Image rotate control circuitry
US4467448A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 4, 1981 |
| Grant date | Aug 21, 1984 |
| Priority date | — |
| Expiry date | Dec 4, 2001 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K2215/0091
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Image rotate control circuitry buffers one column of display or video data which is subsequently printed along a horizontal print line. A video dot counter cycles each horizontal scan line while a print line counter cycles each vertical scan. Video data is entered into the buffer when the count in the video dot counter equals the count in the print line counter. After one refresh of the display the buffer contains one print line of data. This data is shifted from the buffer to the printer during the vertical retrace or vertical blank period of the display. The control circuitry sends a strobe signal to the printer for the print operation as a new column of data is being buffered during the next refresh of the display.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.