JP3867359B2 - Blur correction device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a shake correction apparatus that corrects a shake in an optical apparatus such as a camera, a video, and binoculars.
[0002]
[Prior art]
Conventionally, a camera shake is detected by an angular velocity sensor, and a blur correction optical system that constitutes part or all of the photographing optical system is driven in a direction to cancel the blur, thereby correcting the blur on the film surface. Correction devices are known. The blur generated in the camera has six degrees of freedom, ie, a three-degree-of-freedom rotational movement consisting of pitching, yawing and rolling movements, and a three-degree-of-freedom translational movement consisting of movements in the x-axis, y-axis and z-axis directions. Yes. A conventional shake correction apparatus normally corrects a shake with respect to a two-degree-of-freedom motion including a pitching and yawing motion.
[0003]
[Problems to be solved by the invention]
There are roughly two types of camera shake. One is a blur that is not intended by the photographer, and is usually a blur called a camera shake. This camera shake needs to be corrected to affect the shooting. The other is a blur intended by the photographer, for example, a panning operation or composition change. When the photographer intends to perform panning shooting, when the camera starts to follow the subject and starts to pan, the conventional shake correction device cannot distinguish between panning and camera shake. will have to go. For this reason, a phenomenon occurs in which the image in the finder does not move even though the camera starts to swing sideways.
[0004]
Similarly, when a photographer starts a composition change, the conventional shake correction apparatus cannot distinguish between the composition change operation and the camera shake, and therefore corrects the composition change operation and immediately after the composition change operation starts. The correction optical system is driven. As a result, the image on the viewfinder does not move even though the photographer moves the camera to change the composition. When the blur correction optical system is driven to the movable range limit, the blur correction operation becomes impossible. Therefore, the image on the finder starts to move only when the blur correction optical system is driven to the movable range limit. The above phenomenon has a problem that the wider the blur correction range, the easier it is for the photographer to feel, and it becomes difficult for the photographer to take the intended composition on the viewfinder. On the other hand, if the correction range is narrowed to prevent this phenomenon, there is a problem that it is difficult to confirm the effect of blur correction on the viewfinder.
[0005]
An object of the present invention is to provide a shake correction apparatus that can perform framing without giving a sense of incongruity to a photographer.
[0006]
[Means for Solving the Problems]
  The present invention solves the above problems by the following means. In addition, in order to make an understanding easy, although the code | symbol corresponding to embodiment of this invention is attached | subjected and demonstrated, it is not limited to this.
  That is, the invention of claim 1
A blur detection unit (2x, 2y) that detects a blur and outputs a blur detection signal (ω), a blur correction optical system (10) that corrects the blur, and a drive unit (3x, 2) that drives the blur correction optical system 3y) and the movable range of the blur correction optical systemSet to the first rangeRange of movementSettingPart (55)And saidBased on shake detection signalWhen it is determined that the blur is larger than a predetermined range,The movable rangeIn a second range wider than the first range.Change (S160, S230)Movable range changing part (54) andHavingTheThis is a characteristic blur correction device.
[0007]
  The invention of claim 2 includes a shake detection unit (2x, 2y) that detects a shake and outputs a shake detection signal (ω), a shake correction optical system (10) that corrects the shake, and the shake correction optical system. A driving unit (3x, 3y) for driving, a target driving position calculating unit (53) for calculating a target driving position of the blur correction optical system based on the blur detection signal and outputting a target position signal (X); , The movable range of the blur correction optical systemSet to the first rangeRange of movementSettingPart (55)And saidBased on the target position signalWhen it is determined that the blur is larger than a predetermined range,The movable rangeIn a second range wider than the first range.Change (S160, S230)A movable range changing section (54);TheTo have preparedThis is a characteristic blur correction device.
[0009]
  Claim3The invention of claim1 or claim 2The shake correction apparatus according to claim 1, further comprising: a control unit (58) that drives and controls the drive unit based on the shake detection signal or the target position signal, wherein the control unit has a movable range.The firstWhen it is within the range, the blur correction device is characterized in that the drive unit drives the blur correction optical system at or near the center (I) of the movable range.
