Abstract: A recording medium for an electrophotographic image forming apparatus is provided, including: a substrate layer, a toner receiving layer formed on one side or both sides of the substrate layer, and an outermost layer formed on the toner receiving layer, in which the outermost layer includes a thermoplastic resin incorporating with a UV absorbing unit, and a composition for forming the outermost layer. The recording medium for an electrophotographic image forming apparatus has excellent light resistance and discoloration resistance, while maintaining good gloss.

Abstract: An objective is to provide a positive-working planographic printing plate material exhibiting scratch resistance useful for high productivity in large size printing, and excellent sensitivity and development latitude against a developer having a low pH or a worn-out inactive developer, as well as a method of preparing a planographic printing plate employing the planographic printing plate material. Also disclosed is a positive-working planographic printing plate material possessing a support and provided thereon, a light-sensitive layer, wherein the light-sensitive layer possesses a compound containing a residue of a cyclic ureide compound having a cyclic structure having at least two amide bonds (—NHCO—) in a cycle.

Abstract: A silver-based alloy thin film is provided for the highly reflective or the semi-reflective layer of optical discs. Alloy additions to silver include magnesium, gold, rhodium, ruthenium, osmium, platinum, palladium, copper, silicon, cadmium, tin, lithium, nickel, cobalt, manganese, indium, chromium, antimony, gallium, boron, molybdenum, zirconium, beryllium, titanium, aluminum, germanium and zinc. These alloys have moderate to high reflectivity and reasonable corrosion resistance in ambient environments.

Abstract: The present invention relates to materials comprising hydrophilic polymers and immobilized proteorhodopsin and the use of such materials as an optical information carrier. The material comprises one or more hydrophilic polymers that are capable to form a homogeneous phase with proteorhodopsin prior to solidification to a solid form. The hydrophilic polymer, for example, is silica sol-gel, gelatin, polyvinylalcohol, agarose, agar, methyl cellulose, polyvinyl acetate, polyvinyl pyrrolidone, polyethylene glycol, or a mixture thereof. The solid material having immobilized proteorhodopsin is deposited on a substrate selected from the group consisting of glass, paper, metal, fabric material, plastic material, and used as an optical data storage material or a fraud-proof carrier. The present invention further provides a security ink comprising proteorhodopsin and one or more hydrophilic polymers.

Abstract: An optically readable media (10) has an information-encoding layer (16) and at least one color-forming layer (12) that embodies an optical readout-limiting mechanism. In a first embodiment the at least one color-forming layer contains an additive that does not interfere with the optical readability of the media for a duration of a readout period. The additive, upon exposure to a source of optical radiation that is suitable for reversing the color-forming layer from an optical readout inhibiting state to an optical readout enabling state, undergoes a transformation that maintains the color-forming layer in the optical readout inhibiting state. More specifically, exposure to the source causes the color-forming layer to photobleach and the additive to oxidize, where the oxidation of the additive permanently inhibits the optical readability of the media. The additive may be a leuco dye.

Abstract: In an optical recording medium having two recording layers of a first recording layer and a second recording layer, the second recording layer contains metallized azo dyes represented by the following general formula (I) or (II), and recording characteristics of the second recording layer are improved by having optical density of 1.3 times as large as, or 1.3 times greater than, that of a dye contained in the first recording layer. (In this regard, rings A1 and A2 are nitrogen-containing heteroaromatic rings, rings B1 and B2 are aromatic rings, and X is alkyl group substituted by at least two fluorine atoms).

Abstract: A medium includes a plurality of Fabry-Perot cavities of varying depths. The cavities correspond to different colors which are produced by the respective cavities under incident light. A thermo-sensitive material covers the plurality of cavities. The cavities are selectively exposed by heating portions of said thermo-sensitive material to alter the thermo-sensitive material where heated thereby forming an image.

Abstract: A first optical information recording medium comprises a first WORM-type recording layer on which information is recorded by irradiation with a laser light having a wavelength of 440 nm or less, and a cover layer having a thickness of 0.01 to 0.5 mm, formed in this order on a first substrate having a thickness of 0.7 to 2 mm. Specifically, for example, a first light reflection layer, the first WORM-type recording layer, a barrier layer, a first adhesion layer, and the cover layer are formed in this order on the first substrate. The first WORM-type recording layer comprises at least one azo dye. The azo dye has an —N?N— group and a pyrazole ring bonded thereto, and contains no metal atoms or metal ions in the molecule.

