JP2001142111A - Electromagnetic actuator, shutter device and diaphragm device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnetic actuator suitable as a drive source of a shutter device having both of a shutter mechanism and a diaphragm mechanism and a diaphragm device whose diaphragm diameter can be controlled in multistage. SOLUTION: This electromagnetic actuator 2 is provided with a rotor 2a which is constituted of a permanent magnet and which can be bidirectionally turned between one end position and the other end position across an intermediate position, a coil 8 wound round the circumference of the rotor 2a so as to turn the rotor 2a according as it is energized, and a self holding means for holding the rotor 2a at the intermediate position, one end position or the other end position in a non-energizing state in which the coil 8 is not energized. Then, the self holding means is provided with an elastic member 5 regulating the rotor 2a at the intermediate position by mechanical elastic force, one magnetic member 6 facing the rotor being the permanent magnet and holding the rotor 2a at one end position by magnetic attraction force and the other magnetic member 6 facing the permanent magnet and holding the rotor 2a at the other end position by the magnetic attraction force.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shutter device and a diaphragm device incorporated in a digital camera or the like.
Further, the present invention relates to an electromagnetic actuator used as a drive source of a shutter device and a diaphragm device.

[0002]

2. Description of the Related Art When photographing a subject using a camera, there is a case where it is desired to optimize a combination of a lens aperture and a shutter speed according to the situation. Conventionally, as such a camera, there has been a method in which a diaphragm mechanism for defining the aperture of a lens opening and a shutter mechanism for opening and closing the lens opening are separately provided and individually controlled. In such a diaphragm mechanism, the aperture of the lens aperture is generally defined in two stages.

[0003]

However, an electromagnetic actuator is required for driving the aperture mechanism and the shutter mechanism, respectively, and there are great restrictions in terms of cost and space efficiency. As for the aperture mechanism, a method capable of setting the aperture in more stages is desired.

[0004] In view of such problems of the prior art, an object of the present invention is to provide a shutter device having both a shutter mechanism and an aperture mechanism. It is another object of the present invention to provide a diaphragm device capable of controlling the diaphragm diameter in more stages. It is another object of the present invention to provide an electromagnetic actuator suitable as a drive source for these shutter devices and aperture devices.

[0005]

The following means have been taken in order to achieve the above-mentioned object of the present invention. That is, an electromagnetic actuator according to the present invention includes a rotor made of a permanent magnet and rotatable bidirectionally between one end position and the other end position with an intermediate position interposed therebetween, and wound around the rotor to respond to energization. And a self-holding means for holding the rotor at an intermediate position, one end position, or the other end position in a non-energized state in which the coil is not energized. The self-holding means is an elastic member that regulates the rotor to an intermediate position by mechanical elastic force, and one magnetic member that faces the permanent magnet and holds the rotor at one end position by magnetic attraction.
And the other magnetic member facing the permanent magnet and holding the rotor at the other end position by magnetic attraction. Specifically, when the rotor comes to the intermediate position, the elastic force exceeds the suction force and is regulated to the intermediate position, and when it comes to the one end position, the suction force overcomes the elastic force and the one end position At the other end position, the suction force overcomes the elastic force and is held at the other end position. Further, the coil requires a larger amount of current when driving the rotor from the intermediate position to one end position or the other end position than when driving the rotor from one end position or the other end position to the intermediate position.

