JP2006003462A - Optical instrument and photographing system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical instrument capable of selecting a transmission means of the optimum transmission method responding to a photographing mode and the like. <P>SOLUTION: The optical instrument comprises a movable lens unit L3, an actuator which generates a driving force for driving a lens unit, a first transmission means 5 and a second transmission means 6 having different transmission method of the driving force which respectively transmit the driving force of the actuator to the lens unit, and a switching means 7 which switches between a first state of transmitting the driving force via the first transmission means and a second state of transmitting the driving force via the second transmission means. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an optical device that moves a lens unit by transmitting a driving force of an actuator to the lens unit.

  Recently, there are cameras that can record images in different recording modes using a single photographing optical system. Here, different recording modes include, for example, a still image shooting mode and a moving image shooting mode. A camera body having a still image shooting mode and a moving image shooting mode can be integrally formed with the shooting optical system, or a plurality of camera bodies having different recording modes can be attached to and detached from one shooting optical system. System.

  Conventionally, separate recording media such as film and video tape are used for still image shooting and for moving image shooting. However, in a digital still camera, a digital video camera, or the like provided with an image pickup device with a small pixel pitch and a high number of pixels, still images and moving images can be recorded on the same recording medium.

  However, conditions required for shooting differ between still image shooting and moving image shooting. Particularly in the focus adjustment operation, the accuracy of the in-focus position and the shortening of the focus adjustment time are required for still image shooting. Further, in moving image shooting, it is required to perform the focus adjustment operation quietly so that the driving sound in the camera body is not recorded as noise.

On the other hand, splitting the luminous flux from the photographic lens, taking one of the luminous fluxes on a silver salt film, taking a still image, and imaging the other luminous flux on the image sensor via a reduction optical system There is an optical apparatus that performs the above (for example, see Patent Document 1). In this optical apparatus, focus adjustment in photographing using an image sensor is performed by moving a reduction optical system different from the focus lens in the photographing lens.
Japanese Patent Laid-Open No. 9-113989 (paragraph number 0024, FIG. 1 etc.)

  However, in a system in which the photographing optical system is exchanged according to moving image photographing and still image photographing, workability and portability are impaired, and there is a possibility that a photographing opportunity may be missed while the photographing optical system is exchanged.

  On the other hand, in the optical apparatus proposed in Patent Document 1, it is necessary to dispose a reduction optical system so that an image obtained by dividing a light beam and re-imaged can be captured by the imaging device, so that the optical apparatus becomes large. Moreover, since the light beam is split, the amount of light decreases.

  An object of the present invention is to provide an optical apparatus capable of performing focus adjustment suitable for moving image shooting and still image shooting with a simple configuration.

  An optical apparatus according to a first invention of the present application includes a movable lens unit, an actuator that generates a driving force for driving the lens unit, a first transmission unit that transmits the driving force of the actuator to the lens unit, and The second transmission means having a different driving force transmission method from the first transmission means, the first state in which the driving force is transmitted via the first transmission means, and the driving force via the second transmission means. And switching means for switching between the second state to be transmitted.

  A second invention of the present application is an optical device used for still image shooting and moving image shooting, and a second focus lens having different characteristics regarding the focus action with respect to the first focus lens unit and the first focus lens unit. A control unit that performs focus control for driving one of the first and second lens units, and the control unit drives the first focus lens unit in focus control during still image shooting. In the focus control at the time of moving image shooting, the second focus lens unit is driven.

  According to the first invention of the present application, it is possible to select the transmission means (first or second transmission means) of the optimum transmission method according to the photographing condition, the photographing mode, and the like.

  According to the second invention of the present application, it is possible to select a focus lens unit (first or second focus lens unit) that is optimal for the focus characteristics required in moving image shooting and still image shooting.

  Examples of the present invention will be described below.

  Hereinafter, a camera system (imaging system) that is Embodiment 1 of the present invention will be described with reference to FIGS. 1 to 3.

  FIG. 1 is a block diagram showing the configuration of the camera system of this embodiment. Hereinafter, the configuration of the camera system of the present embodiment will be described.

  The camera system according to the present embodiment includes a camera body 20 including an image sensor 22 and an interchangeable lens 10 attached to the camera body 20. The lens CPU 1 in the interchangeable lens 10 and the camera CPU (control means) 21 in the camera body 20 can communicate with each other via the lens communication contact 12 and the camera communication contact 27. The lens CPU 1 controls the operation in the interchangeable lens 10.

