Waveform equalizer for a reproduction signal obtained by reproducing marks and non-marks recorded on a recording medium
US6678230B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 29, 2001 |
| Grant date | Jan 13, 2004 |
| Priority date | — |
| Expiry date | Oct 29, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2020/1484
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Even with an asymmetric reproduction waveform, or under the noisy environment, an accurate equalizing error is found and temporary judgment value for adaptively controlling the coefficient of FIR filter is accurately outputted. A waveform equalizer for equalizing a waveform of a reproduction signal obtained by reproducing marks and non-marks recorded on a recording medium is provided. The equalizer includes: a detector which detects asymmetry of the reproduction signal arising from physical profiles of the marks and non-marks and outputs a detection signal representing asymmetric amount; a discriminator which discriminates the marks and non-marks based on the reproduction signal to output a discriminated signal; and a selector which calculates a first and second coefficient multiplied by the reproduction signal of the marks and non-marks based on the detection signal, which are different. The selector selects one of the first and second coefficients based on the discriminating signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.