Abstract: An optical information recording medium having a recording layer on which information can be recorded by irradiation with a laser light having a wavelength of 440 nm or less, wherein the recording layer contains at least one azo-metal complex dye derived from a metal ion or a metal oxide ion and an azo dye represented by the following general formula (1-1) or (1-2): wherein Q represents a carbocyclic group or a heterocyclic group, and R6 to R8 independently represent a hydrogen atom or a substituent.

Abstract: An information recording medium includes an insulating member, first and second electrodes formed in one plane of the insulating member, and a conductive layer having an electrochromic material providing continuity with the first and second electrodes. A gap between the first and second electrodes is insulated.

Abstract: An optical recording medium comprises a transmission substrate and a recording layer formed on the transmission substrate, the recording layer containing at least a dye material expressed by a general formula shown at the following chemical formula (in the chemical formula 1, R1 represents alkyl group having carbon numbers 1 to 4, R2, R3 represent alkyl group having carbon numbers 1 to 4, benzyl group or groups combined to form 3 to 6 rings, Y1 and Y2 independently represent organic groups and X represent ClO4, BF4, PF6, SbF6) and a dye material expressed by a general formula represented by the following chemical formula 2(in the chemical formula 2, R1 and R2 represent alkyl groups having carbon numbers 1 to 4, benzyl groups or groups combined to form 3 to 6 rings, Y1, Y2 independently represent organic groups and X represent ClO4, BF4, PF6, SbF6): In a write once type optical recording medium such as DVD?R and DVD+R, satisfactory recording characteristics can be obtained from low-speed recording to high-

Abstract: For improving the jitter property and ensuring the high reliability of an optical disk, a metal film containing phosphorus is disposed in a reflective layer. The layer has a hardness of 60 mgf/?m2 or more as nano indentation hardness, and an adhesive layer used for bonding has a glass transition temperature of 100° C. or higher but 200° C. or lower, an elastic modulus at 25 to 80° C. of 1000 MPa or more, and an adhesion strength of 4N or more. The dye for the dye recording layer has a water solubility of 20% or less as measured as light absorbance of hot water in which the dye recording layer is soaked.

Abstract: An organic dye type optical recording medium capable of recording or reading information by a blue laser having a shorter wavelength, is provided. An optical recording medium comprising a substrate and a recording layer capable of recording or reading information by a laser, formed on the substrate, characterized in that the recording layer contains a compound represented by the following formula (1): wherein each of R1 to R6 which are independent of one another, is a hydrogen atom or a linear or branched alkyl group which may be substituted, each of k and n which are independent of each other, is an integer of from 0 to 2, provided 0?k+n?4, each of l and m which are independent of each other, is 0 or 1, provided 1?l+m?2, each of rings A and B which are independent of each other, is an aromatic ring which may have optional substituents, provided that such optional substituents may be bonded to each other to form a ring.

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: Squarylium-metal chelate compounds as recording materials for optical recording media, and optical recording media using these compounds, which have excellent recording properties, light resistance and storage stability. The squarylium-metal chelate compound is represented by following Structural Formulas (1) and (2): In the formula (1), M represents a metal atom capable of coordinating; “a”, “b” and “c” each represents a squarylium dye ligand of formula (2), where “a” is different from “b”; and “c” may be the same as or different from “a” or “b”; and “m” represents 0 or 1. In the formula (2), R1 and R2 are the same or different and each represents an alkyl group, aralkyl group, aryl group or heterocyclic group, each of which may be substituted; and X represents an aryl group which may be substituted, a heterocyclic group which may be substituted, or Z3=CH—, wherein Z3 represents a heterocyclic group which may be substituted.

Abstract: Polymeric material suitable for the preparation of optical recording media for volume data storage is disclosed. The molecular structure of the material contains a main chain derived from any of poly(meth)acrylate, poly(meth)acrylamide, polysiloxane, polyurea, polyurethane, polyester, polystyrene and cellulose, and the side chains contain a) azobenzene dye, b) form anisotropic grouping, and c) at least one monomer selected from the group consisting of where R=H or methyl, R? and R? independently denote CnH2n+1 or CnH2n-OH and R?? denotes —CnH2N—OH.

