Browse Prior Art Database

Magneto Optic Readout of Crosstape Recording

IP.com Disclosure Number: IPCOM000081083D
Original Publication Date: 1974-Apr-01
Included in the Prior Art Database: 2005-Feb-27
Document File: 2 page(s) / 60K

Publishing Venue

IBM

Related People

Grant, D: AUTHOR

Abstract

The shown mandrel 10 with optics mounted in rotor 12 may be used to magneto-optically read out magnetic tape helically wrapped around the mandrel. The surface of the mandrel 10 is porous so as to provide an air bearing between the tape, not shown, as it is moved around the mandrel 10.

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Magneto Optic Readout of Crosstape Recording

The shown mandrel 10 with optics mounted in rotor 12 may be used to magneto-optically read out magnetic tape helically wrapped around the mandrel. The surface of the mandrel 10 is porous so as to provide an air bearing between the tape, not shown, as it is moved around the mandrel 10.

Strip 14 is a magnetic transfer film coated on the face of ring prism 16. The ring prism 16 is fixedly attached to the mandrel 10. Magnetization from the magnetic tape transfers to the thin film 14 as the tape moves around the mandrel.

The magnetization in the thin film 14 is magneto-optically read out by a radiant energy beam 18 that passes down through the center of the mandrel 10. Filters 20 and 22 are provided to maintain linear polarization of the light with respect to the rotor axis as the rotor 12 rotates inside the mandrel. Prisms 24 and 26 are also attached to the rotor 12. Prism 24 acts to reflect the light up to the thin film 14, while prism 26 acts to direct reflected light from the thin film out of the end of rotor 12. The magneto-optic interaction between the polarized light and the thin film 14 takes place as the light reflects off of the thin film.

Lenses 28 and 30 are mounted on the rotor 12 to direct the light to the thin film 14 and pick up light reflected from the thin film, respectively. In addition, if desired, a conical correction plate could be inserted between lens 28 and ring 16 to compensate for optical aberrati...