Patent ID: 6496225
Filing Date: 2002-12-17
Classification: G02B,H04N

Abstract:
An auto focusing device in which a first image is entered onto a sensor through a first area of an imaging optical system so as to provide a first image signal corresponding thereto, a second image is entered onto said sensor at a timing different from a timing of entering said first image onto said sensor through a second area of said imaging optical system different from said first area so as to provide a second image signal corresponding thereto, and a phase difference between said first image signal and second image signal is detected so as to obtain information for a focusing operation, wherein said sensor consists of an area sensor including a plurality of pixel lines in which pixels are arranged in a first direction and a plurality of pixel lines in which pixels are arranged in a second direction perpendicular to said first direction, said device comprising:a detecting circuit which detects levels of coincidence of first image signals in predetermined pixel lines with respect to second image signals in said predetermined pixel lines respectively; and a determining circuit which obtains information for focusing operation based on said phase difference between said first image signal and second image signal of which a coincidence level is highest among said level of coincidences detected by said detecting circuit.