Imaging device

Abstract

To provide a shutter unit that can achieve both increase in a speed of continuous shooting and reduction in a size.SOLUTION: A shutter unit (1000) has: a bottom board (910) that is formed with an opening (910a); at least one blade member (800); a driving member (500) that is rotatably and pivotally supported on the bottom board, and drives the blade member from a standby position to a travel completion position by using urging force of an urging member (511) during photographing; a brake member (630) that is in contact with the driving member and decelerates the driving member; and a charge member (317) that actuates the driving member from the travel completion position to a set position against the urging force of the urging member and subsequently actuates the driving member to the standby position, and actuates the brake member from the travel completion position to the standby position while actuating the driving member from the set position to the standby position.SELECTED DRAWING: Figure 3(b)

Description

[Technical Field]

[0001] The present invention relates to a shutter unit and an imaging device. [Background technology]

[0002] In recent years, in imaging devices such as digital single-lens reflex cameras and mirrorless cameras, there has been a demand for faster continuous shooting speeds (higher frame rates) and smaller imaging devices for easier portability in order to capture moving subjects more reliably. Conventionally, shutter units used in imaging devices have been known to have a brake function that slows down the blades just before they complete their travel, in order to reduce the risk of blade damage and dust generation by absorbing the impact of the blades as they travel.

[0003] Patent Document 1 discloses a focal plane shutter (shutter unit) that can move a braking member from a travel completion position to a standby position by a cam gear that operates a blade driving member. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-59331 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the shutter unit disclosed in Patent Document 1, the brake member is moved from the travel completion position to the standby position while the blade drive member is operating. Therefore, the overlapping of the blade drive member and the brake member operation increases the peak load during operation, and the motor rotation speed decreases, resulting in a decrease in the continuous shooting speed. In order to increase the continuous shooting speed, a larger motor is required, which results in an increase in the size of the shutter unit.

[0006] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a shutter unit and an imaging device that can achieve both high speed continuous shooting and compact size. [Means for solving the problem]

[0007] As one aspect of the present invention Imaging device the camera includes a base plate having an opening formed therein, at least one blade member, a drive member rotatably supported on the base plate and configured to drive the blade member from a standby position to a travel completion position by the biasing force of a biasing member during photography, a braking member that contacts the drive member and decelerates the drive member, a charging member that moves the drive member from the travel completion position to a set position against the biasing force of the biasing member and then to the standby position, and that moves the braking member from the travel completion position to the standby position while the drive member is moving from the set position to the standby position, a motor that supplies a driving force to the charging member, rotational speed detection means that detects the rotational speed of the motor, and a control unit, and the control unit controls the motor so that the rotational speed of the motor detected by the rotational speed detection means becomes a predetermined rotational speed while the drive member is moving from the set position to the standby position. By doing so, the rotation speed of the charge member is made constant, and the speed at which the contact between the drive member and the charge member is released is made constant. .

[0008] Other objects and features of the present invention will be described in the following embodiments. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a shutter unit and an imaging device that can achieve both high speed continuous shooting and compact size. [Brief explanation of the drawings]

[0010] [Figure 1] 1A and 1B are a central cross-sectional view and a block diagram showing an electrical configuration of an imaging system according to an embodiment of the present invention. [Figure 2] FIG. 2 is a perspective view of a focal plane shutter according to the present embodiment. [Figure 3(a)]FIG. 2 is an exploded perspective view of the focal plane shutter according to the embodiment. [Figure 3(b)] FIG. 2 is an exploded perspective view of the focal plane shutter according to the embodiment. [Figure 4(a)] FIG. 2 is a perspective view of a charging system component group and a base plate in the present embodiment. [Figure 4(b)] FIG. 2 is a perspective view of a charging system component group and a base plate in the present embodiment. [Figure 5] FIG. 2 is an exploded perspective view of the brake unit according to the embodiment. [Figure 6] FIG. 2 is an exploded perspective view of the first driving lever unit according to the embodiment. [Figure 7] FIG. 2 is an exploded perspective view of the rear drive lever unit according to the embodiment. [Figure 8] FIG. 2 is a front view of the focal plane shutter with the MG base plate unit removed in this embodiment. [Figure 9] 1A and 1B are front and rear views in a set phase showing the relationship between the drive lever unit and the cam gear, the first locking lever, the second locking lever, the one-way lever, and the reverse charge lever in this embodiment. [Figure 10] 10A and 10B are front and rear views of the one-way lever when charging by the intermediate cam gear is completed in this embodiment. [Figure 11] 10A and 10B are front and rear views of the state when charging of the leading blade lever by the reverse charge lever is completed in the embodiment. [Figure 12(a)] 3 is a cam diagram showing the movement of each component and the signal state when the motor rotates forward in this embodiment. FIG. [Figure 12(b)] 3 is a cam diagram showing the movement of each component and the signal state when the motor rotates forward in this embodiment. FIG. [Figure 13] FIG. 2 is a side view of the focal plane shutter of the embodiment as viewed from the charge system component group side. [Figure 14] 1A and 1B are a plan view and a cross-sectional view showing a normally open state in this embodiment. [Figure 15]10 is a plan view showing a state in which the cam of the intermediate cam gear starts to contact the actuated portion of the second locking lever in this embodiment. FIG. [Figure 16] FIG. 10 is a plan view showing a state in which the imaging standby phase has been reached in this embodiment. [Figure 17] 10 is a plan view showing a state in which an actuated portion of a first locking lever abuts against a cam of a leading curtain charge cam gear in the embodiment. FIG. [Figure 18] 10 is a plan view showing a state in which the locking of the leading blade lever by the first locking lever is released in this embodiment. FIG. [Figure 19] 10A and 10B are plan and rear views showing a state in which the cam of the leading curtain charge cam gear starts to abut against the cam follower of the leading brake lever in the embodiment. [Figure 20] A plan view showing the state in which the leading blade lever in this embodiment is starting to abut against the second locking lever, and a cross-sectional view showing the state in which the cam of the intermediate cam gear is starting to abut against the cam follower portion of the one-way lever. [Figure 21] 10 is a plan view showing a state in which the front shutter curtain has completed transition from an overlapping state to an expanded state in this embodiment. FIG. [Figure 22] 10 is a plan view showing a state in which the leading driving lever unit and the trailing driving lever unit have reached a set position in this embodiment. FIG. [Figure 23] FIG. 10 is a plan view showing a state in which the camera is stopped in a photographing standby phase in this embodiment. [Figure 24] 10A and 10B are a plan view and a rear view showing a state in which the leading drive lever unit and the leading blade lever have completed traveling in this embodiment. [Figure 25] 10A and 10B are a plan view and a rear view showing a state in which the rear drive lever unit in this embodiment has completed traveling. [Figure 26] 10 is a plan view showing a state in which the cam of the leading curtain charge cam gear operates the operated portion of the first locking lever to release the lock in the embodiment. FIG. [Figure 27] 10A and 10B are a cross-sectional view and a rear view showing a state in which the cam of the leading curtain charge cam gear starts to abut against the cam follower of the leading brake lever in the embodiment. [Figure 28] 10 is a plan view showing a state in which the front brake lever is stopped at the operation standby position and the cam of the rear curtain charge cam gear starts to abut against the roller of the rear drive lever in this embodiment. FIG. [Figure 29] 10A and 10B are a plan view and a cross-sectional view showing a state in which the front driving lever, the front blade lever, and the rear driving lever in this embodiment are in a set position where charging has been completed. [Figure 30] FIG. 2 is a cam diagram showing the movement of each part and the signal state from when the motor is energized in the reverse direction until the normally open state is reached in this embodiment. [Figure 31] 10 is a plan view showing a state in which the second locking lever has moved to a cam bottom of the intermediate cam gear in this embodiment. FIG. [Figure 32] 10A and 10B are a plan view and a cross-sectional view showing a state in which the cam of the intermediate cam gear abuts against the cam follower of the one-way lever and reverse charging has started in this embodiment. [Figure 33] 10A and 10B are a plan view and a cross-sectional view showing a state in which a pushing portion of a reverse charge lever starts to contact a roller of a leading blade lever in the embodiment. [Figure 34] 1A and 1B are a plan view and a cross-sectional view showing a reverse charging completed state in this embodiment. [Figure 35] 10A and 10B are a plan view and a cross-sectional view showing a state in which the roller of the leading blade lever is separated from the pushing portion of the reverse charge lever in the embodiment. [Figure 36] 10A and 10B are a plan view and a cross-sectional view showing a state in which a forced return cam of an intermediate cam gear is in contact with a reverse charge lever in the embodiment; DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0012] First, an imaging system (camera system) 100 of this embodiment will be described with reference to Figures 1 to 11. Figure 1(a) is a central cross-sectional view of the imaging system (lens-interchangeable imaging system) 100, and Figure 1(b) is a block diagram showing the electrical configuration of the imaging system 100. Components assigned the same reference numerals in Figures 1(a) and 1(b) correspond to each other.

[0013] 1, reference numeral 1 denotes an imaging device (camera body), 2 denotes a lens device (interchangeable lens) attached to the imaging device 1, 3 denotes an imaging optical system consisting of multiple lenses, 4 denotes the optical axis of the imaging optical system 3, 6 denotes an imaging element, and 9a denotes a rear display device. Also, 9b denotes an EVF (electronic viewfinder), 11 denotes electrical contacts between the imaging device 1 and the lens device 2, 12 denotes a lens system control unit provided in the lens unit 2, and 1000 denotes a focal plane shutter (shutter unit).

