Abstract: To provide an optical recording medium including a substrate and over the substrate at least a recording layer that can record and reproduce with laser light in a blue wavelength region, wherein the recording layer includes Bi and O as main components, further includes at least any of C and N, and does not include Fe; or an optical recording medium including a substrate and over the substrate at least a recording layer that contains, as main components, Bi oxide, and a simple substance of each of one or more elements M (except Bi, C, and N) that enhance a light absorption function for a recording and reproducing laser light, wherein the optical recording medium can record and reproduce with laser light in a blue wavelength region, is provided.

Abstract: To provide a sputtering target for preparing a recordable optical recording medium characterized by comprising Bi and B and a manufacturing method thereof, a recordable high density optical recording medium using the sputtering target, and a sputtering target which is capable of improving a speed of the film formation for the improvement of productivity, which has a high intensity at the time of the film formation and which has a heightened packing density.

Abstract: To provide a sputtering target for preparing a recordable optical recording medium characterized by comprising Bi and B and a manufacturing method thereof, a recordable high density optical recording medium using the sputtering target, and a sputtering target which is capable of improving a speed of the film formation for the improvement of productivity, which has a high intensity at the time of the film formation and which has a heightened packing density.

Abstract: To provide a sputtering target for preparing a recordable optical recording medium characterized by comprising Bi and B and a manufacturing method thereof, a recordable high density optical recording medium using the sputtering target, and a sputtering target which is capable of improving a speed of the film formation for the improvement of productivity, which has a high intensity at the time of the film formation and which has a heightened packing density.

Abstract: A disclosed multilayer optical information medium includes three or more information layers. Address information indicating positions in each of the information layers is recorded in a helical manner. The information layers comprise at least one I to O layer in which values representing addresses in the address information increase from an inner perimeter section toward an outer perimeter section, and at least one O to I layer in which the values representing the addresses in the address information increase from the outer perimeter section toward the inner perimeter section. All of the I to O layers have substantially the same address information and all of the O to I layers have substantially the same address information. Layer specifying information specifying the information layer is attached to the address information.

Abstract: To provide an optical recording medium including a substrate and over the substrate at least a recording layer that can record and reproduce with laser light in a blue wavelength region, wherein the recording layer includes Bi and O as main components, further includes at least any of C and N, and does not include Fe; or an optical recording medium including a substrate and over the substrate at least a recording layer that contains, as main components, Bi oxide, and a simple substance of each of one or more elements M (except Bi, C, and N) that enhance a light absorption function for a recording and reproducing laser light, wherein the optical recording medium can record and reproduce with laser light in a blue wavelength region, is provided.

Abstract: Provided is a recordable optical recording medium that comprises a substrate, a recording layer, and a reflective layer, wherein the recording layer and the reflective layer are formed on the substrate, the recording layer is formed of an inorganic material, and information is recorded on the recordable optical recording medium by use of an irreversible change at the recording layer caused by irradiating blue laser light.

Abstract: A recording method including: recording on a write-once-read-many optical medium capable of recording and reproducing with a blue laser by CAV, ZCLV, or PCAV, wherein a laser emission pattern including a recording pulse comprises two or more different levels of recording power, and a laser emission time standardized by the laser emission pattern and reference clock is fixed regardless of a recording linear velocity.

Abstract: An optical recording medium containing a substrate and a recording layer over the substrate, wherein the recording layer primarily contains Bi and O, and further contains B and at least one element X selected from Ge, Li, Sn, Cu, Fe, Pd, Zn, Mg, Nd, Mn and Ni, and a sputtering target containing Bi, B and at least one element X selected from Ge, Li, Sn, Cu, Fe, Pd, Zn, Mg, Nd, Mn and Ni.

Abstract: A write-once-read-many optical recording medium is disclosed that includes a support substrate; a recording layer on the support substrate, the recording layer containing an oxide of one of a metal and a metalloid as a principal component; and a layer adjacent to the recording layer. The recording layer includes a region where a constituent element of the adjacent layer is dispersed. Recording and reproduction are performable with laser light of a blue wavelength region.

Abstract: Disclosed is a method for manufacturing an optical information recording medium. The method includes laminating plural layers successively on a substrate having a through-hole at its center; and fitting center caps each having a predetermined radius in the through-hole to form at least two of the plural layers by a spin coat method. A radius of a first center cap used for forming an upper layer of the at least two layers is larger than a radius of a second center cap used for forming a lower layer thereof.

Abstract: To provide a sputtering target used for the formation of a recording layer of a recordable optical recording medium, wherein the sputtering target contains Bi and Fe and the packing density of the sputtering target is greater than 96%, and a recordable optical recording medium manufactured by using the sputtering target, which the recordable optical recording medium is capable of high-density recording even in the blue laser's wavelength range.

