Image-shake correcting device

• US 20030142218A1
• Filed: 01/22/2003
• Published: 07/31/2003
• Est. Priority Date: 01/25/2002
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Yamazaki, Tatsuya
• Granted Patent: US 6,933,968 B2
• Time in Patent Office: Days
• US Class Current: 348/208.6
• CPC Class Codes: H04N 23/68 for stable pick-up of the scene, e.g. compensating for camera body vibrations
• CPC Class Codes: H04N 23/6815 by distinguishing pan or tilt from motion
• CPC Class Codes: H04N 23/682 Vibration or motion blur correction
• CPC Class Codes: H04N 23/683 performed by a processor, e.g. controlling the readout of an image memory
• CPC Class Codes: H04N 23/687 by shifting the lens or sensor position

Abstract

There is provided an image-shake correcting device that is comprised of a detecting unit that detects shakes of the image-shake correcting device, a filter circuit that cuts off low frequency components of a detecting signal output from the detecting unit, a control circuit that controls the filter characteristic of the filter circuit such that the cutoff frequency of the filter circuit increases as the focal distance of the optical image forming unit becomes longer, and a signal processing circuit that executes signal processing for performing an image-shake correcting operation on an image signal output from the optical image forming unit, according to the detection signal having the low frequency components cut off by the filter circuit, to thereby improve the image stabilization characteristic, which is apt to be degraded on the telephoto side of the optical image forming system of the optical image forming unit.

Claims

1. An image-shake correcting device comprising:

an optical image forming unit that forms an image;

a detecting unit that detects a shake of the image-shake correcting device;

a filter circuit that cuts off low frequency components of a detection signal output from said detecting unit;

a control circuit that controls a filter characteristic of said filter circuit such that a cutoff frequency of the low frequency components cut off by said filter circuit increases as a focal distance of said optical image forming unit becomes longer; and

a signal processing circuit that carries out signal processing for performing an image-shake correcting operation on an image signal output from said optical image forming unit, according to the detection signal having the low frequency components cut off by said filter circuit.

2. An image-shake correcting device according to claim 1, comprising an image pickup element that converts an image formed by said optical image forming unit into an electrical signal, and a signal control circuit that controls the electrical signal according to the signal processing carried out by said signal processing circuit.

3. An image-shake correcting device according to claim 1, comprising an optical correcting unit that corrects an image shake, and a drive control unit controls driving of said optical image forming unit according to the signal processing carried out by said signal processing circuit.

4. An image-shake correcting device comprising:

an optical image forming unit that forms an image;

a detecting unit that detects a shake of the image-shake correcting device;

a filter circuit that cuts off low frequency components of a detection signal output from said detecting unit;

a producing circuit that produces a maximum correction angle for correcting an image shake, according to a focal distance of said optical image forming unit;

a control circuit that controls a filter characteristic of said filter circuit such that a cutoff frequency of the low frequency components cut off by said filter circuit increases as the maximum correction angle produced by said producing circuit becomes smaller while it is below a predetermined angle; and

a signal processing circuit that carries out signal processing for performing an image-shake correcting operation on an image signal output from said optical image forming unit, according to the detection signal having the low frequency components cut off by said filter circuit.

5. An image-shake correcting device according to claim 4, comprising an image pickup element that converts an image formed by said optical image forming unit into an electrical signal, and a signal control circuit that controls the electrical signal according to the signal processing carried out by said signal processing circuit.

6. An image-shake correcting device according to claim 4, comprising an optical correcting unit that corrects an image shake, and a drive control unit controls driving of said optical image forming unit according to the signal processing carried out by said signal processing circuit.