Raster distortion corrected deflection circuit
US4906902A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 24, 1989 |
| Grant date | Mar 6, 1990 |
| Priority date | — |
| Expiry date | Feb 24, 2009 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B70/10
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A deflection switch of a horizontal deflection circuit is coupled to a retrace resonant circuit that includes a horizontal deflection winding and a first retrace capacitance. A flyback transformer primary winding is coupled at a junction terminal of the deflection switch and the retrace resonant circuit. A second winding of the transformer is coupled to an ultor voltage power supply. To provide side pincushion correction, a second switch, having a conduction time that is phase modulated during horizontal retrace at a vertical rate in parabolic manner, is coupled between ground and a terminal of the retrace resonant circuit remote from the flyback transformer primary winding. The second switch is conductive during the entire trace interval and is turned-off at a controllable instant during the first half of the retrace interval. When the second switch is nonconductive, a second retrace capacitance is interposed between the flyback transformer primary winding and the retrace resonant circuit to prevent load variation in the second winding of the flyback transformer from causing raster distortion.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.