[0010]
  Claim4The invention of claim1Or claim2In the shake correction apparatus described inA comparison unit (54) for comparing the blur detection signal or the target position signal with a comparison value, wherein the comparison value is a maximum set value (X _max ) And minimum set value (X _min )The movable rangeChangeDepartmentBy the comparison unitThe blur detection signal or the target position signal exceeds the maximum set value within a set time and falls below the minimum set value.It was judgedSometimes the movable range isSet to the second range(S160, S230).
[0011]
  Claim5The invention of claim4In the shake correction apparatus according to the above, the movable range.ChangePart of the movable rangeSaid second rangeWhen the blur detection signal or the target position signal does not exceed the maximum set value within a set time and does not fall below the minimum set value after changing toSaid first rangeReturn toMakeThis is a shake correction apparatus characterized by the above.
[0012]
  Claim6The invention of claim1Claims from5The blur correction device according to any one of the preceding claims, wherein the movable range isChangeThe shooting unit moves the movable range during the shooting operation (S290).Change to the second rangeThis is a shake correction apparatus characterized by the above.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
Hereinafter, a first embodiment of the present invention will be described in more detail with reference to the drawings.
First, the blur correction apparatus according to the first embodiment of the present invention will be described using a single-lens reflex camera equipped with the blur correction apparatus as an example.
FIG. 1 is a perspective view showing a state in which a shake correction apparatus according to a first embodiment of the present invention is mounted on a single-lens reflex camera. FIG. 2 is a block diagram of the shake correction apparatus according to the first embodiment of the present invention.
[0015]
The interchangeable lens 8 is detachably attached to the camera body 1, and the interchangeable lens 8 includes angular velocity sensors 2x and 2y, a shake correction lens 10, VCMs 3x and 3y, position detection units 4x and 4y, and the like. Yes.
[0016]
The angular velocity sensors 2x and 2y monitor blurring motion that occurs in the camera body 1 and the interchangeable lens 8. As the angular velocity sensors 2x and 2y, piezoelectric vibration type angular velocity sensors that detect Coriolis force generated by rotation are usually used. As shown in FIG. 1, the angular velocity sensor 2x is an angular velocity meter that detects blur in the pitching direction as angular velocity information when the camera body 1 and the interchangeable lens 8 cause pitching. The angular velocity sensor 2y is an angular velocity meter that detects a blur in the yawing direction as angular velocity information when the camera body 1 and the interchangeable lens 8 cause yawing. The angular velocity sensors 2x and 2y have the same structure, and the angular velocity sensor 2y is not shown in FIG. The angular velocity sensor 2x outputs detected angular velocity information (angular velocity signal) to the filter 51x that cuts high-frequency noise components and DC components.
[0017]
The blur correction CPUs 5x and 5y, for example, calculate target drive position information corresponding to the blur correction amount or drive a voice coil motor (hereinafter referred to as VCM) 3x in order to drive the blur correction lens 10 in a direction to cancel the blur amount. , 3y is instructed to the PWM driver 53x, 53y to stop or drive. The blur correction CPUs 5x and 5y are target drive position information for driving the blur correction lens 10 to the target position based on the focal length information and lens data transmitted from the lens CPU 7, the subject distance information transmitted from the main CPU 6, and the angular velocity signal. Is calculated. Further, the blur correction CPUs 5x and 5y drive control the VCMs 3x and 3y based on the position detection information output from the position detection units 4x and 4y and the calculated target drive position information. To the shake correction CPUs 5x and 5y, a shake correction start switch 14 for starting a shake correction device by an ON operation is connected. The blur correction CPUs 5x and 5y take in the angular velocity signals that have passed through the filters 51x and 51y and are digitized (quantized) via the A / D converters 52x and 52y, respectively. The blur correction CPUs 5x and 5y output the calculated target drive position information to the VCMs 3x and 3y via the PWM drivers 53x and 53y, respectively. The shake correction CPU 5y is not shown in FIG.
[0018]
The lens CPU 7 is a central processing unit that outputs, for example, focal length information and lens data read from the EEPROM to the blur correction CPUs 5x and 5y. The lens CPU 7 is connected to an EEPROM 71 in which lens data, which is various kinds of unique information regarding the interchangeable lens 8, is written. Further, the focal length information related to the focal length is input to the lens CPU 7.
