JP3584270B2 - Shutter device - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to a camera shutter device having a function of double-blocking an exposure opening during non-photographing.
[0002]
[Prior art]
For the purpose of improving the light-shielding property of the exposure opening of the focal plane shutter, there has been proposed a shutter having a double light-shielding function of covering the exposure opening with both the front curtain blade group and the rear curtain blade group during non-shooting. In such a shutter, after the rear curtain blade group is retracted out of the exposure opening from the double light blocking state at the time of non-photographing, exposure is started by traveling the front curtain blade group, and exposure is completed by traveling the rear curtain. . Then, a charging operation is performed to store the energy required for running the blades for the next shooting in the spring, and the front curtain blades cover the exposed openings, and the rear curtain blades are exposed at the exposed openings. Operate to a position that covers part or all.
[0003]
Among the series of operations described above, some proposals have been made on the timing of performing the operation of retreating the rear curtain blade group outside the exposure opening (double light blocking release) before the start of exposure. For example, as a first conventional example, Japanese Patent Application Laid-Open No. 2-97927 proposes a shutter in which double release is released when a release button is half-pressed by a photographer, and double release is performed when the release button is returned. Have been. According to this method, after the photographer half-presses the release button to release the double shading, the photographer can immediately start the exposure start operation when the photographer fully presses the release button at a photo opportunity. This has the effect of reducing the time lag at the time of release as compared with the method of releasing the double light blocking after fully pressing the release button.
[0004]
As a second conventional example, Japanese Patent Application Laid-Open No. Hei 3-288835 proposes a method in which a retracting operation of a mirror retracting to the outside of a photographing optical path at the time of exposure and an operation of releasing a double light shielding of a shutter are linked. According to this method, when the release button is half-pressed to release the double light shielding after the release button is released and the button is released as compared with the first conventional example, there is no needless operation to put the double light shielding state again. This has the effect.
[0005]
[Problems to be solved by the invention]
In contrast to the first conventional example, the applicant of the second conventional example may distract the photographer due to the blade running sound, or drive only the rear blade other than during normal shooting. However, it has been pointed out that there is a possibility of repeated damages.
[0006]
Further, the second conventional example has the following problems. Many cameras with double shading are expensive, and this class of cameras has a mirror lockup mechanism that locks the mirror in the raised position before pressing the release button to prevent the mechanism from swinging due to the mirror. Often attached. In such a camera, when a shutter having a double light shielding function as in the second conventional example is mounted, the double light shielding is released when the mirror is locked up. However, the effect of double shading can be exerted only when the mirror is up, and the method of the second conventional example is not rational.
[0007]
Therefore, in order to solve these problems, the double light blocking release is performed in a manner not linked to the mirror-up mechanism between the time when the release button is fully pressed and the time when the front curtain runs. Considering the camera shake due to the cancellation of the double light blocking, the earlier the timing of canceling the double light blocking, the better. In order to prevent light leakage from the blades, the timing of releasing the double light blocking is as late as possible, and it is better to set the timing immediately before the front curtain travel. As described above, there is room for improvement in that the double light-blocking release has advantages and disadvantages at any timing.
[0008]
SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to obtain an optimal double light shielding mechanism by making the timing of releasing double light shielding variable.
[0009]
[Means for Solving the Problems]
In order to achieve this object, the shutter device according to the present invention includes a light-shielding unit including a plurality of light-shielding blade groups, and before the exposure operation, the exposure opening is double-shielded by the light-shielding unit, and the exposure operation is instructed. A shutter device for starting the opening and closing operation of the exposure opening by the light shielding means after releasing the double light shielding state by the light shielding means, comprising a control means for controlling a timing of releasing the double light shielding state; The timing is made variable.
