JP2007159377A - Electromagnetic actuator and blade drive for camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To miniaturize an electromagnetic actuator mounted to a portable telephone, or the like, and to obtain strong holding power and driving force. <P>SOLUTION: There are provided: a rotor 41 that has an outer-periphery surface and can be rotated in a prescribed angle range; a coil 43 for excitation; first and second magnetic pole sections 42a, 42b that have circular arc surfaces opposite to the outer-periphery surface of the rotor 41 and generate mutually different magnetic poles by energization to the coil. The rotor 41 includes a radial magnetization section 41a that demarcates the outer-periphery surface and is magnetized to a magnetic pole different circumferentially, and a thrust magnetization section 41b that is integrated with the radial magnetization section 41a and is magnetized to the same magnetic pole for formation so that the thrust magnetization section 41b opposes the first and second magnetic pole sections 42a, 42b in the direction of an axis L. In this manner, the thrust magnetization section 41b is provided as the magnetization section of the rotor except the radial magnetization section 41a, thus increasing the holding power and driving torque. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electromagnetic actuator that generates a driving force by an electromagnetic force, and in particular, includes a rotor having a magnetized outer peripheral surface, a yoke that forms a magnetic pole portion facing the outer peripheral surface of the rotor, and the like, a shutter blade of a camera, The present invention relates to an electromagnetic actuator applied when driving a blade member such as a diaphragm blade and a blade driving device for a camera using the electromagnetic actuator.

As a conventional electromagnetic actuator mounted on a shutter device of a camera or the like, it is rotatably supported with respect to a substrate having an opening for exposure, and an outer peripheral surface is divided into two in the circumferential direction to be an N pole and an S pole. A magnet having a cylindrical rotor, a substantially U-shaped yoke having a magnetic pole portion disposed so as to face the outer peripheral surface of the rotor, and an excitation coil wound around the yoke. (For example, refer to Patent Document 1, Patent Document 2, Patent Document 3, and Patent Document 4).
In these electromagnetic actuators, the rotor is all formed in a cylindrical shape, and only the magnetized outer peripheral surface (radial magnetized portion) exerts a magnetic attractive force and a repulsive force on the yoke.

JP-A-9-152645 JP 2001-327143 A JP 2004-194403 A JP 2003-52162 A

  By the way, with the miniaturization of a digital camera or the like mounted on a mobile phone or the like, it is necessary to reduce the size of the mounted electromagnetic actuator. Therefore, if simply downsizing with the conventional configuration, the magnetized columnar rotor becomes smaller, the driving torque generated by the rotor when energized, and the magnetic attractive force when de-energized cannot be secured sufficiently, When used as a drive source for shutter blades or the like, it becomes difficult to stably drive the shutter blades and hold it at a predetermined position.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to ensure a desired driving torque, magnetic attractive force, etc. while reducing the size, and to provide shutter blades and apertures for cameras. Provided is an electromagnetic actuator capable of exhibiting stable driving force or holding force when applied as a driving source for driving blade members such as blades, ND filter blades, and other filter blades, and a camera blade drive using the same There is.

An electromagnetic actuator according to the present invention includes a rotor having a cylindrical outer peripheral surface centered on a predetermined axis and capable of rotating within a predetermined angular range, an excitation coil, and an arc surface facing the outer peripheral surface of the rotor. An electromagnetic actuator having a first magnetic pole portion and a yoke having a second magnetic pole portion that generate different magnetic poles when energized to the coil, wherein the rotor defines an outer peripheral surface and extends in the circumferential direction It is formed by magnetizing the same magnetic pole integrally with the radial magnetized portion so as to face the first magnetic pole portion and the second magnetic pole portion in the direction of the axis, and the radial magnetized portion magnetized with different magnetic poles. And a thrust magnetized portion.
According to this configuration, as the magnetized portion of the rotor, in addition to the radial magnetized portion defining the outer peripheral surface, the rotor is integrally formed with the radial magnetized portion and magnetized to the same magnetic pole as the radial magnetized portion. Since the thrust magnetized portion is provided, the thrust magnetized portion faces the first magnetic pole portion or the second magnetic pole portion of the yoke in the direction of the axis (rotation center line) of the rotor and exerts a magnetic action. Will increase.
As a result, when the coil is not energized, the thrust magnetized portion generates a strong magnetic attraction force between the first magnetic pole portion and the second magnetic pole portion to obtain a stable holding force, and when the coil is energized, An electromagnetic actuator in which the thrust magnetized portion generates a strong repulsive force due to electromagnetic force between the first magnetic pole portion and the second magnetic pole portion to obtain a stable driving torque and generate a desired holding force and driving torque. Can be obtained.

