Abstract: Recording and reproducing characteristics and data saving reliability are secured in a write-once two-layer recording medium. A second recording layer from a side irradiated with light for recording and reproduction includes organic dye shown by a general formula of a chemical formula 3 described below (in the formula, R1 and R2 are alkyl groups of carbon number 1 to 4; Y1, Y2 respectively are organic groups independently; and X is Cl04, BF4, PF6, SbF6), and organic dye shown by a general formula of a chemical formula 4 described below (in the formula, R1, R4 are alkyl groups of carbon number 1 to 4; R2, R3 are alkyl groups of carbon number 1 to 4 or groups forming 3 to 6 membered rings by being coupled; Y1, Y2 respectively are organic groups independently; and X is Cl04, BF4, PF6, SbF6), to secure durability.

Abstract: An optical article comprising a mark disposed on the optical article; wherein the mark comprises an optical state change material; wherein the optical state change material undergoes a change in its optical state when exposed to an activation signal selected from one or more of a laser, thermal energy, infrared rays, X-rays, gamma rays, microwaves, visible light, ultraviolet light, ultrasound waves, radio frequency waves, electrical energy, chemical energy, magnetic energy, and mechanical energy; wherein the optical article is transformed from a pre-activated state to an activated state when an authorized activation method is used; and wherein the optical article is transformed from a pre-activated state to an incorrectly activated state when an unauthorized activation method is used. A method and a system for changing the functionality of the optical article are also provided.

Abstract: A cyanine compound is represented by: wherein, R11 and R12 each independently represent a hydrogen atom, a hydroxyl group, a halogen atom, a nitro group, a cyano group, an organic group having 1 to 30 carbon atoms, or a group represented by the following general formula (II), (II?), or (III); R13 and R14 each independently represent a hydrogen atom, an organic group having 1 to 30 carbon atoms, or a substituent represented by the following general formula (III); R11 and R12 may be connected together to form a ring structure; R19 represents a hydrogen atom or an organic group having 1 to 30 carbon atoms; R13 and R14 may be connected together to form a heterocycle; N—R13 may be connected together with a methylene group in a polymethine chain to form a heterocycle; Z00 is an organic group having 1 to 10 carbon atoms; m is 0 or 1; s is 2 to 8; Anq? represents an anion having a valence of q; q is 1 or 2; and p represents a coefficient for maintaining charge neutrality.

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: The present invention discloses an apparatus for indicating the passage of time, comprising a substrate and an indicating layer formed on the substrate. The indicating layer comprises a polymer matrix and a predetermined amount of redox compound under the reduced form. The redox compound is dispersed in the polymer matrix and has the following properties: the reduced form of the redox compound reacts with oxygen to form the oxidized form of the redox compound; the hue or color density of the reduced form of the redox compound is different from that of the oxidized form of the redox compound; and the hue or color density of the indicating layer varies as the time for the reduced form of the redox compound contacting with oxygen in environment increases to have the amount of the oxidized form of the redox compound increase so as to indicate the passage of time.

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: An optical recording medium having excellent light resistance that includes a substrate; and a recording layer which is provided on the substrate directly or on another layer provided on the substrate, wherein the recording layer is capable of recording and/or reading information by irradiating light thereon, the recording layer includes a metal complex compound with an azo compound having a coupler component with indandione and a diazo component with a nitrogen-containing heterocyclic aromatic ring structure, and a nickel or cobalt ion coordinated to the azo compound.

Abstract: Provided is an optical recording medium including, in sequence: a first substrate; a first information recording layer; an intermediate layer; a second information recording layer; and a second substrate having wobble convex portions on its surface, wherein information is recorded on or reproduced from the first information recording layer and second information recording layer by irradiation with a laser beam from a first information recording layer side, wherein the second information recording layer includes, over the second substrate, a light reflective layer, a dye recording layer, and an inorganic protective layer, wherein the inorganic protective layer has a thickness of 3 nm to 40 nm, and wherein the dye recording layer includes a cyanine compound expressed by General Formula (I) and a squarylium compound expressed by General Formula (II):

