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: A phase-change optical recording medium capable of implementing record and readout operations of information data through reversible phase transition between amorphous and crystalline states induced by light beam irradiation in a recording layer included in the recording medium, including at least a transparent substrate and contiguous layers formed on the substrate in order as follows, a lower dielectric protective layer, the recording layer, an upper dielectric protective layer, and a reflective/heat dissipating layer, in which the upper dielectric protective layer essentially consists of a mixture of ZrO2 and SiO2, having a composition of (ZrO2)100-x (SiO2)x, where 0<x<60 (mole %).

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 optical information recording medium in which information can be recorded, reproduced and rewritten and which includes a first transparent substrate having a wobbling guide groove which is spirally formed thereon at a pitch; a first dielectric layer located overlying the first transparent substrate and having an optical thickness of from 80 nm to 200 nm; a phase-change recording layer located overlying the first dielectric layer and having an optical thickness of from 20 to 50 nm when the recording layer is in an erased state; a second dielectric layer located overlying the recording layer and having an optical thickness of from 10 nm to 70 nm; a reflection layer located overlying the second dielectric layer; optionally a third dielectric layer located between the second dielectric layer and the reflection layer; and a second transparent substrate located overlying the reflection layer.

Abstract: A flexible optical disk, includes a disk substrate, wherein a rigidity of the disk is equal to or more than 5 Pa and equal to or less than 5000 Pa where the rigidity is defined as Young's modulus of the disk×(thickness of the disk/radius of the disk)3.

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 phase-change optical information recording medium in which information can be recorded, reproduced and rewritten and which includes a first transparent substrate having a wobbling guide groove which is spirally formed thereon at a pitch; a first dielectric layer located overlying the first transparent substrate and having an optical thickness of from 80 nm to 200 nm; a phase-change recording layer located overlying the first dielectric layer and having an optical thickness of from 20 to 50 nm when the recording layer is in an erased state; a second dielectric layer located overlying the recording layer and having an optical thickness of from 10 nm to 70 nm; a reflection layer located overlying the second dielectric layer; optionally a third dielectric layer located between the second dielectric layer and the reflection layer; and a second transparent substrate located overlying the reflection layer.

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 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 disk surface of an optical disk is divided into two regions by a straight line being close to a movement line for an optical pickup to scan and passing in the vicinity of a center of the optical disk. An auxiliary stabilizing member is arranged separately from a main stabilizing member at least one of the two regions.

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: An optical disk apparatus includes a rotary driving unit rotating an optical disk which is flexible, an optical pickup irradiating light upon a recording surface of the optical disk on which writing/reading of information is performed, a stabilizing unit stabilizing vibration of the optical disk in a rotary axial direction by using pressure difference of air flow at least on a portion where writing/reading is performed, and being disposed on a side of the optical disk opposite to a side on which the recording surface is provided, and a control-adjustment unit analyzing a value of a tracking error signal of the optical disk obtained by scanning along a groove of the optical disk with use of the optical pickup, comparing the analyzed value of the tracking error signal of the optical disk and a value priorly obtained by scanning along a groove of a standard disk-prepared beforehand, and adjusting a positional relation between the optical disk and the stabilizing member in a three dimensional space according to t

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 &sgr;repeat/&sgr;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: 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, Cd, 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: A phase-change optical recording medium capable of implementing record and readout operations of information data through reversible phase transition between amorphous and crystalline states induced by light beam irradiation in a recording layer included in the recording medium, including at least a transparent substrate and contiguous layers formed on the substrate in order as follows, a lower dielectric protective layer, the recording layer, an upper dielectric protective layer, and a reflective/heat dissipating layer, in which the upper dielectric protective layer essentially consists of a mixture of ZrO2 and SiO2, having a composition of (ZrO2)100−x (SiO2)x, where 0<x<60 (mole %).

Abstract: A stabilization part stabilizes surface vibration of a flexible optical disk along a rotation axis direction of the optical disk by means of pressure difference of air flow created according to Bernoulli's law at a portion on which information writing/reading is performed, provided on a side of the optical disk opposite to a side on which information recording/reproducing is performed. In this case, areas are provide on the upstream side and down stream side along the disk rotation direction of the portion of the optical disk which is stabilized by said stabilization part, said areas of the optical disk not having pressure difference created thereon by the air flow.

Abstract: An optical information recording medium having a substrate, a first dielectric layer provided on the substrate, a recording layer provided on the first dielectric layer, a second dielectric layer provided on the recording layer, a light reflection and heat dissipation layer provided on the light reflection and heat dissipation layer, and a crystallization accelerating layer provided in contact with at least a portion of the recording layer and made of a material including a substance selected from Bi, Bi-containing compounds, Al, Al-containing compounds, In, In-containing compounds, Tl and Tl-containing compounds.