JP5998782B2 - Camera shake correction device - Google Patents

Description

  The present invention relates to an optical camera shake correction mechanism that prevents the occurrence of image blur by swinging a lens or an image sensor in response to an optical axis shift caused by camera shake.

  A lens shift method is known as one of optical hand movement correction mechanisms. In the lens shift method, a gyro sensor and a correction lens are provided in a lens barrel, and the correction lens is driven so as to cancel image blur based on the output of the gyro sensor, thereby preventing image blur due to camera shake. The position of the support frame on which the correction lens is mounted is controlled within a certain range (movable range) in a plane perpendicular to the optical axis by an electromagnetic actuator including a coil, a magnet, a yoke, and the like. Since the support frame can move substantially freely within the movable range, when the camera shake correction control is in the OFF state, the support frame falls downward within the movable range due to gravity, and the correction lens The center is shifted from the optical axis.

  For this reason, for example, a configuration is known in which a support frame is locked by a cam portion provided on a lock ring, and a mechanical lock mechanism is provided to fix the position of the support frame at an appropriate position. That is, when the camera shake correction control is in the off state, the center of the correction lens is fixed to the optical axis by the lock mechanism, and when the camera shake correction control is in the on state, the lock is released (see Patent Document 1).

Japanese Patent Laid-Open No. 11-119281

  By the way, when the main switch is turned on while the camera shake correction setting switch is turned on, the lock may not be released yet. For this reason, if a release operation is performed during this period, the release process is performed after the unlocking operation is completed, and thus there is a problem that the release operation is delayed. Immediately after the main switch is turned on with the camera shake correction switch turned off, the lock may be released even though the camera shake correction drive is turned off. During this time, the correction lens is not fixed. Therefore, if the release operation is performed in such a situation and the release process is started as it is, the correction lens may vibrate during shooting due to the influence of a release shock or the like, which may cause deterioration in image quality. Further, if the release process is performed after locking, the release operation is delayed.

  SUMMARY OF THE INVENTION An object of the present invention is to make it possible to take an image immediately in response to a release operation regardless of whether camera shake correction is on or off, and to reduce the influence of vibration during the release.

  The camera shake correction device according to the present invention includes a camera shake correcting unit that cancels camera shake by driving a movable unit that holds a correction lens or an image sensor, and a lock member that restricts movement of the movable unit within a movable range when locked. In a state where the camera shake correction means is on and the movement of the movable part is locked by the lock member, or in a state where the camera shake correction means is off and the movement of the movable part is not locked by the lock member. When the operation is performed, the position of the movable portion is held at the current position by the camera shake correction means.

  The camera shake correction device also includes a movable portion micro-driving means that moves the movable portion toward a center of the movable range when locked by a predetermined distance shorter than the distance to the center when the lock member is unlocked, and the movable portion. An unlocking means for moving the lock member to the unlock position after moving the distance away from the lock member may be further provided. The predetermined distance is preferably 50% or less of the distance for moving the movable part to the center. The movement of the movable part by the movable part minute driving means is executed, for example, when camera shake correction is started.

  The movable portion includes, for example, an annular frame portion, and the lock member is a lock ring that surrounds the periphery of the annular frame portion. For example, a plurality of protrusions are provided on the outer periphery of the annular frame portion, and a plurality of recesses corresponding to the plurality of protrusions are provided on the circular inner periphery of the lock ring. The lock ring is movable between a locked position and an unlocked position. At the locked position, the protrusion abuts against the circular inner periphery, and its movement is restricted, and at the unlocked position, the protrusion is disposed in the recess. Movement for blur correction is possible.

  Further, the lens barrel having the camera shake correction mechanism of the present invention includes a camera shake correcting means for canceling camera shake by driving the movable part holding the correction lens, and a lock for restricting the movement of the movable part within the movable range when locked. The movement of the movable part is locked by the lock member or the movement of the movable part is locked by the lock member, or the movement of the movable part is not locked by the lock member. When the release operation is performed, the position of the movable portion is held at the current position by the camera shake correction means.

  According to the present invention, it is possible to make it possible to perform shooting immediately in response to a release operation regardless of whether camera shake correction is on or off, and to reduce the influence of vibration during the release.

