JP2002182260A - Imaging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging device having two or more camera shake correcting functions which can reduce the power consumption and effectively correct a jitter video. SOLUTION: The imaging device which coverts a picked-up image formed on the image pickup surface of an imaging device through an optical system capable of adjusting the angle of the optical axis of incident light into a video signal and outputs it is equipped with an electronic zoom means which electronically enlarges and reduces video by varying the cutting size of the picked-up image, a shake detecting means which detects a shake of the image pickup device and outputs a shake signal, an electronic shake correcting means which controls the cutting position of the picked-up image according to the shake signal, an optical shake correcting means which controls the optical axis angle according to the shake signal, and a shake correcting operation control means which varies the operation of the electronic shake correcting means and optical shake correcting means associatively with electronic zooming.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image pickup apparatus such as a video camera having a camera shake correction function and an electronic zoom function using an image pickup device, and more particularly to an image pickup apparatus having a plurality of camera shake correction functions. .

[0002]

2. Description of the Related Art Conventionally, in an image pickup apparatus such as a video camera using an image pickup device (CCD), image fluctuation due to camera shake such as hand shake has been a problem.

There are two methods for suppressing image shake caused by camera shake, namely, electronic shake correction and optical shake correction. Japanese Patent Laid-Open No. 8-12 discloses a combined image stabilization method that combines the advantages of the electronic image stabilization and the advantages of the optical image stabilization.
No. 5917 (hereinafter referred to as Publication 1). In the combined shake correction, it is necessary to effectively correct the image shake according to the shooting situation.
The photographer selects the camera shake correction method using a switch, and operates the electronic shake correction and / or the optical shake correction to correct the image shake according to the shooting situation. I have.

[0004]

However, according to the technique described in Publication 1, regardless of the electronic zoom, both or one of the electronic shake correction and the optical shake correction is operated in accordance with only the judgment of the photographer. Therefore, there is a problem that the power consumption becomes unnecessarily large.

Here, camera shake correction proposed as a method of correcting image shake will be described with reference to FIGS. 2 and 3. FIG.

FIG. 2 shows camera shake (optical axis change of incident light).
The camera shake correction (hereinafter referred to as electronic shake correction) that can obtain a stable image by adjusting the cutout position of a captured image formed on the imaging surface of the image sensor according to is there.

FIG. 3 shows camera shake correction (hereinafter referred to as optical shake correction) in which a stable image can be obtained by adjusting the optical axis angle of incident light using a prism or the like in accordance with camera shake.
Is schematically shown.

[0008] Optical shake correction requires driving mechanical elements such as a prism, and thus has a problem in that power consumption is large as compared with electronic shake correction.

The electronic image stabilization depends on the focal length of the optical system, and requires an area (hereinafter, referred to as a margin area) for changing the cut-out position of a captured image on the imaging surface of the imaging device. In particular, when the focal length of the optical system is long, there is a problem that a camera shake having a large amplitude cannot be corrected as compared with the optical shake correction unless there is a sufficient margin area.

An object of the present invention is to reduce the power consumption and effectively correct the image fluctuation by controlling the operations of the electronic shake correction and the optical shake correction in consideration of the above points. An object of the present invention is to provide an imaging device.

[0011]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention controls an electronic shake correction and an optical shake correction according to an electronic zoom.

FIG. 4 schematically shows an electronic zoom for electronically enlarging or reducing an image by changing the size of a cut-out of a picked-up image on an image pickup surface of an image pickup device.

In the electronic zoom, since the size of the cutout of the captured image is reduced with the zoom-up, a margin area required for the electronic shake correction is inevitably expanded. Therefore, if the margin area generated by the electronic zoom can be effectively used, the camera shake having a large amplitude can be corrected by the electronic shake correction. Further, the power consumption can be reduced by reducing the load of the optical shake correction as much as the effect of the electronic shake correction is increased.

According to the present invention, there is provided an image pickup apparatus for converting a picked-up image formed on an image pickup surface of an image pickup device into a video signal and outputting the same through an optical system capable of adjusting an optical axis angle of incident light. Electronic zoom means for electronically enlarging or reducing the image by changing the size of the cutout, shake detection means for detecting a shake of the imaging device and outputting a shake signal, and Electronic shake correction means for controlling the cutout position, optical shake correction means for controlling the optical axis angle based on the shake signal, and shake correction for controlling the operations of the electronic shake correction means and the optical shake correction means An operation control unit is provided, and the operation of the electronic shake correction unit and the operation of the optical shake correction unit are changed in conjunction with the electronic zoom.

In an image pickup apparatus having both optical and electronic shake corrections, the ratio of the image shake correction between the electronic shake correction and the optical shake correction is changed according to the electronic zoom. In other words, if the electronic zoom (margin area) increases,
The image shake correction by the electronic shake correction is increased, and the image shake correction by the optical shake correction is reduced.

Thus, it is possible to effectively correct the image fluctuation while reducing the power consumption.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIG.

