JPH1031240A - Movable magnet type oscillation actuator for variable vertex angle prism device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify the structure, to reduce the number of parts and to miniaturize and make thin an oscillation actuator by shifting a variable vertex angle prism with a movable magnetic body operated by electromagnetic force between the magnet body and a fixed coil body. SOLUTION: The movable magnetic type oscillation actuator 20 is provided with the movable magnet body 21 of a hollow cylindrical shape (cylindrical ring shape) and the fixed coil body 30 oscillating the movable magnet body 21 nu yhr electromagnetic force. The hollow cylindrical shape movable magnet body 21 is stuck to an outer peripheral side of a hollow cylindrical shape hold body 23 formed by non-magnet material such as resin, etc., by adhesive, etc. Further, the hold body 23 is a member for integrally holding and sticking the glass plate of the variable vertex angle prism. When a drive current is made flow through the driving coil 32 of the fixed coil body 30, since magnetic flux by the movable magnetic body 21 being a permanent magnetic with two pole magnetization applied on its outer peripheral surface crosses the driving coil 32, the electromagnetic force occurs between the movable magnetic body 21 and the coil 32, and the movable magnetic body 21 is oscillated around an oscillation central axis P.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a movable magnet type oscillating actuator for a variable apex angle prism device provided for changing a traveling direction of a passing light beam in an optical system such as a video camera, and more particularly to a variable apex angle prism. The movable magnet body is fixed to at least one of the transparent members, and the movable member is oscillated by electromagnetic force between the movable member and the fixed coil body to change the direction of the passing light beam. It relates to a dynamic actuator.

[0002]

2. Description of the Related Art In recent years, camera devices such as video cameras have been automated, and various functions such as automatic exposure adjusting means and automatic focus adjusting means have been put to practical use. As one of these automation functions, blur correction means for reducing harmful blurring of a screen caused by various causes has been proposed, the main one of which is formed on an image sensor using a variable apex prism device. Japanese Patent Laid-Open Publication No.
90398.

The image blur correction device disclosed in Japanese Patent Application Laid-Open No. Hei 6-90398 uses a variable apex angle prism device as a means for optically correcting the blur of an optical image formed by an objective lens such as a video camera. The specific configuration is shown in FIG.

The conventional variable apex angle prism device shown in FIG.
It is mainly composed of a variable apex angle prism 1, a moving coil type linear actuator 10 for driving the same, and an apex angle sensor unit 16 for detecting an angle state of the variable apex angle prism 1. In FIG. 11, reference numeral 1 denotes a variable apex prism, which is formed by integrally bonding transparent glass plates 3 on both sides of a bellows 2 in a watertight manner, and filling the inside with a transparent liquid such as silicon oil. The transparent glass plates 3 on both sides of the bellows 2 are integrally attached to the glass holders 4A and 4B by bonding or the like, respectively.
It is freely swingable (reciprocating rotary movement is possible) around the swing shafts 5A and 5B shifted by degrees. In order to drive the glass holder 4A, the moving coil type linear actuator 10 is used.
Is provided. The movable coil 11 of the linear actuator 10 is fixed to the glass holder 4A side and rotates integrally with the glass holder 4A. On the magnetic yoke 13 side to which the field permanent magnet 12 is fixed, a variable apex prism device is installed. It is fixedly supported by a video camera or the like. Further, a vertex angle sensor unit 16 is provided for detecting the tip position of the arm 15 integrally extending from the glass holder 4A to thereby know the shift state of the variable vertex prism. In addition,
Although the illustration of the linear actuator on the side of the glass holder 4B is omitted, the linear actuator is swingably driven in the same configuration as that of the glass holder 4A except that the mounting direction is different by 90 degrees.

[0005]

As described above, when prevention of camera shake or the like is performed optically by a variable apex angle prism, it is necessary to correspond to any angle. The movable-coil linear actuator 10 having a linear motion axis perpendicular to the glass surface with the direction in which the front glass surface and the rear glass surface of the variable apex angle prism 1 are shifted by 90 degrees from each other as a rotation axis. Although it has a structure that can be operated, it has the following problems to be solved.

(1) Since the variable apex angle prism 1 is driven by the movable coil type linear actuator 10, a flexible wire or the like for energizing the movable coil 11 is required, which hinders durability and the like. May occur.

