Color cathode ray tube having an improved electron gun
US6445116B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 25, 2000 |
| Grant date | Sep 3, 2002 |
| Priority date | — |
| Expiry date | Feb 21, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2229/4841
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A color cathode ray tube includes a three-color phosphor screen, a shadow mask spaced from the phosphor screen and a three-beam type electron gun. The main lens section includes a focus electrode and an anode facing the focus electrode, each of the focus electrode and the anode has an electrode having a single opening common for three electron beams in an end thereof facing each other and a plate electrode disposed therein. The focus electrode is formed of at least one first sub-electrode adapted to be supplied with a first focus voltage and at least one second sub-electrode adapted to be supplied with a second focus voltage, one of the at least one first sub-electrode and the at least one second sub-electrode faces the anode. The second focus voltage is a fixed voltage superposed with a dynamic voltage varying with beam deflection, and an electrostatic quadrupole lens is formed between a first one of the at least one first sub-electrode and a first one of the at least one second sub-electrode. An inequality V1>H−2×S is satisfied, where V1 and H are vertical and horizontal diameters of the single opening, respectively, S is P×L/Q, P is a horizontal center-to-cente…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.