  L1 to L4 are lens units. Specifically, the lens units L1 and L4 are fixed lens units, the lens unit L2 is a lens unit for zooming, and the lens unit L3 is a focus lens unit.

  The lens unit L2 is movable in the optical axis X direction by receiving an output from the zoom drive circuit 11 that has received a control signal from the lens CPU1. Thereby, the focal length of the photographing optical system can be changed. The focus lens unit L3 can adjust the focus of the photographing optical system by moving in the direction of the optical axis X.

  Reference numeral 4 denotes a mechanical diaphragm as a light quantity adjusting unit, which moves a plurality of diaphragm blades in a plane substantially orthogonal to the optical axis X to change the diameter of the light passage opening. The diaphragm drive circuit 8 that has received the control signal from the lens CPU 1 drives the mechanical diaphragm 4. The lens unit L1 to L4 and the mechanical aperture 4 constitute a photographing optical system L.

  The image of the subject 50 passes through the photographing optical system L in the interchangeable lens 10 and enters the image pickup device 22 in the camera body 20.

  An operation switch 2 is a switch for performing zooming, focusing, aperture value setting, switching between auto focus and manual focus, etc. by manual operation.

  Reference numeral 3 denotes a focus drive unit including a focus motor as an actuator, which is driven based on a control signal from the lens CPU1. Reference numeral 7 denotes a selection unit, which controls from the lens CPU 1 which one of the first and second transmission mechanisms 5 and 6 for transmitting the driving force from the focus driving unit 3 to the focus lens unit L3. Determine based on the signal.

  The first transmission mechanism (first transmission means) 5 is a power transmission mechanism configured by meshing a plurality of gears, and reduces the driving force from the focus motor in the focus drive unit 3 to reduce the focus lens unit. To L3.

  The second transmission mechanism (second transmission means) 6 is a power transmission mechanism having a rubber roller. In the second transmission mechanism 6, as described later, when the rubber roller (hard rubber portion) is rotated by receiving a driving force from the focus motor, the rotating member is rotated by the frictional force of the rubber roller and the rotating member (lens driving ring). It has become. The focus lens unit L3 is moved by the rotation of the rotating member.

  Of the focus driving unit 3, a rotating member that rotates by driving the focus motor is provided with a pulse generating unit, and the pulse generating unit outputs a pulse signal corresponding to the rotation of the rotating member. The lens CPU1 detects the position of the focusing lens L3 by detecting the pulse signal output from the pulse generation unit.

  A focal length detection unit 9 detects the focal length of the photographing optical system by detecting the position of the lens unit L2 for zooming. The focal length detection unit 9 detects the position of the lens unit L2 using a gray code pattern divided into 32 parts.

  The memory in the lens CPU 1 is divided into the ID of the interchangeable lens 10, focal length information, the amount of focus movement on the image sensor surface with respect to the amount of movement of the focusing lens unit L3 (hereinafter referred to as focus sensitivity), and the like. Stored for each focal length.

  The subject light that has passed through the photographing optical system L in the interchangeable lens 10 forms an image on the imaging surface (light receiving surface) of the imaging element 22. The imaging element 22 is configured by a photoelectric conversion element such as a CCD or a CMOS, and converts an optical image into an electrical signal by photoelectric conversion. The signal read from the image sensor 22 is subjected to amplification processing and A / D conversion processing, and then output to the camera CPU 21 as a digital video signal.

  In the camera system of the present embodiment, a moving image or a still image is formed using the digital video signal.

  The digital video signal is output not only to the camera CPU 21 but also to an autofocus (hereinafter referred to as AF) processing circuit 29. When a digital video signal is input to the AF processing circuit 29, a high-frequency component in image data for one screen is extracted through a high-pass filter (HPF) or the like, and arithmetic processing such as cumulative addition is performed on the high-frequency component. Done.

  Thus, an AF evaluation value corresponding to the contour component amount on the high frequency side is calculated. Then, by moving the focus lens unit L3 to a position where the AF evaluation value shows a peak, focus detection by a so-called contrast detection method can be performed. The AF evaluation value calculated by the AF processing circuit 29 is output to the camera CPU 21.

