JPH10108062A - Image stabilization device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To correct image shake properly without giving an uncomfortable feeling to an operator even when intentional panning or tilting is performed. SOLUTION: An operator turns on an X-direction mode changeover switch 17X when intentionally performing panning, and turns on a Y-direction mode changeover switch 17Y when intentionally performing tilting. The output signal of the X-direction gyro sensor for detecting the angular velocity in the X direction of the video camera is A / D-converted by the A / D converter 41X, the low-frequency component is removed by the HPF 51, and the angle signal is integrated by the integrating unit 52. Is input to the correction angle limiting unit 54. When the X-direction mode changeover switch 17X is turned on, the correction angle limiting unit 54 limits the correction angle in the X direction. The same applies to the Y direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image blur correcting device for correcting an image blur in an image pickup device such as a video camera.

[0002]

2. Description of the Related Art In recent years, in imaging devices such as video cameras,
2. Description of the Related Art An image blur correction device for correcting an image blur caused by a vibration such as a hand shake of an operator has been put to practical use. As one method of image shake, a detection device for detecting shake of the image pickup device is provided in the image pickup device, and the bending angle of the optical axis is changed in the image pickup optical system, for example, by changing the vertex angle of a prism. There is a method in which a correction optical system capable of changing the optical axis is provided, and the servo circuit controls the correction optical system based on the output of the detection device to control the bending angle of the optical axis. In this method, an angular velocity sensor such as a gyro sensor is used as a detection device for detecting the shake of the imaging device.

[0003]

As described above, when a shake is detected using a detecting device such as an angular velocity sensor, a signal output from the detecting device includes a shake to be corrected such as a hand shake. In addition to the signal caused by the above, a signal caused by intentional pan (shaking the video camera or the like in the horizontal direction) or tilt (shaking the video camera or the like in the vertical direction) is also included. It is not preferable that the image shake correction is performed at the time of intentional pan / tilt, since the image shake particularly occurs after the end of the pan / tilt, giving an uncomfortable feeling to the operator. Therefore, by performing processing such as filtering, the signal component caused by the shake to be corrected and the signal component caused by the intentional pan / tilt are separated from the output signal of the detection device, and the intentional pan / tilt is separated. At times, it has been proposed to perform control so that the image blur correction operation is suppressed. In general, the frequency components of the image blur are distributed in about 0.5 to 30 Hz. However, the level of the output signal of the detection device at the time of intentional fast pan / tilt becomes larger than that at the time of camera shake, so・ Tilt detection is easy. However, especially at the time of slow pan / tilt around 1 Hz, both the frequency and the level of the signal component fall within the range of the frequency and the level of the signal component caused by a shake to be corrected such as a camera shake. In the above-mentioned processing, it is difficult to completely separate a signal component caused by a shake to be corrected from a signal component caused by intentional pan / tilt.

Therefore, a method is conceivable in which the operator instructs intentional pan / tilt using a switch or the like, and restricts the image blur correction operation in accordance with the instruction. However, in this method, at the time of intentional panning, the image shake correction operation is also restricted in the tilt direction, and even if there is image shake in the tilt direction, it cannot be corrected. In addition, the image blur correction operation is restricted also in the pan direction, and there is a problem that even if there is image blur in the pan direction, it cannot be corrected.

The present invention has been made in view of such a problem, and an object of the present invention is to make it possible to appropriately correct image shake without giving an uncomfortable feeling to an operator even when intentional panning or tilting is performed. To provide an improved image blur correction apparatus.

[0006]

SUMMARY OF THE INVENTION An image shake correcting apparatus according to the present invention is based on shake detection means for detecting a shake which causes image shake in both the vertical and horizontal directions, and a detection output of the shake detection means. Correction means capable of correcting image shake in both the vertical and horizontal directions, instruction means for instructing that the correction by the correction means be independently restricted in the vertical and horizontal directions, and the instruction means A correction restricting means is provided for independently restricting the correction by the correcting means in the vertical and horizontal directions in accordance with the instruction.

