Overwrite capable magnetooptial recording apparatus
AssigneeNikon Corporation
InventorsMasatoshi Sato, Jun Saito, Hideki Akasaka
Life of this patent
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Abstract
An overwrite capable magnetooptical recording apparatus comprises a moving magnetooptical recording medium to which is applied an initial magnetic field and a laser beam which irradiates the moving medium. The beam intensity is modulated, in accordance with binary data to be recorded, between a high beam intensity level that provides the medium with a first temperature suitable for forming one of a first bit having upward-magnetization and a second bit having downward-magnetization, and a low beam intensity level that provides the medium with a second temperature suitable for forming the other bit. A bias magnetic field is applied to a portion of the medium irradiated by the beam.
Claims3
An overwrite capable magnetooptical recording apparatus characterized by comprising:
- (a) means for moving a magnetooptical recording medium;
- (b) initial field applying means for applying an initial magnetic field to the moving medium;
- (c) a laser beam source for radiating a laser beam to the moving medium;
- (d) means for pulse modulating a beam intensity of the laser beam, before the beam reaches the medium, in accordance with binary data to be recorded to obtain (1) high level that provides, to said medium, a first temperature suitable for forming one of a first bit having upward-magnetization and a second bit having downward-magnetization, and to obtain (2) low level that provides, to said medium, a second temperature suitable for forming the other of said first and second bits;
- and
- (e) bias field applying means for applying a bias magnetic field to a portion of the medium irradiated by the beam.
Dependencies are inferred from the claim text.