  The focus adjustment operation in the camera system of the present embodiment is performed by moving the focus lens unit L3 in the optical axis direction based on the contrast detection method and the focus sensitivity information stored in the lens CPU1. In addition, since the focus adjustment by the contrast detection method is a known technique, a detailed description is omitted.

  Reference numeral 24 denotes a release switch composed of a two-stage switch, a switch (SW1) for starting photographing preparation operations such as photometry, focus detection and focusing operation, and a switch for starting exposure to the image sensor 22. (SW2). The output signal of the release switch 24 is input to the camera CPU 21, and the camera CPU 21 performs an operation according to the input signal.

  The camera CPU 21 controls the display unit 25, performs a control operation corresponding to an input from the setting switch 26 operated to perform a shooting mode, various settings, and the like, checks the remaining capacity of the power source 28, shares power, and the like. All controls are performed. Here, on the display unit 25, for example, a moving image or a still image captured using the imaging element 22 is displayed.

  Reference numeral 23 denotes a recording circuit for recording a video signal on a recording medium detachable from the camera body 20. In the present embodiment, various buffer memories and the like are included in the camera CPU 21.

  FIG. 2 is a diagram showing a configuration including first and second transmission mechanisms.

  The DC motor 51 as the focus motor described above is fixed to the ground plate 55 by a fastening member (not shown). The ground plane 56 is fixed to the ground plane 55. A small pulley 52 is fixed to the output shaft 51b of the DC motor 51 by press-fitting.

  A rubber belt 53 transmits the rotational force of the small pulley 52 to the large pulley 54. The large pulley 54 has a gear portion 54b and a pulse plate portion 54a in which slits extending in the radial direction from the rotation axis are formed at equal intervals.

  A photo interrupter 68 generates a pulse signal corresponding to the rotation of the pulse plate portion 54a. This pulse signal is output to the lens CPU 1 via the flexible printed wiring board 57. The lens CPU 1 can detect the rotation speed and rotation speed of the DC motor 51 based on the input pal signal.

  Reference numeral 58 denotes a first gear (two-stage gear) having gear portions 58a and 58b having different numbers of teeth. The gear portion 58a meshes with the gear portion 54b of the large pulley 54. Reference numeral 59 denotes a second gear (two-stage gear) having gear portions 59a and 59b having different numbers of teeth. The gear portion 59a meshes with the gear portion 58b of the first gear 58.

  Reference numeral 60 denotes a third gear, which meshes with the gear portion 59b of the second gear 59 at the gear portion 60a. The third gear 60 is fixed to the output shaft 61 by a retaining ring 62 and can rotate with the output shaft 61. The output shaft 61 is rotatably supported by a bearing portion 55a formed on the main plate 55.

  A reduction mechanism is configured by the gear train described above, and the output torque of the DC motor 51 is increased.

  In addition, by providing the pulse plate portion 54a on the large pulley 54 located near the output shaft of the DC motor 51 in the above-described reduction mechanism, it is possible to improve the accuracy of driving the DC motor 51 (focus lens unit L3). it can. The large pulley 54 and the first gear 58 to the third gear 60 are rotatably supported at predetermined positions by the ground plate 55 and the ground plate 56.

  Reference numeral 63 denotes a selection member that is engaged with the output shaft 61. A hard rubber portion 63d that has an inclined surface with an angle with respect to the rotation axis and is elastically deformable is outsert-molded at the distal end portion of the selection member 63. A gear portion 63 a is formed at the base end portion of the selection member 63.

  A tension coil spring 65 is fixed by bonding in a state where one end side is fitted in the hole 63e of the selection member 63, and is fixed by bonding in a state where the other end side is fitted in the groove portion of the rotating ring 70.

  The rotating ring 70 fixed to the output shaft 61 is attached to the main plate 55 by a retaining ring 69, and can rotate without moving in the rotating shaft direction. For this reason, the selection member 63 rotates integrally with the output shaft 61 while being constantly urged in the direction of the arrow A.

  Reference numeral 64 denotes a switching member (a part of the selection unit 7), which is connected to a plunger (not shown) (a part of the selection unit 7), and is movable in the direction of arrow B by the operation of this plunger. Since the tip of the switching member 64 is in contact with the side surface of the recess 63b formed in the selection member 63, when the switching member 64 moves in the direction of arrow B by the operation of the plunger, the selection member 63 is correspondingly moved. Will move in the direction of arrow B.

