Patrick John Zijlstra

Performance of barcode scanner using peak detection with interference from LED lamps

This paper presents a new model for barcode scanners that suffer from the interference of LED lamps, to quantify the system performance in terms of Timing Signal-to-Interference Ratio (TSIR), particularly as a function of modulation depth and frequency of the flicker in the LED lighting. Physical characteristics for laser scanner channels are presented, including laser beam path and LED interference path. The barcode and LED interference are described in detail based on the scanning process. For the commonly used peak detection algorithm in the scanner, we derive expressions for the TSIR and we present numerical results for a typical system.