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: To provide an optical recording medium exhibiting favorable write/read characteristics in high-speed recording. In an optical recording medium including a reflective layer, a dye-containing recording layer, and a transparent resin layer on a substrate in this order, a barrier layer is disposed between the recording layer and the resin layer, where the barrier layer comprises a material having a bulk thermal conductivity M of 70 W/m·K or more at 300 K and has a thickness t less than 5 nm.

Abstract: A silver alloy reflective film is used in an optical information recording medium and contains silver as a main component, a total of 0.01 to 3 atomic percent of at least one of Bi and Sb, and a total of 3 to 42 atomic percent of at least one of Cu, Ge, Mg, and Zn. The silver alloy reflective film preferably further contains 0.1 to 3 atomic percent of yttrium. An optical information recording medium includes the silver alloy reflective film. A sputtering target for depositing the silver alloy reflective film contains silver as a main component, 0.01 to 3 atomic percent of Sb (or 0.03 to 10 atomic percent of Bi), and a total of 3 to 42 atomic percent of at least one of Cu, Ge, Mg, and Zn.

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: In an information recording medium comprising at least a substrate, a recording layer, and a resin layer, the substrate is formed with at least a pit corresponding to a read only area 31 and a groove corresponding to a recording/reproducing area 32 without overlapping with each other. A reflectivity of the recording layer is specified to be more than 10%. The recording layer and the resin layer are continuously adhered over both the read only and recording/reproducing areas 31 and 32. The information recording medium is characterized in that both push-pull signal outputs T1 and T2, which are reproduced from the read only area 31 and the recording/reproducing area 32 respectively, are more than 0.1 and satisfy an inequality 1.5?T1/T2?0.5.

Abstract: The present invention relates to an Ag alloy film. Particularly, it is preferably used as a reflective film or semi-transmissive reflective film for an optical information recording medium having high thermal conductivity/high reflectance/high durability in the field of optical information recording media, an electromagnetic-shielding film excellent in Ag aggregation resistance, and an optical reflective film on the back of a reflection type liquid crystal display device, or the like. The Ag alloy film of the present invention comprises an Ag base alloy containing Bi and/or Sb in a total amount of 0.005 to 10% (in terms of at %). Further, the present invention relates to a sputtering target used for the deposition of such an Ag alloy film.

Abstract: A write once optical recording medium has an inorganic recording film which includes an oxide film having germanium oxide (GeO) as a principal component, and a metal film adjacent to the oxide film, the metal film having a titanium/silicon alloy (TiSi) as a principal component. According to this arrangement, it is possible to construct an inexpensive write once optical recording medium with large strength capable of high density recording by using a short wavelength light source and an optical system with a high numerical aperture having excellent characteristics.

Abstract: Materials for optical recording media are disclosed. Specifically, the materials are metal chelate compounds of azo dyes, which are formed from sulfamoylated m-diaminobenzene compounds and benzene ring-containing azo compounds. Further, the invention provides an optical recording medium, characterized in that said metal chelate compounds of azo dyes are employed onto the optical recording medium to form a recording layer. The invention also discloses a process for the production of an optical recording medium.

Abstract: Provided is a sputtering target material which has a high reflectance and which is excellent in a sulfurization resistance, comprising an Ag alloy prepared by alloying Ag with a specific small amount of the metal component (A) selected from In, Sn and Zn, a specific small amount of the metal component (B) selected from Au, Pd and Pt and, if necessary, a small amount of Cu.

Abstract: A two-layered optical recording medium which includes a first substrate, a first information layer, a second information layer, and a second substrate formed in this order as viewed from the light beam irradiation side, the first information layer includes a first lower dielectric layer, a first recording layer, a first upper dielectric layer, a first reflective layer, and an inorganic dielectric layer formed in this order as viewed from the light beam irradiation side; the second information layer includes a second lower dielectric layer, a second recording layer, a second upper dielectric layer, and a second reflective layer formed in this order as viewed from the light beam irradiation side; and the first reflective layer is made of Cu with a content of 99.8% by mass to 95.0% by mass and one or more metals selected from Ta, Nb, Zr, Ni, Cr, Ge, Au, and Mo.