It is a block diagram which shows typically the structure of the camera of this embodiment. It is the front perspective view of the camera-shake correction mechanism of this embodiment, the front view at the time of lock release, and the front view at the time of lock. It is a figure which shows typically the movable range of the correction | amendment lens at the time of lock release and lock. It is a perspective view which shows typically the motion of the camera by camera shake, and the relationship between an X-axis and a Y-axis. It is a front view which shows the relationship between a camera main body, a correction lens, and X and Y axes. It is a block diagram of camera shake correction control executed in the lens CPU. It is a flowchart of the main program performed with camera CPU. It is a flowchart of the main program performed with lens CPU. It is a flowchart of the lock | rock initialization operation | movement performed with lens CPU. It is a flowchart of a 1 mS timer interrupt process executed by the lens CPU in the first embodiment. It is a flowchart of the center drive process performed by lens CPU. It is a flowchart of a smile drive process executed by the lens CPU. It is a schematic diagram which shows four states where the correction lens is deviated by gravity within the movable range when locked. It is a flowchart of the current position holding drive process executed by the lens CPU. It is a flowchart of camera shake correction drive processing.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a camera equipped with a camera shake correction mechanism according to the first embodiment of the present invention. In addition, in this figure, only the structure which concerns on invention is drawn typically.

  In this embodiment, the camera 10 is a digital single-lens reflex camera in which the lens barrel 12 can be attached to and detached from the camera body 11, for example. In the present embodiment, a camera shake correction mechanism 13 is provided in the lens barrel 12. That is, the camera shake correction mechanism 13 including the correction lens 14 for shake correction is arranged between the imaging lenses 15A and 15B. Light incident from the imaging lens 15A is guided along the optical axis L to the imaging element 16 in the camera body 11 through the correction lens 14 and the imaging lens 15B, and forms an image.

  A camera CPU 17 and a lens CPU 18 are provided in the camera body 11 and the lens barrel 12, respectively. The camera CPU 17 is connected to a main switch 19, a photometric switch 20, and a release switch 21, and is connected to the lens CPU 18 through a plurality of electrodes of a lens mount (not shown) together with a power supply line and a ground. The camera CPU 17 performs various controls of the entire camera, and is connected to various other devices.

  The lens barrel 12 is provided with a camera shake correction switch 22 for setting on / off of camera shake correction control, and is connected to the lens CPU 18. Further, in the lens barrel 12, angular velocity sensors 23X and 23Y for detecting rotational angular velocities around Y and X axes along the horizontal axis and vertical axis of the camera perpendicular to the optical axis L are provided, and the angular velocity sensors 23X and 23Y are provided. The signal detected at is input to the lens CPU 18. When camera shake correction control is on, the lens CPU 18 moves the correction lens 14 to cancel camera shake based on the angular velocity around each axis detected by the angular velocity sensors 23X and 23Y and lens information such as the focal length. The target position in the power X and Y axis directions is calculated.

  For example, the correction lens 14 is driven by electromagnetic interaction between a coil (not shown) provided in a movable part that holds the correction lens 14 and a yoke provided in a fixed part fixed to the lens barrel 12, to the coil. The current supply is controlled by the X direction drive control unit 24X and the Y direction drive control unit 24Y. The movable part that holds the correction lens 14 is provided with position sensors 25X and 25Y using, for example, a Hall element, and the position of the correction lens 14 is detected and fed back to the lens CPU 18. That is, the lens CPU 18 calculates the current supply amount to the coil from the target position of the correction lens 14 calculated based on the signals of the angular velocity sensors 23X and 23Y and the position of the current correction lens 14 obtained from the position sensors 25X and 25Y. And output to the X direction drive control unit 24X and the Y direction drive control unit 24Y.

  The camera shake correction mechanism 13 is provided with a mechanical lock mechanism 26, which will be described later, and a lock detection sensor 26S for detecting the locked state. The lock mechanism 26 is a mechanism for maintaining the center of the correction lens 14 on the optical axis L. The lock mechanism 26 is controlled by the lock ring control unit 27 based on a command from the lens CPU 18, and the current lock state is set by the lock detection sensor 26S. Is notified to the lens CPU 18.

  The communication port of the lens CPU 18 and the communication port of the camera CPU 17 are connected through the lens mount electrodes as described above, and data communication is performed between them as will be described later.

  FIGS. 2A to 2C are external views of the camera shake correction mechanism 13 of the present embodiment. FIG. 2A is a front perspective view, and FIG. 2B is a front view when unlocking. FIG. 2 (c) is a front view when locked.