[0014] An imaging system 100 consisting of an imaging device 1 and a lens device 2 has an imaging means, an image processing means, a recording / playback means, and a control means. The imaging means includes an imaging optical system 3, an image sensor 6, and a focal plane shutter 1000. The image processing means has an image processing unit 7. The recording / playback means includes a memory means 8 and a display means 9 (rear display device 9a, EVF 9b). The control means includes a camera system control circuit (control unit) 5, an operation detection unit 10, a lens system control circuit 12, and a lens driving means 13. The lens driving means 13 can drive a focusing lens, a blur correction lens, an aperture, etc.

[0015] The imaging means is an optical processing system that forms an image of light from an object on the imaging surface of the imaging element 6 via the imaging optical system 3. The focal plane shutter 1000 controls the amount of exposure to the imaging element 6 by moving a front shutter curtain 700 and a rear shutter curtain 800, which will be described later. The imaging element 6 photoelectrically converts the optical image formed via the imaging optical system 3.

[0016] The image processing unit 7 has an internal A / D converter, white balance adjustment circuit, gamma correction circuit, interpolation calculation circuit, etc., and can generate images for recording. The image processing unit 7 is provided with color interpolation processing means, which performs color interpolation (demosaicing) processing on the Bayer array signal to generate a color image. The image processing unit 7 also compresses images, videos, audio, etc. using a predetermined method. The memory means 8 has a storage unit. The camera system control circuit 5 outputs to the recording unit of the memory means 8 and displays an image to be presented to the user on the display means 9.

[0017] The camera system control circuit 5 generates and outputs timing signals for image capture. It controls the image capture system, image processing system, and recording / playback system in response to external operations. For example, an operation detection unit 10 detects the pressing of a shutter release button (not shown) and controls the driving of the image sensor 6, the operation of the image processing unit 7, and compression processing. It also controls an information display device that displays information using display means 9. The rear display device 9a is a touch panel and is connected to the operation detection unit 10.

[0018] An image processing unit 7 is connected to the camera system control circuit 5, and determines the appropriate focal position and aperture value based on the signal from the image sensor 6. In other words, the camera system control circuit 5 performs photometry and distance measurement based on the signal from the image sensor 6, and determines the exposure conditions (F-number, shutter speed, etc.). The camera system control circuit 5 issues commands to a lens system control circuit 12 via electrical contacts 11, and the lens system control circuit 12 appropriately controls a lens driving means 13. As described above, still images and videos can be taken by controlling the operation of each unit of the imaging device 1 in response to user operations on the operation detection unit 10.

[0019] FIG. 2 is a perspective view of focal plane shutter 1000. FIGS. 3(a) and 3(b) are exploded perspective views of focal plane shutter 1000. Focal plane shutter 1000 uses a base plate 910 as a basic support, with each component mounted on base plate 910. Base plate 910 and partition plate 20 form a travel space for shutter front curtain (front blade member) 700. Cover plate 920 and partition plate 20 form a travel space for shutter rear curtain (blade member, rear blade member) 800. An opening 910a is formed in base plate 910. An opening 20a and an opening 920a that overlap with opening 910a are formed in partition plate 20 and cover plate 920, respectively. During photography, a light beam transmitted through lens device 2 passes through opening 920a, opening 20a, and opening 910a in that order, exposing image sensor 6. The base plate 910 is formed with a front drive shaft 910b to which the front drive lever unit 400 is attached, and a rear drive shaft 910c to which the rear drive lever unit (drive member) 500 is attached.

[0020] In addition, the charge system component group 300, the MG base plate unit 200, the flex cable 30, and the brake unit 600 are attached to the base plate 910. The flex cable 30 is provided with a leading curtain detection photointerrupter 31, a trailing curtain detection photointerrupter 32, a phase detection photointerrupter 33, a phase detection photointerrupter 34, and a pulse detection photointerrupter 35.

[0021] The MG base plate 210 holds a lead yoke 220, a coil 230, a rear yoke 221, a coil 231, and a worm 260. The lead yoke 220 and the coil 230, and the rear yoke 221 and the coil 231, become electromagnets when the coils are energized, and can attract a lead armature 450 and a rear armature 550, which will be described later. In this embodiment, the lead yoke 220 and the coil 230 constitute a lead holding means that attracts the lead armature 450 in an energized state and holds the lead driving lever (lead driving member) 410. The rear yoke 221 and the coil 231 constitute a rear holding means that attracts the rear armature 550 in an energized state and holds the rear driving lever (rear driving member) 510.

[0022] The half-moon rubber 940 is used as a buffer member for the rear drive lever unit 500. The half-moon rubber 960 and the rubber cover 950 are combined and used as a buffer member for the front drive lever unit 400. The rubber cover 950 has lower adhesion than the half-moon rubber 960, and is arranged to make it easier for the front blade lever (blade operating member) 420 to follow the front drive lever (drive member) 410 at the timing when charging starts.

[0023] The leading curtain arm rubber 970 is used to absorb shock when the leading shutter curtain 700 (described later) receives an arm portion thereof and reduces impact. The leading curtain arm rubber cover 971 is used to protect the surface of the leading curtain arm rubber 970 to prevent abrasion caused by contact between the leading main arm 750 and the leading curtain arm rubber 970. The trailing curtain arm rubber 980 is used to absorb shock when the trailing shutter curtain 800 (described later) receives an arm portion thereof and reduces impact. The trailing curtain arm rubber cover 981 is used to protect the surface of the trailing curtain arm rubber 980 to prevent abrasion caused by contact between the rear sub-arm 860 and the trailing curtain arm rubber 980. The blade tip rubber 990 is used to absorb shock when the leading shutter curtain 700 completes its travel.

[0024] The leading shutter curtain 700 forms a parallel link with a leading main arm 750, a leading sub-arm 760, a first leading blade 710, a second leading blade 720, and a third leading blade 730. Each blade and arm is pivotally supported by a blade caulking dowel 780. A leading backlash compensation spring (first biasing member) 770 is a spring for eliminating backlash at the mating portion (described later) between the leading driving lever unit 400 and the leading shutter curtain 700, and biases the leading shutter curtain 700 counterclockwise in FIG. 3(a). At the same time, the leading backlash compensation spring 770 biases the leading blade lever 420 toward the leading driving lever 410 via the blade. A mating portion 750b of the leading main arm 750 is mated with a leading main arm shaft 910j. A mating portion 760a of the leading sub-arm 760 is mated with a leading sub-arm shaft 910k. The shutter front curtain 700 is movable between a shielding state in which it shields the opening 910a and a retracted state in which it retracts from the opening 910a.

[0025] The rear shutter curtain 800 is movable between a shielding state in which it shields the opening 910a and a retracted state in which it retracts from the opening 910a, and transitions from the retracted state to the shielding state during exposure. The rear shutter curtain 800 forms a parallel link with a rear main arm 850, a rear sub-arm 860, a first rear blade 810, a second rear blade 820, and a third rear blade 830. Each blade and arm is pivotally supported by a blade caulking dowel 880. The rear backlash compensation spring 870 is a spring for eliminating backlash at a fitting portion (described later) between the rear drive lever unit 500 and the rear shutter curtain 800, and biases the rear shutter curtain 800 counterclockwise in FIG. 3(a). The rear main arm 850 has a fitting portion 850b that fits with the rear main arm shaft 910l at the rotation center, and a fitting portion 850a that fits with the rear drive pin 510b at a portion that is a predetermined distance away from the rotation center. The rear sub-arm 860 has a fitting portion 860a that fits with the rear sub-arm shaft 910m. The shutter rear curtain 800 is movable between a blocking state in which it blocks the opening 910a and a retracted state in which it retracts from the opening 910a.

[0026] Lead drive lever 410 and lead blade lever 420 are coaxially pivotally supported on lead drive shaft 910b so as to be able to rotate back and forth, and are configured to be able to rotate independently. Lead drive pin 420b of lead blade lever 420 passes through elongated hole 910n of base plate 910 and fits into fitting portion 750a at a portion a predetermined distance from the center of rotation so that it can move integrally with lead main arm 750.

[0027] The drive spring (biasing member, second biasing member) 411 is a torsion spring for operating the front driving lever unit 400 and the front shutter curtain 700, and biases the front shutter curtain 700 in the clockwise direction in FIG. 3(a). The fixed end of the spring is incorporated into the adjuster gear 430, so that the spring force can be adjusted with the worm 260. The rear driving lever 510 is pivotally supported on the rear driving shaft 910c so as to be able to rotate back and forth. The rear driving pin 510b of the rear driving lever 510 passes through an elongated hole 910o in the base plate 910 and fits into a fitting portion 850a at a portion of the rear driving lever 510 that is a predetermined distance from the rotation center so that the rear driving lever 510 can move integrally with the rear main arm 850. The drive spring (biasing member, third biasing member) 511 is a torsion spring for operating the rear drive lever unit 500 and the rear shutter curtain 800, and biases the rear shutter curtain 800 in the clockwise direction in Figure 3(a). In addition, by incorporating the fixed end of the spring into the adjuster gear 530, the spring force can be adjusted with the worm 260.

[0028] 4 is a perspective view showing how the charging system parts group 300 is assembled to the base plate 910. Charging is the operation of transmitting the power (driving force) supplied from the motor 340 to the front driving lever unit 400 and the rear driving lever unit 500 via gears, etc., and returning them from the travel completion position to the set position where charging is complete against the drive springs 411 and 511. The rotation direction of the motor 340 during this operation is referred to as the forward direction, and rotation in the opposite direction is referred to as the reverse direction.

[0029] In this embodiment, a control method using PWM (Pulse Width Modulation) is used. In the PWM control method, the amplitude of the drive voltage applied to the motor 340 is kept constant, and the time width of the pulse that changes in a rectangular wave shape within a fixed period is changed to change the effective voltage of the motor 340, thereby controlling the motor 340. In the following explanation, the effective voltage is defined as the voltage applied to the motor.