Abstract: An optical information recording medium whose recording layer includes a phthalocyanine derivative having a substituent of the following formula (I): (in the formula (I), R1, R2 and R3 each independently represent a substituent other than a hydrogen atom). A dye compound represented by the following formula (II): (in the formula (II), M represents a metal or a metal oxide each of which may have a ligand. R4, R5 and R6 each independently represent a substituent other than a hydrogen atom, and n is an integer of from 1 to 8).

Abstract: A write-once optical recording medium has a transparent resin substrate having a concentric groove or a spiral groove and having recessed cells defining recording regions that are arranged in the groove, a recording film comprising an organic dye formed to fill the cells, and a metal reflection film formed on the recording film.

Abstract: Optical disks include machine readable data that is written with dye that is invisible to the naked eye and a laser-imagable coating that forms marks that are visible to the naked eye.

Abstract: An optical recording medium having an organic dye layer as a recording layer on a substrate, wherein at least one benzobisazole-based compound represented by a general formula (1) is contained in the recording layer: (wherein substituents X and Y each independently represent an aryl group or a heteroaryl group, rings A and B each independently represent an oxazole ring or a thiazole ring, and Q1 and Q2 each independently represent a hydrogen atom, a halogen atom or an alkyl group, with a proviso that, aryl group(s) or heteroaryl group(s) represented by the substituents X and Y each independently may be substituted by a halogen atom, a hydroxyl group, a cyano group, an amino group or a substituted or unsubstituted alkyl, aralkyl, aryl, alkenyl, alkoxy, aralkyloxy, aryloxy, alkenyloxy, alkylthio, aralkylthio, arylthio, alkenylthio, mono-substituted amino, di-substituted amino, acyl, alkoxycarbonyl, aralkyloxycarbonyl, aryloxycarbonyl, alkenyloxycarbonyl, mono-substituted aminocarbonyl, di-substituted aminoc

Abstract: A compound used as storage medium of high-density optical disc is disclosed, which has structure represented as following formula: wherein each A1, A2, A3, and A4 independently is selectively substituted aryl or heteroaryl, said aryl or heteroaryl is selectively substituted by one or multiple functional groups; R1 and R2 independently is H, halogen, alkyl or aryl; B is Ar or n is an integral ranging from 1 to 4; and n? is an integral ranging from 0 to 4.

Abstract: In one embodiment, a limited play optical storage medium for data comprises: a reflective layer, a control portion comprising an optically transparent polymeric resin and a light absorbing material, wherein the control portion has a light transmission of greater than or equal to about 70% at 650 nm, a curing index of greater than or equal to about 0.1 and a filtration index of greater than or equal to about 2.5, and wherein the light absorbing material has a minimum extinction coefficient (measured in CH2Cl2 solution) at 600 nm of greater than or equal to 1,500 mol?1·cm?1·L, a maximum extinction coefficient (measured in CH2Cl2 solution) at 650 nm of less than about 1,000 mol?1·cm?1·L, a ratio of extinction coefficient at 650 nm to 600 nm less than about 0.

Abstract: An optical storage medium having a three-dimensional data pattern, and fabrication method thereof. The optical storage medium includes a substrate and a plurality of recording layers, each constituting a fluorescent oligomer. Due to the high quantum yield and high stock shift of the fluorescent oligomer, the recording layers emit intensive fluorescent signals when the optical storage medium is illuminated with reading beams. Accordingly, the recording sensitivity and the readout characteristics of optical storage mediums are improved without additional signal-amplifying structures or materials.

Abstract: Methods and apparatus are provided for making an optically readable storage media in which the reading beam passes through a bonding layer configured with a reactive material that transforms from an optically transparent state to an optically opaque state after exposure to a predefined stimulus, thereby inhibiting access to the data encoded on the optically readable storage media. The method includes steps of synthesizing a blocked dye combining the blocked dye with a carrier material curing the resultant combination deblocking the dye to produce a reduced dye in the resultant bonding layer exposing the optically readable storage media with the reactive material in its bonding layer to a predetermined stimulus. In a further aspect of the present invention methods and apparatus are provided for making an optically readable storage media wherein the reading light passes through the bonding layer and the data encoded information is encoded on the L1 substrate.

