude of about 1 μm is generated on the contact surface of the contact body 324b with the guide shaft 318, the contact body 324b is almost guided as shown in FIG. The shaft 318 is not in contact. More specifically, in FIG. 8A in the initial state in which no voltage is applied to the piezoelectric body 324a, the contact body 324b is urged and brought into contact with the guide shaft 318 by the urging force of the urging spring 320. When the piezoelectric body 324a is vibrated, acceleration of several tens of thousands m / s ² level due to ultrasonic vibration is applied to the contact body 324b. Accordingly, the contact body 324b is preferably a highly rigid metal or ceramic, and more preferably a material such as ceramic powder, glass fiber, or carbon fiber mixed with a highly rigid resin such as PPS in order to suppress audible sound. Further, the contact body 324b and the piezoelectric body 324a are preferably joined with a highly rigid epoxy adhesive or the like. On the other hand, the guide shaft 318 to be contacted is preferably made of a highly rigid metal, and in the case of this embodiment, the magnets of the VCMs 350a and 350b are disposed nearby, and nonmagnetic stainless steel or the like is more preferable.

  Next, when a voltage is applied to the piezoelectric body 324a so that the piezoelectric body 324a extends, the piezoelectric body 324a comes into contact with a force that is a product of the acceleration of displacement of the piezoelectric body 324a and the total mass of the movable frame 313 and the vibrator 324. The body 324b is urged by the guide shaft 318, the displacement acceleration gradually decreases to 0, and the maximum voltage is applied, and the piezoelectric body 324a is expanded to the maximum (FIG. 8B). If the initial generated acceleration is very large, the contact body 324b may not contact the guide shaft 318 in this state depending on conditions.

  After the maximum deformation, the piezoelectric body 324a starts to shrink and returns to the initial state. At this time, the biasing spring 320 cannot sufficiently pull back the displacement due to the acceleration generated by the piezoelectric body (the piezoelectric body has a small time constant, but the biasing spring has a relatively large time constant, so a response delay occurs. Therefore, the contact body 324b is not in contact with the guide shaft 318 (FIG. 8C).

  The state in which the contact body 324b does not contact the guide shaft 318 continues even when the maximum voltage is applied to the piezoelectric body 324a in the direction in which the piezoelectric body 324a is contracted (FIG. 8D).

  Next, the voltage applied to the piezoelectric body 324a is reduced to 0, and the piezoelectric body 324a returns to the initial displacement, but the contact body 324b does not contact the guide shaft 318 (FIG. 8E).

  Further, a voltage is applied to the piezoelectric body 324a in the extending direction, and when the piezoelectric body 324a extends, the contact body 324b comes into contact with the guide shaft 318 at a predetermined position, and acceleration is applied to the movable frame 313 in a direction in which the contact body 324b moves away from the guide shaft 318. It is added (FIG. 8 (f)).

  When a voltage is applied to the piezoelectric body 324a again in a contracting direction and the piezoelectric body 324a returns to the initial displacement, the contact body 324b and the guide shaft 318 are not brought into contact again (FIG. 8G). When the piezoelectric body vibrates, the expansion and contraction of the piezoelectric body 324a is repeated with (c) to (g) in FIG. 8 as one cycle. 8A to 8C are in a state of transient characteristics from the stationary state to the occurrence of steady vibration, and therefore, FIGS. 8C to 8G are repeated in the steady state.

  The contact body 324b contacts the guide shaft 318 in one cycle from (c) to (g) in FIG. 8 only for an instant in the vicinity of FIG. 8 (f), and most of the time in one cycle is in a non-contact state. In this period, the frictional force Ff is zero. Therefore, the average frictional force Ff in one cycle is very small. Actually, if the VCMs 350a and 350b operate in a non-contact state, the frictional force Ff operates at 0, and the frictional force is instantaneously generated in the state shown in FIG. Since the vibration period is very small, it operates smoothly as if the frictional force is constantly reduced. As can be seen from this operation, the contact time of the contact body 324b with the guide shaft 318 is changed by changing the vibration amplitude of the piezoelectric body. When the vibration amplitude is very small (the amplitude is set to a value close to 0), the contact body 324b and the guide shaft 318 are hardly changed from the constantly contacted state, and the frictional force Ff≈μFp. Here, μ is a coefficient of friction between the contact surfaces of the contact body 324b and the guide shaft 318, and Fp is an urging force of the urging spring 320.

  FIG. 10 is a circuit diagram schematically showing the configuration of the control circuit 405 of the piezoelectric body 324a in the intermediate lens unit 300 of the camera system 10. As shown in FIG. FIG. 11 is a time chart showing each signal output from each component in the control circuit 405 of FIG. Here, the control circuit 405 constitutes a part of the movable frame driving mechanism 303 of FIG.