[0030] As shown in FIGS. 3(b) and 4, a pulse plate 342 having multiple blades and a pulse detection photointerrupter 35 are provided coaxially with the motor 340. The pulse plate 342 rotates together with the motor 340 as the motor 340 rotates, and the rotation of the blades of the pulse plate 342 repeatedly blocks and transmits light to the pulse detection photointerrupter 35. The rotation speed of the motor 340 can be detected from the interval between the waveforms of the output generated by the light blocking and transmission of the pulse detection photointerrupter 35. In this embodiment, the pulse plate 342 and the pulse detection photointerrupter 35 are used to detect the rotation speed of the motor 340, but this configuration does not necessarily have to be the pulse plate 342 and the pulse detection photointerrupter 35. The pulse plate 342 and the pulse detection photointerrupter 35 constitute a rotation speed detection means for detecting the rotation speed of the motor 340.

[0031] A pinion gear 311 is attached to the motor 340, and torque generated by the motor 340 is transmitted to the gear group via this pinion gear 311. Directly meshing with the pinion gear 311 is an idle gear 312 rotatably supported on an idle gear shaft 910d of the main plate 910. A gear cover 341 covers the idle gear 312 to prevent it from protruding in the thrust direction. The idle gear 312 is coupled to a first gear 313 rotatably supported on a first gear shaft 910e, thereby reducing its speed. The first gear 313 is coupled to a second gear 314 rotatably supported on a second gear shaft 910f, thereby further reducing its speed. The second gear 314 is coupled to a leading curtain charge cam gear (charge member, leading charge member) 315 rotatably supported on a leading cam gear shaft 910g.

[0032] The leading blade charge cam gear 315, at a predetermined cam phase, performs a charging operation of the leading drive lever 410 and the leading brake lever (braking member) 620 and a lock release operation of retracting the first locking lever 160 out of the travel path of the leading blade lever 420. The leading blade charge cam gear 315 is connected to an intermediate cam gear 316 that is rotatably supported on an intermediate cam gear shaft 910h.

[0033] The intermediate cam gear 316 performs a lock release operation to retract the second locking lever 170 out of the travel path of the leading blade lever 420 and a retraction operation of the one-way lever 320 at a predetermined cam phase when the motor 340 rotates in the forward direction. On the other hand, when the motor 340 rotates in the reverse direction, the reverse charge lever 321 is actuated via the one-way lever 320 at a predetermined cam phase, and the leading blade lever 420 and the shutter leading curtain 700 are moved from the shooting standby position to the travel completion position. This operation is called a reverse charge operation. The intermediate cam gear 316 is rotatably supported by the rear cam gear shaft 910i and is connected to the rear curtain charge cam gear (charge member, rear charge member) 317.

[0034] The rear curtain charge cam gear 317 performs a charging operation on the rear drive lever 510 and the rear brake lever (braking member) 630 at a predetermined cam phase. The front curtain charge cam gear 315, the intermediate cam gear 316, and the rear curtain charge cam gear 317 are all set to have the same number of teeth. However, this embodiment is not limited to this, and the number of teeth of the intermediate cam gear 316 may be an integer multiple of the number of teeth of each of the front curtain charge cam gear 315 and the rear curtain charge cam gear 317.

[0035] In this embodiment, the second locking lever 170, the one-way lever 320, and the reverse charge lever 321 are operated by an intermediate cam gear 316. Furthermore, the leading drive lever unit 400 and the rear drive lever unit 500 are operated by a leading curtain charge cam gear 315 and a rear curtain charge cam gear 317. Therefore, the second locking lever 170, the one-way lever 320, and the reverse charge lever 321 can operate in conjunction with the leading drive lever unit 400 and the rear drive lever unit 500.

[0036] The intermediate cam gear 316 and the trailing curtain charge cam gear 317 are provided with a PI light shielding portion 316c and a PI light shielding portion 317d (see FIG. 8, which will be described later) for shielding the phase detection photointerrupter 33 and the phase detection photointerrupter 34, respectively, so that the cam phase can be determined.

[0037] FIG. 5 is an exploded perspective view of the brake unit 600. A brake base plate 610 is provided with a brake shaft 610a and a brake rubber shaft 610b on the leading and trailing curtain sides, respectively, and is fixed to the base plate 610 with screws 660. A friction sheet 651, leading brake lever 620 (rear brake lever 630), friction sheet 651, brake presser plate 640, leaf spring 652, and collar member 653 are layered on the brake shaft 610a in this order and fixed with brake screws 654. The thickness of the collar member 653 can be finely adjusted, so the compression amount (compression force) of the leaf spring 652 can be adjusted accordingly. In this way, the braking force can be adjusted by adjusting the friction force between the friction sheet 651 and the leading brake lever 620 (rear brake lever 630).

[0038] A brake rubber 650 is supported on the brake rubber shaft 610b and is prevented from coming off by a brake presser plate 640. The leading brake lever 620 (rear brake lever 630) is rotated by the leading drive lever unit 400 (rear drive lever unit 500) and stops when it comes into contact with the brake rubber 650. The brake unit 600 is fixed to the base plate 910 in an assembled state with a screw 660. In this embodiment, there are no parts that overlap on the projected area in the removal direction of the brake unit 600 (the direction of arrow A in FIG. 5). This configuration makes it easy to replace the brake unit 600 with respect to the base plate 910.

[0039] 6 is an exploded perspective view of the lead driving lever unit 400. The lead driving lever unit 400 is divided into two parts: a lead driving lever 410 and a lead blade lever 420. A lead armature (first movable iron piece) 450 is crimped and held by locally deforming the tip of a lead armature shaft 460, sandwiching the lead driving lever 410 and armature spring 440. This armature unit can be charged by a small amount in the direction of compressing the armature spring 440 relative to the lead driving lever 410.

[0040] Incidentally, since multiple parts are involved in the charging operation of the drive lever, it is difficult to bring the leading armature 450 into exact contact with the attraction surface of the leading yoke 220. Therefore, a mechanism is provided to allow a surplus in the charge stroke of the leading drive lever 410 by the leading curtain charge cam gear 315 beyond the point at which the leading armature 450 comes into contact with the leading yoke 220, and then absorb the excess charge. This mechanism uses an armature spring 440, a leading armature 450, and a leading armature shaft 460. This configuration is the same as that of a rear drive lever unit 500 shown in FIG. 7, which will be described later.

[0041] The rollers 410d and 410e are respectively pushed by a cam 315a and a cam 315b (see FIG. 14, which will be described later) of the leading blade charge cam gear 315. The leading blade lever 420 is fitted to a leading blade lever fitting shaft 410a of the leading driving lever 410. The driving lever abutment portion 420a abuts against a leading blade lever abutment portion 410b of the leading driving lever 410, and during travel, the leading driving lever 410 and the leading blade lever 420 travel together.

[0042] The leading drive pin 420b engages with the leading main arm 750 to drive the leading shutter curtain 700. In addition, the leading blade lever 420 is urged in a direction approaching the leading drive lever 410 by the urging force from the leading backlash compensating spring 770 hooked on the leading sub-arm 760.

[0043] The locked portion 420c can be locked by the first locking lever 160. This acts to prevent the blades from bounding when the leading shutter curtain 700 travels from the blade-extended state to the blade-superposed state. In addition, the locked portion 420d can be locked by the second locking lever 170. The second locking lever 170 acts to prevent the leading shutter curtain lever 420 and leading shutter curtain 700 from bounding when they return from the travel-completed state to the shooting-standby position by the spring force of the leading backlash spring 770.

[0044] The PI light blocking portion 420e is used to detect whether the travel is complete by blocking light from the leading curtain detection photointerrupter 31 near the travel completion position. The roller 420f is pressed by the pushing portion 321b of the reverse charge lever 321, causing the leading blade lever 420 to move to the travel completion position. The brake pin 420g abuts against the leading brake lever 620, thereby obtaining a braking effect due to sliding friction before the travel is complete, and can reduce the shock when the travel is complete.

[0045] 7 is an exploded perspective view of the rear drive lever unit 500. The rear armature (second movable iron piece) 550 sandwiches the rear drive lever 510 and the armature spring 540, and is crimped and held by locally deforming the tip of the rear armature shaft 560. This armature unit can be charged by a small amount relative to the rear drive lever 510 in the direction of compressing the armature spring 540.

[0046] The rear drive pin 510b engages with the rear main arm 850 to drive the rear shutter curtain 800. The PI light shielding portion 510c is used to shield the rear-curtain detection photointerrupter 32 from light and detect the state of the rear shutter curtain 800. The brake pin 510e abuts against the rear brake lever 630 to obtain a braking effect due to sliding friction before the travel is completed, thereby mitigating the shock when the travel is completed. The rollers 510f and 510g are pressed by cams 317a and 317b of the rear-curtain charge cam gear 317, respectively (see FIG. 14, which will be described later).

[0047] 8(a) and (b) are front views of the focal plane shutter 1000 with the MG base plate unit 200 removed. Fig. 8(a) shows a state in which the leading driving lever unit 400 and the trailing driving lever unit 500 are held by the leading curtain charge cam gear 315 and the trailing curtain charge cam gear 317, respectively. Fig. 8(b) shows a state in which the leading driving lever unit 400 and the trailing driving lever unit 500 are attracted by electromagnets consisting of the leading yoke 220, coil 230, and the trailing yoke 221, coil 231, respectively.