(2) The movable movable coil type linear actuator 10 is disposed at right angles to the prism surface of the variable apex angle prism 1, ie, the outer surface of the glass plate 3, so that the variable apex angle prism device is downsized. It is difficult to reduce the thickness.

(3) In practice, parts and the like for jointing the variable apex angle prism 1 and the movable coil type linear actuator 10 for driving are required, and the number of parts is increased, and it is difficult to reduce the cost.

In view of the above, the present invention has a structure in which a variable apex angle prism is shifted by a movable magnet body operated by an electromagnetic force between the fixed coil body, thereby eliminating the need for a flexible wire or the like. It is an object of the present invention to provide a movable magnet type oscillating actuator for a variable apex angle prism device capable of simplifying the structure, reducing the number of parts, and further reducing the size and thickness.

[0010] Other objects and novel features of the present invention will be clarified in embodiments described later.

[0011]

SUMMARY OF THE INVENTION To achieve the above object, the present invention provides a variable apex angle variable prism which moves at least one transparent member to change the direction of a light beam passing through the variable apex angle prism. A movable magnet type swing actuator for a square prism device, comprising: a movable magnet body fixed to the transparent member so as to pass at least most of the light beam; and a fixed magnet at a position where at least most of the light beam passes. And a fixed coil body that swings the movable magnet body by an electromagnetic force.

Further, in the movable magnet type swing actuator for a variable apex angle prism device, the movable magnet body has a hollow shape and is magnetized in a radial direction, and one side of the movable magnet body with respect to the swing center axis. The magnetizing directions of the fixed coil body and the other side may be opposite to each other, and the fixed coil body may have a driving coil wound around the inside or outside of the movable magnet body. Alternatively, the movable magnet body has a hollow shape and is longitudinally magnetized, and the fixed coil body is wound around the inside or outside of the movable magnet body, and the N of the movable magnet body is A configuration having a first driving coil near the pole and a second driving coil near the south pole may be employed.

Further, the fixed coil body may have a speed detecting coil.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a movable magnet type swing actuator for a variable apex angle prism device according to the present invention will be described below with reference to the drawings.

1 and 2 show a first embodiment of a movable magnet type oscillating actuator for a variable apex angle prism device, FIG. 3 shows a magnetic circuit thereof, and FIG. 4 shows a movable magnet body. . FIG. 5 is an exploded perspective view when a variable apex angle prism and a movable magnet type swing actuator are combined to form a variable apex angle prism device, and FIGS. 6 and 7 are side sectional views for explaining the operation. .

First, a first embodiment of a movable magnet type swing actuator for a variable apex angle prism device will be described with reference to FIGS. In these figures, reference numeral 20 denotes a movable magnet type swing actuator for a variable apex angle prism device, which is fixed to a movable magnet body 21 having a hollow cylindrical shape (cylindrical ring shape) so as to swing the movable magnet body 21 by electromagnetic force. And a coil body 30.

As shown in FIGS. 3 and 4 (and, if necessary, FIG. 5 showing the entire variable apex angle prism apparatus), the hollow cylindrical movable magnet body 21 is made of a permanent magnet material powder in a resin, for example. A bonded magnet that is mixed, molded and magnetized into a hollow cylindrical shape, magnetized in the radial direction so as to have two poles on the outer peripheral surface, and has one side and the other side of the swing center axis P. The magnetization directions are opposite. For example, in FIG. 4, the outer peripheral surface of the movable magnet body on the left side of the swing center axis P has an N pole, and the inner peripheral surface has
A pole is formed, and an S pole is formed on the outer peripheral surface of the movable magnet body on the right side of the swing center axis P, and an N pole is formed on the inner peripheral surface. The hollow cylindrical movable magnet body 21 is fixed to the outer peripheral side of a hollow cylindrical holder 23 made of resin (non-magnetic material) or the like with an adhesive or the like, and is fitted into the holder 23 as shown in FIG. The swinging shaft 22 penetrates the movable magnet body 21 and protrudes from the outer peripheral surface thereof. The fixed position of the oscillating shaft 22 is a position coinciding with the oscillating center axis P of the movable magnet body 21 shown by a dashed line in FIGS. The holding member 23 is a member for integrally holding and fixing a glass plate of a variable apex angle prism described later with reference to FIGS.

