Method and device for checking punchcards

摘要

The punch (20) controlled by a computer (10) makes holes (2) in a punchcard (1) in accordance with the programmed commands of the computer. The holes (2) are scanned by the check reader (30) and are again compared with the program in the computer. In the case of differences, the punch (20) is stopped. The punchcard (1) passes between a transmitter part and a receiver part. In the transmitter part, a transmitter (5) in the form of a light-emitting diode is provided for each channel of the punchcard and in the receiving part one receiver (6) each is provided in the form of a phototransistor equally and opposite. One channel after the other is scanned and evaluated consecutively switched in time. The information of the perforation is forwarded for comparison to the computer (10). <IMAGE>