[0048] The leading drive lever 410 and the rear drive lever 510 are rotated by the leading curtain charge cam gear 315 and the rear curtain charge cam gear 317 against the biasing forces of the drive springs 411 and 511, respectively. Then, as shown in FIG. 8A, at the set position where charging is complete, the leading drive lever 410 and the rear drive lever 510 are held by the leading curtain charge cam gear 315 and the rear curtain charge cam gear 317, respectively. Thereafter, the leading curtain charge cam gear 315 and the rear curtain charge cam gear 317 rotate, and the leading drive lever 410 and the rear drive lever 510 are released from being held by the cam gears. Then, as shown in FIG. 8B, the leading drive lever 410 and the rear drive lever 510 become movable (hereinafter, this state will be referred to as the shooting standby position). At this time, the leading armature 450 and the trailing armature 550 provided on the leading drive lever 410 and the trailing drive lever 510 are energized and held by electromagnets consisting of the leading yoke 220, the coil 230 and the trailing yoke 221, the coil 231, respectively.

[0049] 9(a) and 9(b) are front and rear views in the set phase showing the relationship between the drive lever unit and the cam gear, the first locking lever 160, the second locking lever 170, the one-way lever 320, and the reverse charge lever 321. FIGS. 10(a) and 10(b) are front and rear views when charging of the one-way lever by the intermediate cam gear is complete, showing the state when retraction of the one-way lever 320 by the intermediate cam gear 316 is complete. FIGS. 11(a) and 11(b) are front and rear views when reverse charging of the leading blade lever 420 by the reverse charge lever 321 is complete, showing the state when reverse charging of the leading blade lever 420 by the reverse charge lever 321 is complete.

[0050] A rotation hole portion 160c of the first locking lever 160 is rotatably supported by the base plate 910, and the first locking lever 160 is urged counterclockwise around the rotation hole portion 160c in FIG. 9A by an urging spring 161. The operated portion 160a is rotated clockwise around the rotation hole portion 160c in FIG. 9A by a cam 315d of the leading blade charge cam gear 315 against the urging force of the urging spring 161, and is retracted outside the travel locus of the leading blade lever 420 (latch release operation). In addition, by locking the locked portion 420c of the leading blade lever 420 with the locking portion 160b near the travel completion position, it is possible to prevent bounding of the leading blade lever 420 during travel and to lock and maintain the leading blade lever 420 in the set phase in the normally open state.

[0051] A rotation hole portion 170d of the second locking lever 170 is rotatably supported on the base plate 910, and the second locking lever 170 is biased clockwise about the rotation hole portion 170d in Fig. 9(a) by a biasing spring 171. The actuated portion 170a is rotated counterclockwise about the rotation hole portion 170d in Fig. 9(a) by a cam 316b of the intermediate cam gear 316 against the biasing force of the biasing spring 171, and is retracted outside the travel locus of the leading blade lever 420 (latch release operation). In addition, by locking the locked portion 420d of the leading blade lever 420 with the locking portion 170b near the shooting standby position, it is possible to prevent the leading blade lever 420 from bounding during return travel, in which the leading blade lever 420 moves from the travel completion position to the shooting standby position, and during charging operation.

[0052] The rotation hole 321e of the reverse charge lever 321 is rotatably supported by the base plate 910. The rotation hole 320c of the one-way lever 320 shown in FIG. 4(a) is rotatably supported by the reverse charge lever 321, and the one-way lever 320 is rotatable on the same axis as the reverse charge lever 321.

[0053] When the motor 340 rotates forward, the intermediate cam gear 316 rotates clockwise in FIG. 10(a). The cam 316a contacts the cam follower portion 320a of the one-way lever 320 at a predetermined phase, causing the one-way lever 320 to rotate clockwise around the rotation hole 321e in FIG. 10(b). At this time, the biasing spring 322 acts between the one-way lever 320 and the reverse charge lever 321, biasing the one-way lever 320 clockwise around the rotation hole 321e in FIG. 10(a). That is, except when the reverse charge lever 321 moves the leading blade lever 420 in the second direction, the reverse charge lever 321 acts on the one-way lever 320 via the biasing spring 322. Meanwhile, the reverse charge lever 321 contacts the reverse charge locking portion 910p of the base plate 910 and remains stationary without rotating. That is, the reverse charge lever 321 does not act on other components.

[0054] When the motor 340 rotates in the reverse direction, the intermediate cam gear 316 rotates counterclockwise in FIG. 11(a), and the cam 316a comes into contact with the cam follower portion 320a of the one-way lever 320 at a predetermined phase. This action rotates the one-way lever 320 counterclockwise in FIG. 11(b). At the same time, the pushing portion 320b of the one-way lever 320 pushes the pushed portion 321a of the reverse charge lever 321, and they rotate together counterclockwise in FIG. 11(b).

[0055] Immediately after the reverse charge lever 321 starts to rotate, the unlocking portion 321c presses the pushed portion 170c of the second locking lever 170, causing the second locking lever 170 to rotate counterclockwise around the rotation hole 321e in Fig. 11(a). This action causes the second locking lever 170 to retreat from the travel path of the leading blade lever 420 and release the lock. Then, the pushing portion 321b of the reverse charge lever 321 abuts against the roller 420f of the leading blade lever 420, causing the leading blade lever 420 to rotate clockwise in Fig. 11(b) against the biasing force of the leading backlash compensating spring 770 (reverse charge).

[0056] Rotation continues until the locked portion 420c of the leading blade lever 420 passes a certain distance beyond the locking portion 160b of the first locking lever 160, and the motor 340 stops. At this time, the biasing spring 322 acts between the reverse charge lever 321 and the spring locking portion 910q of the base plate 910, biasing the reverse charge lever 321 counterclockwise in FIG. 11(a). By rotatably supporting the one-way lever 320 and the reverse charge lever 321, respectively, it is possible to cause the reverse charge lever 321 to act on the leading blade lever 420 only when the motor 340 rotates in the reverse direction. In other words, there is no need to control the motor 340 separately, for example by installing a dedicated actuator. Furthermore, there is no need for a dedicated actuator, which allows for a more compact unit. Furthermore, by changing the component on which the biasing spring 322 acts depending on whether the motor 340 is rotating forward or reverse, the biasing direction can be changed using a single component.

[0057] Thereafter, the motor 340 is rotated forward again to hold the leading drive lever 410 and the trailing drive lever 510 with the cams of the leading curtain charge cam gear 315 and the trailing curtain charge cam gear 317. When the reverse charge lever 321 returns to the standby position, the leading blade lever 420 tries to rotate clockwise in Figure 10(a) due to the biasing force of the leading backlash gathering spring 770, but the locked portion 420c is locked by the locking portion 160b of the first locking lever 160 and stops.

[0058] 10B only when the motor 340 is rotated in the reverse direction, the opening 910a of the base plate 910 can be set to an open state, thereby realizing a normally open state. In other words, without providing a dedicated actuator, it is possible to switch between a normally open system in which the opening 910a is open when the power is off and a normally closed system in which the opening 910a is closed, by switching the rotation direction of the motor 340.

[0059] Next, with reference to Figures 12 to 36, a series of operations of the focal plane shutter 1000 during image capture using the front shutter curtain 700 and rear shutter curtain 800 will be described. Figures 12(a) and 12(b) are cam diagrams showing the movement of each component and the signal status when the motor rotates forward, and Figure 12(b) is a continuation of Figure 12(a), and the two together show a series of operations. Also, figure numbers from Figures 13 to 30 are added to indicate correspondence. Figures 13 to 29 and 32 to 36 omit the motor 340 and the gear portions of the pinion gear 311, idle gear 312, first gear 313, second gear 314, idle gear 312, front curtain charge cam gear 315, and rear curtain charge cam gear 317. 13 to 30 and 32 to 36, the biasing spring 161, biasing spring 171, drive spring 411, armature spring 440, armature spring 540, front backlash compensating spring 770, and rear backlash compensating spring 870 are also omitted for simplicity of the drawings.

[0060] Figure 13 is a side view of the focal plane shutter 1000 as seen from the charge system component group 300 side. The cross-sectional view taken along line AA in Figure 13 is a cross-sectional view in which the second locking lever 170 is omitted so as to make it easier to see the cam portions of the gears, the one-way lever 320, and the reverse charge lever 321. All cross-sectional views of the state transition diagrams described below are cross-sectional views taken along line AA in Figure 13.

[0061] 14(a) and 14(b) are a plan view and a cross-sectional view showing the normally open state. In the normally open state, as shown in FIG. 14(a), the roller 410e of the front drive lever 410 is locked by the front curtain charge cam gear 315 so as to prevent counterclockwise rotation due to the biasing force of the drive spring 411. On the other hand, as shown in FIG. 14(b), the first locking lever 160 is held to the base plate 910 by the biasing force of the biasing spring 161. The front blade lever 420 is locked at the travel completion position so that the locked portion 420c is locked by the locking portion 160b of the first locking lever 160 and clockwise rotation due to the biasing force of the front backlash gathering spring 770 is prevented. Therefore, the shutter front curtain 700 is in an overlapping state, and the light beam from the lens device 2 is guided to the image sensor 6. Also, as shown in FIG. 14(a), the roller 510g held by the rear drive lever 510 is locked by the cam 317b of the rear curtain charge cam gear 317 so as to prevent counterclockwise rotation due to the biasing force of the drive spring 511.

[0062] When the power supply of the imaging apparatus 1 is turned on and a release button (not shown) is operated, current begins to be passed through the coils 230 and 231, and at the same time, current begins to be passed to the motor 340 in the forward direction. At this time, the front drive lever 410 and the rear drive lever 510 are kept energized. Next, current continues to be passed through the motor 340 (not shown), and the rotation of the motor 340 is transmitted to the pinion gear 311, the idle gear 312, the first gear 313, and the second gear 314. This causes the front curtain charge cam gear 315, the intermediate cam gear 316, and the rear curtain charge cam gear 317 to rotate, and a set release is performed, which transitions from the set phase to the shooting standby phase.

