JP2010008633A - Electromagnetic actuator and blade driving device for camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable a rotor to stop at a middle position other than both ends of an actuation range, while simplifying an electromagnetic actuator. <P>SOLUTION: The electromagnetic actuator is equipped with the rotor 40 turning within the predetermined actuation range, a coil for excitation 60, and a yoke 50 having a first magnetic pole part 51a and a second magnetic pole part 52a generating different magnetic poles from each other by energizing the coil, wherein the rotor 40 includes a magnetized rotor part 41 magnetized to have different magnetic poles in a circumferential direction, and a projecting part 42 projecting to a radial direction from an outer circumferential surface and magnetized to have the same magnetic pole as that of the outer circumferential surface, and the yoke 50 includes an auxiliary magnetic pole part 51b formed to extend from either the first magnetic pole part or the second magnetic pole part so as to be opposed to the projecting part in the radial direction of the rotor when the rotor is located at the middle position of the actuation range. Thus, the rotor can be stopped at three positions, that is, both end positions and the middle position of the actuation range, while achieving simplification of structure. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electromagnetic actuator that generates a driving force by rotating a predetermined operation range by an electromagnetic force, and in particular, includes a rotor that can be stopped at both end positions and halfway positions of an operation range, The present invention relates to an electromagnetic actuator applied when driving a blade member such as a filter blade, and a camera blade driving device using the same.

Conventional electromagnetic actuators mounted on camera shutter devices, etc., are magnetized with two poles (N-pole and S-pole) and are capable of reciprocating at a predetermined angle (operation range), facing the outer peripheral surface of the rotor A substantially U-shaped yoke having two magnetic pole portions arranged so as to have an excitation coil wound around the yoke, and the rotor is one rotating end (initial position) of the operating range when the current is not energized Rotate to the other rotation end (maximum rotation position) of the operating range when energized, return to one rotation end by reverse energization and stop, that is, both end positions (two positions) of the operating range Is formed so as to stop at (see, for example, Patent Document 1).
In this electromagnetic actuator, by providing a protrusion on the rotor, the rotational starting force from both end positions and the holding force (detent torque) at both end positions can be increased, but the rotor is positioned in the middle of the operating range. Can not be stopped.
Therefore, when this electromagnetic actuator is applied as a drive source for a diaphragm blade of a camera, for example, in order to stop the diaphragm blade at the diaphragm position, the rotor is rotated to an angular position in the middle of the operation range and mechanically stopped. Then, a complicated stop mechanism or the like is required, which leads to an increase in cost due to an increase in the number of parts, an increase in size of the apparatus, and the like.

In addition, as other electromagnetic actuators, a rotor magnetized with four poles (N pole, S pole, N pole, S pole), magnetic pole portions at both ends arranged to face the outer peripheral surface of the rotor, and intermediate A yoke having three magnetic pole parts composed of a magnetic pole part, a first coil for excitation wound around the yoke between the magnetic pole part at one end and the intermediate magnetic pole part, and between the magnetic pole part at the other end and the intermediate magnetic pole part A step including a second coil for excitation wound around a yoke, and the like, wherein the rotor can be stopped at a plurality of angular positions by performing two-phase excitation and one-phase excitation on the first coil and the second coil. A motor is known (see, for example, Patent Document 2).
In this electromagnetic actuator, although the rotor can be stopped at a plurality of angular positions, two coils are required, and energization control is complicated because two-phase excitation and one-phase excitation are performed. Incurs high costs.

JP 2006-288036 A Japanese Patent Laid-Open No. 2005-24802

  The present invention has been made in view of the above points, and the object of the present invention is to simplify the structure and reduce the cost without adopting a complicated stop mechanism or the like, and the rotor. It is an object of the present invention to provide an electromagnetic actuator that can be stopped at an intermediate position other than both end positions of an operating range, and a camera blade driving device using the electromagnetic actuator.

The electromagnetic actuator of the present invention defines a rotor that has a cylindrical outer peripheral surface and rotates within a predetermined operating range, an excitation coil, and an arcuate surface that faces the outer peripheral surface of the rotor. An electromagnetic actuator comprising a first magnetic pole portion and a yoke having a second magnetic pole portion that generate different magnetic poles, wherein the rotor defines an outer peripheral surface and is magnetized with different magnetic poles in the circumferential direction. A rotor portion and a protrusion portion that protrudes in a radial direction from the outer peripheral surface and is magnetized to the same magnetic pole as the outer peripheral surface, and the yoke is arranged in a radial direction of the rotor when the rotor is located in the middle of the operating range. And an auxiliary magnetic pole portion formed to extend from one of the first magnetic pole portion and the second magnetic pole portion so as to face the protruding portion.
According to this configuration, the coil is energized in a state where the rotor is positioned at one rotation end of the operating range, the rotor moves to a midway position, and the protruding portion faces the auxiliary magnetic pole portion, so that the coil is Even if it is de-energized, the rotor stops at its midway position, and if the coil is de-energized when the coil is energized and the rotor further rotates to reach the other rotation end of the operating range, The rotor stops at the other rotation end. In other words, by simply changing the rotor and yoke shapes without providing special parts, the rotor can be stopped at at least three positions, both at the middle and middle positions, while simplifying the structure and reducing costs. Can be made.

In the electromagnetic actuator having the above configuration, a configuration in which the intermediate position is an intermediate position of the operation range can be adopted.
According to this configuration, while simplifying the shape of the yoke, the rotor can be stopped at an intermediate position of the operating range (intermediate angle position of the operating angle) in a state where the protruding portion and the auxiliary magnetic pole portion face each other.

