Color picture tube with magnetic focusing system
US4345183A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 20, 1978 |
| Grant date | Aug 17, 1982 |
| Priority date | — |
| Expiry date | Jun 20, 1998 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J29/707
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A pair of disc-shaped members of magnetic material each having three through holes for passing the beams emitted from three electron guns R, G and B are arranged in parallel to each other within the glass neck of a color picture tube. An annular permanent magnet is provided on the outer surface of the glass neck at a position nearest to the outer periphery of each of the disc-shaped members of magnetic material. The annular permanent magnet for magnetizing one of the members has an S pole at its part nearer to the outer surface of the glass tube and an N pole at its part farther from the outer surface of the glass tube, while the other annular permanent magnet for magnetizing the other member of magnetic material has N and S poles nearer to and farther from the glass tube respectively. Thus, the periphery of each through hole of one of the members of magnetic material is magnetized to S pole and that of the other member to N pole, so that lines of magnetic force are produced from the through holes of one member to those of the other member, thereby forming three focusing magnetic lenses with axes thereof coincident with routes of beam travel respectively.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.