[0019]
The blur correction lens 10 is a lens that constitutes a part or all of the photographing optical system and corrects blur by being driven in a direction perpendicular to the optical axis I. The outer periphery of the vibration reduction lens 10 is held by the inner periphery of the lens frame 11.
[0020]
The VCMs 3x and 3y drive the shake correction lens 10 in a plane perpendicular to the optical axis I (in the xy plane in the figure). The VCMs 3x and 3y have the same structure, and the VCM 3y is not shown in FIG. 2 and will be described below centering on the VCM 3x. The VCM 3x includes a yoke 34x attached to the attachment member 30x, a magnet 32x that forms a magnetic field between the yoke 34x, and a coil 31x that is disposed between the yoke 34x and the magnet 32x and attached to the lens frame 11. And a yoke 33x that is attached to the surface of the attachment member 35x on the side of the lens frame 11 and fixes the magnet 32x, and a wire (not shown) that supports the lens frame 11 movably within the xy plane. When the coil 31x is energized, the VCM 3x generates a force in the direction of the arrow in the drawing to drive the blur correction lens 10. The VCM 3y generates a driving force in the yaw direction (x-axis direction).
[0021]
The position detectors 4x and 4y monitor the position of the blur correction lens 10 in a plane perpendicular to the optical axis I. The position detection units 4x and 4y are provided at positions facing the VCMs 3x and 3y. The position detectors 4x and 4y have the same structure, and the position detector 4y is not shown in FIG. The position detection unit 4x is disposed between the IRED 41x attached to the attachment member 40x, the one-dimensional PSD 43x attached to the attachment member 44x, and the IRED 41x and PSD 43x, and attached to the outer periphery of the lens frame 11. And a slit member 42x for limiting the light flux from the IRED 41x. The position detection unit 4x is configured to detect infrared light that is projected from the IRED 41x and incident on the PSD 43x through the slit member 42x. The position detector 4x detects the position of the light that moves on the PSD 43x as the slit member 42x moves, and detects the actual driving position of the blur correction lens 10. The position detection unit 4x outputs a position detection signal (position detection information) output from the PSD 43x to the blur correction CPU 5x via the A / D converter 54x. The position detection unit 4y detects the position of the shake correction lens 20 in the yaw direction (x-axis direction).
[0022]
For example, based on the ON operation of the release switch 60, the main CPU 6 instructs the blur correction CPUs 5x and 5y to drive the blur correction lens 10, drives the film winding mechanism unit 12 and the shutter mechanism unit 13, and controls the blur. This is a central processing unit that transmits subject distance information to the correction CPUs 5x and 5y and turns on the first timer 62 and the second timer 63. The main CPU 6 is connected to a release switch 60, a film winding mechanism unit 12 that winds up a film, a shutter mechanism unit 13 that opens and closes a shutter, a first timer 62, and a second timer 63. In addition, subject distance information related to the distance to the subject is input to the main CPU 6. The main CPU 6 can communicate with the blur correction CPUs 5 x and 5 y via the lens contact 9.
[0023]
The release switch 60 is a switch that starts a series of shooting preparation operations by a half-press operation and starts shooting operations such as driving of the film winding mechanism unit 12 and the shutter mechanism unit 13 by a full-press operation.
[0024]
Next, a calculation method from the angular velocity information to the target drive position information of the shake correction apparatus according to the first embodiment of the present invention will be described.
FIG. 3 is a block diagram of a calculation unit of the shake correction CPU in the shake correction apparatus according to the first embodiment of the present invention.
Hereinafter, a case where the blur correction lens 10 is driven in the x-axis direction from the angular velocity information output from the angular velocity sensor 2x will be described as an example.
[0025]
The angular velocity = 0 algorithm 50 calculates the center value (value of ω = 0 (zero)) from the output signal (angular velocity information) ω of the angular velocity sensor 2x. When the output signal ω of the angular velocity sensor 2x fluctuates while the camera body 1 and the interchangeable lens 8 are stationary, the blur correction CPU 5x erroneously recognizes that the camera body 1 and the interchangeable lens 8 are blurring, and the blur correction lens 10 Try to correct the blur. For this purpose, it is necessary to calculate the center value of the output signal ω of the angular velocity sensor 2 x by the angular velocity = 0 algorithm 50. The angular velocity = 0 algorithm 50 subtracts the calculated center value from the output signal ω of the angular velocity sensor 2x to calculate angular velocity information that needs to be corrected. Angular Velocity Information Angular Velocity = 0 The algorithm 50 calculates a center value by a moving average method, a digital filter, or the like.
