Character display control circuit
US6064402A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 4, 1998 |
| Grant date | May 16, 2000 |
| Priority date | — |
| Expiry date | Sep 4, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N5/44504
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Data about display start positions are stored in an H register. An H start counter counts an original oscillation signal ORGCLK after the termination of a flyback period, and a comparator detects a start position. Flip flops and NOR gates form a clock having a cycle one and a half times as long as that of the original oscillation signal from the start position, and either the signal having a 1.5-fold cycle or the original oscillation signal is selected according to the level of a mode signal MODE. Thus, it is possible to obtain a clock OSDCLK having a frequency the same as that of the original oscillation signal up to the start position and a clock OSDCLK having a frequency corresponding to magnification from a display position. Therefore, by controlling display of characters based on the clock OSDCLK, display start positions can be made even regardless of magnification.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.