Abstract: An optical recording medium using Sn as the recording material to improve the jitter is provided, in which on the surface of a disc substrate 11 where a concave and convex shape dividing a track area is formed, are formed on the surface of the concave and convex shape a first protective layer 31 for protecting at least an optical recording layer 31, an optical recording layer 12 using a chemical compound at least composed of tin (Sn), nitrogen (N) and oxygen (O), formed on the first protective layer, a second protective layer 32 for protecting this optical recording layer, formed on this optical recording layer, and a light-transmittable layer 13 formed on the second protective layer; with this structure, the optical recording layer 12 under high temperature and high humidity can be stabilized by means of the first and second protective layers 31 and 32.

Abstract: An optical disc includes an optical disc; a thermally conductive material disposed in a pattern of discrete pads on said disc; and a thermochromic material disposed over said pattern of thermally conductive material. A method of making an optical disc includes indenting a pattern onto an insulator; and depositing a thermally conductive material into indents of said pattern.

Abstract: A transfer layer on a surface of a mold has a thickness distribution along the radius direction that the layer is thick in an inner round portion but is gradually thinner toward an outer round portion. An adhesive layer is formed between a surface of a signal substrate which bears a signal recording film and the mold which seats the transfer layer. The adhesive layer has a thickness distribution that the layer is thin in an inner round portion but is gradually thicker toward an outer round portion. Since the thickness distributions along the radius direction of the transfer layer and the adhesive layer are opposite to each other, the thickness distribution of an isolation layer which comprises the two layers is uniform.

Abstract: An optical information recording medium includes at least a reflecting layer, an optical information recording layer, a super-resolution layer and a protective layer. The super-resolution layer is a thin layer whose an optical constant changes nonlinearly due to a red shift of its band gap, and made of solid solution, compound or mixture of metal oxides containing two or more types of metal ions of the same valence. Ion radius unconformity ?R=|(RMi?RMj)/RMj| between ion radii RMi and RMj of two types of metal ions Mi and Mj arbitrarily selected from the two or more types of metal ions is 8% or less. The difference ?E=Eg?E between band gap energy Eg of the mixture of the metal oxides and energy E corresponding to a wavelength of the laser beam is a more 0.4 or less 1.4 eV.

Abstract: A recording medium of the recordable type in the form of a multi-layer disc or the like which is improved in compatibility and feasibility in use and a recording apparatus and a recording method ready for the recording medium are disclosed. A region for recording interlayer folding back position information is set on the recording medium (for example, “End sector number in Layer 0” or a session item type 3). In response to a fact that recording on a certain recording layer reaches a maximum recording range or that data recording advances from a certain recording layer to a next recording layer, interlayer folding back position information is recorded on the recording medium. This signifies that such recording is performed when advancement of the data recording to another recording layer is performed at a stage prior to disc closing or session closing or when it is predicted that such advancement of the data recording occurs soon.

Abstract: The present invention provides a solid material comprising an immobilized mixture of two or more proteorhodopsins, two or more bacteriorhodopsins, or one or more bacteriorhodopsin and one or more proteorhodopsins. The proteorhodopsins are selected from the group consisting of all-trans-retinal-containing proteorhodopsins and retinal analog-containing proteorhodopsins; all of which have absorption spectra that do not overlap. The bacteriorhodopsins are selected from the group consisting of all-trans-retinal-containing bacteriorhodopsins and retinal analog-containing bacteriorhodopsins; all of which have absorption spectra that do not overlap. The present invention also provides an optical information carrier, such as an optical data storage material and a fraud-proof optical data carrier, comprising the above-described solid material and a substrate selected from the group consisting of glass, paper, metal, fabric material, and plastic material, wherein said solid material is deposited on said substrate.

Abstract: A phase change recording medium comprising an as-deposited first recording layer configured to undergo a reversible phase change between an amorphous state and a crystalline state due to light irradiation and thereby change an optical characteristic. The as-deposited first recording layer includes a plurality of fine nuclei having an average size of 0.5 nm to 4 nm in the amorphous state.