  As shown in the figure, the correction lens 14 is held at its approximate center by a movable portion 28 having an annular frame. For example, four protrusions 28P extending outward in the radial direction are provided on the outer peripheral portion of the annular frame of the movable portion 28 at substantially equal intervals along the outer periphery. An annular lock ring 30 is disposed around the annular frame of the movable portion 28 so as to surround the annular frame, and an annular clearance 29 is provided between the lock ring 30 and the annular frame.

  The inner diameter of the lock ring 30 is such that each protrusion 28P of the movable portion 28 abuts on the inner periphery of the lock ring 30 except for tolerances, and the number of recesses 30P corresponding to the protrusions 28P is formed on the inner periphery. It is formed at substantially equal intervals along. As will be described later, the concave portion 30P defines the movable range of the correction lens 14 in camera shake correction in cooperation with the protrusion 28P.

  The lock ring 30 is accommodated in a casing 31 that has a substantially cylindrical appearance, and can be rotated around the optical axis in the casing (fixed portion) 31. The rotation of the lock ring 30 is performed by, for example, a rack and pinion mechanism provided on the outer periphery of the lock ring 30. That is, a rack portion 30 </ b> R is provided on the outer peripheral portion of the lock ring 30 and meshed with a pinion 32 provided on the casing 31 side, and the pinion 32 is driven by a stepping motor (not shown) fixed in the casing 31. The

  Further, notches 30A and 30B for detecting the locked state from the rotational position of the lock ring 30 are provided on the outer periphery of the lock ring 30, and the photo interrupter that cooperates with the notches 30A and 30B is provided in the casing 31. (Lock detection sensor) 26S is provided. That is, when the lock is released, light is detected in the photo interrupter 26S through the notch 30A as shown in FIG. 2B, and when locked, the light is detected through the notch 30B as shown in FIG. 2C.

  Further, the movable portion 28 is provided with a plurality of flat plate portions 28A extending radially outward from the annular frame, and a coil or the like for driving the movable portion 28 is mounted thereon. The flat plate portion 28A is supported in the casing 31 by a bearing (not shown) in the front and rear thereof, and movement in the optical axis direction is restricted.

  Next, the movable range of the correction lens 14 in this embodiment will be described with reference to FIGS. FIGS. 3A and 3B are diagrams schematically illustrating the movable range of the correction lens 14 when unlocked and locked.

  When the lock shown in FIG. 2B is released, the lock ring 30 is arranged so that the protrusions 28P of the movable portion 28 are positioned in the recesses 30P. At this time, the movement of the movable portion 28 is regulated by the protrusion 28P coming into contact with the side wall of the concave portion 30P, and the movable range of the correction lens 14 is a rectangular region shaded in FIG. ) 33. On the other hand, at the time of locking in FIG. 2C, the lock ring 30 is rotated clockwise from the position in FIG. 2B, and each projection 28P is brought into contact with the arcuate inner peripheral surface of the lock ring 30. . Thereby, the movement of the movable portion 28 in the vertical and horizontal directions is restricted, and the center of the correction lens 14 is fixed so as to coincide with the optical axis L.

  However, since there is a tolerance between the projection 28P and the arcuate inner peripheral surface of the lock ring 30, the correction lens 14 actually has an optical axis as shown in FIG. It can move within a circular shaded area (movable range when locked) 34 centered on L.

  With reference to FIGS. 4 to 6, the camera shake correction process of the present embodiment will be described in more detail. 4 is a perspective view schematically showing the relationship between camera movement due to camera shake and the X and Y axes, and FIG. 5 is a front view showing the relationship between the camera body 11, the correction lens 14, and the X and Y axes. is there.

  As shown in FIG. 4, in shooting with a camera, image blur that moves in the horizontal direction (X-axis direction) occurs due to rotation (yaw) around the vertical axis (Y-axis), and rotation around the horizontal axis ( The image blur that moves in the vertical direction (Y-axis direction) occurs depending on the pitch. Therefore, the amount of shift in the X-axis direction of the correction lens 14 for canceling image blur in the X-axis direction is determined by detecting the rotational motion around the Y-axis, and the rotational motion around the X-axis is detected. A shift amount in the Y-axis direction of the correction lens 14 for canceling image blur in the Y-axis direction is determined.

  FIG. 6 is a block diagram of camera shake correction control executed in the lens CPU 18, and the correction process is executed as an interrupt process at intervals of a predetermined time (for example, 1 mS), for example.