Abstract: A system for altering a functionality of an optical article from a pre-activated state to an activated state, comprising an optical article comprising an optical data layer for storing data, an external radiation source for generating an external stimulus adapted to interact with the optical article, such interaction causing a change in optical accessibility of optically stored data, a directing material, wherein said directing material is for directing the external stimulus to selective portions of the optical article, thereby altering the functionality of the optical article from a pre-activated state to an activated state; a convertible element capable of responding to the external stimulus to irreversibly alter the optical article from the pre-activated state of functionality to the activated state of functionality, wherein said convertible element comprises a color-shift dye, a magnetic material, a thermo-chromic material, a magneto-optical material, a light scattering material, a phase-change material,

Abstract: The invention provides dyes for optical disc recoding media, having the general formula: wherein m, n is independently selected from integers 0-3; X represents oxygen, sulfur, C—R1, or N—R2R3; Y is oxygen or sulfur; each of R1, R2, and R3 can be the same or different; and Z? is a cation. The dyes have a maximum absorption in wavelength of 300-500 nm and can be used in recording layers of high density optical disc recording media.

Abstract: Provided is an optical information recording medium employing an In-Groove recording system, and having a preferable recording characteristic with a high modulation degree and low jitter characteristics. The medium is comprised of a circular-disk shaped substrate 2 having a through hole at a center portion thereof and a spiral guide groove 3 on one surface thereof; a reflective layer 4 formed on the guide groove 3 of the substrate 2; a recording layer 5 formed on the reflective layer 4 and composed of an organic material including a dye; a protection layer 6 provided on the recording layer 5; and a light-transmissive layer 6 formed on the protection layer 6. The recording layer 5 includes an organic dye which is an azo metal complex compound having a structure represented by (Chemical formula 1) and a functional group represented by (Chemical formula 2).

Abstract: Disclosed is to provide with an optical recording medium of a write-once type in which an excellent recording characteristic can be obtained over low speed recording to high speed recording.

Abstract: An optical information recording medium has a substrate, and an optical reflection layer, an optical recording layer containing an organic dye, an interlayer, and a cover layer formed in this order on the substrate. The interlayer contains a sputtered Nb2O5—Al2O3-based composite oxide having an Nb2O5 content of more than 50 mol % and less than 60 mol %.

Abstract: The present invention is directed to a film forming, photoactive, homogeneously mixed material comprising a complex prepared from (a) at least one ionic photosensitive compound which may undergo a photoreaction, selected from photoisomerizations, photocycloadditions and photoinduced rearrangements, and/or (a?) at least one photosensitive polyelectrolyte (“second polyelectrolyte”) carrying residues which may undergo said photoreaction, and (b) at least one (“first”) polyelectrolyte carrying charges which are opposite to those of the active groups of the photosensitive material. This material has unique photochemical properties in that non-scattering, optically clear films may prepared therefrom which allow light-induced generation of optical anisotropy and of topological surface structures, e.g. such as surface relief gratings (SRG).

Abstract: An optical information recording medium, which is made of a resin provided with photoreactivity containing organometal compound, has a recording layer on which, after a photoreaction are brought about when predetermined initialization light is irradiated to the medium and then the resin is hardened, at a time of recording information, a recording mark is formed when predetermined recording light is condensed to the medium, and a temperature of the medium near a focal point of the recording light is increased and the organometal compound is transubstantiated, and at a time of reproducing information, the information is reproduced based on returned light according to predetermined reading light being irradiated.

Abstract: An aspect of the present invention relates to an optical information recording medium comprising a recording layer, wherein the recording layer comprises a cationic dye and a polynuclear azo metal complex dye comprising an azo dye and a metal ion, and a method of recording information comprising recording information on the recording layer comprised in the optical recording medium, and conducting the recording by irradiation of a laser beam having a wavelength of equal to or shorter than 440 nm onto the optical information recording medium. Another aspect of the present invention relates to a photo sensitizer.

Abstract: The azo-metal chelate dye to which the present invention is applied is a compound formed as follows: for example, 1,3,4-thiadiazole ring is selected as the diazo component; the diazo component is combined with a coupler component having condensed rings including a fluorine-substituted alkylsulfonylamino group and an amino group, to form an azo dye compound; and the azo dye compound forms chelate bonds with at least one metal selected from the group consisting of Co, Ni, Cu and Pd. Here, two absorption bands (OD1 and OD2) are seen in the absorption spectrum, which is measured in a range of 400 to 800 nm wavelengths. The azo-metal chelate dye is characterized in that the optical density ratio (OD2/OD1) of the two absorption bands is greater than 1.25. By using this azo-metal chelate dye, an optical recording medium capable of high-speed recording is provided.

