JP2007295771A - Electromagnetic actuator and blade drive unit for camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To raise rotational driving force and coercive force of an electromagnetic actuator. <P>SOLUTION: The electromagnetic actuator comprises a rotor 410 which includes a cylindrical magnetizing part 412 for defining magnetized outer peripheral surfaces 412a and 412b to rotate within specified angles, a coil 430 for excitation, and yoke 420 comprising a first magnetic pole part 421 and second magnetic pole part 422 which define first arc surfaces 421a and 421a' and second arc surfaces 422a and 422a', facing the outer peripheral surface of the rotor with a specified space, for generating magnetic poles different from each other, by energizing the coil. The first magnetic pole part 421 and the second magnetic pole part 422 comprise a first counter surface 421b and second counter surface 422b which are continuously formed to the first arc surface and the second arc surface and so formed as to continuously change the distance from the counter outer peripheral surface of the rotor. Thus, only by changing shape of a yoke, structure is simplified and size is reduced, assuring a desired driving torque and coercive force. <P>COPYRIGHT: (C)2008,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 magnetized columnar rotor, a substantially U-shaped yoke having a magnetic pole portion defining an arc surface disposed so as to face the outer peripheral surface of the rotor, an exciting coil wound around the yoke, etc. (For example, refer to Patent Document 1, Patent Document 2, Patent Document 3, Patent Document 4, and Patent Document 5).

In these electromagnetic actuators, the rotor is formed in a cylindrical shape so as to define an outer peripheral surface magnetized in the N-pole and the S-pole in the circumferential direction, and the magnetic pole portion of the yoke is formed in a radial direction with respect to the outer peripheral surface of the rotor. To define a plurality of arcuate surfaces that are concavity and convexity in the radial direction so as to face each other at a predetermined angle with a continuous arc surface facing each other at a predetermined interval. Is formed.
The outer peripheral surface of the magnetized rotor exerts a magnetic attraction force and a repulsive force on a continuous arc surface (magnetic pole portion) of the yoke or a discontinuous arc surface (magnetic pole portion) having irregularities in the radial direction. It has become. Therefore, in order to increase the driving force or increase the operating speed when the outer peripheral surface of the rotor faces a continuous circular arc surface having a constant interval, it is necessary to increase the operating voltage. Further, when the outer peripheral surface of the rotor faces discontinuous circular arc surfaces with different intervals, the magnetic attractive force and the repulsive force acting on the rotor change rapidly, and it is difficult to obtain smooth rotation. .

JP 2001-327143 A JP 2003-274629 A JP 2003-189575 A JP 2004-095703 A JP 2004-032873 A

By the way, along with the downsizing of digital cameras and the like mounted on mobile phones, etc., it is necessary to reduce the size and power consumption of the mounted electromagnetic actuators, and the rotor operates freely due to external impacts, etc. Therefore, it is necessary to increase the holding force for holding the rotor at a predetermined stop position.
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 its object is to achieve desired driving torque, magnetic attraction force (holding force), etc. while achieving downsizing, low power consumption, and the like. And an electromagnetic actuator capable of exhibiting a stable driving force or holding force when applied as a driving source for driving a blade member such as a shutter blade, diaphragm blade, ND filter blade, or other filter blade of a camera. It is in providing the blade drive for cameras which used.

