Dynamic focus voltage disabling circuit
US6118233A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 7, 1998 |
| Grant date | Sep 12, 2000 |
| Priority date | — |
| Expiry date | Aug 7, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N3/26
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A video imaging apparatus includes a source of a periodic dynamic focus voltage blanking signal. A dynamic focus voltage amplifier includes a switch responsive to the dynamic focus voltage blanking signal for applying a dynamic focus voltage to a focus electrode, when the switch is at a first state, and for disabling the application of the dynamic focus voltage, when the switch is at a second state to provide for automatic kine bias measurement. A second switch responsive to the focus voltage blanking signal is coupled to the amplifier for applying a current to a stage of the amplifier, when the dynamic focus voltage is disabled. The applied current adjusts the focus voltage, to a level closer to that established immediately after the dynamic focus voltage is enabled for reducing a transient condition.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.