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: 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 optical information recording medium includes a substrate having disposed thereon a recording layer that is recordable by irradiating the recording layer with a laser having a wavelength of 450 nm or less. The recording layer contains a specific phthalocyanine derivative. An optical information recording method uses the medium.

Abstract: Methods in accordance with the present invention can be applied, in an embodiment, to a media comprising a phase change material to alter a resolved portion of the phase change material to have a resistance different from a resistance of the bulk material. A tip having a substantially larger radius of curvature than the resolved portion can be employed by applying such methods. A substantially anisotropic columnar material can focus a current applied between the tip and the media so that the portion is narrower in width than the radius of curvature. Such highly resolved portions form bits in the media. Other objects, aspects and advantages of the invention can be obtained from reviewing the figures, specification and claims. This description is not intended to be a complete description of, or limit the scope of, the invention.

Abstract: An optical disk is provided with a disk substrate having a recording layer formed on one surface of a substrate and a cover sheet applied over the recording layer; and a display sheet which is affixed to a surface of the disk substrate opposite to a surface covered with the cover sheet and which has substantially the same physical characteristic as that of the cover sheet. The display sheet and the cover sheet are substantially brought into coincidence with each other in terms a direction of heat contraction and a heat contraction rate.

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: A digital data storage medium comprises data in the form of particles which are spectrally coded. The particles generally have the same size and shape. The particles are spectrally coded by tailoring metal species to have specific absorption signature. The size, shape and metal species are selected to increase storage density.

Abstract: A copy-protected optical medium comprising transient optical state change security materials that demonstrating an optical state change when exposed to the wavelengths of from about 770 nm to about 830 nm.

Abstract: An optical information recording medium which makes it possible to reduce the noise level, 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 the main component. The second sub-recording film is formed of a second material containing Al as the main component and having Au 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 side.

Abstract: An optical disk consists of a first laminated layer structure and a second laminated layer structure. The first structure has a first transparent substrate having a first surface and a second surface on both sides thereof, provided on the first surface being a light-incident plane via which a light beam is to be incident in recording or reproduction, formed alternately on the second surface being a plurality of first lands and first grooves, and a first organic-dye recording layer formed on the second surface to cover the first lands and grooves. The second structure has a second substrate, alternately formed on which are a plurality of second lands and second grooves, a reflective film formed on the second transparent substrate to cover the second lands and grooves, and a second organic-dye recording layer formed on the reflective film to face the second transparent substrate.

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: 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 Au added thereto, and disposed in the vicinity of the first recording film.

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 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 Zn as the main component and having Cu 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 side.

Abstract: A storage media can comprise: a plastic substrate, an optical layer, a reflective layer disposed between the optical layer and the substrate, and an adhesive layer disposed between the optical layer and the reflective layer. The optical layer can have an optical layer composition different from the substrate composition. The storage media has a radial deviation over time of less than or equal to 1.15 degrees at a radius of 55 mm, when exposed to a cycle at 25° C. of 50% relative humidity—90% relative humidity—50% relative humidity.

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: A method and apparatus for retrieving information from a three dimensional storage medium uses a three dimensional storage medium having an active medium capable of exhibiting first and second states, a data unit being represented by the ratio between the concentration of the first and second states in a given volume portion of the medium and a data sequence is represented by a sequence of data units. The active medium is irradiated with light as to concentrate light flux through a volume portion of the storage medium so as to generate in the volume portion a detectable non-linear optical response characteristic of the concentration ratio, which is detected and used for tracking.

Abstract: An optical recording medium which comprises a substrate and a recording layer disposed on the substrate, in which the recording layer comprises Ga and Sb, a content of the Sb is 80 atm % to 95 atm % relative to a total content of the Ga and the Sb in the recording layer, and recording and erasing are carried out by a reversible phase change between an amorphous phase and a crystalline phase in the recording layer.

Abstract: An optical information recording medium containing a first information substrate including a first substrate having a guide groove thereon, a first recording layer including a dye, overlying the first substrate and a first reflective layer being a semi-transmittance layer, overlying the first recording layer, a second information substrate comprising, a second substrate having a guide groove thereon, a second recording layer comprising a dye, overlying the second substrate, a second reflective layer being a semi-transmittance layer, located overlying the second recording layer and a light transmittance protective layer overlying the second reflective layer and a transparent intermediate layer. Further, the following relationships (1) and (2) are satisfied: (1) 0.3?nd/??0.7, wherein n represents refractive index in the complex refractive index n-ik of the light transmittance protective layer, d represents a thickness thereof, and ? is at least one of a recording wavelength and a playback wavelength, (2) k?0.