Analog angular velocity signals around the Y axis and X axis obtained by the gyros of the angular velocity sensors 23X and 23Y are input to the A / D ports (A / D1, A / D2) of the lens CPU 18, and the A / D calculation unit It is converted into a digital signal in 35X and 35Y. The angular velocities around the Y axis and the X axis are integrated by the angle calculators 36X and 36Y, and the rotation angles (yaw angle θ _Y and pitch angle θ _Y ) around the Y axis and the X axis are calculated. In the lens drive position calculation units 37X and 37Y, the correction lens 14 in the X direction and the Y direction for canceling image blur based on the lens information 38 such as the yaw angle, the pitch angle, and the focal length f stored in the memory. Is calculated.

  When the camera shake correction switch 22 input from the port 4 is in the ON state, the control unit 39 drives the drive position X in the X axis direction and the drive position Y in the Y axis direction calculated by the lens drive position calculation units 37X and 37Y. Is the target position of the correction lens 14, the drive position X, the drive position Y and the current position X of the correction lens 14, and the deviation of the current position Y are calculated, and for example, processing such as PID calculation is performed on the automatic control calculation unit 40 X , 40Y. Outputs from the automatic control calculation units 40X and 40Y are output to the X direction drive control unit 24X and the Y direction drive control unit 24Y through the ports 1 and 2, and the X direction coils 41X and Y provided in the camera shake correction mechanism 13 are output. The current supplied to the direction coil 41Y is controlled.

  The position of the movable unit 28, that is, the current position of the correction lens 14 in the X-axis and Y-axis directions is determined based on signals from the hall sensors (position sensors) 25X and 25Y, the X-direction drive control unit 24X and the Y-direction drive control unit 24Y. And is input to the lens CPU 18 through the A / D port (A / D3, A / D4) as the current X position signal and Y position signal, and the current position X as a digital signal in the A / D calculation units 43X and 43Y. The current position Y is converted and fed back as described above. Thus, when the camera shake correction switch 22 is turned on, the target drive position of the correction lens 14 is calculated based on the outputs of the angular velocity sensors 23X and 23Y, and the correction lens 14 is set to the X axis, based on the target value. Driven in the Y-axis direction.

  The lens CPU 18 drives the lock motor 44 such as a stepping motor through the lock ring control unit (driver) 27 connected to the port 3 based on the on / off state of the camera shake correction switch 22 to rotate the lock ring 30. Move. That is, the position is switched between the unlocked position (FIG. 2B) and the locked position (FIG. 2C). Whether the lock ring 30 has reached the unlocked position or the locked position is detected by a photo interrupter (lock detection sensor) 26S.

  Next, the main flow executed by the camera CPU 17 and the lens CPU 18 will be described with reference to FIG. 1, FIG. 6, FIG. 7, and FIG. The flow of FIGS. 7 and 8 is started when the main switch 19 provided in the camera body 11 is turned on. Here, it is assumed that the lens barrel 12 is attached to the camera body 11.

  FIG. 7 is a flowchart on the camera CPU 17 side. In step S100, it is determined whether or not the release switch 21 is turned on. If the release switch 21 is not turned on, communication with the lens CPU 18 is started in step S102, and a lock initialization process is requested to the lens CPU 18. On the other hand, when the release switch 21 is turned on (during direct release), communication with the lens CPU 18 is started in step S132, and the lens CPU 18 is notified that the second release process (release 2) is to be executed. Then, the process jumps to a release process after step S122 described later.

  In step S104, it is determined whether or not the photometric switch 20 is turned on, and this process is repeated until the photometric switch 20 is turned on. If it is determined that the photometric switch 20 is turned on, in step S106, communication with the lens CPU 18 is started, and the lens CPU 18 is notified that a through image is displayed.

  In steps S108 to S116, a through image is captured and displayed. That is, in step S108, AE processing is performed, and in step S110, AF processing is performed. In step S112, charge accumulation in the image pickup device (CCD) 16 starts under the focus position set in step S110 and the exposure determined in step S108. Is done. In step S114, for example, field reading of the pixel signal accumulated in the image sensor (CCD) 16 is performed and output as an image signal. In step S116, the output image signal is output to a monitor (not shown) and a through image is displayed.

  Next, in step S118, it is determined whether or not the release switch 21 is turned on. If the release switch 21 is not turned on, the process jumps to step S130. If the release switch 21 is turned on, communication with the lens CPU 18 is started in step S120, and the first release process (release 1) is performed. ) Is notified to the lens CPU 18. In steps S122 to S128, still image shooting is executed. That is, in step S122, charge accumulation in the image sensor (CCD) 16 is started under the focus position set in step S110 and the exposure determined in step S108, and the charge is accumulated in the image sensor (CCD) 16 in step S124. For example, all pixels are read out of electric charges. In step S126, the output image signal is stored in a non-volatile video memory (not shown) in step S126, and the image is displayed on a monitor (not shown) in step S128.

