Color cathode ray tube apparatus having auxiliary grid electrodes
US6339284B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 26, 1999 |
| Grant date | Jan 15, 2002 |
| Priority date | — |
| Expiry date | Jul 26, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2229/5635
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
In a self-convergent type color cathode ray tube apparatus, three in-line electron beams emitted from an electron gun assembly are deflected by non-uniform magnetic fields generated by a deflection yoke and thus self-converged onto a screen. The electron gun assembly has a second grid and a third grid. First and second auxiliary grids are disposed between the second and third grids. A dynamic voltage varying in synchronism with deflection of the electron beams is applied to the first auxiliary grid situated on the second grid side. A fixed voltage is applied to the second auxiliary grid situated on the third grid side. Accordingly, the second grid, the first and second auxiliary grids and the third grid form an electron lens such that a higher astigmatism is provided by focusing in a direction perpendicular to a direction of arrangement of the three electron beams than by focusing in the direction of arrangement of the three electron beams and the degree of the astigmatism is dynamically varied. A color cathode ray tube apparatus capable of performing uniform focusing over the entire screen with a relatively low dynamic voltage is provided.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.