The present invention also provides a shutter blade disposed on a base plate having a lens opening for opening and closing the lens opening.
An electromagnetic actuator connected to the shutter blades and driving the shutter blades to open and close, the electromagnetic actuator being a permanent magnet rotor capable of bidirectional rotation between one end position and the other end position across an intermediate position. And a coil wound around the rotor to rotate the rotor in response to energization, and three points of an intermediate position, one end position, and the other end position of the rotor in a non-energized state where the coil is not energized. And a self-holding means for selectively holding the rotor, the self-holding means includes an elastic member for regulating the rotor to an intermediate position by mechanical elastic force, and a magnetic member facing the permanent magnet. One magnetic member that holds the rotor at one end position with an appropriate attractive force, and the other magnetic member that faces the permanent magnet and holds the rotor at the other end position with a magnetic attractive force. , The self-protection According to the three points of the rotor that can be held by the means, it is possible to shift to three points of a fully open position for opening the lens opening, a fully closed position for closing the lens opening, and a half open position for partially opening the lens opening. It is characterized by the following. In one aspect, the shutter blade is located at a fully open position corresponding to one end position of the rotor, is located at a fully closed position corresponding to an intermediate position of the rotor, and is at a half open position corresponding to the other end position of the rotor. Is placed. In another aspect, the shutter blade is located at a fully open position corresponding to one end position of the rotor, at a half open position corresponding to an intermediate position of the rotor, and at a fully closed position corresponding to the other end position of the rotor. To be placed.

Further, the present invention comprises an aperture blade disposed on a base plate having a lens aperture for regulating the aperture of the lens aperture, and an electromagnetic actuator connected to and driving the aperture blade. Is a rotor made of a permanent magnet rotatable bidirectionally between one end position and the other end position with an intermediate position interposed therebetween, and a coil wound around the rotor and rotating the rotor in response to energization. When the coil is not energized, the rotor is at an intermediate position,
And a self-holding means for selectively holding at three points at one end position and the other end position, wherein the self-holding means is an elastic member for regulating the rotor to an intermediate position by mechanical elastic force. And one magnetic member facing the permanent magnet and holding the rotor at one end position by magnetic attraction, and the other magnetic member facing the permanent magnet and holding the rotor at the other end position by magnetic attraction. The aperture blade can be set at three points that regulate the aperture of the lens opening differently from large, medium, and small in accordance with three points of the rotor that can be held by the self-holding means. Features.

An electromagnetic actuator according to the present invention is a moving magnet motor comprising a permanent magnet rotor and a coil wound therearound. By combining the suction force, the rotor can be self-held at three points: the intermediate position, the one end position, and the other end position. Here, the self-holding means that the rotor is held at a predetermined position in a non-energized state in which energization to the coil is cut off. The shutter device according to the present invention uses the electromagnetic actuator capable of self-holding at the three points described above as a drive source. The shutter blades are connected to this electromagnetic actuator, and can move to three points of a fully open position, a fully closed position, and a half open position corresponding to the three points of self-holding. In particular, the half-open position corresponds to the small aperture state, and the shutter device has both a shutter mechanism and an aperture mechanism. The aperture device according to the present invention uses the above-described electromagnetic actuator as a drive source. The aperture blade is connected to this electromagnetic actuator, and the aperture can be set in three stages, large, medium and small, corresponding to the three points of the rotor that can be held by itself.

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic partial sectional view showing a first embodiment of the shutter device according to the present invention.
As shown in the figure, the shutter device basically includes a pair of shutter blades 3 and 4 and an electromagnetic actuator 2 for driving the shutter blades. The shutter blades 3 and 4 are arranged on a base plate 1 having a lens opening (not shown), and are driven by an electromagnetic actuator 2 to open and close the lens opening. In the present embodiment, one of the shutter blades 3 rotates about a pin 3 b planted on the main plate 1. The other shutter blade 4
Rotates about a pin 4b similarly implanted in the main plate 1. The pair of shutter blades 3 and 4 are a base plate 1 and a blade holder 1.
and v is stored in a blade chamber provided between them.

The electromagnetic actuator 2 is mounted on the base plate 1 via a support 1u, and is connected to the shutter blades 3 and 4 to open and close them. The electromagnetic actuator 2 is a so-called moving magnet motor type, and has a rotor 2a made of a permanent magnet and a
and a coil 8 for rotating a. The rotor 2a has a rotation shaft 1b, and can rotate bidirectionally between one end position and the other end position with the intermediate position interposed therebetween. An operation angle range is between the one end position and the other end position. An operating pin 2b is integrally attached to the rotor 2a by resin molding, and engages with the above-mentioned shutter blades 3 and 4 to drive them. The coil 8 is wound around a coil frame 8a,
The rotor 2a is rotated bidirectionally within the operating angle range according to the energization. A yoke 7 is attached to the outer periphery of the coil frame 8a.