The electromagnetic actuator according to the present invention includes a cylindrical magnetized portion that defines an outer circumferential surface magnetized in the circumferential direction, a rotor that can rotate within a predetermined angular range, an excitation coil, and an outer circumferential surface of the rotor at a predetermined interval. An electromagnetic actuator comprising a yoke having a first magnetic pole part and a second magnetic pole part that define a first arc face and a second arc face that face each other and generate different magnetic poles by energizing the coil, The first magnetic pole part and the second magnetic pole part are formed so as to be continuously formed on the first arc surface and the second arc surface, respectively, and to continuously change the interval facing the outer peripheral surface of the rotor. It has 1 opposing surface and 2nd opposing surface, It is characterized by the above-mentioned.
According to this configuration, since the first magnetic pole part and the second magnetic pole part have the first opposed surface and the second opposed surface that continuously change the distance from the outer peripheral surface of the rotor, the N pole or S pole of the rotor As the magnetized outer peripheral surface approaches the first opposing surface or the second opposing surface, the magnetic attractive force or repulsive force gradually increases, and the outer periphery magnetized on the north or south pole of the rotor As the surface moves away from the first facing surface or the second facing surface, the magnetic attractive force or repulsive force gradually decreases.
Therefore, the rotor can rotate smoothly and quickly to generate a large rotational driving force (driving torque), and at both end positions (stopped positions) of the operating range, the rotor can be driven by a large magnetic holding force. It can be held at that stop position. In addition, if the conventional rotational driving force (driving torque) is acceptable, the driving voltage can be reduced and the power consumption can be reduced.
In this way, since the shape of the yoke is merely changed without providing any special parts, the desired driving torque, magnetic attraction force ( Holding force) and the like.

In the configuration described above, a configuration in which the first facing surface and the second facing surface are formed point-symmetrically with respect to the rotation axis of the rotor can be employed.
According to this configuration, it is possible to perform a point-symmetric rotating operation with respect to the rotor by switching the energization direction to the coil.

In the configuration described above, a configuration in which the first facing surface and the second facing surface are formed as flat surfaces that are flat in a direction perpendicular to the center line of the operating range of the magnetic pole boundary surface of the rotor can be employed. .
According to this configuration, the shape of the yoke can be simplified and the manufacture is facilitated. Further, the same operating characteristics with no directivity (rotational driving force, magnetic holding force) in the forward and backward movement of the rotor. And can be easily applied as a reciprocating drive source for various devices.

In the above configuration, the rotor is formed to protrude in the radial direction from the outer peripheral surface so as to face the first magnetic pole part and the second magnetic pole part in the direction of the rotation axis, and is attached to the same magnetic pole as the cylindrical magnetized part. A configuration including a thrust magnetized portion formed by magnetism can be employed.
According to this configuration, the magnetized portion of the rotor is formed integrally with the cylindrical magnetized portion and magnetized to the same magnetic pole as the cylindrical magnetized portion, in addition to the cylindrical magnetized portion defining the outer peripheral surface. By providing the thrust magnetized portion, the thrust magnetized portion faces the first magnetic pole portion or the second magnetic pole portion of the yoke in the direction of the rotation axis of the rotor, and the number of surfaces that exert a magnetic action increases.
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, The thrust magnetized portion generates a strong repulsive force and attractive force due to electromagnetic force between the first magnetic pole portion and the end surface in the rotation axis direction of the second magnetic pole portion, and a desired rotational driving force (driving torque) and holding An electromagnetic actuator that generates force can be obtained.

In the above configuration, a configuration in which the thrust magnetized portion is integrally formed on one end side of the cylindrical magnetized portion can be adopted.
According to this configuration, since the thrust magnetized portion is formed on one end side of the cylindrical magnetized portion, the required driving torque, magnetic attraction force and repulsion can be achieved while simplifying the structure and reducing the thickness. The power can be set easily.

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

The said structure WHEREIN: The structure currently formed in the disk shape which makes a diameter larger than the diameter of a cylindrical 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 electromagnetic actuator described above is employed as the drive source, the rotor generates sufficient electromagnetic drive force and magnetic holding force while the apparatus is downsized, and the blade member has the desired timing. Thus, it is reliably and quickly driven, and is reliably 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 configuration, the electromagnetic driving force is continuously changed by providing the first opposing surface and the second opposing surface that continuously change the distance between the yoke and the outer peripheral surface of the rotor. (Change in strength) can be provided, quick starting characteristics, large rotational driving force, large magnetic holding force at the time of stopping can be obtained, and thrust in addition to cylindrical magnetized part as rotor magnetized part By providing the magnetized portion, the entire surface of the rotor that faces the yoke is increased, and an electromagnetic actuator that generates a desired holding force and driving torque can be provided 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 6 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 a front view of the device, FIG. 2 is a sectional view of the device, and FIG. FIG. 4 is a partially enlarged view for explaining the electromagnetic actuator, and FIGS. 5 and 6 are plan views showing a state in which the blade member is retracted from the opening and at a position facing the opening. is there.

