Multi-focusing type electron gun for color cathode ray tubes
US5291094A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 12, 1992 |
| Grant date | Mar 1, 1994 |
| Priority date | — |
| Expiry date | Feb 12, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J29/488
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
In a multi-focusing type electron gun in which first through eighth electrodes and a shield cup are provided, the sixth electrode which forms the center of a second unipotential lens is formed by a primary electrode and a corresponding secondary electrode. The center aperture of the primary electrode has a larger inside diameter than lateral apertures thereof, which is equal to the inside diameter of the lateral apertures of the secondary electrode. The center aperture of the secondary electrode has a comparatively smaller inside diameter than the lateral apertures thereof but which is equal to the inside diameter of the lateral apertures of the primary electrode, so that a voltage difference of the second unipotential lens becomes uniform to obtain an expanded focus lens.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.