Abstract: A disc structure for making an inverted optical response through a super-resolution process using a recorded mark portion and a space portion, which is realized to amplify a signal amplitude and solve a conventional problem that a conventional super-resolution technique can obtain only small signals, since the super-resolution area is reduced to realize high density recording of data.

Abstract: This invention provides a technique which ensures that if a recording error occurs in an optical disc, recorded data will be immediately erased from the disc without leaking to third parties. While recording data onto the optical disc, a controller judges whether the recording process has been executed to completion properly. If the recording process is judged to have failed, the controller will stop the recording process and activate an optical pickup to erase recorded data from the data-recording area on the optical disc by overwriting this area with required erasing data.

Abstract: An optical disk that includes main information and write-once information recorded on the optical disk. The write-once information is recorded as information unique to the optical disk, and the write-once information stores at least watermark production parameters for producing a watermark.

Abstract: A phase-change optical information recording medium in which information can be recorded, reproduced and rewritten and which includes a first transparent substrate having a wobbling guide groove which is spirally formed thereon at a pitch; a first dielectric layer located overlying the first transparent substrate and having an optical thickness of from 80 nm to 200 nm; a phase-change recording layer located overlying the first dielectric layer and having an optical thickness of from 20 to 50 nm when the recording layer is in an erased state; a second dielectric layer located overlying the recording layer and having an optical thickness of from 10 nm to 70 nm; a reflection layer located overlying the second dielectric layer; optionally a third dielectric layer located between the second dielectric layer and the reflection layer; and a second transparent substrate located overlying the reflection layer.

Abstract: A method for encrypting and/or hiding data to a storage device is given. The method is based on any of the following algorithms: 1. Formatting any storage uniquely while storing the information about the unique format to a Geometrical Cell Location Table (GCLT); 2. Storage-sectors, based on standard formatting are uniquely shuffled whiled creating Shuffled LBA (SLBA); 3. A method of encrypting (82) a sector-content by using more than one key (81); 4. “Dating” prevention of the sectors content in a hard disk drive by electro-magnetic instruments, this is achieved by renewing data of randomly selected sectors (83); 5. A method for keeping the encrypted content of the hard disk drive in its maximal encryption power complexity by preserving hard disk drive fully filled with encrypted data (even empty sectors are filled with encrypted data). By implementing the above algorithms to a hard disk drive, the encryption complexity power stays constant in time.

Abstract: An optical data storage and retrieval system that includes a phase change storage medium and dual energy sources. The phase change material may store information by undergoing a transformation from one structural state to another structural state through application of energy. The system is equipped with two energy sources, neither of which alone provides sufficient energy to effect the transformation. The combination of both energy sources, however, provides sufficient energy to induce the transformation needed to record information. The energy from either source may be optical, thermal, electromagnetic, mechanical or magnetic energy.

Abstract: A rewritable optical record carrier comprising a first substrate carrying a first recording stack of layers, which recording stack comprises, a first dielectric layer, a recording layer comprising a phase-change recording material, a second dielectric layer, and a metal mirror layer. In order to achieve a maximum R*M said first dielectric layer has a thickness d1 in the range of 20 nm to 50 nm, and said second dielectric layer has a thickness d2 according to the relation 0.0225*d22?2.6572*d2+173.3 (nm)<d1<0.0225*d22?2.6572*d2+213.3 (nm) when the mirror layer comprises aluminum, or a thickness d2 according to the relationship 0.0191*d22?2.0482*d2+149.6 (nm)<d1<0.0191*d22?2.0482*d2+189.6 (nm) when the mirror layer comprises silver.

Abstract: A write-once optical disc, and a method and apparatus for recording management information on the write-once optical disc, are provided. The optical disc includes at least one recording layer, and at least one SRR entry. Each SRR entry corresponds to an SRR and includes at least one status field for indicating a recording status of the corresponding SRR. The status field includes a session start flag for indicating whether the corresponding SRR is a start of a session, the session being formed by a group of the SRRs. Each SRR entry further includes a start address field indicating where the corresponding SRR starts, and a last address field indicating the last recorded address of the corresponding SRR.

