Test disk having defect patterns uniformly distributed in recording areas
US5526341A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 26, 1994 |
| Grant date | Jun 11, 1996 |
| Priority date | — |
| Expiry date | Jul 26, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B33/10
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A test disk having defect patterns uniformly arranged in recording areas is produced by a production method including: producing a stamper having a plurality of data pits in accordance with test data signals recorded on the test disk; radiating laser light to the stamper by using a laser system so that a plurality of small patterns are produced at laser-light exposed portions along first lines on the stamper, to form interruptions, which interrupt the data pits on the stamper, in accordance with the small patterns; and performing injection molding with plastic material to produce a disk based on the stamper, so that the disk has interruptions corresponding to the interruptions of the stamper, and the interruptions of the disk are included in a recording layer of the disk.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.