  Next, in step S130, it is determined whether or not the photometric switch 20 is turned on. If it is determined that the photometric switch 20 is turned on, the process returns to step S106. If it is determined that the photometric switch 20 is not turned on, the process returns to step S102 and the same process is repeated. The above processing is repeated until the main switch 19 of the camera body 11 is turned off or until the camera shifts to the sleep mode.

  FIG. 8 is a flowchart on the lens CPU 18 side. In steps S200 and S202, the status register is initialized. Here, a flag SR indicating the state of camera shake correction control (camera shake correction status) is initialized in step S200, and a flag RLS indicating the release state (release status) is initialized in step S202. That is, SR = RLS = 0 is set. The flag SR has three states, SR = 0 indicates that processing (initial operation) for locking by the lock ring 30 has been executed, SR = 1 indicates that camera shake correction is in an off state, SR = 2 indicates that the camera shake correction is on. The flag RLS takes two states, RLS = 0 indicates a state where a through image is displayed, and RLS = 1 indicates that a release operation is being performed.

  When the initialization of the flags SR and RLS is completed, in step S204, it is determined whether or not there is a communication request from the camera CPU 17, and this determination is repeated until there is a communication request from the camera CPU 17. When the lens CPU 18 detects a communication request from the camera CPU 17, in steps S 206, S 208, S 210, and S 212, the communication from the camera CPU 17 is a lock initialization request (lock operation request by the lock ring 30), or the camera body 11 is through. It is determined whether the image display is to be notified, the camera main body 11 is to notify the first release operation, or the second release operation is to be notified. .

  In the case of a lock initialization request, the lock initialization operation shown in the flowchart of FIG. 9 is executed in step S214. As shown in FIG. 9, in the lock initialization operation, first, in step S300, a center driving process for matching the correction lens 14 with the optical axis is executed. That is, as shown in the flowchart of FIG. 11, in the center driving process, in step S500, the current position information of the correction lens 14 is detected based on the outputs of the hall sensors 25X and 25Y (FIG. 6), and the control is performed in step S502. The drive position (X, Y), which is the target position of the correction lens 14 in the unit 39, is set to (0, 0) corresponding to the center of the optical axis and the movable ranges 33, 34 (see FIG. 3). Thereafter, in steps S504 and S506, calculation for automatic control is performed based on the current position and the target position, and based on the calculation result, the camera shake correction mechanism 13 is driven to move the correction lens 14 to the center position (0, 0). Move to.

  Next, in step S302, the lock motor 44 is driven to rotate the lock ring 30 to the lock position. In step S304, power supply to the coils 41X and 41Y constituting the electromagnetic actuator is stopped, and driving of the correction lens 14 is stopped. Thereafter, in step S306, the flag SR indicating the camera shake correction status is set to “0” indicating that the lock initial operation has been executed (SR = 0), and the lock initialization operation ends.

  On the other hand, if it is determined in step S208 that the communication from the camera CPU 17 notifies the display of the through image, the flag RLS indicating the release status indicates that the through image is being displayed in step S216. Set to “0” (RLS = 0). If it is determined in step S210 that the communication from the camera CPU 17 notifies that the first release operation is to be performed, the flag RLS indicating the release status is in the release operation in step S218. Is set to “1” (RLS = 1). If it is determined in step S212 that the communication from the camera CPU 17 notifies that the second release operation is to be performed, the flag SR indicating the camera shake correction status is set in step S220 and the camera shake correction is performed. The flag RLS indicating the release status is set to “1” indicating that the release operation is being performed (RLS = 1). Note that while the lens CPU 18 is powered on, the processes in steps S204 to S212 are repeated.

  In the lens CPU 18, a timer interrupt shown in the flowchart of FIG. 10 is generated at a cycle of 1 ms. Hereinafter, the 1 ms timer interrupt processing according to the present embodiment will be described with reference to FIGS. 2, 6, 10, and 11.

  In the 1 ms timer interrupt process, first, in step S400, it is determined whether or not the flag RLS = 1, that is, whether or not the current status is a release operation. If RLS ≠ 1, that is, if the release operation is not in progress, the on / off state of the camera shake correction switch 22 is detected in step S402, and it is determined whether or not the switch is on.

