In-line type electromagnetic focusing cathode-ray tube
US4473773A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 28, 1981 |
| Grant date | Sep 25, 1984 |
| Priority date | — |
| Expiry date | Jul 28, 2001 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J29/68
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An improved in-line type electromagnetic focusing cathode-ray tube which comprises magnetic yokes, a focusing magnetic field generating permanent magnet, a deflecting magnetic field control element and a cup-shaped spacer member for separating the magnetic yokes from the deflecting magnetic field control element. The deflecting magnetic field control element is disposed at a distance l.gtoreq.0.26 D from an end of the magnetic yoke closest to a fluorescent screen, where D is an outer diameter of the magnetic yoke, so that a beam spot on the fluorescent screen has substantially circular shape to attain an excellent focusing characteristic.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.