  Reference numeral 67 denotes a lens drive ring, which has a gear portion 67a and a contact portion 67b with which the hard rubber portion 63d of the selection member 63 contacts. The lens driving ring 67 is connected to the focus lens unit L3, and moves the focus lens unit L3 in the optical axis X direction by rotating in response to the driving force from the DC motor 51.

  Here, when the switching member 64 is in the position shown in FIG. 2, the gear portion 63 a of the selection member 63 is engaged with the gear portion 67 a of the lens drive ring 67, so that the rotational force of the selection member 63 is applied to the lens drive ring 67. Communicated.

  On the other hand, when the switching member 64 is moved in the arrow B1 direction from the position shown in FIG. 2 by the operation of the plunger, the selection member 63 also moves in the arrow B1 direction against the biasing force of the tension coil spring 65. As a result, the hard rubber portion 63 d comes into contact with the contact portion 67 b of the lens driving ring 67. If the hard rubber portion 63d is brought into pressure contact with the contact portion 67b, the rotational force of the selection member 63 is transmitted to the lens drive ring 67 by the frictional force between the hard rubber portion 63d and the contact portion 67b. .

  As a result, the rotational force of the output shaft 61 can be transmitted to the lens driving ring 67 by the engagement of the gear portion 63a of the selection member 63 and the gear portion 67a of the lens driving ring 67, and the hard rubber portion 63d and the abutting contact. It can be transmitted to the lens driving ring 67 by the frictional force of the portion 67b. That is, by changing the position of the switching member 64, the power transmission method for the lens drive ring 67 can be switched between power transmission by frictional force and power transmission by meshing of the gear portion.

  Here, when the selection member 63 is moved in the direction of arrow A to switch from the transmission method using the frictional force to the transmission method using the gear, it is conceivable that the phases of the gear portion 63a and the gear portion 67a are shifted and do not mesh with each other. However, in the configuration of the present embodiment, the tension coil spring 65 always urges the selection member 63 in the direction of arrow A, so that the gear portion 67a and the gear portion 63a are in phase with each other when the DC motor 51 is driven. It becomes to mesh.

Here, the urging force Fc of the tension coil spring 65, the urging force Fg in the arrow A direction due to the contact of the hard rubber portion 63d and the contact portion 67b, and the holding force Fp of the plunger satisfy the following relational expression (1). .
1.5 × (Fc + Fg) <Fp (1)
That is, the force at which the tip of the switching member 64 holds the recess 63b of the selection member 63 is stronger than the force by which the tension coil spring 65 biases the selection member 63 in the direction of arrow A. For this reason, when the hard rubber portion 63d is brought into pressure contact with the contact portion 67b, the hard rubber portion 63d does not idle with respect to the contact portion 67b.

  Further, since the lens driving ring 67 is driven by the friction between the hard rubber portion 63d and the contact portion 67b, the driving sound generated with the rotation of the selection member 63 is generated by the meshing of the gear portion 63a and the gear portion 67a. It is smaller than the driving sound. For this reason, driving the lens drive ring 67 using the frictional force between the hard rubber portion 63d and the contact portion 67b is suitable for moving image shooting.

  On the other hand, in still image shooting, since it is necessary to control the position of the focus lens unit L3 with high accuracy, it is preferable to drive the lens driving ring 67 by meshing between the gear portion 63a and the gear portion 67a. When the lens drive ring 67 rotated in one direction is rotated in the reverse direction, the focus lens unit L3 is driven with high accuracy by driving without the backlash between the gears in the reduction mechanism described above. can do.

  In the case of driving the lens driving ring 67 using the frictional force between the hard rubber portion 63d and the contact portion 67b, there is a possibility that the slip of the hard rubber portion 63d with respect to the contact portion 67b may occur slightly. However, because of the difference in the output form of the image sensor 22, the image size is smaller in the case of moving image shooting than in the case of still image shooting. Focusing accuracy is not required. In addition, in the present embodiment, as described above, focus adjustment is performed by the contrast detection method based on the output of the image sensor 22, that is, the focus lens unit L3 is driven until the AF evaluation value reaches a peak. Even if the slip occurs, there is no problem.

