APPARATUS AND METHOD FOR AUTO-FOCUSING IN A VIDEO CAMERA

摘要

a light emitting element (10) providing a light beam for distance measuring, on actuation by a driver (100); a photosensitive element (20) having two channels, in which photocurrent signals are generated in dependence on the position of an impingement point of light from the element; two voltage-current converters (30,40) processing the photocurrent signals of each channel; a time division selector (50) processing the output signals of the two converters; a filter (60) through which the selected output signal is passed; an integrator (70) amplifying the output signal of the filter; a comparator (80) outputing a level signal according to the compared value by comparing output signal of the integrator (70) with the set voltage signal; and a microcomputer(90) controlling the focussing controlling motor having its owm driver (110).