Graphics display terminal and method of storing alphanumeric data therein
US4757309A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 24, 1985 |
| Grant date | Jul 12, 1988 |
| Priority date | — |
| Expiry date | Jun 24, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G5/06
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The specification describes a method of storing alphanumeric characters in a graphics display terminal comprising a raster-scan display device and a refresh buffer including a plurality of bit planes each having a respective bit storage location corresponding to each addressable pel position on the screen of the display device. In the method, a first bit plane stores high resolution luminance data defining alphanumeric characters each as a selection of "on" bits within a respective n.times.m array where n is the width of the character box in the scan line direction, and at least one further bit plane stores low resolution color data for the characters. The attribute plane comprises a respective n-bit set of storage locations which corresponds to each n-bit wide by one pel deep portion of a character box in the luminance plane and defines at least the color and/or intensity of the foreground and background of the character for the width of the character box in respect of a single scan line. The specification also describes a graphics display terminal in which data in the luminance and attribute planes may be selectively decoded either as alphanumeric data stored as above, or as bit-…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.