Patent ID: 7231143

Claim:
An autofocus camera comprising: a taking lens system, including a focusing lens movable on a lens optical axis, for being set in an in-focus position according to an object distance, to condense object light from a photographic object on a focal plane; a lens driving mechanism for moving said focusing lens on said lens optical axis; a pickup element, disposed on said focal plane, for outputting pickup data by picking up said object; an aperture stop unit for limiting a light amount of said object light; an aperture stop shifting mechanism for moving said aperture stop unit alternately in a first direction and a second direction reverse thereto on a plane perpendicular to said lens optical axis, to set said aperture stop unit cyclically between first and second light amount gravity centers, wherein said first and second light amount gravity centers are equidistant from said lens optical axis, and wherein said pickup element outputs first and second sample pickup data by picking up said object through said aperture stop unit when said aperture stop unit is set at respectively said first and second light amount gravity centers; a first determiner for determining first image deviation information by comparison between said first and second sample pickup data; a second determiner for determining second image deviation information by comparison between a preceding output of said first sample pickup data and a present output of said first sample pickup data; and a controller for checking focusing of said focusing lens according to said first and second image deviation information, and for actuating said lens driving mechanism to set said focusing lens in said in-focus positions, wherein said aperture stop shifting mechanism has actuators for moving said aperture stop unit and said actuators change an opening size of said aperture stop unit by setting said aperture stop unit on said lens optical axis, to adjust said light amount for an exposure.