Shutter device and image pickup apparatus

Abstract

A shutter device and a camera device. The shutter device includes: a base plate including an opening; a blade unit configured to switch the state of the opening; a drive member configured to drive the blade unit; a motor; a reducer configured to reduce the power from the motor; a first connector engaged with the reducer; a second connector attached at one end to the drive member and at the other end to the first connector; a first position detector configured to detect a predetermined position in a movement trajectory passing through the drive member or the first connector; and a second position detector configured to detect a relative difference with the first position detector. The blade unit switches the state of the opening from a closed state to an open state by continuous rotation of the first connector. The drive of the motor is controlled based on the detection results of the first and second position detectors.

Description

Technical Field

[0001] This disclosure relates to a shutter device and a camera device including the shutter device. Background Technology

[0002] Known existing shutter mechanisms are configured such that a drive spring is wound up by a driving force from a motor or the like, the wound state of the drive spring is maintained by an electromagnet or the like, and the force of the drive spring generated by the release of the maintained wound state causes the blades included in the shutter to move.

[0003] For example, Japanese Patent Application Publication No. 2019-61127 discusses a camera device that is configured to convert the driving force of a motor into the reciprocating motion of a drive rod by means of a lever-crank mechanism, and to wind up a drive spring by means of the reciprocating motion, thereby causing the blade to move. Summary of the Invention

[0004] According to an aspect of this disclosure, a shutter device includes: a base plate including an opening; a blade unit configured to switch the state of the opening between a closed state and an open state; a drive member attached to the blade unit and configured to drive the blade unit; a motor; a reducer configured to reduce the power from the motor; a first connector engaging with the reducer; a second connector attached at one end to the drive member and at the other end to the first connector; a first position detector configured to detect a predetermined position in a movement trajectory passing through the drive member or the first connector; and a second position detector configured to detect a relative difference with the first position detector, wherein the blade unit switches the state of the opening from the closed state to the open state by continuous rotation of the first connector in a first direction, and controls the drive of the motor based on the detection results of the first position detector and the second position detector.

[0005] Other features of this disclosure will become apparent from the following description of exemplary embodiments, with reference to the accompanying drawings. Attached Figure Description

[0006] Figure 1A and Figure 1B This is a diagram showing the blades and drive unit of a shutter device according to a first exemplary embodiment of the present disclosure.

[0007] Figure 2 This is a diagram illustrating the relationship between the angle of the crankshaft of the crank plate according to a first exemplary embodiment of the present disclosure and each phase of the blade's travel.

[0008] Figure 3 It is a graph showing the relative angular relationship between the crank plate and the main arm of the blade.

[0009] Figure 4 This is a diagram illustrating a shutter device comprising both a front curtain and a rear curtain according to a first exemplary embodiment of the present disclosure.

[0010] Figure 5A and Figure 5B This is an exploded perspective view of a shutter device according to a first exemplary embodiment of the present disclosure.

[0011] Figure 6 This is a partial perspective view of the drive mechanism of the blade unit according to a second exemplary embodiment of the present disclosure. Detailed Implementation

[0012] Preferred exemplary embodiments of the present disclosure are described in detail with reference to the accompanying drawings. Figure 1A and Figure 1B This is a diagram showing the blades and drive unit of the shutter device 50. Figure 2 It is a diagram showing the relationship between the angle of the crankshaft of the crank plate 15 and each phase of the blade's travel. Figure 3 It is a graph showing the relative angular relationship between the crank plate 15 and the main arm 2d of the blade. Figure 4 This is a diagram showing a shutter device that includes both a front curtain and a rear curtain. Figure 5A and Figure 5B This is an exploded perspective view of the shutter device 50. The shutter device 50 is arranged inside the imaging device 100 and can close and open the exposure opening (hereinafter simply referred to as the opening) 1a provided in the substrate 1 of the shutter device 50 to adjust the exposure state of the imaging device (not shown) provided in the imaging device 100. The shutter device 50 includes a substrate 1, a partition plate 6, a blade unit 2, a spacer 29, and a cover plate 8 arranged sequentially in the optical axis direction.

[0013] Reference Figures 1A to 5B This describes a shutter device 50 according to a first exemplary embodiment of the present disclosure.

[0014] The driving force of the motor 19 is transmitted to the crank plate 15 directly or through a gear system.