[0026]
The integrator 51 is for integrating the angular velocity information that needs to be corrected into the angle information θ.
[0027]
The overflow prevention table 52 prevents an overflow of integration when the angular velocity sensor 2x detects a blur of the camera body 1 and the interchangeable lens 8 as an angular velocity component in the same direction for a long time.
FIG. 4 is a diagram showing an overflow prevention table in the shake correction apparatus according to the first embodiment of the present invention.
As shown in FIG. 4, the overflow prevention table 52 generates an output signal according to the magnitude of the angle information θ after integration. When the angle information exceeds −θ1 and falls below θ1, the overflow prevention table 52 is zero without generating an output signal. On the other hand, the overflow prevention table 52 outputs a negative value signal when the angle information is −θ2 or more and −θ1 or less, and outputs a positive value signal when the angle information is θ1 or more and θ2 or less. The overflow prevention table 52 prevents the overflow by subtracting the generated output signal from the angular velocity information. The overflow prevention table 52 is not used during the exposure operation. When the overflow prevention table 52 is used in a situation where the angle information θ is about to be saturated, the angular velocity information varies depending on the output signal. As a result, the blur correction CPU 5x erroneously recognizes this fluctuation value as a blur of the camera body 1 and the interchangeable lens 8, and the blur correction lens 10 corrects it.
[0028]
The ideal target position converter 53 converts the angle information θ after integration into ideal target drive position information (hereinafter referred to as target drive position information) X of the shake correction lens 10. As illustrated in FIG. 3, the ideal target position conversion unit 53 calculates target drive position information X based on the focal length information f, the shake correction coefficient α, and the subject distance information D. Here, the shake correction coefficient α is a ratio of the correction amount on the film surface to the drive amount of the shake correction lens 10. The larger the value of the blur correction coefficient α, the smaller the drive amount of the blur correction lens 10 is for the same blur. The blur correction coefficient α is expressed as a function of the focal length f. The target drive position information X is expressed by the following expression when the subject is far away.
X = f × θ × β / α (f)
Here, θ is the blur angle, and β is a constant. When the subject is close, the blur correction amount is changed using the subject distance information D. The ideal target position conversion unit 53 outputs the calculated target drive position information X to the comparator 54.
[0029]
The comparator 54 indicates that the target drive position information X is the comparison value X_max, X_minIt counts the number of times exceeding. The comparator 54 compares the target drive position information X with a preset comparison value (set value) X._max, X_minAnd the target drive position information X is output as it is. Target drive position information X ′ obtained by subtracting the output signal of the position bias table 56 from the target drive position information X is input to the movable range limiter 55.
[0030]
The movable range limiter 55 restricts the drive range (movable range) of the blur correction lens 10 in terms of software. The movable range limiter 55 is provided inside a mechanical limit that mechanically restricts the driving range of the shake correction lens 10. Based on the comparison result of the comparator 54, the movable range limiter 55 widens the soft limit value from ± L1 to ± L2, and moves the movable range of the shake correction lens 10 from a narrow movable range (−L1 to L1) to a wide movable range (−L1 to L1). -L2 to L2). In the embodiment of the present invention, the soft limit value ± L2 is preferably set to about 1.5 to 2 times the soft limit value ± L1. The movable range limiter 55 outputs target drive position information X ′ to the PID control unit 58.
[0031]
FIG. 5 is a block diagram of a control unit of the shake correction CPU in the shake correction apparatus according to the first embodiment of the present invention.
The PID control unit 58 controls the VCM 3x so as to drive the blur correction lens 10 based on the target drive position information X ′. The PID control unit 58 controls the VCM 3x based on information obtained by subtracting the position detection information x related to the blur correction lens 10 output from the PSD 43x from the target drive position information X ′. The PID control unit 58 outputs a signal obtained by subtracting the output signal of the second-order differentiation unit 59 from the output signal to the PWM driver 53x. The PSD 43 x monitors the position of the shake correction lens 10 that is driven through the PID control unit 58 and outputs position detection information x to the position bias table 56 and the speed bias table 57.
