Information recording medium
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsKenichi Nishiuchi, Nobuo Akahira, Noboru Yamada, Eiji Ohno
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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.
Claims4
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.
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.
Dependencies are inferred from the claim text.