Disk apparatus having a read error retry function
US5386405A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 22, 1993 |
| Grant date | Jan 31, 1995 |
| Priority date | — |
| Expiry date | Feb 22, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2020/183
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A disk apparatus having a readout circuit for providing readout data signals and capable of immediately detecting runaway of a readout clock signal generated from a VFO (Variable Frequency Oscillator) in the readout circuit if such occurs. The disk apparatus is free from a read error due to a permanent defect on a disk, e.g., an optical disk, or other causes. The disk apparatus includes a head for picking up signals from a disk, and a readout circuit for providing a readout signal and a readout clock signal, including a digitizing circuit for receiving and digitizing a data signal picked up by the head into a binary data signal, a reference clock generator for generating a reference clock signal and a variable frequency oscillator for receiving a read-gate signal, the digitized binary data signal and the reference clock signal and generating a readout data signal and a readout clock signal, each synchronized with the reference clock signal. The disk apparatus further includes a detecting circuit for supplying the read-gate signal to and receiving the reference clock signal and the readout clock signal from the readout circuit and for detecting that a synchronizing operation in the …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.