Clamping apparatus and gain control apparatus
US4982191A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 22, 1990 |
| Grant date | Jan 1, 1991 |
| Priority date | — |
| Expiry date | Mar 22, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M1/181
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
In converting an analog signal to a digital signal, a clamping apparatus is capable of adjusting the DC level of the analog signal to a predetermined value, and a gain control apparatus is capable of adjusting the amplitude of the analog signal to a predetermined value. Each of such clamping apparatus and gain control apparatus is adapted for use particularly in digitizing a video signal and comprises: a detection circuit for detecting the DC level or the amplitude of the signal digitized by an analog-digital converter; a signal conversion circuit for outputting, in accordance with the detection signal, a three-state signal indicative of a high voltage, a lower voltage or a high impedance; an integrator for integrating such three-state signal; and a feedback loop for controlling, by the integrated signal, the analog signal to be inputted to the analog-digital converter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.