Bar code scanner having an adaptive threshold using a first derivative amplitude

摘要

Briefly, in accordance with one or more embodiments, a scanner system may scan a target based on a first derivative of a reflectance profile received from a scanned target. Positive and negative threshold values may comprise a static portion and a dynamic portion. The static portion may comprise a constant value, and the dynamic portion may be based at lest in part on a charge profile, or a discharge profile, of a capacitor. The threshold for generating the digital signal may be set lower when the amplitude of the first derivative is lower, and higher when the amplitude of the first derivative is higher.