Digital character display
US4563677A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 19, 1982 |
| Grant date | Jan 7, 1986 |
| Priority date | — |
| Expiry date | Oct 19, 2002 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G5/227
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A dual mode raster scanned character display system has a text mode of operation in which characters having a first matrix size are displayed on a CRT screen and a high resolution mode of operation in which display information is bit mapped on the CRT screen. Programmable font characters are stored in a memory and are accessed by controller characters generated in response to display requests supplied by an associated information source, such as a computer or a keyboard. Each controller character includes a special screen attribute multi-bit portion which is used to modify the font characters when coupled to a video signal generator unit to display reverse video, provide underline or strike through, specify one of two fixed intensities, suppress the character or provide a software function, such as CURSOR. In text mode, each character block has a fixed size appropriate to alphanumeric character generation, i.e. ten columns by sixteen rows; in high resolution mode of operation, each character block has a size appropriate to high resolution bit mapped graphic display, i.e. sixteen columns by sixteen rows. Both display and brightness are controlled by 3 bit digital characters supplied…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.