Magnetic recording and reproducing apparatus including a viterbi detector having a variable reference amplitude value
US6046873A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 18, 1995 |
| Grant date | Apr 4, 2000 |
| Priority date | — |
| Expiry date | Sep 18, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B20/1833
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A magnetic recording and reproduction apparatus, includes a circuit for changing a reference amplitude value of a Viterbi detector. The circuit is used to record and reproduce data with the reference amplitude value displaced from a reference value, thereby measuring the data error rate. Displacement of the reference amplitude from a reference value increases the data error rate, and therefore the data error rate can be measured within a short time. A data error rate with the reference amplitude equal to a reference value is estimated from the data error rate measurement, thereby making it possible to evaluate the degree of accuracy of a magnetic recording and reproduction apparatus. The data error rate is measured with the reference amplitude of the Viterbi detector displaced from a reference value while changing the equalization coefficient value of a waveform equalizer, the cut-off frequency of a low-pass filter and the write precompensation amount of a write precompensation circuit. In this way, the effect of the reproduction channel parameter or the write precompensation amount on the degree of accuracy of the magnetic recording and reproduction apparatus is evaluated, and the…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.