[0010]
[Action]
In the shutter device having the above configuration, an optimal double light shielding mechanism can be obtained by making the timing of releasing double light shielding variable. When the luminance of the subject is high, the shutter speed is generally high, the influence of the mechanism shake is reduced, and the possibility of light leakage from the shutter blades is increased. When the subject brightness is low, the shutter speed is slowed, the effect of the mechanism shake becomes large, and the possibility of light leakage from the shutter blades is low. Therefore, it is better to make the timing of canceling the double light shielding earlier. As described above, by optimally changing the timing of canceling the double shading according to the luminance of the subject, an optimum double shading function can be obtained.
[0011]
【Example】
Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, the configuration of the embodiment of the present invention will be described. The following description of the configuration is common to the first embodiment and the second embodiment described later.
[0012]
FIG. 1 is a side sectional view of a camera on which a shutter device of the present invention is mounted. At the time of non-shooting, light passing through the lens 102 is reflected by a mirror 104 in the camera body, is diffused on a frosted glass screen 105, and reaches a finder 106 and a photometry unit 107 after passing through a pentaprism. At the time of photographing, the mirror 104 rises due to the engagement of the mirror biasing spring (not shown) being released by the solenoid 112 (not shown), and the light passing through the lens 102 reaches the shutter unit 103.
[0013]
FIG. 2 is a block diagram showing a control system of the camera. The power switch unit 113 of the camera body is connected to the CPU 108. The power switch unit 113 also includes a circuit for detecting the ON / OFF state of the switch. A release switch unit 114 is also connected to the CPU 108, and the release switch unit 114 includes a circuit for detecting the OFF, half-press, and full-press states of the release button. The photometry unit 107 is a light quantity detection device such as an SPD (Silicon Photo Diode), and is connected to the CPU 108 via a photometry circuit 111, and a memory 109 for storing photometry information here is also connected to the CPU 108. The CPU 108 is also connected to a control circuit 110. The control circuit 110 controls the front curtain electromagnet 25, the rear curtain electromagnet 28, the solenoid 24 for canceling double light shielding, and the solenoid 112 for raising the mirror based on an instruction from the CPU 108. Control.
[0014]
The mechanical unit of the shutter unit 103 (FIG. 1) is formed in three layers by a cover plate 3, a substrate 1 and a magnet substrate 2. Hereinafter, the layer between the substrate 1 and the magnet substrate 2 is referred to as a lower layer, and the upper part of the substrate 2 is referred to as an upper layer. FIG. 3 shows the state of the lower layer immediately after the charging is completed and before the double light blocking is released. The configuration of the shutter blade drive mechanism will be described with reference to FIG. In FIG. 3, the front curtain driving lever 4 is rotatably attached to the substrate 1 and is urged clockwise by a front curtain driving lever urging spring 5. The front-curtain drive lever 4 is provided with a roller 4a that comes into contact with the roller 16a of the charge lever 16 and a pin 4b that is rotatably fitted to the front-curtain drive arm 32 (see FIG. 4). A front curtain key 6 that locks the front curtain drive lever 4 against the urging spring 5 until just before the front curtain travels is rotatably attached to the substrate 1, and is rotated counterclockwise by the front curtain key spring 7. Has been energized. Further, the front curtain key 6 is provided with a protruding portion for coming into contact with a front curtain armature lever 26 (see FIG. 5) above the magnet substrate 2.
[0015]
The second rear curtain drive lever 12 (FIG. 3) is rotatably attached to the substrate 1 and is urged counterclockwise by the second rear curtain drive lever urging spring 13. A pin 12a is attached to the second rear curtain drive lever 12, and the pin 12a is rotatably fitted to the rear curtain drive arm 35 (see FIG. 4). The first rear curtain drive lever 8 is mounted on and coaxial with the second rear curtain drive lever 12 so as to be rotatable relative to the substrate 1 and the second rear curtain drive lever 12. It is urged clockwise by a curtain drive lever urging spring 9. The first rear curtain drive lever 8 is provided with a drive pin 8b for driving the second rear curtain drive lever 12 during rear curtain travel. A second rear curtain key 14 that locks the second rear curtain drive lever 12 against the biasing spring 13 until just before the double light blocking is released is rotatably attached to the substrate 1, and is connected to the second rear curtain. It is biased clockwise by the key spring 15. A first rear curtain key 10 that locks the first rear curtain drive lever 8 against the urging spring 9 until just before the rear curtain travel is rotatably attached to the substrate 1. It is urged clockwise by the curtain key spring 11. Further, the first rear curtain key 10 is provided with a protruding portion for coming into contact with the rear curtain armature lever 29 (see FIG. 5) on the magnet substrate 2.
