Abstract: A phase-change optical information recording medium in which information can be recorded, reproduced and rewritten and which includes a first transparent substrate having a wobbling guide groove which is spirally formed thereon at a pitch; a first dielectric layer located overlying the first transparent substrate and having an optical thickness of from 80 nm to 200 nm; a phase-change recording layer located overlying the first dielectric layer and having an optical thickness of from 20 to 50 nm when the recording layer is in an erased state; a second dielectric layer located overlying the recording layer and having an optical thickness of from 10 nm to 70 nm; a reflection layer located overlying the second dielectric layer; optionally a third dielectric layer located between the second dielectric layer and the reflection layer; and a second transparent substrate located overlying the reflection layer.

Abstract: In an information recording medium comprising at least a substrate, a recording layer, and a resin layer, the substrate is formed with at least a pit corresponding to a read only area 31 and a groove corresponding to a recording/reproducing area 32 without overlapping with each other. A reflectivity of the recording layer is specified to be more than 10%. The recording layer and the resin layer are continuously adhered over both the read only and recording/reproducing areas 31 and 32. The information recording medium is characterized in that both push-pull signal outputs T1 and T2, which are reproduced from the read only area 31 and the recording/reproducing area 32 respectively, are more than 0.1 and satisfy an inequality 1.5?T1/T2?0.5.

Abstract: An optical information recording medium includes a transparent substrate on which a recording layer, a reflection layer, a hydrophobic protective layer, a hydrophobic intermediate layer, and an ink receiving layer are successively overlaid.

Abstract: Through embodiments an optical medium and method of fabricating the optical medium including content replication deterrent features is disclosed. The medium includes protective features for preventing the unintentional activation of the content replication deterrent features by the ambient environment.

Abstract: A flexible optical disk, includes a disk substrate, wherein a rigidity of the disk is equal to or more than 5 Pa and equal to or less than 5000 Pa where the rigidity is defined as Young's modulus of the disk×(thickness of the disk/radius of the disk)3.

Abstract: Phase-change compounds, and optical storage recording media, for recording and/or storage of data, comprising such compounds, according to the formula XSbySz; wherein X is selected from the group consisting of K, Rb, Tl, Na, Li, Cs and mixtures thereof; and wherein y is about 1 or about 5, and z is about 1 or about B. Preferably, X is K, y is 5 and z is B. Also provided are optical recording media comprising a layer of the phase-change material and methods of creating a reversible phasechange by irradiating the material with a laser radiation.

Abstract: An information recording medium is provided that has high recording sensitivity for recording information and superior repeated rewriting performance. The information recording medium has at least a recording layer that is changeable between a crystalline phase and an amorphous phase by applying a laser beam or electric current and a dielectric layer. The dielectric layer contains at least C, Si, Sn and O. Alternatively, the information recording medium includes at least two information layers with at least one of the information layer including at least a recording layer that is changeable between a crystalline phase and an amorphous phase by applying a laser beam or electric current and a dielectric layer. The dielectric layer contains at least C, Si, Sn and O.

Abstract: In an optical disk of the invention composed of two substrates bonded to each other, the level of double refraction is set to 60 nm or less in a read-only disk, to 60 nm or less in a write-once type disk, and to 40 nm or less in a rewritable type disk, respectively.

Abstract: Provided is an optical recording medium having a recording layer, an intermediate layer, an adhesive layer and a cover sheet in this order on a substrate, wherein the thickness t1 of the intermediate layer after a high-temperature high-humidity storage test satisfies the relationship: 0.8t?t1?1.2t wherein t is the thickness of the intermediate layer before the high-temperature high-humidity storage test.

Abstract: In accordance with the invention a new optical data carrier and methods for its production are provided. The optical data carrier of the invention is characterized in that different plates have different concentrations.

Abstract: Metal alloy thin films are provided for use in the highly reflective and semi-reflective layers of optical discs. Alloys include silver alloyed with gold, palladium, copper, rhodium, ruthenium, osmium, iridium, and platinum. Other alloys include copper alloys with silver, magnesium, cadmium, aluminum, nickel, beryllium, zirconium and zinc. These alloys have moderate to high reflectivity and reasonable corrosion resistance in the ambient environment.

