Apparatus for recording and/or reproducing optical cards
US4852101A · kind A · utility
Inventors
Key dates
| Filing date | Feb 19, 1988 |
| Grant date | Jul 25, 1989 |
| Priority date | — |
| Expiry date | Feb 19, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B20/1809
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An apparatus for recording optical cards wherein checking words or inspection words based upon an error correction code are added to information data signals to be recorded, and signals which have been scrambled are recorded in the form of a block that can be optically read onto a belt-like optical recording medium of a card at intervals of a predetermined number of words that are distributed for a data track, and/or an apparatus for reproducing optical cards wherein signals that are read from the thus recorded optical card by a card reader, are descrambled thereby to reproduce the original data signals. Scrambling consists, for example, of so arranging the words that each is delayed by two words in the data track direction and that they are delayed by k tracks, where k is an integer, in the direction perpendicular to the data track, and placing the word at the head of the block at a position of a word number of which the phase is shifted by one word from the word number at the head of the block when the word that has reached the end of the data track is to be wrapped around to the other end and delayed, and then delaying each word by two words in the data track direction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.