| US 7,492,550 B2 | ||
| Magnetic recording head and method for high coercivity media, employing concentrated stray magnetic fields | ||
| Vladimir Nikolaevich Samofalov, Kharkov (Ukraine); Leonid Zakharovich Lub'yaniy, Kharkov (Ukraine); Evgeniy Ivanovich Il'yashenko, Moscow (Russian Federation); and Audun Ramstad, Oslo (Norway) | ||
| Assigned to Tandberg Storage ASA, (Norway) | ||
| Filed on Nov. 18, 2003, as Appl. No. 10/715,635. | ||
| Prior Publication US 2006/0187580 A1, Aug. 24, 2006 | ||
| Int. Cl. G11B 5/127 (2006.01) | ||
| U.S. Cl. 360—125 | 8 Claims |
| 1. A write head for unidirectional overwriting on a medium magnetizable in a longitudinal direction, said medium having a
surface and moving in a single medium movement direction, said write head comprising:
an inductive write element supplied with a current modulated with information to produce a basic magnetic field that embodies
said information, said inductive write element having a gap therein;
a first magnet pair of two permanent magnets disposed in said gap with respective magnetization comprising magnetization components
perpendicular to the surface of the recording medium of said two permanent magnets in said first pair that are oriented oppositely
to each other, said first magnet pair producing a first stray magnetic field and the two permanent magnets thereof being composed
of permanent magnetic material selected so that a sum of said first stray magnetic field and said basic magnetic field is
sufficient to longitudinally magnetize said recording medium only when said inductive write element is supplied with a predetermined
current, and to produce substantially no erasure in said recording medium when said write element is supplied with no current
or a current that is negative compared to said predetermined current; and
a second magnet pair of two permanent magnets disposed upstream of said inductive write element relative to said direction
of medium movement, with respective magnetizations of said two permanent magnets in said second magnet pair comprising magnetization
components that are oriented oppositely to each other in a direction perpendicular to the surface of the recording medium,
with the respective magnetizations of said two permanent magnets in said second magnet pair being oriented oppositely to the
respective magnetizations of said two permanent magnets in said first magnet pair, said second magnet pair producing a second
stray magnetic field having a strength sufficient to longitudinally magnetize said recording medium for recording said information
on said recording medium.
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