Method for reading optical information medium and optical information medium
US6430128B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 20, 2000 |
| Grant date | Aug 6, 2002 |
| Priority date | — |
| Expiry date | Feb 3, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/24085
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The present invention provides a method for determining optimal read power adapted for use in an optical information medium wherein super-resolution readout beyond diffraction limit is conducted. Also provided is an optical information medium adapted for use in such method. In this method, when the readout is conducted under the conditions: LMIN<&lgr;/4NA, and when reading light has a wavelength &lgr;, objective lens of readout optical system has a numerical aperture NA, and minimum mark of the marks constituting the information pattern has a length LMIN, a short mark having a length LS and a long mark having a length LL meeting the relations: LS<&lgr;/4NA, and LL≅&lgr;/4NA are preliminarily formed in the optical information medium, and the optimal power of the reading light is determined on the output when said short mark and said long mark are read.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.