The said structure WHEREIN: The structure where the thrust magnetized part is integrally formed in the one end side of the radial magnetized part is employable.
According to this configuration, since the thrust magnetized portion is formed on one end side of the radial magnetized portion, the required drive is achieved while simplifying the structure and facilitating the assembly while facilitating the assembly. The torque and magnetic attractive force can be easily set.

In the above configuration, a configuration in which the thrust magnetized portion is integrally formed on both end sides of the radial magnetized portion can be employed.
According to this configuration, since the thrust magnetized portion is formed on both ends of the radial magnetized portion, a more powerful driving torque and magnetic attractive force can be easily set while simplifying the structure. be able to.

The said structure WHEREIN: The structure currently formed in the disk shape which makes a diameter larger than the diameter of a radial magnetized part is employable as a thrust magnetized part.
According to this configuration, since the thrust magnetized portion is formed in a disk shape over the entire circumference, the amount of rotation imbalance can be eliminated compared to the case where the thrust magnetized portion is provided locally, and stable and smooth. Rotational motion can be ensured.

A camera blade driving device according to the present invention includes a substrate having an opening for exposure, a blade member movably provided between a position facing the opening and a retreat position, and a drive source for driving the blade member The drive source is any one of the electromagnetic actuators described above.
According to this configuration, since the above-described electromagnetic actuator is employed as a drive source, a sufficient drive force is output from the rotor while the device is downsized, and the blade member is reliably stabilized at a desired timing. And is securely held at a predetermined position (for example, a position facing the opening or a position retracted from the opening).

According to the electromagnetic actuator having the above-described configuration, since the thrust magnetized portion is provided in addition to the radial magnetized portion as the rotor magnetized portion, the surface facing the yoke as a whole increases. Accordingly, it is possible to provide an electromagnetic actuator that generates a desired holding force and driving torque while achieving downsizing.
Further, according to the camera blade drive device having the above-described configuration, since the above-described electromagnetic actuator is employed as a drive source, a sufficient drive torque can be obtained by the rotor while reducing the size of the device. (For example, shutter blades, diaphragm blades, ND filter blades, other filter blades, etc.) can be driven stably and reliably at a desired timing, and a desired position (position facing the opening or opening) At a position retracted from the part).

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
1 to 5 show an embodiment in which an electromagnetic actuator according to the present invention is applied to a blade driving device for a camera. FIG. 1 is an exploded perspective view of the device, FIG. 2 is a sectional view of the device, and FIG. Fig. 4 is a perspective view and a sectional view of the electromagnetic actuator, and Figs. 4 and 5 are plan views showing a state in which the blade member is retracted from the opening and is in a position facing the opening.

  As shown in FIG. 1 to FIG. 3, this apparatus has a ground plate 10 and a back plate 20 as substrates having exposure openings 10a and 20a, and a position between the positions facing the openings 10a and 20a and the retracted position. A wing member 30 supported by the base plate 10 so as to be movable, and an electromagnetic actuator 40 as a drive source for driving the wing member 30 are provided.

The base plate 10 is formed of a resin material, and as shown in FIGS. 1 to 5, a circular exposure opening 10a, a support shaft 11 that rotatably supports a rotor 41, which will be described later, and a substantially fan-like shape. A through hole 10b, a positioning pin 12 for positioning a yoke 42 to be described later, a positioning protrusion 13, two support shafts 14 for rotatably supporting the blade member 30, two protrusions 15 for connecting the back plate 20, and a blade member The stopper 16 which stops 30 in an open position, the stopper 17 etc. which stop in a closed position are provided.
The back plate 20 is formed of a resin material or a thin metal plate. As shown in FIGS. 1 and 2, the back plate 20 includes a circular exposure opening 20a, a fan-shaped through hole 20b, and a support shaft 14. A circular hole 20c is formed, a circular hole 20d for fitting the stoppers 16 and 17 and a circular hole 20e for fitting the protrusion 15 are provided. The back plate 20 is connected to the back side of the base plate 10 at a predetermined interval, and defines a blade chamber W in which the blade member 30 is rotatably accommodated.