  As shown in FIGS. 1 to 3, the apparatus includes a base plate 10 having an exposure opening 10a, a back plate 20 having an opening 20a, a position facing the openings 10a and 20a, and a retracted position. The blade member 30 is supported by the base plate 10 so as to be freely movable between them, and an electromagnetic actuator 400 as a drive source for driving the blade member 30 is provided.

The base plate 10 is formed of a resin material, and as shown in FIGS. 1, 2, 5, and 6, a circular exposure opening 10a and a support for rotatably supporting a rotor 410, which will be described later, are supported. The shaft 11, the substantially fan-shaped through hole 12, the positioning projection 13 for positioning and fixing the later-described yoke 420 and the pressing plate 440, the positioning projection 14 for positioning and fixing the pressing plate 440 described later, and the blade member 30 are rotatable. Are provided with a supporting shaft 15, two projections 16 for coupling the back plate 20, a stopper 17 for stopping the blade member 30 in the open position, a stopper 18 for stopping the blade member 30 in the closed position, and the like.
The back plate 20 is formed of a resin material or a thin metal plate or the like, and as shown in FIG. 2, a circular opening 20a, a fan-shaped through hole 21, a circular hole 22 through which the support shaft 15 passes, and a protrusion 16 is provided with a circular hole 23 into which 16 is fitted, a fitting hole (not shown) into which stoppers 17 and 18 are fitted. Then, the back plate 20 is connected to the back side of the base plate 10 at a predetermined interval by crushing (thermally caulking) the tip of the protrusion 16 to accommodate the blade member 30 in a rotatable manner. Is defined.

The blade member 30 is formed of a thin plate-like resin plate or the like. As shown in FIGS. 1, 2, 5, and 6, a circular hole 31 into which the support shaft 15 is inserted and a drive pin 413 to be described later are provided. A long hole 32 to be inserted is provided.
Then, as the drive pin 413 reciprocates, the blade member 30 is moved to the position retracted from the openings 10a and 20a (open position) as shown in FIG. 5 and the openings 10a and 20a as shown in FIG. It reciprocates between the facing position (closed position).
The blade member 30 may be a shutter blade formed of a light-shielding plate, a diaphragm blade having an opening smaller in diameter than the opening for exposure, an ND filter blade that reduces the amount of light passing through, or a red blade. Various blade members such as filter blades for cutting outside light are applied.

  As shown in FIGS. 1 to 6, the electromagnetic actuator 400 has a rotor 410 that is rotatably supported within a predetermined angle range (operating angle θ) with respect to the base plate 10. Yoke 420 fixed to the coil, coil 430 for excitation, and bobbin 441 that integrally defines a fitting hole 441a for fitting the coil 420, and a presser plate 440 that is fixed to the base plate 10 integrally. Etc. are formed.

As shown in FIGS. 2 to 6, the rotor 410 is formed in a cylindrical shape, and has a through hole 411 through which the support shaft 11 passes, an N pole outer peripheral surface 412 a and an S pole divided in the circumferential direction by a magnetic pole boundary surface BS. A cylindrical magnetized portion 412 that defines the outer peripheral surface 412b, a drive pin 413 that protrudes in the radial direction from the outer peripheral surface of the cylindrical magnetized portion 412 and that extends in the direction of the rotation axis L are provided.
Here, as shown in FIG. 2, the rotor 410 has a cylindrical magnetized portion 412 formed of a magnetic material and a drive pin 413 formed of a resin material.

As shown in FIGS. 3A and 4 to 6, the cylindrical magnetized portion 412 is bisected in the circumferential direction so as to define a cylindrical outer peripheral surface, that is, by a magnetic pole boundary surface BS passing through the rotation axis L. Thus, an N pole outer peripheral surface 412a magnetized at the N pole and an S pole outer peripheral surface 412b magnetized at the S pole are formed.
Further, the N pole outer peripheral surface 412a and the S pole outer peripheral surface 412b are a first magnetic pole portion 421 (first arc surfaces 421a and 421a ′ and a first opposing surface 421b thereof) and a second magnetic pole portion 422 (to be described later) of the yoke 420. The second arcuate surfaces 422a and 422a ′ and the second facing surface 422b) are opposed to each other.
The drive pin 413 is integrally formed with the cylindrical magnetized portion 412 and transmits the rotational driving force of the rotor 410 to the outside, and is formed non-magnetized with a resin material or the like.

