Color picture tube having inline electron gun with coma correction members
US4730144A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 27, 1986 |
| Grant date | Mar 8, 1988 |
| Priority date | — |
| Expiry date | Aug 27, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2229/4875
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The present invention provides an improvement in a color picture tube having an inline electron gun for generating and directing three inline electron beams, comprising a center beam and two outer beams, along initially coplanar paths toward a screen of the tube. The beams pass through a deflection zone adapted to have two orthogonal magnetic deflection fields established therein. A first of the fields causes deflection of the beams in a first direction perpendicular to the inline direction of the beams, and a second of the fields causes deflection in a second direction parallel to the inline direction of the beams. The gun includes two shunts for shunting portions of both deflection fields around the outer beam paths. Each shunt comprises one magnetically permeable member having an aperture therein. Each shunt completely surrounds one of the electron beam paths. The improvement comprises each shunt being longer in the first direction than in the second direction and being symmetric about a central axis of the shunt that parallels the first direction and symmetric about another central axis of the shunt that parallels the second direction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.