JP2003322889A - Camera shake compensation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a camera shake compensation device by which a compensation optical element is exactly supported by simple structure in an image stabilization device incorporated in a lens part of an imaging system. <P>SOLUTION: Arms (6a, 6b) are inserted into arm guides (2a, 2b) to be floatable on an XY plane. An arm (7) is slidably inserted in a hole (11) penetrating the side of a rotary bearing (9) and the rotary bearing (9) is pivotally supported to be freely to Y-&theta; by an axis (10) by a hole which is not illustrated, punched on a main body (1) in parallel with a light axis and a hole punched on a rotary bearing pressure foot (12) to be installed by poles (4a, 4b) provided on the main body. A mirror frame (5) freely moves in the Y direction without accompanying rotation and freely moves in the X direction while accompanying the rotation. A mirror chamber (5) moves its center to be freely to X-Y by permanent magnets (14a, 14b, 14c, 14d) consisting at least of two coils to one of a coil (13a) and a coil (13b) installed in coil holders (8a, 8b). <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an interchangeable lens type lens for a single-lens reflex camera, and more particularly to a device for alleviating the influence of camera shake during handheld photographing.

[0002]

2. Description of the Related Art A mechanism for moving a part of a correction lens constituting a photographing lens in a direction perpendicular to an optical axis predicts an image blur by detecting an acceleration of a camera shake which causes an image blur in a camera, for example. Then, by moving the lens in the direction perpendicular to the optical axis based on this prediction signal,
An anti-vibration device that suppresses image blur has been proposed and commercialized. Although various methods have been proposed for these anti-vibration devices, as described in the whole description, a mechanism that can move the correction lens in a direction perpendicular to the optical axis in any direction depending on the shooting posture of the photographer is used. Must-have.

For example, as disclosed in Japanese Unexamined Patent Publication No. 10-197911, a correction lens barrel is slidably supported by two points on a support shaft in order to correct image shake, and further, 9 of the support shaft is used.
The tip bent at 0 ° is slidably supported by the base plate at two points, and the guide direction of the support shaft used to suppress the rotation of the correction lens barrel is tilted at 45 ° between the support frame and the bearing portion. Although the generated prying is eliminated, the prying is unavoidable due to the existence of this supporting member.

Further, as disclosed in Japanese Patent Application Laid-Open No. 10-3102, two points are equidistant from the optical axis in a plane perpendicular to the optical axis with respect to the correction lens frame, and play is provided in the longitudinal direction of the link. A link having a structured width is arranged between the support frame and the support frame so that it is parallel to the optical axis, and the lens frame is supported XY freely. Although an object or the like that is connected to a support frame and supported XY freely by the above-mentioned arms has been proposed, in either case, the number of parts and the number of sliding points are increased.

Others, such as Japanese Patent Laid-Open No. 10-319464, use a frame that slides only in the X direction and a lens frame that slides only in the Y direction relative to the frame. There was a drawback that it was difficult to control backlash, etc., because it increased.

[0006]

In the prior art, a member for suppressing the rotation θ of the lens frame and a member for suppressing the Z displacement in the optical axis direction are independently configured. Since the amount of play is increasing and play is required to avoid sliding resistance, the influence on the optical performance and the smoothness of the correction operation becomes a problem. Further, since a large space is consumed in the radial direction or the optical axis direction for disposing the member that suppresses the rotation θ, it becomes difficult to dispose the drive device and the detection device.

[0007]

In order to solve the above problems, in the present invention, the structure for suppressing the rotational component θ by utilizing the rotational component θ of the lens frame for moving the correction optical system is abolished.

That is, the lens frame is suspended by three legs in the XY plane coordinates, one of the three legs is freely supported in the Y-θ direction, and the other two are supported in the XY direction. The optical axis was freely displaced in the XY directions while the lens was rotating, and the three legs were arranged in approximately three equal distributions.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of an image stabilization apparatus according to the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing an embodiment of an image stabilization apparatus according to the present invention, and FIG. 2 is an explanatory view showing an example of movement of a lens frame (5).

Two sets of arm guides (2) are provided in the main body (1) of the image stabilization apparatus shown in FIG. 1 and are provided with an elongated hole (3) along a plane perpendicular to the optical axis so as to be directed toward the center.
Two arms (6a, 6b), which are abutted on the a, 2b) from the lens frame (5) substantially equiangularly, are movably inserted in the XY plane. The third arm (7) of the lens frame (5) is slidably inserted into a hole (11) penetrating the side surface of the rotary bearing (9), and the rotary bearing (9) is parallel to the optical axis of the main body (1). A hole (not shown in the figure) and a column (4
(a) and (4b) are provided in the rotary bearing retainer (12), and the shaft (10) freely supports the Y-.theta. The center of the lens frame (5) freely moves in the Y direction without rotation, and can be freely positioned in the X direction while rotating. The mirror chamber (5) has coils (1) installed in two coil holders (8a, 8b) arranged at 90 °.
3a), the permanent magnets (14a, 14) are arranged at 90 ° and each coil (13b) has at least two permanent magnets (14a, 14).
b, 14c, 14d), the center can be freely moved in XY direction.