[0063] 15 is a plan view showing a state in which the cam 316b of the intermediate cam gear 316 has begun to come into contact with the actuated portion 170a of the second locking lever 170. Due to the contact of the cam 316b, the second locking lever 170 begins to retreat from the travel path of the leading blade lever 420. During the set release, the roller 410e is released from contact with the cam 315b of the leading blade charge cam gear 315. Similarly, the roller 510g is released from contact with the cam 317b of the trailing blade charge cam gear 317. Meanwhile, the respective drive levers 410, 510 continue to be energized.

[0064] 16 is a plan view showing a state in which, from the state shown in FIG. 15 , current is further applied to the motor 340 to rotate the front-curtain charge cam gear 315 and the rear-curtain charge cam gear 317, resulting in the shooting standby phase being reached. The cams 315a and 315b of the front-curtain charge cam gear 315 are retracted to outside the travel locus of the front-drive lever 410. The cams 317a and 317b of the rear-curtain charge cam gear 317 are retracted to outside the travel locus of the rear-drive lever 510. The actuated portion 170a of the second locking lever 170 abuts against the cam 316b of the intermediate cam gear 316, so that the second locking lever 170 is held in a retracted state outside the travel locus of the front-drive lever 410. Here, the front-drive lever 410 and the rear-drive lever 510 continue to be energized by the energization of the coils 230 and 231. Meanwhile, the front blade lever 420 remains in a state in which the locked portion 420c is locked by the locking portion 160b of the first locking lever 160, and the front shutter curtain 700 also remains in the overlapping state.

[0065] 17 is a plan view showing a state in which the motor 340 is further energized from the state in FIG. 16 and the operated portion 160a of the first locking lever 160 comes into contact with the cam 315d of the front curtain charge cam gear 315. The cam 315d of the front curtain charge cam gear 315 starts to come into contact with the operated portion 160a of the first locking lever 160, and the first locking lever 160 starts to rotate clockwise against the biasing force of the biasing spring 161. When the contact between the operated portion 170a of the second locking lever 170 and the cam 316b of the intermediate cam gear 316 is released, the biasing force of the biasing spring 171 causes the second locking lever 170 to return to within the travel locus of the front blade lever 420.

[0066] 18 is a plan view showing a state in which the motor 340 is further energized from the state in FIG. 17 , the leading blade charge cam gear 315 and the trailing blade charge cam gear 317 rotate, and the locking of the leading blade lever 420 by the first locking lever 160 is released. As the first locking lever 160 retreats to outside the travel path of the leading blade lever 420, the leading blade lever 420 is released from the locking of the first locking lever 160. Then, the leading blade lever 420 starts to rotate clockwise from the travel completion position toward the standby position due to the biasing force of the leading backlash compensating spring 770. At this time, the shutter leading curtain 700, which is linked to the leading blade lever 420, also starts to rotate clockwise and starts to move from the overlapping state to the deployed state. Furthermore, the contact between the actuated portion 170 a of the second locking lever 170 and the cam 316 b of the intermediate cam gear 316 is released, and the second locking lever 170 returns to within the travel locus of the leading blade lever 420 .

[0067] 19(a) and 19(b) are a plan view and a rear view showing a state in which the motor 340 is further energized from the state of FIG. 18 and the cam 315c of the leading blade charge cam gear 315 starts to abut against the cam follower 620a of the leading brake lever 620. Incidentally, as will be described later, when the leading blade lever 420 is in the standby position, the leading brake lever 620 stops within the travel trajectory of the leading blade lever 420. At a position just before the completion of travel of the leading blade lever 420 during travel, the leading brake lever 620 starts to abut against the brake pin 420g of the leading blade lever 420, rotates while abutting against the brake pin 420g until it reaches the travel completion position of the leading blade lever 420, and stops. The stop position of the leading brake lever 620 at a position just before the completion of travel of the leading blade lever 420 is called the operation standby position, and the position of the leading brake lever 620 at the travel completion position of the leading blade lever 420 is called the operation completion position.

[0068] In the normally open state of FIG. 14, the leading blade lever 420 is locked at the travel completion position, and therefore the leading brake lever 620 is stopped at the operation completion position from the normally open state of FIG. 14 to the state of FIG. 18. When the leading blade charge cam gear 315 rotates, the cam follower 620a of the leading brake lever 620 is pressed by the cam 315c of the leading blade charge cam gear 315, and the leading brake lever 620 rotates from the operation completion position to the operation standby position. The rotation speed of the leading blade lever 420 is slower than the rotation speed of the leading brake lever 620 rotated by the cam 315c of the leading blade charge cam gear 315 because the biasing force from the leading backlash compensation spring 770 is weak. Therefore, the leading brake lever 620 abuts against the brake pin 420g of the leading blade lever 420, which started to rotate earlier from the state of FIG. 18, and rotates while pushing the leading blade lever 420.

[0069] The leading curtain charge cam gear 315 further rotates, and the cam follower 620a of the leading brake lever 620 moves to the cam top of the cam 315c, causing the leading brake lever 620 to stop at the standby position. Meanwhile, the leading blade lever 420 continues to rotate at an accelerated rate due to the biasing force from the leading backlash spring 770 and the driving force pushed by the leading brake lever 620. In other words, the power of the leading curtain charge cam gear 315 is transmitted to the leading blade lever 420 via the leading brake lever 620. The rotation of the leading brake lever 620 assists the initial rotation of the leading blade lever 420, thereby realizing an increase in the speed of the return travel operation of the leading blade lever 420, which moves from the travel completion position to the standby position. This shortens the time it takes for the leading shutter curtain 700 to move from the overlapped state to the deployed state, which is effective in increasing the frame speed.

[0070] Furthermore, the biasing force of the front backlash spring 770 is a biasing force in a direction that cancels out the biasing force of the drive spring 411, and if the spring force of the front backlash spring 770 is increased in order to speed up the return travel operation, the spring force of the drive spring 411 also needs to be increased.

[0071] Therefore, with the assistance of the front brake lever 620, there is no need to increase the spring force of the front backlash-collapsing spring 770 in order to speed up the return travel operation, and accordingly there is no need to increase the spring force of the drive spring 411. As a result, it is possible to reduce the load required to charge the biasing force of the drive spring 411, which is effective in improving the frame speed (continuous shooting speed) and reducing the current value of the motor 340.

[0072] 20A and 20B are plan and cross-sectional views showing a state in which, from the state shown in FIG. 19, the motor 340 is further energized and the cam 316a of the intermediate cam gear 316 begins to abut against the cam follower portion 320a of the one-way lever 320. FIG. 20A shows a plan view of a state in which the rotating leading blade lever 420 begins to abut against the locking portion 170b of the second locking lever 170. After the locked portion 420d of the leading blade lever 420 abuts against the locking portion 170b of the second locking lever 170, the locked portion 420d pushes away the slope of the cam of the locking portion 170b, causing the leading blade lever 420 to continue rotating. FIG. 20B shows a cross-sectional view of a state in which the cam 316a of the intermediate cam gear 316 begins to abut against the cam follower portion 320a of the one-way lever 320.

[0073] As shown in Figure 9(b), the pushing portion 320b of the one-way lever 320 abuts against the pushed portion 321a of the reverse charge lever 321, and the reverse charge lever 321 abuts against the reverse charge locking portion 910p of the base plate 910. As shown in Figure 20(b), the one-way lever 320 starts to rotate counterclockwise when the cam 316a begins to abut against the cam follower portion 320a. Meanwhile, the reverse charge lever 321 abuts against the reverse charge locking portion 910p of the base plate 910 and does not operate at this time.

[0074] 20(a), the cam 317a of the rear-curtain charge cam gear 317 starts to enter the travel trajectory of the rear drive lever 510. However, because the rear drive lever 510 is in a state in which electricity is maintained, the rear-curtain charge cam gear 317 rotates without charging the rear drive lever 510 (hereinafter referred to as "idle charge").

[0075] When the motor 340 is further energized and the leading curtain charge cam gear 315 and the trailing curtain charge cam gear 317 rotate, the actuated portion 160a of the first locking lever 160 is released from contact with the cam 315d of the leading curtain charge cam gear 315. Then, due to the biasing force of the biasing spring 161, the first locking lever 160 returns to within the travel locus of the leading blade lever 420 and comes into contact with the base plate 910, thereby stopping.

[0076] FIG. 21 is a plan view showing the state in which the shutter front curtain 700 has completed its transition from the overlapped state to the deployed state. From the state shown in FIG. 20(b), the front blade lever 420 and the shutter front curtain 700 continue to rotate clockwise and return to their standby positions. When the front blade lever 420 reaches its standby position, it collides with the front drive lever 410. The impact of the collision causes the front blade lever 420 to attempt to return counterclockwise, but the locked portion 420d is locked by the locking portion 170b of the second locking lever 170. As a result, bounding of the front blade lever 420 and the shutter front curtain 700 is prevented. Therefore, by suppressing bounding during the return travel operation, transition to the next operation after the return travel is immediately possible, which is effective in increasing the frame speed. At this time, the light beam from the lens device 2 is blocked by the shutter front curtain 700.

[0077] FIG. 22 is a plan view showing a state in which the motor 340 is further energized from the state shown in FIG. 21, causing the leading driving lever unit 400 and the trailing driving lever unit 500 to reach the set phase. The one-way lever 320 releases the abutment of the cam follower portion 320a with the cam 316a of the intermediate cam gear 316, and rotates clockwise due to the biasing force of the biasing spring 322. Then, as shown in FIG. 9(b), the pushing portion 320b of the one-way lever 320 abuts against the pushed portion 321a of the reverse charge lever 321, causing the one-way lever 320 to stop. When the motor 340 is de-energized, the opening 910a is closed, resulting in a normally closed state.

