Perforated card reading system for record keeping - uses fibre=optic sensors to create binary signals using phototransistors

摘要

The need for sensitive and fragile scanning equipment is eliminated in a rapid card reading device. A matrix of 49 fibre optic terminations (12) is positioned adjacent to the punched card (7) in order to selectively collect light transmitted from an illuminated scattering plate (5) through the holes. Photo-transistors at the end of each fibre optic cable convert the presence or absence of light into TTL compatible binary data which may be stored in an electronic memory. Information coded in the pattern of perforations can thus be obtained almost immediately. The card housing (9) ensures that the card is automatically correctly positioned with little freedom of movement. Control perforations can be used as a trigger for the light source when a card is introduced.