Microfilm reader film control - has key-pad and store to control detailed motorised X and Y axis film movement

摘要

The microfilm reader equipment has a keypad control of the film movement. The keypad supplies a 5 bit code word to the motor control circuitry so that the film can be moved back and forth in both x and y directions on the film plane. The keypad (1) sends into a coder (2) which is connected to the stores (3 to 6) which in turn feed a count comparator (7). The coder (2) also provides an initiate code to circuitry (11) which starts the processing. The signal from the count comparator (7) is output to the word store (8) so that an identified code is recognised by the address counter (9) controlling the film motor (19, 20) drive control units (21, 22). The keypad (1) also has reset (15) facility and continuous up or down stepping control (12, 13).