[0078] When the motor 340 is further energized and the leading curtain charge cam gear 315 and the trailing curtain charge cam gear 317 rotate, the state shifts to release of the set, similar to the state in FIG. 15 . During release of the set, the roller 410e is released from contact with the cam 315b of the leading curtain charge cam gear 315. Similarly, the roller 510g is released from contact with the cam 317b of the trailing curtain charge cam gear 317. Meanwhile, the drive levers 410 and 510 remain energized. The cam 316b of the intermediate cam gear 316 comes into contact with the actuated portion 170a of the second locking lever 170, and the second locking lever 170 moves in a direction retracting from the travel locus of the leading blade lever 420.

[0079] When the motor 340 is further energized and the front curtain charge cam gear 315 and the rear curtain charge cam gear 317 rotate, the state shown in Figure 23 is reached, and as will be described later, energization to the motor 340 is stopped. Figure 23 is a plan view showing the state when stopped in the shooting standby phase.

[0080] 12, the phase detection photointerrupter 34 is switched from transmission (Hi in FIG. 12) to light blocking (Lo in FIG. 12) by the PI light blocking portion 317d of the rear-curtain charge cam gear 317. Meanwhile, the phase detection photointerrupter 33 remains light blocking (Lo in FIG. 12) by the PI light blocking portion 316c of the intermediate cam gear 316. When the phase detection photointerrupter 34 detects the switch from transmission to light blocking and detects that the phase detection photointerrupter 33 remains light blocked, the camera system control circuit 5 stops the supply of electricity to the motor 340.

[0081] The cams 315a and 315b of the leading charge cam gear 315 are retracted to outside the travel locus of the leading drive lever 410. The cams 317a and 317b of the trailing charge cam gear 317 are retracted to outside the travel locus of the rear drive lever 510. The actuated portion 170a of the second locking lever 170 abuts against the cam 316b of the intermediate cam gear 316, so that the second locking lever 170 is held in a retracted state outside the travel locus of the leading drive lever 410. Here, the leading drive lever 410 and the rear drive lever 510 are biased counterclockwise in FIG. 23 by the drive springs 411 and 511, respectively, but are kept energized by energizing the coils 230 and 231. The camera system control circuit 5 then cuts off the power to the coil 230, and exposure of the image sensor 6 begins. The camera's time control is performed by changing the interval at which the current is cut off to the coil 230 on the front curtain side and the coil 231 on the rear curtain side.

[0082] 23, after the power supply to the coil 230 is cut, the front driving lever unit 400 and the front blade lever 420 rotate counterclockwise together. The front shutter curtain 700 also starts to rotate counterclockwise, and transitions from the expanded state to the overlapped state.

[0083] 24A and 24B are a plan view and a rear view showing a state in which the leading drive lever unit 400 and the leading blade lever 420 have traveled and completed their travel. As shown in FIG. 24A, when the leading blade lever 420 is near the travel completion position, the locked portion 420c pushes aside the locking portion 160b of the first locking lever 160 and continues to rotate. Immediately afterwards, the first locking lever 160 is returned to within the travel path of the leading blade lever 420 by the biasing spring 161.

[0084] 24(b), similarly, near the travel completion position, the brake pin 420g of the leading blade lever 420 abuts on the leading brake lever 620 and rotates integrally therewith. At this time, the energy of the biasing force by the drive spring 411 is offset by the frictional force between the leading brake lever 620 and the friction sheet 651, and the leading blade lever 420 rotates while gradually slowing down.

[0085] When the leading blade lever 420 reaches the travel completion position, the leading drive pin 420b of the leading blade lever 420 abuts against the rubber cover 950 shown in FIG. 3, and the leading blade lever 420 and the leading drive lever 410 stop rotating. At the same time, the leading main arm 750 of the shutter leading curtain 700 abuts against the leading curtain arm rubber cover 971 shown in FIG. 3 at the travel completion position and stops rotating. The leading curtain arm rubber cover 971 abuts against the leading curtain arm rubber 970, and the leading curtain arm rubber 970 absorbs the impact of the leading shutter curtain 700 during travel, which is effective in preventing blade damage during durability testing. In addition, at the same time that the leading blade lever 420 reaches the travel completion position, the leading brake lever 620 abuts against the brake rubber 650 shown in FIG. 5, and the leading brake lever 620 stops rotating.

[0086] The leading blade lever 420 and the leading drive lever 410 bound to rotate clockwise due to the impact when the leading drive pin 420b abuts against the rubber cover 950. However, the bounding is prevented by the locked portion 420c of the leading blade lever 420 being locked by the locking portion 160b of the first locking lever 160 that has returned to within the travel path of the leading blade lever 420.

[0087] Therefore, the deceleration of the leading blade lever 420 by the leading brake lever 620 and the bounding prevention mechanism by the first locking lever 160 can shorten the bounding time of the leading blade lever 420 and speed up the start of the subsequent charging operation. This is therefore effective in increasing the frame speed (continuous shooting speed).

[0088] Incidentally, during the return travel operation of the leading blade lever 420, the leading drive lever 410 is kept energized. However, when the leading blade lever 420 reaches the standby position, the leading blade lever 420 collides with the leading drive lever 410, causing the leading drive lever 410 to deviate from its initial position due to the impact. If the power supply is cut and the leading blade lever 420 is allowed to travel in this state, the deviated position will be unstable, and the travel operation for each photograph will be unstable. In this embodiment, after the return travel operation of the leading blade lever 420, the roller 410e of the leading drive lever 410 abuts against the cam top of the cam 315b of the leading curtain charge cam gear 315, and then the leading drive lever 410 is set to the release position. As a result, the leading drive lever 410, which has been deviated due to the return travel operation of the leading blade lever 420, is reset to its initial position. This stabilizes the travel operation for each photograph, improving shutter accuracy.

[0089] When the camera system control circuit 5 cuts off the power supply to the coil 231 after a predetermined interval, the rear drive lever unit 500 starts to rotate counterclockwise.

[0090] 25 is a plan view and a rear view showing the state in which the rear drive lever unit 500 has traveled and completed its travel. When it approaches the position just before the travel completion, the brake pin 510e of the rear drive lever 510 abuts the rear brake lever 630, gradually slowing down. When the rear drive pin 510b abuts the half-moon rubber 960, it reaches the travel completion position and the rear drive lever unit 500 stops rotating. At the same time that the rear drive lever 510 reaches the travel completion position, the rear brake lever 630 abuts the brake rubber 650 shown in FIG. 5, and the rear brake lever 630 stops rotating.

[0091] The stop position of the rear brake lever 630 when the rear drive lever 510 is at a position just before the completion of travel is called the action standby position, and the stop position of the rear brake lever 630 when the rear drive lever 510 is at the travel completion position is called the action completion position. The rear drive lever 510 rotates between the action standby position and the action completion position.

[0092] After a predetermined time has elapsed since the exposure operation by the front shutter curtain 700 and the rear shutter curtain 800 is completed, the camera system control circuit 5 resumes supplying electricity to the motor 340 in order to charge the motor 340 in preparation for the next image capture. When the supply of electricity to the motor 340 is resumed, the front curtain charge cam gear 315 and the rear curtain charge cam gear 317 both rotate counterclockwise, and the intermediate cam gear 316 rotates clockwise.

[0093] 26 is a plan view showing a state in which the cam 315d of the leading blade charge cam gear 315 operates the operated portion 160a of the first locking lever 160 to release the lock. When the cam 315d of the leading blade charge cam gear 315 abuts, the first locking lever 160 retreats to outside the travel path of the leading blade lever 420, and the leading blade lever 420 is released from the locking of the first locking lever 160. Then, the leading blade lever 420 starts to rotate clockwise from the travel completion position toward the standby position due to the biasing force of the leading backlash compensating spring 770. At this time, the leading shutter blade 700, which is linked to the leading blade lever 420, also starts to rotate counterclockwise and starts to move from the overlapping state to the deployed state.

[0094] Furthermore, the cam 315a of the leading blade charge cam gear 315 starts to come into contact with the roller 410d of the leading blade lever 410, causing the leading blade lever 410 to rotate clockwise. At this time, the leading blade lever 410 and the leading blade lever 420 are rotating in the same direction, but since the biasing force from the leading backlash compensation spring 770 that rotates the leading blade lever 420 is weak, the leading blade lever 410 rotates ahead of the leading blade lever 420.

[0095] 27 is a cross-sectional view and a rear view showing a state in which, from the state in FIG. 26, power is further applied to the motor 340 and the cam 315c of the leading curtain charge cam gear 315 begins to abut against the cam follower 620a of the leading brake lever 620. As in FIG. 19, as shown in FIG. 27(a), the cam 315c of the leading curtain charge cam gear 315 presses the cam follower 620a of the leading brake lever 620, and the leading brake lever 620 rotates from the operation completion position to the operation standby position.

[0096] As shown in FIG. 27(b), the leading brake lever 620 comes into contact with the brake pin 420g of the leading blade lever 420, which has started to rotate first from the state of FIG. 26, and rotates while pushing the leading blade lever 420. The leading blade charge cam gear 315 further rotates, and the cam follower 620a of the leading brake lever 620 moves to the cam top of the cam 315c, causing the leading brake lever 620 to stop at the operation standby position. Meanwhile, the leading blade lever 420 continues to rotate at an accelerated speed due to the biasing force from the leading backlash compensation spring 770 and the driving force pushed by the leading brake lever 620. Then, the accelerated leading blade lever 420 catches up with the leading drive lever 410, which is rotating in contact with the leading blade charge cam gear 315, and then continues to rotate together with it.