Abstract: An optical recording medium including a first substrate, multiple information layers in which each of the multiple information layers except for an information layer located at a furthermost back relative to the side of laser beam irradiation includes a recording layer, an upper protective layer and an optical adjustment layer having an absorption index k of from 0.05 to 0.20 to a light having a wavelength of 405 nm arranged in this order from the side of laser beam irradiation; and intermediate layers provided between the multiple information layers.

Abstract: The present invention provides a write-once-read-many optical recording medium comprising a substrate, a recording layer comprising any one of bismuth and an oxide of bismuth, an overcoat layer and a reflective layer in this order from a laser beam incident plane, wherein the write-once-read-many optical recording medium has a reflectivity of 35% or less when a laser is applied to the flat part of the substrate or a write-once-read-many optical recording medium comprising a substrate, an undercoat layer, a recording layer comprising any one of bismuth and an oxide of bismuth, an overcoat layer and a reflective layer in this order from a laser beam incident plane, wherein the write-once-read-many optical recording medium has a reflectivity of 35% or less when a laser is applied to the flat part of the substrate.

Abstract: For recording information at high density even at blue-laser wavelengths, a write-once-read-many optical recording medium includes a first inorganic thin film and at least one of a second inorganic thin film and an organic thin film, in which the first inorganic thin film contains at least “R” and “O,” wherein “R” is at least one selected from Y, Bi, In, Mo, V and lanthanum series elements; and “O” is oxygen atom, and the second inorganic thin film and the organic thin film are capable of suppressing at least one of deformation and breakage of the first inorganic thin film and receiving the change of state of the first inorganic thin film.

Abstract: A recording/reproduction method for recording/reproducing data to/from an optical recording medium including a guiding groove and a recording layer is disclosed. The recording/reproduction method includes a step of irradiating a laser beam onto the optical recording medium by modulating at least one of a laser irradiation time and a laser irradiation intensity to two or more values, wherein a Pbi/Pr ratio of a reproduction power (Pr) and a bias power (Pbi) is set to a value that is no less than 0.5, wherein the data are recorded by constantly providing the laser beam with a power level including the reproduction power (Pr) added to the bias power (Pbi).

Abstract: To provide a dual-layer recordable optical recording medium, including: a first information layer; intermediate layer disposed over the first information layer; and second information layer disposed over the intermediate layer, the first information layer, intermediate layer, and second information layer being sequentially deposited from a laser irradiation side, wherein the first information layer comprises, from the laser irradiation side, at least a thin film containing Bi as a main ingredient, dielectric layer, reflective layer and thermal diffusion layer, and the second information layer comprises, from the laser irradiation side, at least a thin film containing Bi as a main ingredient, dielectric layer and reflective layer, and wherein the ratio of the thickness of the dielectric layer of the second information layer (t2) to the thickness of the dielectric layer of the first information layer (t1), t2/t1, is in a range of 0.7 to 1.5 or 4.5 to 6.0.

Abstract: To provide a sputtering target for preparing a recordable optical recording medium characterized by comprising Bi and B and a manufacturing method thereof, a recordable high density optical recording medium using the sputtering target, and a sputtering target which is capable of improving a speed of the film formation for the improvement of productivity, which has a high intensity at the time of the film formation and which has a heightened packing density.

Abstract: To provide a sputtering target used for the formation of a recording layer of a recordable optical recording medium, wherein the sputtering target contains Bi and Fe and the packing density of the sputtering target is greater than 96%, and a recordable optical recording medium manufactured by using the sputtering target, which the recordable optical recording medium is capable of high-density recording even in the blue laser's wavelength range.

Abstract: A write-once-read-many optical recording medium enabling excellent recording and reproducing properties at a wavelength of blue-laser wavelengths or shorter, i.e. 500 nm or less, particularly at wavelengths of near 405 nm and high density recording. To this end, a write-once-read-many optical recording medium of the invention comprises a recording layer using a material represented by BiOx (0<x<1.5), in which a recorded mark comprises crystal of Bi and/or crystal of a Bi oxide. Another write-once-read-many optical recording medium comprises a recording layer which comprises Bi, oxygen, and M (M represents at least one element selected from Mg, Al, Cr, Mn, Co, Fe, Cu, Zn, Li, Si, Ge, Zr, Ti, Hf, Sn, Mo, V, Nb, Y, and Ta), in which a recorded mark comprises crystal of the elements contained in the recording layer and crystal of an oxide of the elements.