Abstract: An optical disc manufacturing method includes: an injection step of injecting a liquid material into a circular plate-shaped injection space having a center hole portion at a center from an injection hole connected to an inner edge portion in the injection space; a discharge step of discharging air and the liquid material from a discharge hole formed on a straight line passing through the injection hole and a center of the center hole portion in a plane direction of the circular plate and at a position opposite to the injection hole; a curing step of curing the liquid material injected into the injection space; and a takeout step of taking out the cured liquid material from the injection space.

Abstract: An optical information recording medium includes a recording layer that includes a mark layer in which recording marks formed in accordance with condensed recording light are aligned and has a recording light absorption amount of 20.8% or less with respect to an innermost depth as a depth of the mark layer from a side thereof that the recording light enters to a side thereof that is most distant from the side that the recording light enters, and a change amount of a light absorption amount with respect to measurement light having a wavelength 10 nm shorter than that of the recording light at a time a light absorption amount with respect to measurement light having the same wavelength as the recording light is used as a reference, of 8.0% or more per 0.30 mm.

Abstract: A hologram recording medium includes a stack of at least a lower transparent substrate, a recording layer made of a photocurable organic material, and an upper transparent substrate, wherein a spacer for keeping a thickness of the recording layer is dispersed and disposed in the inside of the recording layer in a direction of a principal plane of the hologram recording medium.

Abstract: A method of producing a mold for use in duplicating a light diffusion sheet is provided. The method includes a step of conducting sand blasting for blasting abrasive material from a blast gun to a surface of a mold base material to form unevenness in the surface of the mold base material, wherein the abrasive material is blasted to the surface of the mold base material at a blast angle of less than 90°.

Abstract: The present invention can record or reproduce information in a stable manner with a simple configuration. According to the present invention, since a photoinitiator whose vaporization temperature is between 140 and 400 deg C. is included, a portion around a focal point Fb of a recording optical beam L2c heats up after the recording optical beam L2c is focused, vaporizing the photoinitiator. As a result, an air bubble is formed. This air bubble is left in a recording layer 101 as a cavity after the emission of the recording optical beam L2c ends and the portion around the focal point Fb cools down. When a reading optical beam L2d is emitted, the air bubble can reflect the reading optical beam L2d due to the difference in refractive index between a portion inside the air bubble and the portion outside the air bubble (i.e. the recording layer 101), producing a returning optical beam L3.

Abstract: An optical information recording medium includes a recording layer that absorbs recording light in accordance with its wavelength, the recording light being condensed for information recording, and increases the temperature in the vicinity of a focus so as to form a recording mark and that has properties of increasing a light absorption amount with respect to the wavelength of the recording light by heating performed at a temperature of 120° C. or more.

Abstract: An optical information recording medium includes a recording layer that absorbs recording light in accordance with its wavelength, the recording light being condensed for information recording, and increases the temperature in the vicinity of a focus so as to form a recording mark and that has properties of increasing a light absorption amount with respect to the wavelength of the recording light when light having the wavelength of the recording light is radiated.

Abstract: An optical pickup includes: a light source that emits first light; an objective lens that condenses the first light and allows it to irradiate a track having formed therein a recording mark for intercepting the first light in a uniform recording layer of an optical information recording medium; and a light receiving section that receives transmitted light which has transmitted through the track.

Abstract: A tensioner for an endless transmission belt includes a plunger body and a plunger. The plunger is movably provided in the plunger body to press the endless transmission belt. A pressure chamber provided between the plunger and the plunger body is configured to store hydraulic oil supplied from an oil pump. A check valve is provided in the plunger body, configured to be opened to supply the hydraulic oil to the pressure chamber when a pressure in the pressure chamber is lower than an oil pressure from the oil pump, and configured to be closed when the pressure is higher than the oil pressure. A relief valve is provided in the plunger body within a width of the plunger in a direction orthogonal to a longitudinal direction of the plunger and configured to discharge the hydraulic oil in the pressure chamber when the pressure exceeds a predetermined value.

Abstract: A tensioner for an endless transmission belt includes a plunger body. A plunger is movably provided in a hole of the plunger body to press the belt. A chamber is provided between the plunger and the plunger body to store hydraulic oil. An oil supply passage is provided in the plunger body to supply the oil from an oil pump to the chamber. A check valve is provided between the chamber and the passage and configured to allow the oil to be supplied from the pump to the chamber while the check valve is configured to be closed when a pressure in the chamber is higher than a pressure of the oil supplied by the pump. A relief valve is provided between the chamber and the passage and configured to discharge the oil in the chamber to the passage when the pressure in the chamber exceeds a first predetermined value.