  If the camera shake correction switch 22 is in the OFF state, whether or not the flag SR = 1 or SR = 0 in step S404, that is, whether the current status is the camera shake correction OFF state or the lock initialization operation has been completed. It is determined whether or not it is in a state. When SR.noteq.1 and SR.noteq.0, that is, when the current status does not indicate the camera shake correction OFF state and the lock initialization process is not performed, the center drive process shown in the flowchart of FIG. 11 is performed in step S406. In step S408, the lock motor 44 is driven to rotate the lock ring 30 (FIG. 2) to the lock position to ensure the lock state. For example, this corresponds to a case where the power is turned off while the camera shake correction switch 22 is turned on and the status is maintained at SR = 2 when the camera is used last time. In other words, the correction lens 14 is not locked although the camera shake correction is currently turned off, and thus the correction lens 14 is locked in this processing.

  In step S410, the flag SR indicating the camera shake correction status is set to “1” indicating that the camera shake correction is off (SR = 1). In step S412, the power supply to the coil of the camera shake correction mechanism 13 (FIG. 6) is stopped, the camera shake correction drive is turned off, and the current timer interrupt process ends. On the other hand, when SR = 1 or SR = 0 in step S404, the timer interrupt process is immediately terminated.

  On the other hand, if it is determined in step S402 that the camera shake correction switch 22 is on, it is determined in step S414 whether or not the flag SR = 2 indicating the camera shake correction status is set. When SR = 2, it indicates that camera shake correction has already been performed, so the process jumps to step S422, continues the camera shake correction drive process, and ends this timer interrupt process. When SR ≠ 2, since the camera shake correction process is in the off state and the lock ring 30 is in the locked state, the correction lens 14 is finely driven (described later) in step S416, and the lock ring 30 is rotated in step S418. To make it unlocked. Then, after setting the camera shake correction status flag SR to “2” (camera shake correction on) in step S420, the camera shake correction process is started in step S422, and this timer interruption process is ended.

  When the release status flag RLS = 1 in step S400, that is, when it is determined that the release operation is being performed, the on / off state of the camera shake correction switch 22 is detected in step S423, and the switch is in the on state. It is determined whether or not there is. If the camera shake correction switch 22 is in the OFF state, it is determined in step S424 whether SR = 1 (the camera shake correction status is OFF). If SR = 1, that is, if the camera shake correction status is in the OFF state, step S424 is performed. In S427, a current position holding drive process, which will be described later, is performed, and this timer interrupt process ends. If SR ≠ 1, that is, if it is determined that the camera shake correction status remains on, the camera shake correction status flag SR is changed to “1” indicating OFF in step S428, and in step S430. The camera shake correction drive is turned off, and this timer interrupt process is terminated.

  On the other hand, if it is determined in step S423 that the camera shake correction switch 22 is on, it is determined in step S425 whether SR = 2 (camera shake correction status is on). If SR = 2, the camera shake correction drive process is continued in step S422, and the timer interrupt process is terminated. On the other hand, if it is determined that SR ≠ 2, that is, that the camera shake correction status is in the OFF state, in step S427, a current position holding drive process described later is performed, and this timer interrupt process ends.

  Next, the minute driving process in step S416 (FIG. 10) will be described with reference to FIG. 2, FIG. 3, FIG. 6, and FIG. FIG. 12 is a flowchart of the minute driving process in step S416.

  When the lock ring 30 is in the locked position (FIG. 3A), the four protrusions 28P provided on the annular frame of the movable portion 28 abut against the arc-shaped inner peripheral surface of the lock ring 30. Since there is a tolerance, the correction lens 14 is movable within the movable range 34 when locked as shown in FIG. Therefore, when the camera shake correction is turned off, the correction lens 14 falls in the direction of gravity, and the protrusion 28P is in contact with the lock ring 30. Therefore, when releasing the lock, in order to eliminate the frictional resistance due to the contact of the protrusion 28P, it is necessary to separate the protrusion 28P of the movable portion 28 from the lock ring 30 as in the lock initialization operation. However, if the center drive process (FIG. 11) is performed in the same manner as the lock initialization operation process and the correction lens 14 is moved to the center of the movable regions 33 and 34, the movement time becomes longer and the unlock time becomes longer. .

