Variable horizontal deflection circuit capable of providing east-west pincushion correction
US4429257A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 29, 1982 |
| Grant date | Jan 31, 1984 |
| Priority date | — |
| Expiry date | Sep 29, 2002 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N3/233
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A controllable switch operated at the horizontal deflection rate is coupled to a horizontal deflection winding to generate scanning current during a trace interval of a deflection cycle. A deflection retrace capacitor forms a retrace resonant circuit with the deflection winding during the retrace interval. A supply inductance such as a winding of a horizontal output transformer is coupled either conductively or magnetically to a source of supply energy. A second capacitor is coupled to the supply inductance and to the controllable switch and forms a second resonant circuit with the supply inductance within the retrace interval to generate a pulse voltage. The pulse voltage energizes a load circuit such as the ultor high voltage circuit. A modulation inductance is coupled to a source of modulation signals and to the deflection winding and supplies a modulation current to the retrace resonant circuit to modulate the amplitude of the scanning current without modulating the amplitude of the supply inductance pulse voltage. The modulation may occur at a vertical rate to provide east-west pincushion distortion correction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.