The fixed coil body 30 is shown in FIGS.
As shown in FIG. 5, a driving coil 32 is wound around a resin bobbin 31 having a flange portion 31b on both sides of a cylindrical portion 31a, and a position crossing the cylindrical portion 31a in the diameter direction as shown in FIG. A bearing 33 for rotatably supporting the oscillating shaft 22 is disposed on the shaft portion and fixed to the cylindrical portion 31a. Therefore, as shown in FIG. 1 and FIG.
In a state in which the movable magnet body 21 and the fixed swing shaft 22 are rotatably fitted to the holding body 23 side in the 0-side bearing 33,
The driving coil 32 is wound around the outer peripheral side of the movable magnet body 21. Further, a speed detection coil 34 is wound around the driving coil 32 so as to be superimposed thereon. Both the drive coil 32 and the speed detection coil 34 have an air-core coil structure having no magnetic core.

Incidentally, two pairs of external connection terminals 35 and 36 are implanted in the flange 31b of the resin bobbin 31.
The leading end of the driving coil 32 is connected to the pair of external connection terminals 35, and the leading end of the speed detection coil 34 is connected to the external connection terminal 36.

A magnetic yoke 40 made of a soft magnetic material passes through the swing center axis P (passes through the two swing shafts 22) so as to cover the outer peripheral portion and a part of the side surface of the resin bobbin 31 of the fixed coil body 30. Are fixedly arranged symmetrically. As shown in the magnetic circuit of FIG. 3, the magnetic yoke 40 increases the magnetic flux linked with the driving coil 32 among the magnetic fluxes generated by the movable magnet body 21.
And a magnetic shield. The magnetic yoke 40 is ideally provided over the entire circumference of the fixed coil body 30. However, at least the portion where the external connection terminals 35 and 36 for connecting the lead wires for power supply and the like are cut or the like. Provide and avoid.

As can be seen from the magnetic circuit shown in FIG. 3, the movable magnet type swing actuator 2 for the variable apex angle prism device is used.
When a drive current is applied to the drive coil 32 of the fixed coil body 30 included in the drive coil 0, the magnetic flux from the movable magnet body 21 which is a permanent magnet having a two-pole magnetized outer peripheral surface is linked to the drive coil 32. Then, an electromagnetic force (force according to Fleming's left hand rule) is generated between the movable magnet body 21 and the coil 32, and the movable magnet body 21 can swing about the swing center axis P. The thrust in the swing direction indicated by the arrow in FIG. If the direction of the current flowing through the driving coil 32 is reversed, the direction of the thrust is also reversed.

Further, since the induced voltage corresponding to the swing speed of the movable magnet 21 is generated in the speed detecting coil 34, the swing speed of the movable magnet 21 can be detected.

Next, an overall configuration of a variable apex angle prism device using two movable magnet type swing actuators 20 for the variable apex angle prism device will be described with reference to FIGS. In these figures, reference numeral 1 denotes a variable apex prism, and a transparent glass plate 3 as a transparent member forming a prism surface is water-tightly joined and integrated on both sides of a flexible resin bellows 2 and a transparent material such as silicon oil is internally provided. A liquid is enclosed. Bellows 2
The transparent glass plate 3 on the left side of the figure is attached to a hollow cylindrical holder 23 which is a movable part of the movable magnet type swinging actuator 20-1 for the first variable apex angle prism device so as to be driven by the first variable apex prism device. Similarly, the transparent glass plate 3 on the right side of the bellows 2 is fixed to the movable magnet type swing actuator 2 for the second variable apex angle prism device by an adhesive or the like.
0-2 to be driven by the actuator 20-2.
Are fixed integrally to the hollow cylindrical holder 23, which is a movable part, with an adhesive or the like. Here, the swing center axis S- of the movable portion (the movable magnet body 21 and the holding body 23) of the movable magnet type swing actuator 20-1 for the first variable apex angle prism device.
The swing center axes S-2 of the movable portions (the movable magnet body 21 and the holder 23) of the movable magnet type swing actuator 20-2 for the first and second variable apex angle prism devices are shifted from each other by 90 degrees, Shake correction in all directions is possible. Also, each of the actuators 20-1 and 20-20 does not substantially hinder the progress of the light beam passing through the variable apex angle prism 1.
The second hollow cylindrical holder 23 holds an outer peripheral portion of the circular transparent glass plate 3 located outside the passing light beam. Since the movable magnet body 21 is located on the outer peripheral side of the holding body 23 and the fixed coil body 30 is further located outside the holding body 23, the traveling of the light flux is not hindered.

