JP2003043544A - Vibration-proof system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the vibration-proof accuracy by always controlling vibra tion proof based on actual vibration. SOLUTION: The vibration-proof system is provided with first vibration detection means 104, 106, 105, and 107 which detect vibration of the system, second vibration detection means 118, 119, and 120 which detect the vibration by a method other than that of the first vibration detection means, and a vibration correction means which corrects the vibration on the basis of outputs of the first vibration detection means and the second vibration detection means, and the vibration is corrected on the basis of only outputs of the second vibration detection means till a prescribed time passes after the start of exposure operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a vibration isolation system having first and second shake detecting means for detecting shake by different methods.

[0002]

2. Description of the Related Art Conventionally, a vibration isolator has been known, but a mechanical sensor such as a vibration gyro that detects an angular velocity around a predetermined axis is used as a vibration sensor provided in this type of device. A device of a type that drives a correction optical system configured by the entire surface or a part of the photographing optical system based on the output is general.

Further, the movement calculated from the shake output from the mechanical sensor as described above and the correlation amount between image data at different times, which forms an image on the image sensor provided in the camera body through the optical system. Japanese Patent Laid-Open No. 7-191354 proposes a vibration control device of a type that drives a correction optical system based on a shake output detected by a vector amount.

[0004]

By the way, on the camera body side, a large impact, such as traveling of the shutter, occurs with the exposure operation. In the image stabilization apparatus using the mechanical sensor as the shake sensor as described above, since the correction operation is also performed for the shake due to the shock accompanying the exposure operation, the accuracy of the correction for the camera shake is impaired. There was a flaw.

In order to solve this drawback, JP-A-4-18
In the 1930 publication, a control method is proposed in which when a shake sensor detects a shock such as traveling of a shutter, the shake is not calculated until the sensor output stabilizes, or the shake is corrected using data immediately before the shock. Has been done. Further, in Japanese Patent Laid-Open No. 8-334804,
When the shake caused by the image pickup apparatus occurs, the control for the correction optical system based on the detected shake is interrupted. Further, a control method has been proposed in which, during the interruption, the correction optical system is moved at the moving speed immediately before the interruption of the control.

However, although the above-described control method can prevent the shake sensor and the correction optical system from abnormally responding to the shock caused by the exposure operation of the camera, it does not mechanically respond to the shock. The shake is not corrected at all until the sensor output stabilizes, or it is not based on the actual shake but based on the prediction from the previous shake data, and the shake is corrected according to the actual shake. It was the current situation that I was not told.

(Object of the Invention) It is an object of the present invention to provide an anti-vibration system capable of improving anti-vibration accuracy by always performing anti-vibration control based on actual shake.

[0008]

In order to achieve the above object, the present invention provides a first shake detecting means for detecting a shake of a system, and a shake detecting method different from the first shake detecting means. And a shake correction unit that performs shake correction based on the outputs of the first shake detection unit and the second shake detection unit, and a predetermined time elapses after the exposure operation is started. Until then, the image stabilization system performs the image stabilization based only on the output of the second image stabilization unit.

Specifically, the first shake detecting means for detecting the shake of the system from the angular velocity around a predetermined axis by using the vibrating gyro and the image data at different times for forming an image on the image sensor through the optical system. Among the second shake detecting means for detecting shake from the correlation amount of the above, the former first shake detecting means has a period in which its output gives an abnormal response due to the impact of the exposure member during the exposure operation. Therefore, during this period, the shake is corrected by using the output of the latter second shake detecting means that does not give an abnormal response to the output.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will now be described in detail based on the illustrated embodiments.

FIG. 1 is a block diagram showing a circuit configuration of a main part of a camera provided with a vibration isolation device according to each embodiment of the present invention.

In FIG. 1, reference numeral 101 is a control circuit that controls the entire sequence and shake correction control. The shake output of the shake sensor 104 (detection in the pitch direction), which is a mechanical sensor such as a vibration gyro, is input to the A / D converter 102 through the filter circuit 105, converted into digital data here, and taken into the control circuit 101. Be done. Similarly, the output of the shake sensor 106 (detection in the yaw direction) is
It is input to the A / D converter 102 through the filter circuit 107 and taken in by the control circuit 101 as digital data. In the control circuit 101, an A / D is set at regular intervals.
It has a first sampling timer 108 for timing setting for fetching data from the converter 102 and performing shake correction calculation, and outputs the result of shake correction calculation to the D / A converter 103 based on this timing. . The D / A converter 103 outputs an analog voltage proportional to the input data, and this output voltage is output to the shake correction system drive circuit 111, and the correction lens 113 included in the shake correction system indicates an arrow (pitch, yaw direction). ) Will be driven in the direction shown.