As a feature of the present invention, the electromagnetic actuator 2 has a self-holding means for holding the rotor 2a at the intermediate position, one end position or the other end position in a state where the coil 8 is not energized. . More specifically, the self-holding means holds the rotor 2a at one end position by means of an elastic member 5 for regulating the rotor 2a to an intermediate position by mechanical elastic force and a magnetic attractive force facing the rotor permanent magnet. It has one magnetic member 6 and the other magnetic member 6 facing the rotor permanent magnet and holding the rotor 2a at the other end position by magnetic attraction. In the case of this embodiment, the elastic member 5 is a pair of open ends 5.
It consists of a coil spring having i and 5j and is attached to a fixing pin 1c formed on the blade retainer 1v. A guide pin 1a similarly inserted in the blade retainer 1v is inserted between the pair of open ends 5i and 5j. The operating pin 2b integrally formed with the rotor 2a is connected to both open ends 5 of the elastic member 5.
i, 5j and is regulated to an intermediate position. According to the three points of the rotor 2a that can be held by the above-described self-holding means, the shutter blades 3 and 4 have a fully open position for opening the lens opening, a fully closed position for closing the lens opening, and a half open position for partially opening the lens opening. It is possible to shift to three points.

As described above, in the present embodiment, at the starting point (one end position) and the ending point (the other end position) of the operating angle range of the moving magnet motor, the attractive force is applied between the permanent magnets constituting the rotor 2a. And a resilient member 5 for holding the operating pin 2b of the rotor 2a at an intermediate position of the operating angle. At the beginning and end of the operating angle of the moving magnet motor, the rotor 2
The self-holding is performed by the attractive force between the permanent magnet (magnet) and the magnetic body 6 that constitutes a, and the position can be held by the elastic force of the elastic member 5 at the intermediate position of the operating angle. In addition, the magnet can be rotated from the initial point to the intermediate point by energizing the outer coil 8 to the magnet. In order to stop the rotation at the intermediate position, the energization time or the applied voltage may be controlled and the braking energization (brake energization) may be performed.

FIG. 2 is a schematic plan view of the shutter device shown in FIG. 1 as viewed from below the base plate (shutter blade side). The state shown is the rotor 2a of the electromagnetic actuator 2.
Is located at an intermediate position, and a pair of shutter blades 3 and 4 connected to the operating pin 2b are located at a fully closed position for closing a lens opening 1o formed on the main plate. Permanent magnet rotor 2a
Has an operating pin 2b integrated with resin. The operating pin 2b is engaged with operating long grooves 3a and 4a formed in the pair of shutter blades 3 and 4, respectively. This allows
The shutter blades 3 and 4 are rotatable around a rotation pin planted on the main plate. Elastic member 5 is provided on the main plate.
And a guide pin 1a for holding the state of the elastic member 5 are provided. Thereby, both open ends 5i and 5j of the elastic member 5 are connected to the operating pins 2 of the rotor 2a.
b. Electromagnetic actuator 2 shown
Is composed of a rotor 2a, a coil 8 and a yoke 7. By conducting the current in both forward and reverse directions to the coil 8, the rotor 2a can be rotated clockwise and counterclockwise within a predetermined operating angle range.

