JP2009300879A - Shake correction device and photographing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shake correction device or the like suitably performing drive control of an optical component correcting image blur. <P>SOLUTION: The shake correction device includes the optical component 32b provided to be movable, drive sections 48 and 50 driving the optical component in order to correct the image blur, and a control part 75 controlling the drive sections to perform first control so that the optical component may be driven to the side of a center of control 112 of the optical component, and controlling the drive sections so that the first control may be inhibited according to photographing time Te when photography is started. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a shake correction apparatus and a photographing apparatus.

  As an imaging apparatus such as a camera, an imaging apparatus including a shake correction apparatus that corrects image blur caused by so-called “hand shake” by a photographer has been proposed. As a shake correction apparatus that corrects image blur, an apparatus that drives an image blur correction optical system by an electromagnetic actuator typified by, for example, a VCM (Voice Coil Motor) is known.

  However, in a photographing apparatus equipped with a shake correction device that drives an image blur correction optical system by an electromagnetic actuator or the like, the image blur correction optical system falls in the direction of gravity when the actuator is shielded from energization, which adversely affects the appearance of the viewfinder. There was a case.

  As a conventional technique for solving such a problem, for example, an imaging apparatus including a shake correction apparatus having a lock mechanism that locks an image blur correction optical system is known (see Patent Document 1).

  However, the shake correction apparatus having the lock mechanism has a problem that the number of parts increases and the structure becomes complicated.

On the other hand, the shake correction apparatus according to the prior art, which does not have a lock mechanism in particular, requires time to place (centering) the image blur correction optical system at a position suitable for the shooting operation. In some cases, the image blur correction optical system cannot be disposed at a suitable position at the start of the operation. In addition, the image blur correction optical system continues the centering operation during the exposure operation, and the image blur correction optical system moves unrelated to the shake correction, so that the photographed image is shaken. Had.
JP 2003-241247 A

  The present invention has been made in view of such circumstances, and provides a shake correction apparatus and an imaging apparatus that can suitably perform drive control of an optical component that corrects image blur.

In order to solve the above-described problem, a shake correction apparatus according to the present invention includes:
An optical component (32b) movably provided;
A drive unit (48, 50) for driving the optical component to correct image blur;
The drive unit is caused to perform a first control so that the optical component is driven to the control center side (112) of the optical component, and the first part corresponds to a photographing time (Te) at which photographing is started. And a control unit (75) for controlling the drive unit so as to inhibit the control.

  Further, for example, the control unit may control the optical component so as to correct image blur when the first control is prohibited.

  For example, the shake correction apparatus according to the present invention may include a detection unit (85) that detects the shooting time based on an operation of the operation unit (82) for performing a shooting operation.

  For example, the control unit may prohibit the first control at a predetermined time (Td) before the photographing time.

  In addition, for example, when the control unit determines that the optical component does not reach the control center by the photographing time, the control unit prohibits the driving of the optical component toward the control center before the photographing time. The drive unit may be controlled.

Further, for example, the shake correction apparatus according to the present invention has a storage unit that stores a time from the operation of the operation unit to the shooting time,
The detection unit may detect the photographing time using information in the storage unit.

  Further, for example, the control unit may be configured such that the speed of the optical component after the operation of the operation unit is greater than the speed of the optical component before the operation of the operation unit. May be controlled.

An imaging apparatus according to the present invention includes a shake correction apparatus described in any of the above,
An operation unit for performing a photographing operation.

Further, for example, the photographing apparatus according to the present invention has a blur correction stop operation unit that stops the image blur correction by the drive unit,
The control unit holds the optical component in the vicinity of the position (114) of the optical component when the first control is prohibited when the correction of the image blur is stopped by the blur correction stop operation unit. You may control to do.

In addition, for example, the photographing apparatus according to the present invention includes a storage unit that stores information regarding the position of the optical component that has good optical characteristics,
The control unit may perform control with the position of the optical component stored in the storage unit where the optical characteristics are favorable as the control center.

  In the above description, in order to explain the present invention in an easy-to-understand manner, the description is made in association with the reference numerals of the drawings showing the embodiments. However, the present invention is not limited to this. The configuration of the embodiment described later may be improved as appropriate, or at least a part of the configuration may be replaced with another component. Further, the configuration requirements that are not particularly limited with respect to the arrangement are not limited to the arrangement disclosed in the embodiment, and can be arranged at a position where the function can be achieved.

Hereinafter, the present invention will be described based on embodiments shown in the drawings.
FIG. 1 is a cross-sectional view showing a camera in which a shake correction apparatus according to an embodiment of the present invention is incorporated.
FIG. 2 is a block diagram showing an outline of control of the shake correction apparatus in the camera shown in FIG.
3 is an enlarged sectional view of a shake correction mechanism provided in the lens barrel shown in FIG.
4 is an exploded perspective view of a shake correction mechanism provided in the lens barrel shown in FIG.
FIG. 5 is a graph showing an example of a correction lens target position signal output from the arithmetic unit of the shake correction apparatus according to the embodiment of the present invention;
FIG. 6 is a flowchart showing a series of processes performed when controlling the voice coil motor in the arithmetic unit of the shake correction apparatus according to the embodiment of the present invention.
First embodiment

  FIG. 1 is a cross-sectional view showing a digital single-lens reflex camera incorporating a shake correction apparatus according to an embodiment of the present invention. The camera has a lens barrel 12 and a camera body 10. The lens barrel 12 has a photographing optical system 26 for guiding subject light to the camera body 10 and is detachably attached to the camera body 10.

