Color cathode ray tube with a reduced dynamic focus voltage for an electrostatic quadrupole lens thereof
US6225765A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 1, 1999 |
| Grant date | May 1, 2001 |
| Priority date | — |
| Expiry date | Apr 1, 2019 |
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 phosphor screen, cathodes, a G1 electrode, a G2 electrode, a G4 electrode, a G5 electrode and an anode for focusing the electron beams on the phosphor screen. The G5 electrode is divided into plural sub-electrodes arranged to be supplied alternately with a first focus voltage and a second focus voltage, at least one electrostatic quadrupole lens is formed between two of the sub-electrodes supplied with the first and second focus voltages, respectively, at least one lens for correcting curvature of the image field is formed between two of the sub-electrodes supplied with the first and second focus voltages, respectively. The G4 electrode, the G5 electrode and the phosphor screen satisfy following inequalities: 0.0625.times.L (mm).ltoreq.B-20A/(3.phi.).ltoreq.22.00 mm, L(mm).ltoreq.352 mm, where A (mm) is an axial length of the G4 electrode, .phi.(mm) is an average of horizontal and vertical diameters of a center electron beam aperture in the G4 electrode, B(mm) is an axial length from a cathode side and to a phosphor screen side end of the G5 electrode, and L(mm) is an axial distance from the phosphor screen side end of the G5 electrode to a cente…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.