Abstract: An optical recording medium including a substrate, an information recording layer including a recording layer and a cover layer, wherein information is written and read on the information recording layer by irradiation of laser beam via the cover layer, the cover layer includes an ultraviolet curing resin and an inner hardness Hi defined as hardness H of the cover layer on a side of the information recording layer satisfies the following relationship: 3.8?Hi?5.5, when H=3.8584×F/(h×h), wherein h represents an indented depth in a state in which a triangular pyramid indenter with a tip angle of 115° is pressed under F=9.8 mN.

Abstract: It is an object of the present invention to provide an optical recording medium containing a substrate, and a reflective layer, a second dielectric layer, a recording layer and a first dielectric layer which are disposed over the substrate in this order, wherein the recording layer contains a phase-change recording material containing any one of GeSbSnMn and GeSbSnMnGa, and the second dielectric layer contains an oxide of two or more elements of Nb, Si and Ta.

Abstract: An optical recording medium including a substrate, an information recording layer including a recording layer and a cover layer, wherein information is written and read on the information recording layer by irradiation of laser beam via the cover layer, the cover layer includes an ultraviolet curing resin and an inner hardness Hi defined as hardness H of the cover layer on a side of the information recording layer satisfies the following relationship: 3.8?Hi?5.5, when H=3.8584×F/(h×h), wherein h represents an indented depth in a state in which a triangular pyramid indenter with a tip angle of 115° is pressed under F=9.8 mN.

Abstract: An optical recording medium which comprises a phase-change recording layer utilizing optical constants associated with a reversible-phase-change induced by laser beam irradiation between an amorphous phase and a crystalline phase. The phase-change recording layer comprises Ge, Sb, Sn, Mn, and X. X represents at least one element selected from In, Bi, Te, Ag, Al, Zn, Co, Ni, and Cu. When the relation of respective contents thereof is represented by Ge?Sb?Sn?Mn?X?, elements of ?, ?, ?, ?, and ? respectively satisfy the following numerical expressions: 5???25, 45???75, 10???30, 0.5???20, and 0???15 (atomic %) when ?+?+?+?+?=100), and the total content of of Ge, Sb, Sn, Mn, and X is 95 atomic % of the entire content of the phase-change recording layer.

Abstract: In an optical disk substrate film-formation apparatus which prepared an optical disk by forming a thin film on a substrate, the optical disk substrate is held by a holder section. A contact support surface is provided to the holder section which closely contacts at least a portion of the surface of the optical disk substrate rear to the surface where the think film is formed.

Abstract: In an optical disk substrate film-formation apparatus which prepared an optical disk by forming a thin film on a substrate, the optical disk substrate is held by a holder section. A contact support surface is provided to the holder section which closely contacts at least a portion of the surface of the optical disk substrate rear to the surface where the think film is formed.

Abstract: In an optical disk substrate film-formation apparatus which prepared an optical disk by forming a thin film on a substrate, the optical disk substrate is held by a holder section. A contact support surface is provided to the holder section which closely contacts at least a portion of the surface of the optical disk substrate rear to the surface where the think film is formed.

Abstract: In an optical disk substrate film-formation apparatus which prepared an optical disk by forming a thin film on a substrate, the optical disk substrate is held by a holder section. A contact support surface is provided to the holder section which closely contacts at least a portion of the surface of the optical disk substrate rear to the surface where the think film is formed.

Abstract: A phase-change recording medium with Sb3Te compounds which are formed by initialization-less process steps is provided through the formation of recording media having layered structure including suitably selected materials together with methods for fabricating such recording media, thereby leading to DVD-ROM compatible recording media capable of achieving recording density of 2.6 GB or more on a disc of 120 mm in diameter. The recording medium includes an Sb3Te recording layer and a crystallization accelerating layer formed contiguously with the recording layer. The crystallization accelerating layer is formed to suitably include impurities as record stabilization agents. At least one additional impurity layer may be formed contiguous to said recording and/or crystallization accelerating layer.