[0016]
A charge lever 16 for returning to the double light-shielded state after the rear curtain travels is rotatably attached to the substrate 1 and is urged counterclockwise by a charge lever urging spring 17. Rollers 16a and 16b are attached to the charge lever 16 for contacting and driving the front curtain drive lever roller 4a and the first rear curtain drive lever roller 8a, respectively, at the time of the returning operation to the double light blocking state. Further, a pin 16c for driving the armature pressing lever 18 is attached.
[0017]
The armature pressing lever 18 is for mechanically pressing the first-curtain armature lever 26 and the second-curtain armature lever 29 against the electromagnets 25 and 28 in a double-shielded state (see FIG. 5), and has an armature pressing lever. It is urged clockwise by an urging spring 19. The armature pressing lever key 20 is rotatably attached to the back side of the magnet substrate 2 in FIG. 5, and is urged clockwise by the armature pressing lever key spring 21 in FIG. The armature holding lever 18 is locked against the biasing spring 19 until the heavy light shielding is released. The release lever 22 is rotatably attached to the substrate 1 and is urged counterclockwise by a release lever urging spring 23. The release lever 22 is configured to abut the armature holding lever key 20, the second rear curtain key 14, and the movable portion of the solenoid 24, respectively. The solenoid 24 is fixed to the substrate 1, and when a current flows, the movable portion is displaced downward in FIG.
[0018]
In FIG. 5, the leading curtain electromagnet 25 and the trailing curtain electromagnet 28 are fixed to the magnet substrate 2. The magnet substrate 2 is provided with a hole through which the protruding portions of the front curtain key 6 and the first rear curtain key 10 are provided. The front curtain armature lever 26 is rotatably attached to the magnet substrate 2, is urged clockwise by an urging spring 27, and comes into contact with the extension of the front curtain key 6. The rear curtain armature lever 29 is rotatably attached to the magnet substrate 2, is urged counterclockwise by an urging spring 30, and comes into contact with the extension of the first rear curtain key 10. Further, the front curtain armature lever 26 is configured to abut the armature pressing lever 18 and the rear curtain armature lever 29 during the double light blocking state return operation and the double light blocking state.
[0019]
In FIG. 6, 31a, 31b, and 31c are front curtain blades. The front curtain driving arm 32 and the front curtain driven arm 33 are rotatably mounted between the substrate 1 and the cover plate 3, and hold the blades 31 a, 31 b, and 31 c in a vertical direction by using a known link mechanism. Exercise. The first-curtain drive arm 32 is driven by the first-curtain drive lever 4 described above.
[0020]
In FIG. 7, reference numerals 34a, 34b, and 34c denote trailing blades. The rear curtain drive arm 35 and the rear curtain driven arm 36 are rotatably mounted between the substrate 1 and the cover plate 3, and hold the blades 34 a, 34 b, and 34 c in a vertical direction by using a known link mechanism. Exercise. The rear curtain drive arm 35 is driven by the second rear curtain drive lever 12 described above.
[0021]
Next, as a first embodiment, a method of simply changing the timing of canceling the double light shielding to two stages before or after the mirror up will be described.
