Code converter circuitry system for selectively rotating a video display picture
US4225929A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 29, 1978 |
| Grant date | Sep 30, 1980 |
| Priority date | — |
| Expiry date | Nov 29, 1998 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N5/2628
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A code conversion circuit especially suited for, but not limited to, use with a video display apparatus of a type in which the screen is arbitrarily divided into plural domains defined by horizontal scan lines, X.sub.i, and vertical section lines, Y.sub.j. A random access memory (RAM) used in the system stores local codes defining the video symbols to be displayed in the various domains on the screen. The code conversion circuit permits selective modification of the addresses applied to the RAM so that a picture element normally displayed in domain X.sub.i Y.sub.j can, in turn, be displayed in a domain X.sub.m Y.sub.n. Means are further provided for inverting the order in which the local codes read from the RAM are applied to the video display. Hence, the code conversion circuit is capable of rotating an image to be displayed about the center point of the display screen.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.