JP3295168B2 - Moving magnet motor for camera - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moving magnet motor used for a camera shutter or the like.

[0002]

2. Description of the Related Art Conventionally, as a moving magnet motor, there has been known a moving magnet motor in which a magnetic circuit is formed by applying a winding to a plurality of locations on the outer periphery of a rotor having a permanent magnet to form a coil.

[0003]

However, in the moving magnet motor as described above, the rotor is set at the center of the motor and then the outer periphery thereof is wound.
A coil frame having coil winding portions at a plurality of locations is required, and there is a problem that the efficiency of assembly is low, it takes time, and the cost is high.

Further, the above-mentioned moving magnet motor has a large space for winding the outer periphery of the magnet, making it difficult to reduce the size of the moving magnet motor. For this reason, in the case where the shutter is used for a camera for which there is much need for miniaturization in recent years, there is a problem that the camera cannot be miniaturized because the shutter cannot be reduced in thickness.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and does not require a coil frame, can be efficiently assembled in a short time, can be obtained at low cost, and can be reduced in size.
It is an object of the present invention to provide a moving magnet motor that can be reduced in thickness.

[0006]

SUMMARY OF THE INVENTION A moving magnet motor for a camera according to the present invention has at least a structure perpendicular to a rotation axis.
Rotatable with multiple poles magnetized on one end
A rotor and a coil are mounted and provided on the rotor side.
At least one of the magnetic pole portions is disposed close to the end face.
And one yoke .

[0007]

In the moving magnet motor of the present invention, the yoke is excited by energizing the coil, and the rotor is rotated by the attraction / repulsion action between the magnetic pole portion of the yoke and the magnetic pole of the rotor.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the moving magnet motor according to the present invention will be described below with reference to FIGS.

As shown in FIGS. 1 and 2, the moving magnet motor of this embodiment has a rotor 1 having permanent magnets, a circular shape in plan view, a U-shaped yoke 2, and one of the yokes 2. Coil 3 with winding wound around leg
And the magnetic pole portions 4 at both ends of the yoke 2,
4 is arranged close to the end face of the rotor 1. The rotor 1 is magnetized on its end face such that at least two poles are arranged around the rotation axis. For example, at least two permanent magnets are placed on the outer circumference of a cylindrical rotor and the magnetic poles on the end face are adjacent to each other. The permanent magnets may be configured to be differently mounted with matching permanent magnets, or at least two permanent magnets may be arranged on the end face of the cylindrical rotor around the rotation axis so that the magnetic poles on the end face are different between adjacent permanent magnets. Attached and configured.

In this moving magnet motor, the yoke 2 is excited by energizing the coil 3, and the rotor 1 is rotated by the attraction / repulsion action between the magnetic pole portions 4, 4 at both ends of the yoke 2 and the magnetic poles of the rotor 1. .

Next, an example of a camera shutter using the moving magnet motor of this embodiment will be described with reference to FIG.

As shown in FIG. 3, this camera shutter comprises a base plate 10 on which a moving magnet motor M of the first embodiment is mounted, and two light-shielding blades 12, 12 for opening and closing an aperture O. The light-shielding blades 12 and 12 are attached so as to be swingable about
Slots 13 and 13 are formed in the
The driving pin 14 of the moving magnet motor M is engaged with the light-shielding blade 13, and the driving pin 14 drives the light-shielding blade 12,
12 swings.

In this embodiment, the yoke 2 is orthogonal to the rotation axis of the rotor 1, but the yoke 2 may be inclined as shown in FIG. In this embodiment, the number of the yokes 2 is one and the two magnetic pole portions 4 and 4 are close to one end face of the rotor 1. However, two yokes 2 are provided and the two yokes 2 The two magnetic pole parts 4, 4 may be made to approach one end face of the rotor 1, and the two magnetic pole parts 4, 4 of the other yoke 2 may be made close to the other end face of the rotor 1. In that case, the rotor 1 is magnetized such that at least two poles are arranged on both end faces around the rotation axis.

Next, a moving magnet motor according to a second embodiment of the present invention will be described with reference to FIGS.

