JPH11218795A - Camera with shake correcting function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce unpleasant vibration noise generated when shake correcting effect is confirmed through a finder by providing a control means which controls a correcting optical element by using the detection signal from a shake detecting means and a means which switches the control method of the control means before and after the start of exposure of an image recording medium. SOLUTION: A microcomputer 12 judges whether or not a 2nd switch S2 of a shutter release button 13 is turned ON and when the 2nd switch S2 is turned ON, the microcomputer 12 sets the gain of proportional compensation (P compensation) to the gain |Gp1| of a transfer function Gp again for a PID part 5 and adds derivative compensation (D compensation) to the P compensation to perform an exposure sequence. In this case, vibration noise generated by a correction optical part 11 of the shake correcting device is large, but the operation time of the shake correcting device in the exposure is short and the operation noise of the lifting of a mirror, the winding of a film, etc., is loud, so the vibration noise generated by the correction optical part 11 is hidden behind those operation sounds and a user does not feel unpleasant so much.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a camera having a shake correction function, and more particularly to a camera shake correction control in which a shake correction effect can be confirmed by a finder or a liquid crystal display.

[0002]

2. Description of the Related Art A camera having a shake correcting function has an advantage that a shake correcting effect can be confirmed by a finder or a liquid crystal display before recording an image on an image recording medium such as a silver halide photographic film or a CCD solid-state imaging device. . FIG. 9 shows a block configuration of a conventional shake correction device in a camera having a shake correction function.

[0003] In the conventional shake correction apparatus shown in FIG.
The angular velocity sensor 1 detects vibration (hereinafter, referred to as “vibration”) applied to the lens barrel or the camera body due to camera shake of the user or the like, and outputs the detected vibration to the high-pass filter (HPF) unit 2 as an angular velocity signal. . The angular velocity sensor 1 excites an angular velocity detecting unit at a high frequency (usually a frequency in an ultrasonic region) by using, for example, a piezoelectric element, and detects a Coriolis force generated by a rotational motion component of the excitation velocity and the vibration, thereby detecting the vibration. Detect angular velocity. The high-pass filter (HPF) unit 2 removes a DC drift and an offset included in the angular velocity signal from the angular velocity sensor unit 1, and the integration unit 3 integrates the angular velocity signal passed through the high-pass filter 2 and converts it into an angle signal.

[0004] In the shake correction, a correction optical element (correction lens) 8 is driven by a drive element 7 in order to cancel a change in the position of the subject image on the film surface or the image pickup plane due to the shake (hereinafter, referred to as "shake amount"). By moving the imaging lens in a direction orthogonal to the optical axis of the imaging lens. Therefore, the level setting unit 4 adjusts the level of the angle signal and converts it into a corrected position control signal in order to determine the moving amount of the correcting optical element 8 or the position to be moved (corrected position). Level setting section 4
Is determined in advance in accordance with the focal length of the imaging lens, and is input from the microcomputer (microcomputer) 12 to the level setting unit 4. Further, the position of the correction optical element 8 (the position in the direction orthogonal to the optical axis)
Is detected by the position sensor unit 9. The correction optical unit 11 includes a correction optical element 8, a driving element 7, and a driving element 7.
And a mechanism for transmitting the output of the drive element 7 to the correction optical element 8 and a position sensor 9.

In order to improve the accuracy of shake correction, feedback control is performed to feed back the position information of the correction optical element 8 from the position sensor unit 9 to the correction position control signal from the level setting unit 4. PID unit 5 described later,
The drive unit 6, the drive element 7, the correction optical element 8, the position sensor unit 9, and the subtraction unit 10 for driving the drive element 7 form a feedback loop.

The subtraction section 10 subtracts the corrected position detection signal of the position sensor section 9 from the corrected position control signal of the level setting section 4. The PID unit 5 performs P compensation (proportional compensation), I compensation (integral compensation), and D compensation (differential compensation) on the output signal from the subtraction unit 10, and performs a delay transfer characteristic (the driving element 7) of the correction optical unit 11. (A transmission characteristic from the correction optical element 8 to the correction optical element 8). Note that the characteristics of the driving unit 6 and the position sensor unit 9 are good, and there is no particular problem.