As shown in FIGS. 1 to 6, the yoke 420 is formed to be bent in a substantially U shape, and has a first magnetic pole portion 421 at one end, a second magnetic pole portion 422 at the other end, and a ground plane at the bent portion. Positioning holes 423 for passing ten positioning pins 13 are provided.
As shown in FIGS. 3A and 4, the first magnetic pole portion 421 is spaced apart from the cylindrical magnetic pole portion 412 (N-pole outer peripheral surface 412 a and S-pole outer peripheral surface 412 b) of the rotor 410. The opposing first arcuate surfaces 421a and 421a ′ are formed so as to demarcate the opposing first opposing surfaces 421b so as to continuously change the interval. The first facing surface 412b is formed continuously with the first arcuate surfaces 421a and 421a ′ located on both sides.
As shown in FIG. 4, the second magnetic pole portion 422 is a second arcuate surface facing the cylindrical magnetic pole portion 412 (N-pole outer peripheral surface 412 a and S-pole outer peripheral surface 412 b) of the rotor 410 at a predetermined interval. 422a and 422a ′ are formed so as to delimit a second opposing surface 422b facing each other so as to continuously change the interval. The second opposing surface 422b is formed continuously with the second arcuate surfaces 422a and 422a 'located on both sides.

As described above, the first opposing surface 421b and the second opposing surface 422b that continuously change the distance from the outer peripheral surfaces 412a and 412b of the rotor 410 are provided for the first magnetic pole portion 421 and the second magnetic pole portion 422. As a result, the magnetic attractive force or repulsive force gradually increases as the outer peripheral surfaces 412a and 412b magnetized to the N-pole or S-pole of the rotor 410 approach the first opposing surface 421b or the second opposing surface 422b. In addition, as the outer peripheral surfaces 412a and 412b magnetized to the N-pole or S-pole of the rotor 410 move away from the first opposing surface 421b or the second opposing surface 422b, the magnetic attractive force or repulsive force gradually decreases. .
Therefore, the rotor 410 can rotate smoothly and quickly to generate a large rotational driving force (driving torque), and the rotor 410 can be moved by a large magnetic holding force at both end positions (stop positions) of the operating range. It can be held at that stop position.
Further, if the conventional rotational driving force (driving torque) is sufficient, the driving voltage can be reduced to reduce the power consumption.
That is, by simply changing the shape of the yoke 420 without providing any special parts, the structure can be simplified, reduced in size, reduced in power consumption, etc., and desired driving torque, magnetic attraction force (holding force) can be achieved. ) Etc. can be secured.

Here, as shown in FIG. 4, the first facing surface 421 b and the second facing surface 422 b are formed point-symmetrically with respect to the rotation axis L of the rotor 410, and the operating range of the magnetic pole boundary surface BS of the rotor 410. (Working angle) It is formed as a flat surface that is flat in a direction perpendicular to the center line C of θ.
According to this, by switching the energization direction to the coil 430, it is possible to perform a point-symmetric rotational operation with respect to the rotor 410, simplify the shape of the yoke 430 and at the same time facilitate manufacture. Furthermore, the same operating characteristics (rotational driving force, magnetic holding force) having no directionality can be obtained by the forward and backward movements of the rotor 410, and it is easy as a driving source for reciprocating various devices. Can be applied to.

  As shown in FIGS. 1 and 2, the coil 430 is wound around a bobbin 441 of a presser plate 440 described later, and the second magnetic pole portion 422 of the yoke 420 is fitted into the fitting hole 441a of the bobbin 441. The coil 430 is wound around the yoke 420.

