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. 09, 1988
Filed:
Jun. 30, 1986
Ronald W Froelich, Covina, CA (US);
Xerox Corporation, Stamford, CT (US);
Abstract
This color copying system scans the original with a raster input scanner to generate digital signals representing red, green and blue, and prints at a raster output scanner which uses cyan, magenta, yellow and black ink. In addition, under color removal is used, that being defined as the removal of a certain amount of ink from all three colors, and the addition of an equivalent amount of black ink. The first step is to convert the input scanner colors into the color being printed during the current revolution of the printing drum. This requires the solution of three equations, each of which use three look-up RAM tables. In addition, the amount of under color removal must also be calculated before the amount of ink for the dot being printed is known. This requires an additional table look-up. Finally, for the black cycle, the amount of black ink must be calculated, requiring another table. The resultant circuit, therefore, consists of nine RAM tables for the color equations, each of which is reloaded with new values at the beginning of each color printing revolution, two black tables, and the associated circuitry to perform the associated computations and to establish the synchronization and timing to allow the system to operate at reasonable speeds.