Generally, in feedback control, PID
A control method called control is used. The D compensation (differential compensation) is used to improve the reduction of the gain margin GM and the phase margin PM due to the overcompensation of the P compensation (proportional compensation), and to improve the stability of the feedback control. I compensation (proportional compensation) is used to improve the offset characteristics of feedback control. Feedback control using these P compensation, I compensation, and D compensation selected and combined as necessary is called PID control.

[0008] The correction optical element 8 uses a concave lens or a convex lens to move the optical axis in a direction orthogonal to the optical axis of the imaging lens by the driving element 7 or an optical element that can change the refraction direction of light. An element is known in which an element is used, the refraction direction of which is shifted by a driving element 7 to cancel the vibration. As the driving element 7, a DC motor, a voice coil motor, an ultrasonic motor or the like is used. Drive unit 6
Is a constant voltage drive as appropriate according to the operating characteristics of the drive element 7;
Constant current driving, pulse width modulation driving (PWM driving) and the like are employed.

For example, in the case of a camera using a silver halide film, the shutter release button 13 of the camera body is configured such that the first switch S1 and the second switch S2 are sequentially turned on in accordance with the amount of depression. The first switch S1 is turned on when the shutter release button 13 is depressed about halfway.
When 1 is turned on, a series of exposure preparation sequences such as measurement of subject brightness (photometry), focusing of the imaging lens on the subject (distance measurement), and shake correction operation are started. The second switch S2 is turned on when the shutter release button 13 is fully depressed, and the microcomputer 12 switches the second switch S2
The exposure sequence such as up / down of a mirror, aperture operation of an imaging lens, opening / closing of a shutter, winding of a film, etc. is performed by turning on.

The actual shake correction is performed by using two sets of the above-described shake correction devices, and correcting the image shake in two directions (pitch direction and yaw direction with respect to the optical axis of the imaging lens) orthogonal to each other on the film surface. Correct each.

[0011]

In general, it is known that the correction optical section 11 generates a vibration sound when the correction optical element 8 is feedback-controlled. As described above, the PDI control is generally used for the feedback control. Among them, the D compensation (differential compensation) decreases the gain margin GM and the phase margin PM due to the overcompensation of the P compensation (proportional compensation). However, at the same time, the high-frequency component of noise included in the corrected position control signal and the output signal of the position sensor unit 9 is emphasized in the feedback loop. Therefore, the driving element 7 vibrates in response to the high frequency component of the emphasized noise,
Further, the vibration of the driving element 7 is transmitted to the correction optical element 8, and the entire correction optical unit 11 generates a vibration sound.

For example, as shown in FIG. 4 (a), a P-combination of P-compensation (proportional compensation) and D-compensation (differential compensation)
In the case of D control, the gain | Gpd |
It is increased in the high frequency region, which is the compensation region. Therefore, for the above reason, the high frequency component of the noise is also amplified and applied to the correction optical unit 11, and the correction optical unit 11 vibrates in response to the corner with respect to the high frequency component of the noise to generate a high-level vibration sound. .

[0013] Therefore, when checking the shake correction effect with the viewfinder of the camera, in the conventional shake correction control, when a high-level vibration sound caused by the feedback control is generated, the user is given an auditory discomfort. Had a point.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and has a vibration correction function similar to the conventional one, and reduces unpleasant vibration sound when checking the vibration correction effect with a finder. It is an object of the present invention to provide a camera having a shake correction function.

[0015]

SUMMARY OF THE INVENTION In order to achieve the above object, a camera having a shake correction function according to the present invention has a shake detecting means and an optical axis of an image pickup lens which is decentered to form an image on an image recording medium. Correction optical element for moving the position of the subject image, driving means for driving the correction optical element, control means for controlling the correction optical element via the driving means using a detection signal from the shake detecting means, and an image recording medium Control method switching means for switching the control method of the control means before the start of the exposure and after the start of the exposure.

In the above arrangement, there are provided first and second switches which are sequentially turned on by operating the operation member, and a first control method before the start of exposure is set by turning on the first switch which is turned on first, and then turned on later. The second control method after the start of exposure may be set by turning on the second switch.