[0015] In this exemplary embodiment, the motor pinion 21 and the idler gear 17 (reducer) are located between the motor 19 and the crank plate 15. However, the motor 19 can directly drive the crank plate 15. The drive member 11 is a connector that is rotatably attached to the main arm 2d. A pin portion 11a located off-center from the rotation center and one end of the connecting rod 13 are rotatably attached to the connector 11. The other end of the connecting rod 13 is rotatably attached to the crankshaft 15a of the crank plate 15. The drive component that drives the blade unit 2 is positioned by the first retainer member and the second retainer member 10.

[0016] Figure 1A The image shows the unfolded state of blade unit 2. Figure 1B The blade unit 2 is shown in its folded (retracted) state. The drive member 11 performs a lever operation with these two states as its maximum displacement points. In this case, the drive member 11 reciprocates like a seesaw with the pin 11a connected to the connecting rod 13 as its point of action, thereby changing the state of the blade unit 2. The crank plate 15 is configured such that the positions of the crank shafts 15a corresponding to the aforementioned maximum displacement points of the drive member 11 are 180 degrees symmetrical to each other. In this exemplary embodiment, the above-described mechanism element is referred to as a lever-crank mechanism.

[0017] The shutter device 50 according to this exemplary embodiment does not include a drive spring and a suction retainer that can function as the main drive member in the blades traveling in conventional shutter devices. The drive member 11 is positioned in a predetermined position by the anti-backlash spring 4. However, the anti-backlash spring 4 does not apply a driving force to the drive member 11 for blade travel.

[0018] The shutter device 50 according to this exemplary embodiment includes a first position detector 23 and a second position detector 25. The first position detector 23 detects a point on the motion trajectory of the drive member 11, and the second position detector 25 can detect the movement angle (rotation angle) of the motor 19. In this respect, the shutter device 50 according to this exemplary embodiment differs from existing shutters.

[0019] In the shutter device 50, a reference position for driving the drive member 11 can be determined based on the detection result of the first position detector 23, and the amount of movement from the reference position can be determined based on the detection result of the second position detector 25. Figure 1A and Figure 1B As shown, it is desirable that the first position detector 23 be configured to avoid the vicinity of the two ends of the motion trajectory of the drive member 11. This is because, near the two ends, the change in the rotation angle of the drive member 11 is smaller relative to the change in the rotation angle of the crank plate 15, and a large error may occur in position detection due to slight displacement and deformation of the drive member 11 or the first position detector 23. Figure 5A The second position detector 25 shown emits a periodic pulse signal n times per revolution by means of, for example, a slotted disc 27 attached to the motor 19, and because the second position detector 25 is constructed as described above, it also functions as a speed detector. Due to the construction described above, the motor 19 is driven so that the slotted portion 2f of the blade unit 2 can move and can stop at an optional position.

[0020] The travel speed of the slit forming part 2f can be arbitrarily controlled by adjusting the output of the motor. When the control unit (e.g., a central processing unit (CPU) not shown) located inside the camera device 100 executes a predetermined program stored in a memory (not shown), the drive control of the shutter device 50 can be realized.

[0021] In the lever-crank mechanism, the blade unit 2 reciprocates once with each rotation of the crank plate 15. In other words, when the crank plate 15 rotates once, a series of operations are completed during exposure, from normal running (the blade travels to acquire the image) to return running (after normal running, the blade moves from a closed-open state to an open-open state). The positional relationship between the slit forming portion 2f and the crank shaft 15a of the crank plate 15 is shown in... Figure 1A In the middle. The slit-forming part 2f of the blade does not appear in the area at the opening 1a, which serves as the exposure opening, and can be used for acceleration and deceleration.

[0022] Regardless of the direction of rotation of crank plate 15, blade unit 2 can reciprocate. However, the relationship between the rotation angle of crank plate 15 and the rotation angle of the main arm 2d of blade unit 2 changes depending on the direction of rotation. This is because, for example, unlike the slider crank mechanism, the driven side (i.e., the blade unit 2 side) driven by the lever crank mechanism does not draw a linear track but an arc track.

[0023] Figure 3 This is a graph showing the rotational angle relationship between crank plate 15 and main boom 2d when crank plate 15 rotates. The solid line in the graph represents the rotation of crank plate 15 from... Figure 1A The diagram shows the movement trajectory cw of the main boom 2d when it rotates clockwise (cw). The dashed line in the graph represents the movement of the crank plate 15 from... Figure 1A The diagram shows the trajectory of the main boom 2d as it rotates counterclockwise (ccw). The dotted line in the graph represents an ideal cosine curve. When the crank plate 15 rotates continuously in one direction, the rotation direction of the main boom 2d periodically switches between the cw and ccw directions.