Abstract: The present invention provides a reversible thermosensitive recording medium including a support and a thermosensitive recording layer thereon, in which the thermosensitive recording layer comprises an electron-donating coloring compound and an electron-accepting compound, and the thermosensitive recording layer is capable of forming a relatively developed condition and a relatively erased condition depending on at least one of the difference of heating temperatures and the difference of cooling rates following to heating, and in which the electron-accepting compound comprises a phenol compound represented by the General Formula (1): where, in the General Formula (1) “l” represents an integer of 1 to 3, “m” represents an integer of 1 or more, and “n” represents an integer of 7 or more.

Abstract: A reversible thermosensitive recording medium including a substrate, and a thermosensitive layer including an electron donating coloring compound, an electron accepting compound, and a phenol anti-oxidation agent containing one or more sulfur atoms having an alkyl group on one side. In addition, the thermosensitive layer reversibly changes its color tone depending on temperature to reversibly record and erase an image thereon.

Abstract: An information recording medium of the present invention includes a substrate and an information layer arranged on the substrate. The information layer includes a recording layer that is changed in phase reversibly between a crystalline phase and an amorphous phase by at least one of optical means and electrical means, and at least one crystalline nucleation layer that contains at least one element selected from Bi and Te and at least one element (M1) selected from Sc, Y, La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Yb, and Lu and is provided in contact with the recording layer.

Abstract: A multilayer optical recording medium including a first recording layer for recording or reproducing information by using a first light beam having a center wavelength ?1, a first photochromic layer provided on the first recording layer, and a first optical waveguide layer provided on the first photochromic layer for guiding to the first photochromic layer a second light beam having a center wavelength ?2 different from the center wavelength ?1. The multilayer optical recording medium further includes a second recording layer provided on the first optical waveguide layer for recording or reproducing information by using the first light beam, a second photochromic layer provided on the second recording layer, and a second optical waveguide layer provided on the second photochromic layer for guiding the second light beam to the second photochromic layer. The first and second photochromic layers become transparent to the first light beam by irradiation with light or by application of heat.

Abstract: A Flexible VCD Having Domed Center and Method of Making Thereof is disclosed. The disc will has a flat data storage section of its substrate that is less than 0.7 millimeters thick, while the central region of the disc is defined by a dome structure adjacent to the spindle aperture that is of standard digital disc thickness. The disc is thin enough such that its substrate is flexible. The dome structure is shaped to provide the widest compatibility with player/recorders, as well as with disc printing systems. Disc versions are available that provide conical dome structures, as well as slivered dome structures of both conical and rectangular cross-section. The method for manufacturing the discs simply requires the replacement of the conventional stamper holder with a stamper holding having a non-flat face.

Abstract: A Flexible VCD Having Domed Center and Method of Making Thereof is disclosed. The disc will has a flat data storage section of its substrate that is less than 0.7 millimeters thick, while the central region of the disc is defined by a dome structure adjacent to the spindle aperture that is of standard digital disc thickness. The disc is thin enough such that its substrate is flexible. The dome structure is shaped to provide the widest compatibility with player/recorders, as well as with disc printing systems. Disc versions are available that provide conical dome structures, as well as slivered dome structures of both conical and rectangular cross-section. The method for manufacturing the discs simply requires the replacement of the conventional stamper holder with a stamper holding having a non-flat face.

Abstract: A super-resolution information storage medium having recording marks or pits that are smaller than the resolution limit of a beam incident from an information recording and/or reproducing apparatus, and the information recording and/or reproducing apparatus. The information storage medium includes a substrate and at least one super-resolution reproduction layer containing a super-resolution material and a high melting point material with a melting point higher than that of the super-resolution material formed on the substrate. The high melting point material suppresses movement of the super-resolution material in a melted phase so as to prevent signal degradation caused by repeated reproduction.