Also, the vibration sound generated by the correction optical element that is generated by the first control method is smaller than the vibration sound generated by the second method, and the vibration correction performance of the second control method is the first.
The control method may be configured to be superior to the shake correction performance.

Alternatively, the noise included in the signal applied to the driving means by the first control method is smaller than the noise by the second method, and the shake correction performance of the second control method is smaller than that of the first control method. You may comprise so that it may be excellent in correction performance.

As a control method, PID control in which proportional compensation (P compensation), integral compensation (I compensation), and differential compensation (D compensation) are selectively combined is used. Before the start of exposure, only proportional compensation is used. The control may be performed, and after the start of the exposure, the control may be performed by controlling the proportional compensation and the differential compensation or the integral compensation, or the combination of the differential compensation and the integral compensation.

Alternatively, as a control method, PID control in which proportional compensation, integral compensation, and differential compensation are selectively combined is used. Before exposure is started, control is performed using only proportional compensation or a combination of proportional compensation and integral compensation. After the start of exposure, a differential compensation may be added to these compensations for control.

Further, in each of the above configurations, control is performed by adding a feedforward compensation function to the PID control.
Before starting exposure, do not use the feedforward compensation function.
After the exposure is started, the feedforward function may be used.

According to such a configuration, when the shake correction effect is confirmed through the viewfinder or the liquid crystal display before the exposure of the image recording medium is started, a control method in which the shake correction performance is slightly inferior but the vibration sound is small is selected. However, it is possible to select a control method which is excellent in the shake correction performance even if the vibration sound is slightly large during the exposure. Here, at the stage before the start of exposure, when observing a subject image through a finder or the like, there is no operation sound of a shutter or the like, so that the vibration sound from the shake correction device may be annoying. Therefore, it is preferable that the vibration sound of the shake correction device be smaller. At this stage, since exposure is not actually performed, there is no particular problem even if the shake correction performance is slightly inferior.

On the other hand, after the exposure starts, relatively loud sounds such as a mirror up / down sound, a shutter operation sound, and a film winding sound are continuously heard. For this reason, even if the vibration sound generated by the shake correction device is slightly loud, the vibration sound is buried in these operation sounds that are even larger. In addition, since the time required for exposure, film winding, and the like is generally very short, even if the operation sound is loud, it does not cause much discomfort to the user.

[0024]

(First Embodiment) A first embodiment of the present invention.
The embodiment will be described with reference to FIGS. 1 to 6. FIG. 1 is a block diagram of a shake correction apparatus according to the first embodiment, which is basically the same as the conventional example shown in FIG.

As shown in FIG. 1, the angular velocity sensor 1 detects a shake and outputs a high-pass filter (HP) as an angular velocity signal.
F) Output to section 2. High-pass filter (HPF) unit 2
Removes a DC drift and an offset included in the angular velocity signal from the angular velocity sensor unit 1, and the integrating unit 3 integrates the angular velocity signal passed through the high-pass filter 2 and converts it into an angular signal. The level setting unit 4 determines a moving amount of the correction optical element 8 or a position to be moved (correction position).
The level of the angle signal is adjusted and converted into a corrected position control signal. The level set by the level setting unit 4 is determined in advance according to the focal length of the imaging lens, and is input from the microcomputer 12 to the level setting unit 4. The position of the correction optical element 8 (the position in the direction orthogonal to the optical axis) is detected by the position sensor 9. Also,
The correction optical unit 11 includes a correction optical element 8, a driving element 7,
It comprises a mechanism member for holding the drive element 7 and transmitting the output of the drive element 7 to the correction optical element 8, and a position sensor unit 9.

The PID section 5, the drive section 6 for driving the drive element 7, the drive element 7, the correction optical element 8, the position sensor section 9, and the subtraction section 10 constitute a feedback loop.
The subtraction unit 10 subtracts the corrected position detection signal of the position sensor unit 9 from the corrected position control signal of the level setting unit 4. PID
The section 5 performs proportional compensation (P compensation), integral compensation (I compensation), and differential compensation (D compensation) on the output signal from the subtraction section 10.
To compensate for the delay transmission characteristic of the correction optical unit 11 (the transmission characteristic from the driving element 7 to the correction optical element 8).