In the electromagnetic actuator having the above-described configuration, the protruding portion is formed so as to define an arc surface at the distal end in the radial direction, and the auxiliary magnetic pole portion is formed so as to define an arc surface facing the arc surface of the protruding portion. The configuration can be adopted.
According to this configuration, the magnetic attractive force and the magnetic repulsive force generated between the protrusion and the auxiliary magnetic pole can be efficiently applied while achieving simplification of the shape of the protrusion and the auxiliary magnetic pole. it can.

In the electromagnetic actuator having the above-described configuration, the magnetized rotor portion has an N pole outer peripheral surface and an S pole outer peripheral surface divided into two in the circumferential direction, and the projecting portion is one of the N pole outer peripheral surface and the S pole outer peripheral surface. The structure currently formed so that it may protrude from the approximate center of the circumferential direction is employable.
According to this configuration, the yoke (having the first magnetic pole portion, the second magnetic pole portion, and the auxiliary magnetic pole portion) can be formed in a simple contour shape so that the rotor is stopped at an intermediate position in the operating range. it can.

In the electromagnetic actuator having the above-described configuration, when the rotor is located at the intermediate position, the magnet is disposed so as to face the other of the N pole outer peripheral surface and the S pole outer peripheral surface on a straight line passing through the rotation center and the protrusion of the rotor. A configuration that further includes a member can be employed.
According to this configuration, when the rotor is located at the intermediate position, the projecting portion faces the auxiliary magnetic pole portion and generates a magnetic attractive force, and the magnetic member faces the outer peripheral surface of the rotor and generates a magnetic attractive force. The rotor can be reliably stopped at the intermediate position by the strong magnetic holding force.

In the electromagnetic actuator having the above-described configuration, the rotor can adopt a configuration including an output pin formed of a resin material so as to output a driving force to the outside.
According to this configuration, the drive target can be smoothly driven by connecting the output pin not affected by the magnetic force to the drive target such as a blade member of the camera.

In the electromagnetic actuator having the above-described configuration, the yoke integrally includes a first arm portion having a first magnetic pole portion and a second arm portion having a second magnetic pole portion and inserted into a bobbin around which a coil is wound. And the 2nd arm part can employ | adopt the structure currently formed in thickness thinner than the 1st arm part.
According to this configuration, since the second arm portion of the yoke inserted into the bobbin around which the coil is wound is formed thinner than the first arm portion, the second arm portion has the same thickness as the first arm portion. Compared with the case where it forms, the insertion hole of the bobbin in which a 2nd arm part is inserted can be made small, and the winding number of a coil can be increased by that much.

Further, the camera blade driving device of the present invention includes a substrate having an opening for exposure, a fully open position for fully opening the opening, a stop position for narrowing the opening to a predetermined aperture, and a fully closed for fully closing the opening. A blade member movably supported with respect to the substrate to be positioned at each position, and a drive source for driving the blade member, the drive source being any one of the electromagnetic actuators configured as described above It is characterized by that.
According to this configuration, since the electromagnetic actuator described above is employed as the drive source, the blade member is moved to the three positions of the fully open position, the throttle position, and the fully closed position while achieving simplification of the structure and cost reduction. It can be positioned by moving it to a position.

In the camera blade driving device having the above-described configuration, the blade members cooperate with each other to fully open the opening when positioned at the fully open position, and when the shutter member is positioned at the throttle position, the opening is throttled to a predetermined aperture and fully closed. It is possible to adopt a configuration including a first swing blade and a second swing blade formed so as to fully close the opening when positioned.
According to this configuration, the first oscillating blade and the second oscillating blade cooperate with each other to form the aperture / shutter blade that defines the fully open state, the aperture state, and the fully closed state. The structure can be simplified as compared with a configuration including two dedicated shutter blades for opening and closing and a dedicated diaphragm blade for narrowing the opening to a predetermined aperture.

  According to the electromagnetic actuator and the camera blade drive device having the above-described configuration, the rotor can be moved to a position other than the positions at both ends of the operating range while achieving a simplified structure and cost reduction without employing a complicated stop mechanism or the like. It can also be stopped at an intermediate position, and by driving, for example, a diaphragm blade member using this electromagnetic actuator, it is possible not only to open and close the opening but also to a predetermined aperture.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
1 to 9 show an embodiment in which an electromagnetic actuator according to the present invention is applied to a camera blade drive device. FIG. 1 is a plan view of the camera blade drive device, and FIG. 2 is a camera blade drive device. FIG. 3 is a plan view of the electromagnetic actuator, FIG. 4 is a plan view showing a blade member included in the camera blade driving device, and FIGS. 5 and 6 explain the operation of the electromagnetic actuator. FIG. 7 is a plan view showing a state in which the blade member is in a fully open position for fully opening the opening, FIG. 8 is a plan view showing a state in which the blade member is in a throttle position for narrowing the opening to a predetermined aperture, and FIG. FIG. 5 is a plan view showing a state in which the blade member is in a fully closed position where the opening is fully closed.

  As shown in FIGS. 1 to 4, the camera blade driving device includes a base plate 10 and a back plate 20 as substrates having openings 10 a and 20 a for exposure, and a blade member supported by the base plate 10 in a swingable manner. 30 and an electromagnetic actuator M as a drive source for driving the blade member 30.