[0024] like Figure 3As shown, in the region where the rotation direction of the main arm 2d is the same as that of the crank plate 15, the main arm 2d traces a trajectory close to the ideal cosine curve. Conversely, when the rotation direction of the main arm 2d is opposite to that of the crank plate 15, the trajectory of the main arm 2d deviates significantly from the ideal cosine curve. In other words, as the blade travel curve, when the crank plate 15 rotates once, the trajectory alternates between being close to the ideal cosine curve and deviating significantly from the ideal cosine curve. The former trajectory is close to a straight line, and this trajectory is symmetrical between the first and second halves of the crank plate 15's rotation. Therefore, this trajectory is suitable for using the travel curve during the main exposure of the blade unit 2. Because this trajectory is close to a straight line, adjustments can be easily made if the motor is intentionally accelerated or decelerated to form the travel curve of the blade unit 2.

[0025] As described above, the control is preferably performed such that during exposure, the rotation direction of the main arm 2d is consistent with the rotation direction of the crank plate 15 during the blade travel of the blade unit 2. In other words, the region in which the rotation direction of the main arm 2d of the blade unit 2 is consistent with the rotation direction of the crank plate 15 is used as the blade travel region of the blade unit 2.

[0026] Motor pinion 21 and idler gear 17 are located between motor 19 and crank plate 15. However, motor pinion 21 and crank plate 15 can be driven by meshing with each other. In other words, any configuration can be used, as long as the power of motor 19 is reduced and transmitted to crank plate 15.

[0027] The power of motor 19 is reduced to decrease the load on motor 19 and improve the driving efficiency of motor 19. In the shutter device 50 according to this exemplary embodiment, the drive motor preferably has low inertia in order to accelerate quickly and obtain the necessary curtain speed. Generally, when the motor has low inertia, the motor torque is low, the driving efficiency may deteriorate, and the overall current consumption increases. Therefore, as described above, when the power of motor 19 is moderately reduced, the driving rate in the high-efficiency region can be increased, and the current consumption of motor 19 can be reduced.

[0028] Normally, the gear reduction ratio is set to an indivisible value to avoid repeated meshing of specific parts, resulting in uniform wear. However, in the shutter device 50 according to this exemplary embodiment, the reduction ratio is set to an integer multiple. Due to this configuration, the same starting angle of the motor 19 can be set at the beginning of each movement. Furthermore, from the start to the stop of movement, the gears mesh with each other at the same position. Therefore, in the shutter device 50 according to this exemplary embodiment, the movement of the blade unit 2 can be stabilized without changing the drive angle of the motor 19 and the meshing conditions of the drive gear used for each movement, and in this way, variations in curtain speed and exposure can be reduced. In the case where the motor pinion 21 and the crank plate 15 mesh directly with each other, and in the case where the idler gear 17 is between the motor pinion 21 and the crank plate 15, the gear reduction ratio is adjusted to an integer multiple.

[0029] (Shutter drive sequence)

[0030] The driving sequence of the shutter mechanism 50 is explained. To actually drive the blade unit 2, the current position of the slit forming part 2f needs to be known. As described above, the series of operations from normal travel to return travel during exposure and their phases are as follows: Figure 2 As shown. However, it is desirable to know the angle information in advance when the slit forming part 2f is in the main control target position. For example, the reference position O is obtained by the first position detector 23, and the relative angles such as the travel start position A, initial position B, end position C and stop limit position D are obtained in advance by the second position detector 25.

[0031] The travel start position A is the starting reference position when the travel of blade unit 2 begins during exposure. Therefore, the optimal starting range for achieving the predetermined travel speed (curtain speed) of blade unit 2 is set, and the travel start position A is set at... Figure 2 Within the acceleration range shown, so-called light leakage into opening 1a does not occur before the blade unit 2 travels. Note that the motor 19 according to this exemplary embodiment includes cogging torque, and the shaft angle of the motor that stops naturally by the cogging torque is consistent with the aforementioned travel start position A. The initial position B is the reference position for the start of exposure using the blade unit 2, and is set near the end (opening end) of the exposure start side of opening 1a (upstream side of the travel direction of blade unit 2). The end position C is the reference position for the end of exposure using the blade unit 2, and is set near the end (opening end) of the exposure end side of opening 1a (downstream side of the travel direction of blade unit 2). The stop limit position D is the stop limit position of the blade unit 2, and is set at... Figure 2The deceleration / stopping range shown is intended to prevent unnecessary exposure caused by removing the light shield of opening 1a again after the exposure has ended.