The shutter release button 1 of the camera body
Reference numeral 3 denotes a configuration in which the first switch S1 and the second switch S2 are sequentially turned on in accordance with the pushed amount.
The first switch S1 is turned on when the shutter release button 13 is depressed about halfway, and the microcomputer 12 measures the subject brightness (photometry) by turning on the first switch S1.
A series of exposure preparation sequences, such as focusing (ranging) of the imaging lens on a subject and a shake correction operation, are started. Second
The switch S2 is turned on when the shutter release button 13 is depressed to the end, and the microcomputer 12 turns on the second switch S2 to perform exposure such as mirror up / down, imaging lens aperture operation, shutter opening / closing, film winding, and the like. Perform the sequence. Also, the microcomputer 12
A signal for switching the characteristics (shake correction control method) of the PID unit 5 is sent to the PID unit 5 according to the case where the first switch S1 is on and the case where the second switch S2 is on.
Output to This point is different from the conventional example.

In actual camera shake correction, two sets of the above-described shake correction devices are used, and images in two directions (pitch direction and yaw direction with respect to the optical axis of the imaging lens) orthogonal to each other on the film surface. Is corrected.

Next, a specific embodiment of the feedback control in the PID unit 5 will be described.

[0030]

Embodiment 1 First, among the feedback control, PD control using P compensation (proportional compensation) and D compensation (differential compensation) will be described. FIGS. 2A and 2B show the frequency characteristics of the gain | G1 | and the phase ΔG1 of the transfer function G1 (input signal versus output position) of the correction optical unit 11, respectively.

As can be seen from FIG. 2A, in general, in a target feedback control frequency band (a band in which a margin of about several times to about 10 times the fluctuation frequency band), the gain | G1 | The first-order lag characteristic decreases in proportion to (the logarithm of), the second-order lag characteristic decreases in inverse proportion to the square of the frequency f, and the tertiary delay characteristic decreases in inverse proportion to the third power of the frequency f. In such a second-order lag region and a third-order lag region, P compensation (proportional compensation) is applied to the transfer characteristic of the correction optical unit 11.
When the gain | G1 | is increased, FIG.
As shown in (a), the closed loop gain transfer function G2p1
The peak T near the cutoff frequency of the gain | G2p1 |
Appears. The transfer function Gp of P compensation (proportional compensation) at this time
Is | Gp1 |. This phenomenon indicates that the gain margin GM and the phase margin PM of the feedback control are small, and unnecessary overshoot and ringing occur in the response characteristic, and an oscillation phenomenon such as hunting appears in some cases. Therefore, as shown in FIG.
The P compensation is reduced so that response characteristics such as overshoot are within an allowable range. Transfer function G of P compensation at this time
The gain of p is | Gp2 |. Normal | Gp1 |> | Gp2 |
Since the loop gain is small, sufficient control performance cannot be obtained in many cases. 3A and 3B, the cutoff frequency (feedback control frequency band) of the closed loop gain | G2p2 | is lower than that of the closed loop gain | G2p1 |.

In general, in feedback control, P compensation (proportional compensation) and D compensation (differential compensation) are combined to improve operation instability when the P compensation gain is equal to | Gp1 |. Margin GM and phase margin PM
Is increasing. FIGS. 4A and 4B show frequency characteristics of the gain | Gpd | of the transfer function Gpd and the phase ΔGpd of the correction optical unit 11 in the PD control, respectively.

The PD compensation is obtained by adding D compensation to P compensation and
By giving the next or higher advance characteristic, the apparent correction optical unit 11 can be apparently set within the feedback control frequency band.
Can be improved by the order (first order or more) (| G2pd | shown by a broken line in FIG. 3A).
See characteristics). With this effect, the gain margin GM and the phase margin PM can be increased, and the above-mentioned unstable operation can be improved.

By applying the PD compensation as described above to the correction optical unit 11, control characteristics such as expansion of the feedback control frequency band and increase of the feedback amount (feedback amount) can be improved, and excellent vibration correction can be achieved. The effect can be exhibited.

