Patent EP0498459A2 successfully refreshed from Google Patents.
EP0498459A2
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EP
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Magneto-optical medium and recording and/or reproducing apparatus thereof
Assignee: Sony Corp
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Filing: 1992-02-07
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Granted: —
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Expires: 2012-02-07
Abstract
Abstract A magneto-optical recording medium (10) having a recording layer (13), a reproducing layer (11) and an intermediate layer (12) for magnetically coupling the recording layer (13) and the reproducing layer (11) in a stationary state, in which the magnetic coupling between the recording layer (13) and the reproducing layer (11) is lost in an area (14) in which a temperature is increased to be higher than a predetermined temperature by the radiation of a light upon reproducing and in which a recorded information held in the recording layer (13) is read out from the reproducing layer (11) in the radiated area (5) except the area in which the magnetic coupling is lost. This magneto-optical recording medium (13) is characterized in that a Curie temperature of the intermediate layer (12) is selected to be 150°C or more. Also, an apparatus for recording and/or reproducing a magneto-optical recording medium (10) is provided.
Inventors
- 👤 Masumi Ohta
- 👤 Isamu Nakao
- 👤 Toshiki Udagawa
- 👤 Atsushi Fukumoto
- 👤 Shuni Yoshimura
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 13:19
CPC Classifications
G; G11; G11B; G11B11/00; G11B11/10; G11B11/105; G11B11/10595; G11B11/10597; G11B11/10502; G11B11/10515; G11B11/10582; G11B11/10586; G11B19/00; G11B19/02; G11B19/12
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
130 words
A magneto-optical recording medium (10) having a recording layer (13), a reproducing layer (11) and an intermediate layer (12) for magnetically coupling said recording layer (13) and said reproducing layer (11) in a stationary state, in which the magnetic coupling between said recording layer (13) and said reproducing layer (11) is lost in an area (14) in which a temperature is increased to be higher than a predetermined temperature by the radiation of light upon reproducing and in which a recorded information held in said recording layer (13) is read out from said reproducing layer (11) in the radiated area (5) except the area (14) in which said magnetic coupling is lost, characterized in that a Curie temperature of said intermediate layer (12) is selected to be 150°C or more.
Claim 2
Dependent Claim
18 words
The magneto-optical recording medium (10) according to claim 1, wherein said intermediate layer (12) is composed of TbFeCoAℓ.
Claim 3
Dependent Claim
17 words
The magneto-optical recording medium according to claim 1, wherein said intermediate layer (12) is composed of TbFeAℓ.
Claim 4
Dependent Claim
17 words
The magneto-optical recording medium according to claim 1, wherein said intermediate layer (12) is composed of TbFeCo.
Claim 5
Dependent Claim
52 words
The magneto-optical recording medium (10) according to anyone of claims 1 to 4, wherein an upper limit of an output power of said radiated light is 1.5 mW and said radiated light is moved at speed of 1.2 m/s relative to said magneto-optical recording medium (10) to thereby reproduce the recorded information.
Claim 6
Dependent Claim
148 words
A magneto-optical recording medium (10) having at least a recording layer (13), a reproducing layer (11) and an intermediate layer (12) interposed between said recording and reproducing layers (11, 13), in which said recording layer (13) and said reproducing layer (11) are magnetically coupled by means of said intermediate layer (12) in an area (14) in which a temperature is increased to be higher than a predetermined temperature by the radiation of a light upon reproducing to thereby transfer a recorded information held on said recording layer (13) to said reproducing layer (11) and in which said recorded information is read out from said reproducing layer (11) at its area overlapping an area in which said recorded information is transferred to said reproducing layer (13) of said radiated area (5), characterized in that a Curie temperature of said intermediate layer (12) is selected to be 150°C or more.
Claim 7
Dependent Claim
43 words
The magneto-optical recording medium (10) according to claim 6, wherein said recording layer (13) and said reproducing layer (11) are magnetically coupled by means of said intermediate layer (12) after magnetization directions of said reproducing layer (11) are arranged in a constant direction.