FIG. 3 is a schematic plan view of the shutter device shown in FIG. 1 as viewed from above the main plate (motor side). As in FIG. 2, the rotor 2a is held at an intermediate position, and a pair of shutters is provided. The blades 3, 4 are set to the fully closed position. As shown, the coil frame 8a around which the coil 8 is wound has a 90 ° angle.
Four grooves are provided at intervals, and four magnetic bodies 6a and 6 which generate magnetic attraction between the rotor and the rotor magnet.
b, 6c and 6d are attached. When the rotor 2a, which is a bipolar magnetized permanent magnet, arrives at the intermediate position, the elastic force of the elastic member overcomes the attraction of the magnetic members 6a to 6d and is regulated to the intermediate position as shown.

In the state shown in FIG. 2 and FIG.
In the non-energized state where no current is applied to the rotor, the attracting forces of the rotor magnet and the four magnetic members 6a to 6d cancel each other, while the holding force of the elastic member 5 keeps the rotor 2a stationary at the intermediate position.

FIGS. 4 and 5 show a state in which the rotor is held at one end position. FIG. 4 is a plan view as viewed from the shutter blade side, and FIG. 5 is a plan view as viewed from the motor side. As shown in the drawing, when the rotor 2a is held at the extreme end position on the counterclockwise direction in the drawing, the shutter blades 3 and 4 connected thereto are set to the fully opened position where the lens opening 1o is opened. When the rotor 2a comes to one end position, the magnetic members 6a, 6
The suction force of d overcomes the elastic force of the elastic member 5 and is held at one end position. The coil 8 needs a relatively large amount of current when driving the rotor 2a from the intermediate position to the one end position. Conversely, the coil 8 requires a relatively small amount of current when driving the rotor 2a from one end position to the intermediate position.

As shown in FIG. 4, when power is supplied to the S pole downward from the shutter blade side in the downward direction on the paper, the rotor 2 is driven by electromagnetic force.
a rotates counterclockwise, and the operating pin 2b is attached to the coil frame 8a.
Stops when hits. Even if the energization is interrupted in this state, the attractive force of the rotor magnet and the magnetic members 6a and 6d exceeds the elastic force of the elastic member 5, and is held in this state. Next, when the coil 8 is energized in the reverse direction, the rotor 2a rotates clockwise. At this time, it is possible to stop at the intermediate position shown in FIG. 2 by controlling the energization time and performing braking energization (brake energization) or voltage control so as not to go too far. As described above, the rotor 2a is self-held even when the power supply is interrupted at the intermediate position.

6 and 7 show a state in which the rotor 2a is held at the other end position. FIG. 6 is a plan view seen from the shutter blade side, and FIG. 7 is a plan view seen from the motor side. . When the rotor 2a is held at the other end position, the pair of shutter blades 3, 4 connected to the operating pin 2b is placed at a half-open position that partially blocks the lens opening 1o. At this time, the shutter blade 3 comes into contact with the pin 3t planted on the base plate, and the shutter blade 4 also contacts the pin 4t planted on the base plate.
Abut. An opening 3o is formed in the shutter blade 3, and an opening 4o is also formed in the shutter blade 4.
In the illustrated half-open position, these openings 3o and 4o overlap each other exactly at the center of the lens opening 1o, and are in a small aperture state. When the rotor 2a comes to the other end position, the magnetic material 6
The suction force by b and 6c exceeds the elastic force by the elastic member 5 and is held as it is. The coil 8 requires a larger amount of current to drive the rotor 2a from the intermediate position to the other end position than to drive the rotor 2a from the other end position to the intermediate position. When the coil 8 is energized in the reverse direction from the state held at the intermediate position, the rotor 2a
To be able to rotate clockwise overcoming the elastic force. After rotating clockwise by the electromagnetic force, the rotor 2a hits a stopper formed on the coil frame 8a and stops. Also in this case, even if power supply is interrupted by the attraction force between the rotor magnet and the magnetic bodies 6b and 6c, it can be held at the other end position shown in the figure. Further, in order to return from the other end position to the intermediate position, it is possible to return to the original state by performing the energization time by performing the energization in the forward direction and performing the energization by the braking. As is apparent from the above description, in the present embodiment, the shutter blades 3 and 4 are located at the fully open position corresponding to one end position of the rotor 2a, and are located at the fully closed position corresponding to the intermediate position of the rotor 2a. , The rotor 2a is placed at a half-open position (small throttle state) corresponding to the other end position.