The blade member 30 is formed of a thin plate-like resin plate or the like, and includes two blades 31 and 32 as shown in FIGS. 1, 2, 4, and 5. Each of the blades 31 and 32 includes circular holes 31a and 32a into which the support shaft 14 is inserted, and long holes 31b and 32b into which drive pins 41c described later are inserted.
Then, as the drive pin 41c reciprocates, the blade member 30 is moved to the position retracted from the openings 10a and 20a (open position) as shown in FIG. 4 and the openings 10a and 20a as shown in FIG. It reciprocates between the facing position (closed position).
As the blade member 30, various blade members such as a shutter blade formed of a light-shielding plate, an ND filter blade that reduces the amount of light passing therethrough, or a filter blade that cuts infrared light are applied.

  As shown in FIGS. 1 to 5, the electromagnetic actuator 40 includes a rotor 41 that is rotatably supported within a predetermined angle range with respect to the base plate 10, and a yoke that is formed in a substantially U shape and is fixed to the base plate 10. 42, an exciting coil 43 wound around a bobbin 43a fitted to the yoke 42, a presser plate 44 fixed to the base plate 10, and the like.

As shown in FIGS. 1 to 3, the rotor 41 is formed in a stepped columnar shape, and includes a through hole 41 a ′ through which the support shaft 11 passes, an N pole outer peripheral surface 41 a ″, and an S pole outer peripheral surface 41 a ″. ′ Defining radial magnetized portion 41a, thrust magnetizing the N extreme surface 41b ″ and the S extreme surface 41b ″ formed integrally with the radial magnetized portion 41a and magnetized on the same magnetic pole The magnetic part 41b, the drive pin 41c etc. which were extended from the outer peripheral surface of the thrust magnetized part 41b in the radial direction and extended in the axis L direction are provided.
Here, in the rotor 41, as shown in FIG. 2, the radial magnetized portion 41a and the thrust magnetized portion 41b are formed of a magnetic material, and the drive pin 41c is formed of a resin material.

As shown in FIGS. 3A and 3B, the radial magnetized portion 41a is bisected in the circumferential direction so as to define a cylindrical outer peripheral surface, that is, by a surface passing through the axis L (rotation center line). The N pole outer peripheral surface 41 a ″ magnetized to the N pole and the S pole outer peripheral surface 41 a ″ ″ magnetized to the S pole are formed.
Further, the N pole outer peripheral surface 41a ″ and the S pole outer peripheral surface 41a ″ are opposed to an arc surface 42a ′ of a first magnetic pole portion 42a (to be described later) of the yoke 42 and an arc surface 42b ′ of the second magnetic pole portion 42b. It has become.

As shown in FIGS. 3 (a) and 3 (b), the thrust magnetic pole portion 41b is formed in a disc shape integrally with the radial magnetic pole portion 41a and having a diameter larger than the diameter of the radial magnetized portion 41a. The end face (upper surface) opposite to the side surface (lower surface) of the yoke 42 in the direction of the axis L is demarcated, that is, divided in the circumferential direction by the surface passing through the axis L (rotation center line), and is attached to the N pole. It is formed to have a magnetized N extreme surface 41b "and an S extreme surface 41b""magnetized in the S pole.
The N extreme surface 41 b ″ and the S extreme surface 41 b ″ are a side surface (lower surface) 42 a ″ of a first magnetic pole portion 42 a (to be described later) of the yoke 42 and a side surface (lower surface) 42 b ″ of the second magnetic pole portion 42 b. It comes to oppose.
Thus, since the thrust magnetized portion 41b is formed in a disk shape over the entire circumference, the amount of unbalance in rotation can be eliminated compared to the case where it is provided locally. Thereby, the rotor 41 can perform the stable smooth rotation operation.

  The drive pin 41c is formed integrally with the magnetized portions (radial magnetized portion 41a and thrust magnetized portion 41b) and transmits the rotational driving force of the rotor 41 to the outside, and is not magnetized by a resin material or the like. It is formed in magnetism.

As shown in FIGS. 1 and 3, the yoke 42 is formed to be bent in a substantially U shape. The first magnetic pole portion 42a is formed on one end side, the second magnetic pole portion 42b is formed on the other end side, and the ground plate is formed on the bent portion. Positioning holes 42c through which ten positioning pins 12 pass are provided.
The first magnetic pole part 42a has a circular arc surface 42a 'facing the radial magnetic pole part 41a (N-pole outer peripheral surface 41a''and S-pole outer peripheral surface 41a'') of the rotor 41, and the thrust magnetic pole part 41b (N extreme of the rotor 41). A side surface (lower surface) 42 a ″ that faces the surface 41 b ″ and the S extreme surface 41 b ″) is defined.
The second magnetic pole part 42b has a circular arc surface 42b 'facing the radial magnetic pole part 41a (N pole outer peripheral surface 41a''and S pole outer peripheral surface 41a'') of the rotor 41, and a thrust magnetic pole part 41b (N extreme It is formed so as to demarcate a side surface (lower surface) 42 b ″ facing the surface 41 b ″ and the S extreme surface 41 b ″).
The positioning hole 42c is formed so that the protrusion 12 of the main plate 10 is fitted.

