JPH02304535A - Image blurring correction device and correcting lens driving device for camera - Google Patents

Abstract

PURPOSE:To correct image blurring by normally making a correcting lens supported by a turning member coincident with the photographic optical axis with a V groove and a ball body and driving the correcting lens from the neutral position to the right or the left at the time of image blurring. CONSTITUTION:A correcting lens 15 is supported by a turning member 16 which has the center 17 of turning on the outside of the correcting lens 15, and the turning member 16 is normally held in such neutral position that the optical axis of the correcting lens 15 coincides with the photographic optical axis. In this case, the V groove 22 is formed on the turning member 16 or a fixed frame 14 in the radial direction of the correcting lens 15, and the ball body 21 is pressed to the bottom part of the V groove by a spring 20 to support the turning member 16 in the neutral position. Electromagnets 24 and 25 which attract and move a piece 23 to be driven of a magnetic body protruded from the turning member 16 in the radial direction are provided on the right and the left of this piece 23, and the turning member 16 is turned to the right or the left from the neutral position in accordance with the direction of camera blurring. Thus, the image blurring is prevented more surely.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to an image blur correction device for a camera and a correction lens driving device.

``Prior art and its problems'' When using a hand-held camera (for best shadow shooting), camera shake may occur if the camera is not held up perfectly, when shooting a dark subject with a slow shutter speed, or when the photographer is moving while shooting. Photos with camera shake tend to have blurred images and are extremely unsightly.From a hardware perspective, this camera shake can be fixed by brightening the lens (or increasing the film sensitivity and increasing the shutter speed). From a software perspective, this problem can be prevented to some extent by the skill of the photographer, but there are limits to both.

In order to prevent such image blurring, when camera shake that causes blurring of the photographic optical axis occurs, the magnitude of the shake is detected as an angular velocity or angular acceleration applied to the camera, and this angular velocity or angular acceleration is detected. In response to this, an image blur correction device has been proposed based on the idea of preventing image blur by displacing a correction lens in the direction opposite to the direction in which camera shake occurs and restoring the camera shake.

However, in order to put this image blur correction device into practical use, it is essential to develop a compact and high-performance correction lens drive device that can be mounted on a camera.

``Object of the Invention'' Accordingly, an object of the present invention is to obtain a compact and high-performance correction lens driving device. Another object of the present invention is to obtain an image blur correction device that is equipped with this correction lens drive device and can quickly and efficiently operate the correction lens in response to detected camera shake to more reliably prevent image blur. do.

"Summary of the Invention" The present invention provides an image stabilization device for a camera that detects shake applied to the camera and moves a compensation lens of a photographing optical system in a direction to reduce image blur. The correction lens is supported on a rotating member having a rotation member, and this rotating member is normally held in a neutral position where the optical axis of the correction lens coincides with the photographing optical axis, and the rotating member is held in a neutral position where the optical axis of the correction lens coincides with the photographing optical axis. The invention is characterized in that it is provided with a driving means for distributing rotation from the neutral position to the left and right depending on the situation.

For example, the neutral position holding means may include a V-groove formed in one of the rotating member and the fixed frame toward the radial direction of the correction lens, and a ball body that fits into the V-groove and a ball body formed on the other side. It can be configured by supporting a spring means that biases the bottom of the V-groove.

The driving means can be constructed, for example, by providing a driven piece made of a magnetic material that projects in the radial direction from the rotating member, and arranging electromagnets on the left and right sides of the driven piece to attract and move the driven piece.

The present invention also proposes an image blur correction device for dealing with camera shake in two orthogonal directions. This image stabilization device is provided with a pair of the above-mentioned rotating members, and the rotational centers of the two pairs of rotating members are arranged at positions substantially perpendicular to the imaging optical axis. , the correction lens is supported in such a manner that rotation of the pair of rotation members is transmitted to the correction lens independently of each other. By rotating this pair of rotating members in response to camera shake in mutually orthogonal directions, camera shake in two orthogonal directions, that is, camera shake in all directions within one plane, can be addressed and image blur can be prevented. can do.

