JPH0575912A - Video camera equipment - Google Patents

Abstract

(57) [Abstract] [Purpose] In a video camera device having an electronic image stabilization function, erroneous correction due to a mounting error of a detector for detecting shake is prevented. [Structure] The detection output Mv of the vertical shake detector 4 and the detection output Mh of the horizontal shake detector 5 are supplied to a shake calculating circuit 6, and these are vector-calculated to obtain a true vertical shake detection signal MV. A true horizontal shake detection signal MH is generated. On the other hand, the output video signal of the image sensor 2 is supplied to the time axis conversion circuit 3, and the time axis in the vertical direction and the time axis in the horizontal direction are changed by the shake detection signal MV and the shake detection signal MH. Here, even if the vertical shake detector 4 and the horizontal shake detector 5 have an installation error and their detection axes deviate from the true vertical and horizontal directions, the shake calculation circuit 6 performs vector calculation to make this installation. The shaking detection signals MV and MH are calculated by removing the error component due to the error. As a result, a touch-free image is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video camera device using an image pickup device, and more particularly to a video camera device having an electronic image stabilization function.

[0002]

2. Description of the Related Art With the spread of video camera devices in recent years,
Development is underway to reduce the size and weight. But,
As miniaturization progresses, camera shake tends to occur during shooting,
When the captured video is played back, image shake due to camera shake has become noticeable.

Therefore, various camera shake correction means for video camera devices have been proposed. One of them is, for example,
IEEE Trans. on CE, Vol. 35, N
o. 4, Nov. M. 1989. Oshima, e
t. al. By "VHS CAMCORDER wi
th ELECTRONIC IMAGE STABI
A method using an angular velocity sensor is known, as described in a paper entitled "LIZER". In this system, a video camera device is provided with a camera shake detection circuit, and the image pickup element and the optical lens are moved by an amount capable of canceling the camera shake according to the detection result of the detection circuit. That is, two angular velocity sensors are used as means for detecting the amount of vertical and horizontal movement due to camera shake. One angular velocity sensor detects the amount of vertical movement due to camera shake, and the other angular velocity sensor uses the same horizontal direction. The amount of movement of the image sensor is detected, and the image sensor and the optical lens are moved so as to cancel the movement of the image due to camera shake according to the respective detection results.

[0004]

However, the above-mentioned prior art has the following problems. That is, FIG.
In (a), A is the detection axis of the angular velocity sensor, and V and H are vertical and horizontal components of motion due to camera shake, respectively, and the angle of the vertical component V of motion with respect to the detection axis A is θ, with respect to the detection axis A. The angle of the horizontal component H of the movement is δ
Then, the detection sensitivity of the angular velocity sensor changes according to the angles θ and δ, as shown in FIG. Therefore, for example, if the angular velocity sensor attached to detect a vertical motion component is tilted in the horizontal direction due to an attachment error, it has detection sensitivity in the horizontal direction as well.
Even if the camera shake occurs only in the horizontal direction, the movement is detected. At this time, the camera shakes in the vertical direction, but falsely detects that the camera shakes in the vertical direction, and the camera shake is erroneously corrected, and the image on the screen shakes in the vertical direction. It will be.

Further, even when the angular velocity sensor is mounted at a position where its output gain is lowered, it is impossible to accurately detect the amount of vertical and horizontal movement components due to camera shake.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problem and to provide a video camera device capable of accurately eliminating the shaking of an image with respect to the shaking in an arbitrary direction.

[0007]

In order to achieve the above object, the present invention provides a plurality of shake detectors for detecting shakes of image pickup devices in different directions, and outputs from the shake detectors respectively. A shake calculation circuit that calculates the shake in the horizontal or vertical direction of the image from the shake detection signal, and the horizontal direction or the horizontal direction of the video signal output from the image sensor according to the shake in the horizontal direction or the vertical direction calculated by the shake calculation circuit. And a time axis conversion circuit for converting the time axis in the vertical direction.

[0008]

The detected outputs of the plurality of shake detectors are vector-calculated by the shake calculation circuit to generate a shake detection signal representing the true vertical and horizontal shake components. The time axis conversion circuit converts the time axis of the output video signal of the image sensor according to these shake detection signals and corrects the shake of the image due to camera shake. Even if the error deviates from the true vertical or horizontal direction, the vector calculation in the shake calculation circuit cancels the influence of the attachment error, and the shake detection signal not affected by the attachment error can be obtained. Therefore, even if there is a mounting error in the shake detector, it is not affected by the error and the shake of the image due to camera shake can be accurately corrected.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a video camera device according to the present invention, in which 1 is an optical lens, 2 is an image sensor, 3 is a time axis conversion circuit, 4 is a vertical shake detector, and 5 is a vertical shake detector.
Is a horizontal shake detector, and 6 is a shake calculation circuit.