As shown in FIG. 1, the coil 43 is wound around a bobbin 43 a, and the bobbin 43 a is fitted into the yoke 42 to be fixed to the yoke 42.
As shown in FIG. 1, the holding plate 44 is formed in a flat plate shape, and has a notch portion 44 a for receiving the bobbin portion 43 a, fitting holes 44 b and 44 c for passing the positioning pins 12 and the positioning protrusions 13 of the base plate 10, and the like. I have.

For assembly of the electromagnetic actuator 40 having the above-described configuration, first, the base plate 10, the rotor 41, the yoke 42, the coil 43 wound around the bobbin 43a, and the presser plate 44 are prepared.
Then, as shown in FIG. 1, the rotor 41 is rotatably fitted to the support shaft 11 of the base plate 10 so that the drive pin 41 c is passed through the through hole 10 b, and the bobbin 43 a is fitted to the yoke 42.
Subsequently, the positioning pin 12 is passed through the positioning hole 42 c and engaged with a positioning portion (not shown) of the base plate 10, and the yoke 42 to which the coil 43 is fixed is attached to the base plate 10.
Subsequently, the presser plate 44 is mounted from above the yoke 42 so that the positioning pin 12 and the positioning protrusion 13 are passed through the fitting holes 44b and 44c, and the tips of the positioning pin 12 and the positioning protrusion 13 are thermally crimped. The presser plate 44 is fixed to the main plate 10.
As a result, the rotor 41 is rotatably supported within a predetermined angle range with respect to the ground plane 10, and the yoke 42 and the coil 43 are firmly fixed to the ground plane 10.

As for the assembly of the camera blade drive device, as shown in FIGS. 1 and 2, the support shafts 14 and 14 are passed through the circular holes 31a and 32a with respect to the base plate 10 on which the assembly of the electromagnetic actuator 40 has been completed. And the blade member 30 (blade 31, 32) is attached to the main plate 10 so that the drive pin 41c is passed through the long holes 31b, 32b. Subsequently, the driving plate 41c is passed through the through hole 20b, the stoppers 16 and 17 are passed through the circular hole 20d, the back plate 20 is attached from the outside (back side) of the blade member 30, and the protrusions 15 and 15 are attached to the circular hole 20e. , 20e, and the front end is heat caulked to fix the back plate 20 to the main plate 10.
Thereby, the blade member 30 is supported in a swingable manner in the blade chamber W defined by the base plate 10 and the back plate 20 so as to open and close the openings 10a and 20a.

Next, the operation of the electromagnetic actuator 40 and the operation of the camera blade driving device will be described with reference to FIGS. In FIGS. 4 and 5, the presser plate 44 is removed, but the outer shape is represented by a two-dot chain line.
First, in a state where the coil 43 is not energized, as shown in FIG. 4, when the rotor 41 is positioned at the rotation end in the clockwise direction, the boundary line between the magnetic poles of the rotor 41 is the first magnetic pole portion 42a (arc surface 42a). ′, Side surface 42 a ″) and second magnetic pole part 42 b (arc surface 42 b ′, side surface 42 b ″) are stopped at positions deviated from the intermediate positions, so that N pole outer peripheral surface 41 a ″ and N extreme Between the surface 41 b ″ and the second magnetic pole part 42 b (arc surface 42 b ′, side surface 42 b ″), the S pole outer peripheral surface 41 a ″ and the S extreme surface 41 b ″ and the first magnetic pole part 42 a (arc surface) 42 a ′ and side surfaces 42 a ″), magnetic attraction forces are generated respectively, and the rotor 41 is stopped and held securely at the clockwise rotation end.
This state corresponds to a state in which the blade member 30 of the camera blade drive device is positioned at a position (open position) that is in contact with the stopper 16 and retracted from the openings 10a and 20a, as shown in FIG.