  As shown in FIGS. 1 and 2, the holding plate 440 is formed in a flat plate shape using a resin material or the like, and includes a bobbin 441 that defines a fitting hole 441 a into which the yoke 420 is fitted, and a positioning projection of the base plate 10. 13 and 14 are provided with fitting holes 442, 443 and the like.

For assembly of the electromagnetic actuator 400 having the above-described configuration, first, the base plate 10, the rotor 410, the yoke 420, the coil 430, and the presser plate 440 are prepared.
Then, as shown in FIG. 1, the rotor 410 is rotatably fitted to the support shaft 11 of the base plate 10 so that the drive pin 413 is passed through the through hole 12, and the fitting hole 441 a of the bobbin 441 around which the coil 430 is wound. The yoke 420 is fitted into the arm.
Subsequently, the positioning hole 423 and the fitting hole 442 are externally fitted to the positioning protrusion 13, and the fitting hole 443 is externally fitted to the positioning protrusion 14 so that the tips of the positioning protrusions 13 and 14 are respectively fitted. The yoke 420 and the presser plate 440 are mounted on the main plate 10 by crushing (thermally crimping).
As a result, the rotor 410 is rotatably supported within a predetermined angle range with respect to the ground plane 10, and the yoke 420 and the coil 430 are firmly fixed to the ground plane 10.

As for the assembly of the camera blade driving device, as shown in FIGS. 1 and 2, the support shaft 15 is passed through the circular hole 31 and the long hole 32 is attached to the base plate 10 on which the assembly of the electromagnetic actuator 400 has been completed. The blade member 30 is attached to the main plate 10 so that the driving pin 413 is passed through the base plate 10. Subsequently, the back plate 20 is attached from the outside (back side) of the blade member 30, and the two protrusions 16 are passed through the circular holes 23, and then the tips thereof are crushed (heat caulked), and the back plate 20 is attached to the base plate 10. Fix it.
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 400 and the operation of the camera blade driving device will be described with reference to FIGS. 5 and 6, the presser plate 440 is omitted.
First, when the rotor 410 is positioned at the clockwise rotation end in a state where the coil 430 is not energized, as shown in FIG. 5, the magnetic pole boundary surface BS of the rotor 410 is first opposed to the first magnetic pole portion 421. Since the surface 421b and the second opposing surface 422b of the second magnetic pole portion 422 are stopped at positions shifted from the intermediate positions, the N-pole outer peripheral surface 412a and the first magnetic pole portion 421 (first arc surface 421a, first arc A magnetic attraction force is generated between the S pole outer peripheral surface 412b and the second magnetic pole portion 422 (second arc surface 422a ', second counter surface 422b) between the opposing surfaces 421b), and the rotor 410 has a timepiece. Stops at the rotating end around and is held securely.
This state corresponds to a state in which the blade member 30 of the camera blade driving device is positioned at a position (open position) that is in contact with the stopper 17 and retracted from the openings 10a and 20a, as shown in FIG.

In this state, when the coil 430 is energized in a predetermined direction, an N pole is generated in the first magnetic pole portion 421 and an S pole is generated in the second magnetic pole portion 422.
Thereby, between the N pole outer peripheral surface 412a and the first magnetic pole portion 421 (first arc surface 421a, first opposing surface 421b), the S pole outer peripheral surface 412b and the second magnetic pole portion 422 (second arc surface 422a ', first Between the two opposing surfaces 422b), a repulsive force is generated by an electromagnetic force to generate a strong rotational torque, and the rotor 410 starts to rotate counterclockwise.
When the rotor 410 rotates counterclockwise, the interval between the N pole outer peripheral surface 412a and the second opposing surface 422b continuously changes, and the S pole outer peripheral surface 412b and the first opposing surface 421b Since the interval between them changes continuously, the rotor 410 rotates smoothly and quickly counterclockwise to generate a large rotational driving force (driving torque).

Then, as shown in FIG. 6, when the rotor 410 reaches the counterclockwise rotation end, S between the N pole outer peripheral surface 412 a and the second magnetic pole portion 422 (first arc surface 422 a and second opposing surface 422 b). Between the pole outer peripheral surface 412b and the first magnetic pole portion 421 (first arc surface 421a ′, first opposing surface 421b), an attractive force is generated by electromagnetic force so that the rotor 410 is further rotated counterclockwise. In a state where a strong rotational biasing force is generated.
In this state, if the coil 430 is de-energized, the electromagnetic attraction force changes to a strong magnetic attraction force, and the rotor 410 stops at the counterclockwise rotation end and is securely held. 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 18 and faces the openings 10a and 20a as shown in FIG.