[0022]
3 to 5 are front views showing a state immediately after charging is completed and before double light shielding is released. FIGS. 6, 8, and 9 are front views showing a state immediately after the release of the double shade and before the front curtain travel. FIGS. 7, 10, and 11 show states immediately after the rear curtain travel and before charging. It is the front view which showed. FIG. 12 is a flowchart showing the operation of the first embodiment, and the operation of the first embodiment of the camera equipped with the shutter device of the present invention will be described with reference to FIGS. 2 to 11. . The operation starts when the power switch 113 of the camera body 101 is turned on.
[0023]
If the CPU 108 recognizes in step S201 that the release switch 114 has been half-pressed, the process proceeds to step S202. If not half-pressed, the process proceeds to step S212.
[0024]
In step S202, the CPU 108 causes the photometry circuit 111 to start photometry. The photometric value (subject luminance) detected by the photometric unit 107 is provided to the CPU 108 via the photometric circuit 111 and stored in the memory 109. This operation is repeated while the release switch 114 is half-pressed, and the information stored in the memory 109 is updated one by one.
[0025]
In step S203, when the release switch 114 is fully pressed, the CPU 108 calculates the shutter speed and the aperture value using the latest subject luminance information stored in the memory 109, and releases the double light blocking of the shutter blade. Decide when to do it. On the other hand, if the release switch 114 is not fully pressed, the process returns to step S201.
[0026]
If the CPU 108 determines in step S204 that the subject brightness is higher than a certain reference, the mirror raising operation is performed first in order to delay the timing of canceling the double light shielding as much as possible. In step S205, a mirror raising operation is performed. The CPU 108 operates the mirror raising solenoid 112 to release the lock of the spring biasing the mirror upward, and the mirror 104 is raised by the biasing force of the spring. At this point, the state of the mechanical unit of the shutter unit is the same as in FIGS. 3, 4, and 5 except for the position of the charge lever 16, and the position of the charge lever 16 in FIG. It will be in the same position as.
[0027]
In step S206, a double light blocking release operation is performed. The CPU 108 causes the control circuit 110 to start energizing the first-curtain electromagnet 25 and the second-curtain electromagnet 28 to bring the first-curtain armature lever 26 and the second-curtain armature lever 29 into a suction state. The attraction force of this electromagnet is greater than the urging force of the front curtain armature lever urging spring 27 and the rear curtain armature lever urging spring 30.
[0028]
Further, the CPU 108 causes the control circuit 110 to drive the movable portion of the solenoid 24 for releasing double light shielding downward as shown in FIG. The release lever 22 which is in contact with the movable part of the solenoid 24 rotates clockwise against the urging spring 23, and rotates the armature holding lever key 20 counterclockwise against the urging spring 21. The armature holding lever 18 is unlocked, and the armature holding lever 18 rotates clockwise by the urging force of the urging spring 19 until it comes into contact with the pin 16c of the charge lever 16. As a result, the front curtain armature lever 26 and the rear curtain armature lever 29 are held against the urging springs 27 and 30 only by the attraction force of the electromagnet as shown in FIG.
[0029]
In FIG. 9, the second rear curtain key 14 is rotated counterclockwise against the urging spring 15 with the clockwise rotation of the release lever 22. The stop is released, and the second rear curtain drive lever 12 rotates counterclockwise by the urging force of the urging spring 13 until it comes into contact with the pin 8 b of the first rear curtain drive lever 8. As a result, as shown in FIG. 6, the rear curtain driving arm 35 and the rear curtain driven arm 36 rotate counterclockwise, and accordingly, the rear curtain blades 34a, 34b, and 34c are kept above the exposed opening while keeping the horizontal state. Go to As a result, the double light blocking state is released, and the exposure opening is blocked only by the leading blades 31a, 31b, and 31c. FIGS. 6, 8, and 9 show a state at the time when the above operation is completed.