"Embodiments of the Invention" The present invention will be described below with reference to illustrated embodiments. Figure 1A,
Figure 18 shows a first embodiment of the invention.

A correction lens 12 is located after the main photographic lens 11 of the camera. This correction lens 12 is the main photographing lens 11.
Together, they constitute a photographing optical system. The lens frame 13 of the main photographing lens 11 has an optical axis O within a fixed frame 14 for focus adjustment.
It is possible to move in the direction. The correction lens frame 15 to which the correction lens 12 is fixed is fitted into a support hole (support opening) 19 provided in a rotating member 16, and this rotation member 16 has a rotation center located outside the correction lens frame 15. It is rotatably supported on a shaft 17.

The rotating member 16 has an arm 18 extending in the opposite direction of the rotation center axis 17 with respect to the optical axis O, and a compression spring 20 is attached to the arm 18.
and a ball body 21 urged in the direction of the optical axis 0 by this compression spring 20 are supported. On the other hand, the fixed frame 14 is formed with a V-groove 22 oriented in the optical axis O direction (radial direction of the correction lens 12) into which the ball body 21 is fitted.

That is, V122 is provided symmetrically with respect to the radial direction of the correction lens.

A driven piece 23 made of a magnetic material is protruded from the tip of the rotation center shaft 17 of the rotation member 16 .

Electromagnets 24 and 25 are fixed to the fixed frame 14 at a constant interval on the left and right sides of the rotation center axis 17, respectively.

In the tree image blur correction device having the above structure, when no driving voltage is applied to the electromagnets 24 and 25, the force of the compression spring 20 causes
The ball body 21 is located at the center of the V-groove 22. In this neutral position, the optical axis of the correction lens 12 coincides with optical axis 0.

On the other hand, when one of the electromagnets 24 and 25 is energized, the driven piece 23 is attracted to the energized electromagnet, and the rotating member 16 (correction lens 12) rotates around the rotation center axis 17. move. The rotation angle of the rotation member 16 is determined by the electromagnet 24
Or it can be controlled by the amount of electricity applied to 25, and the rotation direction is
Control can be performed by energizing either the electromagnets 24 or 25.

Strictly speaking, the correction lens 12 moves not in a straight line but in a circular arc, but the distance is extremely short (for example, ±0.5m+n).
degree) is sufficient, so it can be approximately regarded as linear motion.

Therefore, if the subject image on the film surface 30 attempts to move due to horizontal movement of the camera, an appropriate drive voltage corresponding to the amount and speed of the camera movement can be applied to the electromagnet 24 or 25. , the subject image can be kept stationary on the film surface 30.Also, if the electromagnet 24 or 25 is de-energized, the compression spring 20
, by the action of the ball body 21 and the V-groove 22, the correction lens 12 (rotating member 16) returns to the neutral position.

In FIGS. 1A and IB, for convenience of explanation, the rotation center axis 17 of the rotation member 16 is positioned below the optical axis 0, and the correction lens 12 is moved in the left-right direction, but in an actual camera, Image blur that occurs is often caused by vertical angular blur that occurs when the shutter button is pressed down.
Therefore, when applying the present invention to an actual camera, it is practical to position the rotation center axis 17 on either the left or right side of the optical axis 0 to correct vertical image blur.

FIG. 2 shows a control system of a camera having the above image blur correction device. The camera 31 is equipped with the device shown in FIG. 1, but only the main photographic lens 11, correction lens 12, rotating member 16, and electromagnet 24 (25) are shown in the figure. The camera 31 is further equipped with an angular velocity sensor or an angular acceleration sensor 32. This angular velocity sensor or angular acceleration sensor 32 may be any sensor as long as it can detect the magnitude of camera shake, but for example, the angular velocity sensor rEYK-GO2CJ manufactured by Matsushita Electronic Components Co., Ltd.
(product number) can be used. This angular velocity sensor utilizes the Coriolis force generated by a vibrating tuning fork, and consists of a gyro signal detection unit made of two bimorphs shaped like a T-shape, a snow-proof gyro signal detection unit, a tuning fork drive circuit, and a signal processing circuit.

