Method of recording data onto an optical card having a plurality of tracks containing at least one ID section, error correcting code or directory pointer area and method of reproducing data therefrom
US4979159A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 7, 1988 |
| Grant date | Dec 18, 1990 |
| Priority date | — |
| Expiry date | Oct 7, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2220/218
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A large number of tracks (T) are formed on an optical card (200) and user data are recorded as pits on these tracks. By driving this optical card in a reciprocating manner in a direction parallel to the tracks, user data are reproduced. At both the end portions of each track, guide sections (G) in which no pit indicative of information is formed are provided, thus preventing errors in reading occurring at the time of acceleration and deceleration in the reciprocating drive. Identification information (I) for tracks is recorded at the inside portion adjacent to one guide section, and termination information (E) for tracks is recorded at the inside portion adjacent to the other guide section. User data (U) are recorded between the identification information and the termination information. User data is divided into groups comprised of a predetermined number of bits. Unit data blocks in which an error correcting code is added to every group are formed and these unit data blocks are recorded in a distributed manner on the optical card. On the optical card, a directory pointer area (212), a directory area (213) and a data area (214) are provided. Where there is an alteration in the dire…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.