EDGE EFFECT COMPENSATING BAR CODE READER

摘要

Apparatus and method for reading a luminescent bar code (1) on a background surface (2) whose reflectance may vary over the coded area, including a scanning light (3), which excites luminescence in the bar code or reflects from the background surface of the coded area. Signals (10, 11) output by light detectors for the luminescent and reflected non-luminescent light are processed to compensate for background reflectance and bar code edge distortion using calibration parameters stored in a memory.