The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 25, 2003
Filed:
Aug. 13, 2002
William Martin Belknap, Lawrenceville, GA (US);
John Baird Keys, Duluth, GA (US);
NCR Corporation, Dayton, OH (US);
Abstract
Techniques for determining a position for a rotating optical element, or spinner, of a bar code scanner are described. A diffractive element is positioned so as to be struck by a laser beam produced by a laser source and reflected from the spinner when the spinner is in a reference position. The diffractive element diffracts the reflected beam to produce a diffracted line which strikes a reference position photodetector, thereby causing the reference position photodetector to produce a reference position photosignal. The reference position photosignal can be read by a controller to determine when the spinner is in the reference position, and the position of a Hall sensor can be read at the same time in order to calibrate the reading of the Hall sensor with the reference position. Thereafter, the reading of the Hall sensor can be used to provide accurate position information for the sensor and the position information can be used to control activation and deactivation of the laser source when the spinner is in appropriate positions to produce a desired scan pattern.