Abstract: The present invention relates to an recording method for a multi-layered optical recording medium including M phase change recording layers, with M?2. The method comprises recording a mark in a Kth one of said recording layers by using a laser to irradiate the Kth recording layer using a recording pulse train including a plurality of laser beam pulses. The recording pulse train for the Kth recording layer has a cycle of t(K)[T], the 1st recording layer is the recording layer closest the laser beam, and the Mth recording layer is the recording layer furthest from the laser beam, T is a clock cycle. The following relationship is satisfied: t(1)<t(M), and the cycle of recording pulse train does not decrease from one recording layer to the next recording layer in the direction in which the laser beam irradiates.

Abstract: An optical information recording medium is provided. This medium at least stores information that indicates a maximum recording linear velocity Vh. The medium comprises a substrate having a concentric circular guide groove. This guide grove has land portions and groves portions. At least a phase change type recording layer is formed on the substrate. The recording layer has such a composition and thickness that a dislocation linear velocity V satisfies the relation V?Vh×0.85.

Abstract: It is an object of the present invention to provide a phase-change information recording medium, and the like, which is easy to perform initial crystallization, exhibits good recording sensitivity at a linear velocity as high as 10 double speeds or more with as much capacity as DVD-ROM, is capable of overwrite recording and has good storage reliability. For this purpose, the phase-change information recording medium comprises a substrate and at least a first protective layer, a phase-change recording layer, a second protective layer, and a reflective layer disposed on the substrate in one of this sequence and reverse sequence wherein the phase-change recording layer comprises a composition expressed by Sn?Sb?Ga?Ge?Te??X? (In this regard, X represents at lease one element selected from Ag, Zn, In and Cu. ?, ?, ?, ?, ? and ? represent composition ratio (atomic percent) of each element and are expressed as 5???25, 40???91, 2???20, 2???20, 0???10, 0???10 and ?+?+?+?+?+?=100).

Abstract: To provide an optical recording medium and the like that is adapted to higher density and higher speed recording of 8 times or more than that of DVD (about 28 m/sec or more) and that exhibits superior repeating and reservation properties. An optical recording medium is provided that comprises a substrate, and a recording layer, wherein at least one of recording, reproducing, erasing, and rewriting of information is carried out by means of reversible phase changes at marks on the recording layer, the reversible phase changes at marks are induced between crystalline and amorphous states by laser irradiation, the length of the respective marks is 0.4 ?m or less in the traveling direction of the laser irradiation, and the recording layer has a composition expressed by the formula: In?Sb?, wherein ? and ? are atomic percent of the respective elements; 0.73??/(?+?)?0.

Abstract: An optical recording medium including a recording layer which includes a reversible phase-change recording material, the recording layer being capable of writing information therein, reading written information therefrom, and rewriting written information by utilizing the reversible phase change of the phase-change recording material, wherein when a recording mark formed in the recording layer is repeatedly read 5000 times, using a continuous wave laser beam having such an intensity Pr that satisfies the condition of 1.1?R?2.0, in which R is ?repeat/?1 as defined in the specification, the optical recording medium satisfies a relationship of d1>dow as defined in the specification. The phase-change recording material, a method of producing the optical recording medium, and a method of writing information in the optical recording medium, reading written information therefrom and rewriting written information therein are proposed.

Abstract: An optical recording medium has a phase-change recording layer containing Sb and Te as essential elements therefor, to which is added at least one element selected from the group consisting of Ag, Au, Cu, Zn, B, Al, Ga, In, Si, Ge, Sn, Pb, N, P, Bi, La, Ce, Gd, and Tb, the recording layer being capable of assuming an amorphous phase changed from a crystalline phase by the application of a laser beam thereto, thereby optically recording information. Recording marks are formed in the recording medium by converting a light emission wave of laser beam into a recording pulse train comprising a plurality of on-pulses and off-pulses, with a recording frequency being continuously changed corresponding to the location of each of the recording marks in the radial direction of said recording medium. A recording apparatus has laser beam driving circuit means, signal generation means, and signal transmission means for achieving the above recording method.

Abstract: A sputtering target contains a target material including as constituent elements Ag, In, Te and Sb with the respective atomic percents (atom. %) of ?, ?, ? and ? thereof being in the relationship of 0.5??<8, 5???23, 17???38, 32???73, ???, and ?+?+?+?=100, and a method of producing the above sputtering target is provided.

