Asymmetric space-saving cathode ray tube with magnetically deflected electron beam
US6674230B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 13, 2000 |
| Grant date | Jan 6, 2004 |
| Priority date | — |
| Expiry date | Jul 17, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2229/88
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A cathode ray tube includes an electron gun directing electrons away from a faceplate having an electrode biased at screen potential. One or more electromagnets located on or near the rear wall of the tube envelope are biased with dc currents so that the electron beam (three beams in a color tube) is deflected by the magnetic field produced thereby to impinge upon the faceplate. The electron beam is magnetically deflected over a relatively small angle as it exits the electron gun to scan across the faceplate to impinge upon phosphors thereon to produce light depicting an image or information. The electromagnet closest the electron gun is typically biased to produce a strong magnetic field to deflect electrons to the faceplate near to the electron gun. The electromagnets more distant the electron gun produce magnetic fields to direct electrons towards the faceplate, with the electromagnet most distant the electron gun deflecting the electrons to tend to increase the landing angle thereof on the faceplate. One or more of the foregoing electromagnets may be utilized in cooperation with one or more electrodes biased at a potential to similarly deflect the electrons to the faceplate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.