Optical disk reproducing apparatus having a viterbi detector
US6785212B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 31, 2000 |
| Grant date | Aug 31, 2004 |
| Priority date | — |
| Expiry date | Sep 15, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2020/1461
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical disc reproducing apparatus including a viterbi detector for an optical disc in which digital data is stored includes an optical pick-up for reading digital data stored in the optical disc and for generating a high frequency signal, an analog-to-digital converter for sampling and quantizing the high frequency signal, and a viterbi detector for decoding a quantized signal output from the analog-to digital converter and reproducing an eight to fourteen modulation (EFM)/EFM+signal. The viterbi detector includes a branch metric calculator for receiving a signal constituted of n bits, for comparing the signal with previously set three variables, and for calculating a branch metric with respect to the input signal. A path metric update and storage unit receives the branch metric, adds the branch metric to values stored therein, compares the error content of all the possible paths with each other, and stores a metric with respect to the path having the smallest amount of errors. A path memory receives the output signal of the path metric update and storage unit and generates a viterbi decoded recovery signal. A stable eight to fourteen modulation (EFM)/EFM+signal is reproduced.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.