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: 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.

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: An optical disk from which recorded data are read out by means of light irradiation has a substrate having recording pits as data on a surface thereof, and stacked films formed on the substrate. The stacked films contain a super-resolution film of a polymer matrix and semiconductor particles having an organic group covalently bonded thereto, and a reflective film reflecting light. The super-resolution film and the reflective film are provided in this order from a light incident side.

Abstract: A method for fabricating an optical recording medium is provided. A dye layer is formed on a molded substrate by spin-coating. A reflection layer is formed on the dye layer by sputtering so that the optical disc has enough reflection rate. The dye layer comprises a cyanine type dye and an azo metal chelate compound selected from the formula (I): wherein M is a metal ion; R1 is a hydrogen atom, a linear or branched alkyl group containing 1 to 6 carbon atoms, amino group, alkyl amino group or toluidinyl group; R2 is a hydrogen atom, a hydroxyl group, a halogen atom, an ether group, an ester group or a linear or branched alkyl group containing 1 to 6 carbon atoms; R3 is a hydrogen atom or a linear or branched alkyl group containing 1 to 6 carbon atoms; R4 is a hydrogen atom, a halogen atom or a linear or branched alkyl group containing 1 to 6 carbon atoms; A1 is a heterocyclic derivative group constituted by carbon atoms and nitrogen atoms.

Abstract: Optical data carrier comprising a preferably transparent substrate which may, if desired, have previously been coated with one or more reflection layers and to whose surface a light-writeable information layer, if desired one or more reflection layers and if desired a protective layer or a further substrate or a covering layer have been applied, which can be written on or read by means of blue, red or infrared light, preferably laser light, where the information layer comprises a light-absorbent compound and, if desired, a binder, characterized in that at least one cyanine dye is used as light-absorbent compound.

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 medium can be recorded at a high linear velocity of at least 10 m/s while maintaining an excellent light stability and favorable reflectance. A recording medium is constructed of a recording layer on a substrate, the recording layer including a first dye with a maximum absorption wavelength in a thin-film state of 450 nm to 620 nm inclusive as a first dye and being formed so as to include a second dye with an extinction coefficient of at least 0.5 for a recording wavelength. In this case, it is preferable for the second dye to have a maximum absorption wavelength of 620 nm to 750 nm inclusive in a thin-film state.

Abstract: An optically recorded article comprising a pattern of isomerized material in two isomeric forms in a matrix, wherein one of the isomeric forms is capable of being converted to the other form by one-electron oxidation and wherein said matrix was polymerized in-situ.

Abstract: The invention discloses new benzoindole styryl compounds and its use for a high-density optical recording medium. The invention uses the dyes of the new benzoindole styryl compounds to form the recording layer of high-density recording media. The new benzoindole styryl compounds are easy to prepare and purify, so they are cheaper when comparing to the compounds generally used in high-density optical recording media. The benzoindole styryl compounds has a maximum absorption for the light wavelength in the range of 500 nanometers to 700 nanometers. The benzoindole styryl compounds also have high sensitivity and chemical stability for light and heat. Using the new benzoindole styryl compounds to form a high-density optical recording medium can match up with the short-wavelength laser beam for high-density optical recording media and have the advantage of a stable quality.

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: The present invention is directed to a three-dimensional memory apparatus for storing information in a volume comprising of an active medium. The active medium is capable of changing from a first to a second isomeric form as a response to radiation of a light beam having an energy substantially equal to a first threshold energy. The concentration ratio between a first and a second isomeric form in any given volume portion represents a data unit. The active medium in the memory apparatus comprises of diarylalkene derivatives, triene derivatives, polyene derivatives or a mixture thereof. The invention is further directed to means for reading the data units from the isomeric states of the active medium in different portions of said active medium where the two isomeric forms have a substantially different absorption coefficient for absorbing energy of a second threshold energy. Reading may also be carried out by measuring the scattering pattern of the two isomeric forms.

Abstract: The present invention provides an optical recording medium including a recording layer and an optical reflection layer formed on a substrate. The recording layer contains at least one particular polymethine pigment selected from polymethine pigments having 1 to 4 carbons in the methine main chain, so as to obtain a sufficient recording sensitivity for a red wavelength range of light.

