Means for combining data of different frequencies for a raster output device
US5225911A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 7, 1991 |
| Grant date | Jul 6, 1993 |
| Priority date | — |
| Expiry date | May 7, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/3872
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A circuit for enabling the raster display of text or line art in one constant color against a background of another constant color or against a continuous-tone picture, or the display of a continuous-tone picture through an arbitrary shape. The circuit has four channels, one each for constant colors, continuous-tone images, image masks, and instructions. The constant colors are stored in the first channel in the form of two 8-bit colors, one for the text or line art and one for the background. Any color pair can be read from this memory, divided into two 8-bit colors, and presented at two inputs of a final multiplexer. The second channel stores continuous tone color pictures and presents this information at a third input of the multiplexer. The third channel receives masks or outlines in the form of bitmaps and the fourth channel receives instructions which may be run-length encoded. These two channels combine their data, which is then used to control the multiplexer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.