Patent ID: 6827266
Filing Date: 2004-12-07
Classification: G06K

Abstract:
A bar code scanner for use in a point of sale system including a terminal, the bar code scanner comprising:a scan window; a laser source for producing a scan beam emerging from the scan window and striking an object within range of the scan window to produce reflections from the scan beam off of the object, a portion of the reflections comprising light reentering the scan window; collection optics for collecting the light reentering the scan window; a photodetector for producing a scanner signal based on the light collected by the collection optics; a time-space module for processing the scanner signal to estimate imaging information relating to the object producing the reflections, including a decoding enhancement function for computing beam position and beam length information for a scan beam striking a bar code; a bar code module for processing the scanner signal to obtain bar code information, wherein the bar code module employs the beam position and beam length information to improve decoding accuracy; and a processor for controlling transfer of the bar code information to the terminal, the processor executing a scanning enhancement function for receiving the imaging information and the bar code information and comparing expected object information associated with the bar code information and actual object information given by the imaging information to evaluate whether or not a valid scan occurred, the scanning enhancement function being operative to transfer the bar code information to the terminal if a valid scan occurred, the scanning enhancement function being operative to prepare an error message for display by the terminal if an invalid scan occurred.