When the shutter device according to the first embodiment shown in FIGS. 1 to 7 is used in a normal silver halide still camera, the shutter blades 3, 4 are first set to the fully closed position prior to the exposure operation. I do. That is, the motor is held at the intermediate position. Thereafter, the aperture is selected based on the luminance information of the subject.
That is, the fully open state or the half open state is selected. According to the selection result, the coil 8 is energized in the forward or reverse direction, and the motor is rotated to one end side in the counterclockwise direction or the other end side in the clockwise direction. To the middle position. As a result, the shutter blades 3, 4 return from the fully open position or the half open position to the first fully closed position.

When the shutter device according to the first embodiment shown in FIGS. 1 to 7 is used in a digital still camera, the shutter blades 3, 4 are set in advance to a fully open position or a half open position in a through state according to the luminance of the subject. deep. That is, the coil 8 is energized in advance to move the motor to one end position or the other end position, where it is held by itself. Then, when the release switch is turned on, the coil is energized to return the shutter blades 3 and 4 from the fully open position or the half open position to the fully closed position.

As is clear from the above description, in the first embodiment, in the three non-energized states, the intermediate position (middle point) of the motor corresponds to the fully closed position of the shutter blade, and the one end position (start point) is set. The other end position (end point) is made to correspond to the half-open position, corresponding to the fully open position. In this case, in the digital still camera, in order to operate the shutter blades from the fully open position or the half open position to the fully closed position, if the current supplied to the motor is increased, the digital still camera may operate from the start point to the end point without stopping at the middle point. Conceivable. In order to prevent this, relatively complicated electric control needs to be performed. Further, when switching between the fully open state and the half open state in accordance with the luminance of the subject in the through state, it is necessary to pass through the fully closed position once, and the control becomes relatively complicated. In view of the above, in the second embodiment described below, the shutter blade is located at the fully open position corresponding to one end position of the rotor,
The rotor is set at the half-open position corresponding to the intermediate position of the rotor, and is set at the fully closed position corresponding to the other end position of the rotor. That is, the middle point of the operation of the motor is set to the middle aperture when the shutter blades are half open. The start point and the end point are set to a fully open state and a fully closed state, respectively. Since the shutter blades are fully opened at the start point of the motor and half-open at the middle point, the maximum current allowed by the rating can flow from each state to the fully closed state, shortening the shutter blade closing time. it can. Further, the fully open position and the half open position can be set continuously even in the through state. Therefore, in either case, the control is simpler than in the first embodiment.

Hereinafter, with reference to FIGS. 8, 9 and 10,
The second embodiment outlined above will be described in detail. FIG.
FIG. 5 is a schematic plan view of the shutter device according to the second embodiment as viewed from the shutter blade side, and a rotor 2 a is held at an intermediate position (middle point) by an elastic member 5. At this time,
A pair of shutter blades 3, 4 connected to the operating pin 2b of the rotor 2a partially overlap on the lens opening 1o, and are placed in a half-open state (middle aperture state). FIG. 9 is a schematic plan view of the state in which the rotor 2a is held at one end position (start point) as viewed from the shutter blade side. As in the first embodiment, the rotor 2a is held at one end in a non-energized state by the action of a magnetic member (not shown) mounted on the coil frame. At this time, the pair of shutter blades 3 and 4 are retracted to both sides from the lens opening 1o, and are set in a fully opened state. FIG. 10 is a schematic plan view of the state where the rotor 2a is held at the other end position (end point) as viewed from the shutter blade side. The pair of shutter blades 3, 4 engaged with the operation pin 2b of the rotor 2a completely overlap on the lens opening 1o, and are in a fully closed state.

