Optical disk device
US5777967A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 5, 1996 |
| Grant date | Jul 7, 1998 |
| Priority date | — |
| Expiry date | Apr 5, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/005
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A phase error between an information signal including a reference signal that can be detected asynchronously and a synchronized signal that is synchronously produced from the information signal is detected, and a signal in response to an absolute value of the phase error is produced. Further, a defect detecting signal is produced in response to the absolute value of the phase error. Therefore, whether a pulse signal exceeding a maximum value of the pulse width of the information signal, that is, a pulse signal exceeding the pulse width of the reference signal, is detected or not, it is possible to detect that the signal reproduction enters a defect region immediately after the entry. Accordingly, a defect with noise or a track jumping can be detected rapidly. Furthermore, an information transition interval of the information signal is measured for a prescribed period of time, and the defect detecting signal is terminated in response to a measured value of a time length of the reference signal that is detected in the prescribed period of time, in other words, the passing of the signal reproduction through the defect region is detected with reference to the synchronization of the ref…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.