Scan velocity modulation circuit with multi-mode operation
US6493040B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | May 26, 1999 |
| Grant date | Dec 10, 2002 |
| Priority date | — |
| Expiry date | May 26, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N3/32
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A video display deflection circuit includes a source of a video signal for displaying picture information contained in the video signal in a screen of a cathode ray tube. The video signal provides selectively on-screen-display information and non-on-screen-display information. A source of a first control signal has a first value, when the video signal provides on-screen-display information and a second value, when said video signal provides non-on-screen-display information. A waveform generator is responsive to the first control signal for generating a second signal at a frequency that is related to a deflection frequency having a first waveform, when the video signal provides on-screen-display information, and a second waveform, that is different from the first waveform, when the video signal provides non-on-screen-display information. A modulator generates a modulated correction signal by modulating, in accordance with the second signal, a time-derivative signal produced from the video signal, The correction signal is coupled to a scan velocity modulation winding to produce scan velocity modulated deflection of the electron beam.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.