Camera and camera system capable of changing gain value and exposure time

• US 7,414,648 B2
• Filed: 09/16/2003
• Issued: 08/19/2008
• Est. Priority Date: 09/20/2002
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Imada, Shinji
• Primary Examiner(s): Misleh; Justin P.
• Application Number:
  US10/664,505
• Publication Number:
  US 20040090532A1
• Time in Patent Office: 1,799 Days
• Field of Search: 348/229.1, 348/208.16, 348/208.12, 348/239, 348/208.4, 348/238, 348/208.2, 348/234, 348/237, 348/208.5, 348/208.7, 348/208.8, 348/208.11, 348/208.99, 348/362, 348/366
• US Class Current: 348/208.12
• CPC Class Codes: H04N 23/663 for controlling interchangeable camera parts based on electronic image sensor signals
• CPC Class Codes: H04N 23/672 based on the phase difference signals
• CPC Class Codes: H04N 23/68 for stable pick-up of the scene, e.g. compensating for camera body vibrations
• CPC Class Codes: H04N 23/6812 based on additional sensors, e.g. acceleration sensors
• CPC Class Codes: H04N 23/687 by shifting the lens or sensor position
• CPC Class Codes: H04N 23/72 Combination of two or more compensation controls

Abstract

An image-pickup apparatus which improves the S/N ratio of an image-pickup system, prevents image blur and saturation of signals from an image-pickup device, and enables taking an excellent image, is disclosed. The camera of the invention which takes images through an image-taking optical system having a shake correction unit which drives a part of an image-taking optical system to correct image blur caused by camera shake and includes an image-pickup device which photoelectrically converts an object image formed by the image-taking optical system and a control circuit which controls operations of the camera, wherein the control circuit changes the sensitivity and the exposure time of the image-pickup device whether the shake correction unit is in operation or not.

Claims

1. A camera which takes images through an image-taking optical system including a shake correction unit which drives a part of the image-taking optical system to correct image blur caused by camera shake, comprising:

an image-pickup device which converts an optical image of an object formed by the image-taking optical system into image signal;

a control circuit which controls operations of the camera; and

a gain control circuit which amplifies the image signal output from the image-pickup device based on a gain value set by the control circuit,

wherein the control circuit sets the gain value of the gain control circuit to be lower and an exposure time of the image-pickup device to be longer when the shake correction unit is in operation than when the shake correction unit is not in operation.

2. The camera according to claim 1, further comprising a photometric unit which measures a luminance of the object,

wherein when the shake correction unit is in operation and a difference between a luminance of a main object obtained from the photometric unit and a luminance of a bright region other than the main object is equal to or lower than a predetermined value, the control circuit sets the gain value of the gain control circuit to be lower and the exposure time of the image-pickup device to be longer than when the shake correction unit is not in operation.

3. The camera according to claim 2, further comprising a determination unit which determines the main object in an image-taking region.

4. A camera system, comprising:

the camera according to claim 1; and

a lens apparatus including the shake correction unit and attached to the camera.