Optical filter for cathode ray tube
US5218268A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 15, 1992 |
| Grant date | Jun 8, 1993 |
| Priority date | — |
| Expiry date | Apr 15, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J29/18
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A cathode ray tube has a vacuum envelope which includes a faceplate, an optical filter formed on the faceplate, the optical filter including mainly of SiO.sub.2 and containing a coloring material, and a phosphor layer formed on the inner surface of the faceplate. The optical filter includes silicon having a fluorine-containing group and a siloxane bond at least on the surface thereof, and a maximum light absorption wavelength in a range of 400 to 650 nm is in a region of 575.+-.20 nm, and where the transmissivity for the wavelength of 450 nm is T.sub.450, that for 530 nm is T.sub.530, that for 550 nm is T.sub.550, that for 630 nm is T.sub.630, and that for the maximum absorption wavelength is Tmin, the following relationship is established: EQU Tmin.ltoreq.T.sub.550 .ltoreq.T.sub.530, EQU 1.ltoreq.T.sub.450 /T.sub.539 .ltoreq.2, EQU 1.ltoreq.T.sub.630 /T.sub.530 .ltoreq.2, EQU 0.7.ltoreq.T.sub.450 /T.sub.630 .ltoreq.1.43.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.