Color picture tube having an inline electron gun with an einzel lens
US4742266A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 20, 1987 |
| Grant date | May 3, 1988 |
| Priority date | — |
| Expiry date | Jul 20, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2229/4896
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The present invention provides an improvement in color picture tubes. Such tubes include an electron gun for generating and directing three inline electron beams, a center beam and two side beams, along initially coplanar paths toward a screen of the tube. The gun includes a plurality of spaced electrodes which form a main focus lens for focusing the electron beams. The improvement comprises the plurality of spaced electrodes which form a main focus lens including three electrodes that form an einzel lens in the path of each electron beam. A first einzel lens electrode includes a first portion having three inline apertures that are set back from a second portion forming a single large aperture through which all three electron beams pass. A second einzel lens electrode includes a first portion having three inline apertures that are set back from a second portion forming a single large aperture through which all three electron beams pass. The second portion of the first einzel lens electrode faces the second portion of the second einzel lens electrode. A second einzel lens electrode also includes a third portion having three inline apertures that are set back from a fourth portion fo…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.