[0030]
In step S204, when the CPU 108 determines that the subject luminance is darker than a certain reference value, the CPU 108 first performs the double light blocking release operation. In step S207, the double light blocking release solenoid 24 is driven to perform the double light blocking release operation. The details of the double light blocking release operation are the same as those in the above-described step S206 in which the mirror is raised first. In step S208, the mirror raising operation is performed after the rear curtain blades 34a, 34b, and 34c have completed raising. The details of the mirror raising operation are exactly the same as those in the above-described step S205 in which the mirror raising is performed first. However, in this case, it is desirable that a time lag equivalent to the time required for canceling the double light shielding be provided between the completion of the mirror raising and the start of the front curtain driving described later. This is because the advantage of making the double light-blocking timing earlier when the subject has low brightness is that exposure can be started after the mechanism shake due to the double light-blocking release operation has subsided. This is because the effect of the mechanism shake due to the elevation of the mirror appears in the captured image, and the advantage of the present invention is diminished.
[0031]
In step S209, an exposure start operation by running the front curtain blades is performed. The CPU 108 causes the control circuit 110 to stop energizing the front curtain electromagnet 25. Then, in FIG. 10, the front curtain armature lever 26 is released from the attraction by the front curtain electromagnet 25, is rotated clockwise by the urging force of the urging spring 27, and is brought into contact with the front curtain key 6 at the front curtain key 6. 6 is rotated clockwise against the urging force of the urging spring 7. As a result, the lock between the front curtain key 6 and the front curtain drive lever 4 is released in FIG. 11, and the front curtain drive lever 4 rotates clockwise by the urging force of the urging spring 5. Along with this, in FIG. 7, the front curtain driving arm 32 and the front curtain driven arm 33 rotate clockwise, and the front curtain blades 31a, 31b, and 31c move below the exposure opening while keeping the horizontal state. Then, exposure to the film surface is started.
[0032]
In step S210, an exposure end operation is performed by running the trailing blade. The CPU 108 causes the control circuit 110 to stop energizing the rear curtain electromagnet 28 at a timing corresponding to the previously obtained shutter speed data. Then, in FIG. 10, the rear curtain armature lever 29 is released from being attracted by the rear curtain electromagnet 28, is rotated counterclockwise by the urging force of the urging spring 30, and is brought into contact with the first rear curtain key 10. The first rear curtain key 10 is rotated counterclockwise against the urging force of the urging spring 11. As a result, the locking of the first rear curtain key 10 and the first rear curtain drive lever 8 in FIG. 11 is released, and the first rear curtain drive lever 8 is brought into contact with the pin 8 b by the urging force of the urging spring 9. The second rear curtain drive lever 12 rotates clockwise against the biasing spring 13 of the second rear curtain drive lever 12 together with the second rear curtain drive lever 12. Accordingly, in FIG. 7, the rear curtain driving arm 35 and the rear curtain driven arm 36 rotate clockwise, and the rear curtain blades 34a, 34b, and 34c move downward while keeping the horizontal state, and move to the film surface. Exposure ends. The state where the above operation is completed is shown in FIGS. 7, 10, and 11.
[0033]
In step S211, a charging operation is performed for the next shooting. By a motor and a mechanism (not shown), the charge lever 16 rotates clockwise to the position shown in FIG. Along with this, the front curtain drive lever 4 which is in contact with the charge lever roller 16a and the front curtain drive lever roller 4a rotates counterclockwise against the biasing spring 5 and is engaged by the front curtain key 6. Is stopped. Also, the first rear curtain drive lever 8, which is in contact with the charge lever roller 16 b and the first rear curtain drive lever roller 8 a, rotates counterclockwise against the biasing spring 9. It rotates and is locked by the first rear curtain key 10.
