JPH08331439A - Hand shake correcting device - Google Patents

Abstract

PURPOSE: To provide a hand shake correcting device capable of preventing the blurring of an image caused by the starting characteristics, etc., of the hand shake correcting device at the time of power source start by replacing the output signal of a shake amount detecting means with a fixed signal when a frequency detecting means detects any frequency out of a prescribed frequency range in the output signal of the shake amount detecting means. CONSTITUTION: Based on the output signal of a shake amount detecting means 1 for detecting the shake amount of the image caused by the shake of the main body of a video camera, a correct signal generating means 2 generates a correct signal for correcting the blurring of the image. Frequency detectors 13y and 13p receive the output signal of the shake amount detecting means 1 through non-linear integrators 11y and 11p and detect whether the output signal is in the prescribed frequency range or not. When any frequency out of the prescribed frequency range is detected, switches 14y and 14p are switched to the side of fixed value outputters 12y and 12p and the output signal of the shake amount detecting means 1 is fixed. Thus, the hand shake correcting device for preventing the blurring of the image caused by the starting characteristics., etc., of the hand shake correcting device at the time of power source start is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image stabilizer suitable for use in, for example, a handy type video camera device.

[0002]

2. Description of the Related Art Today, handy type video camera devices provided with a so-called CCD image sensor are in widespread use.

The handy-type video camera device, which is small and lightweight, has a problem that camera shake is likely to occur during image pickup. If camera shake occurs during the above-described image pickup, for example, when a zoomed-up image is played back, a fine “shaking” occurs in the played back image, making it very difficult to see the played back image.

As a method for correcting the "shake" due to the above-mentioned camera shake to make the reproduced image easier to see, there is known a technology for correcting the camera shake by a camera shake correction device provided in a video camera device. In this camera shake correction apparatus, as a correction means for correcting the camera shake, there is known one that adopts a method of correcting by image processing or a method of correcting by optical processing.

A memory control system and a CCD drive control system are known as correction means for correcting camera shake by the above image processing.

In the above memory control system, when camera shake is detected, a part of a video signal obtained by picking up an image of a subject is taken out as an image frame and moved so that the image frame of the previous field and the image frame of the current field are aligned with each other. The two image frames are matched with each other, and the correction range is secured by enlarging the image of the image frame portion. When this image is enlarged, the image signal is enlarged beyond the resolution of the CCD image sensor, so that the quality of the reproduced image is deteriorated. This deterioration in image quality becomes larger as the correction range becomes wider. Therefore, in this method, the image quality is deteriorated and the correction range cannot be widened. However, the correction means adopting this method is suitable for a small and low-priced video camera device because it is composed of only an IC.

In the CCD drive control system, when a camera shake is detected, a video signal obtained by picking up an image of a subject is C
The correction is performed by changing the timing of reading from the CD image sensor. In this method, the correction range is ensured by increasing the number of pixels of the CCD image sensor, so that the shake correction is performed even when “shaking” appears to be magnified like a subject photographed at high magnification. Therefore, it is necessary to increase the number of pixels. However, if the number of pixels is increased so as to sufficiently perform the camera shake correction due to the enlarged “vibration”, the CCD image sensor and the CCD
The peripheral circuits of the image sensor are large and expensive, and are not practical. For this reason, in the correction means actually adopting this method, the number of pixels for sufficiently correcting the camera shake of the enlarged "shake" is not secured, so that the camera shake of the enlarged "shake" is corrected. There is a discontinuous portion in the image of the reproduced image that is being generated due to camera shake. However, the camera shake correction is performed without any problem at a normal photographing magnification, and since it is composed of only an IC, it is suitable for a small and low-priced video camera device.

Gimbal mechanical system and active prism system are known as the correction means for correcting the camera shake by the optical processing.

When the camera shake is detected, the gimbal mechanical system moves the entire lens unit in a direction for canceling the camera shake to correct the camera shake. With this method, the resolution is not deteriorated and the correction range can be made relatively wide, but since the entire lens unit is moved, the mechanism becomes large and the power consumption also becomes large. Therefore, the correction means adopting this method is suitable when high resolution is desired even if the size is somewhat large.