  In the present embodiment, description will be made using the digital single-lens reflex camera shown in FIG. 1. However, the photographing apparatus provided with the shake correction device according to the present invention is not limited to the digital single-lens reflex camera, and other film-type cameras and the like. It may be a photographing apparatus. In the present embodiment, description will be given with the X axis, Y axis, and Z axis set as shown in FIG. That is, the direction from the image sensor 24 to the photographing optical system 26 is the positive direction of the Z axis, the direction from the quick return mirror 16 to the pentaprism 18 is the positive direction of the Y axis, and the direction orthogonal to the Z axis and the Y axis is the X axis. The direction is described.

  The camera body 10 includes an image sensor 24 and an optical viewfinder 14. The image sensor 24 is configured by a solid-state image sensor such as a CCD or a CMOS. The optical finder unit 14 provided in the camera body 10 includes a quick return mirror 16, a finder screen 22, a pentaprism 18, and an eyepiece lens 20.

  The quick return mirror 16 is provided inside the camera body 10 so as to be able to rotate between a position indicated by a solid line and a position indicated by a broken line in FIG. When the quick return mirror 16 is at the position indicated by the solid line, the subject light guided from the imaging optical system 26 of the lens barrel 12 into the camera body 10 is reflected by the quick return mirror 16. The subject light reflected by the quick return mirror 16 is guided to the eyes of a photographer looking into the optical viewfinder section 14 by the viewfinder screen 22, the pentaprism 18, the eyepiece lens 20, and the like. Therefore, the photographer looking into the optical viewfinder 14 can observe the subject through the eyepiece 20 or the like.

  On the other hand, at the time of shooting, the quick return mirror 16 moves to a position indicated by a broken line. When the quick return mirror 16 is at the position indicated by the broken line, the subject light guided from the photographing optical system 26 of the lens barrel 12 into the camera body 10 passes through the camera body 10 in the negative Z-axis direction. Proceed toward. The subject light reaches the imaging surface of the image sensor 24 by opening a shutter (not shown) arranged on the positive side of the Z axis of the image sensor 24. Therefore, the image sensor 24 can perform a photographing operation by photoelectrically converting subject light.

  The photographing optical system 26 provided in the lens barrel 12 includes a first lens group 28, a second lens group 30, a third lens group 32, and a diaphragm 34. The lens groups 28 to 32 and the diaphragm 34 are arranged in the order of the first lens group 28, the second lens group 30, the diaphragm 34, and the third lens group 32 from the Z-axis positive direction side to the Z-axis negative direction side. Arranged along the Z-axis.

  The lens groups 28 to 32 of the photographing optical system 26 constitute a zoom lens having a three-group configuration. That is, the first to third lens groups 28 to 32 and the diaphragm 34 can be moved in the Z-axis direction inside the lens barrel 12 by a cam mechanism (not shown). Thereby, the camera shown in FIG. 1 can change the magnification of the photographing optical system 26.

  The first lens group 28 includes a focus adjustment lens 28a. The focus adjustment lens 28a can move relative to the other lenses constituting the photographing optical system 26 in the Z-axis direction. Thereby, the camera shown in FIG. 1 can adjust the focus of the photographing optical system 26.

  The third lens group 32 includes a 3-1 lens group 32a, an image blur correction lens 32b, and a 3-3 lens group 32c. The image blur correction lens 32b is relatively in a direction along the plane (direction along the XY plane) substantially perpendicular to the lens barrel optical axis direction (Z-axis direction) with respect to the other lenses constituting the photographing optical system 26. Can move.

  The image blur correction lens 32b of the third lens group 32 constitutes an image blur correction mechanism 42 together with a drive unit such as a voice coil motor that moves the image blur correction lens 32b in a direction along the XY plane. Further, an angular velocity sensor 38 that detects an angular velocity component of vibration applied to the camera body 10 or the lens barrel 12 is attached to the lens barrel 12 shown in FIG.

  Further, the lens barrel 12 shown in FIG. 1 includes an arithmetic unit that performs signal processing of the angular velocity sensor 38 and communication with the camera body 10, a motor driver of a voice coil motor provided in the image blur correction mechanism 42, and the like. Is mounted on the electric circuit board 40. The arithmetic unit mounted on the electric circuit board 40 can control image blur correction by controlling a voice coil motor of the image blur correction mechanism 42 based on a signal from the angular velocity sensor 38 or the like.

  FIG. 3 is an enlarged cross-sectional view of the image blur correction mechanism 42 provided in the lens barrel 12 shown in FIG. 3A shows a state in which the image blur correction lens 32b is positioned at the control center position, and FIG. 3B shows that the image blur correction lens 32b is positioned at the movable limit position. Indicates the state.

  FIG. 4 is an exploded perspective view of the image blur correction mechanism 42 provided in the lens barrel 12 shown in FIG. The image blur correction mechanism 42 includes a correction lens holding frame 46 that holds the image blur correction lens 32b, first and second voice coil motors 48 and 50, a base member 44, and the like.

  The correction lens holding frame 46 that holds the image blur correction lens 32 b is movably attached to the base member 44 via a tension spring 56 and a steel ball 54. The image blur correction mechanism 42 is provided with three steel balls 54, and each steel ball 54 is accommodated in a recess 58 formed on the surface of the base member 44 facing the correction lens holding frame 46.

  On the other hand, the surface of the correction lens holding frame 46 facing the base member 44 is provided with a steel ball sliding surface 60 that contacts the steel ball 54 and holds the steel ball 54 between the base member 44 and the steel ball 54. Yes. Further, the image blur correction mechanism 42 includes two tension springs 56 that urge the base member 44 and the correction lens holding frame 46 in a direction in which they are pressed against each other.

