Abstract: An optical recording medium includes a recording layer including a reflective layer, two dielectric layers, and a phase-change recording layer. The phase-change recording layer-side dielectric layer of the two dielectric layers contains tantalum oxide or a composite oxide composed of silicon oxide, indium oxide, and zirconium oxide. The reflective layer-side dielectric layer of the two dielectric layers contains a composite oxide composed of silicon oxide, indium oxide, and zirconium oxide, a composite oxide composed of indium oxide and gallium oxide, or a composite oxide composed of zinc oxide and aluminum oxide.

Abstract: An optical recording medium includes a recording layer including a reflective layer, two dielectric layers, and a phase-change recording layer. The phase-change recording layer-side dielectric layer of the two dielectric layers contains tantalum oxide or a composite oxide composed of silicon oxide, indium oxide, and zirconium oxide. The reflective layer-side dielectric layer of the two dielectric layers contains a composite oxide composed of silicon oxide, indium oxide, and zirconium oxide, a composite oxide composed of indium oxide and gallium oxide, or a composite oxide composed of zinc oxide and aluminum oxide.

Abstract: An optical recording medium includes: a substrate having a first principal surface and a second principal surface; one or plural information signal layers formed on the first principal surface of the substrate for undergoing recording or reproduction of information signals upon irradiation with light; and a barrier layer formed on the second principal surface of the substrate for suppressing the gas release from the second principal surface of the substrate, wherein an area of a region exposing from the barrier layer of the second principal surface of the substrate is not more than 688 mm2.

Abstract: An optical recording medium includes: a substrate; an information signal layer provided on the substrate; and a protective layer provided on the information signal layer. The information signal layer is provided with a reflecting layer, a recording layer provided on the reflecting layer and first, second and third dielectric layers laminated successively on the recording layer. Refractive indexes of the first, second and third dielectric layers are different from each other between the adjacent dielectric layers to each other. Among the first, second and third dielectric layers, the dielectric layer having the highest refractive index contains, as a main component, at least one member selected from the group consisting of titanium oxide, niobium oxide and a mixture of zinc sulfide and silicon oxide. The dielectric layer having the highest refractive index has a refractive index of 2.3 or more at a wavelength of 405 nm.

Abstract: Binary information previously recorded in an innermost rim side area is enabled to be stably reproduced. A record medium is formed by sequentially laminating a first information layer 2, an intermediate layer 3, a second information layer 4, and a cover layer 5 onto a substrate 1. First grooves are previously formed in the innermost rim area of the substrate 1. Second grooves are previously formed in an area where data is recorded. The first grooves are set to be shallower and narrower than the second grooves. Thus, such a situation that a BCA signal is modulated by diffraction due to the grooves can be reduced.

Abstract: An optical recording medium includes: a substrate having a first principal surface and a second principal surface; one or plural information signal layers formed on the first principal surface of the substrate for undergoing recording or reproduction of information signals upon irradiation with light; and a barrier layer formed on the second principal surface of the substrate for suppressing the gas release from the second principal surface of the substrate, wherein an area of a region exposing from the barrier layer of the second principal surface of the substrate is not more than 688 mm2.

Abstract: A recording method whereby an inorganic resist made of an incomplete oxide of a transition metal is formed as a film onto a substrate and a latent image corresponding to pits is formed onto the inorganic resist by exposure. The exposure is performed by a laser beam whose intensity has been modulated by a pulse signal whose pulse height decreases in a rear portion in a length direction of the pit, thereby forming a format of a track pitch smaller than a recording beam diameter (track pitch/exposure beam diameter=0.333 to 0.833).

Abstract: A recording method whereby an inorganic resist made of an incomplete oxide of a transition metal is formed as a film onto a substrate and a latent image corresponding to pits is formed onto the inorganic resist by exposure. The exposure is performed by a laser beam whose intensity has been modulated by a pulse signal whose pulse height decreases in a rear portion in a length direction of the pit, thereby forming a format of a track pitch smaller than a recording beam diameter (track pitch/exposure beam diameter=0.333 to 0.833).