In this state, when the coil 43 is energized in a predetermined direction, an S pole is generated in the first magnetic pole portion 42a and an N pole is generated in the second magnetic pole portion 42b.
Thereby, between the N pole outer peripheral surface 41a ″ and the N extreme surface 41b ″ and the second magnetic pole part 42b (the arc surface 42b ′, the side surface 42b ″), the S pole outer peripheral surface 41a ″ and the S extreme surface. 41b ″ and the first magnetic pole portion 42a (arc surface 42a ′, side surface 42a ″), a repulsive force is generated by an electromagnetic force, and a strong rotational torque is generated. The rotor 41 is counterclockwise. Begin to rotate around.

As shown in FIG. 5, when the rotor 41 reaches the counterclockwise rotation end, the N pole outer peripheral surface 41a '' and the N extreme surface 41b '' and the first magnetic pole portion 42a (the arc surface 42a ', the side surface 42a). ″), And between the S pole outer peripheral surface 41 a ″ and the S extreme surface 41 b ″ and the second magnetic pole part 42 b (arc surface 42 b ′, side surface 42 b ″) due to electromagnetic force, respectively. A suction force is generated, and a rotational biasing force that further rotates the rotor 41 counterclockwise is generated.
In this state, when the power supply to the coil 43 is cut off, the attraction force due to the electromagnetic force changes to the magnetic attraction force, and the rotor 41 stops at the counterclockwise rotation end and is securely held. It will be.
This state corresponds to a state in which the blade member 30 of the camera blade drive device is positioned at a position (closed position) that contacts the stopper 17 and faces the openings 10a and 20a as shown in FIG.

On the other hand, when the coil 43 is energized in the reverse direction, opposite magnetic poles are generated in the first magnetic pole part 42a and the second magnetic pole part 42b, respectively, and the rotor 41 rotates clockwise, and the clockwise rotation shown in FIG. It is positioned and held at the rotation end of.
At this time, in the blade drive device for a camera, the blade member 30 is moved from the position (closed position) that contacts the stopper 17 and faces the openings 10a and 20a as shown in FIG. 5 to the stopper 16 as shown in FIG. It moves and positions to the position (open position) which contact | abutted and retracted from opening part 10a, 20a.

  Thus, with respect to the rotor 41, in addition to the radial magnetic pole portion 41a (N pole outer peripheral surface 41a ″ and S pole outer peripheral surface 41a ″), the thrust magnetic pole portion 41b (N extreme surface 41b ″ and S extreme outer surface 41a ″). By providing the surface 41b ″ ′), the rotor 41 can obtain a stable rotational force. Therefore, a stable driving torque can be obtained by the driving pin 41c, and the rotor 41 can generate a desired holding force (magnetic attraction force) at the rotating ends on both sides. When used as a drive source of the drive device, the blade member 30 can be driven smoothly and stably.

FIG. 6 shows a state in which the camera blade driving device M using the electromagnetic actuator 40 as a driving source is mounted on the mobile phone 50.
The mobile phone 50 includes a main body 51 provided with various operation buttons 51a, a cover 52 provided with a monitor 52a that is rotatably connected to the main body 51 and displays various information, and an outer surface of the cover 52. A camera blade driving device M and the like housed so as to have a photographing window 52b are provided.
As described above, the camera blade driving device M using the electromagnetic actuator 40 as a driving source can obtain a sufficient driving torque by the rotor 41 while reducing the size of the device, and thus the blade member 30 (for example, the shutter blade). , Diaphragm blades, ND filter blades, other filter blades, etc.) can be reliably driven at a desired timing, and can be driven at desired positions (positions facing the openings 10a and 20a, or the openings 10a). , 20a, the position retracted from 20a).

FIGS. 7 to 11 show a camera blade drive device using an electromagnetic actuator 140 according to another embodiment of the present invention as a drive source, and the embodiment described above except that the rotor 141 and the holding plate 144 are changed. Therefore, the same components are denoted by the same reference numerals and description thereof is omitted.
In this electromagnetic actuator 140, as shown in FIGS. 7 to 9, the rotor 141 is formed in a stepped cylindrical shape having two discs on both ends, and through-holes 141a ′, through which the support shaft 11 is passed. A radial magnetized portion 141a that defines an N-pole outer peripheral surface 141a '' and an S-pole outer peripheral surface 141a '', and an N extreme surface 141b that is formed integrally with the radial magnetized portion 141a and magnetized to the same magnetic pole ″, 141d ″ and S extreme surfaces 141b ″ ″, 141d ″ ″ projecting from the outer peripheral surfaces of the two thrust magnetized portions 141b, 141d and the thrust magnetized portion 141b in the radial direction and in the axis L direction And a drive pin 141c and the like formed to extend. Here, in the rotor 141, as shown in FIG. 8, the radial magnetized portion 141a and the thrust magnetized portions 141b and 141d are formed of a magnetic material, and the drive pin 141c is formed of a resin material.

