Method of preventing multiple reads when scanning groups of optical codes

Abstract

State-of-the-art optical scanning systems feature digital imaging of multiple symbolic labels such as optical bar codes. An imaging scanner reads a label 10 to 100 times faster than a conventional laser scanner because a group of items may be placed in the read zone simultaneously, or an item may bear multiple labels, thus allowing multiple symbolic labels to be captured in a single image. A preferred system/method is directed to a software-implemented 'multiple label double read' protection scheme for preventing duplication errors in an advanced bar code reader using multiple fixed delay timers, with each timer being somewhat analogous to existing 'single label double read' schemes. Determining the presence of duplicate data is accomplished by comparing label data or portions of label data to a set of recent buffered data representing the last N labels read and transmitted within a specified delay time.