  The control circuit 405 illustrated here has a circuit configuration as shown in FIG. 10, and in each part, signals having waveforms (Sig1 to Sig4) shown in the time chart of FIG. 11 are generated. It is controlled as follows.

  As illustrated in FIG. 10, the control circuit 405 includes an N-ary counter 182, a 1/2 frequency divider 183, an inverter 184, a plurality of MOS transistors Q00, Q01, Q02, a transformer 185, and a resistor R00.

  A ON / OFF switching operation of the MOS transistor Q01 and the MOS transistor Q02 connected to the primary side of the transformer 185 generates a signal (Sig4) having a predetermined period on the secondary side of the transformer 185. The piezoelectric body 324a is driven based on the signal of this predetermined period, and vibrations as shown in FIG. 8 are generated.

  The Tucom 301 controls the control circuit 405 through the two IO ports P_PwCont and IO port D_NCnt provided as control ports and the clock generator 186 present in the Tucom 301 as follows. The clock generator 186 outputs a pulse signal (basic clock signal) to the N-ary counter 182 at a frequency sufficiently faster than the signal frequency applied to the piezoelectric body 324a. This output signal is a signal Sig1 having a waveform represented by the time chart in FIG. The basic clock signal is input to the N-ary counter 182.

  The N-ary counter 182 counts the pulse signal and outputs a count end pulse signal every time it reaches a predetermined value “N”. That is, the basic clock signal is divided by 1 / N. This output signal is a signal Sig2 having a waveform represented by the time chart in FIG.

  In this divided pulse signal, the duty ratio between High and Low is not 1: 1. Therefore, the duty ratio is converted to 1: 1 through the 1/2 frequency dividing circuit 183. The converted pulse signal corresponds to the signal Sig3 having a waveform represented by the time chart in FIG.

  In the High state of the converted pulse signal, the MOS transistor Q01 to which this signal is input is turned on. On the other hand, this pulse signal is applied to MOS transistor Q02 via inverter 184. Therefore, in the low state of the pulse signal, the MOS transistor Q02 to which this signal is input is turned on. When the MOS transistor Q01 and the MOS transistor Q02 connected to the primary side of the transformer 185 are alternately turned on, a signal having a cycle such as the signal Sig4 in FIG. 11 is generated on the secondary side.

  The winding ratio of the transformer 185 is determined from the output voltage of the unit of the power supply circuit 135 and the voltage necessary for driving the piezoelectric body 324a. The resistor R00 is provided to limit the excessive current flowing through the transformer 185. The output voltage of the power supply circuit 135 is supplied from the body unit 100 to the intermediate lens unit 300 through the communication connector 102a.

  When driving the piezoelectric body 324a, the MOS transistor Q00 must be in an ON state, and a voltage must be applied from the power supply circuit 135 to the center tap of the transformer 185. In this case, ON / OFF control of the MOS transistor Q00 is performed via the IO port P_PwCont of the Tucom 301. The set value “N” of the N-ary counter 182 can be set from the IO port D_NCnt of the Tucom 301. Therefore, the Tucom 301 can arbitrarily change the drive frequency of the piezoelectric body 324a by appropriately controlling the set value “N”. It is. Alternatively, the vibration frequency of the vibrator 324 may be increased by using the drive frequency as the resonance frequency of the vibrator 324 so as to operate at a low voltage. When the resonance frequency is set, it is necessary to detect the vibration state of the piezoelectric body 324a and to control the resonance frequency. The vibration state can be detected by detecting a current input to the piezoelectric body 324a, for example.

At this time, the frequency can be calculated by the following equation (7). That is,
fdrv = fpls / 2N (7)
Here, N is a set value for the N-ary counter 182, fpls is a frequency of an output pulse of the clock generator 186, and fdrv is a frequency of a signal applied to the piezoelectric body 324 a. The calculation based on the equation (7) is performed by the CPU (control means) of the Tucom 301.

  Further, in this embodiment, fdrv is preferably set to a frequency of 20 kHz or more. The piezoelectric body 324a vibrates at a frequency of fdrv, but this frequency band is an ultrasonic region and cannot be heard by humans. The camera system 10 is also used for shooting moving images. At that time, there is a case where sound is recorded at the same time, and the drive sound is required to be small. Since the sound in the ultrasonic band exceeds the human audible range, a normal microphone does not detect it. Furthermore, in the present embodiment, the applied voltage input to the piezoelectric body 324 is a sine wave, but may be a rectangular wave or a triangular wave.