The operation of the image stabilizing apparatus according to this embodiment configured as described above will be described with reference to the flowchart shown in FIG. First, when the main switch of the camera is turned on (step # 1), the microcomputer 12 determines whether or not the first switch S1 is turned on (step # 1).
3). If the first switch S1 is ON (YES in step # 3), the microcomputer 12 sets the gain of the P compensation to the PID unit 5 to | Gp2 | (step # 5), and does not select the D compensation. The exposure preparation sequence is started while operating the shake correction device only by compensation (step # 7).

At this stage, the user can confirm the shake correction effect through the viewfinder. However, in this operation mode, the vibration sound of the correction optical unit 11 is small, so that there is not much discomfort in hearing. Also. Although the shake correction performance is not sufficient, it does not actually expose the image recording medium, and thus does not hinder the operation check.

Next, the microcomputer 12 determines whether or not the second switch S2 has been turned on (step # 9). If the second switch S2 is on (YES in step # 9), the microcomputer 12 sets the PID section 5 The gain of P compensation is | Gp1 |
Is set again (step # 11), the D compensation is added to the P compensation, and the exposure sequence is executed (step # 13).
When the exposure sequence is executed and the exposure of the image on the image recording medium is completed (step # 15), the microcomputer 12 determines whether or not the main switch is turned off (step #).
17). If the main switch is off (YES in step # 17), this flow ends. Also,
If the main switch remains on (NO in step # 17), the process returns to step # 3, and determines whether or not the first switch S1 is on, and executes the above flow again.

In this case, the correction optical unit 11 of the shake correction device
Is large, but the operating time of the shake correcting device during exposure is short, and the operating noises such as up and down of the mirror and winding of the film are loud.
The vibration sound due to 1 is buried in these operation sounds, and does not cause much discomfort to the user. On the other hand, since the shake correction performance by PD compensation is sufficient, an image with a small shake amount is exposed on the image recording medium.

[0039]

Embodiment 2 Next, integral compensation (I compensation) is added to the PD control.
The following describes PID control with. Gain | G of transfer function Gpid of correction optical unit 11 in PID control
6 (a) and 6 (b) show the frequency characteristics of pid | and the phase ∠Gpid, respectively.

In the PID control, the offset characteristic of the feedback control is improved by adding I compensation to the PD control. However, D compensation (differential compensation)
Similarly to the case (1), the noise component included in the corrected position control signal from the level setting unit 4 and the corrected position signal from the position sensor unit 9 is also enhanced by the I compensation (integral compensation). However, as is apparent from the figure, since the I compensation is performed in a low frequency region, the frequency of the vibration sound due to the I compensation is low, and there are many cases in which the user is not noticeably audible.

In the exposure preparation sequence in the second embodiment, P compensation (proportional compensation) is performed in the same manner as in the first embodiment.
The image stabilization device may be controlled using only the P compensation and the P compensation and the I compensation may be used in combination. On the other hand, in the exposure sequence, PID control combining P compensation, I compensation, and D compensation is performed.

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIG. FIG.
FIG. 6 is a block diagram of a shake correction apparatus according to a second embodiment. Note that components denoted by the same reference numerals as those of the shake correction apparatus of the first embodiment shown in FIG. 1 are substantially the same.

In the second embodiment, feedforward compensation is added to PID control using P compensation (proportional compensation), I compensation (integral compensation) and D compensation (differential compensation). As shown in FIG. 7, the feedforward section (FF section) 14 is connected in parallel to the subtraction section 10 and the PID section 5, and an output from the FF section 14 is provided between the PID section 5 and the driving section 6. An adder 15 for adding the signal and the output signal from the PID unit 5 is provided. The microcomputer 12
To the FF unit 14 during the exposure preparation sequence.
A signal for not selecting the feedforward compensation by the unit 14 is output.

