Optical code reader including circuitry for processing the read symbology

摘要

An amplifier has an input responsive to an optical detector. An analog-to-digital converter is responsive to an output of the amplifier. A processor activates an optical emitter, and reads a first sample from the analog-to-digital converter. Upon determining that the first sample is less than a first threshold, the processor applies a first signal to a control input of the amplifier for a first duration. The processor reads a second sample from the analog-to-digital converter. Upon determining that the second sample is greater than a second threshold, the processor applies a second signal to the control input for a second duration less than the first duration.