  The operation of the camera system 10 will be described below with reference to the flowcharts of FIGS. FIG. 12 is a flowchart for explaining the operation of the camera system of FIG. FIG. 13 is a flowchart for explaining the autofocus (AF) operation in FIG.

  The operation control of the imaging sequence of the camera system shown in FIG. 12 is mainly performed by the control of Bucom 101.

  First, when the power SW of the camera operation SW 131 of the camera system 10 is operated, the Bucom 101 executes a predetermined initial setting sequence at the time of starting the camera system (step S101). In this initial setting sequence, the Bucom 101 reads out necessary control parameters from the nonvolatile memory 128.

  Next, the Bucom 101 detects the presence or absence of a strobe or an electronic viewfinder connected to the combining unit 180 (step S102).

  Further, the Bucom 101 detects the state of each switch of the camera operation SW 131 (step S103). The switch for detecting the state includes a switch for switching a recording / playback mode, switching a moving image / still image, and the like. The camera operation SW is not limited to a switch realized by hardware, and includes a switch that can be switched by software.

  Thereafter, the Bucom 101 detects whether the camera system is in the playback mode or the recording mode (step S104). If the camera system is in the playback mode, a moving image or still image playback program is activated and the image display device 123 is activated. A reproducible image selection screen is displayed on the screen, and the image is reproduced according to the user's instruction (step S105). The details of the reproduction mode are not directly related to the present application, and thus the description thereof is omitted.

  Next, when the playback mode is not set, it is detected which mode is the still image shooting mode or the moving image shooting mode. Specifically, ON / OFF of a moving image button which is a switch for switching between moving images and still images in the camera operation SW 131 is detected (step S106). When the moving image button is turned on, the recording flag indicating whether the moving image is being recorded is reversed (step S107). That is, every time the moving image button is turned ON, the recording flag is switched ON / OFF. Next, a recording flag is detected (step S108), and if it is ON, automatic exposure (AE) processing is performed (step S109), and then AF operation using wobbling is performed (step S110).

  FIG. 13 is a flowchart for explaining the AF operation (steps S110 and S116) of FIG. In this AF operation, the minute movement of the movable lens 302a of the intermediate lens unit, which is a wobbling lens, in the optical axis O1 direction is optically equivalent to the minute movement of the focus lens 202a in the optical axis direction. The direction in which the focusing position of the focusing lens 202a exists is recognized by the AF evaluation value (contrast value) at the position where the imaging optical system is configured and the movable lens 302a is slightly moved in the optical axis direction. Move.

  First, the Bucom 101 detects whether the camera system is in the AF mode state (step S201). When not in the AF mode, the operation for the non-AF mode is performed. The non-AF mode processing is omitted because it is not directly related to the contents of the present invention.

  If the camera system is in the AF mode state, it is next detected whether it is in the AF start state (step S202). In this step, for example, in the case of still image shooting, it is determined whether or not the AF release state is detected by detecting whether or not the first release button is in an ON state. In the AF start state, in accordance with an instruction from Bucom 101, Tucom 301 vibrates and drives the piezoelectric body 324a of the vibrator 324 to reduce the frictional force Ff acting on the contact body 324b and the guide shaft 320.

  When the frictional force Ff is reduced by driving the piezoelectric body 324a, the Tucom 301 drives the VCMs 350a and 350b by the movable frame driving mechanism 303 to wobble the movable lens 302a (step S204). Since the frictional force Ff is reduced, the movement of the movable lens 302a can be easily controlled.

  The Bucom 101 moves the position of the lens 302a by wobbling, and the image capturing unit 117 captures an image a plurality of times (for example, three times) (step S205). From the captured image, the image processing unit 126 detects the contrast value of each image (step S206). The difference between the maximum value and the minimum value of the contrast value is compared with an allowable value (step S207). If the contrast value is larger than the allowable value, the direction in which the focusing lens 202a is in focus can be determined from the difference in contrast value. Then, the lens driving mechanism 204 drives the focusing lens 202a toward the in-focus position via the Lucom 201 (step S208). Thereby, the focusing lens 202a can be brought close to the in-focus position.

  The Bucom 101 repeats the processing from step S204 to step S208, and when the obtained contrast value difference is less than or equal to a predetermined allowable value (step S207), the contrast is in the best state, that is, the in-focus state. And the AF process is terminated. At this time, the Tucom 301 first stops wobbling (step S209), that is, the movable frame drive mechanism 303 is stopped, and the VCMs 350a and 350b are stopped. Further, the driving of the piezoelectric body 324a of the vibrator 324 is also stopped (step S210), and the movable lens 312a is brought into the in-focus position without any further electric input by the frictional force Ff generated between the contact body 324b and the guide shaft 320. Precisely held by.