Abstract: An optical information-recording medium which contains a dye having at least two chromophores bonded to each other without any conjugated bond intervening between those chromophores.

Abstract: An optical recording medium which comprises a print-receiving layer as the outermost layer on the side opposite to the light incidence side, wherein a pattern is formed on the print-receiving layer.

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: An increase in cost is minimized while realizing larger capacity. An optical disc 102 includes, from the bottom of the drawing: a substrate 104; a first information recording layer 108 formed on the substrate 104; and a first light transmission layer 110 having a thickness of about 20 ?m formed on the first information recording layer 108. A second information recording layer 114 is formed on the first light transmission layer 110, and a second light transmission layer 116 having a thickness of about 90 ?m is formed on the second information recording layer 114. A laser beam La is irradiated from the side of the second light transmission layer 116 to allow recording and/or reading of an information signal on/from the first and second information recording layers 108 and 114.

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 information layer for an optical information storage medium is formed in a centrifuge. A photopolymerizable composition is applied to a solid base having a relief pattern, and a flexible, transparent film layer is applied on top of the composition. The three are spun in a centrifuge to cause a thin, even distribution of the photopolymerizable composition, which is photopolymerized. The resulting replica is separated from the relief pattern and has a fluorescent material applied thereto. Alternatively, the replica has a non-fluorescent material applied thereto, and the non-fluorescent material is made fluorescent through diffusion. Multiple information layers thus formed can be glued together to form a multilayer optical information storage medium.

Abstract: A limited play optical storage medium for data is described which comprises a first substrate, a reflective layer, a data layer disposed between said substrate and said reflective layer; a reactive layer comprising at least one carrier, and at least one reactive material, and an optically transparent second substrate comprised of a polymethacrylate copolymer or blend comprising a polymethacrylate copolymer or homopolymer. The second substrate is disposed between the reactive layer and a laser incident surface and is tailored to provide an oxygen permeability in a range between about 0.1 Barrers and about 1.35 Barrers at 25° C.

Abstract: The present invention provides a formulation for a reactive dye layer for a limited-play optical storage medium, the reactive formulation including at least one carrier material or curable acrylate monomer, at least one reactive material disposed within the carrier material or acrylate monomer, and at least one photo-bleaching retarder material disposed within the at least one adhesive material. The at least one photo-bleaching retarder material includes at least one polymeric polyhydroxy compound selected from the group consisting of polyhydroxystyrenes, cellulose, and functionalized cellulose derivatives.

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: An optical data storage medium (20) for recording by means of a focused radiation beam (29) is described. The radiation beam having a wavelength ? enters through an entrance face (28) of the medium during recording. The medium has a substrate (21) with a surface (24) including a guide groove with a depth g. An inverted stack of layers is present on the substrate (21) including a reflective layer (24a) with a complex refractive index ñM?=nM??i*kM?, in substantial conformity with the surface (24) of the substrate, a transparent layer (22) through which the radiation beam (29) is incident with a complex refractive index ñT?=nT??i*kT? and a recording layer (25) of a material having a complex refractive index ñR?=nR??i*kR? and having a thickness dRG in the groove portion and a thickness dRL in the portion between grooves. The recording layer is interposed between the reflective layer (24a) and the transparent layer (22). When 0.25/(3.0+kM?2)+0.17<g*nT/?<0.22/(3.0+kM?2)+0.45 and 0.2<(dRG?dRL)/g<0.

Abstract: A method of manufacturing an optical storage medium is provided, which comprises at least a transparent spacer layer (22) or transparent cover layer. This layer is provided by spincoating a liquid layer (22) between an inner radius ri and outer radius ro and substantial solidification by means of exposure to e.g. UV-radiation. The solidification of the liquid (22) is started at ri at a moment in time defined as t=ti. The solidification of the liquid (22) at ro takes place at a moment in time defined as t=to and to=ti+d and d>1 s. The solidification of the liquid (22) between ri and ro takes place at a moment in time between ti and to. The advantage is that the radial thickness uniformity of the solidified liquid (22) is substantially improved and better than +/??m.

Abstract: A multi-stack optical data storage medium (20) for rewritable recording using a focused radiation beam (30), entering through an entrance face (25) is described. The medium (20) has a substrate (1a, 1b) and an L0 recording stack (2) and an L1 recording stack (3) both comprising a phase-change type L0 and L1 recording layer and the recording stacks are separated by a transparent spacer layer (4). The L0 recording stack (2) is present at a position closest to the entrance face (25) and has an optical transmission of TL0a and TL0c when the phase-change layer respectively is in the amorphous phase and in the crystalline phase. The medium (20) contains pre-recorded information modulated in at least one of: an embossed pregroove (21) in the substrate (1a, 1b), embossed pits in the substrate and recorded phase-change marks in at least one of the recording layers L0 and L1 (6, 11).

