Convergence correcting device capable of coma correction for use in a cathode ray tube having in-line electron guns
US4725763A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 25, 1986 |
| Grant date | Feb 16, 1988 |
| Priority date | — |
| Expiry date | Sep 25, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2229/5687
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A convergence correcting device for correcting mis-convergence of a cathode ray tube having in-line electron guns and, at the same time, correcting coma at the top and bottom of the screen, the device comprising pole pieces provided for the outermost electron beams for producing 4-pole magnetic fields used for convergence correction, a convergence yoke for applying the magnetic fields to the pole pieces, a convergence coil wound on the convergence yoke, a coil for producing a coma correcting magnetic field which cancels a leakage flux created between the right and left pole pieces by the vertical deflection coil, and current sources for supply currents to the coils.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.