Next, the operation of the second embodiment will be described. When incorporated in a digital still camera, a large current is applied to the motor coil 8 in the forward direction from the middle stop at the middle point to the fully closed state at the end point. Conversely, in order to return from the middle throttle at the middle point to the fully open state at the start point, reverse current is applied with a relatively large current.
In order to return from the fully open state at the start point to the half open state (middle throttle state) at the middle point, reverse conduction is performed with a relatively small current. When the vehicle is driven from the fully open position at the start point to the fully closed position at the end point, it is only necessary to conduct the forward direction with a relatively large current.

FIGS. 11 to 13 show an embodiment of the aperture device according to the present invention. Parts corresponding to those of the embodiment of the shutter device described above are denoted by corresponding reference numerals for easy understanding. I have to. FIG. 11 is a schematic plan view of the present aperture device as viewed from below the main plate (the aperture blade side).
The rotor 2a is held at an intermediate position by the elastic member 5. At this time, the pair of aperture blades 30, 40 connected to the operating pin 2b of the rotor 2a regulates the diameter of the lens opening 1o. Specifically, an opening 31 formed in one aperture blade 30 and an opening 41 formed in the other aperture blade 40
However, they just overlap on the lens opening 1o, and regulate a predetermined aperture. FIG. 12 shows a state in which the rotor 2a is held at one end position. The attraction force of a magnetic body (not shown) mounted on the coil frame exceeds the elastic force of the elastic member 5, and the rotor 2a is held at one end. Self-hold in position.
At this time, the pair of diaphragm blades 30, 40 connected to the operating pin 2b of the rotor 2a are retracted to both sides from the lens opening 1o, and the maximum aperture is obtained. FIG. 13 shows the reverse of the rotor 2a.
Represents a state in which the self-holding is at the other end position. A pair of diaphragm blades 30, 40 connected to the operating pin 2b partially overlap the lens aperture 1o to define an intermediate aperture. Specifically, the opening 32 formed in the diaphragm blade 30 and the opening 42 formed in the diaphragm blade 40 overlap on the lens opening 1o, and the distance between the maximum diameter shown in FIG. 12 and the minimum diameter shown in FIG. The middle caliber is set.
In this manner, the pair of aperture blades 30 and 40 adjust the diameter of the lens opening 1o according to the three points (intermediate position, one end position and the other end position) of the rotor that can be held by the self-holding means provided on the electromagnetic actuator 2. It can be set to three points that are regulated differently from large, medium and small.

[0025]

As described above, according to the present invention,
By utilizing the elastic force of the elastic member and the attraction force of the magnetic material, the electromagnetic actuator can be self-held at three points. If this is incorporated in a shutter device, a camera shutter having two apertures can be realized. . or,
When this electromagnetic actuator is incorporated in a diaphragm device, it is possible to obtain three stages of diaphragm states with one actuator.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view showing a first embodiment of a shutter device according to the present invention.

FIG. 2 is a plan view of the shutter device according to the first embodiment.

FIG. 3 is a plan view of the first embodiment.

FIG. 4 is a plan view of the first embodiment.

FIG. 5 is a plan view of the first embodiment.

FIG. 6 is a plan view of the first embodiment.

FIG. 7 is a plan view of the first embodiment.

FIG. 8 is a plan view showing a second embodiment of the shutter device according to the present invention.

FIG. 9 is a plan view of the second embodiment.

FIG. 10 is a plan view of the second embodiment.

FIG. 11 is a plan view showing an embodiment of a diaphragm device according to the present invention.

FIG. 12 is a plan view of the diaphragm device.

FIG. 13 is a plan view of the diaphragm device.