The current position of the shake correction system is detected by the correction system position detection circuit 114, and its output is taken into the control circuit 101 through the A / D converter 102.

On the other hand, incident light from a subject is incident on a semi-transparent main mirror 115 through an optical system such as a photographing lens 112 and a correction lens 113, and its reflected light passes through a prism 116 and a part thereof is a finder optical system. Further, a part of the light is guided to the area sensor 118 that performs photometry and image shake detection through the photometric lens unit 117.

The image information taken in by the area sensor 118 is inputted to the control circuit 101 and the field memory 119. In the control circuit 101, the area sensor 118
Exposure control such as calculation of a shutter speed and an aperture value is performed based on image information directly captured from the. Further, the field memory 119 temporarily stores the image information, and then the motion vector detection circuit 120 calculates the shake vector of the image by the correlation calculation of two different times, and the result is input to the control circuit 101. The shake detection operation from the information is performed at constant cycle intervals based on the second sampling timer 109 incorporated in the control circuit 101. This shake vector is combined with the shake sensor output described above, and D /
It outputs to the A converter 103 and drives the correction lens 113.

In the control circuit 101, in addition to the first and second sampling timers, the image stabilization operation is performed only based on the image information captured by the area sensor 118 until a predetermined time elapses immediately after the start of the exposure operation. ON by pressing the button fully
The third timer 110 for measuring the time from when the switch SW2 (125) to be turned on is incorporated.

Further, a shutter curtain 122 is transmitted via a shutter drive circuit 121 by a control signal from the control circuit 101.
Performs timing control of (first curtain / second curtain).

In addition, the camera has a switch 124 (SW1) which is turned on by pressing the release button of the camera halfway,
In addition, a switch 123 for setting whether or not to perform image stabilization control
(ISSW) is provided.

(First Embodiment) With respect to the camera having the above structure, the operation of the actual camera according to the first embodiment of the present invention will be described with reference to the flow charts shown in FIGS.

FIG. 2 shows a main flow of control of camera operation related to image stabilization control.

In the figure, first, at step # 201, the switch SW1 is turned on by half-pressing the release button.
Switch is turned on and the switch SW
If 1 is ON, then in step # 202 and step # 203, a battery check circuit (not shown) determines whether the power supply voltage is sufficient to guarantee the operation of the entire camera. If it is determined to be sufficient, the process proceeds to step # 204 and the switch SW
It waits until 1 is turned off, and when it is detected that the switch SW1 is turned off, it returns to the START position again.

On the other hand, if the result of the battery check is judged to be OK in step # 203, step # 2
In step 05, the subject brightness is measured from the image captured by the area sensor 118, and AE calculation is performed based on this photometric value to determine the shutter speed and aperture value.

In the following step # 206, focus control is executed by driving an image sensor and a focus lens (not shown). This focus control is continued until the focus can be detected in the next step # 207, and by detecting the focus, the process proceeds to step # 208, and the switch SWIS
Is turned on, the switch turns off.
When the FF is performed, it is determined that the image stabilization operation is not necessary, and the process proceeds to step # 209, where the ISO in the control circuit 101
The NL is reset to 0 and the process immediately proceeds to step # 215.

When it is detected in step # 208 that the switch SWIS is ON, the process proceeds to step # 210, and the shake sensor 10 having a mechanical structure is used.
Energization to 4, 106 is started.

Here, an example of a specific configuration of the shake sensor 104 and the filter circuit 105 (or the shake sensor 106 and the filter circuit 107) having the mechanical configuration of FIG. 1 will be described with reference to the circuit diagram of FIG.

