FOCUS DETECTOR, FOCUSING DEVICE, IMAGING APPARATUS, AND CAMERA SYSTEM

摘要

PROBLEM TO BE SOLVED: To prevent a focus detecting accuracy from degrading, even when the output of a signal obtained for a focus detection area selected as an object of focusing from among a plurality of focus detection areas is small. SOLUTION: The focus detector includes: a first light-receiving means that receives luminous flux corresponding to a first focus detecting position set within an image plane by an optical system out of the luminous fluxes via the optical system; a second light-receiving means that receives luminous flux corresponding to a second focus detecting position within the image plane different from the first focus detecting position out of the luminous fluxes via the optical system; a focus detection means that detects the focusing state of the optical system, based on a light-receiving signal, obtained by at least either the first light receiving means or the second light-receiving means; and a control means that allows the focus detection means to detect the focusing state, based on the light-receiving signal obtained by the second light receiving means when light quantity of the luminous flux received by the first light-receiving means is smaller than light quantity of the luminous flux received by the second light-receiving means. COPYRIGHT: (C)2010,JPO&INPIT