JP2002290810A - Shake correcting device for camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for correcting a shake of a camera by a mirror which can improve the response of shake correction, make the constitution small-sized, and lower the cost by adopting a shake correction system using an optical system which is free from causing deterioration in picture quality. SOLUTION: This device can correct a shake of the camera by being equipped with a mirror which is arranged halfway in the optical path connecting the image formation surface and image pickup lens of an image pickup optical system of the camera, a mirror driving means which drives the mirror so that angle variation of the mirror cancels a shift of an image on the image formation surface caused corresponding to the shake quantity of the camera, and a control means which detects the shake quantity of the camera or the quantity of the image shift on the image formation surface and controls the driving means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a camera,
In particular, the present invention relates to a still camera and a video camera having a shake correction function using a mirror.

[0002]

2. Description of the Related Art Recently, camera apparatuses such as still cameras and video cameras have advanced in automation of shooting, and various functions such as an automatic exposure control function and an automatic focus control function have been put to practical use. ing. As one of these automation functions, for example, a correction means for reducing harmful screen shake (so-called camera shake) caused by camera shake has been invented and put into practical use.

On the other hand, in a camera device such as a digital camera or a video camera which captures an image with a solid-state imaging device and records it in a semiconductor memory or the like, it is common to use a zoom lens as an imaging lens, and a zoom ratio of the zoom lens. Is increasing year by year.

Further, with the development of high-density mounting technology, the miniaturization of camera devices and the miniaturization of the imaging screen size of a solid-state imaging device for photoelectric conversion, and the like have resulted in the emergence of small models capable of performing one-handed photographing. ing. For this reason, screen shake correction is adopted as an essential function in most cameras.

However, as a correction means for reducing harmful screen shake caused by camera shake, a solid-state image pickup device drive control method most often used is to provide a window at a position narrower than an effective pixel area of the solid-state image pickup device. , According to the control signal obtained from the camera shake detector,
Since the readout position of the solid-state imaging device is changed and this window is moved to correct the fluctuation, the image quality is inevitably reduced due to the inability to use all the effective pixel areas.

[0006] The shake correction method using an optical system is a correction method that does not cause deterioration in image quality. For example, a vari-angle prism (variable apex prism) method, which can be moved in a direction perpendicular to the optical axis of the imaging optical system. Excellent shake correction methods such as a correction method using various lens groups have been put into practical use.However, in order to control the relatively heavy parts that are being used to change the angle or to move them, There is a limit to improving the response and reducing the size of the shake correction.

[0007]

Means for Solving the Problems In view of the above situation, the present invention employs a shake correction method using an optical system that does not cause deterioration in image quality, thereby improving the response of shake correction and reducing the size. This problem has been solved by a shake correction device using a mirror that can reduce the cost.

(1) An imaging surface of an imaging optical system of a camera, an imaging lens, a mirror disposed in the middle of an optical path connecting the imaging lens, and an image on the imaging surface generated by the mirror according to the amount of camera shake Mirror driving means for driving the mirror so as to cancel the image shift by changing the angle of the mirror, and control for detecting the shake amount of the camera or the image shift amount on the image forming surface and controlling the drive means. Means for correcting camera shake.

(2) The camera according to the above (1), wherein the mirror is disposed at an angle of reflection at an incident angle or a reflection angle of 35 to 55 degrees with respect to a normal line of the mirror. Shake correction device. (3) The camera shake correction apparatus according to the above (1) or (2), wherein the mirror is rotated about its reflection surface as a rotation axis. (4) The camera shake correction apparatus according to any one of (1) to (3), wherein the mirror is a half mirror or a beam splitter.

(5) The mirror according to any one of (1) to (3), wherein the mirror is an infrared reflecting mirror.
Item 2. The camera shake correction device according to Item 1. (6) The mirror according to (1) to (5), wherein the mirror is a mirror-finished metal material or a light metal material such as an aluminum alloy, or a glass material or a resin material on which a metal thin film is adhered.
The camera shake correction device according to any one of claims 1 to 7.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS According to the present invention, a metal material, a metal material such as an aluminum alloy, or a metal thin film, which is disposed in the middle of an imaging surface of an imaging optical system of a camera, an imaging lens, and an optical path connecting them, and is mirror-finished. With a reflecting mirror, a half mirror or a beam splitter, or an infrared reflecting mirror using glass material or resin material on which the mirror is attached. Mirror drive means for driving so as to cancel the image shift by changing the angle of the mirror, and control means for controlling the drive means by detecting the shake amount of the camera or the image shift amount on the image plane. , And constitutes a shake correction device.

