Cathode-ray tube
US4379251A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 21, 1980 |
| Grant date | Apr 5, 1983 |
| Priority date | — |
| Expiry date | Nov 21, 2000 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J29/81
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
In a cathode-ray tube for displaying colored pictures comprising in an evacuated envelope means to generate a number of electron beams, a display screen comprising a number of regions luminescing in different colors, and color selection means comprising a large number of apertures which assign each electron beam to luminescent regions of one color, in which color selection means a magnetic quadrupole field is generated to form a magnetic quadrupole electron lens in each aperture, which luminescent regions have the shape of substantially parallel strips the longitudinal direction of which is substantially parallel to the defocusing direction of the quadrupole lens, characterized in that the apertures are elongate, substantially hexagonal and symmetrical relative to their longitudinal axes and are situated with their longitudinal axes in a number of parallel rows which extend substantially parallel to the strips and the apertures of two juxtaposed rows are shifted relative to each other, it is possible, in spite of the large transmission of the color selection means, to obtain a display screen having very uniform phosphor strips.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.