On the other hand, when the coil 430 is energized in the reverse direction, opposite magnetic poles are generated in the first magnetic pole part 421 and the second magnetic pole part 422, respectively, and the rotor 410 rotates smoothly and quickly clockwise. A rotational driving force (driving torque) is generated.
At this time, in the blade driving device for a camera, the blade member 30 is moved from the position (closed position) that contacts the stopper 18 and faces the openings 10a and 20a as shown in FIG. 6 to the stopper 17 as shown in FIG. It moves and positions to the position (open position) which contact | abutted and retracted from opening part 10a, 20a.
When the coil 430 is de-energized, the rotor 410 is stopped and securely held at the rotational end in the clockwise direction by a strong magnetic attractive force.

  Thus, by providing the yoke 420 with the first opposing surface 421b and the second opposing surface 422b that continuously change the distance from the rotor 410 (the outer peripheral surfaces 412a, 412b thereof), the rotor 410 is smooth and quick. And a large rotational driving force (driving torque) can be generated, and the rotor 410 can be held at the stop position by a large magnetic holding force at both end positions (stop positions) of the operating range. In addition, when this electromagnetic actuator 400 is used as a drive source of the camera blade drive device, the blade member 30 can be driven smoothly and stably.

FIG. 7 shows a state in which the camera blade driving device M using the electromagnetic actuator 400 as a driving source is mounted on the mobile phone 500.
A mobile phone 500 includes a main body 510 provided with various operation buttons 510a, a cover 520 provided with a monitor 520a that is rotatably connected to the main body 510 and displays various information, and an outer surface of the cover 520. A camera blade driving device M and the like housed inside the formed photographing window 520b are provided.
As described above, the camera blade driving device M using the electromagnetic actuator 400 as a driving source can obtain a sufficient driving torque by the rotor 410 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. 8 and 9 show a camera blade drive device using an electromagnetic actuator 400 ′ as a drive source according to another embodiment of the present invention, and are the same as those in the previous embodiment except that the rotor 410 ′ is changed. Therefore, the same components as those of the above-described embodiment are denoted by the same reference numerals, and the description thereof is omitted.
In this electromagnetic actuator 400 ′, the rotor 410 ′ has an end surface 421 ′ of the first magnetic pole portion 421 and a second magnetic pole in the direction of the rotation axis L as shown in FIGS. 8 and 9A and 9B. A disc-shaped thrust formed by projecting in a radial direction from the outer peripheral surfaces 412a and 412b and magnetizing the same magnetic pole as the cylindrical magnetized portion 412 so as to face the end surface 422 ′ of the portion 422 A magnetized portion 414 is integrally provided.
The thrust magnetized portion 414 includes an N-pole magnetized portion 414a and an S-pole magnetized portion 414b with the magnetic pole boundary surface BS as a boundary.

According to this, as the magnetized portion of the rotor 410 ′, the thrust magnetized portion 414 (N-pole magnetized portion 414a, S-pole magnetized portion 414b) integrally formed on one end side of the cylindrical magnetized portion 412 is used. As a result, the thrust magnetized portion 414 faces the first magnetic pole portion 421 (the end surface 421 ′) or the second magnetic pole portion 422 (the end surface 422 ′) of the yoke 420 in the direction of the rotation axis L of the rotor 410 ′. As a result, the surface that exerts a magnetic action increases.
Therefore, when the coil 430 is not energized, the thrust magnetized portion 414 generates a strong magnetic attraction force between the first magnetic pole portion 421 or the second magnetic pole portion 422, and a stable holding force is obtained. During energization, the thrust magnetized portion 414 generates a strong repulsive force and attractive force due to electromagnetic force between the first magnetic pole portion 421 and the end surfaces 421 'and 422' of the second magnetic pole portion 422 in the rotation axis L direction. Thus, a desired rotational driving force (driving torque) and holding force can be generated.
Here, since the thrust magnetized portion 414 is integrally formed on one end side of the cylindrical magnetized portion 412, the required driving torque and magnetic attraction are achieved while achieving simplification and thinning of the structure. Force and repulsive force can be easily set.