Abstract: Disclosed is an optical data storage medium with enhanced contrast. The optical data storage medium includes a substrate having oppositely facing first and second surfaces. A first metal/alloy layer is formed overlaying the first surface of the substrate. The first metal/alloy layer is formed from tin, antimony and element selected from the group consisting of indium, germanium, aluminum, and zinc. After the first metal/alloy layer is formed, a first dielectric layer is formed overlaying the first metal/alloy layer. This dielectric layer is formed from silicon oxynitride. The first metal/alloy layer is positioned between the substrate and the first dielectric layer.

Abstract: A multi-stack optical data storage medium for rewritable recording by a focused laser-light beam, the medium having a substrate with deposited on aside thereof: a first recording stack comprising a phase-change type recording layer at least one further recording stack comprising a phase-change type recording layer, a transparent spacer layer adjacent each further recording stack. The further recording stack is sufficiently transmissive to ensure proper sensitivity for reading and recording in the first recording stack. For this purpose, at least one indium tin oxide layer is present in at least one of the further recording stacks. The indium tin oxide layer further ensures proper cooling behavior of the recording layer of the further recording stack in order to obtain sufficient recording performance in the farther recording stack.

Abstract: A multilayer optical information recording medium includes optical information recording layers, and dielectric multilayer reflecting layers provided under the optical information recording layers respectively. Each of the dielectric multilayer reflecting layers includes: a laminate of low refractive index films and high refractive index films; and a variable refractive index film exhibiting change of refractive index induced by laser beam irradiation. Each of the dielectric multilayer reflecting layers is provided so that reflectance of a portion used for reading/writing information by condensed laser beam irradiation is high while transmittance of the other portion is high. It is possible to reduce intensity of laser beam to be irradiated to the medium.

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: An optical information recording medium, especially a CD-RW medium, that can undergo direct overwriting at high speed is disclosed. The optical information recording medium includes a transparent substrate, at least a recording layer and a reflective layer on or above the substrate and is capable of performing at least one of recording, erasing and rewriting information by irradiating and scanning with focused light to thereby form and/or erase recording marks on the recording layer. The recording layer contains an alloy and/or an intermetallic compound mainly containing Ga, Ge, Sb, and Te in a compositional ratio represented by the following formula: GaxGey(SbzTe1-z)1-x-y wherein x, y, and z each represent an atomic ratio of a positive real number less than 1 and satisfy the following conditions: 0.02?x?0.06, 0.01?y?0.06, 0.80?z?0.86, x?y, and x+y?0.1.

Abstract: An optical information recording medium including a substrate, a light absorbing layer which is located overlying the substrate and in which marks are formed to store information and a light reflection layer located overlying the light absorbing layer including a crystal, wherein the optical information recording medium satisfies the relationship, Lt/4 ?Lc? Lm, wherein Lc represents the average particle diameter of the crystal of the light reflection layer, Lm represents the minimum length of the marks, and Lt represents the thickness of the light reflection layer.

Abstract: An information layer 0 comprises a system lead-in area, data lead-in area, data area, and middle area, an information layer 1 comprises a system lead-out area, data lead-out area, data area, and middle area, an end position of the data area of layer 1 is positioned outer than a start position of the data area of layer 0, the data lead-in area comprises a guard track zone wider than a test zone in the data lead-out area, the data lead-out area comprises a guard track zone wider than a test zone and a management zone in the data lead-in area, the middle area of layer 0 comprises a guard track zone wider than a test zone in the middle area of layer 1, and the middle area of layer 1 comprises a blank zone wider than a test zone in the middle area of layer 0.

Abstract: A method of recoding information on a reproduction-only optical information storage medium, including: forming a plurality of areas and at least one transition area on the reproduction-only optical information storage medium. Each transition area is located between two adjacent areas. The transition area allows data to be smoothly reproduced from the reproduction-only optical information storage medium at a low error generation rate. Also, since the optical information storage medium provides standards for the transition area, it is compatible with existing optical information storage media.

Abstract: A phase-change optical recording medium includes a phase-change optical recording film that permits reversible phase change between a crystalline phase and an amorphous phase upon irradiation with light, and an interface film formed of hafnium oxide, or a mixture of hafnium oxide and at least one oxide selected from the group consisting of cerium oxide, titanium oxide and zirconium oxide, and formed in contact with at least one surface of the phase-change optical recording film.

