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:
May. 25, 1993
Filed:
Apr. 09, 1992
Michel J Denber, Rochester, NY (US);
Xerox Corporation, Stamford, CT (US);
Abstract
A method and apparatus are provided for detecting the presence of dirt or abrasions or etched areas on a document platen and for preventing these defects from being reproduced as unwanted spots on output copies. The platen is first scanned without a document placed thereon and an electronic image is generated and stored which contains information on the location of a dirt spot or inherent defects such as etched marks. Upon the initiation of a scanning mode with a document placed on the platen, the scanned electronic document image is subjected to a logical XOR process to correlate the previously stored spot location with the same location on the document image which is generated and stored. Once the spot location is determined, the spot is erased. A further logical step is used to determine whether the spot lies wholly or partially within any informational areas of the document image. To the extent there is such an overlap, the spot is restored to black in the overlapping areas.