Raster distortion correction circuit
US5115171A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 28, 1991 |
| Grant date | May 19, 1992 |
| Priority date | — |
| Expiry date | Jun 28, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G1/04
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An East-West switching transistor is coupled between a flyback transformer primary winding and a horizontal deflection output transistor circuit to control retrace energy to obtain an East-West modulation of the deflection current amplitude as required for East-West pincushion raster correction. The East-West switching transistor isolates a retrace resonant circuit that includes a horizontal deflection winding from a flyback resonant circuit that includes the flyback transformer during a portion of retrace. The deflection winding is coupled to a common conductor to permit the use of a retrace voltage sample developed in the deflection winding as a feedback signal to synchronize the deflection current to the video signal. The arrangement reduces phase modulation of the deflection current as a function of beam current variations, that could be visible as a beam current dependent horizontal picture shift or a raster bending in a horizontal direction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.