Optical disk unit
US5157645A · kind A · utility
13Cited by
4References
4Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 4, 1990 |
| Grant date | Oct 20, 1992 |
| Priority date | — |
| Expiry date | Apr 4, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/08541
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical disk unit is incidence a light spot upon an optical disk. The light spot is radially moved to cross tracks formed on the optical disk. The tracks are provided with specific access marks. The number of access marks passed by the light spot as well as the number of tracks crossed by the light spot until a change is found in a detected access mark are counted. The latter number is divided by the former number and multiplied by a coefficient to provide a speed signal indicative of a speed of the light spot relative to the optical disk.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.