Display system comprising a windowing mechanism
US5091720A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 30, 1989 |
| Grant date | Feb 25, 1992 |
| Priority date | — |
| Expiry date | Jan 30, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G5/06
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In a display system having a palette for chrominance and/or luminance information, a display buffer for information defining the pixels of a display field, including index values for indexing the palette select the chrominance and/or luminance of the pixels, a windowing mechanism is provided for associating a different range of index values with each of a plurality of windows and for responding to index values stored at individual pixel positions in the display buffer to determine the visible extent of a given window within the display field. This allows a plurality of windows to be displayed with a minimum of extra logic and without unduly constraining the choice of colors available within those windows. In the described embodiment, windows are defined in a first phase by storing index values from the range of values associated with that window at all pixel positions for that window. Then, in a second phase, the output of a range comparator for comparing index values stored in the display buffer to the range of values associated with a given window is used to control multiplexer means to cause an item of update information destined for a particular pixel position to be stored at t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.