EP0136801A2
Expired / Lapsed
EP
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Recording Material
Assignee: Hitachi Ltd
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Filing: 1984-08-22
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Granted: —
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Expires: 2004-08-22
Abstract
Abstract A recording material made of an alloy capable of exhibiting different spectral reflectances at an equal temperature, depending on a heating-cooling cycle to which the alloy is subjected. The alloy can possess in solid state different crystal structures at a first temperature higher than the room temperature and at a second temperature lower than the first temperature but not lower than the room temperature. A part of the surface of the alloy exhibits, as a result of being quenched from the first temperature, a crystal structure which is different from the crystal structure at the second temperature, while the other part possesses the crystal structure at the second temperature, so that these two parts exhibit different spectral reflectances. Using this recording medium, it is possible to record, reproduce and erase information by means of, for example, laser beams.
Inventors
- 👤 Tetsuro Minemura
- 👤 Hisashi Ando
- 👤 Isao Ikuta
- 👤 Yoshiaki Kita
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-27 06:33
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/24; G11B7/241; G11B7/242; G11B7/243; C; C22; C22C; C22C9/00; G11C; G11C11/00; G11C11/02; G11B2007/24302; G11B2007/24308; Y; Y10; Y10S; Y10S430/00; Y10S430/146
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
84 words
A recording material formed from an alloy having in solid state different crystal structures at a first temperature higher than the room temperature and at a second temperature lower than said first temperature but not lower than the room temperature, wherein said alloy has such an alloy composition that at least a part of the surface of said alloy forms, as a result of being quenched from said first temperature, a crystal structure which is different from the crystal structure at said second temperature.
Claim 2
Dependent Claim
84 words
A recording material formed from an alloy having in solid state different crystal structures at a first temperature higher than the room temperature and at a second temperature lower than said first temperature but not lower than the room temperature, wherein said alloy has such an alloy composition that at least a part of the surface of said alloy forms, as a result of being quenched from said first temperature, a crystal structure which is different from the crystal structure at said second temperature.
Claim 3
Dependent Claim
39 words
A recording material according to claim 1, wherein said alloy consists of at least one element selected from the group Ib and at least one element selected from the groups IIb, IIIb, IVb and Vb in the periodic table.
Claim 4
Dependent Claim
34 words
A recording material according to claim 2, wherein said alloy contains an intermetallic compound of said element selected from the group Ib and said element selected from the groups IIb, IIIb, IVb and Vb.
Claim 5
Dependent Claim
24 words
A recording material according to any one of claims 1 to 3, wherein said first temperature is higher than the solid phase transformation temperature.
Claim 6
Dependent Claim
54 words
A recording material according to any one of claims 1 to 4, wherein the difference between the spectral reflectance of the alloy having the crystal structure formed by said quenching and the spectral reflectance of the same alloy having the crystal structure at said first temperature formed by non-quenching is not smaller than 5%.
Claim 7
Dependent Claim
34 words
A recording material according to any one of claims 1 to 5, wherein the spectral reflectance of said alloy is not smaller than 10% at the wavelength region of between 400 and 1000 nm.
Claim 8
Dependent Claim
21 words
7 . A recording material according to any one of claims 1 to 6, wherein said alloy is a non-bulk material.
Claim 9
Dependent Claim
26 words
A recording material according to any one of claims 1 to 7, wherein said alloy has a crystal grain size of not greater than 0.1 µm.
Claim 10
Dependent Claim
25 words
A recording material according to claim 7, wherein said alloy has one of the forms of a thin film, foil, strip, powder and thin wire.
Claim 11
Dependent Claim
29 words
A recording material according to claim 9, wherein said material is a non-bulk formed by quenching a melt of said alloy or by quenching a gas of said alloy.
Claim 12
Dependent Claim
44 words
A recording material according to claim 10, wherein said material is a foil or a thin wire formed by pouring said melt onto the peripheral surface of a roll made of a material having a high heat conductivity and rotating at a high speed.
Claim 13
Dependent Claim
23 words
A recording material according to claim 10, wherein said material is a thin film of said alloy deposited by vacuum evaporation or sputtering.
Claim 14
Dependent Claim
33 words
A recording material according to claim 10, wherein said material is made of powder of said alloy formed by atomizing, quenching and solidifying said melt by a cooling medium of liquid or gas.
Claim 15
Dependent Claim
95 words
A spectral reflectance changeable alloy having in solid state different crystal structures at a-first temperature higher than the room temperature and at a second temperature lower than said first temperature but not lower than the room temperature, wherein a part of the surface of said alloy possesses, as a result of being super-cooled from said first temperature, a crystal structure which is different from the crystal structure at said second temperature, while other part possesses the crystal structure at said second temperature thereby exhibiting a spectral reflectance different from that of said super-cooled crystal structure.
