Patent · US Expired

Method of and apparatus for the reading of magnetically stored information

US5016992A · kind A · utility

1Cited by

6References

20Claims

0Family size

Assignee

Forschungszentrum Jülich GmbH · DE

Inventors

Theo Woike · Euskirchen, DE
Detlef Kerkmann · Altena, DE
Thomas Beier · Aschendorf, DE
Wolfgang Krasser · Jülich, DE
Danilo Pescia · Jülich, DE

Key dates

Filing date	Mar 13, 1990
Grant date	May 21, 1991
Priority date	—
Expiry date	Mar 13, 2010

Classification

Technology area (CPC G)Physics
CPC primaryG11B11/10515
WIPO fieldAudio-visual technology
WIPO sectorElectrical engineering

Abstract

A magnetic storage medium is read by incident polarized light and reflected outgoing light defining a common plane. The polarized incident light preferably has a polarization vector at 40.degree. to 50.degree. to this plane and at the storage medium, the magnetization is in a direction perpendicular to the plane. The preamplified output signal V.sub.M from the photodiode transducing the outgoing light beam has a fixed value V.sub.O subtracted therefrom where V.sub.O is a function of the sensitivity and resolving power of the electronic circuitry. The signal V.sub.M -V.sub.O is then amplified and processed to represent the stored data.

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