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:
Mar. 23, 2004
Filed:
Jun. 26, 2001
Paul K. Mazaika, Palo Alto, CA (US);
Xerox Corporation, Saitama, CT (US);
Abstract
The present invention provides a system and method for encoding digital data in a hardcopy rendering of an invisible image of circularly asymmetric dot patterns. The dot patterns are slash-like markings or glyphs tilted to the right and left with respect to the longitudinal axis of the recording medium. The glyphs are written onto a spatially periodic, two dimensional array of cell blocks to encode information without modulating the average reflectances of the cell blocks. In operation the dot patterns are written onto the recording medium in yellow at approximately a 2% pixel density to produce an image that is invisible to the naked eye, but capable of being reliably decoded by conventional machinery.