Microfilm recording together with production of control blips - has flash lighting source operated at high frequency to produce variable length markings

摘要

The microfilm recording process involves scanning the original item (1) line (3) as it moves at a controlled rate. The image is optically directed by mirrors (8a-8c) through an objective (9a) onto film (10) that moves at a synchronised rate. Located along side the line scanner is a mask (4) that is illuminated by a flash light source (5b). The flash frequency is selected such that a series of marks or blips are produced (12) on the film alongside each recorded frame. The control pulses operating the unit are of such a frequency that the marks are produced without gaps. USE/ADVANTAGE - Provides variable length identification markings by each frame.