FIG. 1 is a block diagram showing a camera unit of a video camera for realizing the present invention. 101 is a lens, 1
02 is an image sensor, 103 is a prism (variable apex prism) that can adjust the optical axis angle of incident light, 104 is a signal processing circuit, 105 is an electronic zoom control circuit, 106 is a shake detection circuit, and 107 is a shake correction control circuit. , 108 are drive control circuits.

An optical image formed on the light receiving surface of the image sensor 102 via the prism 103 and the lens 101 is photoelectrically converted and output as an image signal 109. This imaging signal 1
09 is output as a video signal 110 via the signal processing circuit 104.

The electronic zoom control circuit 105 includes the image pickup device 1
An electronic zoom control signal 111 is output, which is capable of setting the size of the cutout of a captured image on the imaging surface 02. In addition, an electronic zoom signal 112 indicating the setting state of the electronic zoom (for example, the electronic zoom magnification, the size of the cutout of the captured image, the size of the margin area, the electronic zoom operation, or the like) is output.

A shake detection circuit 106 detects an angular velocity by an angular velocity sensor and converts the angular velocity into shake information.
Output as

The shake correction control circuit 107 outputs the shake signal 11
3 and outputs shake correction information as an electronic shake correction signal 114 and an optical shake correction signal 115. In addition, according to the electronic zoom signal 112, it is possible to change the ratio of the image shake correction between the electronic shake correction and the optical shake correction.
To increase the image shake correction by the electronic shake correction and to reduce the image shake correction by the optical shake correction,
Electronic shake correction signal 114 and optical shake correction signal 1
15 is set. Conversely, when the electronic zoom is reduced, the electronic shake correction signal 114 and the optical shake correction signal 115 are set so that the image shake correction by the electronic shake correction is reduced and the image shake correction by the optical shake correction is increased.
Set.

The signal processing circuit 104 is capable of cutting out the image pickup signal 109 at an arbitrary size and position. The signal processing circuit 104 cuts out the image pickup signal 109 according to the electronic zoom control signal 111 and the electronic shake correction signal 114, and The signal 110 is output.

The drive control circuit 108 outputs a drive control signal 116 for correcting the optical axis angle of the incident light by the prism 103 according to the optical shake correction signal 115.

As described above, the video camera shown in FIG. 1 of this embodiment controls the electronic shake correction and the optical shake correction in accordance with the electronic zoom. The image shake can be corrected in a short time.

In the above-described embodiment, the case where an angular velocity sensor is used as the shake detecting means has been described. However, the present invention is not limited to this, and when detecting using a motion vector detecting method, an accelerometer may be used. Various shake detection means can be widely applied, for example, in the case of using the detection.

Also, in the above-described embodiment, as a method of cutting out a picked-up image on the image pickup surface of the image pickup device, a case where the image signal 109 is directly cut out by the signal processing circuit 104 to output the video signal 110 has been described. The present invention is not limited to this, and the image signal 109 may be stored using a memory circuit, an arbitrary position may be cut out therefrom, and the video signal 110 may be output.

Further, in the above-described embodiment, the variable apex angle prism 1 is used as the optical system capable of adjusting the optical axis angle of the incident light.
However, the present invention is not limited to this, and an optical system that can adjust the optical axis angle of various incident lights can be widely applied, for example, when one lens in a lens group is used. .

[0029]

According to the present invention, in an image pickup apparatus having a plurality of camera shake correction functions, operations of electronic shake correction and optical shake correction are controlled in accordance with electronic zoom.
It is possible to effectively correct image fluctuation while reducing power consumption.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a camera unit of a video camera that implements the present invention.

FIG. 2 is a schematic diagram schematically illustrating electronic shake correction.

FIG. 3 is a schematic diagram schematically showing optical shake correction.

FIG. 4 is a schematic diagram schematically showing an electronic zoom.

[Explanation of symbols]

 Reference Signs List 101 lens 102 imaging device 103 prism 104 signal processing circuit 105 electronic zoom control circuit 106 shake detection circuit 107 shake correction control circuit 108 drive control circuit 109 imaging signal 110 video signal 111 electronic zoom control signal 112 electronic zoom signal 113 shake signal 114 electronic Shake correction signal 115 Optical shake correction signal 116 Drive control signal 201 Optical axis 202 Captured image cutout position 203 Margin area 401 Size of captured image cutout 402 Output video

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Claims (1)

[Claims] 1. An image pickup apparatus which converts an image formed on an image pickup surface of an image pickup device into a video signal and outputs the image signal via an optical system capable of adjusting an optical axis angle of incident light. Electronic zoom means for electronically enlarging or reducing an image by changing the size of the image, shake detection means for detecting a shake of the imaging device and outputting a shake signal, and cutting out the captured image based on the shake signal A first shake correcting unit for controlling a position, a second shake correcting unit for controlling the optical axis angle based on the shake signal, and a shake for controlling operations of the first shake correcting unit and the second shake correcting unit. An image pickup apparatus, comprising: a correction operation control unit, wherein the operations of the first shake correction unit and the second shake correction unit are changed according to electronic zoom.