  One end of the tension spring 56 is engaged with a spring hook 62 provided on the correction lens holding frame 46, and the other end of the tension spring 56 is a spring hook (not fixed) provided on the base member 44. Engaged). The correction lens holding frame 46 is biased toward the base member 44 by a tension spring 56. Therefore, the correction lens holding frame 46 can move in the direction along the XY plane while maintaining the contact between the steel ball sliding surface 60 and the steel ball 54. Since the correction lens holding frame 46 is held with the steel ball 54 interposed, the friction generated when the correction lens holding frame 46 moves in the direction along the XY plane is rolling friction. Therefore, the image blur correction mechanism 42 according to the present embodiment has a small load during driving and is energy saving.

  As shown in FIG. 4, the image blur correction mechanism 42 includes first and second voice coil motors 48 and 50. The second voice coil motor 50 has a coil 50 a attached to the correction lens holding frame 46, a permanent magnet 50 b and a yoke 50 c attached to the base member 44.

  As shown in FIGS. 4 and 3, the yoke 50 c has a substantially U-shaped cross section and is attached to the Y-axis negative direction side of the base member 44. The permanent magnet 50b is fixed to the yoke 50c and is in-plane two-pole magnetized to the N pole and the S pole as shown in FIG. 3A. On the other hand, the coil 50 a is attached to the correction lens holding frame 46. The coil 50 a is disposed at a position close to the yoke 50 c and the permanent magnet 50 b attached to the base member 44. That is, in the state shown in FIG. 3A in which the correction lens holding frame 46 is movably attached to the base member 44, the coil 50a is disposed at a position sandwiched between the permanent magnet 50b and the yoke 50c.

  Therefore, when a current flows through the coil 50a, the coil 50a receives a force in the Y-axis positive direction or the Y-axis negative direction corresponding to the direction of the current flowing through the coil 50a by the magnetic field formed by the permanent magnet 50b and the yoke 50c. . In this way, the second voice coil motor 50 can drive the correction lens holding frame 46 and the image blur correction lens 32b in the Y axis positive direction and the Y axis negative direction.

  Similar to the second voice coil motor 50, the first voice coil motor 48 shown in FIG. 4 has a coil 48a, a permanent magnet 48b, and a yoke 48c. The first voice coil motor 48 is disposed at a position obtained by rotating the second voice coil motor 50 about 90 degrees around the optical axis A of the lens barrel.

  Each member such as the coil 48a, the permanent magnet 48b, and the yoke 48c constituting the first voice coil motor 48 has substantially the same structure as that of the second voice coil motor 50 except for the mounting position with respect to the base member 44 and the correction lens holding frame 46. have. The first voice coil motor 48 can drive the correction lens holding frame 46 and the image blur correction lens 32b in the X axis positive direction and the X axis negative direction.

  The first and second voice coil motors 48 and 50 are controlled by a calculator 75 shown in FIG. The computing unit 75 controls the first and second voice coil motors 48 and 50 via the motor driver 96, and moves the correction lens holding frame 46 and the image blur correction lens 32b attached to the correction lens holding frame 46 to the XY plane. Can be moved in any direction along.

  As shown in FIGS. 3A and 3B, the image blur correction mechanism 42 according to this embodiment includes a correction lens position detection sensor 52 for detecting the position of the image blur correction lens 32 b attached to the correction lens holding frame 46. Is provided. As shown in FIG. 3A, the correction lens position detection sensor 52 arranged on the Y axis positive direction side of the image blur correction mechanism 42 detects the position of the image blur correction lens 32b held by the correction lens holding frame 46. The correction lens position detection sensor 52 detects the position in the direction along the Y axis among the positions of the image blur correction lens 32b.

  The correction lens position detection sensor 52 includes a permanent magnet 52b, a back yoke 52c, and a hall element 52a. The permanent magnet 52b and the back yoke 52c are attached to the correction lens holding frame 46 and move as the image blur correction lens 32b moves.

  The hall element 52 a is attached to the base member 44 and is disposed so as to face the permanent magnet 52 b attached to the correction lens holding frame 46. Here, the Hall element 52a is a sensor that outputs an electrical signal corresponding to a change in magnetic flux density passing through the element 52a. The hall element 52a is electrically connected to the computing unit 75 shown in FIG. 2 via the wiring 52d, and outputs an electrical signal related to the position of the correction lens holding frame 46 to the computing unit 75.

  That is, when the correction lens holding frame 46 shown in FIG. 3A is displaced in the Y-axis direction by the driving force generated by the second voice coil motor 50, the magnetic flux density passing through the Hall element 52a changes. Since the Hall element 52a outputs an electrical signal corresponding to the change in the magnetic flux density to the calculator 75, the shake correction apparatus according to this embodiment determines the position of the image blur correction lens 32b held by the correction lens holding frame 46. Can be recognized.

  Although not shown in FIGS. 3A and 3B, the image blur correction mechanism 42 further includes a correction lens position detection sensor for detecting the position of the image blur correction lens 32b in the direction along the X axis. Yes. The shake correction apparatus according to the present embodiment uses the two correction lens position detection sensors for detecting the positions of the image blur correction lens 32b in the X-axis direction and the Y-axis direction to position the image blur correction lens 32b in the XY plane. Can be recognized.

  FIG. 2 is a block diagram showing an outline of a shake correction apparatus according to an embodiment of the present invention. The shake correction apparatus includes an arithmetic unit (MPU) 75 that controls the voice coil motors 48 and 50 in order to correct image blur. The calculator 75 calculates a control signal for controlling the voice coil motors 48 and 50 based on signals input from the angular velocity sensor 38, the shutter button 82, the correction lens position detection sensor 52, and the like, and outputs the control signal to the motor driver 96.

