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:
Apr. 16, 2013
Filed:
Aug. 24, 2004
Akihiro Fujii, Saitama, JP;
Kurato Maeno, Saitama, JP;
Akihiro Fujii, Saitama, JP;
Kurato Maeno, Saitama, JP;
Oki Data Corporation, Tokyo, JP;
Abstract
In a watermarked document printing apparatus, secret information is divided, error correction encoding is performed to each divided pieces of information, and the secret information is converted into a pattern image and embedded in paper. In a watermarked document reading apparatus, after extracting signals from the pattern image on the paper, a reading error is detected by decoding the error correction code for each divided pieces of information, and the portion where the reading error exists is read again. The scanning process is performed again only to the portion where the decoding cannot be performed due to the temporal malfunction of the scanner or the like. Therefore, the pattern image can efficiently be obtained.