Method and apparatus for displaying multiple images in overlapping windows
US4710767A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 19, 1985 |
| Grant date | Dec 1, 1987 |
| Priority date | — |
| Expiry date | Jul 19, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G5/14
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A circuit is provided which receives pixel data and pixel addresses from a graphics processor and effectuates rapid clipping of image information lying outside of a corresponding window, and also provides a template memory for storing information corresponding to all areas of that window which are obscured by a higher priority window. The pixel addresses are simultaneously applied to an image memory, the template memory, and the window clipping circuit. A write control circuit enables a write signal produced by the graphics processor to be applied to a write input of the image memory only if the present pixel is located within the present window, as determined by the window clipping circuit, and is not in an obscured area of that window, as determined by the read-out of the template memory.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.