Abstract: The invention relates to a data recording device comprising microtips and a recording medium. The recording medium comprises a substrate with a preferably-carbon resistive layer disposed thereon, said resistive layer being covered with an active layer. According to the invention, the aforementioned active layer can pass from a first electrical resistivity value to a second electrical resistivity value when a voltage is applied between the microtips and a counter electrode. The inventive data recording device also comprises at least one carbon resistive element which is disposed between the active layer and the microtips.

Abstract: In a method of entering information into an optically writable and readable data storage medium having a polymer film which can be changed locally by heating in order to store information and to which there is assigned an absorber dye (34) which is set up to absorb a write beam (36), at least partly, and to transfer the heat produced in the process, at least partly, locally to the polymer film, first of all the absorber dye is heated locally in a predetermined region of the polymer film in accordance with the information to be entered, specifically by means of a pulsed write beam (36). After that, the absorption properties of the absorber dye (34) are changed by means of light, to be specific preferably by means of a fixing beam (37) which bleaches (38) the absorber dye (34) in the written region of the polymer film.

Abstract: The present invention provides a method of manufacturing an optical recording medium having two recording layers on a supporting substrate and an optical recording medium obtained according to the method.

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: A method of manufacturing an optical recording substrate, comprising the steps of: contacting the surface having pit or land/grooves of a stamper having the pit or land/grooves to an organic polymer sheet having a glass transition temperature of 120 to 190° C., a single-pass birefringence retardation of +10 nm to ?10 nm and a thickness of 0.35 mm or less under reduced pressure; and thermally pressing them. According to this method, an optical recording substrate which can transfer a stamper pattern to a thin organic polymer sheet easily and thoroughly can be manufactured.

Abstract: An optical recording medium, with a construction and a manufacturing method thereof corresponding to those of a read-only optical recording medium and which can be manufactured inexpensively, which enables additional recording of the above-described codes, marks, and other new information, which can be recorded reliably and has satisfactory characteristics, is provided. A construction is adopted in which the optical recording medium S has an information layer 2 including a portion in which information is recorded by physical shape changes in, at least, the thickness direction or the track width direction, and which comprises a reflective film 3; the reflective film is formed of Al alloy or Cu alloy with an electrical resistivity of 20 ??·cm or more and 90 ??·cm or less, and information can be additionally recorded on the reflective film 3 by thermal recording.

Abstract: A first dielectric layer 3, a multilayer magnetic film 10 in which a first magnetic layer 4 having perpendicular magnetic anisotropy at room temperature, a second magnetic layer 5 having inplane magnetic anisotropy at room temperature, and a third magnetic layer 6 having perpendicular magnetic anisotropy at room temperature are sequentially laminated, a second dielectric layer 7, a reflective layer 8, and a protective layer 9 are sequentially laminated onto one principal plane of a disk substrate 2 on which a land and a groove exist, thereby forming a magnetooptic disk 1. Saturation magnetization of the second magnetic layer 5 is set to a range from 8.80×10?2 to 1.76×10?1 Wb/m2. A gas pressure upon film creation of the second magnetic layer is set to a range from 0.6 to 3.0 Pa. A content ratio of Co in the third magnetic layer 6 is set to a range from 15 to 17 atom %.

Abstract: An optical information recording medium which makes it possible to reduce the noise level, 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 the main component. The second sub-recording film is formed of a second material containing Al as the main component and having Ti 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 side.

Abstract: It is an object of the present invention to provide a multilevel optical recording medium in which influence of variation in characteristics of a recording layer in a plane of the recording layer on reproduced data can be corrected The multilevel optical recording medium according to the present invention includes at least a recording layer 12 and is constituted so that data can be recorded therein in a multilevel manner by controlling a state of the recording layer 12 among multiple stages and the multilevel optical recording medium according to the present invention is characterized in that a plurality of calibration signals are stored in the recording layer 12.

Abstract: The present invention provides a magneto-optical recording medium including a recording layer, an intermediate layer and a reproducing layer stacked in this order. Information recorded in the recording layer is transferred to the reproducing layer through the intermediate layer so that the information is reproduced. The reproducing layer includes an upper reproducing layer, a coupling layer, and a lower reproducing layer formed in this order on the intermediate layer. Magnetic information in the upper reproducing layer in an area whose temperature is increased to a predetermined temperature is transferred to the lower reproducing layer through the coupling layer.

