vidicon à émission secondaire

OBS: During writing, the pattern of photoelectrons generated at the photocathode by the input light is imaged onto the target as a halftone potential pattern generated by secondary electrons. Scanning of the target surface by the reading beam may be accomplished either during writing or as a later step. As in other vidicon tubes, capacitive discharge of the target to cathode potential in reading automatically erases the target and leaves it prepared for a new image.