| 摘要 |
PURPOSE:To prevent the input of abnormal information and to read only accurate information surely, by controlling the processing of the read signal in accordance with the output of the distance detecting circuit, in the information reader where information is read optically by the portable reader. CONSTITUTION:The output of portable reader 1 is led to distance detecting circuit 8 through cable 6 to detect distance (l) between the surface of recording medium P and the tip part of reader 1. If this distance (l) is shorter than the set value, the output of distance detecting circuit 8 becomes signal ''1'', and output signal A of amplifier 7 is transmitted to quantizing circuit 15, and a prescribed signal processing is performed. Meanwhile, if distance (l) is longer than the set value and the output of distance detecting circuit 8 is signal ''0'', output signal A of amplifier 7 is held in the emitter potential of transistor 14 and is not transmitted. Consequently, the erroneous read due to lenthening of distance (l) is prevented. |
