Abstract

Light flux passing through two superimposed transmitting screens on which bars and spaces are encoded is sensitive to their lateral displacement. This property of bar code systems provides the possibility of fixing an absolute reference mark in the measuring operations of optoelectronic transducers for length or angle measurements. Attention is concentrated on the problem of how to increase the contrast of the main autocorrelation peak above the rest of the correlation signal.

© 1987 Optical Society of America