AGC circuit and recording and reproducing apparatus using AGC circuit
US5448424A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 15, 1994 |
| Grant date | Sep 5, 1995 |
| Priority date | — |
| Expiry date | Feb 15, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B20/1252
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An AGC circuit is provided with a variable gain amplifier which changes an amplification gain of an input signal in accordance with an instruction; an extraction unit for extracting a value of an output of the variable gain amplifier at a predetermined interval; and a variable gain control unit for instructing the amplification gain of the variable gain amplifier in a manner such that the amplitude of the input signal is equal to a predetermined amplitude on the basis of the value extracted by the extraction unit. The variable gain control unit is provided with an error signal output device for squaring the value extracted by the extraction unit and for generating an error signal to instruct the amplification gain of the variable gain amplifier in a manner such that the amplitude of the input signal is equal to a predetermined amplitude on the basis of the square value and a square value just before it; and an integrating device for integrating the error signal from the error signal output device and for instructing the amplification gain of the variable gain amplifier.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.