ELECTRONIC CONTROLLER OF EXPOSURE TIME OF PHOTOSENSITIVE MATERIALS

摘要

This invention relates to a control apparatus for regulating the exposure time of a photosensitive material comprising a first photoelectrical transducer means adapted to be exposed to light from a source adapted to illuminate the photosensitive material and operative to produce an electrical output signal corresponding to the intensity of the light from the light source, electric motor means adapted to be driven in accordance with the value of said output signal, mechanical means for the division of a light beam into light pulses, said mechanical means being adapted to be driven by said motor means, a second photoelectrical transducer means adapted to receive the light pulses from said mechanical means, and counter means for comparing the number of output pulses derived from said second photoelectrical transducer means with a predetermined number of pulses representing a desired exposure time.