Abstract: A surface treatment of a light transmissive layer by spin coating is carried out in a simple way at low cost. When a light transmissive layer is to be formed by spin coating, the transfer of an information recording layer is carried out using a resin stamper having a convex portion in an outer peripheral portion. At the same time, an inclined plane (concave portion) is formed on the side of a substrate (member on which transfer is performed). As a result, coating is achieved in such a manner that a raise in the outer peripheral portion is prevented from being noticeable.

Abstract: The invention provides an optical recording disk, with which the worsening of jitter can be prevented effectively even when fingerprints become adhered onto a laser light incidence surface. An optical recording disk 10 comprises a substrate 2, a recording layer 5, formed on the substrate, a light transmitting layer 7, formed on the recording layer, and a hard coat layer 8, formed on the light transmitting layer, and is characterized in that, when an operation of adhering an artificial fingerprint solution onto the optical recording disk's light incidence surface, onto which laser light is made incident, is performed and then an operation of wiping off the artificial fingerprint solution that has been adhered onto the light incidence surface is repeated five times, jitter becomes no more than 1.15 times that prior to the adhesion of the artificial fingerprint solution.

Abstract: A method is provided for preparing an optical information medium comprising a disk-shaped supporting substrate having a center hole, an annular information recording area thereon, and an annular resin-based light-transmitting layer on the information recording area through which recording/reading laser beam is transmitted. In the formation of the light-transmitting layer, a coating fluid containing an actinic radiation-curable resin is fed onto the supporting substrate having the information-recording area formed thereon and the supporting substrate is rotated for spreading the coating fluid over the supporting substrate to thereby form a resin layer, and subsequently, the resin layer is irradiated with actinic radiation to thereby cure said resin layer while reducing the rotation speed of the supporting substrate. This method is capable of suppressing the size of the bump formed in the outer peripheral region of the light-transmitting layer.

Abstract: A method of manufacturing a multiplayer optical recording medium by depositing two recording layers, with a spacer layer sandwiched therebetween, on a substrate. The method includes using a rubber chuck which can undergo elastic deformation at least in radial directions to close a central mounting hole of the substrate to thereby fix the substrate having the recording layer formed thereon on a turntable. After a coating liquid for forming the spacer layer is dropped in the vicinity of a boundary portion between a peripheral surface of the rubber chuck and the substrate, the rubber chuck is caused to chuck a stamper for forming the first recording layer thereon while allowing the stamper to be placed over the substrate. Thereafter, the turntable is rotated to spin-coat the coating liquid. This makes it possible to form a spacer layer having a uniform layer thickness while preventing intrusion of air bubbles, without leading to high manufacturing costs.

Abstract: A multilayer optical recording medium includes a substrate that has grooves for tracking purposes formed on a surface thereof on an incident side for a laser beam, the guide grooves having a recording layer formed on a surface thereof, and a spacer layer that has grooves for tracking purposes formed on a surface thereof, the guide grooves having another recording layer formed on a surface thereof and the spacer layer being formed above the substrate. The respective guide grooves are formed deeper the closer the grooves are positioned to the substrate. By doing so, it is possible to maintain a high signal level for a tracking error signal during a tracking servo for the recording layer that is susceptible to the effects of the thickness distribution of the spacer layer. Accordingly, it is possible to favorably perform the recording and reading of data on the recording layer in the same way as the recording and reading of data on the recording layer.

Abstract: A multi-layered optical recording medium (1) comprising a plurality of sets of at least a recording layer (L1) formed of an inorganic material and a resin layer formed of an energy-beam curable resin as an overlaying layer of the recording layer (L1) on a base (D) with a fitting center hole (H) formed in a center part. The recording layer (L0) except the recording layer (L1) immediately adjacent to the base (D) are formed so that the inner circumferential edge of a cover layer (C), an upper layer, having a larger inner diameter than that of a spacer layer (SP), a lower layer, is located on the outside of the inner circumferential edge of the recording layer (L0) in a range of 2 mm to 15 mm inclusive.

Abstract: The present invention provides a method for manufacturing an optical recording medium by forming a light-transmitting layer employing a photo-curable resin, yet affording superior mechanical properties. The present invention also provides an apparatus for manufacturing an optical recording medium suitable for use in the above-mentioned method. A method for manufacturing an optical recording medium (1) having, on a supporting substrate (2), at least one recording layer (5) and a light-transmitting layer (7) on the recording layer (5), comprising the steps of providing an energy ray-curable resin layer on the recording layer (5), and irradiating the resin layer with an energy ray at least twice to form the light-transmitting layer (7).

Abstract: An optical recording medium including a substrate and a light transmitting layer provided on the substrate so as to have a smaller thickness than that of the substrate, which is hardly warped and excellent in electrical characteristics and productivity, is provided. An optical recording medium includes: a substrate; and a light transmitting layer having a smaller thickness than that of the substrate. In this medium, a material of the substrate is an olefin maleimide copolymer.

Abstract: An optical recording medium including a substrate and a light transmitting layer provided on the substrate so as to have a smaller thickness than that of the substrate, which is hardly warped and excellent in electrical characteristics and productivity, is provided. An optical recording medium includes: a substrate; and a light transmitting layer having a smaller thickness than that of the substrate. In this medium, a material of the substrate is a polyether imide resin.

Abstract: The present invention provides a method of manufacturing an optical recording medium having two recording layers on a supporting substrate and an optical recording medium obtained according to the method.