  In the present embodiment, the computing unit 75 includes an image blur target position calculating unit 78 and a centering target position calculating unit 88. The image blur target position calculation unit 78 calculates an image blur target position signal 80 based on the angular velocity detection signal from the angular velocity sensor 38. The image blur target position signal 80 is a signal obtained by calculating a position at which the image blur correction lens 32b should be moved in order to cancel an image blur caused by vibration applied to the camera and obtain an image in which the image blur is suppressed.

  When vibration is applied to the camera equipped with the shake correction device, an angular velocity detection signal is output from the angular velocity sensor 38 shown in FIG. The angular velocity detection signal output from the angular velocity sensor 38 is amplified to a predetermined signal level by an amplifier 64 including an amplifier circuit and a low-pass filter, and unnecessary high frequency components are removed.

  The adder 68 adds or subtracts the DC signal to the angular velocity detection signal output from the amplifier 64. The DC signal is a signal that has been calculated by the addition output calculation means 70 of the calculator 75 and then converted to an analog signal by the D / A converter 72. The adder 68 adds / subtracts an appropriate DC signal to / from the angular velocity detection signal. As a result, the adder 68 adjusts the angular velocity detection signal so that it has a sufficient vibration amplitude for obtaining a good S / N ratio and does not exceed the dynamic range of the first A / D converter 66. Can do.

  The angular velocity detection signal is converted into a digital signal by the first A / D converter 66 and then input to the calculator 75. The angular velocity detection signal input to the calculator 75 is subtracted by the first subtractor 76 to become an angular velocity signal from which direct current and extremely low frequency have been removed.

  That is, the angular velocity detection signal input to the computing unit 75 is branched into two once, and one of the branched angular velocity detection signals is input to the first low-pass filter (LFP) 74 and includes a low frequency component including direct current. Become. The first subtractor 76 subtracts the signal output from the first low-pass filter 74 from the other branched angular velocity detection signal, thereby obtaining an angular velocity signal that is a fluctuation signal with respect to the camera tilt angle.

  The angular velocity signal output from the first subtractor 76 is input to the image blur target position calculation unit 78. The image blur target position calculation means 78 is based on the focal length of the photographing optical system 26 shown in FIG. 1, the subject distance, the correction lens image plane moving magnification 98, and the like in addition to the angular velocity signal. 80 is calculated.

  When calculating the image blur target position signal 80, the focal length and the like are taken into account even if the same angular velocity signal is obtained, the position where the image blur correction lens 32b should be moved varies depending on the state of the photographing optical system 26. It is to do. The correction lens image plane moving magnification 98 is a ratio between the moving amount of the image blur correcting lens 32b shown in FIG. 1 and the moving amount of the image on the imaging plane of the image pickup device 24 and the finder screen 22.

  The image blur target position signal 80 output from the image blur target position calculating unit 78 is input to the signal switching unit 92. An image blur target position signal 80 and a centering target position signal 90 are input to the signal switching unit 92. The centering target position signal 90 is a signal obtained by calculating a position where the image blur correction lens 32b should be moved so that the image blur correction lens 32b moves toward the control center position 112 shown in FIG. 3 or FIG.

  That is, the image blur target position calculation unit 78 calculates the image blur target position signal 80, while the centering target position calculation unit 88 calculates the centering target position signal 90.

  The shutter button 82 is an operation unit for performing a shooting operation. The shutter button 82 provided in the camera of the present embodiment includes a half-pressed state detection sensor 86 that detects a half-pressed state of the shutter button 82, and a full-pressed state detection sensor 84 that detects a fully-pressed state of the shutter button 82. Is provided. That is, the shutter button 82 is a half-push switch that detects a two-stage depression state.

  The camera can start an AF operation, an image blur correction operation, or the like in response to the timing when the photographer half-presses the shutter button 82 and the half-pressed state detection sensor 86 detects the half-pressed state. Further, the camera can start an exposure operation or the like in response to the timing when the photographer fully presses the shutter button 82 and the fully-pressed state detection sensor 84 detects the fully-pressed state.

  When the photographer half-presses the shutter button 82, a half-press state detection sensor 86 provided in the shutter button 82 outputs a half-press signal. The half-press signal output from the half-press state detection sensor 86 is input to the centering target position calculation means 88. When the half-press signal is input, the centering target position calculation unit 88 starts to calculate the centering target position signal 90 for moving the image blur correction lens 32 b toward the control center position 112. Further, the centering target position calculation unit 88 outputs the centering target position signal 90 calculated by the calculation to the signal switching unit 92.

  The centering target position calculation means 88 uses the position information of the image blur correction lens 32b detected by the correction lens position detection sensor 52, information on the elapsed time from the start of the centering operation, etc. 90 can be calculated. Further, the calculation method of the centering target position signal 90 in the centering target position calculation means 88 may be changed corresponding to the timing when the full press signal is input from the full press state detection sensor 84.

  When the fully-pressed state detection sensor 84 detects the fully-pressed state of the shutter button 82, the fully-pressed state detection sensor 84 outputs a full-press signal not only to the centering target position calculating unit 88 but also to the photographing time detecting unit 85. The shooting time detection unit 85 detects a shooting time, which is a time at which shooting is started, using the time when the full press signal based on the operation of the shutter button 82 is input to the shooting time detection unit 85.

  Here, the photographing time may be, for example, an exposure start time at which exposure is started in the camera shown in FIG. The exposure start time is the time when the subject light starts to reach the image sensor 24 when the quick return mirror 16 shown in FIG. 1 moves (mirror up) to the position indicated by the wavy line and the shutter (not shown) starts to open. . Further, the photographing time may be a predetermined time before and after the exposure start time, or may be a predetermined time after the mirror is raised and before the shutter (not shown) starts to open.