Abstract: An optical recording/reproducing method and an optical recording medium capable of performing excellent optical recording with a simple structure in a recording layer made of environmentally friendly materials. The optical recording medium has a recording layer on a substrate. The recording layer has a pair of dielectric layers of which states are altered by a laser beam that is an energy beam of which intensity is modulated according to information to be recorded. This recording layer also has a assisting material layer sandwiched by these dielectric layers. The assisting material layer includes an element selected from Sn, Ti, Si, Bi, Ge, and C as a principle component, while the dielectric material as a base material for the dielectric layers is any one of ZnS, SiO2, AlN, and Ta2O5.

Abstract: In one aspect the present invention provides a storage medium for data, the storage medium comprising: a) a substrate, a physical portion of which comprises at least one polyimide, and b) at least one data layer on the substrate. The substrate comprising a polyimide exhibits low axial displacement and beneficial damping characteristics.

Abstract: An optical recording/reproducing method and an optical recording medium capable of performing excellent optical recording with a simple structure in a recording layer made of environmentally friendly materials. The optical recording medium has a recording layer formed on a substrate and made of a mixture of a recording assist material and a dielectric material. A laser beam of which intensity is modulated in accordance with information to be recorded is irradiated onto this recording layer to cause a state change in the recording assist material and/or the dielectric material. The information can be recorded by changing optical characteristics thereof such as reflectivity. The recording assist material includes an element selected from Sn, Ti, Si, Bi, Ge, and C as a principle component, while the dielectric material as a base material for the dielectric layers is at least one of ZnS, SiO2, AlN, and Ta2O5.

Abstract: An optical recording medium which comprises a print-receiving layer as the outermost layer on the side opposite to the light incidence side, wherein a pattern is formed on the print-receiving layer.

Abstract: The present invention provides an optical information recording medium that includes a substrate including a groove with a track pitch of 200 to 400 nm and a groove depth of 20 to 150 nm and having successively disposed thereon a light reflecting layer, a recording layer containing a dye in which information is recorded by irradiation with a laser beam having a wavelength of no greater than 450 nm, an adhesive layer, and a cover layer with a thickness of 0.01 to 0.5 mm. A surface of the optical information recording medium on a side disposed with the cover layer has a center surface average roughness (SRa1) of no greater than 3.0 nm when measured over a large surface area and a center surface average roughness (SRa2) of no greater than 3.0 nm when measured over a minute surface area.

Abstract: An optical information recording medium of this invention includes a substrate, a light incident surface, a first reflecting layer formed between the substrate and the light incident surface, a second reflecting layer formed between the first reflecting layer and the light incident surface and stacked on the first reflecting layer, the second reflecting layer being made of the same material as that of the first reflecting layer, and a phase change optical recording layer formed between the second reflecting layer and the light incident surface, the phase change optical recording layer transiting between a crystal state and an amorphous state when irradiated with a light beam.

Abstract: A fluorescent composition for use with single-layer and multilayer optical discs for CD ROM, DVD and WORM type devices with fluorescent reading is disclosed. The composition comprises a fluorescent dye, film-forming polymer, plasticizer, surfactant and light stabilizer. A method of increasing fluorescent signal level from the optical discs both for single-layer and multilayer optical memory materials is also disclosed along with the resulting optical discs.

Abstract: An optical information recording medium containing a first information substrate including a first substrate having a guide groove thereon, a first recording layer including a dye, overlying the first substrate and a first reflective layer being a semi-transmittance layer, overlying the first recording layer, a second information substrate comprising, a second substrate having a guide groove thereon, a second recording layer comprising a dye, overlying the second substrate, a second reflective layer being a semi-transmittance layer, located overlying the second recording layer and a light transmittance protective layer overlying the second reflective layer and a transparent intermediate layer. Further, the following relationships (1) and (2) are satisfied: (1) 0.3?nd/??0.7, wherein n represents refractive index in the complex refractive index n-ik of the light transmittance protective layer, d represents a thickness thereof, and ? is at least one of a recording wavelength and a playback wavelength, (2) k?0.

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: High sensitive organic dye-in-polymer (DIP) medium for write-once-read-many (WORM) optical discs with fluorescent reading. The medium consists of a fluorescent color means, capable of absorbing writing radiation produced by a laser, a compound capable of generating free radicals upon influence of heat produced by the writing radiation and a polymer capable of producing a translucent film enabling high quantum yield of the fluorescence induced in the color means. The color means can be selected from xanthene dyes of the eosine and rhodamine groups, acridine, oxazine, azine, peylene, violanthrone, cyanine, phtalocyanine, indigoide colors and porphyries. The free radicals generating compound can be chosen from the group of compounds comprising azo and diazoi compounds or peroxyde compounds. The film producing polymer can be selected from the group of compounds comprising cellulose ethers, vinyl resins or acrylic resins.