Color picture tube having an improved inline electron gun
US4590403A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 31, 1984 |
| Grant date | May 20, 1986 |
| Priority date | — |
| Expiry date | Aug 31, 2004 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2229/4896
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An improved color picture tube has an inline electron gun for generating and directing three electron beams, a center beam and two side beams, along coplanar paths toward a screen of the tube. The gun includes prefocus lens electrodes and main focus lens electrodes for focusing the electron beams. The main focus lens is formed by two spaced electrode members. The improvement includes the combination of features related to these two electrode members. One of the electrodes forming the main focus lens is an internal conductive coating on the neck. The other electrode includes three parts. First, there is a cylindrical portion that is smaller in diameter than the neck and is located in overlapped relation with respect to the conductive internal coating. Second, an apertured portion of the electrode includes three inline apertures which are aligned with the electron beam paths. And third, means are located between the cylindrical and apertured portions for controlling the astigmatism of the focus of the two side beams.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.