  The shooting time detection unit 85 may detect the shooting time based on, for example, camera body settings or a table prepared in advance in addition to the time when the full-press signal is input to the shooting time detection unit 85. Further, the shooting time detection unit 85 may set a shooting time as a time obtained by adding a predetermined time to the time when the full-press signal is input to the shooting time detection unit 85.

  The shooting time detection unit 85 outputs a signal related to the calculated shooting time to the signal switching unit 92.

  The signal switching unit 92 determines which of the image blur target position signal 80 and the centering target position signal 90 is used to move the image blur correction lens 32b. That is, the signal switching unit 92 outputs either the image blur target position signal 80 or the centering target position signal 90 as the correction lens target position signal 93.

  The signal switching unit 92 can determine the correction lens target position signal 93 by using the position information of the image blur correction lens 32 b and information regarding the shooting time detected by the shooting time detection unit 85. For example, the signal switching unit 92 changes the correction lens target position signal 93 to be output from the centering target position signal 90 to the image blur target position signal 80 when the image blur correction lens 32b moves to the control center position shown in FIG. 3A. Can be switched.

  Further, the signal switching unit 92 switches the correction lens target position signal 93 to be output from the centering target position signal 90 to the image blur target position signal 80 when the shooting time detected by the shooting time detection unit 85 arrives. Also good. The timing of switching the signal output by the signal switching unit 92 may be immediately after the shooting time has elapsed, but is preferably the same as the shooting time or before the shooting time. By ending the centering operation of the image blur correction lens 32b by the photographing time, the shake correction device according to the present embodiment causes the image blur correction lens 32 to perform a movement unrelated to the image blur correction during the exposure. It is prohibited to prevent the photographed image from being shaken.

  The corrected lens target position signal 93 output by the signal switching unit 92 is input to the controller 94. The controller 94 shown in FIG. 2 can be a PID controller, for example, but is not particularly limited as long as good controllability can be obtained.

  The controller 94 outputs a control signal to the motor driver 96 based on the input corrected lens target position signal 93. The motor driver 96 supplies power corresponding to the input control signal to the voice coil motors 48 and 50. The correction lens holding frame 46 provided with the coils 48a and 50a of the voice coil motors 48 and 50 receives the driving force corresponding to the supplied power and moves the image blur correction lens 32b.

  As the image blur correction lens 32b moves, image movement corresponding to an amount obtained by multiplying the movement amount of the image blur correction lens 32b by the correction lens image plane movement magnification 98 occurs on the imaging surface of the image sensor 24. . When the signal switching unit 92 outputs the image blur target position signal 80 as the correction lens target position signal 93, the voice call motors 48 and 50 cancel out image blur caused by vibration applied to the camera. The image blur correction lens 32b is driven. Therefore, the movement of the image due to camera shake is canceled by the movement of the image blur correction lens 32b.

  The image blur correction mechanism 42 according to this embodiment includes a correction lens position detection sensor 52 having a Hall element or the like. The correction lens position detection sensor 52 outputs a signal related to the positions of the image blur correction lens 32 b and the lens holding frame 46. The signal output from the correction lens position detection sensor 52 is converted into a digital signal by the second A / D converter 97 and then input to the calculator 75.

  The input position signal of the image blur correction lens 32 b is subtracted from the correction lens target position signal 93 output from the signal switching unit 92 by the second subtracter 95. Therefore, the correction lens target position signal 93 input to the controller 94 is a control error signal adjusted based on the position detection signal of the image blur correction lens 32b. As described above, the arithmetic unit 75 shown in FIG. 2 performs feedback control using the position detection signal of the image blur correction lens 32b.

  FIG. 6 is a flowchart showing an example of a series of processes performed by the calculator 75 when the calculator 75 shown in FIG. 2 controls the voice coil motors 48 and 50 to drive the image blur correction lens 32b. is there. FIG. 5 is a graph showing the corrected lens target position signal 93 output to the controller 94 or the second subtracter 95 by the signal switching means 92 in the computing unit 75 shown in FIG. In FIG. 5, the time variation of the correction lens target position signal 93 is set such that the position where the image blur correction lens 32 b is located before the start of control from the movable limit position 110 toward the control center position 112 is the vertical axis and time t is the horizontal axis. Represents.

  Hereinafter, an example of the control of the image blur correction lens 32b by the computing unit 75 will be described with reference to FIGS.

  In step S001 in FIG. 6, control of the voice coil motors 48 and 50 by the computing unit 75 is started. For example, when the half-pressed state of the shutter button 82 is detected by the half-pressed state detection sensor 86 shown in FIG. 2, the centering target position calculation unit 88 starts calculating the centering target position signal 90.

  Further, the centering target position calculation unit 88 starts a process of outputting the calculated centering target position signal 90 to the signal switching unit 92. Note that, at the timing when the half-pressed state of the shutter button 82 is detected, the image blur target position calculation unit 78 starts processing to calculate the image blur target position signal 80 and output it to the signal switching unit 92.

  Here, the image blur correction lens 32b of the image blur correction mechanism 42 according to the present embodiment is positioned at the movable limit position 110 shown in FIG. 3B until control of the voice coil motors 48 and 50 by the calculator 75 is started. is doing. That is, the voice coil motors 48 and 50 are in a non-energized state before the control of the voice coil motors 48 and 50 by the computing unit 75 is started. Accordingly, the correction lens holding frame 46 is in a state of being shifted in the direction of gravity and is in contact with the movable limiter 44 a of the base member 44. As shown in FIG. 3B, the movable limiter 44a is provided on the inner peripheral surface side of the ring-shaped base member 44, and restricts the movable range of the image blur correction lens 32b.