FIG. 5 shows a case where a known vibration gyro is used as a shake sensor, which is composed of a vibration gyro which is an angular velocity sensor and an integrator circuit. The vibration gyro 501 is resonantly driven by a drive circuit 503, and output conversion is performed by a synchronous detection circuit or the like so as to obtain a predetermined angular velocity output. The output from this synchronous detection circuit usually contains an unnecessary DC offset.
The C component is removed by a high-pass filter composed of a capacitor 505 and a resistor 506, and only the remaining shake signal is O.
It is amplified by an amplifier including a P amplifier 504 and resistors 507 and 508. Further, the output of this amplifier is integrated by an integrating circuit composed of an OP amplifier 509, resistors 510 and 511, and a capacitor 512, and is converted into an output proportional to the shake displacement.

Returning to FIG. 2, in the next step # 211, the shake correction system including the correction lens shown in 113 of FIG. 1 is energized to start driving the correction lens 113. Is shown in FIG.

FIG. 6 shows the construction of a so-called shift optical system for correcting the angular shake of the camera by shifting the lens in parallel in the x and y directions perpendicular to the optical axis.

In the figure, reference numerals 601 and 602 denote yoke portions as magnetic circuit units serving as actual driving sources in the x- and y-axis directions, and reference numerals 603 and 604 denote coil portions corresponding to the respective yokes. Therefore, the lens group 605, which is a part of the photographing lens, is eccentrically driven in the x and y directions by the amount and direction of the current flowing through the coil portion, and 606 is a supporting arm and a supporting frame for fixing the lens group 605. Is represented. On the other hand, the movement of the lens group 605 is detected in a non-contact manner by the combination of the IREDs 607 and 608 that move integrally with the lenses and the PSDs 613 and 614 mounted on the barrel 611 for holding the entire shift lens. It

Reference numeral 609 denotes a mechanical lock mechanism for mechanically holding the lens at the optical axis center position substantially at the optical axis center when the power supply to the shift system is stopped, 610 is a charge pin, and 612 is a mechanical lock mechanism. Each of the supporting balls as a tilt stop for controlling the tilt direction of the shift system is shown.

Returning to FIG. 2 again, in step # 212,
In order to perform sampling control of the correction type at constant time intervals based on the shake sensor output described above, the built-in first sampling timer 108 starts the time counting operation. The interrupt processing by the first sampling timer 108 will be described later with reference to the flowchart of FIG. 3. The interrupt processing of FIG. 3 is performed by the steps of the main flowchart of FIG. 2 every time the first sampling timer 108 measures a predetermined time T1. # 21
In the middle of the processing operations after 3, the processing is temporarily interrupted, and the contents of the flowchart of FIG. 3 are preferentially executed.

In the next step, step # 213, the above-mentioned area sensor 118 starts the time-measuring operation of the second sampling timer 109 for detecting the shake amount at regular intervals based on the shake amount of the subject on the image plane. The interrupt processing by the second sampling timer 109 will also be described later with reference to the flowchart of FIG. 4, but every time the second sampling timer 109 measures a predetermined time T2 (> T1), step # of the main flowchart of FIG. In the middle of the processing operation after 213, the processing is temporarily interrupted and the operation of the contents shown in the flowchart of FIG. 4 is preferentially executed.

In the following step # 214, ISONL inside the control circuit 101 indicating that the image stabilization mode is set is set to 1, and in the next step # 215, the switch S is switched.
It is determined whether or not W2 is turned on. If it is still off, the process proceeds to step # 216 and the switch SW1 is turned on.
If it is N, it is determined whether only the switch SW1 is ON, and the process returns to step # 215 again to repeat the above operation.

In step # 216, the switch S
If W1 is off, proceed to step # 217,
ISONL is determined whether or not 1, ISONL
Is 0, it is determined that the image stabilization operation is not performed, the process proceeds to step # 222, the driving of the area sensor 118 is stopped, and the process returns to the START position. On the other hand, if ISONL is 1 in step # 217, it is determined that the image stabilization operation is performed, and in the next step # 218, the drive of the shake correction system is stopped, and the subsequent step # 21.
In # 9 and # 220, the first and second sampling timers are stopped, and in step # 221, the shake sensor is stopped, and then the process proceeds to step # 222.

