Abstract: An optical information recording medium of the present invention includes at least one information layer. The information layer includes a first protective film, a first interface film, a recording film having the optical characteristics that are changed reversibly by laser beam irradiation, a second interface film, a second protective film, and a reflective film, present in the indicated order from the laser beam incident side. The first interface film includes an oxide of at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, and Si. The second interface film includes carbon or a carbide of at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, and Si.

Abstract: A phase-change optical information recording medium includes, on a transparent substrate, a recording layer in which an optically detectable reversible change between an amorphous phase and a crystalline phase can be caused by irradiation with an energy beam, a reflective layer, and a dielectric layer arranged between the recording layer and the dielectric layer. A main component of the reflective layer is Ag. A main component of the dielectric layer is at least one selected from the group consisting of an oxide of Ta, nitride of Ta and a nitrooxide of Ta. An interface layer may be provided between the recording layer and the dielectric layer. Thus, an optical information recording medium with superior corrosion resistance, improved signal amplitude and high reliability can be provided, as well as a method for manufacturing the same and a method for recording/reproducing the same.

Abstract: The present invention is to provide a method for manufacturing the PCE optical information recording disk under control of not only the crystallization velocity but also the complex index of refraction and thus the reflectance on the disk surface.The PCE optical information recording disk is suitable to be used under the constant angular velocity (the constant rotational numbers wherein the disk has a characteristic that the crystallization velocity is designed to become faster from inside area of the disk to outside area in the radical direction thereof under control of not only the crystallization velocity but also the complex index of refraction and thus the reflectance on the disk surface.

Abstract: A method for manufacturing an optical information recording medium having an excellent mechanical strength, thermal stability, and improved overwrite cycle property can be provided by forming the dielectric layer by using a mixed target comprising ZnS and SiO.sub.2 in an atmosphere comprising rare gas and at least oxygen at the side where the dielectric layer does not contact to the recording layer. The optical information recording medium is manufactured by using the substrate, the recording layer comprising a material that varies reversibly between the optically identifiable states by an irradiation of a laser beam, and the dielectric layer at least one side of which has a two-layered structure at the upper and lower sides of the recording layer. At least one of the dielectric layers that does not contact to the recording layer is formed by using a mixed target comprising ZnS and SiO.sub.2 in a mixed atmosphere comprising rare gas and oxygen.

Abstract: The present invention is to provide a method for manufacturing the PCE optical information recording disk under control of not only the crystallization velocity but also the complex index of refraction and thus the reflectance on the disk surface.The PCE optical information recording disk is suitable to be used under the constant angular velocity (the constant rotational numbers wherein the disk has a characteristic that the crystallization velocity is designed to become faster from inside area of the disk to outside area in the radical direction thereof under control of not only the crystallization velocity but also the complex index of refraction and thus the reflectance on the disk surface.

Abstract: A method for manufacturing an optical information recording medium having an excellent mechanical strength, thermal stability, and improved overwrite cycle property can be provided by forming the dielectric layer by using a mixed target comprising ZnS and SiO.sub.2 in an atmosphere comprising rare gas and at least oxygen at the side where the dielectric layer does not contact to the recording layer. The optical information recording medium is manufactured by using the substrate, the recording layer comprising a material that varies reversibly between the optically identifiable states by an irradiation of a laser beam, and the dielectric layer at least one side of which has a two-layered structure at the upper and lower sides of the recording layer. At least one of the dielectric layers that does not contact to the recording layer is formed by using a mixed target comprising ZnS and SiO.sub.2 in a mixed atmosphere comprising rare gas and oxygen.

Abstract: An optical information storage medium includes a multilayer structure formed on a substrate. The multilayer structure is formed by a sputtering process in a discharge gas and includes at least a first dielectric layer, a recording layer which shows reversible phase change between an amorphous phase and a crystal phase, and a second dielectric layer. The multilayer structure contains sufficiently small amount of the discharge gas so that a limited amount or less of voids of the discharge gas generates in the recording layer during repeated overwrite operations.

Abstract: An optical information recording medium includes: a substrate including a groove having a concave shape and a land having a convex shape adjacent to the groove; and a recording layer on the substrate, wherein the recording layer consists of a material which changes between a first state and a second state whose optical property is different from that of the first state, a first portion of the optical information recording medium including a portion in the first state of the recording layer having a first reflectance, and a second portion of the optical information recording medium including a region in the second state of the recording layer having a second reflectance which is different from the first reflectance, whereby information is recorded onto the groove and the land, and wherein a ratio of the first reflectance to the second reflectance, a phase of reflected light from the first portion and a phase of reflected light from the second portion are set such that at least one of an amplitude and a carrier

Abstract: In mark length modulation recording, a mark end portion correction pulse train is added to a recording pulse train, or laser radiation with bias power is applied between the recording pulse train and laser radiation with cooling power or the mark end portion correction pulse train, furthermore, the start time of the cooling power radiation, the duration of the cooling power radiation, and the shape of the mark end portion correction pulse train are varied in accordance with the mark length to be recorded, further, in CAV mode, the start time of the cooling power radiation or the duration of the cooling power radiation is varied in accordance with disk radius position, and when the recording pulse train consists of a start pulse, an end pulse, and pulses between the start and end pulses, laser radiation with cooling power is applied, or laser radiation with bias power is applied between the recording pulse train and cooling power application, and when the recording pulse train is varied in accordance with mark

Abstract: An optical recording medium according to the present invention includes a substrate, and a recording film formed on the substrate, when receiving a laser beam for recording, the recording film taking either a first structural state or a second structural state according to the intensity of the laser beam; when receiving a laser beam for reproducing, the recording film partially changing the optical phase of the laser beam for reproducing according to the structural state, thereby changing the intensity of the laser beam for reproducing, wherein the optical absorbance of the recording film in the first structural state is substantially equal to that of the recording film in the second structural state, and the refractive index of the recording film in the first structural state is substantially different from that of the recording film in the second structural state.

Abstract: In forming steps of a recording layer or a dielectric layer of a phase change type optical disk by sputtering, a discharge gas which includes at least one of Kr gas and Xe gas is used. Alternatively, at least one of Ar gas and N.sub.2 gas may be further added to the discharge gas. Forming the recording layer or the dielectric layer of the phase change type optical disk in these discharge gases enables preventing of the introduction of the discharge gas into each layer during the forming steps. As a result, the void generation and growth in the recording layer is suppressed. Consequently, the deterioration of the cycle life characteristics due to repeated overwrite operations can be restrained. Therefore, high reliability and long life of the phase change type optical disk is attained.