Abstract: In a write-once optical information recording medium including a substrate, a groove-shaped track such as a guiding groove, and an optical recording layer containing an organic dye material and disposed on the guiding groove, wherein information is recorded by irradiating a short-wavelength laser beam from a surface of the optical recording layer opposite the substrate, and the information can be reproduced by reading a change in the reflected light of a short-wavelength laser beam after the information recording, an unrecorded portion of the optical recording layer has a lower reflectance than a pit portion formed after recording to a portion of the optical recording layer, the optical recording layer has a refractive index n in the range of about 1.2 to about 2.1 before recording and an extinction coefficient k in the range of about 0.01 to about 0.7 before recording, and n+k is in the range of about 1.4 to about 2.1.

Abstract: An irreversible optical recording medium comprises at least a substrate whereon is arranged at least a photosensitive layer comprising a structured front face destined to receive an optical radiation during data recording and/or reading operations. The medium also comprises a track comprising raised zones, having: a height comprised between about 25 nm and about 35 nm for widths of raised zones comprised between 250 nm and 370 nm, and a height comprised between a minimum value varying substantially linearly, in decreasing manner, from 25 nm to 32 nm, and a maximum value substantially of 35 nm, for widths of raised zones comprised between 200 nm and 250 nm.

Abstract: A multilayer phase change information recording medium including plural information layers containing at least a first information layer and a last information layer, each of which includes a recording layer in which information is recorded utilizing a phase change between a crystalline phase and an amorphous phase. At least one of the plural information layers other than the last information layer includes a first lower protective layer, a first recording layer located overlying the lower protective layer, a first upper protective layer located overlying the first recording layer, a first reflective layer located overlying the first upper protective layer, and a heat diffusion layer located overlying the first reflective layer and which mainly contains In, Zn and O.

Abstract: It is an object of the present invention to provide a phase-change information recording medium, and the like, which is easy to perform initial crystallization, exhibits good recording sensitivity at a linear velocity as high as 10 double speeds or more with as much capacity as DVD-ROM, is capable of overwrite recording and has good storage reliability. For this purpose, the phase-change information recording medium comprises a substrate and at least a first protective layer, a phase-change recording layer, a second protective layer, and a reflective layer disposed on the substrate in one of this sequence and reverse sequence wherein the phase-change recording layer comprises a composition expressed by Sn?Sb?Ga?Ge?Te??X? (In this regard, X represents at lease one element selected from Ag, Zn, In and Cu. ?, ?, ?, ?, ? and ? represent composition ratio (atomic percent) of each element and are expressed as 5???25, 40???91, 2???20, 2???20, 0???10, 0???10 and ?+?+?+?+?+?=100).

Abstract: Imaging layers, image recording media, and methods of preparation of each, are disclosed.

Abstract: The optical information recording medium comprises a recording layer on a surface of a support. The surface of the support has pregrooves with a track pitch ranging from 50 to 500 nm, and the recording layer comprises a phthalocyanine derivative denoted by general formula (I) and a compound denoted by general formula (II). In general formula (I), R1 denotes a substituent, n denotes an integer ranging from 1 to 16, and M denotes a metal atom optionally comprising a ligand, a metal oxide, or two hydrogen atoms. In general formula (II), R2 denotes a substituted or unsubstituted alkyl group having 1 to 18 carbon atoms or a substituted or unsubstituted aryl group having 4 to 24 carbon atoms, and m is an integer ranging from 1 to 4.

Abstract: The optical information recording medium comprises a recording layer on a surface of a support. The surface of the support has pregrooves with a track pitch ranging from 50 to 500 nm, the recording layer comprises an azo metal complex dye, the azo metal complex dye is a complex of one or more azo dye and transition metal ions of which number is equal to or greater than the number of the azo dye. The azo metal complex dye comprises two or more transition metal ions per molecule, and in a molecule of the azo metal complex dye.

Abstract: An optical information recording medium includes a substrate formed in a concave-convex state by providing pits or grooves corresponding to recorded information, used for optically reproducing the information by irradiation of a light beam, and may also include a recording layer. The optical information recording medium includes a temperature responsive layer whose reflectance and/or transmittance for the light beam changes with a change in temperature caused by the irradiation of a light beam. With such an arrangement, the present invention provides an optical information recording medium enabling secure and highly accurate reproduction of information recorded with high density, and the recording and reproduction methods thereof.

