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EP0285461A2
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Magneto-optic recording and reproduction apparatus
Assignee: Mitsubishi Electric Corp
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Filing: 1988-04-05
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Granted: —
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Expires: 2008-04-05
Abstract
Abstract A magneto-optic recording and reproduction apparatus provides a laser beam which is focused onto a storage medium which has three magnetic layers (3, 4, 10). Two of these layers (3, 4) are accessed by the laser beam to read out or write in information while the third layer (10) is premagnetized in the direction parallel to the thickness thereof. The laser beam incident on the layers is controlled to three intensities (a, b, c) for writing and reading information.
Inventors
- 👤 Michihiro Mitsubishi Denki K.K. Tadokora
- 👤 Kazuo Mitsubishi Denki K.K. Okada
- 👤 Hitoshi Mitsubishi Denki K.K. Imai
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 01:03
CPC Classifications
G; G11; G11B; G11B11/00; G11B11/10; G11B11/105; G11B11/10502; G11B11/10504; G11B11/10506; G11B11/10517; G11B11/10519; G11B11/10521; G11B11/10532; G11B11/10534; G11B11/10536
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
107 words
A magneto-optic recording and reproduction apparatus employing means (5) for providing a laser beam for use with a storage medium comprising a substrate (2) and first (3), second (4) and third (10) magnetic layers stacked on the substrate from the side on which the laser beam is incident with the third layer being premagnetized in a uniform direction parallel to the thickness thereof and means (8) for generating a magnetic field for causing the magnetization of the second layer (4) to be reversed at room temperature; characterized by a controller (21) for controlling the intensity of the laser beam to at least three levels (a, b, c).
Claim 2
Dependent Claim
107 words
A magneto-optic recording and reproduction apparatus employing means (5) for providing a laser beam for use with a storage medium comprising a substrate (2) and first (3), second (4) and third (10) magnetic layers stacked on the substrate from the side on which the laser beam is incident with the third layer being premagnetized in a uniform direction parallel to the thickness thereof and means (8) for generating a magnetic field for causing the magnetization of the second layer (4) to be reversed at room temperature; characterized by a controller (21) for controlling the intensity of the laser beam to at least three levels (a, b, c).
Claim 3
Dependent Claim
99 words
Apparatus according to Claim 1, wherein said at least three intensity levels are a first intensity (a) for causing the magnetizations on the first to third layers not to be erased by rises in temperature due to incidence of the laser beam, a second intensity (b) for causing the magnetization only on the first layer to be erased by a rise in temperature due to incidence of the laser beam, and a third intensity (c) for causing the magnetizations on the first and second layers to be erased by rises in temperature due to incidence of the laser beam.
Claim 4
Dependent Claim
28 words
Apparatus according to Claim 1 or 2 wherein the means for providing the laser beam employs an objective lens (5) for focusing the beam onto the storage medium.
Claim 5
Dependent Claim
25 words
Apparatus according to Claim 3 wherein the magnetizing means (8) and the objective lens (5) are located on opposing sides of the storage medium (1).
Claim 6
Dependent Claim
26 words
Apparatus according to Claim 3, wherein the magnetizing means (8) and the objective lens (5) are located on the same side of the storage medium (1).
Claim 7
Dependent Claim
29 words
Apparatus according to any one of Claims 1 to 5, wherein the magnetizing means (8) serves to magnetize the second layer (4) in the direction of the substrate (2).
Claim 8
Dependent Claim
29 words
Apparatus according to any one of Claims 1 to 5, wherein the magnetizing means (8) serves to magnetize the second layer (4) in the direction opposite the substrate (2).
References Cited (Backward Citations)
No citation records indexed.
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