Abstract: According to one embodiment, a stamper has three-dimensional patterns in a dummy region. The three-dimensional patterns have a repeatable run out of 1 nm or less between the 15th and 40th orders when the rotational frequency is the first order as a reference.

Abstract: According to one embodiment, an optical recording medium is provided in which interlayer crosstalk is low and in which stable and high-quality recording characteristics can be obtained. To this end, an optical recording medium comprises a first recording part which includes a first recording layer and a first light reflecting layer and which is disposed on a side closer to a light receiving surface, and a second recording part which includes a second recording layer and a second light reflecting layer and which is disposed on a side farther from the light receiving surface, the first recording part and the second recording part being stacked, wherein the thickness of the second light reflecting layer is larger than the thickness of the first light reflecting layer.

Abstract: According to one embodiment, an optical recording medium is provided in which interlayer crosstalk is low and in which stable and high-quality recording characteristics can be obtained. To this end, an optical recording medium comprises a first recording part which includes a first recording layer and a first light reflecting layer and which is disposed on a side closer to a light receiving surface, and a second recording part which includes a second recording layer and a second light reflecting layer and which is disposed on a side farther from the light receiving surface, the first recording part and the second recording part being stacked, wherein the thickness of the first light reflecting layer is smaller than the thickness of the second light reflecting layer.

Abstract: According to one embodiment, a recordable information recording medium includes an organic dye layer contains an organic dye including a cation portion having monomethinecyanine and an anion portion having an azo metal complex, and a quencher having a formazan metal complex.

Abstract: According to one embodiment, a write-once information recording medium includes a transparent resin substrate having concentric or spiral grooves and lands, and a recording film formed on the grooves and lands of the transparent resin substrate, wherein the recording film includes an organic dye layer containing a metal complex monomer and a metal complex polymer, a recording mark is formed in the organic dye layer by emission of a short-wavelength laser beam, and a light reflectance of the recording mark formed by emission of the short-wavelength laser beam is higher than that before emission of the short-wavelength laser beam, and the grooves wobble within a predetermined amplitude range.

Abstract: According to one embodiment, a write-once type information storage medium using a recording material which has a low to high characteristic that a light reflectivity in a recording mark increases with respect to a non-recording area and which has a recording characteristic in accordance with a principle of recording without substrate deformation, wherein the recording material includes at least an organic metal complex, and wherein the organic metal complex includes a center metal.

Abstract: According to one embodiment, an information recording medium includes a transparent resin substrate having concentric grooves and concentric lands or a spiral groove and spiral land, and a recording layer formed on the groove and land, and capable of recording and reproducing information by using a semiconductor laser of 450 nm or less. When reproducing recorded information, the information recording medium satisfies the following formula (1) 0.87?M4×/M1×?1.

Abstract: There are provided a mounting unit configured to selectively mount first and second optical disks in which characteristics of recording films are different from one another, and a discriminating unit configured to discriminate which of the first and second optical disks is mounted on the mounting unit based on a level of a reproduction signal which is obtained by reproducing innermost peripheral portion of the first or second optical disk mounted on the mounting unit.

Abstract: According to one embodiment, an information recording medium including a recording film using an organic recording material recorded by recording light having a wavelength of 405 nm and an organic recording material whose light reflection quantity varies by reproducing light having a wavelength of 650 nm for a recording layer and an optical reflection layer and a land sandwiched between a pre-groove having an irregular shape and an adjoining pre-groove is provided on an interface between the recording layer and the optical reflection layer.

Abstract: According to one embodiment, an information recording medium has a plurality of recording layers, and records and reproduces information by using a semiconductor layer of 450 nm or less. When reproducing information, letting x be the frequency of repetitive recording of a shortest mark length and shortest space length of the information, the ratio of the value of a highest level to the value of a level at x/190 of a sum signal detected within the frequency range of x/3240 to x/190 is lower than 32 dB, or the ratio of the average value of the amplitudes of signals of repetitive recording of the shortest mark length and shortest space length to the value of the highest level within the frequency range of x/3240 to x/190 is higher than 10 dB.

