Real-time cursor generator
US4454507A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 4, 1982 |
| Grant date | Jun 12, 1984 |
| Priority date | — |
| Expiry date | Jan 4, 2002 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G5/08
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A system for writing cursors on a raster scanned television screen that uses the microprocessor in a display controller to produce blocks of data defining the parameters of vectors that compose the cursor. The blocks are put in a first-in first-out memory during a vertical blanking inerval or during active picture time. Each block specifies where writing of a cursor segment is to start and stop on a horizontal scan line and it also specifies a repeat count that indicates the number of lines on which the segment is to be written. Each block contains a delta value to indicate how much, if any each segment is to be displaced left or right from line to line so vertical and angulated vertical vectors can be produced. The blocks are read out of the memory consecutively by a circuit that converts the segment start and stop data to pixel counts. Pixel counters determine the writing start and stop points. When the number of horizontal lines on which segments are written equals the repeat count, the next block is processed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.