Patent · US Expired

Magneto-optical recording and reproducing method, magneto-optical memory apparatus and magneto-optical recording medium therefor

US5270987A · kind A · utility

18Cited by
21References
53Claims
0Family size

Assignee

Inventors

Key dates

Filing dateApr 17, 1990
Grant dateDec 14, 1993
Priority date
Expiry dateApr 17, 2010

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG11B11/10571
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

A magnetic field of a polarity corresponding to information to be recorded is applied while a recording spot having a high energy is irradiated to a magneto-optical recording medium to record domains representing the information along a track. The recorded domains are read out by a reproducing spot having a lower energy than the recording spot and a high resolution power along the track. A recording head has an optical system for irradiating the recording spot having the high energy to the magneto-optical recording medium and a magnetic head for applying a magnetic field having a polarity thereof switched in accordance with the information to be recorded, to an irradiation area of the recording spot, a reproducing head has an optical system for irradiating the reproducing spot having the low energy by a laser beam having a wavelength of no larger than 600 nm and a magneto-optical signal detector for detecting a displacement of a polarization plane of a reflected light of the reproducing spot to read out the recording domains. The magneto-optical recording medium is made of a recording film having a multi-layer structure of alternate lamination of metal layers and dielectric layers.

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