Abstract: An aspect of the present invention relates to an optical information recording medium comprising a recording layer on a surface of a support, wherein 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 being a complex of six azo dyes and seven transition metal ions. A further aspect of the present invention relates to a method of recording information onto the optical information recording medium and a novel azo metal complex dye.

Abstract: The present invention is aimed to provide a high-performance single-sided double-layer optical recording medium with reduced crosstalk between recording marks, wherein favorable recording signal properties are obtained even from the second recording layer located more distant from the substrate to which the light is applied, and reproducing method thereof, and an optical recording and reproducing apparatus. The optical recording medium possesses the following aspects: the optical recording medium comprises a first substrate, a first information layer, an intermediate layer, a second information layer and a second substrate in this order; the first information layer comprises a first recording layer; the second information layer comprises a second reflective layer, a second recording layer with an organic dye and a protective layer; and the pyrolysis temperature range, the DTA peak width of the thermal analysis on the organic dye in the second recording layer, is 45° C. or less.

Abstract: An optical data storage system and method with non-destructive multiple readout of 3-D data stored in multiple layers uses two-photon induced fluorescence modulation. The novel system uses the photochromic properties of the open and closed form of diarylethene in the two-photon energy transfer-based read-out method of a 3-D optical data storage system, providing more than 10,000 readout cycles without significantly compromising the stored data. The system of the present invention can be recorded and read out using the same wavelength simply by changing the intensities. Also, since the incident intensity used in two-photon readout is low due to the efficient absorption of the two-photon absorbing fluorene dye, a less expensive, nanosecond laser diode can be used, making this two-photon 3-D data storage system less expensive, stable, highly responsive, and reliable. This photochromic system is capable of either write-once read many (WORM) or erasable and rewritable 3D optical data storage.

Abstract: An optical information recording and reproducing device 1 irradiates initialization light L1 to an optical information recording medium 100 having a recording layer 101 made of photopolymerization-type photopolymer in advance to bring about the photopolymerization or the photocrosslinking to perform the initialization processing, and condenses a recording light beam L2c having a comparatively strong light intensity to a target position in the recording layer 101 and increases the temperature thereof to transubstantiate the target position to record a recording mark RM at the time of recording information, and condenses a reading light beam L2d having a comparatively weak light intensity to the target position and receives a returned light beam L3 having a sufficient light amount reflected by the recording mark RM at the time of reproducing information, which makes it possible to reliably record the recording mark RM and stably read out the recording mark RM.

Abstract: According to one embodiment, a write-once type information storage medium using a recording material which has a low to high characteristic that a light reflectivity in a recording mark increases with respect to a non-recording area and which has a recording characteristic in accordance with a principle of recording without substrate deformation, wherein the recording material includes at least an organic metal complex, and wherein the organic metal complex includes a center metal.

Abstract: A system for recording and/or transmitting optical data or visual images includes an optical data or visual image recording medium and a light and/or heat source. The medium includes a markable coating established on a substrate. The markable coating includes a leuco dye and a developer precursor including a compound that undergoes rearrangement in response to a stimulus, thereby forming a developer that reacts with the leuco dye. The light/heat source is positioned so as to illuminate and/or heat the medium in a predetermined manner to i) cause photochemical and/or photothermal rearrangement of the developer precursor to form the developer which reacts with the leuco dye to form an optically detectable mark, or ii) cause at least one optically detectable mark previously formed on the markable coating to produce at least one readable pattern.

Abstract: Disclosed is an optical information recording medium whose recording method is In-Groove recording, wherein such optical information recording medium offers good recording characteristics associated with high modulation degree and low jitter characteristics. This optical information recording medium includes: a disc-shaped substrate 2 having a through hole at the center and a guide groove 3 formed helically on one side; a reflective layer 4 formed on top of the aforementioned guide grooves 3 on the aforementioned substrate 2; a recording layer 5 formed on top of the aforementioned reflective layer 4 and made of an organic substance containing dye; a protective layer 6 formed on top of the aforementioned recording layer 5; and a light transmissive layer 6 formed on top of the aforementioned protective layer 6. The recording layer 5 contains an organic dye having a structure expressed by (Chemical Formula 1) and a functional group expressed by (Chemical Formula 2).

