Patent ID: 7787759
Filing Date: 2010-08-31
Classification: G03B,H04N

Abstract:
1. A camera, comprising: a contrast detector that successively detects contrast data of an object image that is formed on a light-receiving surface of an image sensor; a focus detector that successively calculates a difference value between currently detected contrast data and previously detected contrast data, determines whether the detected contrast data is lower than the previously detected contrast data, and whether the difference value decreases by a given amount more than a predetermined value to determine when the difference value becomes a value equal to or less than a positive value adjacent to zero and that detects a focused situation on the basis of the calculated difference value and the detected contrast data; and a focus adjuster that drives a photographing optical system so as to shift an image-formed surface from a given position along an optical axis, said focus detector determining whether the image-formed surface surpasses a focused-position corresponding to a position of the light-receiving surface on the basis of a decreasing amount of the difference value, said focus adjuster driving said photographing optical system so as to position the image-formed surface on the focused-position when the image-formed surface surpasses the focused-position.