Method and a device for reducing an electric field produced by a cathode ray tube in its surroundings
US6351084B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 2, 2000 |
| Grant date | Feb 26, 2002 |
| Priority date | — |
| Expiry date | Feb 2, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2229/0015
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The invention relates to a method and a device for reducing an electric field produced by display devices equipped with cathode ray tubes, in their surroundings. According to the invention, a part of a spectrum (ff), caused by a picture content, the level of which is separately adjusted, is discriminated from an interference voltage frequency spectrum (fs), produced by the display terminal and caused by deflection signals (fv, fh). Spurious pulses, significant for the generation of the electric field, are connected to a compensation circuit, wherein they are summed and supplied to a common emitter. The directions of the pulses are determined so that the electric field produced by the emitter reverses the field produced by the display device.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.