Claim 16
Dependent Claim
95 words
A spectral reflectance changeable alloy having in solid state different crystal structures at a-first temperature higher than the room temperature and at a second temperature lower than said first temperature but not lower than the room temperature, wherein a part of the surface of said alloy possesses, as a result of being super-cooled from said first temperature, a crystal structure which is different from the crystal structure at said second temperature, while other part possesses the crystal structure at said second temperature thereby exhibiting a spectral reflectance different from that of said super-cooled crystal structure.
Claim 17
Dependent Claim
41 words
A spectral reflectance changeable alloy according to claim 14, wherein said alloy consists of at least one element selected from the group Ib and at least one element selected from the groups IIb, IIIb, IVb and Vb in the periodic table.
Claim 18
Dependent Claim
36 words
A spectral reflectance changeable alloy according to claim 15, wherein said alloy contains an intermetallic compound of said element selected from the group Ib and said element selected from the groups IIb, IIIb, IVb and Vb.
Claim 19
Dependent Claim
25 words
A spectral reflectance changeable alloy according to any one of claims 14 to 16 wherein said first temperature is higher than the eutectoid transformation temperature.
Claim 20
Dependent Claim
56 words
A spectral reflectance changeable alloy according to any one of claims 14 to 17, wherein the difference between the spectral reflectance of the alloy having the crystal structure formed by said quenching and the spectral reflectance of the same alloy having the crystal structure at said second temperature formed by non-quenching is not smaller than 5%.
Claim 21
Dependent Claim
36 words
A spectral reflectance changeable alloy according to any one of claims 14 to 18, wherein the spectral reflectance of said alloy is not smaller than 10% at the wavelength region of between 400 and 800 nm.
Claim 22
Dependent Claim
21 words
A spectral reflectance changeable alloy according to any one of claims 14 to 19, wherein said alloy is a non-bulk material.
Claim 23
Dependent Claim
28 words
A spectral reflectance changeable alloy according to any one of claims 14 to 20, wherein said alloy has a crystal grain size of not greater than 0.1 µm.
Claim 24
Dependent Claim
27 words
A spectral reflectance changeable alloy according to claim 20, wherein said alloy has one of the forms of a thin film, foil, strip, powder and thin wire.
Claim 25
Independent Claim
112 words
A method of producing a spectral reflectance changeable alloy comprising: preparing an alloy possessing in solid state different crystal structures at a first temperature higher than the room temperature and at a second temperature lower than said first temperature but not lower than the room temperature; and forming, in a part of the surface of said alloy, a region having a crystal structure which is different from the crystal structure at said second temperature by super-cooling said part from said first temperature; whereby the region formed by said super-cooling exhibits a spectral reflectance which is different from the spectral reflectance exhibited by the region having said crystal structure at said second temperature.
Claim 26
Independent Claim
112 words
A method of producing a spectral reflectance changeable alloy comprising: preparing an alloy possessing in solid state different crystal structures at a first temperature higher than the room temperature and at a second temperature lower than said first temperature but not lower than the room temperature; and forming, in a part of the surface of said alloy, a region having a crystal structure which is different from the crystal structure at said second temperature by super-cooling said part from said first temperature; whereby the region formed by said super-cooling exhibits a spectral reflectance which is different from the spectral reflectance exhibited by the region having said crystal structure at said second temperature.
Claim 27
Independent Claim
132 words
A method of producing a spectral reflectance changeable alloy comprising: preparing an alloy possessing in solid state different crystal structures at a first temeperature higher than the room temperature and at a second temperature lower than said first temperature but not lower than the room temperature; forming, over the entire surface of said alloy, a crystal structure which is different from the crystal structure at said second temperature by super-cooling said entire surface from said first temperature; and heating a part of said surface of said alloy to said second temperature to form a region having the crystal structure at said second temperature; whereby the region formed by said super-cooling exhibits a spectral'reflectance which is different from the spectral reflectance exhibited by the region having said crystal structure at said second temperature.
Claim 28
Independent Claim
132 words
A method of producing a spectral reflectance changeable alloy comprising: preparing an alloy possessing in solid state different crystal structures at a first temeperature higher than the room temperature and at a second temperature lower than said first temperature but not lower than the room temperature; forming, over the entire surface of said alloy, a crystal structure which is different from the crystal structure at said second temperature by super-cooling said entire surface from said first temperature; and heating a part of said surface of said alloy to said second temperature to form a region having the crystal structure at said second temperature; whereby the region formed by said super-cooling exhibits a spectral'reflectance which is different from the spectral reflectance exhibited by the region having said crystal structure at said second temperature.
References Cited (Backward Citations)
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