Abstract: An optical recording medium which comprises a substrate and a recording layer disposed on the substrate, in which the recording layer comprises Ga and Sb, a content of the Sb is 80 atm % to 95 atm % relative to a total content of the Ga and the Sb in the recording layer, and recording and erasing are carried out by a reversible phase change between an amorphous phase and a crystalline phase in the recording layer.

Abstract: An optical recording medium having two recording layer structures which includes a cover substrate, a grooved substrate, a first recording layer structure, an intermediate layer, a separation layer, and a second recording layer structure. In the optical recording medium, the two recording layer structures include a first recording layer structure, and a second recording layer structure between the substrates, the first recording layer structure includes, in this order, a first protective layer, a first recording layer, a second protective layer, a first inorganic layer, the second recording layer structure includes, in this order, a third protective layer, a second recording layer, a forth protective layer, a second inorganic layer, and a ratio of a thickness of the first recording layer structure and a thickness of the intermediate layer is 0.2 to 1.0.

Abstract: A phase-change optical information recording medium in which information can be recorded, erased, and read includes a substrate and a recording layer overlying the substrate. The recording layer achieves a crystal phase and an amorphous phase. The absorptance Ac of the recording layer in the crystal phase against light having a wavelength of from 370 nm to 450 nm is lower than the absorptance Aa of the recording layer in the amorphous phase against the light. Information is recorded on the recording medium with a recording wavelength of from 370 nm to 450 nm at a recording pitch of 0.3 &mgr;m to 0.52 &mgr;m.

Abstract: A sputtering target contains a target material including as constituent elements Ag, In, Te and Sb with the respective atomic percents (atom. %) of &agr;, &bgr;, &ggr; and &dgr; thereof being in the relationship of 0.5≦&agr;<8, 5≦&bgr;≦23, 17≦&ggr;≦38, 32≦&dgr;≦73, &agr;≦&bgr;, and &agr;+&bgr;+&ggr;+&dgr;=100, and a method of producing the above sputtering target is provided. An optical recording medium includes a recording layer containing a phase-change recording material which includes as constituent elements Ag, In, Te and Sb with the respective atomic percents of &agr;, &bgr;, &ggr; and &dgr; thereof being in the relationship of 1≦&agr;<6, 7≦&bgr;≦20, 20≦&ggr;≦35, 35≦&dgr;≦70, and &agr;+&bgr;+&ggr;+&dgr;=100, and is capable of recording and erasing information by utilizing the phase change of the recording material in the recording layer.

Abstract: An optical recording medium configured with a light reflection layer; a first protection layer; a recording layer containing a phase-change material which changes between crystalline and amorphous phases by a light irradiation; a second protection layer; and one of a cover layer and a protective coating layer disposed on a substrate in this order; and in which the light reflection layer is formed of one of an Al alloy and an Ag alloy; the first protection layer has a ZnS—SiO2 mixture layer which contains a mixture of ZnS and SiO2, and a intermediate layer having higher thermal conductivity than the ZnS—SiO2 mixture layer; the intermediate layer is formed on the side of the light reflection layer; the recording layer comprises Ge, Sb, and Te as main elements; and the second protection layer comprises a mixture of ZnS and SiO2.

Abstract: The present invention relates to a phase-change optical information recording medium comprising a recording layer which reversibly phase-changes between the crystalline phase and the amorphous phase by irradiation of a light having a recording wavelength of 390 to 430 nm, and a light transmittance thermally controllable layer showing a light transmittance varying according to temperature, in which the light transmittance increases at a rate of 0.2 to 0.7% /10° C.

Abstract: An input bit sequence with predetermined bit periods T is converted into a corresponding light-emission waveform; and a beam with the thus-obtained light-emission waveform is applied onto a phase-change optical disk so as to record the input bit sequence thereon. The light-emission waveform comprises a heating pulse for heating the recording medium occurring for an interval tw and a cooling pulse for cooling the recording medium occurring for an interval tc, and the intervals tw and tc on the heating/cooling pulses satisfy the following requirement in case the heating/cooling pulses occur alternately with repetition: 1.5T≦tw+tc≦3T.

Abstract: A product for recording information by use of laser light includes a recording layer being able to change between an amorphous state and a crystalline state so as to record information, the recording layer having a thickness falling within a first range defined relative to a wavelength of the laser light, a protection layer having a thickness falling within a second range defined relative to the wavelength of the laser light, a heat releasing layer having a thickness falling within a third range defined relative to the wavelength of the laser light, and a transparent substrate supporting the layers. The first, second, and third ranges are selected such that a phase of the laser light reflected by the amorphous state and a phase of the laser light reflected by the crystalline state have a phase difference larger than a predetermined phase amount.

Abstract: A phase-change optical information recording medium in which information can be recorded, erased, and read includes a substrate and a recording layer overlying the substrate. The recording layer achieves a crystal phase and an amorphous phase. The absorptance Ac of the recording layer in the crystal phase against light having a wavelength of from 370 nm to 450 nm is lower than the absorptance Aa of the recording layer in the amorphous phase against the light. Information is recorded on the recording medium with a recording wavelength of from 370 nm to 450 nm at a recording pitch of 0.3 &mgr;m to 0.52 &mgr;m.