  In this embodiment, by driving the plunger as described above, a power transmission method by the engagement of the gear portion 63a and the gear portion 67a and a power transmission method by the frictional force between the hard rubber portion 63d and the contact portion 67b are used. Although switching is performed, this switching may be performed manually. For example, the interchangeable lens 10 can be provided with an operation member that is operated to switch the position of the selection member 63.

  In the present embodiment, the power is transmitted to the lens driving ring 67 by the configuration using the hard rubber portion 63d, but any configuration can be used as long as the configuration reduces the lens driving sound. For example, power can be transmitted using a belt.

  FIG. 3 is a flowchart showing the photographing operation in the camera system of this embodiment, and particularly shows the control contents of the lens CPU 1 and the camera CPU 21.

  In step S01, the camera CPU 21 determines whether or not the shooting mode selected by the setting switch 26 of the camera body 20 is the moving image shooting mode. If the shooting mode is the moving image shooting mode, the process proceeds to step S02. If there is, the process proceeds to step S12.

  In step S02, the position of the selection unit 7 (selection member 63 in FIG. 2) is confirmed, and it is determined whether or not the power transmission method is a method using a frictional force between the hard rubber portion 63d and the contact portion 67b. . Specifically, the determination is made based on the position of the switching member 64.

  Here, if it is transmission using friction force, it will progress to step S03. On the other hand, if not the transmission using the frictional force, the hard rubber portion 63d is brought into contact with the contact portion 67a of the lens driving ring 67 by operating the plunger in step S11 to change the position of the selection member 63. .

  In step S03, it is determined whether or not SW1 of the release switch 24 is ON. If not, the process returns to step S01. On the other hand, if SW1 is in the ON state, the process proceeds to step S04, and the photometric operation is performed based on the video signal generated from the output of the image sensor 22.

  In step S05, the exposure time during exposure (hereinafter referred to as shutter speed) and the aperture diameter of the mechanical aperture 4 (hereinafter referred to as aperture value) are determined based on the photometric information obtained in step S04. Next, in step S06, the camera CPU 21 drives the focus lens unit L3 based on the output of the AF processing circuit 29, the lens information stored in the lens CPU 1, and the output from the focal length detection circuit 9. (Including the driving direction). Then, the camera CPU 21 transmits information regarding the driving amount of the focus lens unit L3 (for example, the number of driving pulses of the DC motor 51) to the lens CPU 1.

  In step S07, the lens CPU1 drives the DC motor 51 based on the drive amount of the focus lens unit L3 transmitted from the camera CPU21. Then, the driving force of the DC motor 51 in the focus driving unit 3 is transmitted to the lens driving ring 67 via the second transmission mechanism 6 (transmission mechanism using frictional force), and the lens driving ring 67 rotates. As a result, the focus lens unit L3 moves.

  In step S08, it is determined whether or not the photographing optical system is in focus. If it is in focus, the process proceeds to step S09. If it is not in focus, the process returns to step S06 and the remaining drive of the focus lens unit L3 is performed. Calculate the amount. That is, in this embodiment, the focus lens unit L3 is moved to a position where the AF evaluation value shows a peak value while changing the drive amount and drive direction of the focus lens unit L3 (so-called hill climbing method).

  In step S09, the camera CPU 21 determines whether or not SW2 of the release switch 24 is in an ON state. If the switch 2 is in an ON state, exposure control is performed in step S10. That is, the driving of the aperture unit 4 is controlled so that the aperture value determined in step S05 is obtained, and the shutter unit is driven at the shutter speed determined in step S05. On the other hand, if SW2 is not ON, the process returns to step S01.

  Next, the control when it is determined in step S01 that the moving image shooting mode is not set will be described. In step S12, the lens CPU 101 confirms the position of the selection unit 7 (selection member 63 in FIG. 2) and determines whether or not the power transmission method is gear transmission by the gear portions 63a and 67a. Here, if it is gear transmission, it will progress to step S13, and if that is not right, it will progress to step S21. In step S21, the gear member 63a of the selection member 63 is engaged with the gear portion 67a of the lens drive ring 67 by moving the selection member 63 by operating the plunger.

  Here, when the gear portions 63a and 67a are not in a phase in which they mesh with each other, the position of the selection member 63 does not change and only the plunger and the switching member 64 operate. After that, when the focus lens unit L3 is driven in step S17, when the gear portions 63a and 67a are in phase, the selection member 63 receives the inactive force of the tension coil spring 65, thereby meshing with the gear portion 67a ( Move in the direction of arrow A in FIG.

