Abstract: A multilayer optical recording medium in which, as a recording layer is located farther from a surface of incidence of a light beam for reading, the amount of light that reaches the surface of incidence after being reflected off the recording layer is smaller.

Abstract: A multilayer optical recording medium in which, as a recording layer is located farther from a surface of incidence of a light beam for reading, the amount of light that reaches the surface of incidence after being reflected off the recording layer is smaller.

Abstract: [PROBLEMS] To perform highly accurate focus control in an optical recording medium of multilayer structure having an interface of each layer with a reflectance reduced as much as possible. [SOLVING ELEMENT] In a focus control apparatus with optical pickup for use in an optical recording medium of multilayer structure, laser light irradiating device including a laser light source (50) and an objective lens (54) irradiates laser light to an optical recording medium (D), a photodetector (55) detects an optical characteristic change associated with multiphoton absorption caused when the laser light is condensed to at least one of recording layers, and in accordance with the detection result, focus control in the optical pickup is performed for an arbitrary recording layer (L1 to Ln).

Abstract: A polycrystalline aluminum thin film is made of polycrystals of an alloy of aluminum. The polycrystalline aluminum thin film includes a first additive which is distributed with even concentration over an inside of each crystal grain and an interface of the crystal grain and a second additive which is distributed with higher concentration in the interface of the crystal grain than in the inside of the crystal grain.

Abstract: A polycrystalline aluminum thin film is made of polycrystals of an alloy of aluminum. The polycrystalline aluminum thin film includes a first additive which is distributed with even concentration over an inside of each crystal grain and an interface of the crystal grain and a second additive which is distributed with higher concentration in the interface of the crystal grain than in the inside of the crystal grain.

Abstract: A polycrystalline aluminum thin film is made of polycrystals of an alloy of aluminum. The polycrystalline aluminum thin film includes a first additive which is distributed with even concentration over an inside of each crystal grain and an interface of the crystal grain and a second additive which is distributed with higher concentration in the interface of the crystal grain than in the inside of the crystal grain.

Abstract: A polymerizable spherical transition metal complex is provided which has a hollow shell which is formed from transition metal atoms and bidentate organic ligands, the bidentate organic ligands having a substituent having a polymerizable group moiety at an end thereof, and the substituents being oriented towards the interior of the hollow shell. A spherical transition metal complex in which, in the hollow shell of the polymerizable spherical transition metal complex, the polymerizable groups are polymerized, and a production method thereof are also provided.

Abstract: A magnetic head for use in a magnetic recording apparatus for magnetically recording information in a state of heating and elevating the temperature of a recording portion of a recording medium by emitting electrons to the recording medium, the magnetic head including a recording magnetic pole having a magnetic surface opposed to the recording medium, and supplying a magnetic flux to the recording medium and an electron emitting source formed in the recording magnetic pole. The electron emitting source has a concave portion having an opening formed in the recording magnetic pole and open to the recording magnetic pole surface and a bundle of a plurality of carbon nanotubes each extending from the bottom to the opening of the concave portion.

Abstract: A polycrystalline aluminum thin film is made of polycrystals of an alloy of aluminum. The polycrystalline aluminum thin film includes a first additive which is distributed with even concentration over an inside of each crystal grain and an interface of the crystal grain and a second additive which is distributed with higher concentration in the interface of the crystal grain than in the inside of the crystal grain.

Abstract: Diffusion of water or oxygen present in the dielectric protection film is restrained by eliminating free oxygen in an oxide thin film while maintaining the characteristics of a dielectric protection film. As the dielectric material for forming a dielectric protection film for an optical disc or the like, an oxide mixture thin film of a niobium oxide and one of a silicon oxide and a titanium oxide is used. In a preferable example, a target made of a niobium oxide as the main component with 1 to 30% by weight of a silicon oxide added is used for formation of an oxide thin film by sputtering. Moreover, the oxide thin film is formed preferably in a nitrogen atmosphere. A nitrogen containing oxide thin film is produced by carrying out sputtering using a target with the oxygen lacked and a minute amount of nitrogen added. Thereby, a thin film having little reducing function and a high barrier property while having the characteristics comparable to a complete oxide can be produced.

Abstract: Hardness of a resin substrate of an optical disc is selected to be greater than hardness of a cover layer of the optical disc, at least when information is recorded on the optical disc. A laser beam is transmitted to an organic dye layer of the optical disc through the cover layer and a protection layer when information is recorded on the optical disc. The organic dye layer is sandwiched by the protection layer and a reflection layer. The substrate has grooves on its surface, and information is recorded between the grooves. The organic dye is heated and expands upon information recording, but a stress generated by the deforming organic dye layer is mainly transferred toward the cover layer. Deformation of the reflection layer and crosswrite upon information recording can be prevented. Therefore, the optical disc can record information between the grooves at a high density.