As shown in FIGS. 1, 2, and 4, the base plate 10 includes a circular exposure opening 10 a, a support shaft 11 that rotatably supports a rotor 40 that will be described later, a substantially fan-shaped through hole 12, and a description that will be described later. The connecting portion 13 in which a screw hole for screwing the screw B for fixing the presser plate 70 is formed, the support shafts 14 and 15 for rotatably supporting the blade member 30, and the screw B for fixing the back plate 20 are screwed together. And a fully-opened stopper 17 for stopping the blade member 30 at the fully-open position, a fully-closed stopper 18 for stopping the blade member 30 at the fully-closed position, and the like.
As shown in FIGS. 2 and 4, the back plate 20 has a circular opening 20a for exposure, an arc-shaped long hole 21 for exposing an output pin 43 of the rotor 40 described later, a circular hole 22 and the like. And is connected to the back side end face of the base plate 10 with a screw B at a predetermined interval, and demarcates a vane chamber W in which the vane member 30 is rotatably accommodated.

As shown in FIGS. 2 and 4, the blade member 30 is swingably supported by the first swing blade 31 that is swingably supported by the support shaft 14 of the base plate 10 and the support shaft 15 of the base plate 10. The second swing blade 32 is used.
As shown in FIG. 4, the first oscillating blade 31 is larger than a circular hole 31a through which the support shaft 14 passes, a long hole 31b into which an output pin 43 of the rotor 40 described later is inserted, and the openings 10a and 20a. A circular large opening 31c having an inner diameter, a semicircular opening 31d having a predetermined inner diameter smaller than the openings 10a and 20a formed continuously to the large opening 31c, and the like are provided.
As shown in FIG. 4, the second swing blade 32 cooperates with a circular hole 32a through which the support shaft 15 is passed, a long hole 32b into which an output pin 43 of the rotor 40 described later is inserted, and a semicircular opening 31d. And a semicircular opening 32d having a predetermined inner diameter formed so as to define a circular opening having a predetermined aperture smaller than the openings 10a and 20a.

The first oscillating blade 31 and the second oscillating blade 32 are retracted from the openings 10a and 20a in cooperation with each other when a rotor 40 (to be described later) rotates within a predetermined operating range θ and fully opened. And a fully-closed position in which a part of the openings 10a and 20a faces to a predetermined aperture and a fully closed position in which the openings 10a and 20a are fully closed.
That is, the first oscillating blade 31 and the second oscillating blade 32 cooperate with each other to fully open the openings 10a and 20a when positioned at the fully open position and open the openings 10a and 20a when positioned at the throttle position. The apertures 10a and 20a are fully closed when the aperture is limited to a predetermined diameter and is located at the fully closed position.

  As shown in FIGS. 1 to 3, the electromagnetic actuator M is formed by winding a rotor 40 that is rotatably supported by the base plate 10, a yoke 50 formed in a substantially U shape, an exciting coil 60, and a coil 60. It is formed by a presser plate 70 provided integrally with a bobbin 71.

As shown in FIGS. 2 and 3, the rotor 40 defines a cylindrical outer peripheral surface and is magnetized with a magnetized rotor portion 41 magnetized with different magnetic poles (N pole, S pole) in the circumferential direction. An output pin 43 that protrudes in the radial direction and is joined to the lower side of the magnetized rotor portion 41 with the projecting portion 42 magnetized to the same magnetic pole as the outer peripheral surface thereof and outputs a driving force to the outside (that is, the blade member 30). Etc.
2 and 3, the magnetized rotor portion 41 is divided into two halves in the circumferential direction with a boundary surface passing through the through hole 41 a through which the support shaft 11 passes and the rotation center L as a boundary, and is magnetized to different magnetic poles. The N pole outer peripheral surface 41b and the S pole outer peripheral surface 41c are defined.

As shown in FIG. 3, the protruding portion 42 is formed on the S pole outer peripheral surface 41 c so as to protrude from the approximate center in the circumferential direction toward the radially outer side, and has the same magnetic pole (S pole) as the S pole outer peripheral surface 41 c. ) Is magnetized. Further, the projecting portion 42 is formed so as to taper outward in the radial direction and define a circular arc surface 42a having a predetermined curvature radius at the distal end in the radial direction.
The arc surface 42a of the projecting portion 42 is an arc surface of an auxiliary magnetic pole portion 51b of the yoke 50 described later in the radial direction of the rotor 40 when the rotor 40 is located at an intermediate position P _m (intermediate position) of the operating range θ. 51b ').
Thus, since the arc surface 42a of the protruding portion 42 and the arc surface 51b 'of the auxiliary magnetic pole portion 51b described below are opposed to each other, the shapes of the protruding portion 42 and the auxiliary magnetic pole portion 51b are simplified. On the other hand, the magnetic attractive force and the magnetic repulsive force generated between the protruding portion 42 and the auxiliary magnetic pole portion 51b can be efficiently applied.

As shown in FIGS. 2 and 3, the output pin 43 is formed by using a non-magnetized material such as a resin material so as to extend in the radial direction of the rotor 40 and extend in the direction of the rotation center L. The first swing blade 31 is inserted into the long hole 31b and the second swing blade 32 is inserted into the long hole 32b. Thus, by forming the output pin 43 from a resin material that is not affected by the magnetic force, the blade member 30 that is a drive target can be smoothly driven.
Then, the rotor 40, as shown in FIG. 3, between the end position P ₁ and the other end position P ₂ of the operating range θ to reciprocate, and intermediate position P _m is in the middle position of the operating range θ Is supported by the support shaft 11 of the main plate 10.

