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 including a metal complex compound comprising an azo compound having a coupler component with a Meldrum's acid structure and a diazo component with a nitrogen-containing heterocyclic aromatic ring structure, and a metal ion coordinated to the azo compound.

Abstract: [Problem]: An optical recording medium having a capability of recording and/or reading high density optical information using a short wavelength laser light is provided. [Means to Address the Problem]: The optical recording medium has a capability of recording and/or reading high density optical information using a short wavelength laser light having a wavelength of 350 nm to 530 nm. The optical recording medium has a recording layer containing a metal complex compound and formed on a substrate. The metal complex compound is composed of a cyclic ?-diketone azo compound represented by the general formula (I) or general formula (II) and a divalent metal ion coordinated to the cyclic ?-diketone azo compound.

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: By use of a substrate which can be stably formed and has a relatively small groove depth, a very high density optical recording medium having good recording/reading characteristics is provided. In an optical recording medium of a surface incidence type, in which a reflective layer, a recording layer containing a dye as a main component and a cover layer are sequentially formed on a substrate having guide grooves formed therein, a guide groove part on a far side from a plane of incidence of a recording/reading light beam on the cover layer is set as a recording groove part, and reflected light intensity in a recorded pit portion formed in the recording groove part is increased by a phase shift and is set higher than reflected light intensity in unrecorded.

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: [Problem]: An optical recording medium having a capability of recording and/or reading high density optical information using a short wavelength laser light is provided. [Means to Address the Problem]: The optical recording medium has a capability of recording and/or reading high density optical information using a short wavelength laser light having a wavelength of 350 nm to 530 nm. The optical recording medium has a recording layer containing a metal complex compound and formed on a substrate. The metal complex compound is composed of a cyclic ?-diketone azo compound represented by the general formula (I) or general formula (II) and a divalent metal ion coordinated to the cyclic ?-diketone azo compound.

Abstract: An information recording method allows optical information having a recording mark length smaller than a spot diameter of laser light to be recorded on an optical recording medium having a recording layer, at high density by laser light pulse application. The information recording method has: a power calibration step of determining a recording power for recording a signal having a predetermined signal length in the recording layer using the laser light; and a complementing step of complementing, based on the recording power determined in the power calibration step, a recording power for recording a signal having a signal length equal to or less than ½ of the spot diameter of the laser light in the recording layer using the laser light. In the information recording method, for example, an extremely small mark, such as a 2T signal, can be precisely formed.

Abstract: Problem: To provide an optical recording medium having a recording layer improved in light stability that is capable of writing and reading of high-density optical information by a short-wavelength laser beam. Means for Solving the Problems: There is provided an optical recording medium with a recoding layer comprising an organic dye compound, wherein the recording layer contains a metal complex compound composed of a pyridone azo compound represented by the following the general formulas [I] to [III] and a divalent ion of metal coordinated to it such as nickel, cobalt, iron, zinc, copper, manganese and the like, wherein the pyridone azo compound contains a 6-hydroxy-2-pyridone structure as a coupling component and isoxazole, 1,2,4-triazole or pyrazole structure as a diazo component. (In the general formulas [I] to [III], R1 to R10 each is independently a hydrogen atom or monovalent functional group.

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

Abstract: To provide an optical recording medium capable of high density recording or readout of optical information by a laser beam having a short wavelength. An optical recording medium comprising a substrate and a recording layer formed on the substrate, capable of recording or readout of information by irradiation with light, wherein the recording layer contains a 7-aminocarbostyril compound of the following formula (I): in the formula (I), X is an oxygen atom or a sulfur atom, R1 is a hydrogen atom or a linear or branched alkyl group which may be substituted, R6is a linear or branched alkyl group which may be substituted, and n=1 to 4.

Abstract: By use of a substrate which can be stably formed and has a relatively small groove depth, a very high density optical recording medium having good recording/reading characteristics is provided. In an optical recording medium of a surface incidence type, in which a reflective layer, a recording layer containing a dye as a main component and a cover layer are sequentially formed on a substrate having guide grooves formed therein, a guide groove part on a far side from a plane of incidence of a recording/reading light beam on the cover layer is set as a recording groove part, and reflected light intensity in a recorded pit portion formed in the recording groove part is increased by a phase shift and is set higher than reflected light intensity in unrecorded.