Furthermore, the angular acceleration sensor proposed by the present applicant in Japanese Patent Application No. 1-84318 can also be used.

The camera shake signal detected by the angular acceleration sensor 32 is manually input to the signal processing circuit 34.
4 generates an output proportional to the amount of angular deviation of the optical axis O, and inputs this to a judgment circuit (comparator) 35. Judgment circuit 3
5 is the input from the signal processing circuit 34 and the reference voltage V r
e and f to determine whether or not to energize the electromagnet 24 or 25 and the energization time. The driver circuit 36 applies a drive voltage of an appropriate magnitude to the electromagnet 24 or 25 according to the output of the determination circuit 35.

In the control device configured as described above, when optical axis blur occurs due to the pressing down operation of the shutter button, the blur is detected by the angular acceleration sensor 32. When the amount of optical axis blur exceeds a certain value, the control system shown in the figure applies an AC voltage to the electromagnet 24 or 25 to move the correction lens 12 so as to eliminate image blur caused by the optical axis blur. Therefore, even if camera shake occurs when the shutter button is pressed down, a photograph with no or suppressed image shake can be obtained.

In the embodiments of FIGS. 1 and 2, the direction of movement of the correction lens 12 is one-dimensional. For this reason, although images can be obtained that suppress image blur due to vertical blurring of the optical axis that occurs when the shutter button is pressed down, for example, it does not prevent camera shake that includes components in all directions, up, down, left, and right, which occurs when the shutter is pressed for a long time. Can not.

FIGS. 3A and 3B show an embodiment in which the correction lens 12 is movable in all directions within a plane perpendicular to the optical axis 0 so as to cope with camera shake in the vertical and horizontal directions. This device basically uses two sets of image blur correction devices shown in FIGS. 1A and 1B, and the rotation center positions of a pair of rotating members 16V and 16H are positioned at approximately right angles with the optical axis O as the center. and the pair of rotating members 16V and 16H.
The rotation of the pair of rotation members is independent of each other when the correction lens 1
The feature is that the correction lens 12 is supported so that the information is transmitted to the lens 2.

In FIGS. 3A and 3B, regarding the two sets of image stabilization devices, the elements explained in FIGS. It has an H suffix. The configuration of each image blur correction device is the same as that shown in FIGS. 1A and 18, so a description thereof will be omitted. The rotation center axis 17■ of the rotation member 16V and the rotation center axis 17H of the rotation member 16H are aligned with the optical axis O.
It is clear from FIG. 3B that a right angle is formed around the center. For convenience of illustration, FIG. 3A depicts the v--■ cross section and the H--H cross section of FIG. 3B superimposed.

The support opening 19V of the rotating member 16V has an oval shape with a pair of parallel sides 19VH in the horizontal direction, and makes line contact with the circular correction lens frame 15 of the correction lens 12 at the center of the parallel sides 19VH. On the other hand, the support opening 19H of the rotating member 16H has an oval shape with a pair of parallel sides 19HV in the vertical direction, and the circular correction lens frame 15 of the correction lens 12 similarly has the parallel sides 19HV. Line contact at the center. A flange 38 is formed on the correction lens frame 15 to prevent it from falling off from the lenses 19V and 19-4. According to the above support mode, when the rotating member 16V swings about the rotation center axis 17V, the correction lens 12 moves in the vertical direction, and the rotating member 16H prevents this movement of the correction lens 12. There is no. Similarly, when the rotating member 16I swings about the central axis of rotation 17H, the correction lens 12 moves in the left-right direction, and the rotating member 16V does not interfere with this movement of the correction lens 12. Therefore, the correction lens I2 can be freely moved vertically and horizontally. Of course, other support modes may be used to support the pair of rotating members 16 that are orthogonal to each other so that the rotations are transmitted to the correction lens 12 independently of each other.

Electromagnets 24V, 25V and electromagnets 24H125H are
An angular velocity or angular acceleration sensor detects vertical camera shake applied to the camera, and an angular velocity or angular acceleration sensor detects horizontal camera shake, respectively.
It is controlled in the same manner as described with respect to FIG. Therefore, it is possible to reduce or prevent image blur by moving the correction lens 12 so as to correct blur in all directions applied to the camera.