Abstract: The present disclosure relates to a limited play optical storage media and a method for limiting access to data thereon. This storage media comprises: an optically transparent substrate; a reflective layer; an oxygen penetrable UV coating disposed on a side of the substrate opposite the reflective layer; and a reactive layer disposed between the UV coating and the substrate, the optical storage media having an initial percent reflectivity of about 50% or greater and a subsequent percent reflectivity of about 45% or less.

Abstract: The invention relates to a method for the recording of data, in particular, personal data on and/or in a data support, by means of electromagnetic radiation. A corresponding data support is made ready, on and/or in which a dye is at least locally provided and said dye is irradiated by means of said electromagnetic radiation of at least one wavelength range, such that a change in the color of the dye by bleaching occurs in the region of the irradiation. Said color change may be determined by machine and/or by the human eye. An improved counterfeiting and manipulation security for the data support is thus achieved.

Abstract: A recordable digital video disc preferably employable for information recording method using a laser beam having a wavelength of 600–700 nm, composed of a transparent disc substrate provided with a spiral pregroove, a recording dye layer placed in the pregroove, and a light-reflecting layer, arranged in order, wherein the recording dye layer has a thickness in the range of 40% to 90% of a thickness corresponding to an optical path which gives the first minimum reflectance, the optical path giving the first minimum reflectance being determined from a reflectance curve which is prepared using recordable digital video discs composed of the same disc substrate, the same recording dye layer having varying thickness, and the same light-reflecting layer.

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: 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 is described, having suitable recording characteristics over a wide range of recording linear speed and fitting with recording/reproduction apparatuses of CD-R specifications. The optical recording medium includes a substrate having at least a light absorbing layer thereon, which is mainly composed of three phthalocyanine compounds (I), (II) and (III). Each of the phthalocyanine compounds (I) and (II) has a thermal decomposition temperature of from 200° C. to 300° C., and has a different light absorption ability against light having a wavelength of 780 nm. The phthalocyanine compound (III) has a thermal decomposition temperature of from 300° C. to 350° C.

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: Compositions and methods for production of color images using leuco dye-containing color forming compositions are described. The color forming composition can include a color forming leuco dye, an activator having at least one acid group which can be protected by a protection leaving group; and a deprotecting agent configured for removing the protection leaving group upon application of energy in the form of heat or light.

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: An optical recording medium having at least a recording layer 11 and a light transmitting layer 13 formed on a substrate 10, in which the recording layer 11 is made of an organic material for absorbing an incident light of wavelength of 360 nm to 460 nm, and inducing physical change or chemical change to vary the refractive index, the light transmitting layer 13 is 10 ?m to 177 ?m in thickness, the relation between absorption coefficient “k” and pyrolysis temperature Tdec of organic material is 950(° C.)<(Tdec (° C.)?20)/k<4100° C.??(1), and the absorption coefficient “k” is k>0.0.

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: The present invention provides a reactive adhesive formulation for use in a limited play data storage medium, the reactive adhesive formulation including at least one adhesive material, at least one reactive material disposed within the at least one adhesive material 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 resorcinol, 4-hexylresorcinol and/or polyhydroxystyrene.

Abstract: Embodiments of optical discs and methods for making the same are disclosed. In one embodiment, the optical disc comprises: at least two plastic substrates comprising a bonding layer and a data layer disposed therebetween, wherein at least one of the substrates is a read side substrate comprising greater than or equal to about 0.05 wt % colorant, based upon the total weight of the read side substrate, and wherein the read side substrate has a UV Bonding Index of greater than or equal to about 0.5. One method for making the optical disc comprises: forming a first plastic substrate comprising greater than or equal to about 0.05 wt % colorant, based upon the total weight of the first plastic substrate, wherein a UV Bonding Index of the first plastic substrate is controlled to be greater than or equal to about 0.5, disposing a data layer between the first plastic substrate and a second substrate, bonding the first plastic substrate to the second plastic substrate with a bonding layer, and curing the bonding layer.

