Disc-shaped recording medium, cutting apparatus for same, and disc drive
US7486607B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 13, 2006 |
| Grant date | Feb 3, 2009 |
| Priority date | — |
| Expiry date | Jan 5, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2220/257
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
There is provided an optical disc having preformed thereon a spiral wobbled track as a grove and/or land along with data is to be recorded. The track is wobbled for a series of predetermined signal units each composed of an FSK information bit part based on a waveform resulted from FSK modulation of information bit and a singe-frequency part based on a waveform of a single frequency. The FSK modulation uses two different frequencies of which the one is the same as the single frequency and the other is different from the single frequency. These different frequencies are in such a relation that each of them has an even number of wobbles and an odd number of wobbles alternately in a predetermined cycle.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.