Bias current setting apparatus in a magnetic recording and reproducing apparatus
US4262313A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 2, 1979 |
| Grant date | Apr 14, 1981 |
| Priority date | — |
| Expiry date | Mar 2, 1999 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/03
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A bias current setting apparatus is used in a magnetic recording and reproducing apparatus having a bias current supplying circuit and a magnetic head for recording an audio signal with the bias current on a magnetic tape. The bias current setting apparatus comprises an oscillator for oscillating signals of different frequencies, said signals of different frequencies being recorded and reproduced on and from the magnetic tape in the magnetic recording and reproducing apparatus, a circuit for varying the current value of the bias current, a first detector for detecting the signal of different frequencies which have been recorded and reproduced, a filter for separating a harmonic component of the signal of a frequency which have been recorded and reproduced, a second detector for detecting the output signal of the filter a converter for converting the output signals of the first and second detector which have been selectively supplied thereto into digital signals, and a computer for controlling the bias current setting circuit with a stored program system responsive to the digital signals supplied from the converter thereby varying the bias current value and setting the same at a cur…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.