In step # 215, the switch S
When W2 is turned on and the hair position is reached, the exposure operation starts, but before the actual exposure operation, the next step # 22
Immediately after the exposure operation starts in 3, the shake correction is temporarily performed by the area sensor 1.
In order to perform only based on the image information captured in 18, the built-in third timer 110 for measuring the elapsed time from the ON of the switch SW2 is started. Then, in the subsequent steps # 224 to # 228, the shutter drive circuit 12
The shutter curtain 122 (front curtain and rear curtain) is controlled to travel via 1 to perform the exposure operation for the film. And
In the next step # 229, the time counting operation of the third timer 110 is stopped, the film is fed in step # 230, and then the process returns to step # 215 to complete a series of photographing operations.

Next, using the flow charts shown in FIGS. 3 and 4, the first sampling timer 108 and the second sampling timer 108, respectively.
The interrupt processing by the sampling timer 109 will be described.

When the first sampling timer 108 counts the predetermined time T1, the interrupt processing operation shown in the flowchart of FIG. 3 is executed at that time.

In this interrupt processing, first, in step # 301 of FIG. 3, the first sampling timer 108
After initial resetting the value of, and setting the next sampling timing (to execute interrupt processing again after T1 time), in the next step # 302, the time after performing the shake correction operation last time is set to the internal T register. Set to. Then, in the next step # 303, the area sensor 118
Motion vector detection circuit 120 based on image information of different time
The multiplication result of the value of the V register in which the value corresponding to the image moving speed calculated in step 3 is set and the shake correction control interval set in the T register is set in the B register as the image shake amount.

In the following step # 304, the switch SW
2 is ON, and if it is still OFF, the process proceeds to step # 307 to perform correction using the shake information of both the shake sensor and the area sensor, where the shake sensor output is A / The D-converted value is transferred to the internal A register.

In step # 304, the switch S
If W2 is ON, proceed to step # 305,
Refer to the current value of the third timer 110 in the control circuit 101,
Compare with a predetermined value Te. If Te has not yet passed, the process proceeds to step # 306 to perform the shake correction only with the shake information from the area sensor 118, the value of the B register is stored in the A register as it is, and the process proceeds to step # 309. On the other hand, if the predetermined time Te has already passed in step # 305, the process proceeds to step # 307 to transfer the A / D conversion value of the shake sensor output to the A register, and then in the next step # 308, The value of the A register and the value of the B register corresponding to the shake information output from the area sensor 118 are added, and the result is reset to the A register.

Here, the interrupt processing operation of the second sampling timer 109 will be described with reference to the flowchart of FIG.

The second sampling timer 109 temporarily stops the main camera sequence operation every time a predetermined time T2 (> T1) elapses after the timer is started in step # 213 of FIG. Step # 4 of 4
In 01, the value of the second sampling timer 109 is reset, and in the next step # 402, the area sensor 118
Stop accumulating. Then, in the next step # 403, the accumulated charge amount is transferred all at once to the sensor memory unit, and after this transfer is completed, in step # 404 the image storage of the sensor is performed from the beginning in preparation for the next image data acquisition. Start.

At the next step # 405, the image data captured by the area sensor 118 and the field memory 119 are stored.
A known correlation calculation with the image data at the time of the previous sampling stored in is performed, and the calculated amount of movement of the image within the sampling interval T2 is set in the S register.

Therefore, as shown in FIG. 7, the area sensor 118 detects the amount of image blur caused by the shake of the camera body.

In FIG. 7, the area information at the time ta and the area information at the time tb differ depending on the shake of the camera body. Therefore, for example, for the shake in the x direction of FIG. From the correlation amount of each j-th row of the information of tb, it is detected how much image blur has occurred. Similarly, for shake in the y direction, how much image shake has occurred is detected from the amount of correlation between the i columns of the information at times ta and tb.

Here, the value of the S register is the area sensor 1 when the sampling time interval (T2) is set.
Since it represents the amount of movement of the subject image in 18, the zoom position of the photographing optical system is set to the internal Z register via the focal length detection circuit (not shown) in the next step # 406, and in step # 407. After setting the focus position of the photographing optical system in the internal F register through a focus position detection circuit (not shown), in step # 408,
From the image movement amount value S, the zoom position value Z, and the focus position value F, the function r (actually S, Z, F
ROM table according to the parameters of the control circuit 101
The moving angle amount R from the previous sampling timing is obtained according to (internal). Further, in step # 409,
By dividing the value of R by the sampling time interval T2,
The relative movement speed is obtained, and the result is set in the V register. In the final step, step # 410, the value of each pixel data detected at this sampling timing is stored in the field memory 119 to be used as reference data at the next sampling timing, and all pixel data is stored in the field memory. When the storage is finished, the interrupt operation by the second sampling timer 109 is finished.