[0012]

An embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a configuration block diagram of a video camera equipped with a shake correction mechanism according to an embodiment of the present invention. FIG. 2 is a perspective view of the driving means of the embodiment. In the figure, 1 is a zoom lens, 1a is a relay lens system, 2 is a mirror, 3 is a prism, 4 is a solid-state imaging device (CCD), 5 is a camera, 6 is a displacement sensor unit, 7 is control means, and 8 is drive means. , 8a is an X-axis drive unit, 8b is a Y-axis drive unit, 9a and 9b are position detection units, 10 is a frame, 11 is a release button,
Reference numeral 12 denotes a swing operation switch.

As an embodiment of the present invention, an apparatus for compensating the camera 5 for shaking by the mirror 2 will be described. In FIG. 1, a relay lens system 1 forming a part of a zoom lens 1 is shown.
A reflection mirror 2 is disposed in a at an angle at which an incident angle or a reflection angle with respect to the normal line of the mirror 2 is reflected, for example, at 45 degrees, and a subject image taken by the zoom lens 1 is solid-state imaged through a prism 3. An image is formed on a pixel array surface of the device 4 (hereinafter, referred to as a CCD).

Displacement from a displacement sensor (a liquid inertia applied displacement sensor, etc.) unit 6 for detecting the amount of swing of each of the right and left (X-axis) and up-and-down (Y-axis) cameras 5 provided inside the camera 5 main body and provided with an amplifier. The signal is applied to the control means 7 provided with a CPU by closing the swing operation switch 12, and outputs a control signal in accordance with the displacement signal, and the driving means 8
To control the angle of the mirror 2.

In FIG. 2, a driving means 8 is a driving device applying the principle of a gyro compass, and includes a frame 10 and
A mirror mounted on the inside of the frame 10, and a camera 5 driving the frame 10 in the X-axis direction together with the mirror 2.
An X-axis drive unit 8a fixed to the body, an Y-axis drive unit 8b for driving the mirror 2 in the Y-axis direction fixed to the frame 10, and an outer case fixed to the camera 5 main body and the shaft An X-axis position detection unit 9a is connected to the frame 10, and a Y-axis position detection unit 9b is fixed to the frame 10 and connected to the axis of the mirror 2. The axes of the X and Y position detection units have the reflection surface of the mirror 2 as the center of the rotation axis.

The driving method of the X-axis driving unit 8a is as follows. A plate-shaped (or rod-shaped) magnetic material (not shown) fixed to the frame 10 is supplied to a coil (not shown) provided in the X-axis driving unit 8a by a current. Driven by As described above, the displacement signal from the displacement sensor unit 6 is applied to the control means 7 having a CPU, and the control signal output from the control means in accordance with the displacement signal is input to the X-axis drive unit 8a, where The magnetic body fixed to the frame is driven by a drive current flowing through the disposed coil. As a result, since the mirror 2 is mounted on the frame 10, the mirror 2 can be corrected so as to cancel the shake in the X-axis direction according to the shake amount of the camera.

The driving method of the Y-axis driving unit 8b is as follows. A plate (or rod-shaped) magnetic material (not shown) fixed to the mirror 2 is supplied to a coil (not shown) provided in the Y-axis driving unit 8b by applying a current. Driven by Similarly to the above, a control signal is output from the control means 7 in accordance with the displacement signal from the displacement sensor unit 6 to drive the Y-axis drive unit 8b fixed to the frame 10. As a result, correction is made so as to cancel the fluctuation in the Y-axis direction according to the fluctuation amount of the camera. If the X and Y axis drive units 8a and 8b are driven simultaneously, it is needless to say that the shake can be corrected so as to cancel the shake of the camera 5 in any direction.