[0034]
Further, with the rotation of the charge lever 16, the armature holding lever 18 rotates counterclockwise against the biasing spring 19 by the pin 16 c fixed to the charge lever, and is locked by the armature holding lever key 20. Is done. As a result, in FIG. 5, the front curtain armature lever 26 rotates counterclockwise against the biasing spring 27 by the armature pressing lever 18 and is pressed against the front curtain electromagnet 25. The rear curtain armature lever 29 that is in contact with the front curtain armature lever 26 also rotates clockwise against the urging spring 30 and is pressed against the rear curtain electromagnet 28. FIGS. 3 to 5 show a state in which the above operation is completed. Immediately after this state, the charge lever 16 rotates counterclockwise by the urging force of the urging spring 17, and returns to the position of the charge lever in FIG.
[0035]
If the power switch is turned off in step S212, all the operations are terminated, and if not, the process waits again until the release switch is half-pressed again.
[0036]
Next, as a second embodiment, the timing of canceling the double shading is finely set in multiple stages according to the numerical value of the subject luminance information, and the criteria for determining the timing of canceling the double shading are the same as in the first embodiment. Instead of using the subject brightness as it is, a method of using a shutter speed calculated from the subject brightness will be described.
[0037]
FIG. 13 is a flowchart showing the operation of the second embodiment, which will be described with reference to FIGS. Note that the present invention also includes a method of setting the timing of canceling the double shading to two steps and using the shutter speed as a determination criterion, and a method of setting the timing of canceling the double shading to multiple steps and setting the determination criterion to the subject brightness. .
[0038]
In step S301, if the CPU 108 recognizes that the release switch 114 has been half-pressed, the process proceeds to step S302. If it has not been half-pressed, the process proceeds to step S312.
[0039]
In step S302, the CPU 108 causes the photometry circuit 111 to start photometry. The photometric value (subject luminance) detected by the photometric unit 107 is provided to the CPU 108 via the photometric circuit 111 and stored in the memory 109.
[0040]
In step S303, the CPU 108 determines the shutter speed and the aperture based on the subject luminance stored in the memory 109 in step S302. Further, based on the value of the shutter speed, the CPU 108 determines a time T [second] from when the mirror is raised to when the double light shielding is released and a time T ′ [second] from when the double light shielding is released to when the front curtain runs. I do. However, there is the following relationship between T and T ′.
[0041]
T + T '= constant
[0042]
When the shutter speed is high, the possibility of light leakage from the shutter blades is high, and the influence of the mechanism shake due to the double light blocking release operation is small, so that T is made longer and T 'is made shorter. When the shutter speed is low, the possibility of light leakage from the shutter blades is low, and the effect of the mechanism shake due to the double light blocking release operation is large, so that T is shortened and T 'is lengthened. The operations of step S302 and step S303 are repeated while the release switch is half-pressed.
[0043]
If the release switch has been fully pressed in step S304, the process proceeds to step S305 to perform a shooting operation. If the release switch is turned off in step S304, the photometric operation is stopped, and a standby state is established until the power switch is turned off (step S312) or the release switch is half-pressed again (step S301).
[0044]
In step S305, a mirror raising operation is performed. The details of this operation are the same as in step S205 of the first embodiment. In step S306, the CPU 108 waits for T seconds determined in step S303. In step S307, a double light blocking release operation is performed. The details of this operation are the same as in step S206 of the first embodiment. In step S308, the CPU 108 waits for T ′ seconds determined in step S303.
[0045]
In step S309, an exposure start operation by running the front curtain blades is performed. Details of this operation are the same as in step S209 of the first embodiment. In step S310, an exposure end operation is performed by running the trailing blade. The details of this operation are the same as in step S210 of the first embodiment. In step S311, a charging operation is performed for the next shooting. The details of this operation are the same as in step S211 of the first embodiment. If the power switch is turned off in step S312, all the operations are terminated. If the release switch is again half-pressed (step S301), the above series of operations is repeated.
[0046]
【The invention's effect】
As described above, according to the shutter device of the present invention, the control means for controlling the timing of releasing the double light blocking state changes the timing of the double light blocking release, so that an optimal double light blocking mechanism is obtained. It becomes possible.
