Brightness control circuit for display apparatus with color picture tube
US4633145A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 29, 1984 |
| Grant date | Dec 30, 1986 |
| Priority date | — |
| Expiry date | May 29, 2004 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/72
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A brightness control circuit for a color display tube comprises voltage regulating means for varying a voltage between an input terminal and an output terminal thereof in dependence on an externally supplied voltage control signal are provided between cathodes of a color display tube corresponding to primary color signals and an output end of the color display tube drive circuit for supplying drive currents to the individual cathodes of the color display tube, and voltage control signal generating means connected to the voltage regulating means for supplying the voltage control or adjusting signals to the voltage regulating means. The voltage control signal generating means include two regulating means, i.e. first regulating means for changing simultaneously all the voltage control signals supplied to the voltage regulating means corresponding to the primary color signals and second regulating means for varying individually the voltage control signals for each of the color signals. Adjustment of cut-off voltage of the color display tube and adjustment of the white balance in the state of high brightness are performed by the second regulating means while the brightness of a raster s…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.