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:
Sep. 10, 1991
Filed:
Jun. 15, 1989
Todd R Comins, North Chelmsford, MA (US);
Willem A Engelse, Townsend, MA (US);
Digital Equipment Corporation, Maynard, MA (US);
Abstract
A graphics subsystem (10) employs an image memory (12) that includes an on-screen part (44) and an off-screen part (46). The locations of the on-screen memory (44) are continually scanned to provide data to be displayed on a display device (16). The off-screen part (46) stores data that represent image segments that have been occluded by windowing. To transfer data between the on-screen part (44) and the off-screen part (46), an address generator (24) generates a sequence of two-dimensional addresses representing the two-dimensional positions of the pixels whose data are to be transferred. These addresses are converted to one-dimensional addresses by a simple circuit consisting of multiplexers (26 and 28), adders (30 and 32) and a multiplier (34).