Abstract: An optical recording medium having an inorganic recording film, wherein the inorganic recording film has: a first recording film containing titanium Ti; and a second recording film containing oxides of germanium Ge and tin Sn.

Abstract: A write once optical recording medium includes a substrate on which an oxide film serving as an inorganic recording film is formed, the oxide film being made of a recording material of an oxide Ge1Ox (x is an atomic number ratio) of germanium (Ge) and a composition of Ge1Ox of the oxide film being specified so as to satisfy 1.0<x<2.0.

Abstract: An optimum performance is achieved relative to write-once type optical recording mediums on which information is recorded by means of a blue-violet semiconductor laser. An optical disc recording/reproduction apparatus 10 comprises an LD control section 17 adapted to control the irradiation power of a laser when writing data. If the cycle of the channel clock is T, when forming a recording mark having a length of n×T (n being an integer not smaller than 2), a pulse beam is irradiated onto the write-once type information recording medium for n/2 times (decimals, if any, being to be rounded down). When forming a recording mark having a length of not smaller than 6T and even number times of T, a pulse beam is irradiated for n/2 times with all the intermediate pulse beams synchronized with the phase of the channel clock except the leading pulse beam and the tail end pulse beam.

Abstract: A write once optical recording medium has an inorganic recording film which includes an oxide film having germanium oxide (GeO) as a principal component, and a metal film adjacent to the oxide film, the metal film having a titanium/silicon alloy (TiSi) as a principal component. According to this arrangement, it is possible to construct an inexpensive write once optical recording medium with large strength capable of high density recording by using a short wavelength light source and an optical system with a high numerical aperture having excellent characteristics.

Abstract: An optical recording medium having two or more information recording layers in which information is recorded at a high recording density. The optical recording medium is comprised of information recording layers between a first surface at which light is incident and a second surface opposite the first surface. The first information recording layer nearest to the second surface is a phase-modulation information recording layer, and the second information recording layer is a reflectance-modulation information recording layer.

Abstract: A rewritable optical information recording medium including a recording layer composed of an organic dye film is provided, in which recording and erasing information can be performed reversibly by laser light irradiation. A rewritable optical information recording medium including at least one organic dye film which is substantially made of only at least one kind of organic dye compounds as a recording film is provided. The recording and erasure of information are performed by a reversible physical change of the organic dye film substance caused by laser light irradiation.

Abstract: A write once optical recording medium includes a substrate on which an oxide film 3 constituting an inorganic recording film is formed, the oxide film 3 being made of a recording material of an oxide Ge1Ox (x is an atomic number ratio) of germanium (Ge) and a composition of Ge1Ox of the oxide film being specified so as to satisfy 1.0<x<2.0. Recording and reproducing characteristics of the write once optical recording medium can be improved and an arrangement of this write once optical recording medium can be simplified.

Abstract: An optical recording medium having at least a recording layer 11 and a light transmitting layer 13 formed on a substrate 10, in which the recording layer 11 is made of an organic material for absorbing an incident light of wavelength of 360 nm to 460 nm, and inducing physical change or chemical change to vary the refractive index, the light transmitting layer 13 is 10 ?m to 177 ?m in thickness, the relation between absorption coefficient “k” and pyrolysis temperature Tdec of organic material is 950(° C.)<(Tdec (° C.)?20)/k<4100° C.??(1), and the absorption coefficient “k” is k>0.0.

Abstract: An optimum performance is achieved relative to write-once type optical recording mediums on which information is recorded by means of a blue-violet semiconductor laser. An optical disc recording/reproduction apparatus 10 comprises an LD control section 17 adapted to control the irradiation power of a laser when writing data. If the cycle of the channel clock is T, when forming a recording mark having a length of n×T (n being an integer not smaller than 2), a pulse beam is irradiated onto the write-once type information recording medium for n/2 times (decimals, if any, being to be rounded down). When forming a recording mark having a length of not smaller than 6T and even number times of T, a pulse beam is irradiated for n/2 times with all the intermediate pulse beams synchronized with the phase of the channel clock except the leading pulse beam and the tail end pulse beam.

Abstract: A disk type optical recording medium that can limit the reproduction by a disk drive connected to a computer without drastically changing the specifications of recorded information on the medium conventionally processed by a dedicated player, thereby preventing illegal copying or the like. The disk type optical recording medium has information tracks formed by a pit train, and the information tracks have a read limiting region formed by a modified pit train including a special wobble or lateral displacement as modified from the pit train. In this read limiting region, the modified pit train can be followed by the tracking control of an optical pickup during low-speed rotation of the medium, thereby allowing proper reproduction. However, the modified pit train cannot be followed by the tracking control of the optical pickup during high-speed rotation of the medium, thereby disallowing the reproduction.