When the camera shake is detected, the active prism system corrects the camera shake by moving only a part of the lens unit in the direction of canceling the camera shake. Therefore, in this method, the power consumption is small, the miniaturization is easy, the resolution is not deteriorated, and the correction range is relatively wide. By preventing camera shake by this active prism system, it is possible to realize a handy type video camera device that is high in image quality, small in size and light in weight, without causing "jitter" in reproduced images.

The active prism used in this active prism system connects two glass plates with a stretchable bellows made of a special film, and has an optical refractive index almost the same as that of the above two glass plates. It is formed by injecting the liquid. This active prism includes the objective lens provided on the front surface of the video camera body for guiding the subject image from the subject to the CCD camera, and the objective lens and the CCD image sensor for guiding the subject image to the CCD image sensor. In each of the two glass plates provided between the two glass plates, the inclination angle (hereinafter referred to as the apex angle) with respect to each of the different vertical or horizontal directions of the video camera body. It is variable to correct camera shake. The injected liquid may generate bubbles under a low atmospheric pressure and cannot sufficiently perform camera shake correction, but it can be used without problems under a normal atmospheric pressure.

All of these correction means for correcting camera shake are for correcting camera shake when camera shake is detected. An angular velocity detection method is known as a shake amount detecting means for detecting this camera shake.

The above-mentioned angular velocity detection method detects an angular velocity by using an angular velocity sensor such as a piezoelectric vibrating gyro. It requires a larger space than an IC because it is a mechanical component, but it malfunctions depending on the illuminance condition and the like. Without being detected in real time. For this reason, the shake amount detecting means adopting this method is suitable for a video camera device that accurately performs camera shake correction.

The camera shake correction device used in the handy type video camera device includes a camera shake amount detecting means for detecting a camera shake of an image caused by a camera shake of the video camera by an angular velocity detecting method, and an output signal of the camera shake amount detecting means. A correction signal generating means for generating a correction signal based on the above, and a method by image processing such as a memory control method and a CCD drive control method,
Alternatively, it includes a correction unit that corrects a camera shake based on a correction signal generated by the correction signal generation unit by an optical processing method such as a gimbal mechanical method or an active prism method.

By the way, the angle of the video camera device changes not only by hand shake, but also by panning (a method of taking a picture by swinging the camera left and right) / tilting (moving the camera from top to bottom or from bottom to top). It may be due to camera work such as (shooting method). For the above camera work,
Generally, there are slow ones and quick ones, and the speed change becomes large at the beginning and the end of the camera work, so that frequency components of 0.5 Hz or less and 15 Hz or more are generated due to the camera work. To be done.

Further, there is a width due to individual difference in the frequency band of this camera work.

The frequency component of the camera shake is 5 to 8 Hz when the photographer photographs on a stationary body without performing camera work. When the photographer photographs on a moving body, for example, in a car, the main frequency component of camera shake shifts to 20 to 25 Hz on the high frequency side. Further, there is a width due to individual differences in the frequency band of this camera shake.

In the above-mentioned image stabilization apparatus having the above-mentioned structure, generally, 2 to 30H is taken into consideration in consideration of a case where a camera shake occurs when a photographer performs a camera work on a moving body.
In the frequency range of z, the camera shake is corrected by performing servo control so as to cancel the shake of the image due to the camera shake without correcting the camera shake due to the camera work. Therefore, the reproduced image of the video camera device is an image that is easy to see without causing “shaking” due to camera shake.

[0019]

By the way, when the power source of the video camera device is turned on, it takes some time for the operations of the shake amount detecting means and the correction signal generating means to converge to a steady state.

Therefore, in the correction means, before the steady state is converged, an image which is not actually subjected to "jitter" is subjected to the camera shake correction processing based on the output signal of the correction signal generation means. Therefore, there is a problem that the image moves.

In view of the above problems, it is an object of the present invention to provide a camera shake correction device that prevents image shake caused by the rising characteristics of the camera shake correction device when the power is turned on.

[0022]

SUMMARY OF THE INVENTION A camera shake correction apparatus according to the present invention includes a shake amount detecting means for detecting the shake amount of an image caused by a shake of a video camera body, and an output signal of the shake amount detecting means. A correction signal generating means for generating a correction signal for correcting the shake of the image based on the frequency, a frequency detecting means for detecting whether or not the frequency of the output signal of the shake amount detecting means is within a predetermined frequency range, and the frequency Depending on the fixed signal setting means for replacing the output signal of the shake amount detecting means with a predetermined fixed signal when the detecting means detects a frequency outside the predetermined frequency range, and the correction signal generated by the correction signal generating means. And a correction unit that corrects the shake of the image.