  In the present embodiment, the position (FIG. 3B) of the image blur correction lens 32b in a state where the correction lens holding frame 46 is in contact with the movable restriction member 44a of the base member 44 is defined as a movable restriction position 110 (FIG. 5). To explain. On the other hand, as shown in FIG. 3A, the position of the image blur correction lens 32b in a state where the correction lens optical axis B of the image blur correction lens 32b substantially coincides with the lens barrel optical axis A shown in FIG. The description will be made by defining the position 112 (FIG. 5). The camera may include a storage unit (not shown) that stores information such as the movable limit position 110 and the control center position 112.

  As shown in FIG. 3B, when the image blur correction lens 32b is located at the movable limit position 110, the correction lens optical axis B is decentered from the lens barrel optical axis A by the moving region yg. Yes. Therefore, the photographing optical system 26 shown in FIG. 1 is in a state in which the optical performance is inferior to the best optical performance obtained from the photographing optical system 26.

  Therefore, in the camera including the photographing optical system 26, first, the image blur correction lens 32b positioned at the movable limit position 110 is moved to a position close to the control center position 112, and then image blur correction control is started. It is preferable in terms of optical performance. As a result, the calculator 75 can move the image blur correction lens 32b around the control center position 112 where more suitable optical performance is obtained during the image blur correction control.

  In step S001 in FIG. 6, after the control of the voice coil motors 48 and 50 by the calculator 75 is started, the first centering control is performed by the calculator 75 until the full press signal is input. Good (step S002). In the first centering control, the centering target position calculation means 88 shown in FIG. 2 calculates the centering target position signal 90 so that the image blur correction lens 32b is moved at the first speed. The first speed is preferably a speed that is so slow that the photographer cannot sense the movement of the image blur correction lens 32b.

  In the first centering control, the signal switching unit 92 uses the centering target position signal 90 of the image blur target position signal 80 and the centering target position signal 90 input to the signal switching unit 92 as the correction lens target position signal 93. Output as.

  Here, in the example shown in FIG. 5, the full-press signal is input to the calculator 75 at time Tb immediately after the time Ta when the half-press signal is input to the calculator 75 (step S003 in FIG. 6). Such an input occurs, for example, when a photographer who operates the camera pushes the shutter button 82 to the full-press state at once without stopping the push-down of the shutter button 82 half-pressed.

  In the shake correction apparatus according to the present embodiment, when the shutter button 82 is pushed all the way down, the first centering control shown in step S002 can be skipped. That is, when the shutter button 82 is fully pressed at once, the full-press state detection sensor 82 shown in FIG. 2 detects the full-press of the shutter button 82 and outputs a full-press signal to the centering target position calculation means 88 of the calculator 75. To do. When the full press signal is input immediately after the half press signal is input, the computing unit 75 performs the second centering control without performing the first centering control, as shown in FIG. 5 (step S004).

  In the second centering control performed in step S004 of FIG. 6, the centering target position calculation unit 88 shown in FIG. 2 performs centering so as to move the image blur correction lens 32b at the second speed v2, as shown in FIG. A target position signal 90 is calculated. Here, it is preferable that the second speed v2 of the second centering control is faster than the first speed in the first centering control.

  In the second centering control, as shown in FIG. 5, the image blur correction lens 32b may be controlled to move at substantially constant speed, or the image blur correction lens 32b is controlled to move while accelerating / decelerating. You may do it. Alternatively, the second speed v2 is the fastest speed among the speeds at which the image blur correction lens 32b is controlled by a signal from the image blur target position calculating unit 78 or the centering target position calculating unit 88 shown in FIG. Also good.

  Also in the second centering control, the signal switching unit 92 shown in FIG. 2 outputs the centering target position signal 90 as the corrected lens target position signal 93, similarly to the first centering control. As shown in FIG. 5, the signal switching unit 92 starts outputting the correction lens target position signal 93 in the second centering control from the time Tc slightly delayed from the time Tb when the full press signal of the shutter button 82 is input. To do.

  Before the control by the calculator 75 is started, the image blur correction lens 32b positioned at the movable limit position 110 is controlled to move toward the control center position 112 at the second speed v2 by the second centering control. The

  While the second centering control is being performed, the shooting time detection unit 85 illustrated in FIG. 2 detects the shooting time Te based on the full press signal output from the full press state detection sensor 84. The photographing time detection unit 85 outputs the detected photographing time Te to the signal switching unit 92 as soon as the detection of the photographing time Te is completed.

  Next, when a time Td that is a predetermined time before the photographing time Te comes, the switching unit 92 prohibits centering control by performing the processing shown in steps S005 to S007 in FIG. In this case, the prohibition of the centering control means that the center rig control for moving the image blur correction lens 32b toward the control center position 112 is stopped even before the image blur correction lens 32b reaches the control center position 112. means.

  That is, the computing unit 75 according to the present embodiment controls the voice coil motors 48 and 50 to prohibit the centering control when a time Td that is a predetermined time before the photographing time Te comes. Since the shake correction apparatus according to the present embodiment prohibits centering control corresponding to the shooting time Te even before the image blur correction lens 32b reaches the control center position 112, the shake correction device surely precedes the shooting time Te. Image blur correction can be started.

  When the time Td arrives, the computing unit 75 shown in FIG. 2 determines whether the image blur correction by the shake correction device is effective or has been stopped (step S005 shown in FIG. 6). Here, the lens barrel 12 or the camera body 10 shown in FIG. 1 is provided with an image blur correction mode changeover switch (not shown). The photographer can set whether to enable the image blur correction control by the image blur correction mechanism 42 or the like or to stop the image blur correction by operating the image blur correction mode changeover switch.

