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US 4,647,947 AGranted
Optical protuberant bubble recording medium
AssigneeTokyo Shibaura Denki Kabushiki Kaisha
InventorsYoshikatsu Takeoka, Nobuaki Yasuda
Life of this patent
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Abstract
A disk-shaped optical type recording medium is disclosed which includes a transparent substrate and recording layer formed on the substrate. The recording layer in a single layer, which is made of a material capable of absorbing energy reaching it through the substrate and being locally raised on one surface according to the absorbed heat energy of the laser beam.
Claims17
A record carrier body comprising:
- a substrate;
- and
- an electromagnetic energy absorbing layer formed on the substrate and containing therein elements which are in a gaseous state at a temperature below a predetermined temperature, said layer being provided to store information according to incident electromagnetic radiation thereon, said layer being a single layer which, when a laser beam is exposed thereon, with an intensity of an energy level smaller than a predetermined minimum energy level necessary to form a hole or pit therein, absorbs the radiation energy therein, liberates said elements, and locally raises or bulges the laser beam-exposed area thereof according to the absorbed radiation energy, to store information with the raised area kept as it is, and
- wherein said layer is made of a mixture of a low melting metal selected from the group consisting of tellurium, antimony, tin, bismuth, zinc and lead and said elements comprising ccarbon and hydrogen.
1 more element
A record carrier body used as an optical disk, comprising:
- a disk-shaped transparent substrate of a first thickness to permit a passage of an incident laser beam;
- and
- a recording layer formed on said substrate and having a second thickness smaller than said first thickness of said substrate, said recording layer being made of a single electromagnetic energy absorbing layer containing therein elements which are in a gaseous state at a temperature below a predetermined temperature, said second thickness being selected such that, when the laser beam is exposed thereon with an intensity smaller than a threshold level, wherein said threshold level is a predetermined energy level necessary to form a hole or pit, said layer absorbs said radiation energy, liberates said elements, and locally raises or bulges the laser beam-exposed area thereof according to the absorbed radiation energy to store information with the raised or bulged area kept as it is,
- said reocrding layer being made of a mixture of a low melting metal selected from a group consisting of tellurium, antimony, tin, bismuth, zinc and lead and
- said elements including carbon, hydrogen and at least one element selected from the group consisting of nitrogen, oxygen, phosphorus, iodine, bromine and sulfur.
2 more elements
Dependencies are inferred from the claim text.