Claim 8
Independent Claim
229 words
An apparatus for recording and/or reproducing a magneto-optical recording medium (10), comprising: means (62) for generating a first channel clock used to write and/or read data in and/or from a first magneto-optical recording medium (10), said first magneto-optical recording medium (10) having a recording layer (13), a reproducing layer (11) and an intermediate layer (12) for magnetically coupling said recording layer (13) and said reproducing layer (11) in a stationary state, in which a magnetic coupling between said recording layer (13) and said reproducing layer (11) is lost in an area (14) in which a temperature is increased to be higher than a predetermined temperature by the radiation of a light upon reproducing and in which a recorded information held on said recording layer (13) is read out from said reproducing layer (11) in the radiated area (5) except the area (14) in which said magnetic coupling is lost; means (62) for generating a second channel clock used to write and/or read data in and/or from a second magneto-optical recording medium (10) in which a recorded information is reproduced by using substantially whole area of said radiated area (5); discriminating means (70) for discriminating said first magneto-optical recording medium (10) and said second magneto-optical recording medium (10); and means (40) for switching said first and second channel clocks in response to a discriminating signal from said discriminating means (70).
Claim 9
Dependent Claim
30 words
The apparatus according to claim 8, wherein an identifying information for discriminating said first and second magneto-optical recording media (10) is recorded in advance on said magneto-optical recording medium (10).
Claim 10
Dependent Claim
25 words
The apparatus according to claim 9, wherein said identifying information is recorded in advance only on either said first or second magneto-optical recording medium (10).
Claim 11
Independent Claim
34 words
The apparatus according to anyone of claims 8 to 10, wherein said first magneto-optical recording medium (10) and said second magneto-optical recording medium (10) are the same in speed relative to a radiated light.
Claim 12
Independent Claim
30 words
The apparatus according to anyone of claims 8 to 11, wherein said first magneto-optical recording medium (10) and said second magneto-optical recording medium (10) are the same in data format.
Claim 13
Independent Claim
53 words
The apparatus according to anyone of claims 8 to 12, wherein an information exclusively used for playback recorded in advance on said first magneto-optical recording medium (10) and an information exclusively used for playback recorded in advance on said second magneto-optical recording medium (10) are reproduced by means of the same channel clock.
Claim 14
Independent Claim
82 words
The apparatus according to anyone of claims 8 to 13, further comprising: a first encoder/decoder (60) for carrying out the encoding and decoding corresponding to a data format of a first magneto-optical recording medium (10); and a second encoder/decoder (60) for carrying out the encoding and decoding corresponding to a data format of said second magneto-optical recording medium (10), wherein said first encoder/decoder (60) and said second encoder/decoder (60) are switched in response to said discriminating signal from said discriminating means (70).
Claim 15
Independent Claim
242 words
An apparatus for recording and/or reproducing a magneto-optical recording medium (10), comprising: means (62) for generating a first channel clock used to write and/or read data in and/or from a first magneto-optical recording medium (10), said first magneto-optical recording medium (10) having at least a recording layer (13), a reproducing layer (11) and an intermediate layer (12) interposed between said recording layer (13) and said reproducing layer (11), in which said recording layer (13) and said reproducing layer (11) are magnetically coupled by means of said intermediate layer (12) in an area (14) in which a temperature is increased to be higher than a predetermined temperature by the radiation of light upon reproducing to thereby transfer a recorded information held on said recording layer (13) to said reproducing layer (11) and in which said recorded information is read out from said reproducing layer (11) at its area overlapping an area to which said recorded information is transferred of said radiated area (5); means (62) for generating a second channel clock used to write and/or read data in and/or from a second magneto-optical recording medium (10) in which a recorded information is reproduced by using substantially whole area of said radiated area (5); discriminating means (70) for discriminating said first magneto-optical recording medium (10) and said second magneto-optical recording medium (10); and means (40) for switching said first and second channel clocks in response to a discriminating signal from said discriminating means (70).
Claim 16
Dependent Claim
32 words
The apparatus according to claim 15, further comprising means (51, 52, 53) for generating an external magnetic field used to arrange magnetization direction of said reproducing layer (11) in a constant direction.
Claim 17
Dependent Claim
31 words
The apparatus according to claim 15 or 16, wherein said magneto-optical recording medium (10) has recorded thereon in advance an identifying information to discriminate said first and second magneto-optical recording media.
Claim 18
Independent Claim
34 words
The apparatus according to anyone of claims 15 to 17, wherein said first magneto-optical recording medium (10) and said second magneto-optical recording medium (10) are the same in speed relative to a radiated light.
References Cited (Backward Citations)
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