Abstract: An optical recording material for binary, multibit or volume data storage is described. The optical recording material comprises: (a) at least one dyestuff selected from polymeric azo dyestuffs and oligomeric azo dyestuffs, the dyestuff changing its spatial arrangement upon irradiation with polarized electromagnetic radiation; and (b) optionally at least one grouping having form anisotropy.

Abstract: Block polymers suitable for the preparation of data storage media are disclosed. The media produced of the inventive of the polymers has thickness in the range of a few millimeters. In contrast with currently available materials that feature high optical density the inventive polymers feature increased dilution of dyes (decrease in optical density) and decrease in the holographic diffraction efficiency.

Abstract: The present invention provides an optical information-recording medium capable of recording and reproducing information with laser beams and having excellent recording characteristics, the optical information-recording medium comprising a support and a recording layer capable of recording information by laser beam exposure, wherein the recording layer contains a dye represented by the following formula (I): wherein R1, R2, R3 and R4 each independently represents a hydrogen atom or a substituent; B1 and B2 represent ?CR5— and —CR6? respectively, or one of B1 and B2 represents a nitrogen atom and the other represents ?CR5— or —CR6?; R5 and R6 each independently represents a hydrogen atom or a substituent; Q1 represents a substituted or unsubstituted arylene group, or a substituted or unsubstituted divalent heterocyclic group; and Q2 represents a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group.

Abstract: An optically readable media (10) has an information-encoding layer (16) and at least one color-forming layer (12) that embodies an optical readout-limiting mechanism. In a first embodiment the at least one color-forming layer contains an additive that does not interfere with the optical readability of the media for a duration of a readout period. The additive, upon exposure to a source of optical radiation that is suitable for reversing the color-forming layer from an optical readout inhibiting state to an optical readout enabling state, undergoes a transformation that maintains the color-forming layer in the optical readout inhibiting state. More specifically, exposure to the source causes the color-forming layer to photobleach and the additive to oxidize, where the oxidation of the additive permanently inhibits the optical readability of the media. The additive may be a leuco dye.

Abstract: Optical recording material which is capable of recording and reading an information signal by utilizing a change in the double refraction caused by a change in the molecular orientation of a side-chain type polymer liquid crystal which has an electrocyclic-reaction-type photochromic compound (or a residue thereof), or a side-chain polymer liquid crystal having in a polymer chain thereof a monomeric unit to which the photochromic compound is bonded.

Abstract: An optical data storage device comprised of periodic nanostructured polymer-based material produced from core-shell particles containing one dye in the core and a second dye in the shell. The combinations of dyes can be UV-Vis-dyes or Vis-NIR or UV-NIR. It is shown that selective single-photon photobleaching of the two dyes leads to increase in density of data storage and allows one to employ single-photon photobleaching to achieve the same storage density as in two-photon-writing.

Abstract: An optical recording material which when exposed to actinic radiation produces a change in optical properties in the exposed regions, thereby providing a pattern of intelligence for storing and retrieving information, the recording material having: a) a polymer containing a covalently bound reactant moiety which is capable of undergoing a chemical transformation upon a one electron oxidation, thus causing the change in optical properties in the exposed regions; and b) a sensitizer capable of absorbing actinic radiation to cause an initial one electron oxidation of the reactant.

Abstract: An optical recording medium includes a substrate having successively disposed thereon a light-reflecting layer, a recording layer and a cover layer, with recording and playback being effected by irradiating the medium with a laser beam having a wavelength of 450 nm or less from the side disposed with the cover layer, wherein a sputter layer having a thickness of 1 to 80 nm is formed between the recording layer and the cover layer, and the sputter layer and the cover layer are adhered with an adhesive. The sputter layer preferably has a thickness within a range from 2 to 50 nm and is preferably formed from a simple substance of Si, Zn, Ag, Al, Ti, Sn or Ge, a compound comprising at least one of the simple substances, or a combination thereof.

Abstract: An optical recording medium includes a substrate and at least a recording layer deposited on or above the substrate, and the recording layer contains at least one formazan-metal chelate compound containing a formazan compound and a metal component; at least one squarylium-metal chelate compound containing a squarylium compound and a metal component; and at least one diarylamine compound.

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: The invention relates to a write-once optical data carrier in which organic and/or inorganic light-absorbing compounds are used as the information layer, especially for high-density optical data carriers which function with a blue laser in the wavelength range of 360-460 nm. The invention also relates to the application of the above-mentioned light-absorbing compound to a suitable substrate (especially polycarbonate), e.g., by spin coating.