[0023]

In the image stabilization apparatus according to the present invention, the frequency detection means replaces the output signal of the shake amount detection means with a predetermined fixed signal, and the correction signal generation means generates a correction signal based on the fixed signal. The correction means holds the predetermined state based on the correction signal.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the image stabilizing apparatus according to the present invention will be described below with reference to FIG. The camera shake correction device according to the present invention is provided, for example, for camera shake correction of a handy type video camera device. The camera shake correction device shown in FIG. 1 is an example of the camera shake correction device when the angular velocity detection method is adopted as the shake amount detection means and the active prism method is adopted as the correction means.

The camera shake correction apparatus shown in FIG. 1 corrects the shake of an image by a shake amount detecting means 1, a correction signal generating means 2 which generates a correction signal based on a detection output of the shake amount detecting means 1. The correction means 3 is provided.

The shaking amount detecting means 1 adopts an angular velocity detecting system composed of a piezoelectric vibration gyro or the like,
A shake amount detecting means 1y which is provided with its detection surfaces facing in the vertical direction and the horizontal direction of the video camera main body and detects an angular velocity caused by a roll direction (hereinafter referred to as a yawing direction) which is the Y direction, respectively. It has a shake amount detecting means 1p for detecting an angular velocity caused by a rolling direction (hereinafter referred to as a pitching direction) which is a P direction.

Angular velocity sensors 6y and 6p in the yawing direction and the pitching direction are provided in the shake amount detecting means 1y and 1p,
Filters 7y and 7p for cutting harmonic components of output signals of the angular velocity sensors 6y and 6p, and the filters 7y and 7y,
A / D converters 8y and 8 for sampling the output signal of 7p at a sampling frequency sufficiently higher than the pass band frequency of the correction signal generating means 2 and performing A / D conversion.
p and.

The angular velocity sensors 6y and 6p in the yawing direction and the pitching direction are arranged near the active prism 21 of the correcting means 3 described later so as to detect the angular velocities in the yawing direction and the pitching direction of the video camera body. It

The shaking amount detecting means 1 having the above-described structure detects the angular velocity due to the shake in the yawing direction and the pitching direction of the video camera body by using the angular velocity sensors 6y and 6p, and the detected output is A / D converter. 8y, 8p
Then, the signal is A / D converted for each sampling frequency and sent to the correction signal generating means 2.

The correction signal generating means 2 generates an angle signal based on the digital shake amount in the yawing direction and the pitching direction supplied from the shake amount detecting means 1y, 1p,
Nonlinear integrators 11y and 11p for transmitting the angle signal,
Fixed value output devices 12y and 12p for transmitting a predetermined fixed signal
And frequency detectors 13y and 13p for detecting the frequencies of the output signals of the shake amount detecting means 1y and 1p, and the nonlinear integrator 1 based on the detection results of the frequency detectors 13y and 13p.
1y, 11p or switches 14y, 14p for sending output signals of fixed value output devices 12y, 12p, and the switch 1
D / A converters 15y and 15p for D / A converting the output signals of 4y and 14p into analog angle signals, and D
It has mix circuits 16y and 17y to which the analog angle signals supplied from the / A converters 15y and 15p are supplied, and mix circuits 16p and 17p.

The non-linear integrators 11y and 11p integrate the sum of products of the digital angular velocity signals supplied from the A / D converters 8y and 8p of the shake amount detecting means 1 and the sampling time of the angular velocity signals. Then, the angle resulting from the shake of the video camera body in the yawing direction and the pitching direction is calculated, and the angle signal based on the angle is sent to the switches 14y and 14p.

The fixed value output devices 12y and 12p send fixed signals output from the shaking amount detecting means 1y and 1p when the shaking angle of the video camera body is zero.
The fixed value output devices 12y and 12p are connected to the switches 14y and 14p from the frequency detectors 13y and 13p by Lo.
When the w signal is supplied, it is connected to the switches 14y and 14p to convert the fixed signal to the D / A converter 15
y, 15p is transmitted.