In this image shake correcting apparatus, the shake detecting means detects a shake which causes image shake in both the vertical direction and the left and right direction. The image shake is corrected in both the left and right directions. Also,
According to the instruction by the instruction means, by the correction restricting means,
The correction by the correction means is restricted independently in the vertical and horizontal directions.

[0008]

Embodiments of the present invention will be described below in detail with reference to the drawings.

First, a schematic configuration of a video camera including an image blur correction device according to the present embodiment will be described with reference to FIGS. FIG. 2 shows a schematic configuration of the video camera viewed from above, and FIG. 3 shows an appearance of the video camera viewed from the side. The video camera includes a housing 10, in which an imaging device 11 using, for example, a CCD (charge coupled device) and an imaging optics (not shown) for forming a subject image on the imaging device 11. A system and a video amplifier 12 for processing an output signal of the image sensor 11 and converting the signal into a video signal are provided. A prism block 13 for optically correcting image shake is provided in the imaging optical system. The housing 10 further includes an X-direction gyro sensor 15 for detecting an angular velocity in the X-direction of the video camera to detect a shake in the left-right direction (hereinafter, referred to as an X-direction) of the video camera. A Y-direction gyro sensor 16 that detects the angular velocity of the video camera in the Y-direction to detect a shake in the direction (hereinafter, referred to as a Y-direction) is provided. For example, an X on the side of the housing 10 is used to instruct that the image blur correction operation in the X direction is restricted when the operator intentionally pans.
A direction mode changeover switch 17X and a Y direction mode changeover switch 17Y for instructing to restrict the image shake correction operation in the Y direction when the operator intentionally tilts are provided.

FIG. 4 is a perspective view showing the structure of the prism block 13. As shown in FIG. The prism blocks 13 are both transparent,
The two glass plates 21 and 22 have the same refractive index and are formed, for example, in a rectangular shape so that the X-direction correction glass plate 21 and the Y-direction correction glass plate 22 face the two glass plates 21 and 22.
A bellows 23 that flexibly connects between the glass plates 22 and 22 has substantially the same refractive index as the glass plates 21 and 22, and
And the liquid 2 filled in the space surrounded by the bellows 23
5 (see FIG. 2), an X-direction correction motor 26 for rotating the glass plate 21 in the X direction, and a Y-direction correction motor 27 for rotating the glass plate 22 in the Y direction. I have.

In the prism block 13, the glass plates 21 and 22, the bellows 23 and the liquid 25 constitute a prism whose apex angle is variable. When the glass plates 21 and 22 are arranged in parallel, the optical axis 19 (see FIGS. 2 and 3) from the subject 18 (see FIG. 3) to the image sensor 11 is not bent by the prism block 13, but is corrected in the X direction. When the glass plate 21 is turned by the motor 26 for use to make the glass plates 21 and 22 non-parallel, the optical axis 19 is bent in the X direction by the prism block 13 and the glass plate 22 is When the glass plates 21 and 22 are turned to be non-parallel, the optical axis 19 is bent in the Y direction by the prism block 13. The bending direction and angle of the optical axis depend on the rotation direction and angle of the glass plates 21 and 22.

FIG. 5 is a block diagram showing a schematic configuration of a servo system of the image blur correction device according to the present embodiment.
As shown in FIG. 5A, the servo system of the image blur correction device is attached to an X-direction correction motor 26, and by detecting the rotational position of the motor 26, the angle of the X-direction correction glass plate 21 is detected. Plate angle sensor 3 for detecting
1 and the output of the X-direction gyro sensor 15 are passed through the HPF, integrated to generate an angle signal, and the angle signal is compared with the output of the glass plate angle sensor 31, and the glass plate corresponding to the difference between the two is output. A servo circuit 32 that generates an angle error signal and drives the motor 26 based on the error signal. The angle signal generated in the servo circuit 32 corresponds to the shake angle of the video camera in the X direction, and the glass plate 21 for X direction correction should be rotated in order to correct the image shake due to the shake. This is a signal corresponding to the angle.

