Recording/reproducing device
US5142521A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 25, 1990 |
| Grant date | Aug 25, 1992 |
| Priority date | — |
| Expiry date | May 25, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2220/2525
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A recording/reproducing device performs the recording/reproduction on a recording medium having an information recording area and a table of contents area. The recording medium is provided with guiding grooves that snake in cycles corresponding to values of absolute addresses. The device divides the information recording area into a plurality of domains. Each domain corresponds to a single sampling frequency with respect to the information being recorded. An electromagnet and an optical head record information in the domain that corresponds to its sampling frequency and records additional information concerning the division in the table of contents. A spindle motor drives the disk which is adjusted such that the velocity of the disk is changed for each domain during recording and reproduction. A demodulator obtains the absolute addresses through demodulation by comparing frequencies determined from the snaking cycles of the guiding grooves with a reference frequency. An operational circuit converts the demodulated absolute addresses in accordance with the velocity of the disk into corrected absolute addresses that represented the period of time which has elapsed since the starting …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.