The movable magnet type swing actuators 20-1 and 20-2 for the first and second variable apex angle prism devices.
The fixed coil body 30 is fixedly supported by a video camera or the like provided with a variable apex angle prism device.

In the variable apex angle prism device shown in FIGS. 5 to 7, the drive coils 32 of the movable magnet type swing actuators 20-1 and 20-2 for the left and right variable apex angle prism devices are energized, for example, as shown in FIG. As shown in FIG. 7, the movable magnet body 21 and the holding body 23, which are the movable parts, are pivoted about the swing center axis S-.
1 and S-2, and the transparent glass plate 3 constituting the prism surface of the variable apex angle prism 1 integrated with the movable portion can be swung. By changing the swing shift amount of the plate 3, it is possible to bend the light beam and correct the blur of the light beam in an arbitrary direction. FIG. 6 shows a state in which the prism surfaces, which are the outer surfaces of the transparent glass plates 3 on both sides, are parallel to each other and allow the light beam to pass straight (the both actuators 20-1 and 20-2 are not energized). .

According to the first embodiment, the following effects can be obtained.

(1) The movable magnet type oscillating actuator 20 for the variable apex angle prism device comprises a movable magnet 21 and a holder 2
3 is a movable portion, and the drive coil 32 which needs to be energized may be wound around the fixed coil body 30 side, which is necessary in the case of a movable coil type linear actuator used for a conventional variable apex prism apparatus. Is not required, the structure is simple, and there is no problem in durability even in long-term use.

(2) The movable magnet type oscillating actuator 20 for the variable apex angle prism device has a hollow cylindrical shape (ring shape) outside the glass plate 3 as a transparent member forming the prism surface of the variable apex angle prism 1. ), And the glass plate 3 may be fixed to the movable portion (the movable magnet body 21 and the holder 23) of the actuator 20. Therefore, the variable apex angle is changed as in the case of using the conventional movable coil type linear actuator. There is no large protrusion on the outside of the prism 1, and the size and thickness can be reduced.

(3) The holding member 23 which is the movable part of the movable magnet type swing actuator 20 for the variable apex angle prism device can be directly and integrally fixed to the glass plate 3 as a transparent member forming the prism surface of the variable apex angle prism 1. , Can be directly driven without the use of a joint or the like. In this regard, the mechanism can be simplified, the number of parts can be reduced, and the loss of thrust is small.

(4) A holder 23 which is a movable part of the movable magnet type swing actuator 20 for the variable apex angle prism device may be fixed to the outer periphery of the light beam passing through the transparent glass plate 3 on both sides of the variable apex angle prism. , Movable magnet 21 and holder 2
By making 3 a hollow cylindrical shape (ring shape) conforming to the shape of the transparent glass plate 3, the transparent glass plate 3 can be driven to swing without substantially hindering the progress of the light beam passing through the variable apex angle prism 1.

(5) The movable magnet body 21 has a hollow shape (ring shape) and is magnetized in the radial direction, and the magnetizing direction is shifted between one side and the other side with respect to the swing center axis. Since the structure is such that one driving coil 32 is wound around the fixed coil body 30 around the outside of the movable magnet body 21, the same is applied to the left and right sides of the movable magnet body 21. A thrust in the rotating direction can be generated, and a large thrust can be generated with a simple magnetic circuit.

(6) Since the speed detecting coil 34 is added to the fixed coil body 30, a detection signal corresponding to the swing speed of the movable magnet body 21 can be obtained.

FIGS. 8 and 9 show a second embodiment of a movable magnet type swing actuator for a variable apex angle prism device according to the present invention. The movable magnet type oscillating actuator 20A for the variable apex angle prism device in this case has the same mechanical structure as the movable magnet type oscillating actuator 20 for the variable apex angle prism device described above, but has a different magnetic circuit. .
That is, the movable magnet body 21A having a hollow cylindrical shape is magnetized in the length direction (axial direction of the hollow cylindrical shape), and an N pole is formed on one end face or end, and an S pole is formed on the other end face or end. Have been. However, the magnetization directions are opposite to each other on the left and right sides of the swing center axis P (so-called double-sided two-pole magnetization). Further, the fixed coil body 30A is
A first driving coil 32 close to and surrounding the north pole of A
A and the second driving coil 3 close to and surrounding the south pole
2B, and these coils 32A and 32B are connected so that currents flow in opposite directions. The other components may be the same as those of the movable magnet type swing actuator 20 for the variable apex angle prism device shown in the first embodiment. However, the side surface portion of the magnetic yoke 40 is unnecessary, and the illustration of the speed detection winding is omitted.
What is necessary is just to overlap and wind on either or both of 2A and 32B.