As shown in FIG. 5B, the servo system of the image blur correction device is further mounted on a Y-direction correction motor 27, and by detecting the rotational position of the motor 27, the Y-direction correction motor 27 is rotated. The output of the glass plate angle sensor 33 for detecting the angle of the glass plate 22 and the output of the Y-direction gyro sensor 16 are passed through the HPF, and then integrated to generate an angle signal.
A servo circuit 34 that compares the angle signal with the output of the glass plate angle sensor 33, generates a glass plate angle error signal corresponding to the difference between the two, and drives the motor 27 based on the error signal. . The angle signal generated in the servo circuit 34 corresponds to the shake angle of the video camera in the Y direction, and the glass plate 22 for correcting the Y direction should be rotated in order to correct the image shake due to the shake. This is a signal corresponding to the angle.

FIG. 1 is a block diagram showing a configuration of a servo circuit in the image blur correction device according to the present embodiment. The servo circuit 32 includes an A / D conversion unit 41X that performs A / D conversion of an output signal of the X-direction gyro sensor 15, and the A / D conversion unit 41X.
An X-direction angle signal generation unit 42X that integrates an output signal of the / D conversion unit 41X to generate an X-direction angle signal; an output signal of the X-direction angle signal generation unit 42X and an output signal of the glass plate angle sensor 31; X that drives the motor 26 based on
And a direction drive control unit 43X. Similarly, the servo circuit 34 outputs the output signal of the Y-direction gyro sensor 16 to A
A / D conversion unit 41Y for performing an A / D conversion, a Y direction angle signal generation unit 42Y for integrating an output signal of the A / D conversion unit 41Y to generate a Y direction angle signal, and a Y direction angle signal generation unit A Y-direction drive control unit 43Y that drives the motor 27 based on the output signal of 42Y and the output signal of the glass plate angle sensor 33 is provided. X direction angle signal generator 42
The X and Y direction angle signal generation units 42Y are configured by, for example, a common CPU (central processing unit). C
The PU has ROM (Read Only Memory) and R
AM (random access memory) connected, CP
U realizes the functions of the X-direction angle signal generator 42X and the Y-direction angle signal generator 42Y by executing a program stored in the ROM using the RAM as a working area.

The X-direction angle signal generation section 42X and the X-direction drive control section 43X have the same configuration as the Y-direction angle signal generation section 42Y and the Y-direction drive control section 43Y. Only the section 42X and the X-direction drive control section 43X will be described in detail.

The X-direction angle signal generation section 42X is an HPF for removing low frequency components from the output signal of the A / D conversion section 41X.
51, an integrator 52 that integrates the output signal of the HPF 51 to generate an angle signal, and an X-direction mode switch 1
An X-direction mode switching detection unit 53 that detects the state of 7X, and instructs the switching of the mode of the image blur correction operation in the X direction according to the state, and according to the instruction of the X-direction mode switching detection unit 53, A mode in which the angle signal generated by the integration section 52 is output as an X-direction angle control signal without any restriction, and a mode in which the angle signal generated by the integration section 52 is restricted and output as an X-direction angle control signal. A correction angle limiter 54 that can select a mode for output is provided.

The X-direction drive control unit 43X converts the angle control signal output from the correction angle limiting unit 54 from digital to analog (hereinafter, referred to as D / A) D / A converter 5.
5, an amplifier 56 that amplifies the output signal of the glass plate angle sensor 31, an output signal of the D / A converter 55, and the amplifier 56.
A comparison circuit 57 that compares the output signal of the first and second signals with each other and generates a signal corresponding to the difference between them; an amplifier 58 that amplifies the signal generated by the comparison circuit 57 and outputs the amplified signal as a glass plate angle error signal; A motor drive circuit 59 for driving the motor 26 based on the output signal of the amplifier 58;

Next, the operation of the image blur correction apparatus according to the present embodiment will be described. In this image shake correction apparatus, the X-direction gyro sensor 15 detects the angular velocity of the video camera in the X direction, and the glass plate angle sensor 31 detects the angle of the X-direction correction glass plate 21.
Each output signal of the direction gyro sensor 15 and the glass plate angle sensor 31 is input to the servo circuit 32. Similarly, the Y-direction gyro sensor 16 detects the angular velocity of the video camera in the Y-direction, and the glass plate angle sensor 33 detects the Y-direction angular velocity.
The angle of the direction correcting glass plate 22 is detected, and each output signal of the Y-direction gyro sensor 16 and the glass plate angle sensor 33 is input to the servo circuit 34.