[0032] like Figure 2 As shown, the position corresponding to the slit forming portion 2f of the crank plate 15 corresponds to the curtain speed of the blade unit 2, which travels from the starting position A to the ending position C after the crank plate 15 passes the initial position B. It is desired that the curtain speed be controlled so that the travel speed of the blade unit 2 in the travel direction is constant and close to the target value (ideal value). As a method for controlling the curtain speed, adjusting the curve (called the travel curve) representing the relationship between the travel position and travel time of the blade is known. In this exemplary embodiment, a rotary encoder (not shown) is provided as a detector for detecting the rotation of the output shaft of the motor 19, and the rotational speed of the motor 19 and the displacement from the initial position can be determined.

[0033] In this exemplary embodiment, the ideal travel curve of the blade unit 2 is pre-recorded in the camera device 100, and the difference between this curve and the curve during normal travel of the blade unit 2 output from the rotary encoder is detected. Furthermore, the output of the motor 19 is adjusted to reduce this difference, so that the travel curve of the blade unit 2 can approach the ideal travel curve.

[0034] Returning to the starting position is the operation of moving the drive member from the stopped position back to the starting position. Normally, this requires reversing the rotation direction of the drive member by changing the rotation direction of a motor or similar device. However, in this exemplary embodiment, the crank plate 15 is rotated in the same direction as the normal travel direction during the return movement. Therefore, the crank plate 15 can return to the starting position A with a small amount of movement.

[0035] The return travel is an operation not directly related to the main exposure. Therefore, there is no need for high-precision control of the travel speed and return travel time of blade unit 2. Thus, for example, the output of motor 19 is reduced during the return travel to significantly reduce the current consumption of blade unit 2 per series of operations (one sequence).

[0036] For simplicity, the operation of a single blade unit 2 has been described. This scenario applies, for example, to a so-called electronic front curtain shutter drive that controls the front curtain via sensor reset (or readout). In the shutter device 50 described above, blade unit 2 can function as the front curtain, and blade unit 3 can function as the rear curtain, as... Figure 4As shown. In this case, the drive mechanism for each blade unit can operate independently. The blade units and drive mechanisms are arranged symmetrically, and each blade unit is controlled to perform operations based on the aforementioned mechanism. For example, the drive member and blade unit are arranged symmetrically about a line passing through the center of the opening 1a and parallel to the long side direction (longitudinal direction) of the opening 1a (i.e., the line that divides the opening 1a into an upper and lower part).

[0037] (LV continuous imaging sequence)

[0038] In order to perform the so-called live view display operation during continuous imaging (referred to as LV continuous imaging), it is necessary for the shutter device 50 to be prepared to open the opening 1a (LV phase) between two consecutive main exposures (normal travel) (between imaging frames). As described above, in the shutter device 50 according to this exemplary embodiment, two different blade units (front curtain and rear curtain) can be driven independently. Therefore, by performing the return travel of the blade unit on the rear curtain side after reading the imaging (image) data of a specific frame, the opening 1a can be opened. Furthermore, the slit forming portion 2f of the blade unit (on the rear curtain side) is immediately at the stop limit position D after imaging. Therefore, the opening 1a can be opened quickly simply by rotating the motor in the same direction to move the slit forming portion 2f to the travel start position A.

[0039] In order to switch to the travel standby state after the LV phase of the shutter device 50 ends, the blade unit 2 corresponding to the front curtain is returned from the stop limit position D to the travel start position A. By performing the above operation, both the blade units for the front curtain and the blade units for the rear curtain remain at the travel start position A, which allows for immediate transition to the next imaging frame.

[0040] (Status of the shutter mechanism during a power outage)

[0041] This describes the state of the shutter device 50 when the camera device 100 is powered off. When the camera device 100 is powered off, no power is supplied to the motor 19 of the shutter device 50.