Abstract: A light orientation film and a liquid crystal thin film are formed adjacent to each other. Light is irradiated to the light orientation film and the liquid crystal thin film, so as to cause the light orientation film to be orientated while viscosity of the liquid crystal thin film is lowered by a temperature increase by the light irradiation, so that an intermolecular force on the boundary between the light orientation film and the liquid crystal thin film causes the liquid crystal molecules in the liquid crystal thin film to the orientation of the light orientation film. By this orientation of the liquid crystal molecules, recording information is maintained. Thus, it is possible to realize a sufficient signal amount while using the light orientation film as well as to obtain a thermal stability and a stability against light irradiation.

Abstract: A phase modulation type optical recording medium has at least one layer of recording film 4 and at least one layer of metal film 3 on a substrate 1 having recessed portions formed therein, wherein one or more layers constituting the recording film include organic material that decomposes upon absorption of laser light to change its refractive index, and width of the recessed portions 2 is set to 0.10 ?m˜0.21 ?m, thereby providing an optical recording medium of write once type with high recording density capable of high reproduction output.

Abstract: Optical data medium containing in the information layer, a dye as a light-absorbing compound Abstract optical data medium containing a preferably transparent substrate which is optionally already coated with one or more barrier layers and on the surface of which an information layer which can be recorded on using light, optionally one or more barrier layers, and a cover layer containing a radiation-cured resin, have been applied, which data medium can he recorded on and read using focused blue light through the cover layer on the information layer, preferably laser light with the wavelength between 360 nm and 460 nm, the information layer containing a light-absorbing characterized in that at least one dye is used as the light-absorbing compound wherein the cover layer dies have a total thickness of 10 &mgr;m 177 m and the numerical aperture NA of the focusing objective lens setup is greater or equal 0.8.

Abstract: There is provided a disk type optical recording medium and a reproduction limitation method for a disk type optical recording medium for preventing illegal copying, etc. to achieve protection of digital contents.

Abstract: The present invention relates to an optical recording medium having a plurality of recording layers having different uses. The optical recording medium includes a first light transmitting layer (32); a layer (31) composed of an organic dye for recording and reading data by an optical beam of a first wavelength incident through the first light transmitting layer (32) and transmitting an optical beam of a second wavelength incident through the first light transmitting layer (32); a second light transmitting layer (34) for transmitting the optical beam of the second wavelength incident through the layer (31) composed of the organic dye; and a reflecting layer (331) for reflecting the optical beam of the second wavelength incident through the second light transmitting layer (34).

Abstract: The present invention provides an optical recording medium in which two or more information-recording layers are laminated for obtaining a high recording density, and also incidence of light and detection of return light can be performed with high efficiency relating to an information-recording layer at a position distant from a light-incident side, thus having satisfactory recording and reproduction characteristics; and also provides an optical recording and reproducing method for performing at least recording or reproduction of information using this optical recording medium.

Abstract: A phase modulation type optical recording medium has at least one layer of recording film 4 and at least one layer of metal film 3 on a substrate 1 having recessed portions formed therein, wherein one or more layers constituting the recording film include organic material that decomposes upon absorption of laser light to change its refractive index, and width of the recessed portions 2 is set to 0.10 &mgr;m-0.21 &mgr;m, thereby providing an optical recording medium of write once type with high recording density capable of high reproduction output.

Abstract: An optical recording medium is capable of linear recording in a photon mode. An organic material changed in molecular orientation on light illumination to exhibit birefringence is used as a recording material. For example, a recording layer having, as a recording material, an organic material changed in molecular orientation caused by trans-cis rearrangement, is changed in birefringence with changes in the molecular orientation of the organic material. The recording system which utilizes the changes in the molecular orientation of the organic material has linear characteristics and gives outputs different depending on e.g., the degree or the angle of orientation, thus enabling multi-valued recording.

Abstract: Optical data medium containing a preferably transparent substrate which is optionally already coated with one or more barrier layers and on the surface of which an information layer which can be recorded on using light, optionally one or more barrier layers, and a cover layer, have been applied, which data medium can be recorded on and read using focused blue light through the cover layer on the information layer, preferably laser light with the wavelength between 360 nm and 460 nm, the information layer containing a light-absorbing compound and optionally a binder, characterized in that at least one dye is used as the light-absorbing compound wherein the cover layer on the top of the information layer including the adhesive layer do have a total thickness of 10 &mgr;m to 177 &mgr;m and the numerical aperture NA of the focusing objective lens setup is greater or equal 0.8.

Abstract: To provide a high density optical recording medium, capable of realizing the complete compatibility with a phase change recording medium with respect to an optical pickup or a drive device, using a short wavelength light for achieving a high recording density. The present invention provides an optical recording medium configuration for directly reading out the change of the reflectance without using the phase modulation method. An optical recording medium according to the present invention is an optical recording medium having a recording film of a single layer or multiple layer structure on a substrate (1), wherein the recording film is mainly made of an organic substance material layer (2) for absorbing and decomposing a laser beam, and generating the refractive index change as well as the reflectance of the optical recording medium with respect to a reproduction laser beam of a 380 nm to 450 nm wavelength is 15% to 25% before the decomposition, and 0% to 10% after the decomposition.