In the servo circuit 32, the output signal of the X-direction gyro sensor 15 is A / D converted by an A / D converter 41X.
It is D-converted and input to the X-direction angle signal generator 42X. Similarly, in the servo circuit 34, the output signal of the Y-direction gyro sensor 16 is A / D converted by the A / D converter 41Y.
It is D-converted and input to the Y-direction angle signal generator 42Y.

The operator turns on the X-direction mode switch 17X when intentionally panning, and turns off the switch at other times. Further, the operator turns on the Y-direction mode changeover switch 17Y when intentionally performing a tilt,
Turn off at other times.

Here, referring to the flowchart of FIG. 6, an X-direction angle signal generation section 42X and a Y-direction angle signal generation section 42
The operation of the CPU 45 regarding the function of Y will be described.
In this operation, the CPU 45 first sets the A / D converter 41
An output signal of the X-direction gyro sensor 15 after A / D conversion is input from X (step S101), and an HPF operation is performed on the signal by the HPF 51 to remove low frequency components (step S102). The integration unit 52 integrates the output signal of the HPF 51 to generate an angle signal (step S103). The output signal of the integration unit 52 is input to the correction angle limiting unit 54. Next, the X-direction mode changeover detection unit 53 detects the X-direction mode changeover switch 17X.
It is determined whether or not is turned on (step S10)
4). When the X-direction mode changeover switch 17X is turned on (Y), the X-direction mode switching detecting unit 53 restricts the correction angle corresponding to the bending angle of the optical axis in the X direction to the correction angle limiting unit 54. Give instructions to let. In response, the correction angle limiting unit 54 limits the correction angle (Step S105). The limitation of the correction angle may be such that the X-direction angle control signal is set to 0 so that no correction is performed, or the upper limit value of the X-direction angle control signal is made smaller than usual (for example, 1/3 to 1 to 1). 4). Then, the correction angle limiting unit 54 outputs the limited X-direction angle control signal (Step S106). Note that the limitation of the correction angle in the correction angle limiting unit 54 may be performed while the X-direction mode changeover switch 17X is on, or after the X-direction mode changeover switch 17X is turned on. It may be performed for a fixed time. The X-direction mode switching detection unit 53 determines that the X-direction mode switching switch 17X is not turned on (step S
104; N), the correction angle limiting unit 54 is instructed not to limit the correction angle. In response, the correction angle limiting unit 54 does not limit the correction angle, and outputs the output signal of the integration unit 52 as it is as the X-direction angle control signal (step S106).

Next, the CPU 45 performs the same processing in the Y direction. That is, the CPU 45 sends the A / D converted Y-direction gyro sensor 16 from the A / D converter 41Y.
(Step S107), an HPF operation is performed on this signal by the HPF to remove low frequency components (Step S108), and then the H signal is output by the integration unit.
An angle signal is generated by integrating the output signal of the PF (step S109). The output signal of the integrating section is input to the correction angle limiting section. Next, the Y-direction mode switching detector detects
It is determined whether or not the direction mode switch 17Y has been turned on (step S110). When the Y-direction mode changeover switch 17Y is turned on (Y), the Y-direction mode switching detecting unit instructs the correction angle limiting unit to limit the correction angle corresponding to the bending angle of the optical axis in the Y direction. give. In response, the correction angle limiting unit limits the correction angle (step S111), outputs a limited Y-direction angle control signal (step S112), and returns to the main routine. When the Y-direction mode changeover switch 17Y is not turned on (step S110; N), the Y-direction mode change detection unit gives an instruction not to restrict the correction angle to the correction angle limit unit. In response, the correction angle limiting unit does not limit the correction angle, outputs the output signal of the integration unit as it is as the Y-direction angle control signal (step S112), and returns to the main routine.