Abstract: A multi-layer structure whose volume changes when a temperature exceeds a predetermined threshold value, a microscopic structure drawing method that involves emitting a laser beam onto the multi-layer structure to create a temperature distribution within a beam spot and performing microscopic recording on a portion of the beam spot having a temperature higher than the threshold value, an optical disc master, and a mastering method using the same, where the multi-layer structure includes a substrate and a transformation layer formed on the substrate, wherein a volume of a portion of the transformation layer irradiated by a laser beam changes when the temperature of the portion exceeds a predetermined temperature. The microscopic structure drawing method includes emitting the laser beam onto a predetermined region of the transformation layer and heating the region of the transformation layer irradiated by the laser beam beyond a predetermined temperature so that the heated region can undergo a volume change.

Abstract: A recording medium has at least a recording layer on a transparent substrate. The recording layer has at least a first phase-changeable film and a second phase-changeable film in that order, starting on the side closest to the transparent substrate. The first phase-changeable film and the second phase-changeable film each contains at least 10 atom % and no more than 50 atom % germanium and at least 45 atom % and no more than 60 atom % tellurium. Also at least one of the phase-changeable films contains bismuth.

Abstract: An information medium includes a reflective layer with Ag as a main constituent, a sulfide species dielectric layer, and a recording layer in the mentioned order on a surface of a substrate. Data is recorded and reproduced by emitting a laser beam from an opposite side of the recording layer to the substrate. A barrier layer with an oxide of Zn as a main constituent is formed between the reflective layer and the sulfide species dielectric layer.

Abstract: There is disclosed a minute structure including a sulfur compound and a silicon oxide. There is also disclosed a write-once information recording medium including a substrate and a recording layer formed of a mixed inorganic material and deposited on the substrate, wherein the mixed inorganic material contains a sulfur compound and a silicon oxide.

Abstract: A liquid material containing a silicone material or organosilica is applied to a roughly polished surface of a polycrystalline silicon substrate to form a smooth thin film covering steps and grain boundary portions; thereafter, the thin film is subjected to a heat treatment at an appropriate temperature to allow the organic components thereof to evaporate off, thereby forming an SiO2 film; and the resulting SiO2 film is then subjected to precision polishing, such as a CMP process, to impart the substrate with a high planarity. This method makes it possible to give a planar and smooth surface with no effect reflecting differences in crystal orientation among polycrystalline grains or the presence of grain boundaries. The Si substrate for magnetic recording media thus obtained exhibits a sufficient impact resistance and an excellent surface planarity.

Abstract: The invention relates to a method and a device according to the preambles of claims 1 and 10, and also to the use of a nanopatterned die, a disc with a defined nanopattern and a hard disk drive comprising a disc of this type. In order to propose a more rapidly operating device as well as a corresponding method in which the smallest-possible patterns can be applied to discs, and in order to provide discs, which are produced as cost-effectively as possible, for hard disk drives, said discs having smaller patterns and thus being able to be produced rapidly and cost-effectively, the invention proposes using microcontact printing (?CP) in the production of micropatterned and/or nanopatterned products/substrates of this type.

Abstract: A write once optical recording medium includes a substrate on which an oxide film serving as an inorganic recording film is formed, the oxide film being made of a recording material of an oxide Ge1Ox (x is an atomic number ratio) of germanium (Ge) and a composition of Ge1Ox of the oxide film being specified so as to satisfy 1.0<x<2.0.

Abstract: A dual-layer optical recording medium, which is formed by adhering a disk substrate (inverted-stack structure) formed by stacking a reflective layer (1) and a recording layer (1) on a substrate (1) and a disk substrate (conventional-stack structure) formed by sequentially stacking a recording layer (2) and a reflective layer (2) on a transparent substrate (2) with a transparent resin layer interposed therebetween, is prepared such that the transparent resin layer has a product obtained by multiplying the thickness by the elastic modulus at 25±5° C. falling within the range of not less than 2.0×104 MPa·?m to not more than 30.0×104 MPa·?m, resulting in suppressing excessive deformation involving an adjacent track portion produced by recording optical information in the recording layer (1) of the inverted-stack structure, thereby reducing crosstalk and providing satisfactory recording and/or reading characteristics in high-speed recording applications.

