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 of a pitting recording type, to which recording marks are formed by irradiation with a violet laser beam having a wavelength ? in the range of about 380 to about 450 nm, includes a substrate having a surface provided with guide grooves and lands, and a metal recording layer in which recording marks are formed by irradiation with a laser beam. The guide grooves and the lands meet conditions expressed by: ?/18?DG??/11??(1) 1.5?WG/WL?3.5??(2) Where ? is the wavelength of the laser beam used for writing and reading, DG, is the depth of the grooves, WG is the width of the grooves, and WL is the width of lands formed on the substrate, and the wavelength ? is in the range of 380 to 450 nm.

Abstract: An optical recording medium includes a substrate, a protective layer and a plurality of information recording layers between the substrate and the protective layer and capable of recording data in the plurality of information recording layers and reproducing data recorded in the plurality of information recording layers by projecting a laser beam via a light incidence plane constituted by one of the surfaces of the substrate and protective layer onto the plurality of information recording layers, each of the information recording layers other than a farthest information recording layer from the light incidence plane including two recording films, a first dielectric film located on the side of the light incidence plane with respect to the two recording films and containing an oxide as a primary component and added with nitrogen, and a second dielectric film located on the opposite side of the light incidence plane with respect to the two recording films and having a lower thermal conductivity than that of the

Abstract: Recording marks are formed in a recording layer by irradiation with a laser beam. The recording layer is made of an In-base alloy containing Ni and/or Co in a content in the range of 20 to 65 at %. Another recording layer is made of an In-base alloy containing Ni and/or Co, and containing at least one of Sn, Bi, Ge and Si in a content of 19 at % or below excluding 0 at %. An optical recording medium is provided with either of the foregoing recording layers. A sputtering target is used for forming the recording layer. The recording layer of the optical recording medium has a high reflectivity (initial reflectivity), a high C/N ratio and a low jitter.

Abstract: Disclosed herein is a recording film for an optical recording medium, in which recording marks are to be formed by irradiation with a laser beam. The recording film is made of an In-base alloy containing either of an In—Ni alloy and an In—Co alloy or both the In—Ni alloy and In—Co alloy in a content in the range of 1 to 50% at. and nitrogen. The In—Ni alloy preferably has a nitrogen content in the range of 5 to 14% at. and the In—Co alloy preferably has a nitrogen content in the range of 5 to 20% at.

Abstract: An optical recording medium of a pitting recording type, to which recording marks are formed by irradiation with a violet laser beam having a wavelength ? in the range of about 380 to about 450 nm, includes a substrate having a surface provided with guide grooves and lands, and a metal recording layer in which recording marks are formed by irradiation with a laser beam. The guide grooves and the lands meet conditions expressed by: ?/18?DG??/11 ??(1) 1.5?WG/WL?3.5 ??(2) Where ?is the wavelength of the laser beam used for writing and reading, DG, is the depth of the grooves, WG is the width of the grooves, and WL is the width of lands formed on the substrate, and the wavelength ? is in the range of 380 to 450 nm.

Abstract: The optical recording medium is an optical recording medium having at least one information layer including a recording film, characterized in that the recording film is formed by a phase change material including at least Sb, Ge and Mg as main components.

Abstract: Disclosed herein is an optical information recording medium and a recording film for the optical information recording medium, which are capable of readout of short recording marks at a higher C/N ratio than the conventional BD (as in the case of the Super-RENS disk) by means of the same readout power as for the conventional BD, which is lower than that for the Super-RENS disk (or the conventional BD). To be specific, the readout power is 0.3 mW, the short recording marks have a length of 149 nm, and the C/N ratio is no less than 45 dB. The recording film is capable of information recording and reading out to and from recording marks upon irradiation with a laser beam having a wavelength of 380-450 nm, the recording marks including short recording marks having a recording length no longer than 149 nm, and has a refractive index of 1.8-2.5 and an extinction coefficient of 2.3-2.9 both for a laser beam having a wavelength of 380-450 nm.

Abstract: An information recording method enables the precise formation of a recording mark on a recording layer having a high light transmittance such as an L1 layer of a double-layered optical recording medium. The information recording method uses the following recording strategy. A laser beam is pulse-modulated so as to create a pulse series including a write pulse of a recording power and a cooling pulse of a base power. Data to be recorded is modulated to have a length of a recording mark along a track of the recording layer. At the same time, the length of the recording mark is made to correspond to an integral multiple nT of T where T is one clock cycle. An nT recording mark corresponding to nT is recorded by using the same number of write pulses and cooling pulses when n is 4 or larger. Moreover, an average width AveTc for a single cooling pulse width Tc is set to satisfy: 1.0<AveTc/T<1.6 and a total pulse width SumTc of the used cooling pulses is set to satisfy: 0.5?SumTc/nT?0.8.

Abstract: An optical recording medium includes a support substrate and two information recording layers, an information recording layer close to a light incidence plane through which a laser beam is projected including a first dielectric film, a second dielectric film and a recording layer disposed between the first dielectric film and the second dielectric film and a thickness of each of the first dielectric film and the second dielectric film being determined so as to be equal to or larger than D21 and equal to or smaller than D22, where D21 is smaller than D2, D22 is larger than D2, and D21 and D22 are determined in such a manner that the dependency X of light transmittance of the information recording layer close to the light incidence plane on the wavelength of a laser beam is smaller than 1.

