| 摘要 |
973,118. Sensing record cards. INTERNATIONAL BUSINESS MACHINES CORPORATION. April 4, 1962 [April 14, 1961], No. 12897/62. Heading G4M. A perforated record card is sensed columnby-column by energizing neon lamps L1-L80 in sequence, photoconductive strips PC1-PC12, one for each row of the card, providing output signals representing the recorded data and also controlling the energization of lamps L1-L80 in such a way that if any column of the card is not perforated, the next lamp in the sequence is energized after a shorter time interval than the normal decay period of strips PC1-PC12 or the normal extinction period of lamps L1-L80. Each lamp L1-L80 is provided with a lucite light guide 46 and is pulsed on by the corresponding monostable circuit D1-D80 triggered by the associated stage of a ring counter 9. A start pulse at terminal 42 pulses lamp L1, and if one or more holes are present in the first column of the card an output is obtained from OR gate 35 to trigger commutator 16 which then scans the strips PC1-PC12 to produce a differentially-timed pulse (or pulses) on lead 18. The output of OR gate 35 also inhibits gate 38 to prevent the start pulse, which has been delayed by network 32, from stepping on the ring counter 9 through OR gate 31. At the completion of a scan, commutator 16 pulses lead 17, and after a suitable delay introduced by network 34, the next lamp L2 is pulsed on. If there are no holes in a column, no output is obtained from OR gate 35, commutator 16 is not triggered and gate 38 is not inhibited, so that the pulse which initiated energization of the corresponding lamp, after passing through network 32, is recirculated and causes the next lamp to be energized. The output of strips PC1-PC12 may be taken directly from amplifiers 14, in which case commutator 16 is omitted, line 15 is connected to line 17 and delay 34 suitably adjusted to account for the decay time of the strips of the extinction time of the lamps. |