[0032]
The second-order differentiation unit 59 performs second-order differentiation on the position detection information x output from the PSD 43 x to calculate the acceleration of the blur correction lens 10. The second-order differential unit 59 subtracts the output signal (second-order differential value) from the output signal of the PID control unit 58 so that the motion compensation lens 10 does not move excessively.
[0033]
The position bias table 56 corrects the drive position of the shake correction lens 10 in order to keep the drive amount of the shake correction lens 10 within the movable range and to minimize the speed fluctuation of the shake correction lens 10. .
FIG. 6 is a diagram showing a position bias table in the shake correction apparatus according to the first embodiment of the present invention.
As shown in FIG. 6, the position bias table 56 is zero without generating an output signal when the position detection information x of the blur correction lens 10 exceeds −x1 and falls below x1. On the other hand, the position bias table 56 generates an output signal as shown in FIG. 6 when the position detection information x is −L or more and −x1 or less or x1 or more and L or less. As shown in FIG. 3, the output signal of the position bias table 56 is subtracted from the target drive position information X output from the comparator 54. As a result, when excessive target drive position information X is to be input to the movable range limiter 55, the target drive position information X is distorted by the position bias table 56, and the blur correction lens 10 is within the movable range (−L1 to L1). ) To drive. Further, when an excessive shake that collides with the movable range limit (−L, L) is input to the angular velocity sensor 5 x, the position bias table 56 minimizes the speed fluctuation of the shake correction lens 10.
[0034]
The speed bias table 57 is a blur correction lens so that when the blur correction lens 10 is driven around a position deviated from the center of the movable range, the blur correction lens 10 is driven at or near the center of the movable range. 10 drive speed is corrected.
FIG. 7 is a diagram showing a speed bias table in the shake correction apparatus according to the first embodiment of the present invention.
The speed bias table 57 does not generate an output signal when the position detection information x of the blur correction lens 10 exceeds −x1 and falls below x1, but when it is −L or more and −x1 or less or x1 or more and L or less, FIG. As shown, an output signal is generated. As shown in FIG. 3, the output signal of the velocity bias table 57 is subtracted from the angular velocity information that needs to be corrected to correct the angular velocity information.
[0035]
Next, the operation of the shake correction apparatus according to the first embodiment of the present invention will be described.
FIG. 8 is a flowchart for explaining the operation of the shake correction apparatus according to the first embodiment of the present invention. FIG. 9 is a diagram for explaining the operation of the shake correction apparatus according to the first embodiment of the present invention.
Hereinafter, the operation of the comparator 54 and the movable range limiter 55 will be mainly described.
In step (hereinafter referred to as S) 100, the soft limit is set to ± L1. When the release switch 60 is pressed halfway, the main CPU 6 outputs a shake correction start signal to the shake correction CPUs 5x and 5y, and a power supply unit (not shown) supplies power to the angular velocity sensors 2x and 2y. Further, in synchronization with the half-pressing operation of the release switch 60, the main CPU 6 turns on a half-pressing timer (not shown). Immediately after the power is turned on, the soft limit value of the movable range limiter 55 is set to ± L1, and the movable range of the shake correction lens 10 is restricted to a narrow movable range (−L1 to L1).
[0036]
In S110, blur correction is started. The blur correction CPUs 5x and 5y start a series of blur correction operations based on the blur correction start signal from the lens CPU 6. The blur correction CPUs 5x and 5y calculate the target drive position information X by the ideal target position conversion unit 53 based on the angular speed information ω output from the angular speed sensors 2x and 2y. As shown in FIG. 9, the target drive position information X is the time T₀~ T₁At the first point of time, the comparison value X is small and has a minimum set value._minComparison value X that is larger than the maximum set value_maxSmaller than. In this state, the soft limit value is set to ± L1, and the movable range of the blur correction lens 10 is restricted to a narrow movable range (−L1 to L1). However, even if the blur correction lens 10 is driven at or near the optical axis I that is the center of the movable range, the blur correction effect can be sufficiently obtained because the blur is small.
[0037]
In S120, the first timer 62 is turned on. In synchronization with the half-pressing operation of the release switch 60, the main CPU 6 instructs the first timer 62 to turn on.