Abstract: An indole compound represented by general formula (I): wherein R1 and R2 each represent a hydrogen atom, a hydrocarbon group having 1 to 30 carbon atoms or a substituent represented by general formula (II); R3 and R4 each represent an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms or an aryl group having 6 to 30 carbon atoms; R5, R6, R7, and R8 each represent a hydrogen atom, a hydrocarbon group having 1 to 30 carbon atoms, a halogen atom, a hydroxyl group, a nitro group, a cyano group, NHR or NR?R?; R, R?, and R? each represent an alkyl group having 1 to 10 carbon atoms, or R? and R? are taken together to form a ring; R5 and R6, R6 and R7, or R7 and R8 may be taken together to form a ring; Anq? represents a q-valent anion; q represents 1 or 2; and p represents a coefficient necessary to maintain charge neutrality.

Abstract: According to one embodiment, a write-once type information storage medium comprises a recording layer which is formed by mixing a plurality of organic dye based recording materials whose molecular weights are different from each other, and wherein a mixture ratio of organic dye based recording materials whose molecular weight is small is larger than a mixture ratio of organic dye based recording materials whose molecular weight is large.

Abstract: A coating composition for optical recording includes a uniform dispersion of polymer particles in a liquid, a quantity of dye particles uniformly dispersed in the liquid, the dye particles being soluble in the polymer but substantially insoluble in the liquid, and a quantity of radiation absorber material adapted to absorb radiation at a wavelength of a laser for optical recording of an image.

Abstract: A preparation method of a dye incorporated in a recording layer for a high density optical recording medium, having the following general chemical structural formula (I): is provided.

Abstract: To provide an optical information recording medium including a pigment appropriate for high-density and high-speed optical recording by the blue laser light of 350 to 500 nm and especially around 400 nm (for example, 405 nm), enabling recording at low power, suppressing thermal affect of recording to the optical recording layer, and assuring a reflection ratio or modulation degree by the change of a refraction index n and an attenuation coefficient k; and to provide a recording method thereof. Instead of the recording based on the optical phase difference obtained by a change ?n of the refraction index n of the pigment as in the conventional method, a pigment capable of performing recording based on the change ?k of the attenuation coefficient k has been obtained. Recording may be performed mainly by the change ?k of the attenuation coefficient k.

Abstract: An optical information recording medium is provided having a superior jitter property even when an organic substance is used for a recording layer. The optical information recording medium has a substrate having a penetrating hole in a central portion thereof and a spiral pre-groove provided in one surface of the substrate, a reflection layer provided on the surface of the substrate in which the pre-groove is provided, a recording layer which is provided on the reflection layer and which is composed of an organic substance including a dye, and a light transmissive cover layer provided on the recording layer. In the optical information recording medium, the cover layer has an elastic modulus of 40 MPa or less at 25° C. in an interface region facing the recording layer.

Abstract: If an ultraviolet curing resin is colored by contamination by another substance, there have been issues regarding increased cost and the environmental burden of treating the waste solution due to an inability to recycle the resin as it is. The ultraviolet curing resin that is in a colored, uncured state is decolored in the present invention by irradiation of light having a wavelength in the vicinity of the maximum absorption wavelength of the coloring material, and then recycled. As a result, it is possible to reduce costs and contribute to the protection of the environment.

Abstract: A disc having a relief pattern and a transprint method thereof are provided. The transprint method for transprinting the relief pattern on a substrate of the disc includes the following steps. First, a transprint template is provided. A first surface of the transprint template has a complementary pattern corresponding to the relief pattern. Next, a pattern layer is formed on the substrate. Then, the transprint template is placed on and covers the pattern layer until the first surface of the transprint template closely contacts a second surface of the pattern layer, so that the relief pattern is formed on the second surface. Afterward, the pattern layer is cured by irradiation. Later, the transprint template is removed for exposing the second surface with the relief pattern.

