Patent ID: 6263164
Filing Date: 2001-07-17
Classification: G02B

Abstract:
A distance measuring apparatus of a camera having a variable focal length photographing lens, a Multi-AF mode and a Spot AF mode, the distance measuring apparatus comprising:a pair of image forming lenses, each image forming lens forming a subject image;a pair of line sensors on which the subject images are respectively formed through said pair of image forming lenses, each line sensor having a plurality of light receiving elements, each light receiving element converting received light into an electrical signal when actuated;a plurality of corresponding light receiving areas formed on each of said pair of line sensors, said plurality of light receiving areas comprising a center light receiving area, a left center light receiving area and a right center light receiving area, the center light receiving area being located between the left center light receiving area and the right center light receiving area at a substantial center of each of said pair of line sensors, and each of said plurality of light receiving areas further comprising a predetermined number of light receiving elements of said plurality of light receiving elements, wherein said plurality of light receiving areas respectively receive different areas of a corresponding one of the subject images formed through said pair of image forming lenses;a calculator that calculates, for each of said plurality of light receiving areas, a value corresponding to a subject distance, using said electrical signals generated through light receiving elements included in each of said plurality of light receiving areas; anda judging system that evaluates whether each of the values for said plurality of light receiving areas is reliable, said judging system evaluating the center light receiving area, the left center light receiving area and the right center light receiving area in this order, until said judging system identifies a reliable value;wherein the distance measuring apparatus adopts the first value identified as a reliable value by said judging system as an effective value in the Spot AF mode.