[Brief description of the drawings]
FIG. 1 is a side view of a camera on which a shutter device of the present invention is mounted.
FIG. 2 is a diagram showing a control system of a camera on which a shutter device of the present invention is mounted.
FIG. 3 is a front view of a lower layer portion of a shutter mechanism immediately after charging is completed.
FIG. 4 is a front view of a shutter blade immediately after charging is completed.
FIG. 5 is a front view of the upper layer of the shutter mechanism immediately after charging is completed.
FIG. 6 is a front view of the shutter blade immediately after double light blocking is released.
FIG. 7 is a front view of the shutter blade immediately after the rear curtain travels.
FIG. 8 is a front view of the upper layer of the shutter mechanism immediately after the double light blocking is released.
FIG. 9 is a front view of a lower layer portion of the shutter mechanism immediately after double light blocking is released.
FIG. 10 is a front view of the upper layer of the shutter mechanism immediately after the rear curtain travels.
FIG. 11 is a front view of a lower portion of the shutter mechanism immediately after the rear curtain travels.
FIG. 12 is a flowchart showing an operation of the first embodiment of the camera equipped with the shutter device of the present invention.
FIG. 13 is a flowchart showing the operation of a second embodiment of the camera equipped with the shutter device of the present invention.
[Explanation of symbols]
1 substrate
2 Magnet substrate
3 Cover plate
4 Front curtain drive lever
About 4a
4b pin
5 Front curtain drive lever biasing spring
6 First curtain key
7 Front curtain key urging spring
8 1st rear curtain drive lever
8a Roller
8b pin
9 1st rear curtain drive lever biasing spring
10 First trailing key
11 1st rear curtain key biasing spring
12 Second rear curtain drive lever
12a pin
13 Second rear curtain drive lever biasing spring
14 Second trail key
15 Second trailing key biasing spring
16 Charge lever
16a, 16b roller
16c pin
17 Charge lever biasing spring
18 Armature holding lever
19 Armature holding lever biasing spring
20 Armature holding lever key
21 Armature holding lever key biasing spring
22 Release lever
23 Release lever biasing spring
24 Solenoid for Double Shading Cancellation
25 Front curtain electromagnet
26 First curtain armature lever
27 First curtain armature lever biasing spring
28 Rear curtain electromagnet
29 Rear curtain armature lever
30 Rear curtain armature lever biasing spring
31a, 31b, 31c First curtain blade
32 Front curtain drive arm
33 Front curtain driven arm
34a, 34b, 34c Trailing blade
35 Rear curtain drive arm
36 Rear curtain driven arm
101 Camera Body
102 lens
103 Shutter unit
104 mirror
105 screen
106 Finder
107 Metering unit
108 CPU
109 memory
110 control circuit
111 photometric circuit
112 Mirror raising solenoid
113 Power switch section
114 Release switch

Claims (4)

A light-shielding means comprising a plurality of light-shielding blade groups is provided.Before the exposure operation, the exposure opening is double-shielded by the light-shielding means, and after the exposure operation is instructed, the double light-shielding state by the light-shielding means is released. A shutter device for starting the opening and closing operation of the exposure opening by the light shielding means;
Control means for controlling the timing of releasing the double light blocking state,
The control device is capable of changing the release timing. Further comprising a luminance detecting means for detecting the luminance of the subject,
The shutter device according to claim 1, wherein the control unit controls the release timing according to the luminance. Further comprising a second time detecting means for detecting a shutter time controlled by the light shielding means,
The shutter device according to claim 1, wherein the control unit controls the release timing according to the shutter time. The control unit is configured to control the exposure by the light shielding unit after the movable mirror retracts from the imaging optical path to the outside of the imaging optical path for a first period from the completion of the retraction to the release timing and after the release of the double light shielding state is completed. 2. The shutter device according to claim 1, wherein a control is performed so that a total period including the second period up to the start time of the opening and closing operation of the opening is constant.

Images