The frequency detectors 13y and 13p are the shake amount detecting means 1y, when the power source of the video camera device is turned on.
The frequency of the output signal of 1p is detected, the High signal is transmitted when the frequency of the output signal is 2 to 30 Hz, and the Low signal is transmitted otherwise. In this way, the frequency detectors 13y and 13p have the fluctuation amount detecting means 1y and 1p.
It functions as frequency detecting means for detecting the frequency of the p output signal.

The switches 14y and 14p send the angle signals which are the output signals of the non-linear integrators 11y and 11p when the High signals are supplied from the frequency detectors 13y and 13p, and the frequency detectors 13y and 13p output the angle signals. When the Low signal is supplied, the fixed signal that is the output signal of the fixed value output devices 12y and 12p is transmitted. In this way, the fixed value output devices 12y and 12p and the switches 14y and 14p function as fixed signal setting means.

The nonlinear integrators 11y and 11p, the fixed value output devices 12y and 12p, the frequency detectors 13y and 13p and the switches 14y and 14p are the microcomputer 3
It is composed of 0.

In the D / A converters 15y and 15p, the angle signals or the fixed signals supplied from the switches 14y and 14p are D / A converted, and the mix circuits 16y and 1p.
Send to 6p.

The mix circuits 16y and 16p mix the output signals of the D / A converters 15y and 15p and the apex angle signal supplied from the correction means 3, and send the mixed signals to the mix circuits 17y and 17p.

The mix circuits 17y and 17p mix the mixed signal supplied from the mix circuits 16y and 16p with the apex angular velocity signal supplied from the correction means 3 to generate a correction signal, and the correction signal is supplied to the correction means. Send to 3.

In the correction signal generating means 2 having the above configuration, the yaw signals supplied from the shake amount detecting means 1y, 1p are supplied by the non-linear integrators 11y, 11p except when the Low signal is sent from the frequency detectors 13y, 13p. Direction and pitching direction digitized angular velocity signals are converted into angle signals, and the angle signals are converted into D / A converters 15y, 1
Convert to analog signal at 5p, mix circuit 16y,
In 16p, the analog angle signal and the apex angle position signal supplied from the correcting means 3 are mixed to generate a mixed signal, and in the mixing circuits 17y and 17p, the mixed signal and the correcting means 3 are mixed.
The vertical angular velocity signals supplied from the above are mixed to generate correction signals in the yawing direction and the pitching direction, and the correction signals are sent to the correction means 3.

From the frequency detectors 13y and 13p to L
When the ow signal is transmitted, the fixed signal is transmitted to the switch 1
The fixed value output devices 12y and 12p via 4y and 14p
To the D / A converters 15y and 15p, and the mix circuits 17y and 17p send out a correction signal in which the fixed signal is mixed with the apex angle signal and the apex angular velocity signal supplied from the correcting means 3.

The correcting means 3 adopts an active prism system, and an active prism 21 arranged in front of an image receiving portion of a CCD image sensor for receiving a subject image, and the active prism 21. Position detection unit 2 for detecting the vertical angle position in the yawing direction and the pitching direction
7y and 27p, speed detectors 28y and 28p that detect the changing speed of the apex angle, and a drive unit 29y that variably drives the apex angle.
29p.

The active prism 21 is a glass plate 22 which is rotatable in the yawing direction and the pitching direction.
y and 22p, a bellows 23 made of a special film that stretchably connects the glass plates 22y and 22p, and the bellows 2
The glass plate 22y, 22p, which is injected between the three glass plates 22y, 22p, is filled with the liquid 24 having the same optical refractive index as that of the glass plate 22y, 22p.

The glass plate 2 of this active prism 21
By changing the apex angles of 2y and 22p in the direction for canceling the camera shake, the camera shake is canceled in the subject image received by the CCD image sensor via the active prism 21, and "jitter" occurs. The subject image will not be allowed.

The position detecting portions 27y and 27p are located on the side surfaces of the glass plates 22y and 22p of the active prism 21, and the yawing directions of the glass plates 22y and 22p,
It is composed of a photo sensor that detects the position of the vertical angle in the pitching direction.

