Convergence correction circuit for cathode ray tube
US5396156A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 24, 1993 |
| Grant date | Mar 7, 1995 |
| Priority date | — |
| Expiry date | Sep 24, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J29/51
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A dynamic convergence apparatus of a simplified arrangement can reduce a distortion of a beam spot on a periphery of a picture screen and improve a focusing, wherein a parallel circuit of a high resistance value resistor (R) and a diode (D) is connected between low voltage side electrode plates (3), (4) and high voltage side electrode plates (1), (2) to which an anode voltage (HV) is applied, a capacitor (C) is formed by coating a conductive layer on the inside and outside of a tube envelope of a color CRT while glass of the tube envelope is used as a dielectric material, and a convergence voltage which results from adding a vertical parabolic wave voltage to the horizontal blanking period of a modulated voltage provided by amplitude-modulating a DC voltage very slightly lower than the anode voltage (HV) by horizontal and vertical parabolic waves is commonly supplied from one end side (outside of the tube envelope) of the capacitor (C) to the low voltage side electrode plates (3), (4).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.