Patent · US Expired

Method and device for reading out optically recorded data and compensating for a drastic change in the position of a line to be read

US4855981A · kind A · utility

9Cited by
10References
10Claims
0Family size

Assignee

Inventors

Key dates

Filing dateApr 17, 1986
Grant dateAug 8, 1989
Priority date
Expiry dateApr 17, 2006

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG11B17/34
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

Method and a device for reading out optically recorded data from an optical recording medium having data recording regions defined by reference lines in stripe and plural data tracks arranged in parallel to each other and perpendicular to said reference lines. According to the present inventions, a drastic change in the position of a reference line at a given order within the sensing field is monitored from among plural reference lines covered by the field. If there is any drastic change, the order of the reference line for reading is modified so that the data track to be read can be accurately followed even if the field of the reading sensor is deviated in the direction of the data tracks. It also enables correct data reading by checking whether the position of the reference lines included in the field of the reading sensor is within the preset tolerance.

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