As shown in FIGS. 2 and 3, the yoke 50 is formed to be bent in a substantially U shape so as to define the first arm portion 51 and the second arm portion 52 and to define a circular hole 53 in the bent region. Has been.
The yoke 50 is formed as a first arc part 51a defining an arcuate surface 51a 'on the distal end side of the first arm part 51, and an arc formed by extending further from the first magnetic pole part 51a on the distal end side of the first arm part 51. An auxiliary magnetic pole part 51b that defines a surface 51b 'and a second magnetic pole part 52a that defines an arcuate surface 52a' on the distal end side of the second arm part 52 are provided.
The first magnetic pole part 51 a (arc surface 51 a ′) and the second magnetic pole part 52 a (arc surface 52 a ′) are formed point-symmetrically with respect to the rotation center L of the rotor 40. Further, the arc surface 51a ′ of the first magnetic pole portion 51a and the arc surface 52a ′ of the second magnetic pole portion 52a are formed to face the N pole outer peripheral surface 41b and the S pole outer peripheral surface 41c of the rotor 40 with a predetermined gap. Thus, a magnetic attractive force and a repulsive force are generated between the rotor 40 (the magnetized rotor portion 41).
The arc surface 51 b ′ of the auxiliary magnetic pole portion 51 b is formed so as to face the arc surface 42 a of the protrusion 42 with a predetermined gap in the radial direction of the rotor 40. And repulsive force is generated.

The coil 60 is wound around the bobbin 71 of the presser plate 70 as shown in FIGS.
As shown in FIGS. 1 and 2, the presser plate 70 is formed in a substantially flat plate shape so as to press the yoke 60 against the base plate 10, a bobbin 71 around which the coil 60 is wound, and a circular hole 72 through which the screw B is passed. Etc. The bobbin 71 defines an insertion hole 71 a into which the second arm portion 52 of the yoke 50 is inserted.
The presser plate 70 is joined to the base plate 10 and fixed by screws B in a state where the coil 60 is wound around the bobbin 71 in advance and the yoke 50 (second arm portion 52 thereof) is inserted into the insertion hole 71a. The rotor 40 mounted on the support shaft 11 is restricted from falling off, the yoke 60 is fixed at a predetermined position, and the coil 60 is held at a predetermined position.

Here, the operation of the electromagnetic actuator M will be described with reference to FIGS. 5 and 6.
First, the coil 60 is not energized, the rotor 40, for example, as shown in FIG. 5 (a), located at the end position P _1. At this time, the first magnetic pole portion 51a attracts the N pole outer peripheral surface 41b clockwise, the second magnetic pole portion 52a attracts the S pole outer peripheral surface 41c clockwise, and the magnetic biasing force clockwise against the rotor 40 together. Effect. Thus, the rotor 40 is (here, the full open stopper 17 via the output pin 43 and the blade member 30) by a stopper clockwise rotation is restricted, it is positioned and held to one end position P _1.

  In this state, when the coil 60 is energized in a predetermined direction, as shown in FIG. 5B, N poles are generated in the first magnetic pole part 51a and the auxiliary magnetic pole part 51b, and S poles are generated in the second magnetic pole part 52a. Occurs. Thus, the first magnetic pole part 51a and the second magnetic pole part 52a generate a repulsive force so as to rotate the rotor 40 counterclockwise, and the rotor 40 starts to rotate counterclockwise. A magnetic attraction force is generated between the auxiliary magnetic pole portion 51b and the protruding portion 42, and this magnetic attraction force acts to assist the counterclockwise rotation of the rotor 40.

Then, as shown in FIG. 5 (c), when the rotor 40 is cut off the energization of the intermediate position (or immediately before) at which point P _m coil 60 of the operating range theta, as shown in FIG. 5 (d) The magnetic poles (N pole and S pole) generated in the first magnetic pole part 51a, the auxiliary magnetic pole part 51b, and the second magnetic pole part 52a disappear, and the protruding part 42 of the rotor 40 and the auxiliary magnetic pole part 51b attract each other. As a result, a magnetic attractive force is generated. Thus, the rotor 40 is positioned and held stopped at the intermediate position P _m.

Subsequently, as shown in FIG. 6 (a), from a state where the rotor 40 is stopped at the intermediate position P _m, the coil 60 again is energized in the same direction, as shown in FIG. 6 (b), the An N pole is generated in the first magnetic pole part 51a and the auxiliary magnetic pole part 51b, and an S pole is generated in the second magnetic pole part 52a. As a result, the first magnetic pole portion 51a generates an attractive force with the S pole outer peripheral surface 41c and generates a repulsive force with the N pole outer peripheral surface 41b, and the second magnetic pole portion 52a has a contact with the N pole outer peripheral surface 41b. A suction force is generated between them, and a repulsive force is generated between the S pole outer peripheral surface 41c and the rotor 40 starts to further rotate counterclockwise. The auxiliary magnetic pole portion 51b generates an attractive force with the protrusion 42, but is smaller than the magnetic attractive force generated between the first magnetic pole portion 51a and the second magnetic pole portion 52a and the rotor 40. It does not affect the clockwise rotation.