In the movable magnet type oscillating actuator 20A for the variable apex angle prism device, the fixed coil body 30A
The first and second driving coils 32A, 32B are supplied with currents of opposite directions to each other, so that the movable magnet body 2 which is a permanent magnet having magnetic poles formed on both end surfaces (or both end portions) is formed.
Electromagnetic force (force according to Fleming's left-hand rule) is generated between the movable magnet body 1A and the movable magnet body 1A. Each drive coil 32
The thrusts in the swinging directions by A and 32B are generated in a direction in which the thrusts are applied to each other. By reversing the direction of the current to be supplied, a thrust in the opposite direction can be generated. Therefore, even when the movable magnet type swing actuator 20A for the variable apex angle prism device is used,
As shown in FIGS. 5 to 7, the holding member 23 is fixedly attached to the transparent glass plate 3 of the variable apex angle prism 1 so that the variable apex angle prism 1 is swung in the same manner as in the first embodiment. be able to.

According to the movable magnet type oscillating actuator 20A for a variable apex angle prism device, the movable magnet body 21A having a hollow cylindrical shape only needs to be magnetized in the longitudinal direction (axial direction of the hollow cylindrical shape). There is an advantage that it can be easily magnetized even in the case of a sintered sintered magnet.

In each of the above embodiments, the case where the whole of the movable magnet body 21 or 21A is a hollow cylindrical (cylindrical ring) permanent magnet such as a bonded magnet or a sintered magnet has been described. The whole does not have to be constituted by permanent magnets. Also, the outer shape of the movable magnet bodies 21 and 21A is not limited to the hollow cylindrical shape but may be a hollow rectangular tube shape or the like. In short, various hollow shapes (cylindrical, The shape is not limited to a square tube shape, but may be any shape as long as it is a closed ring (ring shape).

FIG. 10 shows a modified example of a movable magnet body that can be used in the movable magnet type swing actuator for a variable apex angle prism apparatus according to the present invention. FIG. 10A shows a movable magnet body similar to the movable magnet body 21 or 21A. The entire movable magnet body is formed as a permanent magnet having a hollow rectangular tube shape (square tube ring shape) such as a bonded magnet or a sintered magnet so as to have a magnetic pole arrangement. FIG. 10 shows a magnetic pole arrangement similar to that of the movable magnet body 21 or 21A.
As shown in (B), (C), and (D), a movable magnet body may be configured by embedding a permanent magnet in a part of a resin having a hollow cylindrical shape or a hollow rectangular cylindrical shape (cylindrical ring or rectangular cylindrical ring shape). . However,
FIG. 10 (B) shows a case where a pair of arc-shaped permanent magnets are embedded in a hollow cylindrical resin, and FIG. 10 (C) shows a case where a pair of square rods or square plate permanent magnets are embedded in a hollow cylindrical resin. FIG. 10D shows a case where a pair of square rods or square plate-shaped permanent magnets is embedded in a hollow square tube-shaped resin. Further, in these cases, it is also possible to integrally form the holding body to form a movable magnet that also serves as the holding body.

Further, the swing shaft 22 of the movable magnet type swing actuator 20, 20A for the variable apex angle prism device.
The bearing 33 for receiving is provided on the inner peripheral portion (bobbin cylindrical portion 31a) of the fixed coil bodies 30, 30A, but a bearing mounting portion is formed on a side surface portion (bobbin flange portion 31b), and the bearing mounting portion is provided with a bearing. It is also possible to adopt a structure in which 33 is fixed. However, also in this case, it is necessary to set so that the positional relationship between the movable magnet bodies 21 and 21A and the driving coil does not change.

Further, in each of the above embodiments, the fixed coil bodies 30 and 30A surround the outside of the movable magnet bodies 21 and 21A, but the fixed coil body is located inside the movable magnet bodies 21 and 21A. This is also possible on the principle of operation. However, the movable magnet bodies 21 and 21A and the fixed coil bodies 30 and 3
0A needs to be arranged so that at least most of the light beam passing through the variable apex angle prism 1 can pass therethrough, and the fixed coil body may partially block the light beam passing through the variable apex angle prism 1. .

