Method of driving a flat type of cathode ray tube to provide uniformity of electron beam emission characteristics for a plurality of beam sources
US4694225A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 30, 1986 |
| Grant date | Sep 15, 1987 |
| Priority date | — |
| Expiry date | Sep 30, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/12
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method of producing uniformity of emission a characteristics of a plurality of electron beam sources in a cathode ray tube, by deriving and storing data values for producing respective correction voltages to be applied to modify the emission characteristics. Each data value is obtained by sensing a current which flows through one of the control electrodes when a high voltage electrode is set to a relatively low potential, comparing this current with a reference value and storing the difference for use in subsequently producing a correction voltage. Data values are derived during successive time intervals, with corresponding correction voltages being successively applied to achieve feedback operation, for greater correction accuracy.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.