Patent · US Expired

High density magnetic head

US4618901A · kind A · utility

23Cited by
5References
6Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJul 19, 1983
Grant dateOct 21, 1986
Priority date
Expiry dateJul 19, 2003

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG11B5/332
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

A magnetic head for digital signal recording/reproducing (FIG. 11) having a C-ring shaped core (11.1) with a gap (G) for introducing leakage flux of a recording medium, a conductor (11.2, Y) for generating bias flux in hard magnetization axis of the core (11.1), apparatus (10.3, 11.3) for illuminating the core (11.1) with polarized optical beam, apparatus (11.4) for analyzing beam reflected by the core to convert polarization rotation to optical strength, and photo-detector (12.5) for providing electrical output signal relating to optical strength. The core is small enough to have a single magnetic domain, and is magnetized in the whole area because of the presence of the bias flux in spite of weak leakage signal flux, thus, the core has the capability to amplify signal flux, thus, the present head has high sensitivity and is capable of detecting flux in small area to be used for high density recording higher than 8000 bits/mm.

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