As shown in FIGS. 9A and 9B, the radial magnetized portion 141a is divided in the circumferential direction so as to define a cylindrical outer peripheral surface, that is, by a surface passing through the axis L (rotation center line). The N pole outer peripheral surface 141a ″ magnetized to the N pole and the S pole outer peripheral surface 141a ″ ″ magnetized to the S pole are formed.
The N pole outer peripheral surface 141 a ″ and the S pole outer peripheral surface 141 a ″ are opposed to the arc surface 42 a ′ of the first magnetic pole portion 42 a of the yoke 42 and the arc surface 42 b ′ of the second magnetic pole portion 42 b. Yes.

As shown in FIGS. 9A and 9B, the thrust magnetic pole portion 141b is formed in a disc shape integrally with one end side of the radial magnetic pole portion 141a and having a diameter larger than the diameter of the radial magnetized portion 141a. At the same time, the end face opposite to the side surface of the yoke 42 in the direction of the axis L is demarcated, that is, divided in the circumferential direction by a plane passing through the axis L (rotation center line) and magnetized to the N pole. The N extreme surface 141b ″ and the S extreme surface 141b ″ ″ magnetized on the S pole are formed.
The N extreme surface 141b ″ and the S extreme surface 141b ″ are opposed to the side surface (lower surface) 42a ″ of the first magnetic pole portion 42a and the side surface (lower surface) 42b ″ of the second magnetic pole portion 42b. It is like that.

As shown in FIGS. 9 (a) and 9 (b), the thrust magnetic pole portion 141d is formed in a disc shape integrally with the other end side of the radial magnetic pole portion 141a and having a diameter larger than the diameter of the radial magnetized portion 141a. In addition to being formed, an end face facing the side surface of the yoke 42 in the direction of the axis L is demarcated, that is, divided in the circumferential direction by a plane passing through the axis L (rotation center line) and magnetized to the N pole. In addition, the N extreme surface 141d "and the S extreme surface 141d""magnetized in the S pole are formed.
Further, the N extreme surface 141d ″ and the S extreme surface 141d ″ are the side surface (upper surface) 42a ″ of the first magnetic pole portion 42a of the yoke 42 and the side surface (upper surface) 42b ″ of the second magnetic pole portion 42b. It comes to oppose.
Thus, since the thrust magnetized portions 141b and 141d are formed in a disk shape over the entire circumference, the amount of rotational imbalance can be eliminated as compared with the case where they are provided locally. Thereby, the rotor 141 can perform a stable and smooth rotational operation.

  The drive pin 141c is formed integrally with the magnetized portion (radial magnetized portion 141a and thrust magnetized portion 141b, 141d), and transmits the rotational driving force of the rotor 141 to the outside. It is formed non-magnetized.

  7 and 8, the presser plate 144 is formed in a flat plate shape, and includes a bobbin portion 144a around which the coil 43 is wound, a fitting hole 144b through which the positioning pin 12 and the positioning projection 13 of the base plate 10 pass. 144c, a support shaft 144d that rotatably supports the rotor 141, and the like.

Regarding the assembly of the electromagnetic actuator 140 having the above-described configuration, first, the presser plate 144 in which the coil 43 is wound around the base plate 10, the rotor 141, the yoke 42, and the bobbin 144a is prepared. Then, as shown in FIG. 7, after the rotor 141 is rotatably fitted to the support shaft 144d of the presser plate 144, the rotor 141 is pressed by a fingertip or the like so as not to fall off from the support shaft 144d.
Subsequently, the yoke 42 is fitted into the fitting hole formed in the bobbin portion 144 a of the pressing plate 144 while being opposed to the radial magnetized portion 141 a of the rotor 141, and the yoke 42 is fixed to the pressing plate 144.
In this state, the rotor 141 does not fall off from the support shaft 144d. Subsequently, the positioning pin 12 and the positioning projection 13 are fitted to the positioning hole 42c and the fitting hole 144b so that the drive pin 141c is passed through the through hole 10b. The presser plate 144 is attached through the hole 144c, and the tips of the positioning pin 12 and the positioning projection 13 are caulked to fix the presser plate 144 to the base plate 10.
As a result, the rotor 141 is rotatably supported within a predetermined angle range with respect to the ground plane 10, and the yoke 42 and the coil 43 are firmly fixed to the ground plane 10.
The assembly of the camera blade driving device is performed in the same manner as described above with respect to the base plate 10 on which the assembly of the electromagnetic actuator 140 has been completed.