[0097] Therefore, by assisting the initial rotation of the leading blade lever 420 with the rotation of the leading brake lever 620, the leading blade lever 420 can catch up with the leading drive lever 410 and rotate together with it. As a result, it is possible to reduce the time required for the rotational movements of both the leading blade lever 420 and the leading drive lever 410, which is effective in increasing the frame speed (continuous shooting speed).

[0098] When the motor 340 is energized from the state shown in FIG. 27 and the leading charge cam gear 315 and the trailing charge cam gear 317 rotate, the state shown in FIG. 28 is reached. FIG. 28 is a plan view showing a state in which the leading brake lever 620 is stopped at the operation standby position and the cam 317a of the trailing charge cam gear 317 begins to abut against the roller 510f of the rear drive lever 510. Note that FIG. 28 omits the second locking lever 170 so that the intermediate cam gear 316 and the one-way lever 320 can be seen. The rear drive lever 510 begins to rotate clockwise due to the cam 317a. Because the rear drive lever 510 begins to rotate after the leading brake lever 620 has completed rotation, load distribution is achieved. Load distribution eliminates the need for a high-torque motor, enabling motor miniaturization and cost reduction, which is also effective in reducing the size of the camera.

[0099] Furthermore, the cam 316a of the intermediate cam gear 316 begins to abut against the cam follower portion 320a of the one-way lever 320. As shown in FIG. 28(b), the cam 316a rotates the one-way lever 320 counterclockwise, but the reverse charge lever 321 abuts against the reverse charge locking portion 910p of the base plate 910 shown in FIG. 9(b) and does not operate at this time. The actuated portion 160a of the first locking lever 160 is released from abutment with the cam 315d of the leading blade charge cam gear 315. Then, due to the biasing force of the biasing spring 161, the first locking lever 160 returns to within the travel locus of the leading blade lever 420 and abuts against the base plate 910.

[0100] When the motor 340 is further energized and the leading-curtain charge cam gear 315 and trailing-curtain charge cam gear 317 rotate, as described above, the roller 410d of the leading-curtain drive lever 410 is released from contact with the cam 315a of the leading-curtain charge cam gear 315. Meanwhile, the roller 410e of the leading-curtain drive lever 410 comes into contact with the cam 315b of the leading-curtain charge cam gear 315, and continues to rotate as power is transmitted.

[0101] When the leading blade lever 420 is near the return travel completion position, the locked portion 420c pushes aside the locking portion 170b of the second locking lever 170, and continues to rotate. Immediately afterwards, the second locking lever 170 is returned to the travel path of the leading blade lever 420 by the biasing spring 171, and comes into contact with the base plate 910. Similarly, the roller 510f of the rear drive lever 510 is released from contact with the cam 317a of the rear-curtain charge cam gear 317. Meanwhile, the roller 510g of the rear drive lever 510 is brought into contact with the cam 317b of the rear-curtain charge cam gear 317, and rotates as power is transmitted thereto.

[0102] FIG. 29 is a plan view and a cross-sectional view showing the set phase state in which the leading drive lever 410, the leading blade lever 420, and the trailing drive lever 510 are all fully charged. As shown in FIG. 29(a), the cam 315b of the leading blade charge cam gear 315 moves to the cam top, and the leading armature 450 of the leading drive lever 410 abuts against the leading yoke 220. The leading blade lever 420, which has been driven integrally with the leading drive lever 410, attempts to return counterclockwise due to the impact of the abutment, but the locked portion 420d is locked by the locking portion 170b of the second locking lever 170. This prevents the leading blade lever 420 and the leading shutter blade 700 from bounding. As a result, it is possible to shorten the time required to transition to the next operation, which is effective in increasing the frame speed.

[0103] Meanwhile, the cam 317b of the rear curtain charge cam gear 317 moves to the cam top, and the rear armature 550 of the rear drive lever 510 abuts against the rear yoke 221. At this time, the front brake lever 620 is in the operation standby position, but the rear brake lever 630 is still in the operation completion position.

[0104] 29(b), the cam follower portion 320a of the one-way lever 320 is released from contact with the cam 316a of the intermediate cam gear 316. The one-way lever 320 rotates clockwise due to the biasing force of the biasing spring 322 and stops when it comes into contact with the pushed portion 321a of the reverse charge lever 321.

[0105] When the motor 340 is further energized and the leading-curtain charge cam gear 315 and the trailing-curtain charge cam gear 317 rotate, the process moves to release of the set. During release of the set, the roller 410e is released from contact with the cam 315b of the leading-curtain charge cam gear 315. Similarly, the roller 510g is released from contact with the cam 317b of the trailing-curtain charge cam gear 317. Meanwhile, the drive levers 410 and 510 remain energized. The cam 317c of the trailing-curtain charge cam gear 317 presses the cam follower 630a of the rear brake lever 630, causing the rear brake lever 630 to rotate from the operation completion position to the operation standby position.

[0106] Conventionally, the rear curtain charge cam gear 317 rotates the rear brake lever 630 from the operation completion position to the operation standby position simultaneously with the charging operation of the rear drive lever 510. In the present invention, the rear curtain charge cam gear 317 rotates the rear brake lever 630 from the operation completion position to the operation standby position during release, thereby distributing the load during driving. As a result, due to the load distribution, a high-torque motor is no longer required to charge the drive lever, which enables the motor to be made smaller and less expensive, leading to a more compact camera. Furthermore, the ability to shorten the charging time is also effective in increasing the frame rate.

[0107] During the release of the setting, the camera system control circuit 5 detects the rotation speed of the motor 340 using the pulse plate 342 and pulse detection photointerrupter 35 shown in FIGS. 3(b) and 4(b) and determines whether the detected rotation speed of the motor 340 is equal to or greater than a certain threshold. Based on the result of this determination, the voltage applied to the motor 340 is adjusted. This allows the rotation speed of the motor 340 to be maintained constant, and the rotation speeds of the front-curtain charge cam gear 315 and the rear-curtain charge cam gear 317 can be controlled to a constant (predetermined) rotation speed during the release of the setting. Therefore, even if the load during the release of the setting fluctuates significantly due to variations in the braking force of the rear brake lever 630 or changes in braking force under different temperature conditions, the release time can be kept constant, and a high frame rate can be stably achieved. Furthermore, by maintaining a constant rotation speed of the front-curtain charge cam gear 315, the speed at which the roller 410e of the front drive lever 410 and the cam 315b of the front-curtain charge cam gear 315 release from contact with each other during the release of the setting is constant.

[0108] Therefore, it is possible to prevent the front driving lever 410 from moving to a position deviated from the charge completion position due to the momentum generated when the contact is released, which leads to stability in the travel operation of the front shutter curtain 700 and is effective in improving shutter accuracy. The same applies to the rear driving lever 510.

[0109] Furthermore, by keeping the rotation speed of the motor 340 constant, it is possible to suppress variations in the stopping position of the motor 340 after the power supply to the motor is stopped. Therefore, there is no need to ensure a wide run-up range for the leading curtain charge cam gear 315 and the trailing curtain charge cam gear 317 after the motor is de-energized. This makes it possible to lengthen the charge range of each drive lever, and by reducing the cam lift angle of the leading curtain charge cam gear 315 and the trailing curtain charge cam gear 317, it is possible to reduce the load during charging. This is therefore effective in increasing the frame speed.

[0110] 12(b), the phase detection photointerrupter 33 and the phase detection photointerrupter 34 detect the shooting standby phase, and the camera system control circuit 5 stops the supply of power to the motor 340. The cams 315a and 315b of the leading-curtain charge cam gear 315 are retracted to outside the travel locus of the leading-drive lever 410. The cams 317a and 317b of the trailing-curtain charge cam gear 317 are retracted to outside the travel locus of the trailing-drive lever 510. The actuated portion 170a of the second locking lever 170 is driven by the cam 316b of the intermediate cam gear 316, and is held in a retracted state outside the travel locus of the leading-drive lever 410.

[0111] Here, the front drive lever 410 and the rear drive lever 510 are biased counterclockwise by the drive springs 411 and 511, respectively, but are kept energized by the current supplied to the coil 230. Here, the operation detection unit 10 determines whether the shutter release button has been pressed. In the case of continuous shooting with the shutter release button held down by the photographer, the focal plane shutter 1000 then cuts off the current to the coil 230, and exposure of the image sensor 6 begins. The camera's shutter speed control is performed by varying the intervals at which current is cut to the coil 230 on the front curtain side and the coil 231 on the rear curtain side. Thereafter, current begins to be supplied to the motor 340, and the operation of the cam diagram in FIG. 12(b) is repeated. On the other hand, if the photographer has not pressed the shutter release button, after the shooting standby phase of the cam diagram in Figure 30 described below is reached, the camera system control circuit 5 temporarily stops supplying electricity to the motor 340 and then starts supplying electricity to the motor 340 in the reverse direction.

[0112] Below, we will explain the series of operations of the focal plane shutter 1000 when the motor 340 is energized in the reverse direction and then in the forward direction. Figure 30 is a cam diagram that shows the movement of each part and the signal status when the motor 340 is energized in the reverse direction and then in the forward direction. Figures 31 to 36 are also labeled with the same reference numbers as Figures 14 and 23 to indicate correspondence.

[0113] When the supply of electricity to the motor 340 in the reverse direction starts, both the front curtain charge cam gear 315 and the rear curtain charge cam gear 317 shown in Fig. 23 rotate clockwise, and the intermediate cam gear 316 rotates counterclockwise. At this time, the second locking lever 170 abuts against the cam 316b of the intermediate cam gear 316 and is in the cam top state. Furthermore, electricity continues to be supplied to the front curtain side coil 230 and the rear curtain side coil 231, and the front driving lever 410 and the rear driving lever 510 are each kept in a state of being supplied with electricity until they reach the normally open state.