The transfer characteristic of the FF unit 14 is
Has a function of compensating for the delay characteristic of the signal, that is, a lead characteristic (differential characteristic). Therefore, the signal input to the FF unit 14,
That is, the high-frequency component of noise included in the correction position control signal that is the output signal of the level setting unit 4 is increased by the differential characteristics of the FF unit 14 and applied to the correction optical unit 11, so that the correction optical unit 11 vibrates, Generates vibration noise. As a countermeasure, as described above, during the exposure preparation sequence, the image stabilizing device is controlled only by P compensation without selecting feedforward compensation, and during the exposure sequence, P compensation (proportional compensation) and I compensation (integration) by the PID unit 5 are performed. Compensation) and D compensation (differential compensation), and feedforward compensation by the FF unit 14 is used.

(Third Embodiment) Next, a third embodiment of the present invention will be described with reference to FIG. FIG.
FIG. 9 is a block diagram of a shake correction apparatus according to a third embodiment. Note that components denoted by the same reference numerals as those of the shake correction apparatus of the first embodiment shown in FIG. 1 are substantially the same.

In the third embodiment, the moving speed of the correction position of the correction optical element 8 (the position of the optical axis of the correction lens) is detected by the speed sensor unit 17, and the output signal of the speed sensor unit 17 is detected by the PID unit 5. It is configured to feed back to an output signal. To subtract the output signal of the speed sensor unit 17 from the output signal of the PID unit 5, a subtraction unit 16 is provided between the PID unit 5 and the driving unit 6. Further, a signal is output from the microcomputer 12 to the speed sensor unit 17 so as not to select the feedback by the speed sensor unit 17 during the exposure preparation sequence.

By using a speed sensor having a good S / N characteristic (having a differential characteristic with respect to the position) as the speed sensor unit 17, the DID compensation (differential compensation) by the PID unit 5 or complementary to the D compensation is used. In addition, the gain margin GM and the phase margin PM in the feedback control can be improved.

The high frequency component of the noise included in the moving speed signal of the correction position of the correction optical element 8 is increased by the differential characteristic of the speed sensor section 17 and applied to the correction optical section 11. Vibrates, generating a vibrating sound. Therefore, in the case of the exposure preparation sequence, the microcomputer 12 sets the gain of the P compensation for the PID unit 5 to | Gp2 |, does not select the D compensation, and operates the shake correction device only with the P compensation to prepare for the exposure. Execute the sequence. In the case of the exposure sequence, the microcomputer 12
, The gain of P compensation is reset to | Gp1 |, and the feedback sequence by the speed sensor unit 17 or the D compensation and the feedback by the speed sensor unit 17 is added to the P compensation to execute the exposure sequence.

(Other Embodiments) In the above embodiment,
Although the description has been made using a single-lens reflex camera using silver halide photographic film as an example, the present invention is not limited to this. The present invention is also applied to a digital camera or a video camera that reproduces an image formed by an imaging lens on a liquid crystal display or the like. It is possible to apply the invention.

[0050]

As described above, the camera having the shake correcting function according to the present invention is capable of detecting the position of the subject image formed on the image recording medium by decentering the optical axis of the shake detecting means and the imaging lens. A correcting optical element to be moved, a driving means for driving the correcting optical element, a control means for controlling the correcting optical element via the driving means using a detection signal from the shake detecting means, and before the exposure of the image recording medium is started. Since a control method switching means for switching a control method of the control means after the start of exposure is provided, when the shake correction effect is confirmed through a finder or a liquid crystal display or the like before the exposure of the image recording medium is started, the shake correction performance is slightly reduced. It is possible to select a control method which is inferior but has a small vibration sound, and selects a control method which is excellent in shake correction performance even if the vibration sound is slightly large during exposure. Here, at the stage before the start of exposure, when observing a subject image through a finder or the like, there is no operation sound of a shutter or the like, so that the vibration sound from the shake correction device may be annoying. Therefore, it is preferable that the vibration sound of the shake correction device be smaller. At this stage, since exposure is not actually performed, there is no particular problem even if the shake correction performance is slightly inferior. On the other hand, after the exposure starts, relatively loud sounds such as a mirror up / down sound, a shutter operation sound, and a film winding sound are continuously heard. For this reason, even if the vibration sound generated by the shake correction device is slightly loud, the vibration sound is buried in these operation sounds that are even larger.
In addition, since the time required for exposure, film winding, and the like is generally very short, even if the operation sound is loud, it does not cause much discomfort to the user.