[0038]
In S130, the comparator 54 determines that the target drive position information X is the comparison value X._maxIt is judged whether it is larger than. Target drive position information X is comparison value X_maxIf it is larger, the process proceeds to S140, where the target drive position information X is the comparison value X._maxIf it is smaller, the process proceeds to S200.
[0039]
In S140, the second timer 63 is turned on. As shown in FIG. 9, the blur width becomes wider and the target drive position information X becomes the comparison value X._maxThe second timer 63 is turned on by the main CPU 6 at the same time or substantially at the same time.
[0040]
In S150, the comparator 54 determines that the target drive position information X is the comparison value X._maxOr less. As shown in FIG. 9, the target drive position information X is compared with the comparison value X during the ON operation of the second timer 63 (before timeout)._minWhen the value is less than, the comparator 54 determines that a large blur is input and the blur width is widened, and the process proceeds to S160. On the other hand, the target drive position information X is the comparison value X_minIf greater than, the process proceeds to S170.
[0041]
In S160, the soft limit is set to ± L2. As shown in FIG. 9, the target drive position information X exceeds the soft limit value ± L1 when the blur width increases. As a result, if the drive range of the shake correction lens 10 is set to a narrow movable range (-L1 to L1), the effect of shake correction cannot be obtained. When the comparator 54 determines that a large shake has been input during the ON operation of the second timer 63, the time T₁The soft limit value of the movable range limiter 55 is changed from ± L1 to ± L2. For this reason, the movable range of the vibration reduction lens 10 is changed from a narrow movable range (-L1 to L1) to a wide movable range (-L2 to L2). As a result, by widening the soft limit value, it is possible to cope with large blurring, and a blur correction effect can be sufficiently obtained.
[0042]
In S170, it is determined whether or not the second timer 63 has expired. The blur correction CPUs 5x and 5y determine whether or not the second timer 63 has timed out. When the second timer 63 has timed out, the process proceeds to S180. During the ON operation of the second timer 63, the target drive position information X is the comparison value X_minIf not, the comparator 54 determines that the blurring is biased in one direction and that the photographer changes the composition, pans, or drifts of the angular velocity sensors 2x and 2y. If the movable range of the vibration reduction lens 10 is changed to a wide movable range (-L2 to L2) during composition change or panning by the photographer, the movement of the image is delayed with respect to the movement of the photographer, and the photographer feels uncomfortable. Will be given. For this reason, the comparator 54 does not change the soft limit value of the movable range limiter 55. When the second timer 63 has not timed out, the process returns to S150, and the comparator 54 determines that the target drive position information X is the comparison value X._maxIt is repeatedly determined whether or not the value is below.
[0043]
In S180, the second timer 63 is turned off, and in S190, the first timer 62 is reset. In S130, the comparator 54 determines that the target drive position information X is the comparison value X._maxIt is repeatedly judged whether or not it is exceeded again.
[0044]
In S200, the comparator 54 determines that the target drive position information X is the comparison value X._minOr less. Target drive position information X is comparison value X_maxAnd the comparison value X_minWhen the value is less than S, the process proceeds to S210, and the target drive position information X is compared with the comparison value X._maxAnd the comparison value X_minIf not, the process proceeds to S270.
[0045]
In S210, the second timer 63 is turned on. In S220, the comparator 54 determines that the target drive position information X is the comparison value X._maxIt is judged whether it is larger than. Target drive position information X is comparison value X_maxIf it is larger, the process proceeds to S230. In S230, the soft limit value can be set from ± L1 to ± L2 to deal with a large blur. On the other hand, the target drive position information X is the comparison value X_maxWhen it falls below the value, the process proceeds to S240. In this case, the movable range limiter 55 does not change the soft limit value due to composition change by the photographer, panning, or drift of the angular velocity sensors 2x and 2y. In S240, it is determined whether the second timer 63 has expired. If the second timer 63 has not timed out, the process returns to S220.
[0046]
In S250, the second timer 63 is turned off, and in S260, the first timer 62 is reset. In S130, the comparator 54 determines that the target drive position information X is the comparison value X._maxIt is repeatedly judged whether or not it is larger than the above.