Abstract: A product for recording information by use of laser light includes a recording layer being able to change between an amorphous state and a crystalline state so as to record information, the recording layer having a thickness falling within a first range defined relative to a wavelength of the laser light, a protection layer having a thickness falling within a second range defined relative to the wavelength of the laser light, a heat releasing layer having a thickness falling within a third range defined relative to the wavelength of the laser light, and a transparent substrate supporting the layers. The first, second, and third ranges are selected such that a phase of the laser light reflected by the amorphous state and a phase of the laser light reflected by the crystalline state have a phase difference larger than a predetermined phase amount.

Abstract: A sputtering target contains a target material including as constituent elements Ag, In, Te and Sb with the respective atomic percents (atom. %) of &agr;, &bgr;, &ggr; and &dgr; thereof being in the relationship of 0.5≦&agr;<8, 5≦&bgr;≦23, 17≦&ggr;≦38, 32≦&dgr;≦73, &agr;≦&bgr;, and &agr;+&bgr;+&ggr;+&dgr;=100, and a method of producing the above sputtering target is provided. An optical recording medium includes a recording layer containing a phase-change recording material which includes as constituent elements Ag, In, Te and Sb with the respective atomic percents of &agr;, &bgr;, &ggr; and &dgr; thereof being in the relationship of 1≦&agr;<6, 7≦&bgr;≦20, 20≦&ggr;≦35, 35≦&dgr;≦70, and &agr;+&bgr;+&ggr;+&dgr;=100, and is capable of recording and erasing information by utilizing the phase change of the recording material in the recording layer.

Abstract: A sputtering target contains a target material including as constituent elements Ag, In, Te and Sb with the respective atomic percents (atom. %) of &agr;, &bgr;, &ggr; and &dgr; thereof being in the relationship of 0.5≦&agr;<8, 5≦&bgr;≦23, 17≦&ggr;≦38, 32≦&dgr;≦73, &agr;≦&bgr;, and &agr;+&bgr;+&ggr;+&dgr;=100, and a method of producing the above sputtering target is provided. An optical recording medium includes a recording layer containing a phase-change recording material which includes as constituent elements Ag, In, Te and Sb with the respective atomic percents of &agr;, &bgr;, &ggr; and &dgr; thereof being in the relationship of 1≦&agr;<6, 7≦&bgr;≦20, 20≦&ggr;≦35, 35≦&dgr;≦70, and &agr;+&bgr;+&ggr;+&dgr;=100, and is capable of recording and erasing information by utilizing the phase change of the recording material in the recording layer.

Abstract: An optical information recording medium includes a substrate with guide grooves thereon, a recording layer provided on the substrate, including a recording material of which phase is reversibly changeable from a stable state to a semistable state and vice versa, a heat-resistant dielectric protective layer provided on the recording layer, including a protective material which includes Zn, Si, S and O, and a light reflection and heat dissipation layer provided on the heat-resistant dielectric protective layer.

Abstract: A phase-change optical recording medium has a substrate, and a lower heat-resistant protective layer, a recording layer capable of recording and erasing information by utilizing changes in the phase of a phase-change recording material in the recording layer, an upper heat-resistant protective layer and a light reflecting and heat dissipating layer, which are successively overlaid on the substrate in this order, the recording material including Ag, In, Sb and Te as the main elements, at least one additional element selected from the group (1) consisting of B, C, N, Al, Si and P, and at least one additional element selected from the group (2) consisting of halogen atoms and alkali metal elements.

Abstract: An erasable phase change recording medium includes a transparent substrate, a recording layer of a phase change material provided on the substrate, and a protection layer provided to protect the recording layer on the substrate. Tracks are formed with alternate grooves and lands on the substrate of the recording medium and data is recorded to at least one of the grooves and the lands. The recording medium is configured to have a track pitch between 0.6 .mu.m and 0.8 .mu.m and a groove depth between 0.11.L and 0.18.L where L is a wavelength of a laser beam.

Abstract: A sputtering target contains a target material including as constituent elements Ag, In, Te and Sb with the respective atomic percents (atom. %) of .alpha., .beta., .gamma. and .delta. thereof being in the relationship of 0.5.ltoreq..alpha.<8, 5.ltoreq..beta..ltoreq.23, 17.ltoreq..gamma..ltoreq.38, 32.ltoreq..delta..ltoreq.73, .alpha..ltoreq..beta., and .alpha.+.beta.+.gamma.+.delta.=100, and a method of producing the above sputtering target is provided. An optical recording medium includes a recording layer containing a phase-change recording material which includes as constituent elements Ag, In, Te and Sb with the respective atomic percents of .alpha., .beta., .gamma. and .delta. thereof being in the relationship of 1.ltoreq..alpha.<6, 7.ltoreq..beta..ltoreq.20, 20.ltoreq..gamma..ltoreq.35, 35.ltoreq..delta..ltoreq.70, and .alpha.+.beta.+.gamma.+.delta.=100, and is capable of recording and erasing information by utilizing the phase change of the recording material in the recording layer.