JPH0337633A - Vibration proof camera - Google Patents

Abstract

PURPOSE:To achieve a vibration proof effect regardless of the change of external environment by providing a vibration proof sensitivity changing means for changing the suppression ratio of vibration-proofing to inputted vibration. CONSTITUTION:Amplification factor variable amplifiers 11P and 11Y are connected between integration circuits 55P and 55Y and differential amplifiers 68P and 68Y and amplification factor variable commanding signals 12P and 12Y are inputted in the amplifiers 11P and 11Y. In the case that the sensitivities of a position detecting sensor 58P and a vertical blurring detector 53P are out of order when a photographer looks in a finder, he can view that the suppression ratio of vibration-proofing to blurring is low and adjust it to be proper with a dial. Then, the lowering of the vibration proof sensitivity caused by the change of the sensitivities of the blurring detector 53 and the position detecting sensor 58 for detecting the position of a correction optical system 56 by a temperature is freely compensated by changing the amplification factor of the amplification factor variable amplifier 11 from the outside. Thus, the vibration proof effect is achieved regardless of the change of the external environment.

Description

[Detailed Description of the Invention] (Field of Application of the Invention) The present invention relates to an improvement in an anti-shake camera that detects vibrations at a relatively low frequency of about IHz to 12Hz and prevents image blur based on this. .

(Background of the invention) In recent cameras, all important tasks for photography, such as exposure determination and focus adjustment, are automated, so even those who are inexperienced in camera operation are less likely to make a mistake in taking a picture. However, it was not possible to automatically prevent shooting failures due to camera shake. Therefore, research has recently been carried out on cameras that can prevent failures in photography due to camera shake, and in particular, research and development is progressing on cameras that can prevent failures in photography due to camera shake. .

The above-mentioned camera shake is usually a vibration with a frequency of IHz to 12Hz, but in order to be able to take pictures without image blur even if such camera shake occurs at the time of camera shutter release, it is necessary to It is necessary to detect the vibration of the camera due to camera shake and to displace the correction lens according to the detected value. In order to achieve this, it is necessary to accurately detect camera vibration.

In principle, the camera pre-detection described above is based on angular acceleration,
This can be done by mounting on the camera a vibration sensor that detects angular velocity, etc., and a camera pre-detection system that electrically or mechanically integrates the sensor signal and outputs the angular displacement.

Here, an outline of the image pre-suppression system using an angular velocity meter will be explained using FIG. 2.

The example in FIG. 2 shows vertical camera shake 51 P in the direction of the arrow 51 shown in the figure.
(P: Pitch) and camera horizontal shake 51Y (Y
: yaw) is a diagram of a system for suppressing. In the figure, 52 is a lens barrel, and 53P and 53Y are vertical shake and horizontal shake detectors, which are angular velocity meters that detect the angular velocity of the camera's vertical motion and the angular velocity of the camera's horizontal motion, respectively. Indicated by 54Y, 55P and 55Y are pre-detectors 53P.

This is a known analog integration circuit that integrates the signal from 53Y and converts it into a hand angle displacement, and the output is sent to the correction optical system 5.
6 (57P, 57Y are the drive parts, 58P, 58
Y is used as a signal to drive the position detection sensor (position detection sensor) to ensure stability on the image plane 59.

FIG. 3 shows the correction optical means (correction optical system 56, drive units 57P, 57Y, position detection sensors 58P, 58Y) shown in FIG.
is an enlarged view and a block diagram showing the circuit configuration of the main parts, and the correction optical system 56 has two axes 61P,
It is rotatably supported in the 61Y direction. Therefore, the correction optical system 56 is moved by the arrow 51P,
It is movable in the 51Y direction.

The drive units 57P, 57Y are known voice coils, and the yokes 63P, 63Y (6
4P and 64Y are permanent magnets) and the driving force is generated by Fleming's law using the current flowing through the coil.

The gimbal 62 is provided with position detection sensors 58P and 58Y, which are magnetoresistive sensors.Due to their relationship with magnetic markers 65P and 65Y (65Y is provided on the inner cylinder of the lens, not shown), The declination angles 61P and 61Y of the correction optical system 56 with respect to the camera lens are detected.

As shown in the figure, position detection amplifiers 66P, 66Y, compensation circuits 67P, 67Y for stabilizing characteristics, differential amplifier 68P,
68Y, drive circuit 69P69Y are connected, and these perform well-known position control, and the high frequency band f, (・5
It responds faithfully to input up to 0Hz). Then, an integrating circuit 55P passes through vertical shake and horizontal pre-detectors 53P and 53Y.
.

When there is no input from 55Y, the correction optical system 56 is controlled so that it is always parallel to the optical axis, and when there is input (camera shake) from the integrating circuits 55P and 55Y, the correction optical system 56 changes the light accordingly. It forms an angle of declination with the axis.

In addition, since the refractive power of the lens is adjusted so that the sensitivity of the image movement to the optical axis deviation angle of the correction optical system 56 is "1",
For example, when the hand angle increases by +0.5 degrees, the correction optical system 5
By tilting 6 by -0.5 degrees, image blur can be canceled out.