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: A recording method forms recording marks according to a mark length modulation by irradiating a pulse-shaped light beam with respect to a crystallized phase change recording layer of a phase change type optical recording medium which comprises at least the phase change recording layer and a reflection layer on a substrate. The recording method irradiates a light beam formed by a single recording pulse when forming a recording mark having a size less than or equal to a predetermined size N, where the predetermined size N is set with reference to a reference size which is sum of a beam spot diameter of the light beam and a distance traveled by the light beam within a time amounting to a sum of rising and falling time constants of a light beam power, and irradiates a light beam formed by a plurality of recording pulses when forming a recording mark having a size greater than the predetermined size N.

Abstract: The present invention relates to an recording method for a multi-layered optical recording medium including M phase change recording layers, with M?2. The method comprises recording a mark in a Kth one of said recording layers by using a laser to irradiate the Kth recording layer using a recording pulse train including a plurality of laser beam pulses. The recording pulse train for the Kth recording layer has a cycle of t(K)[T], the 1st recording layer is the recording layer closest the laser beam, and the Mth recording layer is the recording layer furthest from the laser beam, T is a clock cycle. The the following relationship is satisfied: t(1)<t(M), and the cycle of recording pulse train does not decrease from one recording layer to the next recording layer in the direction in which the laser beam irradiates.

Abstract: To provide an optical recording medium and the like that is adapted to higher density and higher speed recording of 8 times or more than that of DVD (about 28 m/sec or more) and that exhibits superior repeating and reservation properties. An optical recording medium is provided that comprises a substrate, and a recording layer, wherein at least one of recording, reproducing, erasing, and rewriting of information is carried out by means of reversible phase changes at marks on the recording layer, the reversible phase changes at marks are induced between crystalline and amorphous states by laser irradiation, the length of the respective marks is 0.4 ?m or less in the traveling direction of the laser irradiation, and the recording layer has a composition expressed by the formula: In?Sb?, wherein ? and ? are atomic percent of the respective elements; 0.73??/(?+?)?0.

Abstract: An optical recording medium has a phase-change recording layer containing Sb and Te as essential elements therefor, to which is added at least one element selected from the group consisting of Ag, Au, Cu, Zn, B, Al, Ga, In, Si, Ge, Sn, Pb, N, P, Bi, La, Ce, Gd, and Tb, the recording layer being capable of assuming an amorphous phase changed from a crystalline phase by the application of a laser beam thereto, thereby optically recording information. Recording marks are formed in the recording medium by converting a light emission wave of laser beam into a recording pulse train comprising a plurality of on-pulses and off-pulses, with a recording frequency being continuously changed corresponding to the location of each of the recording marks in the radial direction of said recording medium. A recording apparatus has laser beam driving circuit means, signal generation means, and signal transmission means for achieving the above recording method.

Abstract: An optical recording medium has a phase-change recording layer containing Sb and Te as essential elements therefor, to which is added at least one element selected from the group consisting of Ag, Au, Cu, Zn, B, Al, Ga, In, Si, Ge, Sn, Pb, N, P, Bi, La, Ce, Gd, and Tb, the recording layer being capable of assuming an amorphous phase changed from a crystalline phase by the application of a laser beam thereto, thereby optically recording information. Recording marks are formed in the recording medium by converting a light emission wave of laser beam into a recording pulse train comprising a plurality of on-pulses and off-pulses, with a recording frequency being continuously changed corresponding to the location of each of the recording marks in the radial direction of said recording medium. A recording apparatus has laser beam driving circuit means, signal generation means, and signal transmission means for achieving the above recording method.

Abstract: An optical recording medium including a recording layer which includes a reversible phase-change recording material, the recording layer being capable of writing information therein, reading written information therefrom, and rewriting written information by utilizing the reversible phase change of the phase-change recording material, wherein when a recording mark formed in the recording layer is repeatedly read 5000 times, using a continuous wave laser beam having such an intensity Pr that satisfies the condition of 1.1?R?2.0, in which R is ?repeat/?1 as defined in the specification, the optical recording medium satisfies a relationship of d1>dow as defined in the specification. The phase-change recording material, a method of producing the optical recording medium, and a method of writing information in the optical recording medium, reading written information therefrom and rewriting written information therein are proposed.

