Optical disk having an erased-state indicator and optical disk apparatus for reducing frequency of disk erasing operation
US5617393A · kind A · utility
27Cited by
5References
15Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Dec 28, 1994 |
| Grant date | Apr 1, 1997 |
| Priority date | — |
| Expiry date | Dec 28, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2220/2537
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical disk includes a user accessible area having a plurality of blocks and flag data recorded on the optical disk. The flag data indicates whether or not each of the blocks is in an erased state in which there is no recorded data. A flag area stores the flag data, and area data indicating that the optical disk has the flag area is recorded on the optical disk.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.