Patent US4313703A successfully refreshed from Google Patents.
Patent US4908835A successfully refreshed from Google Patents.
US4908835A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Information recording medium
Assignee: Panasonic Holdings Corp
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Filing: 1989-06-29
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Granted: 1990-03-13
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Expires: 2009-06-29
Abstract
Abstract A method of measuring reliability of an information recording medium which comprises an information recording thin film. The method comprises the steps of heating said film at least once to its melting point, rapidly cooling said film after heating, measuring a transition temperature of said film after cooling, and comparing said transition temperature with a predetermined reference temperature.
Inventors
- 👤 Kenichi Nishiuchi
- 👤 Nobuo Akahira
- 👤 Noboru Yamada
- 👤 Eiji Ohno
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 16:42
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/24; G11B7/241; G11B7/242; G11B7/243; G11B7/2433; G11B7/002; G11B7/0037; G11B7/00375; G11B7/004; G11B7/0045; G11B7/00455; G11B2007/24302; G11B2007/24308; G11B2007/2431; G11B2007/24312; G11B2007/24316; G11B2007/24318; G11B2007/2432; G11B7/252; G11B7/253; G11B7/2533; G11B7/2535
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
106 words
A method of measuring reliability of an information recording medium which comprises an information recording thin film which is formed by a substance having a state of high optical density when it is heated substantially to its darkening temperature and thereafter is slowly cooled and a state of low optical density when it is heated substantially to said melting point and thereafter is rapidly cooled, which method comprises the steps of: heating said film at least once to its melting point, rapidly cooling said film after heating, measuring a transition temperature of said film after cooling, and comparing said transition temperature with a predetermined reference temperature.
Claim 2
Independent Claim
106 words
A method of measuring reliability of an information recording medium which comprises an information recording thin film which is formed by a substance having a state of high optical density when it is heated substantially to its darkening temperature and thereafter is slowly cooled and a state of low optical density when it is heated substantially to said melting point and thereafter is rapidly cooled, which method comprises the steps of: heating said film at least once to its melting point, rapidly cooling said film after heating, measuring a transition temperature of said film after cooling, and comparing said transition temperature with a predetermined reference temperature.
Claim 3
Dependent Claim
51 words
A method of measuring reliability of an information recording medium in accordance with claim 1, wherein said heating step is accomplished by irradiation of a pulsed laser light of a narrow pulse-width which is focused on said information recording thin film, and termination of said irradiation initiates said rapidly cooling step.
Claim 4
Dependent Claim
49 words
A method of measuring reliability of an information recording medium in accordance with claim 1, wherein measurement of said transition temperature comprises the steps of: heating said information recording film under a constant temperature-rise-rate, and measuring continuously the optical density of said information recording film during said heating step.
Claim 5
Independent Claim
148 words
A method of measuring reliability of an information recording medium which comprises an information recording thin film which is formed by a substance having a state of high optical density when it is heated substantially to its darkening temperature and thereafter is slowly cooled and a state of low optical density when it is heated substantially to said melting point and thereafter is rapidly cooled, which method comprises the steps of: annealing said film by heating to a temperature which is lower than said melting point for a predetermined time period for changing a low optical density state of said film to a high optical density state, heating a part of said film at least once to its melting point, rapidly cooling said part of said film after heating, measuring a transition temperature of said film after cooling, and comparing said transition temperature with a predetermined reference temperature.
Claim 6
Independent Claim
148 words
A method of measuring reliability of an information recording medium which comprises an information recording thin film which is formed by a substance having a state of high optical density when it is heated substantially to its darkening temperature and thereafter is slowly cooled and a state of low optical density when it is heated substantially to said melting point and thereafter is rapidly cooled, which method comprises the steps of: annealing said film by heating to a temperature which is lower than said melting point for a predetermined time period for changing a low optical density state of said film to a high optical density state, heating a part of said film at least once to its melting point, rapidly cooling said part of said film after heating, measuring a transition temperature of said film after cooling, and comparing said transition temperature with a predetermined reference temperature.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1993-03-12 | 1993-09-11 | 1994-03-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-03-12 | 1997-09-11 | 1998-03-13 | $3760.00 | Window Closed / Lapsed |
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