FIG. 10 and FIG. 11 show a camera blade drive device using an electromagnetic actuator 400 ″ as a drive source according to still another embodiment of the present invention, and the above-described embodiment except that the rotor 410 ″ is changed. Since the configuration is the same as that of the embodiment, the same components as those of the above-described embodiment are denoted by the same reference numerals and description thereof is omitted.
In this electromagnetic actuator 400 ″, the rotor 410 ″ has both end surfaces 421 ′ and 421 ′ of the first magnetic pole portion 421 in the direction of the rotation axis L, as shown in FIGS. 10 and 11 (a) and 11 (b). 421 ″ and both end surfaces 422 ′ and 422 ″ of the second magnetic pole portion 422 are formed so as to protrude in the radial direction from the outer peripheral surfaces 412a and 412b and have the same magnetic pole as the cylindrical magnetized portion 412. Two disc-shaped thrust magnetized portions 414 and 415 formed by magnetizing are integrally provided.
The thrust magnetized portions 414 and 415 include N-pole magnetized portions 414a and 415a and S-pole magnetized portions 414b and 415b, respectively, with the magnetic pole boundary surface BS as a boundary.

According to this, as the magnetized portion of the rotor 410 ″, two thrust magnetized portions 414 (N-pole magnetized portion 414a, S-pole magnetized portion) integrally formed on both ends of the cylindrical magnetized portion 412 are used. 414b) and the thrust magnetized portion 415 (N-pole magnetized portion 415a, S-pole magnetized portion 415b), the thrust magnetized portions 414 and 415 are disposed in the yoke 420 in the direction of the rotation axis L of the rotor 410 ″. Opposite the first magnetic pole part 421 (both end faces 421 ′ and 421 ″ thereof) or the second magnetic pole part 422 (both end faces 422 ′ and 422 ″ thereof), the number of surfaces exerting a magnetic action increases.
Therefore, when the coil 430 is not energized, the thrust magnetized portions 414 and 415 generate a strong magnetic attractive force between the first magnetic pole portion 421 or the second magnetic pole portion 422, and a stable holding force is obtained. When the coil 430 is energized, the thrust magnetized portions 414 and 415 are between the first magnetic pole portion 421 or the end surfaces 421 ′, 421 ″, 422 ′, and 422 ″ of the second magnetic pole portion 422 in the rotation axis L direction. A strong repulsive force and attractive force due to electromagnetic force can be generated to generate a desired rotational driving force (driving torque) and holding force.
Here, since the thrust magnetized portions 414 and 415 are integrally formed on both ends of the cylindrical magnetized portion 412, the required driving torque and magnetic force are achieved while achieving simplification and thinning of the structure. The attractive suction force and repulsive force can be easily set.

In the above-described embodiment, the camera blade driving device adopting the electromagnetic actuators 400, 400 ′, 400 ″ according to the present invention as a driving source for driving one blade member 30 is shown, but the present invention is not limited to this. Instead, the electromagnetic actuator according to the present invention may be employed as a drive source for driving a blade member composed of two or more blades.
In the above embodiment, the case where the drive pins 413 of the rotors 410, 410 ′, and 410 ′ are formed of a member different from the magnetized portion is shown, but the present invention is not limited to this and is the same as the magnetized portion. The material may be integrally formed and magnetized to the same magnetic pole as the magnetized portion.
In the above embodiment, flat surfaces that are flat in the direction perpendicular to the center line C of the operating range of the magnetic pole boundary surface BS are employed as the first facing surface 421b and the second facing surface 422b provided on the yoke 420. However, the present invention is not limited to this, and it may be formed at other positions as long as the distance between the outer peripheral surfaces 412a and 412b of the rotor is changed continuously.

