Method and apparatus for reading characters

Abstract

Abstract 916,305. Automatic character reading. OLIVETTI & C. S.p.A., ING. C. June 26, 1961 [July 1, 1960], No. 22965/61. Class 106 (1). Magnetic characters formed by seven vertical lines, Fig. 2, are sensed to derive a series of pulses the six intervals between which are of long or short duration and after amplification and re-shaping in units 2 and 4 are applied to a multivibrator 6 which in effect subtracts a fixed period from the interval signals producing pulses of corresponding duration which are each integrated in a condenser 10 until the next pulse arrives and the output applied to a threshold device 12. The long pulses will reach values in excess of the threshold value to produce a " 1." Otherwise a " 0 " is produced. These pulses are applied in common to gates 33-38. The pulses derived from the senser on emerging at 7 from multivibrator 6 are also applied to a counter 22. The outputs from the three stages are gated together in gates 26-32 to give successive timing pulses on seven leads P1-P7. The first six enter the successive binary bits into six storage stages 14-19 and the seventh which resets the store over line 39, and closes a gate 8, corresponds to the zero condition of the counter 22. The pulses at 7 pass through the gate 8 during sensing to the integrating capacitor 10. The counter is reset by a signal on lead 46 which is derived from a threshold device 45. Successive pulses from the senser are differentiated at 40 and used to make transistor 41 conduct so as to charge condenser 42. This discharges through resistor 43 at a steady rate, such that during the scanning of a character the voltage never drops below the threshold level of device 45. At the end of the character the condenser discharges and the threshold device gives a resetting signal. The circuit 47 prevents the counter starting on a spurious mark preceding a character as the interval will usually be large enough to allow condenser to discharge to the threshold level and reset the circuit.

Inventors

No inventors recorded.

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