Again the first sampling timer 108 of FIG.
Return to the description of the interrupt processing by. After setting the shake amount to be corrected in the A register, steps # 309 and # 310
Then, similarly to steps # 407 and # 408 of FIG. 4, the zoom position value is set in the Z register and the focus position value is set in the F register. Then, in the subsequent step # 311, the correction system drive amount D is obtained according to a predetermined function d (A, Z, F) based on the value of the A register in which the shake amount is set and the values of the Z and F registers, and the photographing is performed. A target correction amount corresponding to each sensitivity of the optical system is calculated.

Further, in the next step # 312, the absolute position of the correction lens 113 at the present time detected by the correction system position detection circuit 114 of FIG.
02, and the result is set in the internal C register. Then, in the next step # 313, the difference between the target drive amount D of the shake correction system and the current position amount C of the correction lens 113 is set again in the D register, and in the subsequent step # 314, this D Predetermined constant L for the register value
PG (to set the feedback gain of the entire correction system) is multiplied, and the result is reset to the A register.

In the next step # 315, a phase compensation operation is performed on the value of the A register in order to secure the stability of the entire feedback system, and in the subsequent step # 316, the operation result is again stored in the A register. Set. Finally, in step # 317, the value of this A register is set to D /
Transfer to the A converter 103. As a result, the shake correction system drive circuit 111 causes the correction lens 113 to
Will drive.

(Second Embodiment) In the above first embodiment, as shown in FIG. 7, the area sensor 11 of FIG.
The image shake amount is calculated with reference to the data of all pixels of the image pickup device 8. However, if all the pixels are referred to, there is a problem that the calculation processing of the image blur amount takes much time and the phase delay of the blur correction operation becomes large.

Therefore, in the second embodiment of the present invention,
An example of a method of calculating the image blur amount using some of the pixels of the area sensor 118 will be described.

The configuration of the control circuit system and the control flow of the camera operation will be described with reference to FIG. 1 in the first embodiment.
Since it is the same as FIG. 4, the description thereof is omitted.

In the first embodiment described above, after the time counting operation of the second sampling timer 109 is started in step # 213 of FIG.
The amount of shake of the subject on the image plane is calculated from the image data taken in by the area sensor 118 by executing the timer interrupt process shown in (1). However, in the second embodiment of the present invention, the calculation of this shake amount calculation is performed. Instead of using the image data of all the pixels, the shake is calculated using the information of the sensor group in the q-th row and the p-th column that intersect at the center of the area sensor as shown in FIG.

In FIG. 8, the image data at time ta and the image data at time tb differ depending on the shake of the camera body.
The amount of image blurring is detected from the amount of correlation between the information at the times ta and tb in the row. Similarly, with respect to the shake in the y direction, the times ta and t in the central p column in the y direction are
The amount of image blurring is detected from the amount of correlation between pieces of information in b.

Signal Sq from the qth row at time ta
Signals Sq 'from the same portion (stored in the field memory 119) and time tb after a predetermined time T2 has passed are Q images {q1, q2, ..., qN} and Q'images {q1 respectively.
, Q2 ', ..., qN'}, and N image signals, Q image,
The correlation amount M (k) of the Q ′ image is

[Formula 1] Is defined (however, −N / 2 ≦ k ≦ N / 2).

According to the above equation, the correlation amount M (k) is used to calculate the coincidence between the Q image and the Q'image while changing the phase.
K that minimizes the correlation amount M (k) corresponds to the shake amount on the image plane. This value of k is calculated in step # 405 of FIG.
The image blur amount calculation result is set in the S register, and the subsequent calculation process is started.

According to each of the above-described embodiments, in a camera (system) equipped with a vibration isolation device that uses both a mechanical sensor and an image sensor as means for detecting shake, the shutter travel and the mirror accompanying the exposure operation of the camera. It is possible to avoid abnormal response of the mechanical sensor and the correction optical system due to the impact of up, and to perform the image stabilization control based on the actual shake based on the shake data detected by the image sensor. Anti-vibration system can be realized.