Abstract: An optical recording medium has a plurality of laminated information recording layers. The average reflectivity within a stipulated range in the unrecorded regions of at least one of the information recording layers has a value between the reflectivity in the crystalline state and the reflectivity in the amorphous state. When the focus of the laser beam is aligned to one information recording layer, the difference in reflectivity is small between the case in which those regions of the other information recording layer on which the beam spot shines is a recorded region and the case in which it is an unrecorded region, and even in the case that a boundary between a recorded region and an unrecorded region is present within the beam spot, the distribution of reflectivity within the beam spot becomes constant, so the stable recording and/or playback can be performed.

Abstract: A method for defect management of a rewritable optical disc is provided. The rewritable optical disc has a data area comprises recording units for storing a target data and a replacement area comprising first replacement units for replacing defective recording units of the data area. First, a fragmented status of the target data is calculated, wherein the fragmented status reflects a dispersion level of the first replacement units in view of a distribution of the defective recording units. The fragmented status is then compared with a threshold value to determine whether to perform a defragment operation about the target data. Finally, the defragment operation about the target data is performed by rearranging the first replacement units in accordance with the sequence of the defective recording units.

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.

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: An optical information recording medium 10 includes a first substrate 11, a second substrate 12 disposed in parallel with the first substrate 11, and an information layer 20 disposed between the first substrate 11 and the second substrate 12, and the information layer 20 includes a recording layer 23 and inorganic layers (lower side interface layer 22 and upper side interface layer 24) adjacent to the recording layer 23. The recording layer 23 is changed between at least two different states, which are discernable optically, by irradiation with a laser beam 14 incident from the first substrate 11 side. The inorganic layer contains a nitride of SixGe1-x (where 0.3?x?0.9) as a main component. The present invention provides an optical information recording medium capable of recording/reproducing information with satisfactory reliability even in recording/reproducing with a light beam having a short wavelength or in recording/reproducing with respect to a plurality of information layers.

Abstract: A maximum likelihood decoder includes metric generators for generating metrics based on a plurality of partial responses and a Viterbi decoder for realizing maximum likelihood decoding by using a synthetic metric generated by synthesizing the metrics. A first partial response is an original partial response. A second partial response is a differential response generated by subtraction by shifting the first partial response by 1 clock. Alternatively, the differential response may be generated by subtraction by shifting the first partial response by 2 clocks. The second partial response may be a response generated by addition by shifting the first partial response by 2 clocks. Alternatively, the second partial response may be an integration response generated by adding all previous samples of the first partial response.

Abstract: A method is provided for manufacturing an optical data recording medium including a plurality of data recording layers each having a user data recording region and a BCA formation region positioned at an inner position than the data recording region. The method includes: forming a first data recording layer out of the plurality of data recording layers on a first substrate; forming a second data recording layer out of the plurality of data recording layers on a second substrate; forming a BCA pattern within the BCA formation region of the second data recording layer to record burst cut data; and bonding the first and second substrates after the BCA pattern is formed.

Abstract: A light-plasmon coupling lens including an optically transparent substrate having a light incident surface and a light-plasmon coupling surface opposite the light incident surface. The light-plasmon coupling surface including at least a set of circular concentric peaks/valleys which form a Fourier sinusoidal pattern in the radial direction of the circular concentric peaks/valleys. A conformal layer of metal is deposited on the light-plasmon coupling surface of the substrate and has aperture at the center of thereof through which plasmons are transmitted. An optical recording medium including a light-plasmon coupling lens.

Abstract: An optical disk with an erasable surface of the present invention includes a transparent substrate, a recording layer, and a reflective layer, and an erasable writing layer. The recording layer is formed between the transparent substrate and the reflective layer, and the reflective layer is formed between the recording layer and the erasable writing layer. The optical disk may further include a protective layer, and the protective layer is formed between the erasable writing layer and the reflective layer. The invention also discloses a method of manufacturing such optical disk.

Abstract: A method and an apparatus for detecting a number of variation in resistance within a material stack in response to a scanning and injection of a non-contacting electron stream into a material stack, the material stack having a first conductive contact layer, a variable resistive layer, a fixed resistive layer, and a second conductive contact layer, and the variations in resistance within the material stack being based on one of a plurality of resistive states of the variable resistive layer. The method also includes generating two magnetic fields within a transformer, the transformer being operatively coupled to the first and second conductive contact layers and generating a differential output signal within the transformer based on the two magnetic fields, the differential output signal being associated with one of the plurality of resistive states.