Abstract: An optical recording medium containing a cyanine dyes of formula: Where at least one pair of R1 & R2 and R3 & R4 are benzyl moieties, rings A and B are each a benzene or naphthalene ring, Y1 and Y2 are C 1-30 organic groups and Anm? is an m valent anion, present in an integer p.

Abstract: The present invention provides an optical information recording medium of excellent signal quality in high density recording onto a semitransparent information layer, its manufacturing method and a manufacturing apparatus. The optical information recording medium of the present invention includes at least a semitransparent information layer disposed between a circular transparent substrate and a protective substrate, in which the information layer has spiral grooves for guiding a light beam, and also includes a recording film capable of recording/reproducing information thereon/therefrom by changing at least in two states detectable optically by irradiation of the light beam from the transparent substrate side, and the difference in film thickness of slope portions of the inner circumferential side and outer circumferential side of the groove is within ±10% in the entire region for recording/reproducing information.

Abstract: An optical disk and a method of producing it, particularly a stamper for molding a semiconductor disk base capable of forming an optical disk sufficiently compatible with commercially available CD (Compact Disk) players, a method of producing a stamper, a method of producing an optical disk base, a method of producing an optical disk, and an optical disk base and optical disk are disclosed. The present invention improves both of transferability and tact of an optical disk base molding cycle, allows a fine pattern to be formed in a transfer surface, and makes it needless to change existing molding equipment. In addition, when guide grooves formed in the optical disk are filled with a pigment by spin coating, the guide grooves have a substantially uniform configuration in the radial direction of the disk. The optical disk is sufficiently compatible with various CD players available on the market.

Abstract: An information recording medium wherein an optically detectable information recording medium is comprised of at least a substrate, a recording layer, and a resin layer. The information recording medium has surface roughness R? on the surface of the recording layer, which is in contact with the resin layer, under 5 nm. The information recording medium controls the reproduction signal noise, enables highly densified recording.

Abstract: The present invention relates to an Ag alloy film. Particularly, it is preferably used as a reflective film or semi-transmissive reflective film for an optical information recording medium having high thermal conductivity/high reflectance/high durability in the field of optical information recording media, an electromagnetic-shielding film excellent in Ag aggregation resistance, and an optical reflective film on the back of a reflection type liquid crystal display device, or the like. The Ag alloy film of the present invention comprises an Ag base alloy containing Bi and/or Sb in a total amount of 0.005 to 10% (in terms of at %). Further, the present invention relates to a sputtering target used for the deposition of such an Ag alloy film.

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 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: The invention relates to novel optical recording media, which comprise particular novel metal chelates and have an excellent recording and playback quality, especially at a wavelength of from 300 to 500 nm.

Abstract: An object of the invention is to provide an optical film product that is configured such that the direction of an optical axis can be easily recognized and that markings do not interfere with a defect inspection and to provide a method for producing such an optical film product. The invention is directed to an optical film product, including: an optical film layer having an optical axis; a surface protection film that is laminated on the optical film layer to protect the surface of the optical film layer; and an optical axis information part that shows information about the optical axis and is interposed between the optical film layer and the surface protection film.

Abstract: A multi-layer-information-recording medium is applied to an information recording and reproducing apparatus capable of recording or reproducing information on and from either of a single-layer-information-recording medium having a single recording layer on one side, and a multi-layer-information-recording layer having a plurality of recording layers layered on a spacer layer on one side as a change in reflectivity by irradiating a light beam. The multi-layer-information-recording medium is compatible in terms of at least reproducing and recording with a single-layer-information-recording medium having a cover layer having a predetermined refractive index “n” and a thickness “t” disposed on a recording layer on a light incident side surface. The multi-layer-information-recording medium includes a deepest recording layer deepest from the light incident side surface. The deepest recording layer is formed at an optical distance d1 from the light incident side surface satisfying an equation d1=nt.