BAR CODE SYMBOL SCANNING SYSTEM FOR AUTOMATICALLY LASER SCANNING BAR CODE SYMBOLS WITHIN A 3-D SCANNING VOLUME AND PRODUCING INFORMATION SPECIFYING THE POSITION OF EACH BAR CODE SYMBOL DETECTED WITHIN SAID 3-D SCANNING VOLUME

摘要

A bar code symbol scanning system for laser scanning bar code symbols within a 3-D scanning volume and automatically producing bar code symbol position information specifying the position of each bar code symbol detected within said 3-D scanning volume. The system comprises a laser scanning mechanism and a scan data signal processor. The laser scanning mechanism generates and scans a laser beam so as produce a laser scanning pattern which is substantially confined within a 3-D scanning volume having a plurality of focal planes. During system operation, the laser scanning pattern, consisting of a plurality of scanlines disposed within each focal plane, scans the bar code symbol on each object transported through the 3-D scanning volume. In response thereto, the laser scanning mechanism automatically produces scan data indicative of the scanned bar code symbol. Therewhile, the scan data processor processes the produced scan data so as to detect each scanned bar code symbol within the 3-D scanning volume, and produce bar code symbol position data specifying the position of the detected bar code symbol therewithin. By virtue of the present invention, information specifying the position of detected bar code symbols can now be accurately generated on a real-time basis, and used for various purposes including focusing a laser scanning beam to a particular focal plane within the 3-D scanning volume, steering a laser scanning beam to a particular location therein, as well as other control functions known in the bar code symbol reading art.