Here, the displacement angle of the mirror 2 is determined by a position detecting unit 9a using a rotary encoder or the like.
The mirror 2 is detected at 9b and fed back to the control means 7 to stop the mirror 2 at an appropriate position. After confirming that the shake correction is operating as described above, if the release button 11 (or the recording start / stop button or the like) is pressed, an image with the shake corrected can be recorded.

In this embodiment, the mirror driving means 8 is described in the moving magnet system, but may be in the moving coil system. Alternatively, a mirror control method using a micro motor may be used.

It is preferable that the mirror 2 is made of a lightweight metal material such as a metal material or an aluminum alloy, or a glass material or a resin material, and the mirror surface of which is mirror-finished or a metal thin film is applied. Further, a half mirror or a beam splitter may be used to dispose an autofocus function element behind the mirror 2 for mounting the autofocus function. Further, if the mirror 2 is an infrared reflecting mirror, an infrared camera with shake correction can be obtained.
Furthermore, in the present embodiment, the description has been given of the 3CCD system.
A single-plate CCD system or a still camera system using a silver halide film may be used.

The sway amount detecting means is provided by the CC as in this embodiment.
When D is used, a motion vector is detected from the video signal amplified by photoelectric conversion using digital image processing technology. A frequency component necessary for motion vector detection is extracted from a video signal by a horizontal and vertical bandpass filter, and the motion vector is detected by a representative point matching method. Thus, the number of representative points can be reduced without lowering the detection accuracy. It is also preferable to use a well-known video signal detection method such as fuzzy inference to improve the effect of discrimination between the shake and the movement of the subject or the pan of the camera.

[0022]

According to the present invention, the following effects are exhibited. (1) A mirror is provided so as to reflect at an incident angle or a reflection angle of 35 to 55 degrees, and the mirror is driven in the X-axis and Y-axis directions about the reflection surface of the mirror as a rotation axis, thereby causing camera shake. It operates so as to cancel out the image shift on the image plane caused by the amount, so that the camera can be downsized and the camera shake can be corrected by an optical system that does not deteriorate the image quality.

(2) The application can be expanded by properly using a mirror as a reflection mirror, a half mirror, a beam splitter having good light use efficiency, or an infrared reflection mirror.

(3) By using a light metal material such as a metal material or an aluminum alloy, or a glass material or a resin material as a material of the mirror, the drive is easy because of its light weight, and the mirror is excellent in response characteristics. A shake correction device can be realized.

[Brief description of the drawings]

FIG. 1 is a configuration block diagram of a video camera equipped with a shake correction mechanism according to an embodiment of the present invention.

FIG. 2 is a perspective view of a driving unit of the embodiment.

[Explanation of symbols]

1: Zoom lens 1a: Relay lens system 2: Mirror 3: Prism 4: Solid-state imaging device (CCD) 5: Camera 6: Displacement sensor unit 7: Control means 8a: X-axis drive unit 8b: Y-axis drive unit 9: Position Detection unit 10: Frame 11: Release button 12: Swing operation switch

Claims (6)

[Claims] 1. An imaging surface of an imaging optical system of a camera, an imaging lens, a mirror disposed in the middle of an optical path connecting the imaging lens, and a mirror of an image on the imaging surface generated in accordance with a shake amount of the camera. Mirror driving means for driving the mirror so as to cancel the image shift by changing the angle of the mirror, and control means for detecting the amount of shaking of the camera or the amount of image shift on the image forming surface and controlling the driving means And a camera shake correction device. 2. The camera shake according to claim 1, wherein the mirror is arranged at an angle of reflection at an incident angle or a reflection angle of 35 to 55 degrees with respect to a normal line of the mirror. Correction device. 3. The camera shake correction device according to claim 1, wherein the mirror is rotated about a reflection surface of the mirror as a rotation axis. 4. The camera shake correction apparatus according to claim 1, wherein the mirror is a half mirror or a beam splitter. 5. The camera shake correction apparatus according to claim 1, wherein the mirror is an infrared reflection mirror. 6. The mirror according to claim 1, wherein the mirror is a mirror-finished metal material, a light metal material such as an aluminum alloy, or a glass material or a resin material on which a metal thin film is adhered.
6. The camera shake correction device according to any one of items 5.