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

Abstract: An information recording method allows optical information having a recording mark length smaller than a spot diameter of laser light to be recorded on an optical recording medium having a recording layer, at high density by laser light pulse application. The information recording method has: a power calibration step of determining a recording power for recording a signal having a predetermined signal length in the recording layer using the laser light; and a complementing step of complementing, based on the recording power determined in the power calibration step, a recording power for recording a signal having a signal length equal to or less than ½ of the spot diameter of the laser light in the recording layer using the laser light. In the information recording method, for example, an extremely small mark, such as a 2T signal, can be precisely formed.

Abstract: A metal chelate compound obtained from an azo compound of the following formula [a] or [b] and a metal salt: wherein each of A2 and A3 is a residue forming, together with the carbon atom and the nitrogen atom to which A2 or A3 is bonded, a heterocyclic ring which may have a substituent, B1 is a residue forming, together with the carbon atoms to which B1 is bonded, an aromatic or heterocyclic ring which may have a substituent, and Y is a C1-6 linear or branched alkyl group substituted by at least two fluorine atoms.

Abstract: A high-density optical disk comprises a transparent substrate having a guide groove having a depth of 100 to 200 nm, width of 0.2 to 0.4 &mgr;m arranged with a track pitch of 0.7 to 1.0 &mgr;m. A recording layer is made of an organic pigment exhibiting a specific main weight reduction in a thermogravimetric analysis and a specific exothermic peak in a differential thermal analysis.

Abstract: A sulfonamide compound of the formula (1): wherein X is a hydrogen atom, an alkyl or alkoxy group which may be substituted, or a halogen atom, Y Is an alkyl group having at least two fluorine atoms, and each of R1 and R2 which are independent of each other, is an alkyl group which may be substituted, or R1 may be bonded to X or R2 to form a ring.

Abstract: An optical recording medium having a recording layer containing an organic colorant as the main component, whereby recording is carried out by changing the reflectivity by irradiation of a laser beam for recording having a wavelength of at most 700 nm, wherein when a light having substantially the same wavelength as the laser beam for recording and having an intensity selected from a range of from 1 to 4.5 mW and a pulse length of about 382 nsec, is irradiated while moving a portion to be irradiated of the medium at a relative velocity of 0.3 m/s to the light, the time required for the reflectivity to change and reach a saturated level, is at most 130% of said pulse length.

Abstract: An optical recording medium comprising a transparent substrate and at least a recording layer containing an organic dye, a reflecting metal layer and a protective layer sequentially laminated on the substrate in this order, which has the following characteristics (a) to (c): (a) the substrate has a tracking groove with a track pitch of from 0.7 to 1.0 &mgr;m and the recording layer shows a modulation amplitude of EFM signal of at least 50% when recording is carried out by a laser beam with a wavelength of from 600 to 700 nm, and has a reflectance of from 45 to 65%; (b) in a thermogravimetric analysis of the dye, the inclination of the weight reduction to the temperature in the main weight reduction process is at least 2%/°C.; and (c) in the thermogravimetric analysis of the dye, the total weight reduction in the main weight reduction process is at least 25%.

Abstract: An azo metal chelate compound of an azo compound of the formula (I) with a metal: ##STR1## wherein A is a residue forming a heterocyclic ring together with the carbon atom and the nitrogen atom to which it is bonded, X is a residue forming an aromatic group together with the two carbon atoms to which it is bonded, R.sup.1 is an alkyl group which may be substituted, an aryl group which may be substituted, an alkenyl group which may be substituted, or a cycloalkyl group which may be substituted, Y is a hydrogen atom or a cation, and n is an integer of from 1 to 3.

Abstract: An azo metal chelate compound of an azo compound of the formula (I) with a metal: ##STR1## wherein A is a residue forming a heterocyclic ring together with the carbon atom and the nitrogen atom to which it is bonded, X is a residue forming an aromatic group together with the two carbon atoms to which it is bonded, R.sup.1 is an alkyl group which may be substituted, an aryl group which may be substituted, an alkenyl group which may be substituted, or a cycloalkyl group which may be substituted, Y is a hydrogen atom or a cation, and n is an integer of from 1 to 3.