Therefore, in this embodiment, instead of the center driving process of FIG. 11, a minute driving process of the correction lens 14 (movable part 28) is performed in step S416. In the minute driving process, first, in step S600, the current positions X and Y of the correction lens 14 are acquired based on the outputs of the hall sensors 25X and 25Y. In step S602, the driving position X, Y of the correction lens 14 is calculated by the following equation in the control unit 39 and set as the target position.
Drive position X = current position X × (1−α)
Drive position Y = current position Y × (1-β)

  Note that α and β may be values less than 1, but are, for example, 0.5 or less, and preferably about 0.05 to 0.2. That is, the minute drive amounts ΔX and ΔY in the X-axis and Y-axis directions from the current positions X and Y are ΔX = − (current position X × α) and ΔY = − (current position Y × β), respectively. In this embodiment, for example, α = β = 0.1. That is, in the minute driving process of the present embodiment, the center of the movable regions 33 and 34 (that is, the optical axis) is the coordinate origin, the position of the correction lens 14 is the lens center, and the correction lens 14 is the current position coordinate X, Y. 10% of the distance, and moves in the -X and -Y axis directions. This corresponds to a slight movement of about 10% of the deviation amount toward the center of the correction lens 14 that has fallen in the direction of gravity.

  In step S604, automatic control calculation is performed based on the set drive positions X and Y. In step S606, the movable unit 28 is driven and the correction lens 14 is moved to the drive positions X and Y, and this minute driving process is performed. Ends.

  Note that, as shown in FIGS. 13A to 13D, the direction in which the correction lens 14 is biased due to gravity varies depending on the tilted direction of the camera. However, if the above formulas for determining the drive positions X and Y are used, the same simple formula can be used in any case regardless of the direction of gravity. In FIG. 13, a point P indicates the center position of the biased correction lens 14, and corresponds to the current positions X and Y in each case.

  Next, the current position holding drive process executed in step S427 of FIG. 10 will be described with reference to FIG. The current position holding drive process is a state in which the lock initialization operation is not processed (see step S132 in FIG. 7), and the camera shake correction switch 22 is turned off and the camera shake correction status is turned off (SR = 1). This is executed when a release operation is performed in a state where the shake switch is on and the camera shake correction status is off (SR ≠ 2) (the camera shake correction is not executed). That is, in this process, the release switch 21 is turned on when the camera shake correction switch 22 is turned on but not yet unlocked, or when the camera shake compensation switch 22 is turned off but unlocked. This is executed when the switch is turned on (when shooting is performed in a state where the lock state does not match the actual image stabilization setting).

  Therefore, in the present embodiment, shooting is performed by electromagnetically locking the position of the correction lens 14 to the current position using the camera shake correction mechanism without matching the locked state of the correction lens 14 to the actual setting of camera shake correction. Do. That is, in step S700, the current positions X and Y of the correction lens 14 are acquired based on the signals from the hall sensors 25X and 25Y, and the drive positions X and Y set by the control unit 39 in step S702 are set to the current positions X and Y. To do. In step S704, automatic control calculation is performed based on the set drive positions X and Y. In step S706, the camera shake correction mechanism 13 is driven based on the calculation. That is, the correction lens 14 is electromagnetically locked at the current position. In the present embodiment, this processing is executed when the release switch 21 is turned on, but it is also possible to perform this processing when the release button is pressed halfway and the photometry switch is turned on. . The lock state is changed after the release operation is completed.

  Next, the camera shake correction drive process executed in step S422 in FIG. 10 will be described with reference to FIGS.

  In the camera shake correction driving process, first, in step S800, angular velocity signals around the Y and X axes are acquired from the angular velocity sensors (gyros) 23X and 23Y, and in step S802, rotation angles around the Y and X axes are calculated ( Angle calculation unit 36X, 36Y). In step S804, drive positions X and Y are calculated from the rotation angle calculated in step S802, the focal length f of the lens, and the like (lens drive position calculation units 37X and 37Y; control unit 39). In step S806, the current position of the correction lens 14 is acquired based on the signals from the hall sensors 25X and 25Y (X and Y direction drive control units 24X and 24Y), and feedback with the drive positions X and Y in the automatic control calculation in step S808. The operation amount is calculated from the deviation of the current position (automatic control calculation units 40X and 40Y). Based on the operation amount, power is supplied to the X and Y direction coils 41X and 41Y to drive the camera shake correction mechanism 13 (X and Y direction drive control units 24X and 24Y).

  As described above, according to the first embodiment, the camera shake correction setting switch is turned on but the lock is not yet released, or the camera shake correction switch is turned off but the lock is released. Even in this case, it is possible to take a picture immediately in response to the release operation, to prevent the correction lens from vibrating, and to prevent deterioration of the image quality.

