Optical servo writing
US6445667B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 11, 2000 |
| Grant date | Sep 3, 2002 |
| Priority date | — |
| Expiry date | Jul 11, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/00745
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The present invention relates to a method for servo writing an optical or magneto-optical medium where a data path is defined by transmitting a laser beam onto the medium to change the crystalline structure at preselected portions. These portions can guide an optical head along the data path. Embodiments include using a far-field laser servo writer to transmit a laser beam in combination with a high numerical aperture, using a far-field laser servo writer to transmit a laser beam in combination with a solid immersion lens, using a near-field laser servo writer to emit a laser beam in combination with a solid immersion lens, creating a sub-wavelength aperture for emitting a laser beam onto the medium, lithographic and maskless lithographic techniques. The present invention also relates to a medium for the storage of data which has portions of its substrate with a different crystalline structure than the rest of the substrate of the medium, so that these portions of the substrate can serve as optically created servo fields for a tracking device.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.