[0047]
In S270, it is determined whether or not the first timer 62 has timed out. The blur correction CPUs 5x and 5y determine whether or not the first timer 62 has timed out. When the first timer 62 has timed out, the process proceeds to S280, and when the first timer 62 has not timed out, the process proceeds to S290.
[0048]
In S280, the soft limit is set to ± L1. When the movable range limiter 55 extends the soft limit value to ± L2 and no significant blur is input during the ON operation of the first timer 62 (before timeout), the movable range limiter 55 From ± L2 to ± L1. The movable range of the vibration reduction lens 10 is returned from the wide movable range (−L2 to L2) to the narrow movable range (−L1 to L1) so that the photographer does not feel uncomfortable even if panning or composition change is performed.
[0049]
In S290, it is determined whether or not the full push switch has been turned ON. When the full push switch is turned on, the process proceeds to S300, and when the full push switch is not turned on, the process proceeds to S310.
[0050]
In S300, the soft limit is set to ± L2. In the middle of this flow, when the release switch 60 is fully pressed, the soft limit value is expanded from ± L1 to ± L2. A wider movable range (correction range) of the blur correction lens 10 is more advantageous as a shooting result during a shooting operation. For this purpose, the movable range limiter 55 prepares for exposure by changing the movable range of the blur correction lens 10 from a narrow movable range (-L1 to L1) to a wide movable range (-L2 to L2).
[0051]
In S310, it is determined whether the blur correction has been completed. The CPUs 5x and 5y determine whether or not to end the shake correction based on the OFF operation of the shake correction start switch 14 or the time-out of the half-press timer, and end this flow when the shake correction ends. On the other hand, when the shake correction start switch 14 is OFF or the half-press timer has not timed out, the process returns to S130, and the target drive position information X is compared with the comparison value X._maxIs repeatedly determined.
[0052]
In the shake correction apparatus according to the first embodiment of the present invention, immediately after the power is turned on, the movable range of the shake correction lens 10 is set to a narrow movable range (-L1 to L1) by the movable range limiter 55. For this purpose, the blur correction lens 10 is driven, for example, at or near the optical axis I that is the center of the movable range. As a result, when the photographer changes the composition or pans, the blur correction lens 10 is largely driven by the blur correction operation, so that the image in the finder does not move or the image in the finder follows with a delay. Can be solved.
[0053]
Further, during the ON operation of the second timer 63, the comparison value X in which the target drive position information X is the maximum set value._maxAnd the comparison value X is the minimum set value_minWhen the value is less than, the movable range limiter 55 is changed from the narrow movable range (-L1 to L1) to the wide movable range (-L2 to L2). For this reason, when a large blur that exceeds a narrow movable range (-L1 to L1) is input, the movable range of the blur correction lens 10 is widened to correct the blur within a wide movable range (-L2 to L2). be able to.
[0054]
Further, after the change to the wide movable range (−L2 to L2) and during the ON operation of the first timer 62, the target drive position information X is compared with the comparison value X._maxAnd the comparison value X_minWhen the value does not fall below, the movable range limiter 55 has returned to the narrow movable range (-L1 to L1). For this reason, when a large blur is not input, the movable range limiter 55 quickly changes from a wide movable range (-L2 to L2) to a narrow movable range (-L1 to L1) for panning or composition change by the photographer. Can respond.
[0055]
(Other embodiments)
It is not limited to embodiment described above, A various deformation | transformation and change are possible, and they are also in the equivalent range of this invention.
For example, in the shake correction apparatus according to the first embodiment of the present invention, the overflow prevention table 52, the position bias table 56, and the speed bias table 57 are discontinuous tables. The same effect can be obtained. In addition, the soft limit value is a binary value of ± L1 and ± L2, but by providing a plurality of comparison values, the movable range of the blur correction lens 10 can be changed to a plurality of ranges from a narrow movable range to a wide movable range. It can also be changed. Furthermore, the soft limit ± L2 can be omitted, and the outside can be used as a mechanical limit.
[0056]
The shake correction apparatus according to the first embodiment of the present invention includes a target drive position signal X and a comparison value X._max, X_minAre compared by the comparator 55, but the present invention is not limited to this. For example, the output signals of the angular velocity sensors 2x and 2y and the comparison value X_max, X_minAnd the soft limit of the movable range limit 55 can be changed based on the comparison result. In addition, the blur correction apparatus according to the first embodiment of the present invention has been described by taking the case of being mounted on a single-lens reflex camera as an example, but the present invention can also be applied to a video camera, binoculars, and the like.
