Raster distortion correction circuit
US5399945A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 3, 1993 |
| Grant date | Mar 21, 1995 |
| Priority date | — |
| Expiry date | Jun 3, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N3/233
- 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 and coupled to the East-West switching transistor, to control the switching operation in a manner that bypasses the flyback transformer. A resistor coupled in series with the primary winding develops a voltage, during trace, that is indicative of beam current. The resistor voltage is coupled to the East-West switching transistor to prevent beam current variation from causing raster width variation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.