  When it is determined in step S005 shown in FIG. 6 that the image blur correction has been stopped, the calculator 75 holds the image blur correction lens 32b at the place 114 where the image blur correction lens 32b is located at time Td. The voice coil motors 48 and 50 are controlled (step S007 in FIG. 7). On the other hand, when the image blur correction control by the image blur correction mechanism 42 is effective, the computing unit 75 starts the image blur correction control (step S006). FIG. 5 shows a corrected lens target position signal 93 when the process proceeds to step S006 in the flowchart shown in FIG.

  In the image blur correction control in step 006, the signal switching unit 92 shown in FIG. 2 uses the image blur target position signal 80 input from the image blur target position calculation unit 78 instead of the centering target position signal 90 as a correction lens target. The position signal 93 is output to the second subtracter 95 and the controller 94. That is, the centering control is prohibited by switching the output signal by the signal switching means 92.

  As shown in FIG. 5, the image blur correction lens 32b moves to cancel the image blur caused by the vibration applied to the camera by the image blur correction control started from time Td.

  The shooting time Te shown in FIG. 5 is the exposure start time when the exposure operation starts in the camera shown in FIG. 1, and the time Tf is the time when the exposure operation ends. As shown in FIG. 5, the computing unit 75 according to the present embodiment moves the image blur correction lens 32b so as to be close to the control center position 112 until time Td, and then switches control at time Td, Image blur correction control is started before Te.

  If it is determined in step S005 shown in FIG. 7 that the image blur correction has been stopped, the calculator 75 causes the voice so that the image blur correction lens 32b is held at the location 114 where the image blur correction lens 32b is located at time Td. The coil motors 48 and 50 are controlled (step S007). That is, the centering control is prohibited by changing the correction lens target signal 93 output by the signal switching unit 92.

  In this case, the exposure operation is performed with the image blur correction lens 32b held at the position 114. In the present embodiment, the control signal for controlling the image blur correction lens 32b to be held at the position 114 may be calculated by the centering target position calculating unit 88 shown in FIG. 2, or calculated by the image blur target position calculating unit. May be.

  If the image blur correction lens 32b does not reach the control center position 112 by the photographing time Te even if the switching means 92 performs the process for inhibiting the centering control (steps S005 to S007) and the second centering process. You may set so that it may perform only when it judges. When the image blur correction lens 32b can reach the control center position 112 by the second centering control by the shooting time Te, the image blur correction control is started by the shooting time Te even if the centering control is not prohibited. Because you can.

  After the exposure operation is completed through step S006 or step S007, when the half-pressed state of the shutter button 82 is not detected by the half-pressed state detection sensor 86, the computing unit 75 ends the control of the voice coil motors 48 and 50. (Step S008 in FIG. 7). When the computing unit 75 finishes controlling the voice coil motors 48, 50, the voice coil motors 48, 50 are in a non-energized state. When the voice coil motors 48 and 50 are in a non-energized state, the correction lens holding frame 46 is shifted in the gravitational direction as shown in FIG. 3B and moved to a position where it comes into contact with the movable restricting portion 44a of the base member 44.

  As shown in FIG. 5, the calculator 75 operates so that the image blur correction lens 32 moves to the movable limit position 110 while gradually decelerating after a time Tg when the half-pressed state of the shutter button 82 is not detected. The coil motors 48 and 50 may be controlled. By moving the image blur correction lens 32b toward the movable limit position 110 while gradually decelerating, it becomes difficult for the photographer to detect the movement of the image accompanying the movement of the lens, and the photographer feels uncomfortable from the viewfinder image. The phenomenon is suppressed.

  As described above, the shake correction apparatus according to the present embodiment prohibits centering control corresponding to the shooting time Te even before the image blur correction lens 32b reaches the control center position 112. The blur correction control can be started before Te. The time Td during which the centering control is prohibited can be a predetermined time before the shooting time Te, and is preferably several ms to several tens of ms before the shooting time Te. This is to stabilize the movement of the image blur correction lens 32 by the photographing time Te.

  Therefore, the shake correction apparatus according to the present embodiment can prevent the image blur correction lens 32b from performing a movement unrelated to the shake correction during the exposure operation. In addition, the shake correction apparatus according to the present embodiment starts image blur correction control before starting exposure or starts control to hold the image blur correction lens 32b, so that the captured image is in a shake state. Can be prevented.

  Furthermore, in the shake correction apparatus according to the present embodiment, the time from when the shutter button 82 is pressed until the start of exposure does not depend on the time required to move the shake correction lens 32b to the control center position 112. The photographing operation can be performed at the timing. In other words, depending on the position of the shake correction lens 32b when the shutter button 82 is fully pressed, it is possible to prevent the time from the full press to the start of exposure from being prolonged, so that exposure is performed at the timing intended by the photographer. Therefore, it is possible to prevent missing a photo opportunity.

  The camera having the shake correction apparatus according to the present embodiment starts the image blur correction after moving the image blur correction lens 32b toward the control center position 112 after the full-press signal is input, and then performs shooting. Start. When the image blur correction control is stopped, after the full press signal is input, the image blur correction lens 32b is moved toward the control center position 112, and then the image blur correction lens is held. Start shooting. Therefore, in the camera having the shake correction apparatus according to the present embodiment, the image blur correction lens 32b can be arranged at a position where the optical performance is good, and a shooting operation can be performed.

