Patent ID: 7633545
Filing Date: 2009-12-15
Classification: G02B,H04N

Abstract:
1. A focus detecting system comprising: an adjustable focus taking lens; an imaging element for image production; a plurality of imaging elements for focus state detection having an optical path length difference, the plural imaging elements for focus state detection capturing a divided object light directed to the imaging element for image production by the adjustable focus taking lens; a moving unit for moving the plurality of imaging elements for focus state detection back and forth along each optical axis; a central processing unit (CPU) configured to determine a focal length of the taking lens, the CPU configured to determine an optimum optical path length difference for the imagining elements based on the determined focal length of the taking lens; an optical path length difference changing unit for changing the optical path length difference of imaging elements for focus state detection, by using the moving unit to independently and simultaneously change a position of each of the imaging elements for focus state detection to the determined optimum optical path length difference, the moving unit allowing the optical path length of each imagining element to be simultaneously increased or decreased independently of the other imagining elements; and, wherein the focus detecting system detects the focus state based on image signals from the plurality of imaging elements for focus state detection.