  Next, as shown in FIG. 12, when the AF operation (step S110) is completed, moving image shooting (step S111) is performed. The captured moving image is processed by the image processing unit 126 (step S112) and recorded on the recording medium 127 (step S113).

  Thereafter, unless the power is turned off, it is determined that the power is on (step S121), and the processing of Bucom 101 returns to step S104. When no special operation is performed, the operations from the AE operation (step S109) to the image recording (step S113) are repeated through steps S104, S106, and S108, and moving image shooting is continued.

  Next, when the moving image button is operated from the moving image shooting mode described above, the Bucom 101 detects that the moving image button is turned on (step S106), and inverts the recording flag (step S107). As a result, it is determined that the moving image recording state is not set (step S108), the process proceeds to the still image shooting mode, and the moving image shooting / recording ends. However, the image display device continues the moving image display (live view display) until the power is turned off in step S121.

  In the still image shooting mode, the Bucom 101 detects whether the release SW has been pressed halfway by the photographer, that is, whether the first release button has been turned ON (step S114). When it is detected that the first release button is turned on, an automatic exposure (AE) process is performed (step S115), and then an AF operation using wobbling is performed (step S116). In step S116, the AF operation shown in FIG. 13 is performed. At that time, the image captured in step S205 is displayed on the image display device 123.

  Next, as shown in FIG. 12, when the AF operation (step S116) is completed, the Bucom 101 returns to step S104 via step S117 for detecting power OFF. Unless the user changes the mode, after step S104, step S106, and step S108, it is detected again in step S114 whether the first release button has been turned ON. Here, since the 1st release button is already ON, it branches to “NO”.

  Next, the Bucom 101 detects the operation of the second release button, which is a fully-pressing operation of the release SW (step S117), and when the second release button is turned on, it takes a still image (step S118). The image data captured in step S118 is processed by the image processing unit 126 via the imaging unit interface circuit 122 (step S119), displayed on the image display device 123, and recorded on the recording medium 127 (step S120).

  On the other hand, if the second release button is OFF in step S117, the process returns to step S104 via step S121, and the processes of steps S104, S106, S108, S114, S117, and S121 are repeated unless a special operation is performed. In the still image shooting mode, when the first release button is ON, the image captured by the AF operation (step S116) is displayed on the image display device 123, and each time the second release button is turned ON, the still image is displayed one frame at a time. Photographing and recording (steps S118 to S120) are executed.

  The camera system 10 performs image reproduction, still image shooting, and video shooting until power-off is detected (step S121) after image recording (step S113 and step S120) in moving image or still image shooting.

  As described above, according to the present embodiment, the vibrator fixed to the movable frame and the vibrator are biased in the vibration direction with respect to the guide shaft to the intermediate lens unit that performs AF by wobbling of the imaging apparatus. In the state where the vibrator is vibrated using the driving device having the urging mechanism, the frictional force of the contact surface between the guide shaft and the movable frame is smaller than the state where the vibrating portion is not vibrated. The movable frame of the lens can be driven at high speed and precisely, and the movable frame can be kept at an arbitrary position without electrical input. More specifically, focusing and zooming of the photographic lens can be realized at high speed and precision, and the focusing position and zooming position can be held precisely and at any position without electrical input, making it extremely easy to use. A good lens can be provided.

(Modification)
In FIG. 14, the vibrator A330 and the vibrator B331 are arranged along the guide shaft 318, and the two contact bodies 330b and 331b come into stable contact with the guide shaft. In addition, by using a plurality of piezoelectric bodies, larger vibrations can be generated at a low voltage. Furthermore, since the vibrator A330 and the vibrator B331 are arranged symmetrically with respect to the biasing spring 320, the operation is more stable.

  Note that the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the spirit or idea of the invention that can be read from the claims and the entire specification. For example, the drive device according to the present invention can be applied not only to a camera system but also to various electronic devices such as a printer and a scanner having a movable part.

  In the above-described embodiment, the driving mechanism according to the present invention is applied to the wobbling lens. However, the driving mechanism according to the present invention may be applied to other lenses, for example, a focusing lens or a zooming lens. Further, the moving direction of the lens is not limited to the optical axis direction, and it is also possible to provide a guide portion along the direction perpendicular to the optical axis and drive the lens along this guide portion.

  In the above-described embodiment, what is called a lens is not limited to a single lens, but includes a lens group constituted by a plurality of lenses and a lens constituted by joining a plurality of lenses.