Abstract: Plural grooves or lands formed in an information recording carrier include at least a wobbling region and data is recorded wobblingly in this wobbling region by phase shift modulation while recorded digitally with a single or multiple waves as a channel bit.

Abstract: Four types of optical systems, a polarization optical system including an objective lens having a high numerical aperture, a polarization optical system including an objective lens having a low numerical aperture, a non-polarization optical system including an objective lens having a high numerical aperture and a non-polarization optical system including an objective lens having a low numerical aperture, are selectively used at the time of irradiating light from a semiconductor laser on a target disk for measurement, and the in-plane birefringence characteristic and perpendicular birefringence characteristic of the target disk are separately acquired based on the amounts of received light obtained by measuring reflected light from the target disk by a photosensor.

Abstract: The methods described herein are directed at securing information in storage media such as optical discs, magnetic disks or a combination thereof. In particular the methods describe embedding a first stream of data in a second stream of data by modulating the location of transition edges in the second stream of data. A method for writing data to a storage medium includes the steps of representing the raw (first) data to be written to the storage medium as a sequence of bits in a format appropriate for writing to a storage medium; representing second data (supplemental data) as a second sequence of bits and writing the first sequence of bits to the storage medium as a corresponding sequence of pits along a track, wherein the location of the pits along the track represents the stored first data, and while writing the first sequence of pits, modulating the locations at which transition edges of the sequence of pits are written to embed the second data in the sequence of pits.

Abstract: A method of recording and reproducing information in a phase-change optical recording medium by irradiation of an electromagnetic wave for recording, reproducing and/or rewriting information is proposed, wherein when information is recorded in the phase-change optical recording medium by modulating an input signal and conducting pulse width modulation recording, a recording pulse string for recording and rewriting is a continuous electromagnetic wave, and a recording pulse string for recording and rewriting, after the modulation of the input signal, is an electromagnetic wave pulse string having a front-pulse portion fp, a multi-pulse portion mp with a total pulse duration period T and a duty ratio y, and an off-pulse portion op, wherein the duty ratio y is decreased as a recording linear velocity for the phase-change optical recording medium is increased, whereby multi-speed recording or CAV (constant angular velocity) recording is carried out.

Abstract: An optical information recording medium includes a recording layer for recording optical information, a plurality of laminated layers, and a substrate for supporting those layers, while a beam of a specific wavelength is being radiated, a light absorption peak is shifted to a longer or a shorter wavelength side than the peak located before said beam radiation, realizing a high S/N ratio and a high recording density of the medium.

Abstract: A method for selecting a chapter boundary for a digital video recording is provided that includes examining cut-rates for the recording. A determination is made regarding whether a default chapter length has passed. A determination is made regarding whether the cut-rate for the recording at the default chapter length is low. The chapter boundary is selected at the default chapter length when the cut-rate for the recording at the default chapter length is low.

Abstract: An optical recording medium configured with a light reflection layer; a first protection layer; a recording layer containing a phase-change material which changes between crystalline and amorphous phases by a light irradiation; a second protection layer; and one of a cover layer and a protective coating layer disposed on a substrate in this order; and in which the light reflection layer is formed of one of an Al alloy and an Ag alloy; the first protection layer has a ZnS—SiO2 mixture layer which contains a mixture of ZnS and SiO2, and a intermediate layer having higher thermal conductivity than the ZnS—SiO2 mixture layer; the intermediate layer is formed on the side of the light reflection layer; the recording layer comprises Ge, Sb, and Te as main elements; and the second protection layer comprises a mixture of ZnS and SiO2.

Abstract: Disclosed is an optical recording medium, comprising a polymer alloy forming a phase-separated domain structure of a coating object, and a volatile substance interacting with the polymer alloy. The volatile substance in a vapor state is deposited on the surface of specific phase-separated domain, and dispersedly infiltrated into the phase-separated domain. The phase-separated domain and the volatile substance chemically interact with each other. The optical recording medium is operable to perform optical recording by utilizing change in the transmittance, reflectance, refractive index or surface potential thereof in response to irradiation of ultraviolet light, visible light, or infrared light from outside. The present invention can provide an optical recording medium suitable for high-density recording in a wide wavelength range.