[0042] The aforementioned lever-crank mechanism causes the drive member 11 to reciprocate by rotating the crank plate 15. Conversely, the crank plate 15 can be operated by applying force to the drive member 11. When the crank plate 15 is operated from a stationary position, the load required to operate it varies depending on the position of the drive member 11. For example, when the drive member 11 is positioned in the middle of the reciprocating track, a small load is required to operate the crank plate 15. Conversely, when the drive member 11 is near the top dead center or bottom dead center of the reciprocating motion, a large load is required to operate the crank plate 15. In other words, when the drive member 11 is near the top dead center or bottom dead center of the reciprocating motion, it is difficult for the drive member 11 to move unless force is applied from the crank plate 15 side. Due to these characteristics, even when the camera device 100 is powered off, the blade unit 2 can maintain the opening 1a in both an open and light-blocking (closed) state.

[0043] For example, in order to keep the opening 1a open when the camera device 100 is powered off, the motor 19 is driven in response to a power-off command of the camera device 100, and the camera device 100 is powered off after the blade unit 2 moves to the open position of the opening 1a. For example, in order to keep the opening 1a in a light-blocking state when the camera device 100 is powered off, the motor 19 is driven in response to a power-off command of the camera device 100, and the camera device 100 is powered off after the opening 1a is in a light-blocking state via the blade unit 2. With this configuration, the shutter device 50 according to this exemplary embodiment can easily maintain either a light-blocking state or an open state via the blade unit 2 when the camera device 100 is powered off.

[0044] As described above, since the shutter device 50 according to this exemplary embodiment employs a lever-crank mechanism, the loss of flexibility in adjusting the curtain speed and travel curve can be prevented without the need for a drive member such as a drive spring and another mechanism such as a blade adsorption holding mechanism.

[0045] A shutter device 60 according to a second exemplary embodiment of the present disclosure is described. The shutter device 60 differs from the shutter device 50 described in the first exemplary embodiment in that the shutter device 60 includes a limiting member 31. Otherwise, the shutter device 60 according to this exemplary embodiment has the same construction as the shutter device 50 according to the first exemplary embodiment, and the same names and reference numerals are used for these parts.

[0046] In this exemplary embodiment, in order to prevent light leakage before the blade unit 2 travels normally and unnecessary re-exposure after normal travel, the limiting member 31 restricts the movement of the crank plate 15 within a predetermined range. Figure 6This is a partial perspective view of the drive mechanism of the blade unit 2 according to a second exemplary embodiment of the present disclosure. Figure 6 As shown, the protrusion 31a of the limiting member 31 is arranged to abut against the protrusion 15b of the crank plate 15 in the rotational direction of the crank plate 15. The limiting member 31 is arranged such that the rotational phase of the crank plate 15 against which the protrusions 15b and 31a abut is in the same direction as... Figure 2 Within the range corresponding to the return travel. In other words, when protrusions 15b and 31a interfere with each other, the slit forming portion 2f is not located between the stop limit position D and the travel start position A, but the range for normal travel, acceleration, and deceleration can be ensured as in the first exemplary embodiment described above. With this configuration, light leakage and re-exposure caused by accidental rotation of the crank plate 15 can be prevented.

[0047] On the other hand, in this exemplary embodiment, unlike the first exemplary embodiment described above, a series of rotations from the normal travel of the blade unit 2 to its return travel cannot be completed by rotating the crank plate 15 in the same direction. More specifically, in the shutter device 60 according to this exemplary embodiment, after the normal travel of the blade unit 2, it is necessary to rotate the motor 19 in the opposite direction to the normal travel rotation direction to reverse the crank plate 15, thereby returning the crank plate 15 to the starting position A.

[0048] In the shutter device 60 according to this exemplary embodiment, the motor 19 and crank 15 need to be reversed during the return travel. Therefore, the return travel time is longer compared to the shutter device 50 according to the first exemplary embodiment described above. However, generally, the return travel of a shutter device does not require highly precise position control and can be performed with low motor output, and the time available to complete the operation is longer. Therefore, the impact on the imaging operation of the subject using the shutter device 60 is smaller. In other words, the shutter device 60 according to this exemplary embodiment can prevent the loss of flexibility in adjusting the curtain speed and travel curve, while preventing unnecessary exposure.

