Optical information recording medium
AssigneeOlympus Optical Co., Ltd.
InventorsToshiyuki Kanno, Yasuji Nagata, Naoyuki Ueno
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Abstract
An erasable optical information recording medium has a transparent substrate, and a recording layer supported by the substrate. The recording layer includes a thin film of at least one polydiacetylene having side chains. The polydiacetylene is capable of undergoing a reversible planar-nonplanar transition of the main chain structure of the polydiacetylene due to a conformational change of the side chains produced by irradiation of light. When the recording layer is irradiated with light, the reversible planar-nonplanar transition occurs at the irradiated portions to cause a corresponding change of optical properties of the recording layer, thereby recording information thereinto and erasing information therefrom.
Claims19
An erasable optical information recording medium comprising:
- a transparent substrate;
- and
- a recording layer supported by said substrate and comprising a thin film comprising at least one polydiacetylene with side chains, said polydiacetylene being capable of undergoing a reversible planar-nonplanar transition of the main chain structure of said polydiacetylene due to a conformational change of said side chains produced by irradiation of light, and having a repeating unit derived from a diacetylene monomer of the formula:
- Ra--C.tbd.C--C.tbd.C--Rb
- where Ra and Rb are respectively -X-Y-Z, wherein X is a spacer group --(CH.sub.2).sub.n --, --(C.sub.m H.sub.2m--2)--, --(C.sub.m H.sub.2m--4)--, --(C.sub.p H.sub.2p O)--, or --(C.sub.p H.sub.2p--2 O)--, n is an integer equal to 1 or more, m is an integer from 2 to 12, and p is an integer from 1 to 12;
- Y is a bivalent functional group capable of forming hydrogen bonds, and comprising a urethane bond, an amide bond, and imide bond or an amidoimide bond;
- and
- Z is a terminal group selected from the group consisting of a straight chain alkyl group, a straight chain unsaturated hydrocarbon group comprising a double bond, a straight chain unsaturated hydrocarbon group comprising a triple bond, an aromatic hydrocarbon group comprising a benzene ring and an aromatic hydrocarbon group comprising a naphthalene ring, said terminal group being unsubstituted or substituted by a substitutent selected from the group consisting of a cyano, hydroxyl, halogen and nitro group,
- whereby said recording layer undergoes said reversible planar-nonplanar transition at portions thereof which are irradiated with light to cause a corresponding change of optical properties thereof, thereby recording information thereinto and erasing information therefrom, and,
- whereby reading the recorded information is effected by detecting the change of reflectance, refractive index or transmittance of the recording layer.
An erasable optical information recording medium comprising:
- a transparent substrate;
- and
- a recording layer supported by said substrate and comprising a thin film comprising at least one polydiacetylene with side chains comprising therein an intervening bivalent functional group capable of forming hydrogen bonds therebetween, said polydiacetylene being capable of undergoing a reversible planar-nonplanar transition of the main chain structure of said polydiacetylene due to a conformational change of said side chains produced by irradiation of light,
- whereby said recording layer undergoes said reversible planar-nonplanar transition at portions thereof which are irradiated with light to cause a corresponding change of optical properties thereof, thereby recording information thereinto and erasing information therefrom, and
- whereby reading the recorded information is effected by detecting the change of reflectance, refractive index or transmittance of the recording layer.
Dependencies are inferred from the claim text.