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:
Aug. 04, 1981
Filed:
Oct. 18, 1979
John D Anthony, Jr, Wilmington, DE (US);
John J Keegan, Jr, Wilmington, DE (US);
Jerald D Lee, Mendenhall, PA (US);
E. I. Du Pont de Nemours and Company, Wilmington, DE (US);
Abstract
A circular scan reader utilizes oscillating mirrors and associated optics to generate a circular scan pattern of laser light focused to a small spot. The angle of the scan emanating from a point just inside the reader through a window forms a conical shape which permits scanning inside a yarn tube without inserting any portion of the reader into the tube. When the scan passes over a bar coded label, the changes in reflection of light between the bars and spaces are detected by a photodetector mounted on the face of the window. These fluctuations in light which correspond in width to the bar and space width are converted to an electrical signal that is amplified, and decoded. A driver circuit for the oscillating mirrors controls the scan rate and scan pattern. The scan rate is modulated to cause a variation in the sweep depth in the tube thus providing an area scan. The area scan reduces the need for accurate label placement in the tube core.