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: An optical recording disk includes at least a recording layer containing an organic compound containing a porphyrin system dye as a primary component and a light transmission layer which transmits a laser beam having a wavelength of 390 to 420 nm on a support substrate in this order, the porphyrin system dye having a minimal value nmin of a refractive index n within a wavelength region of 390 nm to 420 nm and a refractive index n equal to or lower than 1.2 with respect to the laser beam having the wavelength of 390 to 420 nm and absorbing the laser beam having the wavelength of 390 to 420 nm to be melted or decomposed, whereby the refractive index thereof changes and data are recorded in the optical recording disk. According to the thus constituted optical recording disk, it is possible to record data therein using a bluish-violet laser beam having a wavelength of 390 to 420 nm and reproduce data therefrom using a bluish-violet laser beam having a wavelength of 390 to 420 nm.

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: A protective agent for protecting a print formed on a printing object comprises a high-volatile organic solvent as a dispersion medium and non-water family high polymer emulsion liquid including synthetic resin particles as a dispersoid. This protective agent is sprayed onto a print formed on a printing object by a spray method and then dried. For example, an oil-based first print layer 2 is formed on a surface of an information record member 1, an oil-based second print layer 3 is formed on at least a part of the upper surface of the first print layer 2, and the aforementioned protective agent is applied on the upper surface of the second print layer 3 and dried to form a protective layer 4. Thus, the print will not disappeared even if a hands touches or water is adhered, and no bad influence will be given to the substrate material since the protective agent is excellent in quick-drying property.

Abstract: Compositions and methods for production of color images using leuco dye-containing color forming compositions are described. The color forming composition can include a color forming leuco dye, a metal salt activator, a suppression agent configured for inhibiting the activity of the metal salt activator until application of energy in the form of heat or light, and an initiator precursor. The initiator precursor is capable of liberating scavenger species which reduce the inhibiting action of the suppression agent. The color forming compositions can be a single phase mixture of a leuco dye, metal salt activator, suppression agent, and initiator precursor which are stable under ambient conditions and form a colored composition upon application of energy.

Abstract: An optical information recording medium includes a substrate having a thickness of approximately 1.0 mm to 1.2 mm, with a spiral pre-groove being formed at a predetermined area on the substrate excluding a central hole and an outer periphery. Successively disposed on the area at which the pre-groove is formed are a light-reflective layer, a recording layer that can record information when irradiated with light having a wavelength range of 380 nm to 500 nm, a protective layer for protecting the recording layer, an adhesive layer made of a photocurable resin that has been cured by being irradiated with visible light, and a thin transparent protective layer.

Abstract: A near-field optical recording medium comprises a recording layer capable of writing, reading and erasing information using an evanescent light, the evanescent light having a beam spot size smaller than the wavelength of a source light, wherein the recording layer is a stable amorphous layer mainly comprising a photochromic compound having a glass transition point of 55° C. or higher and a molecular weight of 3000 or less.

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 limited play optical storage medium for data is provided in the present invention. The limited play optical storage medium for data 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 with an oxygen permeability in a range between about 0.01 Barrers and about 1.35 Barrers at 25° C. wherein the second substrate is between the reactive layer and a laser incident surface.

Abstract: The invention provides an optical recording medium having excellent weatherability and a process for producing the same. The optical recording medium is provided with an organic dye layer, a reflecting layer and a protective layer in this order on a light-transmittable substrate. The organic dye layer contains an organic solvent in an amount of 2% to 15% by weight based on the organic dye. A solution, prepared by dissolving an organic dye in an organic solvent, is applied onto the light-transmittable substrate by a spin coating method to form an organic dye layer. A reflecting layer is formed on the organic dye layer without performing a drying treatment of the organic solvent in the organic dye layer, followed by forming the protective layer on the reflecting layer. The result is an optical recording medium containing an organic solvent in an organic dye layer in an amount of 2% to 15% by weight based on an organic dye.

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: 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 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: An optical recording medium includes a) a dielectric layer, b) a recording layer, and c) a reflective layer, which are stacked on a surface of a substrate in the described order or stacked on the surface in the order of b) the recording layer, a) the dielectric layer, and c) the reflective layer. The recording layer contains a mixed nickel oxides which decomposes to release a gas and becomes transparent upon heating.

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.