METHOD FOR FORMATING A BALFTONE PLATE

摘要

A half tone plate is produced by exposing it to an exposure light beam of a smaller size than the half tone dot area. The exposure light is independently controlled to turn on or off according to a picture signal. The luminous energy of the beam is controlled by a reference value. The control of the luminous energy is performed by the sum, the difference, the product or the quotient of the two signal values.