Abstract: According to one embodiment, when recording information by using a semiconductor laser at 450 nm or less, an information recording medium satisfies 9.5×10?8??/(X*NA)?4.6×10?8 (where X is the linear recording velocity, ? is the laser wavelength, and NA is the numerical aperture).

Abstract: According to one embodiment, an information storage medium has a substrate, a first recording layer containing an organic dye material, a first barrier layer, a spacer layer, a second recording layer, a second barrier layer, and a protective layer formed on the second barrier layer. The angle that the outer side surface and inner side surface of the protective layer make with a direction parallel to the surface of the second barrier layer is 30° to 150°, at least one of the first and second barrier layers has lands and grooves on its two major surfaces and the depth of the lands on one major surface is smaller than that of the lands on the other major surface close to the substrate, or the first and second barrier layers are made of a material formable by coating.

Abstract: According to one embodiment, an information recording medium has two or more recording layers, the track pitch falls within the range from 250 to 500 nm, and the half maximum full-width of the groove of the substrate falls within the range from 47.5% to 72.5%.

Abstract: According to one embodiment, in a multilayered write once information recording medium, the light reflectance of a recording mark formed in a first recording film by irradiation with a short-wavelength laser beam is higher than a light reflectance before irradiation with the short-wavelength laser beam, the light reflectance of a recording mark formed in a second recording film by irradiation with the short-wavelength laser beam is higher or lower than a light reflectance before irradiation with the short-wavelength laser beam, and the light reflectance of a recording mark formed in a third recording film, which is arbitrarily formed, by irradiation with the short-wavelength laser beam is higher or lower than a light reflectance before irradiation with the short-wavelength laser beam.

Abstract: According to one embodiment, an information recording medium has a first substrate, first recording layer, second recording layer, and second substrate. The first recording layer has a first dye layer and first reflecting layer from the light incidence side. The second recording layer has a second dye layer and second reflecting layer from the light incidence side. The thickness of the second dye layer is larger than that of the first dye layer.

Abstract: According to one embodiment, in an information recording medium in which letting H1 (nm) a groove depth of a first substrate on which a first recording layer is formed, H2 (nm) a groove depth of a second substrate on which a second recording layer is formed, H11 (nm) a thickness of a first dye layer at a land area, H12 (nm) a thickness of the first dye layer at a groove bottom area, H21 (nm) a thickness of a second dye layer at a land area, and H22 (nm) a thickness of the second dye layer at a groove bottom area, the groove depth H1 of the first substrate and the groove depth H2 of the second substrate satisfy |H11?H12|=?, |H21?H22|=?, ?/8n?H1????/3n, and ?/8n?H2????/3n.

Abstract: According to one embodiment, a first recording film, interlayer, and second recording film are formed on a transparent resin substrate having a groove and land. A recording mark is formed by irradiation with a short-wavelength laser beam. The light reflectance of the recording mark formed by irradiation with the short-wavelength laser beam is higher than a light reflectance before irradiation with the short-wavelength laser beam. The first recording film has a first read-only recording mark recorded by a three-dimensional pit. The second recording film has a second read-only recording mark recorded by a three-dimensional pit. The reflectances of the pits of the first and second recording layers are 4.2% to 8.4%, or the pit width of the second recording film is larger than that of the first recording layer.

Abstract: According to one embodiment, an information recording medium has two or more recording layers, the track pitch falls within the range from 250 to 500 nm, and the half maximum full-width of the groove of the substrate falls within the range from 47.5% to 72.5%.

Abstract: Manufacturing of a higher quality write-once type multilayer optical disc is facilitated. The optical disc includes a plurality of recording layers in which recording or reproduction is carried out by a blue or blue-violet laser beam of a wavelength of about 405 nm. Each of the recording layers includes a recording layer which uses an organic dye. The plurality of recording layers includes a layer in which a groove pattern around a recording mark is deformed when information is recorded, and a layer in which the groove pattern around the recording mark is not deformed when information is recorded.

Abstract: According to one embodiment, an optical recording medium is provided in which interlayer crosstalk is low and in which stable and high-quality recording characteristics can be obtained. To this end, in this optical recording medium, an intermediate layer whose thickness variation is managed to be equal to or less than a predetermined value is provided between a first recording part and a second recording part.