  Further, the computing unit 75 included in the shake correction apparatus according to the present embodiment has a voice so that the speed of the image blur correction lens 32b becomes higher after the shutter button 82 is fully pressed than before the shutter button 82 is fully pressed. The coil motors 48 and 50 may be controlled. Before the shutter button 82 is fully pressed, the image blur correction lens 32b can be moved at a low speed to make it difficult for the photographer to detect the movement of the image accompanying the movement of the lens. After the shutter button 82 is fully pressed, the image blur correction lens 32b is moved at a high speed and the image blur correction lens 32b is arranged so as to be close to the control center position 112 where the optical performance is good. , Can start shooting.

Further, in the shake device according to the present embodiment, it is not necessary to provide a lock mechanism that locks the image blur correction lens 32b near the control center position 112. That is, in the shake correction apparatus according to the present embodiment, even when the image blur correction lens 32b is positioned near the movable limit position 110 before the shutter button 82 is operated, the image blur correction is quickly performed after the shutter button 82 is operated. The lens 32b can be arranged at a position suitable for optical performance, and photographing can be started at the timing as intended by the photographer. Therefore, in the shake device according to the present embodiment, the structure of the image blur correction lens 32b can be simplified by omitting the lock mechanism.
Other embodiments

  In the above-described embodiment, the optical component that is driven to correct the image blur is the image blur correction lens 32b. The optical component that is controlled by the computing unit 75 and is driven to correct the image blur. However, the imaging device 24 may be used. Even in the shake correction device that moves the image sensor 24, the image sensor 24 is moved in the same manner as the image blur correction lens 32b in the above-described embodiment, thereby suppressing image blur and maintaining good optical performance. A photographing operation can be performed. In the above-described embodiment, the centering control is prohibited before the photographing time Te, but the present invention is not limited to this. For example, the time when the centering control is prohibited may be the same as the shooting time Te or slightly later than the shooting time Te.

  The control center position 112 stored in the storage unit is not limited to the position where the correction lens optical axis B substantially coincides with the lens barrel optical axis A, and other positions where the optical characteristics of the imaging optical system 26 are good, It is also possible to use a position farthest from the limiting member or a reference position for calculation. The photographing operation unit may be another operation unit that starts a photographing operation, and the preparation operation unit may be a power switch of a camera or the like, for example.

FIG. 1 is a cross-sectional view showing a camera in which a shake correction apparatus according to an embodiment of the present invention is built. FIG. 2 is a block diagram showing an outline of control of the shake correction apparatus in the camera shown in FIG. 3 is an enlarged cross-sectional view of a shake correction mechanism provided in the lens barrel shown in FIG. 4 is an exploded perspective view of a shake correction mechanism provided in the lens barrel shown in FIG. FIG. 5 is a graph showing an example of a correction lens target position signal output from the arithmetic unit of the shake correction apparatus according to the embodiment of the present invention. FIG. 6 is a flowchart showing a series of processes performed when controlling the voice coil motor in the arithmetic unit of the shake correction apparatus according to the embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Camera body part 12 ... Lens barrel 24 ... Image pick-up element 26 ... Shooting optical system 32b ... Image blur correction lens 42 ... Image blur correction mechanism 44 ... Base member 46 ... Correction lens holding frame 48, 50 ... Voice coil motor 52 ... Correction lens position detection sensor 75 ... calculator 78 ... image blur target position calculation means 80 ... image blur target position signal 82 ... shutter button 84 ... full-pressed state detection sensor 85 ... imaging time detector 86 ... half-pressed state detection sensor 88 ... Centering target position calculation means 90 ... Centering target position signal 92 ... Signal switching means 110 ... Movable limit position 112 ... Control center position A ... Lens barrel optical axis B ... Correction lens optical axis Te ... Shooting time

Claims (10)

An optical component movably provided;
A drive unit for driving the optical component to correct image blur;
The drive unit is caused to perform the first control so that the optical component is driven toward the control center side of the optical component, and the first control is prohibited in accordance with a shooting time at which shooting is started. A shake correction apparatus comprising: a control unit that controls the drive unit. The shake correction apparatus according to claim 1,
When the first control is prohibited, the control unit controls the optical component so as to correct an image blur. The shake correction apparatus according to claim 1 or 2,
A shake correction apparatus comprising: a detection unit that detects the shooting time based on an operation of an operation unit for performing a shooting operation. The shake correction apparatus according to any one of claims 1 to 3, wherein
The shake correction apparatus, wherein the control unit prohibits the first control a predetermined time before the photographing time. The shake correction apparatus according to any one of claims 1 to 4, wherein
When the control unit determines that the optical component does not reach the control center by the photographing time, the control unit is configured to prohibit the driving of the optical component toward the control center before the photographing time. A shake correction apparatus characterized by controlling. The shake correction device according to any one of claims 3 to 5, wherein
A storage unit that stores time from the operation of the operation unit to the shooting time;
The shake correction apparatus, wherein the detection unit detects the photographing time using information in the storage unit. The shake correction apparatus according to any one of claims 3 to 6, wherein
The control unit controls the drive unit such that the speed of the optical component after the operation of the operation unit is larger than the speed of the optical component before the operation of the operation unit. A shake correction device characterized by the above. The shake correction apparatus according to any one of claims 1 to 7,
An imaging device having an operation unit for performing an imaging operation. An imaging apparatus according to claim 8, wherein
A blur correction stop operation unit for stopping image blur correction by the drive unit;
When the image blur correction is stopped by the blur correction stop operation unit, the control unit holds the optical component in the vicinity of the position of the optical component when the first control is prohibited. An imaging device characterized by controlling. The imaging device according to claim 8 or 9, wherein
A storage unit that stores information on the position of the optical component that provides good optical characteristics;
The said control part performs control by setting the position of the said optical component as which the said optical characteristic memorize | stored in the said memory | storage part becomes favorable as said control center.

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