  In step S13, it is determined whether or not SW1 of the release switch 24 is in an ON state. If not, the process returns to step S01. If SW1 is in the ON state, the process proceeds to step S14, and the photometric operation is performed based on the video signal from the image sensor 22.

  In step S15, the shutter speed and aperture value at the time of exposure are determined based on the photometric information in step S14. Next, in step S16, the camera CPU 21 drives the focus lens unit L3 based on the output of the AF processing circuit 29, the lens information stored in the lens CPU 1, and the output from the focal length detection circuit 9. (Including the driving direction). Then, the camera CPU 21 transmits information regarding the driving amount of the focus lens unit L3 (for example, the number of driving pulses of the DC motor 51) to the lens CPU 1.

  In step S <b> 17, the lens CPU 1 drives the DC motor 51 based on the drive amount of the focus lens unit L <b> 3 transmitted from the camera CPU 21. The driving force of the DC motor 51 in the focus driving unit 3 is transmitted to the lens driving ring 67 via the first transmission mechanism 5 (transmission mechanism using the meshing of the gear portions 63a and 67a), and the lens driving ring As the lens 67 rotates, the focus lens unit L3 moves.

  In step S18, it is determined whether or not the photographing optical system is in focus. If it is in focus, the process proceeds to step S19. If it is not in focus, the process returns to step S16, and the remaining drive amount of the focus lens unit L3. Is calculated. In step S19, it is determined whether or not SW2 of the release switch 24 is in an ON state. If it is in an ON state, exposure control is performed in step S20. In this exposure control, drive control of the aperture unit 4 is performed so that the aperture value determined in step S15 is obtained, and the shutter unit is driven at the shutter speed determined in step S15. If it is determined in step 19 that SW2 is not in the ON state, the process returns to step S01.

  By performing the above-described control, the focus lens unit L3 is driven by friction transmission (power transmission by the second transmission mechanism 6) using the hard rubber portion 63d and the contact portion 67b that are unlikely to generate noise during movie shooting. be able to. Thereby, it can suppress that the drive sound of focus lens unit L3 will be recorded. Further, during still image shooting, the focus lens unit L3 is driven by gear transmission using the gear portions 63a and 67a (power transmission by the first transmission mechanism 5). In the case of still image shooting, since the driving sound of the focus lens unit L3 does not become a problem, the focus lens unit L3 is driven using the first transmission mechanism 5 to perform high-speed and high-precision focus adjustment. Can be performed.

  Next, a camera system that is Embodiment 2 of the present invention will be described with reference to FIGS. 4 is a block diagram showing the configuration of the camera system of this embodiment, and FIG. 5 is a flowchart showing the operation of the camera system of this embodiment.

  First, the configuration of the camera system of this embodiment will be described. The camera system of the present embodiment includes a camera body 120 having an image sensor 122 and an interchangeable lens 110 attached to the camera body 120. The lens CPU 101 in the interchangeable lens 110 and the camera CPU (control means) 121 in the camera body 120 exchange information via the lens communication contact 112 and the camera communication contact 127, and the lens CPU 101 operates in the interchangeable lens 110. Is controlling.

  L101 to L104 are lens units. The lens unit L104 is a fixed lens unit, the lens unit L101 is a lens unit for zooming, and the lens units L102 and L103 are focus lens units.

  The lens unit L101 for zooming receives the driving force from the zoom driving unit 111 and moves in the direction of the optical axis X, thereby changing the focal length of the photographing optical system L. The focus lens units L102 and L103 can adjust the focus of the photographing optical L by moving in the optical axis X direction.

  Reference numeral 104 denotes a mechanical aperture as a light quantity adjustment unit, which changes the aperture area (aperture diameter) of the light passage port by moving a plurality of aperture blades in a plane substantially orthogonal to the optical axis. The aperture driving unit 108 drives the mechanical aperture 104 by receiving a control signal from the lens CPU 101.

  The image of the subject 150 passes through the photographing optical system L in the interchangeable lens 110 and enters the image sensor 122 in the camera body 120.

  Reference numeral 102 denotes an operation switch which is operated to perform zooming, focusing, aperture setting by manual operation, switching between autofocus and manual focus, and the like.