Abstract: A high-speed, write-once type optical recording medium, which utilizes laser light that is either blue or an even shorter wavelength, as well as an optical recording method and an optical recording apparatus for recording onto this optical recording medium. A high-speed, write-once type optical recording medium 10 having a recording layer 18 and a light transmission layer 22 formed sequentially on top of a support substrate 12, wherein the recording layer 18 is formed by laminating first and second vice-recording layers 18A, 18B which include Al and Sb respectively as primary components, and irradiation of a laser light of blue wavelength from a laser light source 24, through the light transmission layer 22 and onto the recording layer 18, causes diffusion and mixing of the Al and Sb contained within the first and second vice-recording layers 18A, 18B, and this mixing enables the formation of a recording mark based on an irreversible change in reflectance.

Abstract: A device for exciting surface plasmons includes a light illuminating source, a transparent substrate having a ridge, a metal layer covering side surfaces of the ridge and their neighboring region, and a thin metal film formed on a top face of the ridge. Evanescent waves caused by light emitted from the light illuminating source and transmitted through the transparent substrate and the thin metal film can excite surface plasmons in the thin metal film.

Abstract: It is an object of the present invention to provide an optical recording medium that is suitable for recording information therein at a high velocity. An optical recording medium according to the present invention includes a recording layer formed of a phase change material and capable of recording data therein at a linear recording velocity equal to or higher than 10 m/sec, wherein Rtop satisfies the condition that it is larger than {11?(V/5)} and smaller than {22?(2V/5)}, where Rtop (%) is a reflectivity of the crystal phase change material forming the recording layer and V (m/sec) is a target linear recording velocity. According to the present invention, since modulation (MOD) of 50% or more can be ensured, it is possible to effectively suppress the degradation of jitter caused by recording data at a high linear recording velocity equal to or higher than 10 m/sec.

Abstract: An optical recording medium and a recording system for the same are provided, which can dissipate heat produced by a laser beam during recording operations to thereby increase the erasing power margin of the laser beam which allows the playback jitter value to take on a certain value or less. A recording system 1 includes an optical recording medium 10 and an optical recording apparatus 30. The optical recording medium 10 has a reflective film 16, a second dielectric layer 18, a recording layer 20, a heat sink layer 24, and a light-transmitting layer 26, which are formed on a support substrate 12. The heat sink layer 24 is made of a material having a certain range of thermal conductivity, e.g., alumina. The optical recording apparatus 30 allows a laser beam of 450 nm or less in wavelength to be incident from the light-transmitting layer 26 via a lens system having an objective lens with a numerical aperture of 0.7 or more.

Abstract: An environmental load information of an information recording medium is recorded on the information recording medium so as to recycle or dispose properly an information recording medium, which is not necessary any more. The information recording medium comprises a main information area (102) for recording or reproducing information and a recording area (101) for environmental load information, which is recorded with an environmental load information of the information recording medium.

Abstract: An optical information recording medium which makes it possible to reduce the noise level and improve the C/N ratio. An optical information recording medium has a recording layer formed on a substrate, for having a laser beam irradiated thereto for recording and reproducing record data. The recording layer includes a first sub-recording film and a second sub-recording film. The first sub-recording film is formed of a first material containing Si as a main component. The second sub-recording film is formed of a second material containing Zn as a main component and having Al added thereto, and disposed in the vicinity of the first recording film. The laser beam is irradiated to the recording layer via a light transmitting layer formed in a manner covering the recording layer.

Abstract: An optical information recording medium is composed of at least a phase-change type recording layer 4 provided on a substrate 1. The optical information recording medium is conducted to record and erase information by changing a phase of the phase-change type recording layer by irradiating light. The phase-change type recording layer is further composed of TiwGexSbyTez, wherein each of w, x, y and z is in atomic percent and satisfies following relations: 0.5?w?4.0, 3.4?x?14.5, 2.1?y/z?4.0 and w+x+y+z=100.

Abstract: The present invention provides a music playback system which uses an interface to easily play back a characteristic musical structure section with a music audio data playback apparatus. The interface 13 includes a function of selecting an arbitrary characteristic music structure section from a plurality of characteristic music structure sections, and a function of visualizing a characteristic music structure section. The characteristic music structure section specifying data for specifying the selected arbitrary characteristic music structure section is given to a music audio data playback apparatus 3. The music audio data playback apparatus 3 changes a playback position of the music audio data to the characteristic music structure section specified by the characteristic music structure section specifying data given by a specifying data providing means 12.

