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US5237547A Expired / Lapsed US ⏱️ 0.0 years remaining

Multi-head magneto-optical disk apparatus

Assignee: Nikon Corp
•
Filing: 1988-10-03
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Granted: 1993-08-17
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Expires: 2008-10-03
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Abstract

Abstract A magneto-optical disk apparatus in which a magneto-optical disk is loaded, data can be recorded on the magneto-optical disk, the data recorded on the magneto-optical disk can be reproduced and the data recorded on the magneto-optical disk can be erased includes a plurality of head devices for applying beams to the magneto-optical disk, the number of the head devices being an even number, a control device for controlling the plurality of head devices so that respective ones of the plurality of head devices apply beams to different ones of a plurality of annular areas on the magneto-optical disk, the number of the annular areas being the same as the number of the head devices, the control devices having a plurality of supporting devices for supporting each two of the plurality of head devices thereon, the two head devices supported on the plurality of supporting devices being supported so as to apply beams to two recording areas which are not adjacent to each other, and an applying device for applying a magnetic field to the plurality of annular areas, the applying device applying a magnetic field to the magneto-optical disk in a predetermined direction when the data is recorded on the magneto-optical disk, and changing the direction of the magnetic field applied to the magneto-optical disk to the direction opposite to the predetermined direction when the data recorded on the magneto-optical disk is erased.

Inventors

  • 👤 Hiroya Ohkuma
  • 👤 Tomohisa Hasumi

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-08 14:40
CPC Classifications
G; G11; G11B; G11B11/00; G11B11/10; G11B11/105; G11B11/1055; G11B11/10552; G11B11/10595; G11B19/00; G11B19/02; G11B7/00; G11B7/08; G11B7/085; G11B7/0857

Claims Analysis

Total Claims: 3
Claim 1
Independent Claim 190 words
An apparatus comprising: two magneto-optical disk devices in each of which a magneto-optical disk is loaded, said magneto-optical disk having a plurality of annular recording areas disposed at different distances, respectively, from a center of said magneto-optical disk, each of said two devices having an even number of head means for applying beams to said magneto-optical disk to record data on said magneto-optical disk, to reproduce data recorded on said magneto-optical disk and output reproducing signals, and to erase data recorded on said magneto-optical disk, control means for controlling said head means so that said head means apply beams to different ones, respectively, of said plurality of annular areas on said magneto-optical disk, and a plurality of applying means for applying a magnetic field to said magneto-optical disk, and wherein each of said applying means applies a magnetic field to said magneto-optical disk in a predetermined direction when data is recorded on said magneto-optical disk and applies a magnetic field to said magneto-optical disk in the opposite direction when data recorded on said magneto-optical disk is erased; and means for combining the reproducing signals from said two magneto-optical disk devices.
Claim 2
Independent Claim 190 words
An apparatus comprising: two magneto-optical disk devices in each of which a magneto-optical disk is loaded, said magneto-optical disk having a plurality of annular recording areas disposed at different distances, respectively, from a center of said magneto-optical disk, each of said two devices having an even number of head means for applying beams to said magneto-optical disk to record data on said magneto-optical disk, to reproduce data recorded on said magneto-optical disk and output reproducing signals, and to erase data recorded on said magneto-optical disk, control means for controlling said head means so that said head means apply beams to different ones, respectively, of said plurality of annular areas on said magneto-optical disk, and a plurality of applying means for applying a magnetic field to said magneto-optical disk, and wherein each of said applying means applies a magnetic field to said magneto-optical disk in a predetermined direction when data is recorded on said magneto-optical disk and applies a magnetic field to said magneto-optical disk in the opposite direction when data recorded on said magneto-optical disk is erased; and means for combining the reproducing signals from said two magneto-optical disk devices.
Claim 3
Dependent Claim 45 words
An apparatus according to claim 1, wherein said control means has a plurality of supporting means, each supporting a corresponding pair of said plurality of head means so as to apply beams to two annular areas which are separated by at least another annular area.

References Cited (Backward Citations)

US4460988A Cited
US4788671A Cited
US4841502A Cited
US4845696A Cited
US4807204A Cited
US4868802A Cited
US4802021A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1996-08-16 1997-02-15 1997-08-17 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2000-08-16 2001-02-15 2001-08-17 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2004-08-16 2005-02-15 2005-08-17 $7700.00 Window Closed / Lapsed

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