Two pairs of permanent magnets (14a, 14b, 14c, 14d) installed in the main body (1) are arranged substantially parallel with each pair having different poles upward. The centers of the respective coils (13a, 13b) installed in the coil holders (8a, 8b), which are part of the lens frame (5) when not eccentric, coincide with the respective center lines.
A magnetic field is generated when the coils (13a, 13b) are energized,
Two facing magnets (14a, 14b, 14c, 14
d) An attractive force is applied to one side and a repulsive force is applied to the other side, and as a result, the lens frame (5) moves in the direction normal to the optical axis. When electricity is applied in the opposite direction, the attractive force and the repulsive force are opposite, and the lens frame (5) moves in the opposite direction. A similar device is provided at a position rotated by about 90 °, and the center of the lens frame (5) is moved XY freely.

Next, the displacement of the lens frame of the image stabilizer according to the present invention will be described in more detail.

FIG. 2 is an explanatory view showing how the lens frame (5) moves.

FIG. 2A shows the lens frame (5) in the standard position.
And the positional relationship between each member. Center of mirror frame (5)
When O ′ is displaced by the maximum amount in the −Y direction, the state shown in FIG.

When both coils (13a, 13b) are energized so that the lens frame approaches the center of the optical axis, a resultant force is generated in the -Y direction in the figure and the lens frame (5) is displaced in the -Y direction.

FIG. 2D shows a state where the center O'of the lens frame (5) is displaced in the Y direction by the maximum amount, and when the respective coils are energized in the opposite direction to the -Y displacement, the resultant force is in the Y direction in the figure. It is generated and the lens frame (5) is displaced in the Y direction. The arm (7) can freely slide in the hole (11) penetrating the side surface of the rotary bearing (9).

In these two states, the lens frame (5) is not displaced by the rotation angle θ.

FIG. 2C shows a state in which the lens frame (5) is displaced by the maximum amount in the X direction. When one coil is energized toward the center of the optical axis and the other is energized away from the center of the optical axis. A resultant force is generated in the middle X (-X) direction, and the lens frame (5) is moved to the X (-
Displace in the X direction. Then, the rotary bearing (9) rotates and the arm (7) slides, so that the center of the lens frame (5) is reached.
O'can move exactly in the X direction. The same applies to the −X direction and other directions.

3 and 4 are plan views showing another form of the arm (7) and the rotary bearing (9).

In FIG. 3, the tip (7a) of the arm (7)
Is formed into a spherical shape or a cylindrical shape, and is configured to be able to freely support linear movement in the Y direction and rotational movement in the θ direction by the arm guide (20).

In FIG. 4, the tip of the arm (7) and the main body (1) are connected by a link portion (7b) provided with one degree of freedom in the rotational direction, and approximately Y is provided by a guide link (21).
The linear movement in the direction and the rotational movement in the θ direction can be freely supported.

As described above, the unit composed of the coils (13a, 13b) and the pair of permanent magnets (14a, 14b, 14c, 14d) is supplied with the amount of camera shake correction obtained from the sensor unit (not shown) by electric power and the lens frame. The coils (13a, 13b) fixed to (5) are operated in the direction perpendicular to the optical axis. The position of the center O'of the lens frame (5) is determined at a desired position by the resultant force of the two coils (13a, 13b).

[0024]

EFFECTS OF THE INVENTION Of the sliders arranged in a mirror frame in a substantially equal distribution, arms 6a, 6b and Y which freely move in the XY directions are provided.
The mirror chamber supported parallel to the lens frame base by three points of the arm 7 which is freely movable in the direction of rotation and in the direction of rotation, can move its center position XY freely from the center of the optical axis without tilting the optical axis. The camera-shake correction apparatus of the present invention can give an XY motion to the center of the optical axis of the correction optical system, and can correct the deviation angle due to the shake at the time of shooting, so that it has a simple structure. Therefore, highly accurate mirror room support can be obtained.

In the description, the coil and the magnet are used as the driving means for the lens frame, but it goes without saying that the same effect can be obtained by using other driving means. Of course, the lens frame support structure and the driving means may be arranged to face each other.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of an image stabilization apparatus according to the present invention.

FIG. 2 is a plan view showing how the lens frame (5) moves.

FIG. 3 is a plan view showing a second embodiment of the arm and the rotary bearing.

FIG. 4 is a plan view showing a third embodiment of the arm and the rotary bearing.

[Explanation of symbols]

1. Body 2. Arm guide 3. Slot 4. Prop 5. Mirror frame 6. arm 7. arm 8. Coil holder 9. Slewing bearing 10. Rotating bearing shaft 11. Side hole 12. Rotating bearing holder 13. coil 14. magnet

Claims (2)

[Claims] 1. A correction lens installed in a lens barrel for decentering an optical axis, a vibration detection unit for detecting vibration applied to the lens barrel, and the correction based on a signal obtained from the vibration detection unit. In a camera shake correction device equipped with a control means for driving a lens to prevent image shake, a lens frame holding the correction lens is suspended by three legs, and one of the three legs is Y- A camera shake correction device characterized in that the optical axis is freely supported in the XY direction while being freely supported in the θ direction and the other two are also supported in the XY directions. 2. The three legs for suspending the lens frame for holding the correction lens are arranged in approximately three equal distributions.
The image stabilization device described in.