The operation shown in FIG. 6 is repeatedly started by a periodically generated interrupt.

The X-direction angle signal generator 42X (CPU 4
The X direction angle control signal output from 5) is input to the X direction drive control unit 43X. In the X-direction drive control unit 43X, the D / A converter 55 outputs the X-direction angle control signal to D
/ A conversion, the output signal of the glass plate angle sensor 31 is amplified by the amplifier 56, and D
The output signal of the A / A converter 55 and the output signal of the amplifier 56 are compared to generate a signal corresponding to the difference between the two, and this signal is amplified by the amplifier 58 and sent to the motor drive circuit 59 as a glass plate angle error signal. Given. And
Motor driving circuit 59 according to the glass plate angle error signal
Thereby, the motor 26 is driven. In this way,
The X-direction correction glass plate 21 is rotated in response to the X-direction shake of the video camera, and the optical axis 19 from the subject 18 to the image sensor 11 is fixed with respect to the subject 18.
Image shake in the X direction is corrected.

Similarly, the Y-direction angle signal generator 42Y (C
PU45), the Y-direction angle control signal is input to the Y-direction drive control unit 43Y, and the Y-direction drive control unit 43Y
The Y-direction angle control signal and the glass plate angle sensor 3
The motor 27 is driven based on the third output signal. In this way, the Y-direction correcting glass plate 22 is rotated in response to the Y-direction shake of the video camera, and the image shake in the Y direction is corrected.

Here, the operation of the correction angle limiting unit 54 will be specifically described with reference to FIGS. FIG.
Shows an example in which the correction angle restriction unit 54 does not limit the correction angle during intentional panning, and reference numeral 61 in FIG.
Reference numeral 62 in (b) indicates a change in the correction angle. In (b), + θ represents the upper limit of the correction angle in one direction, and −θ represents the upper limit of the correction angle in the other direction. As shown in this figure, when intentionally panning, when the correction angle is not limited by the correction angle restriction unit 54, the correction operation works as the correction angle reaches the upper limit, and after the pan is completed. Since the correction angle returns to 0 after the elapse of the predetermined time, the operator feels strange.

On the other hand, FIG. 8 shows an example in which the correction angle is limited by the correction angle limiting unit 54 during intentional panning, and reference numeral 63 in FIG. The reference numeral 64 denotes an X-direction mode switch 17
X indicates the timing at which it is turned on, and reference numeral 65 in (b) indicates a change in the correction angle. In this example, the limitation of the correction angle in the correction angle limiting unit 54 is X
It is performed for a certain period of time after the direction mode changeover switch 17X is turned on, and is performed by setting the upper limit value of the X-direction angle control signal to be smaller than normal (for example, 1/3 to 1 to 4). I have to. As shown in this figure, when the correction angle is restricted by the correction angle restriction unit 54 during intentional panning, the correction angle is restricted, so that the correction angle is not restricted. In comparison with the above, the amount of change in the correction angle until the correction angle returns to 0 after the end of the panning is small, and it is possible to prevent the operator from feeling uncomfortable.

As described above, in the image blur correction apparatus according to the present embodiment, when the operator intentionally pans, the X-axis is used to instruct the image blur correction operation in the X direction to be restricted. A direction mode changeover switch 17X and a Y direction mode changeover switch 17Y for instructing to restrict the image shake correction operation in the Y direction when the operator intentionally tilts are provided.
In accordance with the instructions by 7X and 17Y, the restriction of the image blur correction operation in the X direction and the restriction of the image blur correction operation in the Y direction are independently performed. Therefore, even if the image shake correction operation in the X direction, that is, the pan direction is restricted during intentional panning, the image shake correction operation is performed as usual in the Y direction, that is, the tilt direction. Even if the image shake correction operation in the direction, that is, the tilt direction is restricted, the image shake correction operation is performed as usual in the X direction, that is, in the pan direction. Therefore, according to the image shake correction apparatus according to the present embodiment, even during intentional panning or tilting, image shake can be corrected without giving an uncomfortable feeling to the operator.