Abstract: An optical recording medium includes: a substrate; an information signal layer provided on the substrate; and a protective layer provided on the information signal layer. The information signal layer is provided with a reflecting layer, a recording layer provided on the reflecting layer and first, second and third dielectric layers laminated successively on the recording layer. Refractive indexes of the first, second and third dielectric layers are different from each other between the adjacent dielectric layers to each other. Among the first, second and third dielectric layers, the dielectric layer having the highest refractive index contains, as a main component, at least one member selected from the group consisting of titanium oxide, niobium oxide and a mixture of zinc sulfide and silicon oxide. The dielectric layer having the highest refractive index has a refractive index of 2.3 or more at a wavelength of 405 nm.

Abstract: Binary information previously recorded in an innermost rim side area is enabled to be stably reproduced. A record medium is formed by sequentially laminating a first information layer 2, an intermediate layer 3, a second information layer 4, and a cover layer 5 onto a substrate 1. First grooves are previously formed in the innermost rim area of the substrate 1. Second grooves are previously formed in an area where data is recorded. The first grooves are set to be shallower and narrower than the second grooves. Thus, such a situation that a BCA signal is modulated by diffraction due to the grooves can be reduced.

Abstract: A recording method whereby an inorganic resist made of an incomplete oxide of a transition metal is formed as a film onto a substrate and a latent image corresponding to pits is formed onto the inorganic resist by exposure. The exposure is performed by a laser beam whose intensity has been modulated by a pulse signal whose pulse height decreases in a rear portion in a length direction of the pit, thereby forming a format of a track pitch smaller than a recording beam diameter(track pitch/exposure beam diameter=0.333 to 0.833).

Abstract: A recording method whereby an inorganic resist made of an incomplete oxide of a transition metal is formed as a film onto a substrate and a latent image corresponding to pits is formed onto the inorganic resist by exposure. The exposure is performed by a laser beam whose intensity has been modulated by a pulse signal whose pulse height decreases in a rear portion in a length direction of the pit, thereby forming a format of a track pitch smaller than a recording beam diameter (track pitch/exposure beam diameter=0.333 to 0.833).

Abstract: A recording method whereby an inorganic resist made of an incomplete oxide of a transition metal is formed as a film onto a substrate and a latent image corresponding to pits is formed onto the inorganic resist by exposure. The exposure is performed by a laser beam whose intensity has been modulated by a pulse signal whose pulse height decreases in a rear portion in a length direction of the pit, thereby forming a format of a track pitch smaller than a recording beam diameter (track pitch/exposure beam diameter=0.333 to 0.833).

Abstract: A recording method whereby an inorganic resist made of an incomplete oxide of a transition metal is formed as a film onto a substrate and a latent image corresponding to pits is formed onto the inorganic resist by exposure. The exposure is performed by a laser beam whose intensity has been modulated by a pulse signal whose pulse height decreases in a rear portion in a length direction of the pit, thereby forming a format of a track pitch smaller than a recording beam diameter (track pitch/exposure beam diameter=0.333 to 0.833).

Abstract: An in-plane magnetic recording medium includes a resin substrate and an underlayer, the resin substrate formed without requiring a complex manufacturing process and having an optimum surface smoothness. The underlayer provides a satisfactory in-plane orientation property to a magnetic film, whereby high coercive force and high S/N ratio are provided in the magnetic recording medium, thus making the magnetic recording medium suitable for high density recording. The in-plane magnetic recording medium includes at least a substrate made of resin, an underlayer made of an alloy of Ti and tungsten W, an intermediate layer having a hexagonal close-packed structure, a magnetic film mainly composed of Co, a protecting film and a lubricant coat, successively provided one on another. The underlayer is made of an alloy of Ti containing W between 25 and 60 atomic percent, and the thickness thereof falls within 5 nm and 25 nm.

Abstract: A magnetic recording medium having a high coercive force and a high signal to noise ratio suitable for use in a high density recording, and a method of manufacture thereof are provided, by using a resin substrate capable of processing approximately at room temperatures. A magnetic film mainly comprising Co—Pt—Cr and including a silicon oxide is formed on the resin substrate wherein an amount of silicon element constituting the silicon oxide in terms of atomic percent relative to the Co—Pt—Cr is 8 atomic % or more and 16 atomic % or less, thereby efficiently decreasing the inter-crystal interaction between crystal grains therein. Further, the magnetic film is formed on the substrate made of the resin in the non-heated state by sputtering in a sputtering chamber at a gas pressure of 0.133 Pa or more and 2.66 Pa or less.