Binary device for bar code reader

摘要

A binary device suitable for a bar code reader performs a binary signal conversion, without depending on a laser beam scanning rate. The binary device includes differentiating circuitry for differentiating an analog signal including a binary code signal, peak point detecting circuitry for detecting the positive and negative peak points of a differential signal from the differentiating circuitry, first gate signal outputting circuitry for outputting a first gate signal when the differential signal is more than a first preset level, second gate signal outputting circuitry for outputting a second gate signal when the differential signal is less than a second preset level, positive peak point detection sequential circuitry for detecting a positive peak point from the peak point detecting circuitry when a signal variation in the first gate signal is detected, and negative peak point detection sequential circuitry for detecting a negative peak point from the peak point detecting circuitry after a change in the second gate signal is detected.