Graphics generator
US4146925A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 4, 1977 |
| Grant date | Mar 27, 1979 |
| Priority date | — |
| Expiry date | Aug 4, 1997 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G1/10
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A graphics generator responds to signals defining a pattern to be displayed. The pattern comprises a plurality of pattern segments each of which may be a vector, conic or alpha numeric character. The graphics generator produces digital signals which are capable of driving a display through an A/D converter to produce a visual representation of the desired pattern segment. The pattern segment is broken up into a plurality of strokes of constant length regardless of orientation. Chaining the strokes on the display thus produces the desired pattern. An input signal defining a vector defines both the length and the orientation of the vector and these quantities are stored in length and orientation registers, respectively. The orientation signal is employed as an address into a sine/cos memory to derive stroke components in an orthogonal coordinate system which are then added to a beginning position of the stroke to produce the stroke end point. At the same time, a counter containing a quantity representative of the length of the desired vector is decremented. Repeating this process produces a series of digital signals representing strokes of constant length which can drive a display to…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.