Then, as shown in FIG. 6 (c), the cut off energization of the coil 60 when the rotor 40 reaches the other end position P ₂ operating range theta, as shown in FIG. 6 (d), the first magnetic pole The magnetic poles (N pole and S pole) generated in the part 51a, the auxiliary magnetic pole part 51b, and the second magnetic pole part 52a disappear. The first magnetic pole portion 51a attracts the S pole outer peripheral surface 41c counterclockwise, and the second magnetic pole portion 52a attracts the N pole outer peripheral surface 41b counterclockwise. Energize. Thus, the rotor 40 is the stopper (here, the output pin 43 and the blade member 30 full-close stopper 18 via a) with counterclockwise rotation is restricted, is positioned and held at the other end position P _2.

On the other hand, when the coil 60 is energized in the reverse direction, an S pole is generated in the first magnetic pole part 51a and the auxiliary magnetic pole part 51b, and an N pole is generated in the second magnetic pole part 52a, so that the rotor 40 rotates clockwise. and, through the intermediate position P _m from the other end position P ₂ moves to one end position P _1, by energization of the coil 60 is cut off, it is positioned and held to one end position P _1.

As described above, the rotor 40 is provided with the protrusion 42 and the yoke 50 with the auxiliary magnetic pole portion 51b. The operation range θ can be stopped at three positions: one end position (one end position P ₁ , the other end position P ₂ ) and an intermediate position P _m as an intermediate position.

Next, the operation of the camera blade drive apparatus using the electromagnetic actuator M as a drive source will be described with reference to FIGS.
First, in the standby state, the rotor 40 is stopped at the initial position (one end position P ₁ ). At this time, as shown in FIG. 7, the output pin 43 positions the first oscillating blade 31 and the second oscillating blade 32 in the fully open position via the long holes 31b and 32b. In this fully open state, the first swing blade 31 and the second swing blade 32 are in contact with the fully open stopper 17 and are positioned at the fully open position.

In this state, when it is determined that the control unit performs the diaphragm based on the light amount sensor or the like, the control unit performs pulse energization for the coil 60 with a relatively short energization time. As a result, the rotor 40 rotates counterclockwise, reaches the intermediate position _Pm , and stops. At this time, as the output pin 43 moves counterclockwise, as shown in FIG. 8, the first swing blade 31 and the second swing blade 32 partially stop toward the openings 10a and 20a. The semicircular openings 31d and 32d cooperate with each other to define a circular opening having a predetermined diameter, and the openings 10a and 20a are narrowed to a predetermined diameter. This throttled state is held only by the magnetic holding force (attraction force) generated between the protruding portion 42 of the rotor 40 and the auxiliary magnetic pole portion 51b of the yoke 50 after the power supply to the coil 60 is cut off.

Subsequently, when the release operation is performed, the control unit performs pulse energization on the coil 60 in the same direction with a relatively long energization time. Thereby, the rotor 40 further rotates counterclockwise, reaches the maximum rotation position (the other end position P ₂ ), and stops. At this time, as the output pin 43 moves counterclockwise, as shown in FIG. 9, the first swing blade 31 and the second swing blade 32 move to the fully closed position facing the openings 10a and 20a. As a result, the openings 10a and 20a are fully closed. In this fully closed state, the first swing blade 31 and the second swing blade 32 abut against the fully closed stopper 18 and are positioned at the fully closed position.
As described above, the closing operation of the blade member 30 (the first swing blade 31 and the second swing blade 31) completes one shooting with the camera including the image sensor.

Thereafter, by performing a relatively long pulse energization current time in the opposite direction to the control unit is a coil 60, rotor 40, from the maximum rotation position (the other end position P ₂₎ shown in FIG. 9, the intermediate position P _m , Pass back to the initial position (one end position P ₁ ) and stop. With this operation, the blade member 30 (the first swing blade 31 and the second swing blade 32) moves to the fully open position as shown in FIG. 7, and waits for the next photographing.

When the control unit determines that the diaphragm is not to be throttled, the rotor 40 is moved from the initial position (one end position P ₁ ) shown in FIG. 7 to the state shown in FIG. It rotates quickly to the maximum rotation position shown (other end position P ₂ ). At this time, the first swing blade 31 and the second swing blade 32 move from the fully open position shown in FIG. 7 to the fully closed position shown in FIG. 9, and one photographing is completed.

As described above, when causing the diaphragm operation by moving the blade member 30 (first swinging vane 31 and the second swing blades 32), to stop the rotor 40 to the intermediate position P _m simply urging force magnetically This eliminates the need for a mechanical stop mechanism and simplifies the device. As a result, downsizing, cost reduction, weight reduction, and the like of the device can be achieved.

10 to 17 show another embodiment in which the electromagnetic actuator according to the present invention is applied to a camera blade drive device. FIG. 10 is a plan view of the camera blade drive device, and FIG. 11 is a camera blade. FIG. 12 is a plan view of the electromagnetic actuator, FIGS. 13 and 14 are plan views for explaining the operation of the electromagnetic actuator, and FIG. 15 is a fully open position where the blade member fully opens the opening. FIG. 16 is a plan view showing a state in which the blade member is in a throttle position that restricts the opening to a predetermined aperture, and FIG. 17 shows a state in which the blade member is in a fully closed position that fully closes the opening. It is a top view.
In this embodiment, except that the magnetic member 80 is included in the electromagnetic actuator M ′, this embodiment is basically the same as the above-described embodiment. Therefore, the same components are denoted by the same reference numerals and description thereof is omitted. To do.