As shown in FIGS. 5 and 6, the moving magnet motor of this embodiment is configured such that the magnetic pole portion 4 at one end of a bar-shaped yoke 2 is close to the end face of the rotor 1. Is wound with a coil 3.
The rotor 1 is magnetized so that at least two poles are arranged around the rotation axis on the end face, as in the first embodiment.

In this moving magnet motor, the yoke 2 is excited by energizing the coil 3, and the rotor 1 is attracted and repelled by the magnetic pole portion 4 of the yoke 2 close to the end face of the rotor 1 and the magnetic pole of the rotor 1. Rotates.

In this embodiment, as shown in FIG. 4, the yoke 2 may be inclined as in the first embodiment. In this embodiment, the number of the yokes 2 is one and the magnetic pole part 4 is close to one end face of the rotor 1. However, two yokes 2 are provided, and the magnetic pole part 4 of one yoke 2 is connected to the rotor 1. 1
And the magnetic pole part 4 of the other yoke 2 may be made to approach the other end face of the rotor 1.
In that case, the rotor 1 has at least two
The poles are magnetized such that they are arranged around the axis of rotation.

Next, a third embodiment of the moving magnet motor according to the present invention will be described with reference to FIGS.

As shown in FIGS. 7 and 8, the moving magnet motor of this embodiment is provided with two U-shaped yokes 2 similar to the first embodiment, and the two magnetic pole portions 4 of one yoke 2 are provided. , 4 are opposed to the magnetic pole portions 4, 4 of the other yoke 2, and all the magnetic pole portions 4, 4, 4, 4 are brought close to the end face of the rotor 1. The coil 3 is wound around one of the legs. The rotor 1 is
As in the first embodiment and the second embodiment, at least two poles are magnetized on the end face thereof so as to be arranged around the rotation axis. desirable.

In this moving magnet motor, the coils 3, 3 are energized to excite the yokes 2, 2, and the magnetic pole portions 4, 4, 4, at both ends of the yokes 2, 2 are excited.
4 and the magnetic poles of rotor 1
Rotates.

In this embodiment, as shown in FIG. 9, the yokes 2 and 2 may be inclined similarly to the first and second embodiments. In this embodiment, all the magnetic pole portions 4, 4, 4, 4 of the two yokes 2, 2 are close to one end face of the rotor 1. However, four yokes 2 are provided, and two yokes 2 are provided. 2 and 2, the magnetic pole portions 4, 4, 4, 4 are brought close to one end face of the rotor 1, and the remaining two yokes 2,
The two magnetic pole parts 4, 4, 4, 4 may be brought close to the other end face of the rotor 1. In this case, the rotor 1 is magnetized such that at least two poles are arranged on both end faces thereof around the rotation axis.

Next, a fourth embodiment of the moving magnet motor according to the present invention will be described with reference to FIGS.

In the moving magnet motor of this embodiment, as shown in FIGS. 10 and 11, the central magnetic pole portions 4, 4 of the two longitudinal portions of the rectangular frame-shaped yoke 2 are brought close to the end face of the rotor 1. The yoke 2
The coil 3 is wound around each of the two short portions. The rotor 1 is magnetized such that at least two poles are arranged around the rotation axis on its end face, as in the first to third embodiments.

In this moving magnet motor, the yoke 2 is excited by energizing the coils 3 and 3,
The rotor 1 is rotated by the attraction / repulsion between the two magnetic pole portions 4 and 4 of the yoke 2 and the magnetic poles of the rotor 1.

In this embodiment, there is one yoke 2 and its two magnetic pole portions 4 and 4 are close to one end face of the rotor 1. However, two yokes 2 are provided and one yoke 2 is provided. The two magnetic pole portions 4, 4 of the two yokes 2 may be made to approach one end face of the rotor 1, and the two magnetic pole portions 4, 4 of the other yoke 2 may be made close to the other end face of the rotor 1. In that case, the rotor 1 is magnetized such that at least two poles are arranged on both end faces around the rotation axis.

