| 摘要 |
PURPOSE:To obtain a range finder for auto-focusing apparatus which can highly accurately and quickly measure a distance to an object while priority is given to ranging of a short distance so that focusing can be securely done even if a plurality of objects exist. CONSTITUTION:An object is captured by a light receiving sensor comprising three line sensors, a zero-cross point of secondary difference of its brightness distribution is calculated and detected, and a coincidental point of three zero- cross behaviors as regards the three line sensors is detected while one of the three line sensors is made to be a reference and the other two are appropriately shifted. At the time of detecting the coincidental point, a predetermined one of a plurality of ranging regions comprising a plurality of pixels of the line sensor so as to measure a distance to the object from a shift amount of the selected data. |
