Patent ID: 8427570
Filing Date: 2013-04-23
Classification: G02B,G03B

Abstract:
1. A focus position control apparatus comprising: a photographing optical system for forming a subject image using light from a subject; an imaging unit for generating at least first and second image signals by performing photoelectric conversion on the subject image formed by the photographing optical system on an imaging plane with lights having at least two different wavelengths or wavelength bands; a focus-position movement mechanism for moving the photographing optical system in a direction along an optical axis relative to the imaging plane of the imaging unit; a focusing state evaluator for evaluating a focusing state in each wavelength or wavelength band based on the at least first and second image signals generated by the imaging unit; and a movement controller for driving the focus-position movement mechanism based on an evaluation result from the focusing state evaluator, wherein the focusing state evaluator includes a data storage for storing data of a defocus property of the photographing optical system in the at least two different wavelengths or wavelength bands, and the focusing state evaluator evaluates the focusing state from the first and second image signals based on the data of the defocus property stored in the data storage.