Next, a fifth embodiment of the moving magnet motor of the present invention will be described with reference to FIG.

In the moving magnet motor of this embodiment, as shown in FIG. 12, one yoke 2 having two magnetic poles 4, 4 is formed by branching one end of an iron core 5.
2 are arranged such that all the magnetic pole portions 4, 4, 4, 4 are close to the end face of the rotor 1.
Are wound with coils 3 respectively. The rotor 1 is
As in the first to fourth embodiments, at least two poles are magnetized on its end face so as to be arranged around the rotation axis. However, it is possible to use a magnet having four poles magnetized. desirable.

In this moving magnet motor, the coils 3, 3 are energized to excite the yokes 2, 2, and the magnetic poles 4, 4, 4, 4 of these yokes 2, 2 and the magnetic poles of the rotor 1 are attracted. -The rotor 1 rotates by the repulsive action.

In this embodiment, the yokes 2 and 2 may be inclined as in the first to third embodiments.
In this embodiment, all the magnetic pole portions 4, 4, 4, 4 of the two yokes 2, 2 are close to one end face of the rotor 1. However, four yokes 2 are provided, and two yokes 2 are provided. The two magnetic pole portions 4, 4, 4, 4 are brought close to one end face of the rotor 1, and the magnetic pole portions 4, 2,
4, 4, 4 may be made to approach the other end face of the rotor 1. In this case, the rotor 1 is magnetized such that at least two poles are arranged on both end faces thereof around the rotation axis.

Further, in this embodiment, the two magnetic pole portions 4, 4 of each yoke 2 are brought close to the same end face of the rotor 1, but as shown in FIG.
4 may be brought close to different end faces of the rotor 1 respectively.

[0031]

According to the moving magnet motor of the present invention, the magnetic pole portion of the yoke on which the coil is mounted is arranged close to the end face of the rotor having the permanent magnet.
Since a coil frame is not required, it can be assembled efficiently in a short time, can be obtained at low cost, and can be reduced in size and thickness. For this reason, when this moving magnet motor is used as a blade drive device of a camera shutter, the whole of the shutter device can be made thinner, whereby the camera can be downsized. Very useful in cases.

[Brief description of the drawings]

FIG. 1 is a plan view of a moving magnet motor according to a first embodiment of the present invention.

FIG. 2 is a front view of the moving magnet motor of FIG.

FIG. 3 is a plan view showing an example of a camera shutter using the moving magnet motor of the first embodiment.

FIG. 4 is a front view of a moving magnet motor in which a yoke is inclined in the first and second embodiments.

FIG. 5 is a plan view of a moving magnet motor according to a second embodiment of the present invention.

FIG. 6 is a front view of the moving magnet motor of FIG . 5 ;

FIG. 7 is a plan view of a moving magnet motor according to a third embodiment of the present invention.

FIG. 8 is a front view of the moving magnet motor of FIG . 7 ;

FIG. 9 is a front view of a moving magnet motor in which a yoke is inclined in the third embodiment.

FIG. 10 is a plan view of a moving magnet motor according to a fourth embodiment of the present invention.

FIG. 11 is a front view of the moving magnet motor of FIG . 10 ;

FIG. 12 is a plan view of a moving magnet motor according to a fifth embodiment of the present invention.

FIG. 13 is a front view of a moving magnet motor in which two magnetic pole portions of a yoke are brought close to another end surface of a rotor in a fifth embodiment.

[Explanation of symbols]

 1 rotor 2 yoke 3 coil 4 magnetic pole

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-166532 (JP, A) JP-A-63-31463 (JP, A) JP-A-56-58754 (JP, A) 184993 (JP, U) WO 92/22122 (WO, A1) (58) Fields investigated (Int. Cl. ⁷ , DB name) H02K 33/16 H02K 37/16 G03B 9/24

Claims (1)

(57) [Claims] At least one end face orthogonal to a rotation axis
A rotatable rotor having a plurality of magnetic poles magnetized on,
A magnetic pole portion provided with a coil and provided on the rotor side
At least one of the at least one
A yoke and a camera
Moving magnet motor.