  In the configuration of the first embodiment, since the movable part is not supported by the fixed part by an elastic support member such as an elastic body, camera shake correction can be driven more efficiently. On the other hand, in such a configuration, since the movable part is not supported at all by the elastic support member, when the camera shake correction is in the off state, all the dead weights of the movable part including the correction lens are locked via the contact part (protrusion). Contact with the lock ring), it becomes an obstacle when unlocking. However, in the first embodiment, even when the mechanical lock mechanism is released, the movable part is separated from the lock mechanism (lock ring) by a minute driving process, so that an excessive frictional force is not applied when the lock is released and the lock is easily performed. Can be released. Further, in this embodiment, since the correction lens is moved only slightly by the minute driving process, it is possible to shorten the time required to start the rotation of the lock mechanism (lock ring), and it is possible to release the lock quickly.

  Further, in this embodiment, the minute movement amount can be calculated by a simple formula, and the correction lens is finely driven using only the configuration of the conventional camera shake correction mechanism without using a case and a gravity sensor. be able to. In addition, this embodiment is particularly effective when the friction with the lock ring (lock member) due to the weight of the movable part is large.

  Although the present embodiment has been described by taking an example of application to a lens shift type camera shake correction mechanism, the present invention can also be applied to a camera shake correction mechanism employing an image sensor shift system. The present invention can also be applied to a mirrorless camera, a camera that is not of the interchangeable lens type, and a camera that is not provided with an image display monitor and has only a finder. For example, in the configuration of only the finder, the processing from step S108 to step S116 is not performed, and in step S106, for example, the fact that the photometric switch is turned on is notified. In this embodiment, a digital camera has been described as an example, but the present invention can also be applied to a silver salt camera.

  In this embodiment, the lock ring is used as the lock member, but the present invention can also be applied to other lock mechanisms such as a configuration in which a pin as a lock member is inserted into a hole provided in the movable portion.

DESCRIPTION OF SYMBOLS 10 Camera 13 Camera shake correction mechanism 14 Correction lens 16 Image sensor 17 Camera CPU
18 Lens CPU
19 Main switch 21 Release switch 22 Camera shake correction switch 23X, 23Y Angular velocity sensor 24X, 24Y Drive control unit 25X, 25Y Position sensor 26 Lock mechanism 26S Lock detection sensor 28 Movable part 28P Protrusion 30 Lock ring 30A, 30B Notch 30P Recess 30R Rack part 32 pinion

Claims (6)

Camera shake correction means for driving a movable portion holding a correction lens or an image sensor to cancel out camera shake;
A locking member that regulates the movement of the movable part within a movable range when locked,
The state in which the camera shake correction means is on and the movement of the movable part is locked by the lock member, or the movement of the movable part is not locked by the lock member in the state in which the camera shake correction means is off. When a release operation is performed in a state, the position of the movable portion is held at the current position by the camera shake correction means.   When unlocking by the locking member, the movable part moves toward the center of the movable range at the time of locking, a movable part fine driving means that moves a predetermined distance shorter than the distance to the center, and moves the movable part by the predetermined distance. The camera shake correction apparatus according to claim 1, further comprising: a lock release unit that moves the lock member to a lock release position after the lock member is separated from and brought into contact with the lock member.   The camera shake correction apparatus according to claim 2, wherein the predetermined distance is 50% or less of a distance for moving the movable portion to the center.   4. The camera shake correction apparatus according to claim 2, wherein the movement of the movable part by the movable part micro-driving unit is executed when camera shake correction is started. 5. .   The movable portion includes an annular frame portion, and the lock member is a lock ring that surrounds the periphery of the annular frame portion, and a plurality of protrusions are provided on an outer peripheral portion of the annular frame portion, and the lock ring has a circular shape. A plurality of recesses corresponding to the plurality of protrusions are provided in the inner peripheral portion, and the lock ring is movable between a lock position and a lock release position, and the protrusion is the circular inner peripheral portion in the lock position. 5. The movement is restricted by being in contact with the movement, and the protrusions are respectively disposed in the recesses at the unlocked position to enable movement for camera shake correction. The camera shake correction device according to the item. Camera shake correction means for driving the movable part holding the correction lens to cancel camera shake;
A locking member that regulates the movement of the movable part within a movable range when locked,
The state in which the camera shake correction means is on and the movement of the movable part is locked by the lock member, or the movement of the movable part is not locked by the lock member in the state in which the camera shake correction means is off. When a release operation is performed in the state, the camera shake correction unit holds the position of the movable portion at the current position.

Images