Abstract: An optical information recording method including: irradiating a recording medium with laser light, wherein 0 signals having width nT are recorded or rewritten using continuous laser light having a power level Pe, and 1 signals having width nT are recorded or rewritten using a light pulse train having a first pulse portion fp having power Pw and width xT (T: clock time), a multi-pulse portion mp in which a number (n−n′) of high level pulses each having power Pw′ and width yT, and, if (n−n′)>1, a low level pulse which has power Pb and width (1−y)T are applied, and an end pulse portion ep having power Pb′ and width zT, wherein n and n′ are a positive integer (n>n′), and wherein each of Pw and Pw′ is greater than Pe, Pe is greater than each of Pb and Pb′, and at least one of x, y and z is in a range as follows: 0.35≦x≦0.75, 0.30≦y≦0.55, 0.35≦z≦0.70.

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: 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 capable of recording information therein, reproducing recorded information therefrom, rewriting recorded information, and erasing recorded information therefrom, which phase-change optical information recording medium is provided with a recording layer containing therein a phase-change recording material including Ge, Ga, Sb, Te, and one element selected from the group consisting of Mg and Ca, which recording material is capable of performing a reversible phase transition from a noncrystalline phase to a crystalline phase and vice verse with the application of an electromagnetic wave thereto.

Abstract: An optical information recording medium includes a first dielectric protective layer, a recording layer provided on the first dielectric protective layer, including a material represented by a chemical formula of Ag&agr;In&bgr;Sb&ggr;Te&dgr;, wherein &agr;, &bgr;, &ggr; and &dgr; respectively represent an atomic percent of Ag, an atomic percent of In, an atomic percent of Sb, and an atomic percent of Te, and satisfy the conditions of: 1≦&agr;<10, 1<&bgr;≦20, 35≦&ggr;≦70, 20≦&dgr;≦35, &agr;+&bgr;+&ggr;+&dgr;=100, 4&bgr;−&dgr;≦0, &ggr;−2&dgr;≧0, and &ggr;−8&agr;≧0, a second dielectric protective layer provided on the recording layer, and a light reflection and heat dissipation layer provided on the second dielectric protective layer.

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 &dgr;repeat/&dgr;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 producing the optical recording medium, and a method of writing information in the optical recording medium, reading written information therefrom and rewriting written information thereare are proposed.

Abstract: An optical information recording medium includes a first dielectric protective layer, a recording layer provided on the first dielectric protective layer, including a material represented by a chemical formula of Ag&agr;In&bgr;Sb&ggr;Te&dgr;, wherein &agr;, &bgr;, &ggr; and &dgr; respectively represent an atomic percent of Ag, an atomic percent of In, an atomic percent of Sb, and an atomic percent of Te, and satisfy the conditions of: 1≦&agr;<10, 1<&bgr;≦20, 35≦&ggr;≦70, 20≦&dgr;≦35, &agr;+&bgr;+&ggr;+&dgr;=100, 4&bgr;−&dgr;≦0, &ggr;−2&dgr;≧0, and &ggr;−8&agr;≧0, a second dielectric protective layer provided on the recording layer, and a light reflection and heat dissipation layer provided on the second 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: A three-dimensional magnetic memory medium which comprises a substrate, a plurality of magnetic layers and a plurality of nonmagnetic layers. The magnetic layers and the nonmagnetic layers are alternately stacked one above the other on the substrate. Each magnetic layer comprises a transfer area, wherein assuming that n is a positive even whole number, the (n-1)th magnetic layer (the 3rd layer, the 5th layer, the 7th layer, . . .) has a transfer pattern different from that of the nth magnetic layer (the 2nd layer, the 4th layer, the 6th layer, . . .). An uppermost magnetic layer is used as a signal writing area and as a signal reading area. A position corresponding to a signal "1" and a position corresponding to a signal "0" are arranged in the signal writing area at a position superposed on a position of "1" and on a position of "0" in a transfer pattern of the (n-1)th magnetic layer, respectively.