As seen in the embodiments of FIGS. 1 and 3, the image stabilization device of the present invention can have its components made of flat, thin members, and can therefore be used in a limited space within the camera. It can be easily installed on the

Note that the correction lens driving device of the present invention can be used for purposes other than image blur correction devices.

``Effects of the Invention'' As described above, the present invention supports a correction lens on a rotating member having a rotation center outside the correction lens, and the correction lens is always aligned with the photographing optical axis by a neutral position holding means. When image blur is applied to the camera, the correction lens is moved from the neutral position to the left or right to correct the image blur, so it is a compact image stabilization system that can be mounted on a small camera. A device is obtained. In particular, if the neutral position holding device is formed by the groove and the ball body, and the drive device is formed by a driven piece made of a magnetic material and an electromagnet, a simple and inexpensive image blur correction device can be obtained.

Further, the correction lens driving device of the present invention can be used for applications other than image blur correction devices, and the correction lens can be easily moved toward and away from the optical axis.

[Brief explanation of drawings]

1A and 18 show a first embodiment of the image blur correction device for a camera according to the present invention, and FIG.
A sectional view taken along line A, and FIG. 1B is a front view of the main elements. FIG. 2 is a block diagram showing a control system of the image blur correction device shown in FIG. 1. FIGS. 3A and 3B show another embodiment of the image blur correction device for a camera according to the present invention. ■ in Figure 3B
- Cross-sectional view combining the cross sections along line ■ and line H-H, 3rd A
The figure is a front view of the main elements. 11... Main photography lens, 12... Correction lens, 13
... Lens frame, 14... Fixed frame, 15... Correction lens frame, 16... Rotating member, 17... Rotating center axis,
18...Arm, 19...Support opening, 19VH% 19
HV...parallel side, 20...compression spring, 21...ball body, 22...V groove, 23...driven piece, 24.
25... Electromagnet, 30... Film surface, 31...
Camera, 32... Angular velocity or angular acceleration sensor, 34
...Signal processing circuit, 35...Judgment circuit, 36...
driver circuit. Patent applicant Asahi Optical Co., Ltd. Agent Kunio Miura Figure 2A Figure 18

Claims (5)

[Claims] (1) In a camera image stabilization device that detects shake applied to the camera and moves a correction lens of a photographing optical system in a direction to reduce image blur, the rotation center is outside the correction lens, and the a rotating member that supports the correction lens; a holding means that normally holds the rotating member in a neutral position where the optical axis of the correction lens coincides with the photographing optical axis; An image stabilization device for a camera, comprising: a drive means for distributing and rotating left and right from a neutral position. (2) In a camera image stabilization device that detects camera shake in directions perpendicular to each other and moves a correction lens of the photographic optical system in a direction to reduce image blur, the rotation center is located outside of the correction lens. a pair of rotating members having a rotational axis, the rotational centers of which are substantially perpendicular to the photographing optical axis; a support mechanism that supports the pair of rotating members so that the images are transmitted to the correction lens almost independently of each other; and a holding means that normally holds the pair of rotating members in a neutral position where the optical axis of the correction lens coincides with the photographing optical axis. an image stabilization device for a camera, comprising: a driving means for distributing and rotating the pair of rotating members left and right from a neutral position according to shake applied to the camera; (3) In claim 1 or 2, the neutral position holding means includes a V groove formed in either the rotary member or the fixed frame and facing in the radial direction of the correction lens; An image stabilization device for a camera comprising a ball body that fits into a groove and a spring means that biases the ball body against the bottom of the V-groove. (4) In claim 1 or 2, the driving means includes a driven piece made of a magnetic material that projects in the radial direction from the rotating member, and electromagnets arranged on the left and right sides of the driven piece. Camera image blur drive device. (5) a rotating member that has a rotation center outside the correction lens of the photographing optical system and supports the correction lens; the optical axis of the correction lens normally coincides with the photographing optical axis; A correction lens driving device comprising: a holding means for holding the rotating member at a neutral position; and a driving means for distributing and rotating the rotary member left and right from the neutral position.