  Furthermore, in the said embodiment, although the 1st member was used as the fixed frame and the 2nd member was the movable frame, the structure which uses the 1st member as a movable frame and the 2nd member as a fixed frame is also possible. In this case, for example, the movable frame has a guide shaft that is inserted into the hole of the fixed frame, and a vibrator that vibrates in a direction in contact with the guide shaft is fixed to the fixed frame. Further, the movable portion is moved relative to the fixed portion by the driving portion. That is, the fixed part is moved relative to the movable part.

  The intermediate lens unit may be integrated with the lens unit. In that case, the lens control microcomputer of the lens unit receives an instruction from the camera body to perform a wobbling operation of the movable lens via the communication unit, and is driven. The movable frame is reciprocated in the optical axis direction by the unit, and the position of the movable frame with respect to the fixed frame is transmitted from the communication unit to the control microcomputer of the camera body. The control microcomputer of the camera body causes the lens control microcomputer of the lens unit to drive the focus lens group via the communication unit, and the AF operation is executed.

  The present invention is not limited to the form of the lens of the digital camera described in the above embodiment, but a recording device having a photographing function, a mobile phone, a PDA, a personal computer, a game machine, a digital media player, a television, a GPS, a clock, etc. It can also be applied to other electronic devices.

10 camera system,
100 camera body,
101 microcomputer for body control (control unit, identification unit, calculation unit),
117 imaging unit,
126 image processing unit,
128 non-volatile memory (storage unit),
135 power supply circuit,
159 imaging unit moving mechanism unit,
180 joints,
200 lens unit,
201 a lens control microcomputer;
202 photographic lens,
300 Intermediate lens unit,
302 intermediate lens,
313 Movable frame 314a, 314b Fixed frame 318 Guide shaft 320 Biasing spring 324 Vibrator 324a Piezoelectric body 324b Contact body

Claims (6)

A first member having a guide portion;
A second member guided by the guide portion and provided to be movable relative to the first member;
A drive unit that relatively moves the second member along the guide unit;
A vibrator fixed to the second member and capable of vibrating in a direction contacting the guide portion;
A drive device comprising: an urging mechanism that urges the vibrator in the abutting direction with respect to the guide portion.   One of the first member and the second member is a fixed frame of the imaging apparatus, and the other is a movable frame that holds at least one lens of the imaging optical system of the imaging apparatus. The drive device according to claim 1.   The drive device according to claim 2, wherein the guide portion is a guide shaft that guides the movable frame in an optical axis direction of the imaging optical system. An intermediate lens unit that can be mounted between a lens unit having a focus lens group and a camera body having an image sensor,
A fixed frame having a guide shaft along the optical axis and fixed to the camera body;
A movable frame guided by the guide shaft and provided to be movable with respect to the fixed frame;
A drive unit that moves the movable frame along the guide shaft;
A vibrator fixed to the movable frame and capable of vibrating in a direction contacting the guide shaft;
An urging mechanism for urging the vibrator in the abutting direction with respect to the guide shaft;
A movable lens fixed to the movable frame;
A sensor for detecting a position of the movable frame with respect to the fixed frame;
A communication unit capable of communicating with the camera body;
With
An instruction for wobbling the movable lens is received from the camera body via the communication unit, the movable unit is reciprocated in the optical axis direction by the drive unit, and the position of the movable frame with respect to the fixed frame is An intermediate lens unit configured to transmit from the communication unit to the camera body.   The intermediate lens unit according to claim 4, further comprising a fixed lens having negative refractive power on each of the object side and the image side of the movable lens, wherein the movable lens has positive refractive power. A lens unit having a focus lens group that can be attached to a camera body,
A fixed frame having a guide shaft along the optical axis and fixed to the camera body;
A movable frame guided by the guide shaft and provided to be movable with respect to the fixed frame;
A drive unit that moves the movable frame along the guide shaft;
A vibrator fixed to the movable frame and capable of vibrating in a direction contacting the guide shaft;
An urging mechanism for urging the vibrator in the abutting direction with respect to the guide shaft;
A movable lens fixed to the movable frame;
A sensor for detecting a position of the movable frame with respect to the fixed frame;
A communication unit capable of communicating with the camera body;
With
The camera body receives an instruction to perform a wobbling operation of the movable lens via the communication unit, and the drive unit reciprocates the movable frame in the optical axis direction, and the position of the movable frame with respect to the fixed frame is A lens unit configured to transmit from the communication unit to the camera body and receive an instruction to drive the focus lens group from the camera body via the communication unit.

Images