  Reference numeral 103 denotes a focus selection circuit, which transmits information on the photographing mode selected by the setting switch 26 on the camera side to the lens CPU 101, and which of the focus lenses L103 of the focus lens units L102 and L103 is based on a signal from the lens CPU101. Use to select whether to perform the focus adjustment operation. That is, it is selected which of the first lens driving unit 105 and the second lens driving unit 106 is to be driven.

  The first lens driving unit 105 and the second lens driving unit 106 drive the lens units L102 and L103, respectively. These lens driving units 105 and 106 are disposed at positions close to the lens units L102 and L103, respectively.

  Here, the lens unit L102 has a greater focus sensitivity (characteristic related to the focus action) than the lens unit L103. That is, the amount of lens movement when performing focus adjustment using the lens unit L102 is smaller than the amount of lens movement when performing focus adjustment using the lens unit L103.

  Therefore, as described later, if the focus adjustment is performed using the lens unit L102 at the time of moving image shooting, the lens driving sound can be reduced as compared with the case where the focus adjustment is performed using the lens unit L103. Thereby, focus adjustment suitable for moving image shooting can be performed.

  A focal length detection circuit 109 detects the focal length by detecting the position of the zoom lens unit L102. In the present embodiment, the position of the lens unit L101 for zooming is detected by a 32-division gray code pattern. The memory in the lens CPU 101 stores the interchangeable lens ID, focal length information, focus sensitivity of the focus lens units L102 and L103, and the like for each of the divided focal lengths.

  Next, the light beam that has passed through the interchangeable lens 110 forms an image on the imaging surface of the imaging element 122. The image sensor 122 is composed of a photoelectric conversion element such as a CCD or a CMOS. The output signal of the image sensor 122 is amplified and input to the camera CPU 121 as a digital video signal.

  In the camera system of the present embodiment, a moving image and a still image are generated using the video signal. Since the components in the camera body 120 are the same as those in the first embodiment, detailed description thereof is omitted.

  FIG. 5 is a flowchart illustrating the operation of the camera system according to the second embodiment. In particular, the control contents of the lens CPU 101 and the camera CPU 121 are illustrated.

  In step S101, the camera CPU 121 determines whether or not the shooting mode selected by operating the setting switch 126 is the moving image shooting mode. If the shooting mode is the moving image shooting mode, the process proceeds to step S111. Proceed to step S102. In step S102, the lens unit L103 with low focus sensitivity is selected as the focus lens unit to be driven, and the lens knit L102 not used as the focus lens unit is moved to a predetermined position.

  In step S103, it is determined whether or not SW1 of the release switch 124 is in an ON state. If not, the process returns to step S101. If SW1 is in the ON state, the process proceeds to step S104, and a photometric operation is performed based on the video signal from the image sensor 122. In step S105, an exposure value is determined based on the photometric information in step S104.

  Next, in step S106, the camera CPU 121 drives the focus lens unit L103 based on the output from the AF processing circuit 129, the lens information stored in the lens CPU 101, and the output from the focal length detection circuit 109. (Including the driving direction). Then, the camera CPU 121 transmits information regarding the drive amount of the focus lens unit L103 (for example, the number of drive pulses of the focus motor) to the lens CPU 101.

  In step S117, the lens CPU 101 drives the focus motor in the interchangeable lens 110 based on the drive amount of the focus lens unit L103 transmitted from the camera CPU 121. As a result, the focus lens unit L103 moves.

  In step S108, the camera CPU 121 determines whether or not the photographing optical system is in focus based on the output of the AF processing circuit 129. If in focus, the process proceeds to step S109. Returning to S106, the remaining drive amount of the focus lens unit L103 is calculated.

  In step S109, it is determined whether or not SW2 of the release switch 124 is in an ON state. If the SW2 of the release switch 124 is in an ON state, normal exposure control is performed in step S110. If not, the process returns to step S101.

  Next, an operation when it is determined in step S101 that the moving image shooting mode is set will be described.

  In step S111, the focus lens unit to be driven is set to the lens unit L102 having a higher focus sensitivity than the lens unit L103, and the lens unit L103 not driven as the focus lens unit is moved to a predetermined position. In step S112, it is determined whether or not SW1 of the release switch 124 is in an ON state. If not, the process returns to step S101. On the other hand, if SW1 is in the ON state, the process proceeds to step S113, and the photometric operation is performed based on the video signal from the image sensor 122.

