Cathode ray tube for achieving small electron beam landing deviation
US6720723B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 15, 2001 |
| Grant date | Apr 13, 2004 |
| Priority date | — |
| Expiry date | Oct 31, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J29/06
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A cathode ray tube including an internal magnetic shield in the shape of a hollow rectangular frustum including two long sides opposite to each other and two short sides opposite to each other, having an opening at its top and bottom attached to a mask and a frame. Each long side has a long side extension at a horizontal center located at the top of the internal magnetic shield where an electron beam enters the internal magnetic shield. The long side extensions enable the magnetic shield to reduce the deviation of an electron beam within the magnetic shield caused by an external magnetic field such as that caused by terrestrial magnetism.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.