Optical disc system having improved circuitry for performing blank sector check on readable disc
US6069857A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 27, 1997 |
| Grant date | May 30, 2000 |
| Priority date | — |
| Expiry date | Feb 27, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/0925
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical disc drive system is employed in conjunction with a storage medium having a plurality of data sectors each provided with a header and a data storage area. The system includes a data detection device for retrieving stored data from the storage medium and outputting a data signal, an amplifier for providing a variable gain to the data signal and outputting an amplified data signal, a detector that is responsive to the amplified data signal for evaluating a predetermined one of the sectors to ascertain whether the storage area is blank, and an automatic gain control circuit producing a gain control output for controlling the gain of the amplifier. The control circuit has a first mode and a second mode, the first mode being active during retrieval of the header and the second mode being active during retrieval of the data storage area. The system is further provided with a sampling device for sampling the gain control output during retrieval of the stored data in a respective one of the storage areas containing previously stored data. The sampling device outputs results of the sampling, and a fixed gain control circuit is responsive to the results of the sampling for outputt…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.