Abstract: The present invention provides an optical information recording medium including a substrate having a groove that has a track pitch of 200 to 400 nm and a depth of 20 to 150 nm, the substrate having successively disposed thereon a light-reflective layer, a recording layer on which information is recordable by a laser beam having a wavelength of 450 nm or less, an adhesive layer containing an adhesive, and a cover layer having a thickness of 0.01 to 0.5 mm, wherein a surface of the light-reflective layer at a side thereof at which the recording layer is disposed has a ten-point average roughness Rz of 70 nm or less, a central surface average roughness SRa of 30 nm or less, and an average projection diameter Dv, at a height of 15 nm from a reference plane, of 75 nm or less.

Abstract: Disclosed is an optical recording medium comprising a recording layer. The recording layer contains: a charge generation material generating an electron and a hole by light irradiation; a charge transport material transporting one of the electron and the hole; a charge trap which traps the transported one of the electron and the hole to separate the electron and the hole; and a non-linear optical material which changes optical properties of the recording layer in accordance with electric field formed by the electron and the hole being separated from each other. The non-linear optical material has an asymmetrical carbon atom and a cyclic group. Or, it is a cyclic-group-containing constituent having: an inversion symmetric pi-electron system; at least one of an electron donating group and an electron accepting group which are bonded to the inversion symmetric ?-electron system; and an asymmetrical carbon atom.

Abstract: A silver-based alloy thin film is provided for the highly reflective or the semi-reflective layer of optical discs. Alloy additions to silver include gold, rhodium, ruthenium, osmium, platinum, palladium, copper, silicon, cadmium, tin, lithium, nickel, cobalt, manganese, indium, chromium, antimony, gallium, boron, molybdenum, zirconium, beryllium, titanium, aluminum, germanium and zinc. These alloys have moderate to high reflectivity and reasonable corrosion resistance in ambient environments.

Abstract: The invention relates to an optical data carrier having a preferably transparent substrate that has optionally previously been coated with one or more reflection layers and to the surface of which has been applied a light-writeable information layer, optionally one or more reflection layers, and optionally a protective layer or a further substrate or a covering layer, such that the optical data carrier can be written on or read by means of blue light (preferably laser light having a specified wavelength) or by means of infrared light (preferably laser light having a specified wavelength), wherein the information layer contains (i) light-absorbent phthalocyanine dyes of the formula (I) where Me is a doubly axially substituted Si, Ge, and Sn atom, Pc is an unsubstituted phthalocyanine, and X1 and X2 are each independently halogen, and (ii) optionally, a binder.

Abstract: An optical disc of an embodiment of the invention is disclosed that includes an optically writable label side on which marks are optically writable. The optical disc includes a plurality of tracks on the optically writable label side. Each track has written thereto a repeating pseudorandom series of marks.

Abstract: An optical information recording medium including a substrate, a recording layer, and a cover layer in this order; wherein information is recorded or reproduced by irradiating a laser beam having an wavelength in the range of 380 to 500 nm on the recording layer through a lens having a numerical aperture NA of 0.7 or more; the recording layer includes an organic substance; and the extinction coefficient k of the recording layer is at least 0.1 and less than 0.3.

Abstract: A stamper reception layer 11 of an optical disk producing sheet 1 is composed of a polymeric material that has energy-curing properties and possesses a pre-curing storage elastic modulus of 103 to 106 Pa. The number of deposits on a stamper can thus be reduced with this optical disk producing sheet 1.

Abstract: An information recording medium showing a high light-resistance has a recording layer containing a dye compound having the following formula (I-1) or (I-2): in which each of A1, A2, B1 and B2 is a substituent; each of Y1 and Z1 is a group of atoms required for forming a carbon ring or a heterocyclic ring; each of E and G is a group of atoms required for forming a conjugated double bond chain; X1 is ?O, ?NR or ?C(CN)2, wherein R is a substituent; X2 is —O, —NR or —C(CN)2, wherein R is a substituent; each of L1, L2, L3, L4 and L5 is a methine group which may have a substituent; Mk+ is an onium ion containing a positively charged onium atom to which no hydrogen atom is attached; each of m and n is 0, 1 or 2; each of x and y is 0 or 1; and x is an integer of 1 to 10.