Abstract: A magnetic head for use in a magnetic recording apparatus for magnetically recording information in a state of heating and elevating the temperature of a recording portion of a recording medium by emitting electrons to the recording medium, the magnetic head including a recording magnetic pole having a magnetic surface opposed to the recording medium, and supplying a magnetic flux to the recording medium and an electron emitting source formed in the recording magnetic pole. The electron emitting source has a concave portion having an opening formed in the recording magnetic pole and open to the recording magnetic pole surface and a bundle of a plurality of carbon nanotubes each extending from the bottom to the opening of the concave portion.

Abstract: Hardness of a resin substrate of an optical disc is selected to be greater than hardness of a cover layer of the optical disc, at least when information is recorded on the optical disc. A laser beam is transmitted to an organic dye layer of the optical disc through the cover layer and a protection layer when information is recorded on the optical disc. The organic dye layer is sandwiched by the protection layer and a reflection layer. The substrate has grooves on its surface, and information is recorded between the grooves. The organic dye is heated and expands upon information recording, but a stress generated by the deforming organic dye layer is mainly transferred toward the cover layer. Deformation of the reflection layer and crosswrite upon information recording can be prevented. Therefore, the optical disc can record information between the grooves at a high density.

Abstract: The invention relates to a method of manufacturing a multilayer optical disc which is not formed with voids in an optically transparent zone, and a multilayer optical disc. The method of manufacturing a multilayer optical information recording medium having at least a first and a second information recording layer includes the steps of forming the first information recording layer, applying a porous resin film on the first information recording layer, impregnating the porous resin film with a liquid functional resin, bringing a stamper into pressure contact with the porous resin film and curing the functional resin, and removing the stamper so that the second information recording layer is formed on the substrate.

Abstract: A recording medium (10) is formed by laminating a conductive layer (11), a ferroelectric layer (12), a control layer (13), and a conductive layer (14), in order. Moreover, the control layer (13) is formed from a material that has an insulation property in a normal state but becomes conductive by irradiation of an energy beam. Then, the insulation property and conductivity of the control layer (13) is changed by presence or absence, or strength or weakness of the irradiation of the energy beam (B). When the control layer (13) exhibits the conductivity, a voltage supplied between the conductive layers (11, 14) is applied to the ferroelectric layer (12). When the control layer (13) exhibits the insulation property, the application of the voltage is cut off. The application and cut-off of the voltage to the ferroelectric layer (12) realize recording of information into the ferroelectric layer (12).

Abstract: An optical disk includes a substrate, a reflection layer, an organic dye layer, a protection layer and a cover layer. When recording information on the optical disk by a laser beam, an organic dye expands due to heat generation caused by laser beam radiation. The laser beam passes through the cover layer of the optical disk during recordation. The information is recorded in grooves formed in the substrate. Hardness of a resin substrate side of the optical disk is higher than that of a cover layer side of the optical disk so as to propagate stresses generated by the thermal expansion of the organic dye toward the cover layer. The hardness relationship between the cover layer side and the substrate side should be established at least when the information is recorded on the optical disk. The optical disk can record the information more finely because deformations of the reflection layer are prevented when recording the information.

Abstract: A focusing control apparatus includes method for an optical pickup having an objective lens and an aberration correcting unit includes the steps of detecting an amount of focus error of a light beam and an amount of aberration of the reflected light beam to generate a focus error value and an aberration value; controlling a focused position of the objective lens on the basis of the focus error value while adjusting an amount of aberration correction of the aberration correcting unit on the basis of the aberration value, and performing a focus jump from one recording layer to another recording layer after adjusting the amount of aberration correction of the aberration correcting unit for the another recording layer.

Abstract: To present an optical recording medium having four or more information recording planes which can be read from one side. A first reflective layer 3 has a layer mainly composed of titanium oxide, a second reflective layer 5 has a layer mainly composed of titanium oxide, a third reflective layer 7 has a layer of an alloy mainly composed of silver, and a fourth reflective layer 9 has a layer of an alloy mainly composed of aluminum.

Abstract: The present invention provides an optical information recording medium with favorable signal reproduction characteristics that comprises a substrate, a reflective layer and a protective layer, and performs playback by allowing a laser beam for signal playback to enter via the protective layer, wherein the substrate is provided with a phase pit array for holding information. Each phase pit of the phase pit array is formed as a cavity which is reentrant as viewed from the entrance side of the signal playback laser beam.

Abstract: An optical disk includes a substrate, a reflection layer, an organic dye layer, a protection layer and a cover layer. When recording information on the optical disk by a laser beam, an organic dye expands due to heat generation caused by laser beam radiation. The laser beam passes through the cover layer of the optical disk during recordation. The information is recorded in grooves formed in the substrate. Hardness of a resin substrate side of the optical disk is higher than that of a cover layer side of the optical disk so as to propagate stresses generated by the thermal expansion of the organic dye toward the cover layer. The hardness relationship between the cover layer side and the substrate side should be established at least when the information is recorded on the optical disk. The optical disk can record the information more finely because deformations of the reflection layer are prevented when recording the information.