Laser scanning code symbol reading system employing programmable decode time-window filtering

摘要

A method and system for reading code symbols using a code symbol reading system having a programmable decode time-window filter mode of operation. During this mode of operation, only decoded code symbols that have been scanned within a selected (e.g. central) portion of the laser scan line field are processed according to a special decode time-window filtering function. In particular, if the decoded bar code symbol is a programming-type bar code symbol, then the system controller applies the function represented by the programming-type bar code symbol; and if the decoded bar code symbol is a non-programming-type bar code symbol, then the system controller either transmits symbol character data associated therewith to the host system or stores the symbol character data within memory aboard the bar code symbol reading system.

主权项

1. A system for reading code symbols in a scanning field, comprising:
a housing having a switch for generating an activation signal when pressed; a range detection subsystem for determining a distance between the system and a code symbol in the scanning field; a source for generating a light beam; a scanning mechanism for scanning the light beam across the scanning field; a photo-detector for detecting the intensity of light reflected from the scanning field and generating a signal corresponding to the detected light intensity; and a processor for processing the signal and, in response to the activation signal generated by the switch, implementing a time window filter mode of operation in which the processor is configured for: determining if a portion of a signal corresponding to a code symbol is within a decode time window; and only decoding the code symbol if a portion of the signal corresponding to the code symbol is within the decode time window; wherein the decode time window corresponds to a portion of a scan line; and wherein the processor is configured for changing the portion of the scan line to which the decode time window corresponds based on the distance determined by the range detection subsystem.