Abstract: The invention relates to an optical recording medium, comprising a substrate and a recording layer, wherein the recording layer comprises a compound of formula (I), wherein R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12 and R13 are each independently of the others hydrogen, G1 or C1-C24alkyl, C2-C24alkenyl, C2-C24alkynyl, C3-C24cycloalkyl, C3-C24cycloalkenyl, C7-C24aralkyl, C6-C24aryl, C4-C12heteroaryl or C1-C12heterocycloalkyl, each unsubstituted or substituted by one or more identical or different substituents G1, wherein R1 and R2, R1 and R13, R2 and R3, R3 and R4, R4 and R5, R5 and R6, R6 and R7, R7 and R8, R8 and R9, R9 and R10, R10 and R11, R11 and R12 and/or R12 and R13 can independently of one another be bonded to one another in pairs separately or, when they contain substitutable sites, via a direct bond or via a —CH2—, —O—, —S—, —NH— or —NC1-C24alkyl-bridge in such a manner that, together with the atoms and bonds indicated in formula (I), five- or six-membered, saturated, unsaturated or aromatic,

Abstract: The invention provides an optically active polyesteramide comprising at least a structural unit represented by the following general formula (I) and a structural unit represented by the following general formula (II). In the general formula (I), R1 and R8 independently represent a hydrogen atom, an alkyl group, or an aryl group. R2 to R5 and R9 to R12 independently represent a hydrogen atom, a halogen atom, an alkyl group, or an alkoxy group. R1 and R2 as well as R8 and R9 may form a 5- or 6-membered ring. R6 and R7 as well as R13 and R14 independently represent a hydrogen atom or an alkyl group. Ar1 and Ar2 independently represent a single bond, 1,4-phenylene, naphthalene-2,6-diyl, or 1,4-phenylene or naphthalene-2,6-diyl substituted by at least one halogen atom, alkyl group or alkoxy group. In the general formula (II), A represents a divalent substituent.

Abstract: An optical disk includes a substrate, a reflection layer, an organic dye layer, a protection layer and a cover layer. When recording information on the optical disk by a laser beam, an organic dye expands due to heat generation caused by laser beam radiation. The laser beam passes through the cover layer of the optical disk during recordation. The information is recorded in grooves formed in the substrate. Hardness of a resin substrate side of the optical disk is higher than that of a cover layer side of the optical disk so as to propagate stresses generated by the thermal expansion of the organic dye toward the cover layer. The hardness relationship between the cover layer side and the substrate side should be established at least when the information is recorded on the optical disk. The optical disk can record the information more finely because deformations of the reflection layer are prevented when recording the information.

Abstract: A phase modulation type optical recording medium has at least one layer of recording film 4 and at least one layer of metal film 3 on a substrate 1 having recessed portions formed therein, wherein one or more layers constituting the recording film include organic material that decomposes upon absorption of laser light to change its refractive index, and width of the recessed portions 2 is set to 0.10 ?m˜0.21 ?m, thereby providing an optical recording medium of write once type with high recording density capable of high reproduction output.

Abstract: An optical recording medium is provided on a substrate with a recording layer. The recording layer comprises at least one kind of the trimethine-cyanine dyes and an additive, wherein the additive has a larger absorbability at the wavelength of laser beam.

Abstract: A CD-ROM type optical disk, whether single-layer or multi-layer, is formed on a substrate having pits in its surface. The pits are filled with a fluorescent composition. Multiple disks such as that one can be glued on top of one another. Suitable fluorescent compositions include xanthene dyes of the eosine group, xanthene dyes of the rhodamine group, acridine dyes, oxazine dyes, azine dyes, indigoide dyes, perylene dyes, violanthrone dyes, cyanine dyes, phthalocynanine dyes, and porphyrins.

Abstract: An optical information recording medium is here disclosed which comprises a transparent substrate, a recording layer comprising an organic dyestuff on which information can be written by a laser beam, a reflective layer and a protective layer formed in this order on the substrate, the aforesaid optical information recording medium being characterized by containing a pit-edge control agent for the formation of recording pits, particularly a dyestuff thermal decomposition accelerator in the recording layer. By the addition of the pit-edge control agent, deviation properties and jitter properties can be remarkably improved, whereby a CD-R medium having a low error rate and good recording properties can be provided. In consequence, stable compatibility with a commercial CD player can be secured.