Next, the operation of the electromagnetic actuator 140 and the operation of the camera blade driving device will be described with reference to FIGS.
First, in a state where the coil 43 is not energized, as shown in FIG. 10, when the rotor 141 is positioned at the rotation end in the clockwise direction, the boundary line of the magnetic poles of the rotor 141 is the first magnetic pole portion 42a (arc surface 42a). ′, Side surfaces 42 a ″, 42 a ″ ″) and the second magnetic pole part 42 b (circular surface 42 b ′, side surfaces 42 b ″, 42 b ″) are stopped at positions shifted from the respective intermediate positions. Between the N pole outer peripheral surface 141a ″ and the N extreme surfaces 141b ″, 141d ″ and the second magnetic pole part 42b (the arc surface 42b ′, the side surfaces 42b ″, 42b ″), the S pole outer peripheral surface 141a ′. ″ And S extreme surfaces 141 b ″, 141 d ″ ″ and the first magnetic pole part 42 a (arc surface 42 a ′, side surfaces 42 a ″, 42 a ″ ″), magnetic attraction force is generated respectively. Thus, the rotor 141 stops at the clockwise rotation end and is securely held.
This state corresponds to a state in which the blade member 30 of the camera blade drive device is positioned at a position (open position) that is in contact with the stopper 16 and retracted from the openings 10a and 20a, as shown in FIG.

In this state, when the coil 43 is energized in a predetermined direction, an S pole is generated in the first magnetic pole portion 42a and an N pole is generated in the second magnetic pole portion 42b.
Thereby, between the N pole outer peripheral surface 141a ″ and the N extreme surfaces 141b ″, 141d ″ and the second magnetic pole portion 42b (the arc surface 42b ′, the side surfaces 42b ″, 42b ″), the S pole outer periphery. Between the surface 141 a ″ and the S extreme surfaces 141 b ″, 141 d ″ and the first magnetic pole part 42 a (the arc surface 42 a ′, the side surfaces 42 a ″, 42 a ″), due to electromagnetic force, respectively. A repulsive force is generated to generate a strong rotational torque, and the rotor 141 starts to rotate counterclockwise.

Then, as shown in FIG. 11, when the rotor 141 reaches the counterclockwise rotation end, the N pole outer peripheral surface 141a ″ and the N extreme surfaces 141b ″ and 141d ″ and the first magnetic pole portion 42a (the arc surface 42a). ', Side surfaces 42a'',42a''), S pole outer peripheral surface 141a''''and S extreme surfaces 141b'''',141d''''and second magnetic pole part 42b (arc surface 42b'', side surface). 42b ″, 42b ″ ′), a suction force is generated by an electromagnetic force, and a rotational biasing force that further rotates the rotor 141 counterclockwise is generated.
In this state, when the coil 43 is de-energized, the attraction force by the electromagnetic force is changed to the magnetic attraction force, and the rotor 141 is stopped and held securely at the counterclockwise rotation end. It will be.
This state corresponds to a state in which the blade member 30 of the camera blade driving device is positioned at a position (closed position) that contacts the stopper 17 and faces the openings 10a and 20a as shown in FIG.

On the other hand, when the coil 43 is energized in the reverse direction, opposite magnetic poles are generated in the first magnetic pole part 42a and the second magnetic pole part 42b, respectively, and the rotor 141 rotates clockwise, and the clockwise rotation shown in FIG. It is positioned and held at the rotation end of.
At this time, the blade member 30 of the camera blade driving device contacts the stopper 16 as shown in FIG. 10 from the position (closed position) that contacts the stopper 17 and faces the openings 10a and 20a as shown in FIG. Then, the position is moved to the position (open position) retracted from the openings 10a and 20a.

  Thus, in addition to the radial magnetic pole portion 141a (N pole outer peripheral surface 141a ″ and S pole outer peripheral surface 141a ″), the rotor 141 has two thrust magnetic pole portions 141b and 141d (N extreme surface 141b ′). ′, 141d ″ and S extreme surface 141b ″ ″, 141d ″ ″), the rotor 141 can obtain more stable rotational force. Accordingly, a more stable and powerful driving torque can be obtained by the driving pin 141c, and the rotor 141 can generate a desired holding force (magnetic attraction force) at the rotating ends on both sides. Is used as a drive source of the camera blade drive device, the blade member 30 can be driven smoothly and stably.