Abstract: A multi-layer information medium wherein layer-specific information unique to the particular layer has been adequately recorded, and delay in the access to the recorded data associated with reading of the layer-specific information is suppressed. Such multi-layer information medium is also provided at low cost. The optical information medium has at least two information-storing layers each storing recorded information and/or tracking servo information, and at least one of the information-storing layers is a data layer storing recorded information, and at least one of said information-storing layers is recorded or read by the recording beam or the reading beam which has passed through other information-storing layer(s), and in this medium, the data layer has layer-specific information unique to the particular data layer recorded therein.

Abstract: The method of manufacturing a multilayer optical recording medium according to this invention is a method of manufacturing a multilayer optical recording medium, having two recording layers deposited, with a spacer layer sandwiched therebetween, on a substrate (D1) formed with a central mounting hole (1a). In forming the spacer layer between a second recording layer (L1) and a first recording layer, the substrate (D1) which has a fitting protrusion (D1a) formed around the central mounting hole (1a) is fixed to a turntable (12) in a state where a center pin (12c) of the turntable (12) is inserted through the central mounting hole (1a). After a coating liquid (R) is dropped onto the substrate (D1) at a predetermined location radially outward of the fitting protrusion (D1a), the stamper (21) is placed over the substrate (D1) while fitting a fitting groove (21b) and the fitting protrusion (D1a) to each other. Then, the turntable (12) is caused to rotate to thereby spin-coat the coating liquid (R).

Abstract: An increase in cost is minimized while realizing larger capacity.

Abstract: An optical recording disk includes a support substrate, grooves and lands alternately formed on one major surface of the support substrate, an optical functioning layer formed on the one major surface of the support substrate on which the grooves and the lands are formed and including a recording layer and a light transmission layer formed on the optical functioning layer, the grooves and the lands being formed so that the depth Gd of each of the grooves is equal to or larger than 15 nm and equal to or smaller than 25 nm and the half width Gw is equal to or larger than 150 nm and is equal to or smaller than 230 nm, and the recording layer including a first recording film containing Si as a primary component and a second recording film containing Cu as a primary component.

Abstract: The method of manufacturing an optical recording medium, according to the present invention, is a method of manufacturing an optical recording medium, in which a resin layer is formed by spin-coating a coating liquid (R) on a substrate (D) having a central portion thereof formed with a central mounting hole (1a), and the method comprises causing a rubber chuck (14) that is capable of being elastically deformed at least in radial directions and thereby closing the central mounting hole of the substrate, to undergo elastic deformation to perform chucking, whereby the substrate (D) is fixed to the turntable (12), and after dropping the coating liquid (R) onto a central portion of the rubber chuck (14), causing the turntable (12) to rotate to thereby spin-coat the coating liquid (R). This makes it possible to reliably and easily form excellent resin layer while enhancing productivity.

Abstract: An optical recording medium includes a support substrate, a light transmission layer and a recording layer located between the support substrate and the light transmission layer and containing an organic dye as a primary component, the light transmission layer including a first light transmission film located on the side of the recording layer and having Vickers hardness of 30 mgf/&mgr;m2 to 50 mgf/&mgr;m2 with respect to a load of 200 mgf and a second light transmission film located on the side of a light incidence plane through which a laser beam enters.

Abstract: An optical information medium is provided. The medium comprises a supporting substrate, an information recording layer thereon, and a light-transmitting layer thereon and a recording or reading laser beam enters the recording layer through the light-transmitting layer, and in such medium, recording/reading characteristics are improved when the beam spot of a laser beam has a small diameter and the linear velocity is high with the function of the light-transmitting layer to protect the information recording layer maintained at a sufficient level. Also provided is a medium wherein storage stability is improved.

Abstract: An optical recording medium includes a substrate and a plurality of recording layers laminated via at least intermediate layers, at least one of the recording layers other than a recording layer farthest from a light incidence plane among the plurality of recording layers containing at least one metal M selected from a group consisting of Ni, Cu, Si, Ti, Ge, Zr, Nb, Mo, In, Sn, W, Pb, Bi, Zn and La and an element X which can combine with the metal M upon being irradiated with a laser beam for recording data, thereby forming a crystal of a compound of the element X with the metal M. According to the thus constituted optical recording medium, it is possible to record data in and reproduce from a farthest recording layer from a light incidence plane in a desired manner and it is possible to record data in and reproduce from recording layer(s) other than the farthest recording layer from the light incidence plane in a desired manner.

Abstract: An optical recording medium includes a substrate, a protective layer, three or more information recording layers formed between the substrate and the protective layer and transparent intermediate layers each formed between neighboring information recording layers and capable of recording data in the three or more information recording layers and reproducing data recorded in the three or more information recording layers by projecting a laser beam onto the three or more information recording layers via a light incidence plane constituted by the surface of either the substrate or the protective layer, wherein neighboring transparent intermediate layers facing each other across an information recording layer have different thicknesses. According to the thus constituted optical recording medium, it is possible to reduce interlayer cross-talk.

Abstract: A method is provided for preparing an optical information medium comprising a disk-shaped supporting substrate having a center hole, an annular information recording area thereon, and an annular resin-based light-transmitting layer on the information recording area through which recording/reading laser beam is transmitted. In the formation of the light-transmitting layer, a coating fluid containing an actinic radiation-curable resin is fed onto the supporting substrate having the information-recording area formed thereon and the supporting substrate is rotated for spreading the coating fluid over the supporting substrate to thereby form a resin layer, and subsequently, the resin layer is irradiated with actinic radiation to thereby cure said resin layer while reducing the rotation speed of the supporting substrate. This method is capable of suppressing the size of the bump formed in the outer peripheral region of the light-transmitting layer.