[0049] Regarding the maintenance of the state of the blade unit 2 when the camera device 100 is powered off, the shutter device 60 differs from the shutter device 50 in that the shutter device 60 can prevent the drive member 11 from moving due to external forces even when the drive member 11 is separated from its position near each dead point in the reciprocating motion. More specifically, in the shutter device 60, the motor 19 serves as a drive source that includes an iron core in the armature and includes cogging torque. Furthermore, a reducer such as the idler gear 17 is located between the motor 19 and the crank plate 15. As a result, in order to move the crank plate 15 away from the drive member 11 side, an increased speed is required, and a force obtained by multiplying the cogging torque of the motor 19 by the speed increase ratio is required. When the shutter device 60 has this configuration, compared to the shutter device 50 according to the first exemplary embodiment, even at positions offset from each dead point in the reciprocating motion of the drive member 11, the drive member 11 hardly moves due to external forces toward the drive member 11. For example, the movement of the drive member 11 due to external forces can be limited to a range from near the two dead points in the reciprocating motion of the drive member 11 to the position abutting against the limiting member 31. In other words, even when the positional accuracy associated with the control of the drive member is lower than that in the first exemplary embodiment, the shutter device 60 can maintain the open state and the closed state of the opening 1a as the state of the blade unit 2 when the camera device 100 is powered off.

[0050] While preferred exemplary embodiments of the present disclosure have been described above, the present disclosure is not limited to these exemplary embodiments, and various modifications and substitutions can be made within the spirit and scope of the present disclosure. For example, in each of the above exemplary embodiments, a configuration employing a lever-crank mechanism as a drive mechanism associated with the shutter device for adjusting the exposure in subject imaging is described. However, the configuration is not limited thereto.

[0051] For example, any of the shutter devices described above can be used as a light-shielding device that does not involve adjusting the exposure in the imaging of the subject. In this case, the shutter device described above can be used as a light-shielding device that protects the imaging sensor of the camera device 100 from sunlight and dust, while using the electronic shutter function to adjust the exposure in the imaging of the subject.

[0052] Other implementation methods

[0053] The embodiments of the present invention can also be implemented by providing software (programs) that perform the functions of the above embodiments to a system or device via a network or various storage media, and the computer or central processing unit (CPU) or microprocessor unit (MPU) of the system or device reading out and executing the program.

[0054] While this disclosure has been described with reference to exemplary embodiments, it should be understood that this disclosure is not limited to the disclosed exemplary embodiments. The scope of the appended claims should be accorded the broadest interpretation so as to cover all such variations and equivalent structures and functions.

Claims

1. A shutter device comprising: a substrate including an opening; a blade unit configured to switch a state of the opening between a closed state and an open state; a drive member attached to the blade unit and configured to drive the blade unit; a motor; a speed reducer configured to reduce power from the motor; a first connecting member engaged with the speed reducer; a second connecting member including a link rotatably attached at one end to the drive member and at the other end to the first connecting member; a first position detector configured to detect a predetermined position in a movement locus of the drive member or the first connecting member; and a second position detector configured to detect a relative difference from the first position detector, characterized in that the first connecting member is a crank that is rotatable, the second connecting member is an arm that moves on a predetermined locus by rotation of the first connecting member, the drive member reciprocates with movement of the second connecting member, the blade unit switches the state of the opening from the closed state to the open state by continuous rotation of the first connecting member in a first direction, and driving of the motor is controlled based on detection results of the first position detector and the second position detector. A reduction ratio of the speed reducer is an integer multiple.

2. The shutter device of claim 1, wherein, The blade unit switches the state of the opening from the closed state to the open state by continuous rotation of the first connecting member in the first direction and returns to the closed state again by normal travel at the time of imaging of a subject.

3. The shutter device of claim 1, wherein, The blade unit performs an operation of continuously imaging a subject only by continuous rotation of the first connecting member in the first direction.

4. The shutter device of claim 3, wherein, 5. The shutter device according to claim 3, further comprising a restriction member configured to restrict a rotation angle of the first connecting member, the restriction member restricts movement of the first connecting member in the first direction to switch the state of the opening from the closed state to the open state after normal travel of the blade unit. wherein The first position detector is arranged at a position different from a position near a stop point of reciprocation of the drive member.

6. The shutter device of claim 1, wherein, The second position detector detects a rotation angle of the motor.

7. The shutter device of claim 1, wherein, The motor includes cogging torque, and a shaft angle at which the cogging torque naturally stops coincides with a travel start position.

8. The shutter device of claim 1, wherein, 9. An image pickup apparatus comprising: the shutter device according to claim 1. ​

Images