Patent · US Expired

Optical recording method for data cards

US4910725A · kind A · utility

59Cited by
14References
11Claims
0Family size

Assignee

Inventors

Key dates

Filing dateOct 17, 1986
Grant dateMar 20, 1990
Priority date
Expiry dateOct 17, 2006

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG11B27/36
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

A method of recording data on a card in which track indicia are laser recorded by a user on at least one end of a card prerecorded with tracks only. Track indicia include start and stop marks defining usable recordable areas, synchronization marks, error codes and track numbers and track termination codes. Start and stop marks may be series of lines recorded in a pattern across the tracks and in addition to demarcating usable recordable areas of the card may indicate the location of track numbers and data areas as well as the particular encoding scheme used on the card. Data blocks may be written on entire tracks or in sectors. When recording errors are detected, the data block is rewritten in a new sector or on another track using the same track number.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.