Amplitude adjusting equipment in a signal translation line
US4544896A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 11, 1985 |
| Grant date | Oct 1, 1985 |
| Priority date | — |
| Expiry date | Mar 11, 2005 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/648
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An amplitude-adjusting circuit used for a contrast-adjusting circuit of resistor division type in which a video signal is applied across a pair of series-connected resistors and an output is produced from the junction point of the two resistors. At least one of the resistors is used as a variable resistor. The amplitude-adjusting circuit comprises a current source for supplying a constant current steadily between the terminals of the variable resistor, a high-gain amplifier for controlling the resistance value of the variable resistor, and a filter for separating the video signal component from the change of the value of the variable resistor represented by a voltage change, and introducing the resistance change to the high-gain differential amplifier.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.