In FIG. 1, light from a subject (not shown) enters the light receiving surface of the image sensor 2 through the optical lens 1,
As a result, a subject image is formed on this light receiving surface. The image pickup device 2 picks up the subject image and outputs an electric signal according to the subject image. This electric signal is supplied to a signal processing circuit (not shown) through the time axis conversion circuit 3 and becomes a video signal.

On the other hand, a vertical shake detector 4 and a horizontal shake detector 5 are provided, and when shake occurs due to camera shake during shooting, the vertical shake detector 4 causes the vertical component of the shake. Is output from the horizontal shake detector 5, and the horizontal shake detector 5 outputs a detection signal Mh corresponding to the horizontal component of the shake. The detection signals output from the vertical shake detector and 2 are vector-calculated by the shake calculating circuit 6 to generate a vertical shake detection signal MV and a horizontal shake detection signal MH. As described above, when the shake detection signals MV and MH are obtained by vector calculation, even if the vertical shake detector 4 and the horizontal shake detector 5 are attached at positions displaced by an attachment error, these shake detection signals MV are detected. , MH accurately represent the amount of shaking in the vertical and horizontal directions, respectively.

These shake detection signals MV and MH are supplied to the time base conversion circuit 3. The time axis conversion circuit 3 converts the vertical and horizontal time axes of the electric signal from the image pickup device 2 so as to cancel the shake of the image due to the shake by the shake detection signals MV and MH.

FIG. 2 is a block diagram showing a specific example of the fluctuation calculation circuit 6 in FIG. 1, in which 7 is a coefficient generator, and 8 to
Reference numeral 11 is a multiplier, and 12 and 13 are adders. In the figure, the detection signal Mv output from the vertical shake detector 4
Is supplied to the multipliers 8 and 9, and the detection signal Mh output from the horizontal shake detector 5 is supplied to the multipliers 10 and 11. The multiplier 8 multiplies the detection signal Mv by the coefficient α1 from the coefficient generator 7, and the multiplier 9 multiplies the detection signal Mv by the coefficient α3 from the coefficient generator 7. The multiplier 10 multiplies the detection signal Mh by the coefficient α2 from the coefficient generator 7, and the multiplier 11 multiplies the detection signal Mh by the coefficient generator 7.
Is multiplied by the coefficient α4.

The coefficient α1 output from the coefficient generator 7 is shaken only in the vertical direction as a result of the vertical shake detector 4 (FIG. 1) tilting in the horizontal direction due to a mounting error. It is a coefficient for correcting the detection that the shake occurs in the horizontal direction. The coefficient α2 output from the coefficient generator 7 causes the horizontal shake detector 5 (FIG. 1) to tilt in the vertical direction due to a mounting error, so that the shake occurs in the vertical direction even if the shake occurs only in the horizontal direction. It is a coefficient for correcting the above detection.

The coefficient α output from the coefficient generator 7
3 and α4 are coefficients for correcting the shake detectors 4 and 5 when the shake detectors 4 and 5 are mounted at positions where these gains are reduced due to their mounting errors.

The outputs of the multipliers 8 and 11 are added by the adder 12, and the outputs of the multipliers 9 and 10 are added by the adder 13. The output of the adder 12 is the vertical shake detection signal M described above.
V, and the output of the adder 13 is the horizontal shake detection signal MH. Therefore, these shaking detection signals MV, M
H is obtained by the vector operation shown by the following equation. MH = α1 · Mv + α4 · Mh (1) MV = α3 · Mv + α2 · Mh (2) Based on the vertical shake detection signal MV and the horizontal shake detection signal MH obtained in this way, FIG. The time axis conversion circuit 3 converts the vertical and horizontal time axes of the electric signal from the image pickup element 2 to cancel the shaking of the image due to the shaking of the hand.