Abstract: An information recording method including irradiating a phase change recording layer of an optical recording medium with either a multi-pulse laser light train having a recording power of Pw or laser light having an erasing power Pe to record a mark having a length nT in the recording layer, wherein n is an integer of from 3 to 14 and T represents a clock cycle, wherein the multi-pulse laser light train has a constitution such that a heating pulse and a cooling pulse are alternated and the number of heating pulses and the number of cooling pulses each increases by 1 when n increases by 2, and wherein when n is from 6 to 14, the last heating pulse and last cooling pulse have a pulse width of from 0.5T to 0.9T and from 0.7T to 1.5T, respectively.

Abstract: It is an object of the present invention to provide a phase-change information recording medium, and the like, which is easy to perform initial crystallization, exhibits good recording sensitivity at a linear velocity as high as 10 double speeds or more with as much capacity as DVD-ROM, is capable of overwrite recording and has good storage reliability. For this purpose, the phase-change information recording medium comprises a substrate and at least a first protective layer, a phase-change recording layer, a second protective layer, and a reflective layer disposed on the substrate in one of this sequence and reverse sequence wherein the phase-change recording layer comprises a composition expressed by Sn?Sb?Ga?Ge?Te?X? (In this regard, X represents at lease one element selected from Ag, Zn, In and Cu. ?, ?, ?, ?, ? and ? represent composition ratio (atomic percent) of each element and are expressed as 5???25, 40???91, 2???20, 2???20, 0???10, 0???10 and ?+?+?+?+?+?=100).

Abstract: An information recording method including irradiating a phase change recording layer of an optical recording medium with either a multi-pulse laser light train having a recording power of Pw or laser light having an erasing power Pe to record a mark having a length nT in the recording layer, wherein n is an integer of from 3 to 14 and T represents a clock cycle, wherein the multi-pulse laser light train has a constitution such that a heating pulse and a cooling pulse are alternated and the number of heating pulses and the number of cooling pulses each increases by 1 when n increases by 2, and wherein when n is from 6 to 14, the last heating pulse and last cooling pulse have a pulse width of from 0.5T to 0.9T and from 0.7T to 1.5T, respectively.

Abstract: An information recording method including irradiating a phase change recording layer of an optical recording medium with either a multi-pulse laser light train having a recording power of Pw or laser light having an erasing power Pe to record a mark having a length nT in the recording layer, wherein n is an integer of from 3 to 14 and T represents a clock cycle, wherein the multi-pulse laser light train has a constitution such that a heating pulse and a cooling pulse are alternated and the number of heating pulses and the number of cooling pulses each increases by 1 when n increases by 2, and wherein when n is from 6 to 14, the last heating pulse and last cooling pulse have a pulse width of from 0.5T to 0.9T and from 0.7T to 1.5T, respectively.

Abstract: The object of the present invention is to provide an optical recording medium which can respond to high-density and high recording linear velocity with recording linear velocity at 1.0× to 16× or more (recording linear velocity=approx. 3.5 m/s to 56 m/s or more), and a method and an apparatus for the optical recording and reproducing. Thus, the present invention provides an optical recording medium comprising a substrate and at least a recording layer and a reflective layer disposed on the substrate, in which any one of recording, reproducing, erasing, and rewriting of information is enabled by irradiating laser beam to the recording layer to induce a reversible phase change on the recording layer in which the reflectance (Rg) of the non-recorded portion in the case of the recording layer comprising Zn, Sn, and Sb and the laser beam wavelength being within the range of 650 nm to 665 nm is 12% to 30%.

Abstract: An optical recording medium has a phase-change recording layer containing Sb and Te as essential elements therefor, to which is added at least one element selected from the group consisting of Ag, Au, Cu, Zn, B, Al, Ga, In, Si, Ge, Sn, Pb, N, P, Bi, La, Ce, Gd, and Tb, the recording layer being capable of assuming an amorphous phase changed from a crystalline phase by the application of a laser beam thereto, thereby optically recording information. Recording marks are formed in the recording medium by converting a light emission wave of laser beam into a recording pulse train comprising a plurality of on-pulses and off-pulses, with a recording frequency being continuously changed corresponding to the location of each of the recording marks in the radial direction of said recording medium. A recording apparatus has laser beam driving circuit means, signal generation means, and signal transmission means for achieving the above recording method.