Abstract: The optical recording medium according to the present invention comprises a transparent substrate, a recording layer, an optical reflective layer, and a protective layer, wherein the last three layers mentioned are formed on the substrate in this sequence, and enables recoding at a recording linear velocity of 27.9 m/s or more. The optical reflective layer is characterized in that the layer comprises any one of Ag and an alloy mainly made from Ag and a x-ray diffraction spectrum of the optical reflective layer satisfies the relational expression of 0.2<I (200)/I (111)<0.4, in which I (111) is an intensity of the x-ray diffraction peak from (111) plane and I (200) is an intensity of the x-ray diffraction peak from (200) plane determined by x-ray diffraction based on ??2? method when the incidence angle relative to the surface of the optically transparent substrate being ?.

Abstract: To provide a squarylium compound forming a metal complex, expressed by the general formula (I): where R1 and R2 are the same or different and each of R1 and R2 represents a substituted or unsubstituted alkyl, aralkyl, aryl, or heterocyclic group; Q represents a metal atom having coordinating ability; q represents 2 or 3; R3 represents a substituted or unsubstituted aralkyl, or aryl group; R4 represents a substituted or unsubstituted alkyl, aralkyl, or aryl group,’ R5 represents a hydrogen atom, or substituted or unsubstituted alkyl, aralkyl, or aryl group; R6 represents a halogen atom, nitro group, cyano group, or substituted or unsubstituted alkyl, aralkyl, aryl, or alkoxy group; p represents any integer ranging from 0 to 4; and RGs are the same or different and any adjacently located two R6s optionally form a substituted or unsubstituted aromatic ring together with two adjacent carbon atoms when p is 2, 3 or 4.

Abstract: The present invention is to provide an optical recording medium which is capable of performing good recording and reproducing by using a laser having a wavelength of 300 to 900 nm, a novel azo metal chelate compound, and a novel azo compound. Furthermore, the present invention is to provide an optical recording medium having an azo metal chelate compound in a recording layer.

Abstract: To provide an optical recording medium including: a substrate having at least one of grooves and pits on a surface thereof; and a dye recording layer formed over the substrate, wherein the dye recording layer comprises a cyanine dye represented by the following General Formula (I), a squaric acid complex represented by the following General Formula (II), and an amine compound.

Abstract: A recording layer including a novel organic compound for a high density optical recording medium is provided. The information may be recorded on the recording layer at a 2× speed or higher speed with a relatively lower writing power so that heat distribution of the recording layer in the irradiated area is not likely to become steep both in time and space. The organic compound incorporated in the recording layer has the following general chemical structural formula (I).

Abstract: A recording layer including a novel dye for a high density optical recording medium, employing short wavelength laser source with a wavelength not longer than 530 nm for recording high density information and reproduction/playback of the high density information recordings, is provided.

Abstract: Improved structures of optical medium are disclosed. According to one embodiment, multiple reflective layers are used. These reflective layers are in different materials. At least one of the reflective layers allowing a significant amount of a laser beam to transmit is used to protect another reflective layer with superior reflectivity from moisture on one side. An additional reflective layer may also be used to protect the high reflective layer from moisture on the other side.

Abstract: An optical recording medium on which high-density recording and reading of optical information can be conducted by a short-wavelength light such as a blue laser beam is provided. In an optical recording medium comprising at least a substrate and a recording layer thereon that can record or read information by irradiation with light, the recording layer contains an azacyanine dye represented by general formula [I]: wherein R1 and R2 each independently represent a hydrogen atom or an optionally substituted linear or branched alkyl group having one to four carbon atoms; R3 represents a hydrogen atom or a hydrocarbon group; R4 represents a hydrogen atom or a linear or branched alkyl group having one to four carbon atoms; R5 represents an optionally substituted aromatic ring group or an optionally substituted unsaturated heterocyclic group; R4 and R5 may be combined together to form a ring; X? represents a counter anion; and the benzene ring A may be optionally substituted.

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: A recording layer including a novel dye for a high density optical recording medium, employing short wavelength laser source with a wavelength not longer than 530 nm for recording high density information and reproduction/playback of the high density information recordings, is provided.

Abstract: To provide an optical recording medium on which recording/retrieving of high density optical information is possible by a short wavelength light such as a blue laser. An optical recording medium comprising a substrate and a recording layer capable of recording or retrieving information by irradiation with light, formed on the substrate, wherein the recording layer contains the cyanine dye represented by the following formula (I): wherein each of A1 and B1 which are independent of each other, is an aromatic ring which may have a substituent, provided that at least one aromatic ring of A1 and B1 contains a nitrogen atom; each of R1 and R2 which are independent of each other, is a substituent, provided that R1 and/or R2 may be bonded to other cation; each of X1, X2, X3 and X4 which are independent of one another, is an organic group, provided that a pair of X1 and X2, and/or a pair of X3 and X4, may be mutually bonded to form a cyclic structure; Y1 is a hydrogen atom or an organic group; and Z is an anion.

