Dynamic electrostatic and magnetic focusing apparatus for a cathode ray tube
US5442263A · kind A · utility
3Cited by
12References
11Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Aug 23, 1994 |
| Grant date | Aug 15, 1995 |
| Priority date | — |
| Expiry date | Aug 23, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2229/703
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Apparatus, associated with a cathode ray tube (CRT), containing both a electrostatic focusing lens and a magnetic focusing lens for maintaining the focus of an electron beam within the CRT at any location on a CRT screen. The apparatus applies a dynamic focusing voltage to an electrostatic focus grid of an electron gun and applies a dynamic focusing current to a magnetic focus coil. The focusing voltage and current vary in accordance with the position of the electron beam on the screen. As such, the electron beam remains focused upon the screen for all beam positions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.