Electron gun for a color cathode ray tube
US5386178A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 16, 1993 |
| Grant date | Jan 31, 1995 |
| Priority date | — |
| Expiry date | Apr 16, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J29/503
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An electron gun for a color cathode ray tube includes a cathode, control and screen electrodes forming a triode, 1st to 3rd focus electrodes forming a first unipotential prefocus lens, 4th and 5th focus electrodes forming a second unipotential prefocus lens with the 3rd focus electrode, a 6th focus electrode forming a bipotential prefocus lens with the 5th electrode adjacent thereto, and an accelerating electrode for forming a bipotential main focus lens with the 6th focus electrode. Vertically-elongated electron beam passing holes are respectively formed in the outgoing planes of the 1st, 3rd and 5th electrodes and horizontally-elongated electron beam passing holes are respectively formed in the incoming planes of the 3rd, 5th and 6th focus electrodes. The 2nd and 4th focus electrodes are supplied with a predetermined first static focus voltage, the 3rd and 5th focus electrodes are supplied with a second static focus voltage higher than the first static focus voltage, and the 1st and 6th focus electrodes are supplied with a dynamic focus voltage which is synchronized with a deflection signal and whose negative peak equals the second static focus voltage. The astigmatism of an elec…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.