Although the embodiments of the present invention have been described above, it is obvious to those skilled in the art that the present invention is not limited to the embodiments and various modifications and changes can be made within the scope of the claims. There will be.

[0041]

As described above, according to the movable magnet type oscillating actuator for the variable apex angle prism apparatus according to the present invention, the variable apex angle prism is so formed as to pass at least most of the light beam of the variable apex angle prism. A structure in which a movable magnet body is fixed to a transparent member forming a prism surface, and the movable magnet body is rocked by an electromagnetic force between the movable coil body and a fixed coil body fixedly arranged at a position where at least most of the light flux passes. As a result, the flexible wire required for the moving coil type linear actuator used for the conventional variable apex angle prism device is unnecessary, the structure is simple, and there is no problem in durability even in long-term use. .

The movable magnet body and the fixed coil body may be arranged so as to surround the outside of the transparent member of the variable apex angle prism in a ring shape, and the movable magnet body including the movable magnet body of the actuator may be provided. Since the transparent member only needs to be fixed to the portion, a large protruding portion does not occur outside the variable apex angle prism as in the case of using the conventional moving coil type linear actuator, so that the size and thickness can be reduced.

Further, the transparent member can be directly driven without the intervention of a joint or the like.
The number of parts can be reduced, and a mechanism with little loss of thrust can be provided.

[Brief description of the drawings]

FIG. 1 is a plan view, partly in section, of a first embodiment of a movable magnet type swing actuator for a variable apex angle prism device according to the present invention.

FIG. 2 is a front view partially showing the same section.

FIG. 3 is a cross-sectional view illustrating a magnetic circuit according to the first embodiment.

FIG. 4 is a front view showing the magnetic pole arrangement (magnetization direction) of the movable magnet body used in the first embodiment.

FIG. 5 shows a variable apex prism and a movable magnet type swing actuator 2 for a variable apex prism apparatus according to the first embodiment.
FIG. 3 is an exploded perspective view showing the entire configuration of a variable apex angle prism device using the same.

FIG. 6 is a plan sectional view of the variable apex angle prism device.

FIG. 7 is a plan sectional view showing a case where a light beam is bent by the variable apex angle prism device.

FIG. 8 is a plan view showing a second embodiment of the movable magnet type swing actuator for the variable apex angle prism device according to the present invention, with a part thereof being in section;

FIG. 9 is an enlarged sectional view of a main part of the second embodiment.

FIG. 10 is an explanatory view showing a modified example of a movable magnet body usable in the present invention.

FIG. 11 is an exploded perspective view showing a variable apex angle prism device using a conventional moving coil type linear actuator.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Variable vertex angle prism 2 Bellows 3 Transparent glass plate 4A, 4B, 23 Holder 10 Moving coil type linear actuator 20, 20A, 20-1, 20-2 Moving magnet type rocking actuator for variable vertex angle prism device 21, 21A Movable magnet body 22 Oscillating shaft 30, 30A Fixed coil body 31 Resin bobbin 32, 32A, 32B Drive coil 33 Bearing 34 Speed detection coil 35, 36 External connection terminal 40 Magnetic yoke

Claims (4)

[Claims] 1. A movable magnet type oscillating actuator for a variable apex angle prism apparatus for moving at least one transparent member of a variable apex angle prism to change the direction of a light beam passing through the variable apex angle prism, A movable magnet body fixed to the transparent member so as to allow most of the light beam to pass therethrough, and a fixed coil which is fixedly arranged at least at a position through which most of the light beam passes and swings the movable magnet body by electromagnetic force A movable magnet type swing actuator for a variable apex angle prism device, comprising: 2. The movable magnet body has a hollow shape and is magnetized in a radial direction, and the magnetizing directions are opposite on one side and the other side with respect to a swing center axis. 2. The movable magnet type oscillating actuator for a variable apex angle prism device according to claim 1, wherein said fixed coil body has a drive coil wound around said movable magnet body inside or outside. 3. The movable magnet, wherein the movable magnet has a hollow shape and is magnetized in a longitudinal direction, and the fixed coil is wound around the inside or outside of the movable magnet. A first driving coil proximate the north pole of the body;
The movable magnet type oscillating actuator for a variable apex angle prism device according to claim 1, further comprising a second driving coil proximate to the pole. 4. A movable magnet type swing actuator for a variable apex angle prism device according to claim 1, wherein said fixed coil body has a speed detecting coil.