Cathode-ray tube with improved electron gun
US5325013A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 1, 1992 |
| Grant date | Jun 28, 1994 |
| Priority date | — |
| Expiry date | Sep 1, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J29/503
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An improved cathode-ray tube includes a viewing screen and an electron gun for generating and directing three electron beams toward the screen. The gun includes at least eight electrodes spaced in order from three cathodes, with the furthest electrode from the cathodes being interconnected to a tube anode. The electrodes form a beam forming region, a first quadrupole lens, a main focus lens and a second quadrupole lens in the path of each electron beam. In the improvement, the second quadrupole lens is positioned on the anode side of main focus lens, with the first quadrupole lens being diverging for defocusing the beams, and the second quadrupole lens being converging for focusing the beams in the horizontal plane.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.