[0057]
【The invention's effect】
As described above in detail, according to the present invention, the movable range restricting unit can change the movable range based on the shake detection signal or the target position signal. For this reason, by first setting the movable range to be narrow, framing that does not give the photographer a sense of incongruity becomes possible. Further, by setting the movable range wide, the effect of blur correction can be sufficiently obtained even when excessive blur occurs.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a state in which a shake correction apparatus according to a first embodiment of the present invention is mounted on a single-lens reflex camera.
FIG. 2 is a block diagram of a shake correction apparatus according to the first embodiment of the present invention.
FIG. 3 is a block diagram of a calculation unit of a shake correction CPU in the shake correction apparatus according to the first embodiment of the present invention.
FIG. 4 is a diagram showing an overflow prevention table in the shake correction apparatus according to the first embodiment of the present invention.
FIG. 5 is a block diagram of a control unit of a shake correction CPU in the shake correction apparatus according to the first embodiment of the present invention.
FIG. 6 is a diagram showing a position bias table in the shake correction apparatus according to the first embodiment of the present invention.
FIG. 7 is a diagram showing a speed bias table in the shake correction apparatus according to the first embodiment of the present invention.
FIG. 8 is a flowchart illustrating the operation of the shake correction apparatus according to the first embodiment of the present invention.
FIG. 9 is a diagram illustrating the operation of the shake correction apparatus according to the first embodiment of the present invention.
[Explanation of symbols]
2x, 2y angular velocity sensor
3x, 3y VCM (voice coil motor)
5x, 5y image stabilization CPU
10 Vibration reduction lens
53 Ideal target position converter
54 Comparator
55 Movable range limiter
56 Position bias table
57 Speed bias table
58 PID controller
I Optical axis
-L1 to L1 Narrow range of motion
-L2 to L2 Wide movable range
X Target drive position signal
X_max, X_min  Comparison value
ω Angular velocity information

Claims (6)

A shake detection unit that detects a shake and outputs a shake detection signal;
An image stabilization optical system for correcting image blur,
A drive unit for driving the blur correction optical system;
A movable range setting unit that sets a movable range of the blur correction optical system to a first range ;
When the shake based on the shake detection signal is determined to be larger than the predetermined range, the movement range change unit that changes the movable range in the wide second range from said first range,
Shake correction apparatus characterized by comprising a. A shake detection unit that detects a shake and outputs a shake detection signal;
An image stabilization optical system for correcting image blur,
A drive unit for driving the blur correction optical system;
A target drive position calculator that calculates a target drive position of the shake correction optical system based on the shake detection signal and outputs a target position signal;
A movable range setting unit that sets a movable range of the blur correction optical system to a first range ;
If the blur based on the target position signal is determined to be larger than the predetermined range, the movement range change unit that changes the movable range in the wide second range from said first range,
Shake correction apparatus characterized by comprising a. The blur correction device according to claim 1 or 2 ,
Based on the blur detection signal or the target position signal, a control unit that drives and controls the driving unit,
When the movable range is the first range, the control unit causes the drive unit to drive the blur correction optical system at or near the center of the movable range;
A blur correction device characterized by the above. The blur correction device according to claim 1 or 2 ,
Comparing the blur detection signal or the target position signal with a comparison value,
The comparison value includes a maximum setting value and a minimum setting value, and the movable range changing unit causes the comparison unit to cause the blur detection signal or the target position signal to exceed the maximum setting value within a set time, and When it is determined that the value is below a minimum set value, the movable range is set to the second range ;
A blur correction device characterized by the above. The blur correction device according to claim 4 ,
The movable range changing unit, after changing the movable range to the second range , the shake detection signal or the target position signal does not exceed the maximum set value within a set time, and the minimum set value when not fall below shall be cause returning the movable range in the first range,
A blur correction device characterized by the above. In the blurring correction apparatus according to any one of claims 1 to 5 ,
The movable range changing unit is configured to change the movable range to the second range during a photographing operation;
A blur correction device characterized by the above.

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