Automatic level adjustment with means for minimizing drop-out effects
US4504870A · kind A · utility
5Cited by
1References
9Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jul 19, 1982 |
| Grant date | Mar 12, 1985 |
| Priority date | — |
| Expiry date | Jul 19, 2002 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B20/04
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A test signal is recorded on a magnetic tape prior to the recording of audio signals and reproduced to allow detection of an average value of the magnitude of the reproduced test signal. A drop-out in the reproduced signal is detected if it occurs during the process of deriving the average value. If the drop-out is not detected, a difference between the average value and a reference value is detected to adjust the signal level of the recorded test signal so that the difference reduces substantially to zero. If a drop-out is detected the average value is renewed by repeating the process of recording and reproducing the test signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.