FIG. 3 is an explanatory diagram showing that the error in mounting the shake detectors 4 and 5 is removed by the above vector calculation. In the figure, the actual vertical direction is V, the actual horizontal direction is H, the detection axis of the vertical shake detector 4 is AV, and the detection axis of the horizontal shake detector 5 is AH. Further, it is assumed that the detection axes AV and AH are deviated from the vertical direction and the horizontal direction due to an attachment error of the vertical shake detector 4 and the horizontal shake detector 5, respectively. If a shake M occurs in an arbitrary direction in such a state, the vertical shake detector 4 detects the component Mv of the shake M in the direction of the detection axis AV, and the horizontal shake detector 5 detects the shake M. The component Mh in the direction of the detection axis AH is detected. However, these detection axes A
Since V and AH do not match the vertical direction V and the horizontal direction H, respectively, the component Mv is not the vertical direction V component MV of the swing M, and the component Mh is the horizontal direction H component MH of the swing M.
is not.

By the way, assuming a vector in which the swing M, the component Mv, the component Mh, the vertical direction V component MV of the swing M, and the horizontal direction H component MH are used as absolute values and their directions are taken into consideration, calculation of these vectors is performed. Thus, the vertical component V component MV and the horizontal component H MH of the shake M can be obtained.

That is, when the fluctuation M and the vector of these components are expressed by adding a dash to these symbols, as is apparent from FIG. 3, M ′ = Mv ′ between the vector M ′ and the vector of each component. The relational expression + Mh '= MV' + MH 'can be established. For this purpose, the above equations (1) and (2) need to be satisfied at the same time, and the coefficient generator 7 of FIG. 2 has the vertical direction of the detection axis AV of the vertical shake detector 4 so that these expressions are satisfied at the same time. The coefficients α1, α2, α3, and α4 are generated according to the amount of deviation from the direction V and the amount of deviation of the detection axis AH of the horizontal shake detector 5 from the horizontal direction H, respectively.

The coefficients α1, α2, α3, and α4 are shift amounts of the detection axis AV of the vertical shake detector 4 from the vertical direction V, and shift amounts of the detection axis AH of the horizontal shake detector 5 from the horizontal direction H. It can be obtained by the following method. Now, assuming that the MV shake is given only in the vertical direction V, the detection output of the vertical shake detector 4 at this time is Mvv, and the horizontal shake detector 5
Since the detection output of Mhv is MH = 0, MV = α3 · Mvv + α2 · Mhv (3) 0 = α1 · Mvv + α4 · Mhv (4) from the above equations (1) and (2). And the swing of MH is given only in the horizontal direction V, the detection output of the vertical swing detector 4 at this time is M
If vh and the detection output of the horizontal shake detector 5 are Mhh, then MV = 0. Therefore, according to the above equations (1) and (2), 0 = α3 · Mvh + α2 · Mhh (5) MH = α1・ Mvh + α4 ・ Mhh (6) holds. Therefore, from the equations (3) and (5), the coefficient α2,
Since α3 can be obtained, the coefficients α1 and α4 can be obtained from the equations (4) and (6).

As described above, even when the shake detector is mounted at an inclination due to a mounting error, by using the vector calculation, it is possible to accurately correct the camera shake by using the detection output of the shake detector. ..

[0022]

As described above, according to the present invention,
By calculating the shake detection signals output from multiple shake detectors by vector, even if there is a mounting error in the shake detector, it is possible to obtain a shake correction signal that is not affected by this mounting error, and the shake Can be corrected.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a video camera device according to the present invention.

FIG. 2 is a block diagram showing a specific example of a shake calculation circuit in FIG.

FIG. 3 is an explanatory diagram showing a vector operation of the shake calculation circuit shown in FIG.

FIG. 4 is a diagram showing a change in detection sensitivity due to an attachment error of an angular velocity sensor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical lens 2 Image sensor 3 Time axis conversion circuit 4 Vertical direction shake detector 5 Horizontal direction shake detector 6 Shake calculation circuit 7 Coefficient generator 8-11 Multiplier 12, 13 Adder

Claims (2)

[Claims] 1. An image pickup device for converting an image formed by an optical lens into a video signal, a plurality of shake detectors for detecting shakes of the image pickup device in different directions, and each of the shake detectors. A shake calculation circuit that calculates the shake in the horizontal direction or the vertical direction of the image from the output shake detection signal, and the video signal of the video signal according to the shake in the horizontal direction or the vertical direction calculated by the shake calculation circuit. With a time axis conversion circuit that converts the horizontal or vertical time axis,
A video camera device, characterized in that the time axis conversion of the time axis conversion circuit can cancel the fluctuation of the image of the output video signal of the image pickup device. 2. The shake detector according to claim 1, wherein there are two shake detectors, and one of the two shake detectors has a shake detection direction in a horizontal direction of the image and the other shake detector. A video camera device characterized in that directions thereof are substantially aligned with a vertical direction of the image.