In this embodiment, as shown in FIGS. 10 to 12, the electromagnetic actuator M ′ includes a rotor 40 rotatably supported by the base plate 10, a yoke 50 formed in a substantially U shape, and an excitation coil 60. The presser plate 70 and the magnetic member 80 are provided integrally with a bobbin 71 around which the coil 60 is wound.
The magnetic member 80 is formed in a cylindrical shape, as shown in FIG. 12, when the rotor 40 is positioned at the intermediate position P _m operating range theta, straight through the center of rotation L and the protruding portion 42 of the rotor 40 SL Above, it arrange | positions so that the N pole outer peripheral surface 41b of the rotor 40 may be opposed, and is being fixed to the ground plane 10 as shown in FIG.

Here, the operation of the electromagnetic actuator M ′ will be described with reference to FIGS. 13 and 14.
First, the coil 60 is not energized, the rotor 40, for example, as shown in FIG. 13 (a), located at the end position _{P 1.} At this time, the first magnetic pole portion 51a attracts the N pole outer peripheral surface 41b clockwise, the second magnetic pole portion 52a attracts the S pole outer peripheral surface 41c clockwise, and the magnetic biasing force clockwise against the rotor 40 together. Effect. The magnetic member 80 generates a magnetic attractive force with the N pole outer peripheral surface 41b, but is smaller than the clockwise magnetic biasing force. Thus, the rotor 40 is (here, the full open stopper 17 via the output pin 43 and the blade member 30) by a stopper clockwise rotation is restricted, it is positioned and held to one end position P _1.

  In this state, when the coil 60 is energized in a predetermined direction, as shown in FIG. 13B, N poles are generated in the first magnetic pole part 51a and the auxiliary magnetic pole part 51b, and S poles are generated in the second magnetic pole part 52a. Will occur. Thereby, the first magnetic pole part 51a and the second magnetic pole part 52a generate a repulsive force so as to rotate the rotor 40 counterclockwise, and the magnetic attraction between the magnetic member 80 and the N pole outer peripheral surface 41b. With the addition of force, the rotor 40 begins to rotate counterclockwise. A magnetic attraction force is generated between the auxiliary magnetic pole portion 51b and the protruding portion 42, and this magnetic attraction force acts to assist the counterclockwise rotation of the rotor 40.

Then, as shown in FIG. 13 (c), when the rotor 40 is cut off the energization of the intermediate position (or immediately before) at which point P _m coil 60 of the operating range theta, as shown in FIG. 13 (d) The magnetic poles (N pole and S pole) generated in the first magnetic pole part 51a, the auxiliary magnetic pole part 51b, and the second magnetic pole part 52a disappear, and the protruding part 42 of the rotor 40 and the auxiliary magnetic pole part 51b attract each other. As a result, a magnetic attractive force is generated. Further, the magnetic member 80 and the N pole outer peripheral surface 41b of the rotor 40 generate a magnetic attractive force so as to attract each other. Thus, the rotor 40 is the larger magnetic coercivity than the embodiments described above, is positioned and held stopped at the intermediate position P _m.

Subsequently, as shown in FIG. 14 (a), from a state where the rotor 40 is stopped at the intermediate position P _m, the coil 60 again is energized in the same direction, as shown in FIG. 14 (b), the An N pole is generated in the first magnetic pole part 51a and the auxiliary magnetic pole part 51b, and an S pole is generated in the second magnetic pole part 52a. As a result, the first magnetic pole portion 51a generates an attractive force with the S pole outer peripheral surface 41c and generates a repulsive force with the N pole outer peripheral surface 41b, and the second magnetic pole portion 52a has a contact with the N pole outer peripheral surface 41b. A suction force is generated between them, and a repulsive force is generated between the S pole outer peripheral surface 41c and the rotor 40 starts to further rotate counterclockwise. At this time, the magnetic attractive force generated between the auxiliary magnetic pole portion 51b and the protruding portion 42 and the magnetic attractive force generated between the magnetic member 80 and the N pole outer peripheral surface 41b are the first magnetic pole portion 51a and the first magnetic pole portion 51b. The magnetic attraction force generated between the two magnetic pole portions 52a and the rotor 40 is small and does not affect the counterclockwise rotation of the rotor 40.

Then, as shown in FIG. 14 (c), the cut off energization of the coil 60 when the rotor 40 reaches the other end position P ₂ operating range theta, as shown in FIG. 14 (d), the first magnetic pole The magnetic poles (N pole and S pole) generated in the part 51a, the auxiliary magnetic pole part 51b, and the second magnetic pole part 52a disappear. The first magnetic pole portion 51a attracts the S pole outer peripheral surface 41c counterclockwise, and the second magnetic pole portion 52a attracts the N pole outer peripheral surface 41b counterclockwise. Energize. Thus, the rotor 40 is the stopper (here, the output pin 43 and the blade member 30 full-close stopper 18 via a) with counterclockwise rotation is restricted, is positioned and held at the other end position P _2.

On the other hand, when the coil 60 is energized in the reverse direction, an S pole is generated in the first magnetic pole part 51a and the auxiliary magnetic pole part 51b, and an N pole is generated in the second magnetic pole part 52a, so that the rotor 40 rotates clockwise. and, through the intermediate position P _m from the other end position P ₂ moves to one end position P _1, by energization of the coil 60 is cut off, it is positioned and held to one end position P _1.

Thus, the projecting portion 42 provided in the rotor 40, an auxiliary magnetic pole portion 51b provided in the yoke 50, further magnetic member 80 for generating effective magnetic holding force when the rotor 40 is positioned at the intermediate position P _m By adopting the rotor 40, the rotor 40 is positioned at both ends (one end position P ₁ and the other end position P ₂ ) of the operating range θ and on the way while achieving simplification of the structure and cost reduction without providing any special parts. it can be stopped at three positions on the intermediate position P _m as a position.

