Rewritable data storage medium having erasable identification marks
US6986150B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 22, 2001 |
| Grant date | Jan 10, 2006 |
| Priority date | — |
| Expiry date | May 15, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B20/1217
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The rewritable data storage medium (1) has a rewritable recording layer (9) provided with a tracking structure (8). Said layer (9) has a data recording area (5). An erasable identification mark is present in an identification mark area (4, 4′) other than the data recording area (5). The data recording area (5) has a first tracking structure (8′), whereas the identification mark area (4, 4′) is substantially free from a tracking structure or has a second tracking structure (8″) substantially different from the first tracking structure (8′).Thus erasure of the identification mark is practically impossible, because the location of the erasing spot of a recorder cannot be controlled precisely in radial direction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.