Apparatus for suppressing field radiation from display device
US5260626A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 19, 1992 |
| Grant date | Nov 9, 1993 |
| Priority date | — |
| Expiry date | Feb 19, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2229/0053
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In order to eliminate any harmful influence due to electric field radiation on the human body, electric field radiation from a front surface of a cathode ray tube is reduced. A degaussing coil arranged in proximity to a peripheral edge of a front surface of a cathode ray tube is employed advantageously. The degaussing coil is supplied with a voltage which is opposite in polarity to an electric field radiated from the front surface of the cathode ray tube. The reverse polarity voltage is derived from an output signal obtained from an output signal of a horizontal deflection circuit by a flyback transformer and/or derived from a voltage obtained by phase-inverting an anode voltage fluctuating in vertical synchronization. After a degaussing operation is completed, relay contacts are opened on the basis of a timer-controlled relay switch, thereby completely cutting the connection between the degaussing coil and a degaussing power source generating an alternating current which is supplied to the degaussing coil for the degaussing operation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.