[Brief description of the drawings]

FIG. 1 is a block diagram of a shake correction apparatus according to a first embodiment of the present invention.

2A is a diagram illustrating a frequency characteristic of a gain | G1 | of a transfer function G1 (input signal versus output position) of the correction optical unit 11, and FIG. 2B is a diagram illustrating a frequency characteristic of a phase ΔG1 thereof. FIG.

3A is a diagram illustrating frequency characteristics such as gain | Gp1 | of a closed-loop gain transfer function Gp1 when P compensation (proportional compensation) is performed on the transfer characteristics of the correction optical unit 11, and FIG. FIG. 9 is a diagram showing a frequency characteristic of a gain | Gp2 | of the transfer function Gp when P compensation is suppressed.

4A is a diagram illustrating a frequency characteristic of a gain | Gpd | of a transfer function Gpd of the correction optical unit 11 in PD control, and FIG. 4B is a diagram illustrating a frequency characteristic of a phase ΔGpd thereof.

FIG. 5 is a flowchart illustrating an operation of the shake correction apparatus according to the first embodiment.

FIG. 6A shows a correction optical unit 11 in PID control.
FIG. 6 is a diagram showing the frequency characteristics of the gain | Gpid | of the transfer function Gpid of FIG.

FIG. 7 is a block diagram of a shake correction apparatus according to a second embodiment of the present invention.

FIG. 8 is a block diagram of a shake correction apparatus according to a third embodiment of the present invention.

FIG. 9 is a block diagram of a conventional shake correction apparatus.

[Explanation of symbols]

1: angular velocity sensor unit (vibration detecting unit) 2: high-pass filter (HPF) unit 3: integrating unit 4: level setting unit 5: PID unit 6: driving unit (driving unit) 7: driving element (driving unit) 8: correction Optical element 9: Position sensor section 10: Subtraction section 11: Correction optical section 12: Microcomputer (microcomputer: control means, control method switching means) 13: Shutter release button (operation member) 14: Feedforward section 15: Addition section 16 : Subtractor 17: Speed sensor S1: First switch S2: Second switch

Claims (7)

[Claims] 1. A shake detecting means, a correcting optical element for decentering an optical axis of an imaging lens and moving a position of a subject image formed on an image recording medium, and a driving means for driving the correcting optical element. Control means for controlling the correction optical element via the driving means, using a detection signal from the shake detection means, and control method switching means for switching the control method of the control means before and after the exposure of the image recording medium is started. A camera having a shake correction function comprising: 2. A first switch which is sequentially turned on by operating an operation member.
And a second switch. A first control method before the start of exposure is set by turning on a first switch that is turned on first, and a second control method after exposure is started by turning on a second switch that is turned on later. The camera having a shake correction function according to claim 1, wherein the camera is set. 3. The vibration sound generated by the correction optical element, which is generated by the first control method, is smaller than the vibration sound generated by the second method, and the shake correction performance of the second control method is different from that of the first control method. The camera having a shake correction function according to claim 1, wherein the camera has better shake correction performance. 4. The noise included in a signal applied to the driving means by the first control method is smaller than the noise by the second method, and the shake correction performance of the second control method is smaller than that of the first control method. The camera having a shake correction function according to claim 1, wherein the camera has better correction performance. 5. A control method using PID control selectively combining proportional compensation, integral compensation and differential compensation,
2. The swing according to claim 1, wherein the control is performed using only proportional compensation before the start of the exposure, and the control is performed after the start of the exposure by a combination of the proportional compensation and the differential compensation or the integral compensation or the combination of the differential compensation and the integral compensation. Camera with correction function. 6. A control method using PID control selectively combining proportional compensation, integral compensation, and differential compensation,
2. The swing according to claim 1, wherein the control is performed by using only the proportional compensation or a combination of the proportional compensation and the integral compensation before the exposure is started, and the control is performed by adding the differential compensation to the compensation after the exposure is started. Camera with correction function. 7. A control in which a feed forward compensation function is added to PID control, wherein the feed forward compensation function is not used before the start of exposure, and the feed forward function is used after the start of exposure. Or a camera having a shake correction function according to 6.