In the above embodiment, the shake sensor 10
4, 106 and the filter circuits 105 and 107 correspond to the first shake detecting means of the present invention, and the area sensor 118, the field memory 119 and the motion vector detecting circuit 120 correspond to the second shake detecting means of the present invention. Shake correction system drive circuit 111, correction lens 113, correction system position detection circuit 11
Reference numeral 4 corresponds to the shake correction means of the present invention.

(Modification) In the first embodiment, the shutter during the exposure operation is performed by performing the shake correction using only the signal of the image sensor until a predetermined time elapses after the exposure operation of the camera is started. Avoid abnormal response of mechanical sensor and correction optical system due to impact of members,
Moreover, the method for performing the image stabilization control based on the actual shake based on the shake data detected by the image sensor is explained, and the area sensor for photometry is used as the image sensor, but of course, for the distance measurement. Or area sensor or line sensor for focus detection,
Alternatively, an independent sensor for shake detection may be used. Further, the mechanical sensor may be an angular velocity meter, an angular accelerometer, an accelerometer or the like as long as the shake can be detected.

Further, the second embodiment described above describes a method for smoothly performing the anti-vibration operation when realizing the anti-vibration system described in the first embodiment. In this embodiment, the intersecting line portions (pixel rows in the two-dimensional direction) at the center of the area sensor are used, but other methods such as using the area at the center of the sensor are also available. Good.

[0061]

As described above, according to the present invention,
It is possible to provide an anti-vibration system capable of improving anti-vibration accuracy by always performing anti-vibration control based on actual shake.

[Brief description of drawings]

FIG. 1 is a block diagram showing a circuit configuration of a main part of a camera system including an image stabilization device according to each embodiment of the present invention.

FIG. 2 is a flowchart showing a series of operations of the camera of the first embodiment of the present invention.

FIG. 3 is a flowchart showing a first sampling timer interrupt process in the first embodiment of the invention.

FIG. 4 is a flowchart showing a second sampling timer interrupt process in the first embodiment of the invention.

5 is a diagram showing a specific configuration of a shake sensor and a filter circuit according to the mechanical configuration of FIG.

FIG. 6 is an exploded perspective view showing the configuration of the correction optical system in FIG.

FIG. 7 is a diagram illustrating a method of detecting an image blur amount from an area sensor according to the first embodiment of the present invention.

FIG. 8 is a diagram for explaining a method of detecting an image blur amount from an area sensor in the second embodiment of the present invention.

[Explanation of symbols]

101 control circuit 104, 106 shake sensor 105, 107 filter circuit 108 First sampling timer 109 2nd sampling timer 110 Third timer 111 Shake correction system drive circuit 113 Image stabilization lens 118 area sensor 119 field memory 120 Motion vector detection circuit

Claims (7)

[Claims] 1. A first shake detecting means for detecting shake of the system, a second shake detecting means for detecting shake by a method different from the first shake detecting means, and the first shake detecting means. And a shake correcting means for performing shake correction based on the output of the second shake detecting means, and the shake based on only the output of the second shake detecting means until a predetermined time elapses after the exposure operation is started. Anti-vibration system characterized by making corrections. 2. The first shake detecting means detects a shake of the system from an angular velocity around a predetermined axis using a vibrating gyro, and the second shake detecting means is an image sensor through an optical system. The image stabilization system according to claim 1, wherein shake is detected from a correlation amount between image data formed at different times at different times. 3. The second shake detecting means detects a shake from a correlation amount of image data formed on an image sensor through an optical system at different times, and the shake is calculated by calculating the image. The image stabilization system according to claim 1, wherein a part of pixels of the sensor is used. 4. The part of the pixels of the image sensor is a pixel row in the two-dimensional direction intersecting the center of the pixels of the image sensor. Anti-vibration system. 5. The image stabilization system according to claim 3, wherein a part of the pixels of the image sensor is a pixel in a central portion of the pixels of the image sensor. 6. The predetermined time period is a time period during which an output of the first shake detection unit responds abnormally due to an impact of an exposure member during an exposure operation. The vibration isolation system according to any one of 1. 7. The image stabilizing system according to claim 6, wherein the exposure member is a shutter member.