Abstract: An authentication system may comprise: a first light source, a second light source, and at least three optically filtered light sensing devices. The first light source can have a first light source spectral distribution and can be capable of providing sufficient excitation to produce a photoluminescent emission from a medium comprising a luminescent tag and a color. The second light source can have a visible multi-wavelength spectral distribution and can be capable of providing sufficient visible multi-wavelength illumination of the medium to generate a second analog response. Each light sensing device can have a different device spectral sensitivity range.

Abstract: A disk with an Ag reflective layer, a recording layer including elements Sb and Te, and a dielectric layer including S provided between the reflective layer and the recording layer has the problems of corrosion of the Ag reflective layer, decline of the signal quality due to insufficient heat releasing ability, and exfoliation between the layers. (1) A phase-change optical disk includes, on a transparent substrate, a recording layer in which an optically detectable reversible change between an amorphous phase and a crystalline phase can be caused by irradiation with an energy beam, a reflective layer, and a dielectric layer arranged between the recording layer and the reflective layer, wherein the main component of the dielectric layer is an oxide or a nitrooxide of Ta.

Abstract: A main information area 31 capable of recording an information signal and a subsidiary information area 32 for recording subsidiary information that is different from the information signal are divided in one principal plane direction of a substrate, and an information layer for recording the information signal in the main information area 31 is provided also in the subsidiary information area 32, and medium identification information for distinguishing the medium optically is recorded in the information layer of the subsidiary information area 32 without changing the shape of the information layer. As a result, the medium identification information can be recorded in an optical recording medium 1 stably. In particular, the initialization of a phase change type optical recording medium and the recording of the medium identification information can be performed at the same time, so that the production process can be simplified, and the production costs can be reduced.

Abstract: A phase-change recording material used for an information recording medium utilizing a crystalline state as a non-recorded state and an amorphous state as a recorded state, which has the composition of the following formula (1) as the main component: (Sb1?xSnx)1?y?w?zGeyTewM1z??formula (1) wherein each of x, y, z and w represents atomicity, x, z and w are numbers which satisfy 0.01?x?0.5, 0?z?0.3 and 0?w?0.1, respectively, and the element M1 is at least one element selected from the group consisting of In, Ga, Pt, Pd, Ag, rare earth elements, Se, N, O, C, Zn, Si, Al, Bi, Ta, W, Nb and V, and (I) when z=0 and w=0, y is a number which satisfies 0.1?y?0.3, (II) when 0<z?0.3 and w=0, y is a number which satisfies 0.05?y?0.3, and (III) when 0?z?0.3 and 0<w?0.1, y is a number which satisfies 0.01?y?0.3.

Abstract: An optical information recording medium which makes it possible to reduce the noise level and improve the C/N ratio and store record data for a long time period. An optical information recording medium has a recording layer formed on a substrate, for having a laser beam irradiated thereto for recording and reproduction of record data. The recording layer includes a first sub-recording film and a second sub-recording film. The first sub-recording film is formed of a first material containing Si as a main component. The second sub-recording film is formed of a second material containing Al as a main component and having Mg added thereto, and disposed in the vicinity of the first recording film. The laser beam is irradiated to the recording layer via a light transmitting layer formed in a manner covering the recording layer.

Abstract: An optical information recording medium which is capable of performing high-density recording of record data, and storing the recorded data for a long time period such that the recorded data can be normally reproduced during the long time period. An optical information recording medium has a recording layer formed on a substrate, for having a laser beam irradiated thereto for recording and reproduction of record data. The recording layer includes a first sub-recording film and a second sub-recording film. The first sub-recording film is formed of a first material containing Si as the main component. The second sub-recording film is formed of a second material containing Cu as the main component and having Si added thereto, and disposed in the vicinity of the first recording film.

Abstract: When initializing first and second information layers on a phase-change optical disk of the one-side multilayered configuration, a mistake occurs depending on thin film configuration of first and second information layers. The phase-change optical disk having a plurality of information layers having at least a recording layer of generating optically detectable reversible change between an amorphous phase and a crystalline phase on a transparent substrate by irradiation of an energy beam and having an optical separation layer formed between the information layers, wherein initialization start positions of crystallizing said plurality of information layers vary by irradiating a laser beam thereon.