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 ?m to 0.52 ?m.

Abstract: An optical recording medium wherein a laser beam at a wavelength ? is irradiated and recording and reproducing of information are performed by optical power modulation of binary or more, and when the refraction index of the first substrate being n1, the refraction index of the intermediate layer being n2, the groove depth, the groove width and the track pitch of the first information layer being d1, w1 and p1 respectively and the groove depth, the groove width and the track pitch of the second information layer being d2, w2 and p2 respectively, the following conditions are satisfied. 4?/16n1?d1?7?/16n1 ?/16n2?d2?3?/16n2 or 4?/16n2?d2?7?/16n2 0.2?w1/p1?0.55 0.2?w2/p2?0.

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 optical information recording medium comprising a substrate, recording layer and reflecting layer, characterized in that a layer containing a mixture of carbide and oxide is disposed over a surface of the reflecting layer which faces to the recording layer. The carbide is a carbide of at least one metal selected from Ti, Zr, V, Nb, Ta, Cr, Mo and W, and the oxide is an oxide of at least one metal selected from Ti, Zr, V, Nb, Ta, Cr, Mo and W.

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: An optical information recording medium comprising a substrate, recording layer and reflecting layer, characterized in that a layer containing a mixture of carbide and oxide is disposed over a surface of the reflecting layer which faces to the recording layer. The carbide is a carbide of at least one metal selected from Ti, Zr, V, Nb, Ta, Cr, Mo and W, and the oxide is an oxide of at least one metal selected from Ti, Zr, V, Nb, Ta, Cr, Mo and W.

Abstract: The present invention is a recording method for optical recording medium forms a few types of amorphous mark vary from at least any one from length and area upon repeated irradiation by a recording power (Pw) light and a cooling power (Pb) light to an information layer comprising a phase-changing recording layer of the optical recording medium, and records information and forms a crystal space upon irradiation of an erasing power (Pe) light, wherein the recording power (Pw) light, the cooling power (Pb) light, and the erasing power (Pe) light satisfying a relation of the following equation Pw>Pe>Pb, and in the case of forming at least one type of amorphous mark upon irradiation by a cooling controlling power (Pm) light to in between the recording power (Pw) light and cooling power (Pb) light, wherein the recording power (Pw) light, cooling power (Pb) light , and cooling controlling power (Pm) light satisfying a relation of the following equation Pw>Pm>Pb.

Abstract: The object of the present invention is to provide an optical recording medium which comprises a substrate, and a first information layer and a second information layer disposed on the substrate, and an intermediate layer disposed between the first information layer and the second information layer, wherein any one of recording and reproducing is performed in the first information layer and the second information layer by irradiating a laser beam from the first information layer side, the second information layer comprises a protective layer, a second dye layer which comprises an organic dye, an oxidized layer, and a reflective layer in this order from the laser beam irradiation side, and the oxidized layer comprises an oxide which is a material constituting the reflective layer.

Abstract: An optical recording medium including a substrate, a bottom protective layer located overlying the substrate, an optical recording layer located overlying the bottom protective layer, a top protective layer located overlying the optical recording layer, an intermediate layer located overlying the top protective layer, comprising at least one element (M) selected from the group consisting of Ti, Nb and Ta, and carbon, an optical reflective layer comprising Ag in an amount not less than 95 atomic %, located overlying the intermediate layer. The optical recording medium is recordable even in at least one of the following recording conditions (1) to (3): (1) when a recording time for a shortest recording mark is not greater than 34 ns; (2) when a recording time of a channel bit length is not greater than 11 ns; and (3) when a recording linear velocity is not less than 11 m/s.

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: The object of the present invention is to provide a two-layered optical recording medium using dye layers for a recording layer which triggers no jitter noise and the like against not only a red laser beam but also against low-power output laser beam such as a blue laser beam, has high archival properties, and is capable of high-density recording, and a method and an apparatus for the optical recording and reproducing. Thus, the optical recording medium comprises a substrate, and a first information layer, and a second information layer disposed on the substrate through an intermediate layer to perform recording and reproducing on the first information layer and the second information layer respectively by irradiating laser beam from the first information layer side.

Abstract: The object of the present invention is to provide a multilayer phase-change information recording medium comprises a substrate, and N layers of information layer (N represents an integral number of 2 or more), and each of the information layers comprises at least a recording layer in which information is recorded by irradiating laser beam to induce a phase change between crystalline phase and amorphous phase. The present invention is characterized in that when the information layer is disposed so that a first information layer, a second information layer, a third information layer . . .

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 ?m to 0.52 ?m.

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 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 multilayer phase change information recording medium including plural information layers containing at least a first information layer and a last information layer, each of which includes a recording layer in which information is recorded utilizing a phase change between a crystalline phase and an amorphous phase. At least one of the plural information layers other than the last information layer includes a first lower protective layer, a first recording layer located overlying the lower protective layer, a first upper protective layer located overlying the first recording layer, a first reflective layer located overlying the first upper protective layer, and a heat diffusion layer located overlying the first reflective layer and which mainly contains In, Zn and O.

Abstract: An optical information recording medium comprising a substrate, recording layer and reflecting layer, characterized in that a layer containing a mixture of carbide and oxide is disposed over a surface of the reflecting layer which faces to the recording layer. The carbide is a carbide of at least one metal selected from Ti, Zr, V, Nb, Ta, Cr, Mo and W, and the oxide is an oxide of at least one metal selected from Ti, Zr, V, Nb, Ta, Cr, Mo and W.

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 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.