The correction optical system 56 is balanced by a lens 610 and yokes 63P and 63Y with a gimbal 62 in between.
As long as an external force around 61P and 61Y does not act, the force of voice coils 57P and 57Y is not required, and the camera always remains parallel to the photographing optical axis.

A vibrating gyro is a suitable angular velocity meter for achieving the above-mentioned purpose, and the vibratory gyro is a known gyro which calculates angular velocity by detecting Coriolis, which is proportional to the product of the vibration velocity and the input angular velocity. Although a detailed explanation will be omitted, it has the characteristics of "small size, high detection accuracy, and high durability."

However, a drawback of the vibrating gyroscope is that the angular velocity detection sensitivity changes greatly due to disturbances such as ambient temperature. Furthermore, the position detection sensors 58P and 58Y of the correction optical system 56 also have temperature characteristics in their sensitivity, so even if it is possible to create an anti-shake camera that sufficiently cancels out camera shake at room temperature, camera shake at -10 degrees Celsius is There is a problem in that the suppression of the camera shake is not sufficient, and at +60° C., the camera shake is even exacerbated.

(Objective of the Invention) An object of the present invention is to solve the above-mentioned problems and provide an anti-shake camera that can sufficiently exhibit an anti-shake effect regardless of changes in the external environment.

(Features of the Invention) In order to achieve the above object, the present invention provides vibration isolation sensitivity changing means for changing the suppression ratio of vibration isolation with respect to input vibration, and thereby prevents changes in the characteristics of the vibration detection means due to changes in the external environment. The present invention is characterized in that the resulting deterioration in vibration isolation sensitivity is compensated for from the outside by vibration isolation sensitivity changing means.

(Embodiment of the Invention) FIG. 1 shows an embodiment of the main part of the present invention, and the difference from the conventional example shown in FIG. Amplifier 11P, II
This is the point where Y is connected.

Variable amplification command signals 12P and 12Y are input to the variable amplification factor amplifiers 11P and IIY. These amplification factor variable command signals 12P, 12Y are a known variable resistor (not shown) such as a dial type attached to the camera body, and are transmitted to a vertical pre-detector 53P via an integrating circuit 55P.
The sensitivity of the manual output can be changed by the photographer operating the dial.

Here, when the photographer looks through the finder, if the sensitivity of the position detection sensor 58P and vertical pre-detector 53P is incorrect,
You can visually see that the image stabilization suppression ratio for camera shake is low (the subject image looks blurry), and you can adjust the dial to make it appropriate.

According to the present embodiment, the variable amplification factor amplifier 11 amplifies the reduction in vibration damping sensitivity caused by temperature-related changes in the sensitivity of the position detection sensor 58 for detecting the positions of the pre-detector 53 and the correction optical system 56. Since the configuration allows for flexible compensation by changing the ratio from the outside (while looking through the viewfinder), it is possible to prevent image blurring from occurring due to changes in the sensitivity of the pre-detector 53 and position detection sensor 58. It is possible to prevent this.

(Correspondence between the invention and the embodiments) In this embodiment, the position detection sensor 58 serves as the position detection means of the present invention, the pre-detector 53 serves as the vibration detection means, the integrating circuit 55, the driving section 57, the position detection amplifier 66, the compensation circuit 6
7. The differential amplifier 68 and the drive circuit 69 correspond to vibration isolation means, and the variable gain amplifier 11 and the variable resistor (not shown) correspond to vibration isolation sensitivity changing means.

(Effects of the Invention) As described above, according to the present invention, the vibration isolation sensitivity changing means for changing the vibration isolation suppression ratio with respect to input vibration is provided, and thereby the characteristic change of the vibration detection means due to changes in the external environment is prevented. Since the resulting deterioration in vibration isolation sensitivity is compensated for from the outside by the vibration isolation sensitivity changing means, the vibration isolation effect can be fully exhibited regardless of changes in the external environment.

[Brief explanation of drawings]

Fig. 1 is a diagram showing a correction optical system and an electric block showing an embodiment of the present invention, Fig. 2 is a diagram showing a schematic configuration of this type of anti-shake camera, and Fig. 3 is a diagram showing the correction of a conventional anti-shake camera. It is a figure showing an optical system and a concrete electric block. 11... Variable amplification factor amplifier, 53...
Pre-detector, 55...Integrator circuit, 56...
...Correction optical system, 57... Drive section, 58...
... Position detection sensor, 66 ... Position detection amplifier, 67 ... Compensation circuit, 68 ... Differential amplifier, 69 ... Drive circuit.

Claims (1)

[Claims] (1) A correction optical system that is disposed inside the lens barrel and is driven relative to the lens barrel to decenter the photographing optical axis, a position detection means that detects the position of the correction optical system, and detects vibrations. In an anti-vibration camera, the anti-vibration camera is equipped with a vibration-proofing means for driving the correction optical system based on an output from the vibration-detecting means and an output from the position-detecting means. An anti-vibration camera characterized by having an anti-vibration sensitivity changing means for changing the ratio.