[0114] When power supply to the motor 340 in the reverse direction starts from the state of Fig. 23, a return operation from the shooting standby phase to the set phase occurs, and the state transitions to the state of Fig. 31. Fig. 31 is a plan view showing a state in which the intermediate cam gear 316 rotates and the abutment between the actuated part 170a of the second locking lever 170 and the cam 316b of the intermediate cam gear 316 is released. At this time, the second locking lever 170 is in a state in which it can lock the locked part 420d of the leading blade lever 420.

[0115] When the intermediate cam gear 316 further rotates from the state shown in FIG. 31, the state transitions to the state shown in FIG. 32. FIG. 32 is a plan view and a cross-sectional view showing a state in which the cam 316a of the intermediate cam gear 316 abuts against the cam follower portion 320a of the one-way lever 320 and reverse charging has begun. As shown in FIG. 32(b), the pushing portion 320b of the one-way lever 320 pushes the pushed portion 321a of the reverse charge lever 321, causing them to rotate clockwise together. Also, as shown in FIG. 32(a), the reverse charge lever 321 is in a state in which the release portion 321c abuts against the pushed portion 170c of the second locking lever 170. After this, if the motor 340 continues to be energized, the second locking lever 170 is charged counterclockwise via the one-way lever 320 and the reverse charge lever 321, transitioning to a state in which it is retracted outside the travel path of the leading blade lever 420. In this way, when the motor rotates in the reverse direction, the second locking lever 170 is released from its lock by the reverse charge lever 321, which operates only when the motor rotates in the reverse direction. On the other hand, when the motor rotates in the forward direction, the second locking lever 170 is released from its lock by the cam 316b of the intermediate cam gear 316. Therefore, in the reverse charge phase shown in FIG. 30, the second locking lever 170 is in the retracted position. On the other hand, in the charge phase shown in FIG. 12 (which overlaps with the reverse charge phase), the second locking lever 170 can be kept in the standby position. In other words, in the charge phase shown in FIG. 12, the standby phase of the second locking lever 170 can be secured for a long time, and the phase during which the return run bound lock is effective can be extended. This also reduces the occurrence of unnecessary waiting time until the bound settles, enabling a higher top speed.

[0116] When the intermediate cam gear 316 further rotates from the state in FIG. 32, the state transitions to the state in FIG. 33. At this time, as shown in FIG. 33(b), the pushing portion 321b of the reverse charge lever 321 is in a state in which it has begun to abut against the roller 420f of the leading blade lever 420. After this, when the motor 340 continues to be energized, the leading blade lever 420 continues to rotate counterclockwise against the biasing force of the leading backlash compensating spring 770 as the reverse charge lever 321 rotates clockwise. In this process, the leading blade lever 420 rotates while pushing aside the leading brake lever 620 via the brake pin 420g. Eventually, the roller 420f of the leading blade lever 420 moves to the cam top of the reverse charge lever 321, and the locked portion 420c of the leading blade lever 420 is locked by the locking portion 160b of the first locking lever 160. When this reverse charging complete state is reached, the supply of electricity to the motor 340 in the reverse direction is stopped.

[0117] Figure 34 shows a plan view and a cross-sectional view illustrating a reverse charging completion state in which the roller 420f of the leading blade lever 420 has moved to the cam top of the reverse charge lever 321. At this time, as shown in Figure 35(b), the leading blade lever 420 has rotated to a phase where the locked portion 420c can be locked by the locking portion 160b of the first locking lever 160. In addition, the leading shutter curtain 700 is in an overlapping state. Meanwhile, the supply of electricity to the coil 230 on the leading curtain side continues, and the leading drive lever 410 is kept energized.

[0118] When the motor 340 starts to be energized in the normal direction from the state shown in FIG. 34, the leading curtain charge cam gear 315 and trailing curtain charge cam gear 317 both start to rotate counterclockwise, and the intermediate cam gear 316 starts to rotate clockwise.

[0119] 35A and 35B are plan and cross-sectional views showing a state in which the intermediate cam gear 316 rotates clockwise from the state in FIG. 34 and the roller 420f of the leading blade lever 420 moves away from the pushing portion 321b of the reverse charge lever 321. At this time, as shown in FIG. 35A, the locked portion 420c of the leading blade lever 420 is locked by the locking portion 160b of the first locking lever 160, so the shutter leading curtain 700 maintains the overlapping state. Also, as shown in FIG. 35B, the one-way lever 320 and the reverse charge lever 321 rotate counterclockwise together due to the counterclockwise biasing force of the biasing spring 322, and return to the position shown in FIG. 14. However, when the roller 420f of the leading blade lever 420 is at the cam top of the reverse charge lever 321 (reverse charge complete state), the following biasing relationship exists. That is, the cam surface of the pushing portion 321b of the reverse charge lever 321 receives lateral pressure toward the center of the intermediate cam gear shaft 910h from the front backlash biasing spring 770, which biases the leading blade lever 420 clockwise. Furthermore, an increase in frictional force due to wear on the cam surface of the pushing portion 321b over time, or an increase in lateral pressure due to component variations, may occur. In such cases, there is a concern that the counterclockwise biasing force of the biasing spring 322 alone may not be enough to return the reverse charge lever 321 to the position shown in FIG. 14. As a countermeasure against this, the intermediate cam gear 316 has a forced return cam (cam surface) 316d that forcibly returns the reverse charge lever 321 during the transition from the state shown in FIG. 34 to the state shown in FIG. 14. The forced return cam 316d moves the reverse charge lever 321 in a direction away from the leading blade lever 420. When the intermediate cam gear 316 moves the reverse charge lever 321 in a direction separating it from the reverse charge lever 321, the leading curtain charge cam gear 315 rotates the motor 340 in the same direction as when moving the leading drive lever 410.

[0120] Figure 36 is a plan view and a cross-sectional view showing the forced return cam 316d of the intermediate cam gear 316 abutting against the reverse charge lever 321, with the second locking lever 170 omitted for convenience. When the intermediate cam gear 316 further rotates clockwise, the forced return cam 316d rotates the reverse charge lever 321 counterclockwise, returning it to the position shown in Figure 14. This allows the reverse charge lever 321 to be forcibly returned. Therefore, even if the cam surface of the pushing portion 321b wears down over time, increasing friction and lateral pressure, the reverse charge lever 321 can reliably return by the movement shown by the dashed line in Figure 30. At this time, as shown in Figure 36(b), the pushing portion 320b of the one-way lever 320 abuts against the pushed portion 321a of the reverse charge lever 321, so the one-way lever 320 operates integrally with the reverse charge lever 321.

[0121] If the motor 340 continues to be energized in the forward direction from the state shown in FIG. 36, the state shown in FIG. 14 is eventually reached, and energization of the motor 340 and the coils 230 and 231 on the front and rear blades is stopped. At this time, as shown in FIG. 14(a), the roller 410e of the front driving lever 410 is locked by the front-curtain charge cam gear 315 so as to prevent counterclockwise rotation due to the biasing force of the drive spring 411. The same is true for the rear driving lever 510. Meanwhile, as shown in FIG. 14(b), the locked portion 420c of the front blade lever 420 is locked by the locking portion 160b of the first locking lever 160. Therefore, the front shutter curtain 700 is in an overlapping state, and the light beam from the lens device 2 is guided to the image sensor 6. The above-described series of operations achieves a normally open state.

[0122] In this embodiment, the brake member is charged not while the blade drive member is being charged but while the set is being released, thereby dispersing the peak load during drive and suppressing a decrease in the motor rotation speed. As a result, this embodiment can provide a shutter unit and an image capture device that can achieve both high continuous shooting speed and compactness.

[0123] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of the gist of the present invention. [Explanation of symbols]

[0124] 317 Rear curtain charge cam gear (charge member) 500 Rear drive lever unit (drive member) 511 Drive spring (biasing member) 630 Rear brake lever (braking member) 800 Shutter rear curtain (blade component) 910 Main plate 910a aperture 1000 focal plane shutter (shutter unit)

Claims

1. a base plate having an opening formed therein; at least one blade member; a driving member that is rotatably supported on the base plate and drives the blade member from a standby position to a travel completion position by the biasing force of a biasing member during photography; a braking member that contacts the driving member and decelerates the driving member; a charging member that moves the driving member from the travel completion position to a set position against the biasing force of the biasing member and then moves the driving member to the standby position, and that moves the braking member from the travel completion position to the standby position while the driving member is moving from the set position to the standby position; a motor for supplying a driving force to the charging member; a rotation speed detection means for detecting the rotation speed of the motor; a control unit; The control unit controls the motor so that the rotational speed of the motor detected by the rotational speed detection means becomes a predetermined rotational speed while the drive member is moving from the set position to the standby position, thereby keeping the rotational speed of the charge member constant and keeping the speed at which the drive member and the charge member are released from contact constant.

2. 2. The imaging device according to claim 1, wherein the standby position is a position where the blade members are able to travel.

3. the blade members have leading and trailing blade members that are movable between a blocking state in which they block the opening and a retracted state in which they retract from the opening, the driving member drives the rear blade member from the standby position to the travel completion position by the biasing force of the biasing member during photography; The imaging device according to claim 1, wherein the charging member operates the driving member from the travel completion position to the set position against the biasing force of the biasing member, and then operates the driving member to the standby position where the trailing blade member can travel, and operates the braking member from the travel completion position to the standby position while the driving member is operating from the set position to the standby position.

4. An imaging device as described in any one of claims 1 to 3, characterized in that it further comprises an imaging element that photoelectrically converts an optical image formed via an imaging optical system.

Images