[Explanation of symbols]

1 ... ground plate, 2 ... electromagnetic actuator, 2a ...
-Rotor, 2b-operating pin, 3-shutter blade, 4-shutter blade, 5-elastic member, 6-
-Magnetic member, 7 ... yoke, 8 ... coil, 8a
..Coil frame, 30 ... aperture blade, 40 ... aperture blade

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H080 AA19 AA61 AA64 AA67 AA72 2H081 AA51 BB17 BB22 CC25 CC27 CC32 DD01 5H633 BB08 BB15 BB16 GG02 GG15 HH03 HH07 HH10 HH13 JA02

Claims (7)

[Claims] 1. A rotor comprising a permanent magnet, which is rotatable bidirectionally between one end position and the other end position with an intermediate position interposed therebetween; and a rotor wound around the rotor and energized to energize the rotor. A rotating coil, and self-holding means for holding the rotor at an intermediate position, one end position, or the other end position in a non-energized state in which the coil is not energized; An elastic member that regulates the rotor to an intermediate position with mechanical elasticity, one magnetic member that faces the permanent magnet and holds the rotor at one end position by magnetic attraction, and a magnetic attraction that faces the permanent magnet. And a magnetic member for holding the rotor at the other end position by force. 2. When the rotor reaches an intermediate position, the elastic force overcomes the suction force and is restricted to the intermediate position. When the rotor reaches one end position, the attractive force overcomes the elastic force and the rotor moves to the one end position. 2. The electromagnetic actuator according to claim 1, wherein the suction force overcomes the elastic force and is held at the other end position when the other end position is reached. 3. The current supply amount required when driving the rotor from the intermediate position to one end position or the other end position is greater than the current supply amount required when driving the rotor from one end position or the other end position to the intermediate position. The electromagnetic actuator according to claim 1, wherein is larger. 4. A shutter blade disposed on a base plate having a lens opening for opening and closing the lens opening, and an electromagnetic actuator connected to the shutter blade for driving the shutter blade to open and close, wherein the electromagnetic actuator is located at an intermediate position. A rotor made of a permanent magnet rotatable bidirectionally between one end position and the other end position, a coil wound around the rotor to rotate the rotor in accordance with energization, and the coil A self-holding means for selectively holding the rotor at three points of an intermediate position, one end position, and the other end position in a non-energized state where power is not supplied to the shutter device. An elastic member that regulates the rotor to an intermediate position by mechanical elastic force, one magnetic member that faces the permanent magnet and holds the rotor at one end position by magnetic attraction, and a magnetic member that faces the permanent magnet and What The other magnetic member for holding the rotor at the other end position by attractive force, wherein the shutter blades open the lens opening in accordance with three points of the rotor that can be held by the self-holding means, A shutter device capable of shifting to three points: a fully closed position for closing a lens opening and a half-open position for partially opening the lens opening. 5. The shutter blade is located at a fully open position corresponding to one end position of the rotor, at a fully closed position corresponding to an intermediate position of the rotor, and a half open position corresponding to the other end position of the rotor. 5. The shutter device according to claim 4, wherein the shutter device is disposed. 6. The shutter blade is located at a fully open position corresponding to one end position of the rotor, at a half open position corresponding to an intermediate position of the rotor, and at a fully closed position corresponding to the other end position of the rotor. 5. The shutter device according to claim 4, wherein the shutter device is disposed. 7. A diaphragm blade disposed on a ground plate having a lens opening and regulating the aperture of the lens opening, and an electromagnetic actuator connected to and driving the diaphragm blade, wherein the electromagnetic actuator has an intermediate position. A rotor made of a permanent magnet rotatable bidirectionally between one end position and the other end position across a position, a coil wound around the rotor and rotating the rotor in accordance with energization, A self-holding means for selectively holding the rotor at three positions of an intermediate position, one end position, and the other end position in a non-energized state in which the coil is not energized; An elastic member that regulates the rotor to an intermediate position by mechanical elastic force, one magnetic member that faces the permanent magnet and holds the rotor at one end position by magnetic attraction, and a magnetic member that faces the permanent magnet. With attractive suction force The diaphragm blade has a diameter different from large, medium and small according to three points of the rotor which can be held by the self-holding means. A diaphragm device that can be set at three points that are regulated to a predetermined value.