Directional filter for a display screen, the method for manufacturing same and a display system, a cathode-ray tube in particular, provided with such a filter
US4342821A · kind A · utility
12Cited by
8References
6Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jul 18, 1980 |
| Grant date | Aug 3, 1982 |
| Priority date | — |
| Expiry date | Jul 18, 2000 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S430/151
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
For improving the contrast of information displayed on the screen, there is placed in front of this latter a filter comprising a matrix of channels pierced in a photosensitive glass plate. The pierced plate is covered over the whole of its surface with a blackened deposit so as to reduce to the maximum its coefficient of reflection. Thus filters can be formed readily on request, according to the direction of observation in particular, with a good coefficient of transmission and improved contrast.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.