Abstract: A method for recording data in an optical recording medium which can record data in information recording layers other than an information recording layer farthest from a light incidence plane of an optical recording medium including a plurality of information recording layers in a desired manner and reproduce data from information recording layers other than the information recording layer farthest from the light incidence plane in a desired manner.

Abstract: An optical recording medium includes a substrate, a light transmission layer and a plurality of recording layers between the substrate and the light transmission layer and capable of recording data in the plurality of recording layers and reproducing data recorded in the plurality of recording layers by projecting a laser beam via the light transmission layer onto the plurality of recording layers, at least one recording layer other than a farthest recording layer from the light transmission layer including a reflective film containing Ag as a primary component and C as an additive. In the thus constituted optical recording medium, recording characteristics and reproducing characteristic of the respective recording layers can be improved.

Abstract: An optical information recording medium includes a substrate and a recording layer arranged on or above the substrate, configured to bear recording marks upon irradiation of energy beams, and containing a tin-based alloy. The optical information recording medium further includes at least one dielectric layer adjacent to the recording layer, and the at least one dielectric layer mainly includes at least one oxide of an element selected from silicon, magnesium, tantalum, zirconium, manganese, and indium.

Abstract: An optical recording medium includes a substrate, a light transmission layer and a plurality of recording layers between the substrate and the light transmission layer and capable of recording data in the plurality of recording layers and reproducing data recorded in the plurality of recording layers by projecting a laser beam via the light transmission layer onto the plurality of recording layers, at least one recording layer other than a farthest recording layer from the light transmission layer among the plurality of recording layers including a first recording film containing Si as a primary component and a second recording film located in the vicinity of the first recording film and containing Cu as a primary component. In the thus constituted optical recording medium, it is possible to record data in a farthest recording layer from the light transmission layer and reproduce data from the farthest recording layer in a desired manner.

Abstract: A multilayer optical recording medium is provided with a totally reflective first information layer provided on a substrate and a second information layer being a translucent information layer provided via a spacer layer. The second information layer is composed of a TiO2 layer, a first dielectric layer, a reflective film, a second dielectric layer, a recording film, and a third dielectric layer, all of which are laminated together in this order. The first dielectric layer is made of ZrO2, Cr2O3, and Al2O3, and has a refractive index in the range of 1.84 to 2.20. If the recoding film is made of a material containing Sb as a main component, it is possible to strike a balance between high values of both the transmittance and the degree of modulation in recording information by laser light with a wavelength of 405 nm using an optical recording system having an optical system with a numerical aperture NA=0.85.

Abstract: [Object]In order to provide an optical recording medium having an excellent repetitive overwrite property even when the optical recording medium includes a plurality of information layers stacked on a substrate through at least a transparent intermediate layer, and the information layers other than the farthest one from a light incident surface of a laser beam among a plurality of information layers include a recording film formed of a phase transition material having an Sb-based eutectic crystal structure.

Abstract: The optical recording medium is an optical recording medium having at least one information layer including a recording film, characterized in that the recording film is formed by a phase change material including at least Sb, Ge and Mg as main components.

Abstract: An information recording method enables the precise formation of a recording mark on a recording layer having a high light transmittance such as an L1 layer of a double-layered optical recording medium. The information recording method uses the following recording strategy. A laser beam is pulse-modulated so as to create a pulse series including a write pulse of a recording power and a cooling pulse of a base power. Data to be recorded is modulated to have a length of a recording mark along a track of the recording layer. At the same time, the length of the recording mark is made to correspond to an integral multiple nT of T where T is one clock cycle. An nT recording mark corresponding to nT is recorded by using the same number of write pulses and cooling pulses when n is 4 or larger. Moreover, an average width AveTc for a single cooling pulse width Tc is set to satisfy: 1.0<AveTc/T<1.6 and a total pulse width SumTc of the used cooling pulses is set to satisfy: 0.5?SumTc/nT?0.8.

Abstract: An optical recording medium includes a substrate and a recording layer in which data can be recorded by projecting a laser beam thereonto, the recording layer including a first recording film containing an element selected from the group consisting of Si, Ge, C, Sn, Au, Zn and Cu as a primary component and a second recording film containing Cu as a primary component. The thus constituted optical recording medium has an excellent initial recording characteristic and can store recorded data in a good condition over the long term.

Abstract: A method for recording data in an optical recording medium according to present invention is constituted so that data are recorded in an optical recording medium including a light transmission layer and two recording layers by projecting a laser beam whose power is pulse-like modulated between a recording power and a bottom power lower than the recording power onto the optical recording medium from a side of the light transmission layer and forming recording marks having different lengths in the recording layers and that when a recording mark having a longer length than that of the shortest recording mark is to be formed in the recording layers by modulating the power of a laser beam using a single pulse, a time of raising the power of the laser beam to the recording power is delayed relative to a time of raising the power of the laser beam to the recording power when the shortest recording mark is to be formed.