  The operation of the camera blade drive device using this electromagnetic actuator M ′ as a drive source is the same as that of the above-described embodiment except that the magnetic acting force of the magnetic member 80 is applied, and the electromagnetic actuator M ′. Accordingly, the blade member 30 (the first swing blade 31 and the second swing blade 32) is moved from the fully open position shown in FIG. 15 to the throttle position shown in FIG. 16 and the fully closed position shown in FIG. Thus, the camera is stopped and positioned at each position, and the photographing operation from the aperture state or the photographing operation from the state where the aperture is not performed is performed.

Thus, when to perform the stop operation by moving the blade member 30 (first swinging vane 31 and the second swing blades 32), stopping the rotor 40 in an intermediate position P _m simply urging force magnetically Therefore, similarly to the above-described embodiment, a mechanical stop mechanism is not necessary, and the apparatus is simplified. As a result, downsizing, cost reduction, weight reduction, and the like of the device can be achieved.

FIG. 18 shows still another embodiment of the electromagnetic actuator according to the present invention, which is the same as the above-described embodiment except that the yoke and the presser plate are partially changed. About the same structure, the same code | symbol is attached | subjected and description is abbreviate | omitted.
That is, in this embodiment, the yoke 50 'includes a first arm part 51 having a first magnetic pole part 51a and an auxiliary magnetic pole part 51b, a second arm part 52' having a second magnetic pole part 52a, a circular hole 53, and a step part. 54 '.
The second arm portion 52 ′ is formed to be thinner than the first arm portion 51 with the stepped portion 54 ′ as a boundary.
Therefore, the insertion hole 71a ′ of the bobbin 71 ′ in the presser plate 70 into which the second arm portion 52 ′ is inserted is formed smaller than the insertion hole 71a of the above-described embodiment.
According to this, the number of turns of the coil 60 can be increased by the amount that the insertion hole 71a ′ of the bobbin 71 ′ into which the second arm portion 52 ′ is inserted can be reduced.
When the number of turns of the coil 60 is the same, the bobbin 71 ′ can be thinned in the direction of the rotation axis (rotation center L) of the rotor 40, so that the electromagnetic actuator can be thinned.

In the above-described embodiment, the auxiliary magnetic pole part 51b that faces the protruding part 42 of the rotor 40 is provided in the first arm part 51 that can generate the same magnetic pole as the first magnetic pole part 51a. However, as long as it can be inserted into the bobbin 71, an auxiliary magnetic pole portion may be provided on the second arm portions 52 and 52 '.
In the said embodiment, although the thing which consists of the 1st rocking | fluctuation blade 31 and the 2nd rocking | fluctuation blade 32 was shown as the blade member 30, it is not limited to this, As a blade member, two or three One diaphragm blade that defines the diaphragm opening may be employed, or ND filter blades having different concentrations may be employed in two or three stages.
In the above embodiment, the case where the intermediate position _Pm is adopted as the position where the rotor 40 stops other than the both end positions of the operating range θ is shown, but the present invention is not limited to this, and other intermediate positions are adopted. May be.
In the above embodiment, the case where the base plate 10 is provided with the fully open stopper 17 and the fully closed stopper 18 in order to stop the blade member 30 at the fully open position and the fully closed position is shown, but it is not limited thereto. The functions of the fully open stopper and the fully closed stopper can be obtained by bringing the output pins 43 into contact with both end portions of the inner edge of the through hole 12 of the base plate 10.

  As described above, according to the electromagnetic actuator of the present invention, the rotor can be moved to a position other than the both end positions of the operating range while achieving a simplified structure and cost reduction without employing a complicated stop mechanism or the like. Since it can also be stopped at the position, it can be applied as a drive source for driving a blade member that also serves as an aperture of a camera, and is also useful as a drive source for driving other drive targets.

It is a top view which shows one Embodiment of the blade drive device for cameras provided with the electromagnetic actuator which concerns on this invention. FIG. 2 is a developed cross-sectional view showing a part of the camera blade driving device shown in FIG. It is a top view which shows the electromagnetic actuator contained in the blade drive device for cameras shown in FIG. It is a top view which shows the blade | wing member, ground plate, etc. which are contained in the blade drive device for cameras shown in FIG. FIG. 2 is a diagram for explaining the operation of an electromagnetic actuator included in the camera blade driving device shown in FIG. 1, and (a) to (d) show the position of the rotor and the magnetic pole state of the yoke when the coil is energized and de-energized. It is a state diagram. FIG. 2 is a diagram for explaining the operation of an electromagnetic actuator included in the camera blade driving device shown in FIG. 1, and (a) to (d) show the position of the rotor and the magnetic pole state of the yoke when the coil is energized and de-energized. It is a state diagram. FIG. 2 is a plan view showing a state in which the blade member is in a fully opened position where an opening is fully opened in the camera blade driving device shown in FIG. 1. FIG. 2 is a plan view showing a state in which the blade member is in an aperture position where an opening is narrowed to a predetermined aperture in the camera blade drive device shown in FIG. 1. FIG. 2 is a plan view showing a state where the blade member is in a fully closed position in which the opening is fully closed in the camera blade driving device shown in FIG. 1. It is a top view which shows other embodiment of the blade drive device for cameras provided with the electromagnetic actuator which concerns on this invention. It is an expanded sectional view which shows a part of blade drive device for cameras shown in FIG. It is a top view which shows the electromagnetic actuator contained in the blade drive device for cameras shown in FIG. FIG. 10 illustrates the operation of an electromagnetic actuator included in the camera blade driving device shown in FIG. 10, and (a) to (d) show the position of the rotor and the magnetic pole state of the yoke when the coil is energized and de-energized. It is a state diagram. FIG. 10 illustrates the operation of an electromagnetic actuator included in the camera blade driving device shown in FIG. 10, and (a) to (d) show the position of the rotor and the magnetic pole state of the yoke when the coil is energized and de-energized. It is a state diagram. FIG. 11 is a plan view showing a state where the blade member is in a fully open position where the opening is fully opened in the camera blade driving device shown in FIG. 10. FIG. 11 is a plan view showing a state in which the blade member is in an aperture position that restricts the opening to a predetermined aperture in the camera blade driving device shown in FIG. 10. FIG. 11 is a plan view showing a state where the blade member is in a fully closed position in which the opening is fully closed in the camera blade driving device shown in FIG. 10. FIG. 5 shows still another embodiment of the electromagnetic actuator according to the present invention, wherein (a) is a plan view showing a part thereof, and (b) a side view showing a part thereof.