In the above embodiment, the blade driving device for a camera employing the electromagnetic actuators 40 and 140 according to the present invention as a driving source for driving the blade member 30 including the two blades 31 and 32 is shown. The electromagnetic actuator according to the present invention may be employed as a drive source for driving a blade member composed of one blade or three or more blades.
In the above embodiment, the case where the drive pins 41c and 141c are formed of a member different from the magnetized portion is shown, but the present invention is not limited to this, and the drive pins 41c and 141c may be integrally formed with the same material as the magnetized portion. Good.

  As described above, since the electromagnetic actuator of the present invention can generate a desired holding force and driving torque while achieving a reduction in size, it can be applied as a driving source of a camera blade driving device. In addition, it is useful as a drive source for other optical devices or electronic devices that require the driven member to reciprocate.

It is a disassembled perspective view which shows the blade drive device for cameras carrying the electromagnetic actuator which concerns on this invention. FIG. 2 is a developed cross-sectional view of the camera blade driving device shown in FIG. 1. FIG. 2 shows a part of the electromagnetic actuator mounted on the apparatus shown in FIG. 1, (a) is a perspective view thereof, and (b) is a sectional view taken along line E1-E1 in (a). FIG. 5 is a plan view for explaining the operation of the camera blade driving device shown in FIG. 1 and showing a state where the blade member is in a position retracted from the opening. FIG. 2 is a plan view for explaining the operation of the camera blade driving device shown in FIG. 1 and showing a state in which a blade member is in a position facing an opening. It is a perspective view which shows the mobile phone carrying the camera blade | wing drive device which concerns on this invention. It is a disassembled perspective view which shows the blade drive device for cameras carrying the electromagnetic actuator which concerns on other embodiment of this invention. FIG. 8 is a developed cross-sectional view of the camera blade driving device shown in FIG. 7. FIG. 8 shows a part of the electromagnetic actuator mounted on the apparatus shown in FIG. 7, (a) is a perspective view thereof, and (b) is a sectional view taken along line E2-E2 in (a). FIG. 8 is a plan view for explaining the operation of the camera blade driving device shown in FIG. 7 and showing a state in which the blade member is in a position retracted from the opening. FIG. 9 is a plan view for explaining the operation of the camera blade driving device shown in FIG. 7 and showing a state where the blade member is in a position facing the opening.

Explanation of symbols

10 Ground plane (substrate)
20 Back plate (substrate)
10a, 20a Exposure openings 11, 14 Support shaft 30 Blade member 31, 32 Blade 40, 140 Electromagnetic actuator (drive source)
41, 141 Rotor 41a, 141a Radial magnetized part 41a ', 141a' Through hole 41a ", 141a" N pole outer peripheral surface 41a "", 141a "" S pole outer peripheral surface 41b ", 141b", 141d ″ N extreme surface 41b ″ ″, 141b ″ ″, 141d ″ ″ S extreme surface 41c, 141c Drive pin 42 Yoke 42a First magnetic pole portion 42a ′ Arc surface 42a ″, 42a ″ ″ Side surface 42b First 2 magnetic pole part 42b 'Arc surface 42b ", 42b" side surface 43 Excitation coil 44, 144 Presser plate 144d Support shaft

Claims (5)

A rotor having a cylindrical outer peripheral surface centered on a predetermined axis and capable of rotating within a predetermined angular range; an excitation coil; and an arc surface opposed to the outer peripheral surface of the rotor; An electromagnetic actuator comprising a yoke having a first magnetic pole part and a second magnetic pole part that generate different magnetic poles by energization of
The rotor defines a radial magnetized portion that defines the outer peripheral surface and is magnetized with different magnetic poles in the circumferential direction, and the radial magnetized so as to face the first magnetic pole portion and the second magnetic pole portion in the axial direction. A thrust magnetized portion formed integrally with the magnetic portion and magnetized on the same magnetic pole,
An electromagnetic actuator characterized by that. The thrust magnetized portion is integrally formed on one end side of the radial magnetized portion,
The electromagnetic actuator according to claim 1. The thrust magnetized portion is integrally formed on both end sides of the radial magnetized portion,
The electromagnetic actuator according to claim 1. The thrust magnetized portion is formed in a disk shape having a diameter larger than the diameter of the radial magnetized portion.
The electromagnetic actuator according to any one of claims 1 to 3, wherein A substrate having an opening for exposure, a blade member provided movably between a position facing the opening and a position retracted, and a drive source for driving the blade member,
The drive source is an electromagnetic actuator according to any one of claims 1 to 4.
A blade drive device for a camera.

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