Focus detecting apparatus

An apparatus for measuring the distance between an object and the apparatus, comprising:

• (1) scanning means for scanning the entire distance range to be measured said scanning means detecting objects within said range but at different distances from the apparatus and for producing an output corresponding thereto in a time series;
• (2) means for producing a distance signal representing the scanned distance in a time series in synchronism with the scanning of said scanning means;
• (3) distance selecting means extraneously operable to select a desired distance range within the entire distance range to be measured;
• (4) means for extracting the output of said scanning means within said selected distance range in accordance with the output of said distance signal producing means corresponding to the distance range selected by said selecting means;
• and
• (5) means for providing an output representing the distance between an object within said selected distance range and the apparatus from the output of said extracting means.

An automatic focusing apparatus comprising:

• (1) an image forming lens system for forming the image of an object on a predetermined surface;
• (2) distance selecting means extraneously operable to select a desired distance range within the focusable distance range of said image forming lens system;
• (3) range finding means for measuring the distance between an object within the selected distance range and the automatic focusing apparatus in accordance with the output of said distance selecting means;
• and
• (4) means connected to said range finding means for focusing said image forming lens system to an object within the selected distance range in accordance with the output of said range finding means.