Patent EP0195227A2 successfully refreshed from Google Patents.
EP0195227A2
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Magneto-optical disc memory
Assignee: Hitachi Ltd
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Filing: 1986-02-07
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Granted: —
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Expires: 2006-02-07
Abstract
Abstract Magneto-optical disc memory. In a recording medium which has a disc-like substrate (1) and a magnetic film (2) provided thereon so that the data can be written thereon relying upon the change in the direction of magnetization, a magneto-optical disc-memory wherein said magnetic film (2) is provided with spiral or concentric guide tracks (21) which have said recording medium with a magnetic pole of a direction opposite to that of a recording region (22) between said guide tracks, and which further have an optical head that can be relatively moved in the radial direction of said recording medium, said optical head being equipped with an optical system (11, 12, 13) which applies a light beam (14) onto the recording region of said recording medium to write or reproduce the data and which also applies a light beam (15) to erase the data, and said optical head being further equipped with a detector system (16, 17, 18) which detects the direction of polarization of the light beam reflected by said recording medium.
Inventors
- 👤 Yoshinori Miyamura
- 👤 Tsuyoshi Kato
- 👤 Masahiro Ojima
- 👤 Toshimitsu Kaku
- 👤 Yoshito Tsunoda
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 12:44
CPC Classifications
G; G11; G11B; G11B11/00; G11B11/10; G11B11/105; G11B11/10532; G11B11/10534; G11B11/10536; G11B11/10502; G11B11/10517; G11B11/10519; G11B11/10582
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
169 words
In a magneto-optical recording medium which has a disc-like substrate (1) and a magnetic film (2) provided thereon so that the data can be written thereon relying upon the change in the direction of magnetization, a magneto-optical disc memory wherein said magnetic film (2) is provided with guide tracks (21) which have said magneto-optical recording medium with a magnetic pole of a direction opposite to that of a recording region (22) between said guide tracks, and which further have an optical head that can be relatively moved in the radial direction of said recording medium, said optical head being equipped with an optical system (11, 12, 13) which applies a light beam (14) onto the recording region (22) of said recording medium to write or reproduce the data and which also applies a light beam (15) to erase the data, and said optical head being further equipped with a detector system (16, 17, 18) which detects the direction of polarization of the light beam reflected by said recording medium.
Claim 2
Dependent Claim
169 words
In a magneto-optical recording medium which has a disc-like substrate (1) and a magnetic film (2) provided thereon so that the data can be written thereon relying upon the change in the direction of magnetization, a magneto-optical disc memory wherein said magnetic film (2) is provided with guide tracks (21) which have said magneto-optical recording medium with a magnetic pole of a direction opposite to that of a recording region (22) between said guide tracks, and which further have an optical head that can be relatively moved in the radial direction of said recording medium, said optical head being equipped with an optical system (11, 12, 13) which applies a light beam (14) onto the recording region (22) of said recording medium to write or reproduce the data and which also applies a light beam (15) to erase the data, and said optical head being further equipped with a detector system (16, 17, 18) which detects the direction of polarization of the light beam reflected by said recording medium.
Claim 3
Dependent Claim
39 words
A magneto-optical disc memory according to claim 1, wherein the spot of a light beam (15) for erasing the data is selected to be wider than the spot of a light beam (14) for writing or reproducing the data.
Claim 4
Dependent Claim
48 words
A magneto-optical disc memory according to claim 1, wherein the spot of a light beam (15) for erasing the data is located relatively in front of the spot of a light beam (14) for writing or reproducing the data in a direction in which said recording medium rotates.
Claim 5
Dependent Claim
48 words
A magneto-optical disc memory according to claim 2, wherein the spot of a light beam (15) for erasing the data is located relatively in front of the spot of a light beam (14) for writing or reproducing the data in a direction in which said recording medium rotates.
Claim 6
Dependent Claim
30 words
A magneto-optical disc memory according to claim 1, wherein said optical system obtains the light beams for writing, reproducing and erasing the data from the same source of light (11).
Claim 7
Dependent Claim
30 words
A magneto-optical disc memory according to claim 2, wherein said optical system obtains the light beams for writing, reproducing and erasing the data from the same source of light (11).
Claim 8
Dependent Claim
43 words
A magneto-optical disc memory according to claim 1, wherein said optical system is Equipped with means (12-1) which divides the same light beam into the light beam (14) for writing or reproducing the data, and the light beam (15) for erasing the data.
Claim 9
Dependent Claim
20 words
A magneto-optical disc memory according to claim 7, wherein means (12-1) for dividing the light beam is an acousto-optic modulator.
Claim 10
Dependent Claim
49 words
A magneto-optical disc memory according to claim 1, wherein said optical system focuses the light beam (15) for erasing the data onto said recording region (22) by using means (13) which focuses the light beam ( 1 4) for writing or reproducing the data onto said recording region (22).
References Cited (Backward Citations)
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