It should be noted that the present invention is not limited to the above embodiment. For example, in the above embodiment, an intentional fast pan / tilt is detected, and when an intentional fast pan is detected, X is detected. The image shake correction operation in the X direction is limited by the correction angle restriction unit 54 in the direction angle signal generation unit 42X, and when an intentional fast tilt is detected, the correction angle restriction unit in the Y direction angle signal generation unit 42Y controls the image shake correction operation. Means for restricting the image blur correction operation in the Y direction may be used together. The HPF at the time of intentionally fast pan / tilt
Since the level of the output signal is larger than the level of the output signal of the HPF at the time of camera shake, intentionally fast pan / tilt can be detected based on the frequency and level of the output signal of the HPF. is there.

Further, in the above embodiment, the switches 17X and 17Y for instructing the restriction of the image blur correction operation independently in the X direction and the Y direction are provided, but the switches 17X and 17Y are further provided in both the X direction and the Y direction. A switch may be provided for instructing restriction of the shake correction operation, and when the switch is turned on, the image shake correction operation may be limited in both the X direction and the Y direction.

A switch 17 is used as an instruction means.
The lever is not limited to X and 17Y, but may be, for example, one lever that can be tilted in two orthogonal directions and two sets of contacts for independently detecting the movement of the lever in each direction. It may be an integral type, such as a switch provided.

As a mechanism for correcting image blur,
The correction optical system capable of bending the optical axis by moving the lens in a direction orthogonal to the optical axis is not limited to the one using a prism with a variable apex angle as in the prism block 13 described in the embodiment. Etc. may be used. Also,
The shake detecting means is not limited to the one using the angular velocity sensor, but may be one using an acceleration sensor or the like.

The image blur correction device of the present invention may be integrated into a video camera or the like, or may be an adapter type that is detachably attached to the video camera or the like. In addition, the present invention is not limited to a video camera, and can be applied to other types of imaging devices such as a still camera and a camera using a movie film.

[0034]

As described above, according to the image blur correction apparatus of the present invention, there is provided the instruction means for instructing that the correction of the image blur by the correction means is independently restricted in the vertical and horizontal directions. In response to the instruction from the instruction means, the correction by the correction means is limited independently in the vertical and horizontal directions by the correction restricting means, so that the operator does not feel uncomfortable even during intentional panning or tilting. Therefore, it is possible to appropriately correct the image blur.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a servo circuit in an image shake correction apparatus according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram illustrating a schematic configuration of a video camera including an image shake correction device according to an embodiment of the present invention.

FIG. 3 is an explanatory diagram showing a state where the video camera shown in FIG. 2 is viewed from a side.

FIG. 4 is a perspective view showing a configuration of a prism block in FIG. 2;

FIG. 5 is a block diagram illustrating a schematic configuration of a servo system of the image shake correction apparatus according to the embodiment of the present invention.

FIG. 6 is a flowchart showing the operation of the CPU in FIG. 1;

FIG. 7 is an explanatory diagram for describing an operation of a correction angle limiting unit in FIG. 1;

FIG. 8 is an explanatory diagram for describing an operation of a correction angle limiting unit in FIG. 1;

[Explanation of symbols]

13 ... Prism block, 15 ... X direction gyro sensor, 16 ... Y direction gyro sensor, 17X ... X direction mode switch, 17Y ... Y direction mode switch,
26: X direction correction motor, 27: Y direction correction motor, 31, 33: glass plate angle sensor, 32, 34: servo circuit, 42X: X direction angle signal generator, 42Y: Y
Direction angle signal generation unit, 43X... X direction drive control unit, 43
Y: Y direction drive control unit, 45: CPU, 53: X direction mode switching detection unit, 54: correction angle limit unit

Claims (1)

[Claims] 1. A shake detecting means for detecting a shake which causes an image shake in both a vertical direction and a horizontal direction, and an image shake in both a vertical direction and a horizontal direction based on a detection output of the shake detect means. Correction means capable of performing correction; instruction means for instructing that the correction by the correction means be independently limited in the up-down direction and the left-right direction; An image shake correction apparatus, comprising: a correction limiting unit that independently limits a direction and a left-right direction.