Abstract: The present invention relates to an optical recording medium containing a first substrate, a first information layer, an intermediate layer, a second information layer and a second substrate in this order, wherein the first information layer contains a first recording layer disposed on the first substrate and the second information layer contains a reflective layer, a second recording layer containing an organic dye and a protective layer which are disposed on the second substrate in this order; and the second recording layer contains an organic dye which is at least one elected from the group consisting of the specified squarylium metal chelate compounds.

Abstract: Cyanine compounds represented by the general formula (I) which exhibit decomposition behavior suitable for the optical recording material to be used in optical recording layers of optical recording media for high-speed recording: (I) wherein A and B are each an optionally substituted benzene or naphthalene ring; X is O, S, Se, CR3R4, or NY; at least either of R1 and R2 is a group represented by the general formula (II) or (III) and when only either is a group represented thereby, the other is an organic group having 1 to 30 carbon atoms; R3 and R4 are each an organic group having 1 to 30 carbon atoms; Y is hydrogen or an organic group having 1 to 30 carbon atoms; at least either of Y1 and Y2 is a group represented by the general formula (IV) and when only either is a group represented thereby, the other is hydrogen or an organic group having 1 to 30 carbon atoms; Z is hydrogen, halogeno, or cyano; Anm? is an m-valent anion; m is an integer of 1 or 2; and p is a coefficient capable of keeping the electric char

Abstract: The invention provides an azo metal chelate dye suitable for use in a recording layer of an optical recording medium capable of high-speed recording or an optical recording medium having plural recording layers, and an optical recording medium. The azo metal chelate dye comprises an azo dye compound represented by the general formula (1) and Zn2+: (wherein R1 represents a linear or branched alkyl group that may be substituted, or a cycloalkyl group that may be substituted; Y represents a linear or branched alkyl group substituted with at least two fluorine atoms; R2, R3, R4, R5 and R6 each independently represents a hydrogen atom or a linear or branched alkyl group that may be substituted, and R3 and R4, R4 and R5, or R5 and R6 may be bonded with each other to form a ring; and a proton is released from the compound of formula (1) to form the chelate dye together with Zn2+).

Abstract: A compound represented by the following general formula (I), wherein ring A and ring B each independently represent a benzene, naphthalene, or heterocyclic ring which may be substituted; R1 and R2 each independently represent an alkyl group having 1 to 8 carbon atoms which may be substituted; R1 and R2 may be linked together to form a ring; a methylene group of the alkyl group having 1 to 8 carbon atoms may be replaced by —O— or —CH?CH—; Anq? represents a q-valent anion, where q is 1 or 2; p represents a coefficient to keep the charge neutral.

Abstract: A recording layer including a novel organic dye compound (I) for a high density optical recording medium is provided. The organic dye compound (I) has the following general chemical structural formula: wherein [A]+ includes alkaline metal ion, wherein R1, R2, R3, R4, R5 and R6 each independently represent hydrogen, straight or branched C1-8 alkyl, C1-3 alkoxyl, halogen, nitro, benzyl group or substituted benzyl group wherein a substituent thereof is C1-2 alkyl, C1-2 alkoxyl, halogen or nitro. The organic dye compound (I) exhibits a maximum absorbance at a wavelength range of 400-550 nm.

Abstract: The cyanine compound of the present invention is represented by general formula (I) below and suitable as an optical recording material used in a recording layer of optical recording media on which recording and play-back are conducted with laser beam. The cyanine compound of the present invention particularly exhibits appropriate thermal decomposition behavior to attain sensitivity compatible with high-speed recording.

Abstract: A dye or dyes are selected, which are capable of absorbing a laser beam with a wavelength of 350 to 500 nm and are capable of recording sub-information using a laser beam with a wavelength of 640 to 680 nm or 750 to 830 nm. An optical information recording medium including the optical recording layer records sub-information (BCA information) of a type different from that of main information (data information) in a sub-information region (a BCA recording region) different from a main information area (a data area) using a laser beam.