The speed detecting units 28y and 28p detect the moving speed of the position of the apex angle detected by the position detecting units 27y and 27p, thereby detecting the apex angles of the glass plates 22y and 22p of the active prism 21. Detects fluctuating speed.

The drive unit 29y is a mix circuit 17y.
An inverting circuit that inverts the correction signal supplied from the
And a drive circuit for displacing the glass plate 22y of the prism 21 in the yawing direction.

In the drive unit 29y, the mix circuit 17
Based on the correction signal supplied from y, the driving circuit drives the apex angle of the glass plate 22y of the active prism 21 in a direction for canceling camera shake.

The drive unit 29p has the same structure as the drive unit 29y, and drives the apex angle of the glass plate 22p of the active prism 21 in a direction for canceling camera shake.

The correction means 3 having the above configuration is supplied with the correction signal from the mix circuits 17y and 17p via the mix circuits 16y and 16p of the correction signal generation means 2. In the drive units 29y and 29p to which the correction signal is supplied, the apex angle of the glass plates 22y and 22p is changed in the direction in which the camera shake is canceled based on the correction signal to correct the camera shake. Here, the frequency detectors 13y, 1
When the Low signal is transmitted from 3p, the fixed signals which are the angle signals when the angle is zero are supplied from the mix circuits 17y and 17p, and the drive units 29y and 29p.
The state of is retained.

Further, the position of the apex angle and the changing speed of the glass plates 22y and 22p of the active prism 21 are corrected by the correcting means 3.
Position detectors 27y and 27p and speed detectors 28y and 28
The mix circuit 1 of the correction signal generation means 2 detected by p
6y, 17y and the mix circuits 16p, 17p.

In the image stabilization apparatus having the above configuration, when the power of the video camera apparatus is turned on, if the output signal of the shake amount detection means 1 is outside the range of 2 to 30 Hz due to camera shake or camera work, Low signals are sent from the frequency detectors 14y and 14p of the correction signal signal generating means 2, and at this time, fixed signals whose angle signals are zero are sent from the switches 14y and 14p, and the mix circuits 17y and 17p. The correction signal generated based on the angle signal is supplied to the correction means 3. The correction means 3 holds the states of the drive units 29y and 29p based on the correction signal. For this reason, camera shake correction due to the rising characteristics of the camera shake correction device when the power is turned on is not performed.

In this embodiment, an example of the camera shake correction device is shown in which the angular velocity detection method is used as the shake amount detection means and the active prism method is used as the correction means. The present invention is not limited to the method, and the hand shake correction apparatus of the present invention uses the image processing such as the memory control method and the CCD drive control method when the hand shake is detected by the detection unit such as the shake amount of the angular velocity detection method. Or a handheld type video with high image quality that is small in size and light in weight, and that does not cause "jitter" due to shaking in the reproduced image by correcting camera shake by means of optical processing methods such as gimbal mechanical method, active prism method, etc. A camera device can be realized.

[0053]

As described in detail above, in the image stabilization apparatus of the present invention, the output signal of the shake amount detecting means is replaced by a predetermined fixed signal by the frequency detecting means, and the fixed signal is changed by the correcting signal generating means. Based on this, a correction signal is generated. The correction means holds the predetermined state based on the correction signal. Therefore, when a frequency other than the predetermined frequency due to the rising characteristics of the image stabilization device at power-on is detected by the frequency detection means, the correction means is fixed in a predetermined state to prevent image shake. It is possible to provide a camera shake correction device that operates.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an image stabilization apparatus according to the present invention.

[Description of Reference Signs] 1 shake amount detecting means 2 correction signal generating means 3 correcting means 12y, 12p fixed value output device 13y, 13p frequency detector 14y, 14p switch

Claims (1)

[Claims] 1. A shake amount detecting means for detecting a shake amount of an image caused by a shake of a video camera body, and a correction signal for correcting the shake of the image based on an output signal of the shake amount detecting means. Correction signal generating means for generating, a frequency detecting means for detecting whether or not the frequency of the output signal of the shake amount detecting means is within a predetermined frequency range, and a frequency outside the predetermined frequency range is detected by the frequency detecting means. And a fixed signal setting means for replacing the output signal of the shake amount detecting means with a predetermined fixed signal, and a correcting means for correcting the shake of the image according to the correction signal generated by the correction signal generating means. Image stabilization device.