  As described above, the electromagnetic actuator of the present invention can generate a desired holding force and driving torque while achieving downsizing, so that it can be applied as a driving source of a camera blade driving device. This is also useful as a drive source for other optical equipment or electronic equipment that requires the driven member to reciprocate.

It is a front view which shows one Embodiment of 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, wherein (a) is a plan view and (b) is a partial cross-sectional view. It is the enlarged view to which a part of electromagnetic actuator mounted in the apparatus shown in FIG. 1 was expanded. 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 an expanded sectional view showing the blade drive device for cameras carrying the electromagnetic actuator concerning other embodiments of the present invention. FIG. 9 shows a part of the electromagnetic actuator mounted on the apparatus shown in FIG. 8, wherein (a) is a plan view and (b) is a partial cross-sectional view. It is an expanded sectional view showing the blade drive device for cameras carrying the electromagnetic actuator concerning other embodiments of the present invention. FIG. 11 shows a part of the electromagnetic actuator mounted on the apparatus shown in FIG. 10, in which (a) is a plan view and (b) is a partial cross-sectional view.

Explanation of symbols

10 Ground plane (substrate)
20 Back plate (substrate)
10a, 20a Exposure openings 11, 15 Support shaft 12 Through-holes 13, 14 Positioning protrusion 16 Protrusion 17, 18 Stopper 30 Blade member 400, 400 ', 400 "Electromagnetic actuator (drive source)
410, 410 ′, 410 ″ Rotor L Rotating shaft BS Magnetic pole boundary surface 411 Through hole 412 Cylindrical magnetized portion 412a N pole outer peripheral surface 412b S pole outer peripheral surface 413 Drive pins 414, 415 Thrust magnetized portions 414a, 415a N pole attached Magnetic part 414b, 415b S pole magnetized part 420 Yoke 421 First magnetic pole part 421a, 421a ′ First arc surface 421b First opposing surface 422 Second magnetic pole part 422a, 422a ′ Second arc surface 422b Second opposing surface 423 Positioning Hole 430 Excitation coil 440 Presser plate 441 Bobbin 441a, 442, 443 Fitting hole 500 Mobile phone 510 Main body 520 Lid 520b Shooting window M Camera blade drive device

Claims (8)

A rotor including a cylindrical magnetized portion that defines an outer circumferential surface magnetized in the circumferential direction and capable of rotating within a predetermined angular range, an excitation coil, and a first coil that faces the outer circumferential surface of the rotor with a predetermined interval. An electromagnetic actuator comprising a yoke having a first magnetic pole part and a second magnetic pole part, each defining a first arc surface and a second arc surface and generating different magnetic poles by energizing the coil,
The first magnetic pole part and the second magnetic pole part are formed continuously on the first arc surface and the second arc surface, respectively, and are formed so as to continuously change an interval facing the outer peripheral surface of the rotor. Having a first facing surface and a second facing surface,
An electromagnetic actuator characterized by that. The first facing surface and the second facing surface are formed point-symmetrically with respect to the rotation axis of the rotor.
The electromagnetic actuator according to claim 1. The first facing surface and the second facing surface are formed as flat surfaces that are flat in a direction perpendicular to the center line of the operating range of the magnetic pole boundary surface of the rotor,
The electromagnetic actuator according to claim 1, wherein the electromagnetic actuator is characterized in that The rotor is formed so as to protrude in the radial direction from the outer peripheral surface so as to face the first magnetic pole part and the second magnetic pole part in the direction of the rotation axis, and is attached to the same magnetic pole as the cylindrical magnetized part. Including a thrust magnetized portion formed by magnetism,
The electromagnetic actuator according to any one of 1 to 3, wherein The thrust magnetized portion is integrally formed on one end side of the cylindrical magnetized portion,
The electromagnetic actuator according to claim 4. The thrust magnetized portion is integrally formed on both end sides of the cylindrical magnetized portion,
The electromagnetic actuator according to claim 4. The thrust magnetized portion is formed in a disk shape having a diameter larger than the diameter of the cylindrical magnetized portion.
The electromagnetic actuator according to claim 5 or 6, characterized by the above. 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 7,
A blade drive device for a camera.

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