Stanley H Charap

US Patent:

60116641, Jan 4, 2000

Filed:

Aug 31, 1995

Appl. No.:

8/521972

Inventors:

Mark Howard Kryder - Bradford Woods PA
Stanley H. Charap - Pittsburgh PA

Assignee:

Carnegie Mellon University - Pittsburgh PA

International Classification:

G11B 502
G11B 900
G01R 3300
G01N 2782

US Classification:

360 59

Abstract:

Techniques for ultrahigh density writing on an erasable magnetic medium include using a micromachined mechanism having two probes for writing to the medium. Use of the two probe embodiment eliminates the need to change the magnetic orientation of the probe. In another embodiment, a single probe is provided which is heated to the vicinity of its Curie temperature to enable the magnetic orientation of the probe to be switched. The probe may be heated to its Curie temperature through the use of a heating element or a focused laser. In another embodiment of the present invention, either the magnetic orientation of the probe or the magnetic orientation of the medium may be switched through the combination of a static magnetic field, a radio frequency magnetic field and, under certain circumstances, the magnetic field of the probe. In all cases, the writing techniques enable information to be written to a magnetic medium in a manner which enables the information to be erased and the medium rewritten.