(under subclass 242) Subject matter in which the exposure control circuit drives a stepping motor for controlling the amount of light reaching the film.
(1) Note. A stepping motor is an electromechanical device which rotates by a fixed amount each time it is pulsed.
SEE OR SEARCH THIS CLASS, SUBCLASS:
256, for shutter speed function controlled by stepping motor.
260, for diaphragm function controlled by stepping motor.
SEE OR SEARCH CLASS
310, Electrical Generator or Motor Structure, 49, for structure of stepping motor.
318, Electricity: Motive Power Systems,
685, for stepping motors in a closed-loop servo environment, in general.