  In step S114, an exposure value (shutter speed or aperture value) is determined based on the photometric information obtained in step S113.

  Next, in step S115, the camera CPU 121 drives the focus lens unit L102 based on the output from the AF processing circuit 129, the lens information stored in the lens CPU 101, and the output from the focal length detection circuit 109. (Including the driving direction). Then, the camera CPU 121 transmits information regarding the driving amount of the focus lens unit L102 (for example, the number of driving pulses of the focus motor) to the lens CPU 101.

  In step S116, the lens CPU 101 drives the focus motor based on the drive amount of the focus lens unit L102 transmitted from the camera CPU 121. Thereby, the focus lens unit L102 moves.

  In step S117, the camera CPU 121 determines whether or not the photographing optical system is in focus based on the output of the AF processing circuit 129. If it is in focus, the process proceeds to step S118. Returning to S115, the remaining drive amount of the focus lens unit L102 is calculated.

  In step S118, it is determined whether or not SW2 of the release switch 124 is in an ON state. If it is in an ON state, normal exposure control is performed in step S119, and if it is not in an ON state, the process returns to step S101.

  According to the present embodiment, when taking a still image, the focus lens unit L103 having a lower focus sensitivity than the lens unit L102 is used to perform focus adjustment, so that the position control of the focus lens unit is performed with high accuracy. It becomes possible. In addition, when performing moving image shooting, the focus lens unit L102 having a higher focus sensitivity than the lens unit L103 is used to perform focus adjustment, so that the focus lens unit is driven as compared with the case where the lens unit L3 is driven as a focus lens. The movement amount of the lens can be reduced, and the driving sound of the lens can be reduced.

  In the present embodiment, the configuration in which two lens drive units are provided for the two lens units L102 and L103 has been described, but the two lens units are connected to one lens drive unit, and the selected lens unit is selected. Alternatively, the output may be switched.

  Further, there may be no difference in the focus sensitivity of the focus lens unit depending on the focal length at the time of shooting. In this case, either focus lens unit may be driven.

1 is a block diagram showing a configuration of a camera system that is Embodiment 1 of the present invention. The enlarged view which shows the transmission mechanism in the said Example 1. FIG. 6 is a flowchart showing a shooting operation in the camera system of the first embodiment. FIG. 6 is a block diagram illustrating a configuration of a camera system that is Embodiment 2 of the present invention. 9 is a flowchart showing a shooting operation in the camera system of the second embodiment.

Explanation of symbols

L3: Focus lens unit 1: Lens CPU
5: First transmission mechanism 6: Second transmission mechanism 7: Selection mechanism 21: Camera CPU

Claims (8)

A movable lens unit;
An actuator for generating a driving force for driving the lens unit;
A first transmission means for transmitting the driving force of the actuator to the lens unit, and a second transmission means for transmitting the driving force different from the first transmission means;
And switching means for switching between a first state in which the driving force is transmitted through the first transmission unit and a second state in which the driving force is transmitted through the second transmission unit. Optical equipment. An optical device used for still image shooting and movie shooting,
2. The optical system according to claim 1, further comprising a control unit that sets the switching unit to the first state during the still image shooting and sets the switching unit to the second state during the moving image shooting. machine.   3. The optical apparatus according to claim 1, wherein the second transmission unit uses a transmission method in which an operation sound is smaller than that of the first transmission unit. 4.   4. The optical apparatus according to claim 1, wherein the first transmission unit is a gear mechanism, and the second transmission unit is a friction mechanism. 5.   The optical apparatus according to claim 1, wherein the lens unit is a focus lens unit. An optical device used for still image shooting and movie shooting,
A first focus lens unit and a second focus lens unit having different characteristics relating to the focusing action with respect to the first focus lens unit;
Control means for performing focus control for driving one of the first and second focus lens units;
The control means drives the first focus lens unit in the focus control during the still image shooting, and drives the second focus lens unit in the focus control during the moving image shooting. Optical equipment.   The optical apparatus according to claim 6, wherein the second focus lens unit has a lower focus sensitivity than the first focus lens unit. An optical instrument according to any one of claims 1 to 7,
A photographing system comprising: a photographing device capable of photographing a still image and a moving image, to which the optical device is attached.

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