Projection television display tube and device having interference filter
US4683398A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 4, 1985 |
| Grant date | Jul 28, 1987 |
| Priority date | — |
| Expiry date | Nov 4, 2005 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J29/185
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A projection television display tube comprising in an evacuated envelope a display screen on the convexly curved inside of a display window in the wall of the envelope, which display screen comprises a layer of luminescent material and a multilayer interference filter between said material layer and the display window, the filter comprising a number of layers which are alternately high refractive index (H) and low refractive index (L). The filter is composed of at least 6 layers, each having an optical thickness nd, wherein n is the refractive index of the material of the layer and d is the thickness, which optical thickness is between 0.2.lambda..sub.f and 0.3.lambda..sub.f, wherein .lambda..sub.f is equal to p x .lambda., wherein .lambda. is the desired central wavelength which is selected from the spectrum emitted by the luminescent material and p is a number between 1.18 and 1.32.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.