Abstract: An optical information recording medium contains a recording layer that includes: a recording area on which a cavity is formed as a recording mark as a result of an increase in temperature around a focal point after absorbing a recording beam converged for recording of information in accordance with the wavelength of the recording beam and from which, when a predetermined reading beam is emitted for reproducing of the information, the information is reproduced based on the optically modulated reading beam; and a non-recording area provided adjacent to the recording area to prevent the heat around the focal point from dispersing.

Abstract: An optical information recording medium includes a recording layer provided on a cured resin on which a recording mark is formed by the temperature rise around a focal point caused by absorbing a predetermined recording beam converged for recording of information according to the wavelength of the recording beam and from which the information is reproduced, when a predetermined reading beam is emitted for reproducing of the information, based on the optically-modulated reading beam, wherein the recording layer includes an activated recording area that has been activated as a result of being exposed to an activating beam whose light intensity is at a predetermined light intensity level.

Abstract: A method of producing a mold for use in duplicating a light diffusion sheet is provided. The method includes a step of conducting sand blasting for blasting abrasive material from a blast gun to a surface of a mold base material to form unevenness in the surface of the mold base material, wherein the abrasive material is blasted to the surface of the mold base material at a blast angle of less than 90°.

Abstract: A method of producing a mold for use in duplicating a light diffusion sheet is provided. The method includes a step of conducting sandblasting for blasting abrasive material from a blast gun to a surface of a mold base material to form unevenness in the surface of the mold base material, wherein the abrasive material is blasted to the surface of the mold base material at a blast angle of less than 90°.

Abstract: A hologram recording medium includes a stack of at least a lower transparent substrate, a recording layer made of a photocurable organic material, and an upper transparent substrate, wherein a spacer for keeping a thickness of the recording layer is dispersed and disposed in the inside of the recording layer in a direction of a principal plane of the hologram recording medium.

Abstract: A method of producing a mold for use in duplicating a light diffusion sheet is provided. The method includes a step of conducting sandblasting for blasting abrasive material from a blast gun to a surface of a mold base material to form unevenness in the surface of the mold base material, wherein the abrasive material is blasted to the surface of the mold base material at a blast angle of less than 90°.

Abstract: In a plastic card (10) for an embossing finish comprising a core material (12) and a sheath material (13), a breaking elongation of the core material (12) is 25% or less and a breaking elongation of the sheath material (13) is 130% or more. The ratio of the thickness of the core material to the thickness of the sheath material (13) occupied in the entire part of the plastic card is set to 20 to 53:10. Otherwise, a breaking elongation of the core material (12) is 50% or less and the tensile strength of the sheath material (13) is 100 MPa or more. The ratio of the thickness of the sheath material (13) to the thickness of the core material (12) occupied in the entire part of the card is set to 41 to 90:10.

Abstract: In a plastic card (10) for an embossing finish comprising a core material (12) and a sheath material (13), a breaking elongation of the core material (12) is 25% or less and a breaking elongation of the sheath material (13) is 130% or more. The ratio of the thickness of the core material to the thickness of the sheath material (13) occupied in the entire part of the plastic card is set to 20 to 53: 10. Otherwise, a breaking elongation of the core material (12) is 50 % or less and the tensile strength of the sheath material (13) is 100 MPa or more. The ratio of the thickness of the sheath material (13) to the thickness of the core material (12) occupied in the entire part of the card is set to 41 to 90: 10.

Abstract: The swelling in the surface of an IC card due to occluded pneumatic foams is eliminated by providing a novel IC card, which is comprised of a substrate mounting an IC chip and an antenna circuit, and wherein the substrate is sandwiched at least between a pair of films, and the pair of the films are provided with an uneven pattern made of small grooves formed at least on one surface thereof opposing the substrate.

Abstract: The swelling in the surface of an IC card due to occluded pneumatic foams is eliminated by providing a novel IC card, which is comprised of a substrate mounting an IC chip and an antenna circuit, and wherein the substrate is sandwiched at least between a pair of films, and the pair of the films are provided with an uneven pattern made of small grooves formed at least on one surface thereof opposing the substrate.