Patent ID: 6064432
Filing Date: 2000-05-16
Classification: G03B,H04N

Abstract:
A light quantity control device comprising:a) a motor having a driving coil and a rotor;b) a light quantity control member arranged to be moved by said motor serving as a drive source;c) speed detecting means arranged to form speed information by using information on a change of the position of said light quantity control member;d) a first circuit arranged to generate a first control voltage for controlling said motor by taking said speed information into consideration, said first control voltage varying according to brightness of an object; ande) a second circuit arranged to invert said first control voltage and to generate a second control voltage for controlling said motor, the second control voltage being opposite in polarity to the first control voltage and having approximately the same absolute value as the first control voltage, wherein said first control voltage is applied directly to one end of said driving coil while said second control voltage is applied directly to the other end of said driving coil thereby driving said motor.