Color display system having an electron gun with dual electrode modulation
US4877998A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 27, 1988 |
| Grant date | Oct 31, 1989 |
| Priority date | — |
| Expiry date | Oct 27, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2229/4896
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An improved color display system includes a cathode-ray tube and a magnetic deflection yoke positioned on the tube. The tube includes an envelope having an inline electron gun for generating and directing three inline beams along initially coplanar paths toward a screen on an interior surface portion of the envelope. The gun includes a plurality of spaced electrodes which comprise three lenses. The first lens includes a beam-forming region for providing substantially symmetrical beams to a second lens. The second lens includes a first modulation electrode for providing asymmetrically-shaped beams to a third, or main, lens. At least one and preferably two dynamic voltage signals are applied to the modulation electrode of the second lens. Another dynamic voltage signal is applied to a second modulation electrode of the third lens. The voltage signals are related to the deflection of the beams and improve the electron beam spot size at the periphery of the tube screen.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.