Patent ID: 7805067
Filing Date: 2010-09-28
Classification: G02B,H04N

Abstract:
1. A focus detection device for an image forming optical system, comprising: a micro-lens array constituted with a plurality of two-dimensionally arrayed micro-lenses; a light-receiving element array that includes a plurality of light-receiving elements receiving a light flux from the image forming optical system via the micro-lenses, the plurality of light-receiving elements being two-dimensionally disposed in correspondence to each micro-lens and outputting signals; an area setting unit that sets at least one focus detection area within a photographic image plane of the image forming optical system; an image range setting unit that sets an image range in which the focus detection area is centered; a contrast detection unit that detects a contrast of a subject image in the image range based upon the signals and outputs contrast information; a focus detection region setting unit that sets a focus detection region in the image range based upon the contrast information, the focus detection region being smaller than the image range; and a focus detection unit that detects a focus adjustment state of the image forming optical system based upon the signals, the signals being output from the light-receiving elements within the focus detection region set by the region setting unit.