Explanation of symbols

10 Ground plane (substrate)
10a Opening 11 for exposure 11 Support shaft 12 Through hole 13 Connection portion 14, 15 Support shaft 16 Connection portion 17 Fully open stopper 18 Fully closed stopper 20 Back plate (substrate)
20a Opening for exposure 21 Long hole 22 Circular hole 30 Blade member 31 First rocking blade 31a Circular hole 31b Long hole 31c Large opening 31d Semicircular opening 32 Second rocking blade 32a Circular hole 32b Long hole 32d Semicircular opening M, M 'Electromagnetic actuator 40 Rotor 41 Magnetized rotor portion 41a Through hole 41b N pole outer peripheral surface 41c S pole outer peripheral surface 42 Protruding portion 42a Arc surface 43 Output pin 50, 50' Yoke 51 First arm 51a First magnetic pole 51a 'Arc surface 51b Auxiliary magnetic pole portion 51b' Arc surfaces 52, 52 'Second arm portion 52a Second magnetic pole portion 52a' Arc surface 53 Circular hole 54 'Stepped portion 60 Coil B Screw 70 Press plate 71, 71' Bobbin 71a, 71a ′ Insertion hole 72 Circular hole 80 Magnetic member L Rotation center SL A straight line passing through the rotation center and the protrusion of the rotor θ Operating range P of the rotor ₁ One end position (initial rotation position)
_Pm middle position (midway position)
P ₂ other end position (maximum rotation position)

Claims (9)

A rotor having a cylindrical outer peripheral surface that rotates within a predetermined operating range, an exciting coil, and an arc surface opposed to the outer peripheral surface of the rotor, and different magnetic poles are generated by energizing the coil. An electromagnetic actuator comprising a yoke having a first magnetic pole part and a second magnetic pole part,
The rotor demarcated the outer circumferential surface and magnetized with different magnetic poles in the circumferential direction, and the rotor protruded in the radial direction from the outer circumferential surface and magnetized to the same magnetic pole as the outer circumferential surface Including protrusions,
The yoke is formed to extend from one of the first magnetic pole part and the second magnetic pole part so as to face the protruding part in the radial direction of the rotor when the rotor is located in the middle of the operating range. Including the auxiliary magnetic pole,
An electromagnetic actuator characterized by that. The intermediate position is an intermediate position of the operating range.
The electromagnetic actuator according to claim 1. The protrusion is formed to define a circular arc surface at a radial tip,
The auxiliary magnetic pole part is formed so as to delimit an arc surface opposite to the arc surface of the protrusion,
The electromagnetic actuator according to claim 1, wherein the electromagnetic actuator is characterized in that The magnetized rotor portion has an N pole outer peripheral surface and an S pole outer peripheral surface divided into two in the circumferential direction,
The protruding portion is formed so as to protrude from a substantially center in the circumferential direction on one of the N pole outer peripheral surface and the S pole outer peripheral surface.
The electromagnetic actuator according to claim 2 or 3, characterized in that. A magnetic member disposed so as to face the other of the N pole outer peripheral surface and the S pole outer peripheral surface on a straight line passing through the rotation center of the rotor and the protruding portion when the rotor is located at the intermediate position; Including,
The electromagnetic actuator according to claim 4. The rotor includes an output pin formed of a resin material in order to output a driving force to the outside.
An electromagnetic actuator according to any one of claims 1 to 5, wherein The yoke integrally includes a first arm portion having the first magnetic pole portion and a second arm portion having the second magnetic pole portion and inserted into a bobbin around which the coil is wound,
The second arm portion is formed to be thinner than the first arm portion.
The electromagnetic actuator according to any one of claims 1 to 6, characterized in that: A substrate having an opening for exposure, a fully open position for fully opening the opening, a stop position for narrowing the opening to a predetermined aperture, and a fully closed position for fully closing the opening, respectively. A wing member supported movably with respect to the wing member, and a drive source for driving the wing member,
The drive source is an electromagnetic actuator according to any one of claims 1 to 7,
A blade drive device for a camera. The blade members cooperate with each other to fully open the opening when positioned at the fully open position, and when the blade member is positioned at the throttle position, the opening is throttled to a predetermined aperture and positioned at the fully closed position. The first swing blade and the second swing blade formed so as to fully close the opening,
The camera blade drive device according to claim 8.

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