Abstract: A method for manufacturing a disk includes the steps of forming a disk substrate, spreading a photoreactive resin on the disk substrate, curing a part of the photoreactive resin on the disk substrate so as to form a cured-in-advance portion at a part of or all of area except an area having a transferred emboss pattern thereon, pressing a stamper against the photoreactive resin spread on the disk substrate while curing the photoreactive resin so as to transfer an emboss pattern formed on the stamper, and releasing the stamper from the photoreactive resin using an attaching portion formed between the cured-in-advance portion and the stamper as a beginning portion of the releasing.

Abstract: An optical disk according to the present invention has a guide groove formed with a width which is not less than 80 nm and not more than 170 nm in terms of a half-value width. A depth of the guide groove is formed within a range in which (n1?n2)·d1+n2·d2=(2m?1)·?/4 is ±15%, wherein n1 is a refractive index of a substrate, n2 is a refractive index of a recording film, ? is a wavelength of light beams used for recording and reproduction of information, d1 is a depth of the guide groove, d2 is a depth of the recording film positioned on the guide groove, and m is an integer (m=1, 2, 3, 4 . . . ).

Abstract: An optical recording medium is provided, which are capable of recording and reproducing data with reliability even when blue or blue violet laser light is used as irradiation light. The optical recording medium includes a substrate, and a recording layer formed over the substrate and having its optical characteristic changed by irradiation of the laser light. The recording layer is substantially composed of Bi and O, and the ratio of the number of the O atoms to the total number of Bi and O atoms in the recording layer is 63-73%.

Abstract: In an information recording medium comprising at least a substrate, a recording layer, and a resin layer, the substrate is formed with at least a pit corresponding to a read only area 31 and a groove corresponding to a recording/reproducing area 32 without overlapping with each other. A reflectivity of the recording layer is specified to be more than 10%. The recording layer and the resin layer are continuously adhered over both the read only and recording/reproducing areas 31 and 32. The information recording medium is characterized in that both push-pull signal outputs T1 and T2, which are reproduced from the read only area 31 and the recording/reproducing area 32 respectively, are more than 0.1 and satisfy an inequality 1.5?T1/T2?0.5.

Abstract: An optical information recording medium characterized by comprising a temperature-sensitive layer formed on a substrate, for reversibly changing in reflectance and/or transmittance with a temperature change. A temperature-sensitive layer having the property of changing in reflectance with a temperature change is used, as well as the property of changing in light interference effect with a temperature change, thereby providing an optical information recording medium capable of providing a higher, more stable reproduction signal power.

Abstract: A description is given of an optical storage system comprising an optical storage medium (1) and an optical head device (6). The medium has a substrate (2), a recording stack (3) and an optically transparent protective coating stack (4 and 5), for protecting the recording stack from impact by the optical head device (6). The protective coating stack comprises a multi-layer (4 and 5) of at least: a first layer (5) with a thickness smaller than 40 nm and a surface with a surface energy smaller than 1.5 J/m2, and a second layer (4), adjacent the first layer (5), with a Young's modulus E smaller than 10 GPa and larger than 0.001 GPa. This combination of layers (4 and 5) is very resistant to damage caused by mechanical impact of the optical head device (6). No lubricants are required.

Abstract: In an information recording medium, a Bi—Ge—Te material is adopted as a phase-change recording layer material. A C—Ta—O material is used for at least any one of first and second boundary layers which are in contact with a recording layer.

Abstract: A super resolution information storage medium includes: a substrate; a first super resolution layer which is formed over the substrate; a second super resolution layer which is formed over the first super resolution layer; and an insertion layer which is disposed between the first and second super resolution layers.

Abstract: A beer mat having a compact disc and a beer-mat body, whereby the main surface of the beer-mat body has been provided with a flat recess, whose depth corresponds at least to the thickness of the compact disc, but less than the thickness of the beer-mat body outside of the recess, whereby the compact disc has been inserted into the recess, and with a cover film overspanning the recess and bonded to the main surface of the beer-mat cover outside of the recess, and whereby the perimeter line of the cover film runs outside of the perimeter line of the recess but within the perimeter line of the beer-mat body, so that a ring absorption area is formed.

Abstract: An optical recording medium includes a substrate 11 with a concave and convex shape for dividing a track area formed on its surface, an optical recording layer 12 having a compound consisting of at least tin (Sn), nitrogen (N) and oxygen (O) formed on the surface in which the concave and convex shape is formed and a light transmission layer 13 formed on this optical recording layer 12. Then, a compound composition SnxNyOz of tin (Sn) nitrogen (N) and oxygen (O) comprising the optical recording layer 12 is selected so as to satisfy 30<x<70 (atomic %), 1<y<20 (atomic %) and 20<z<60 (atomic %). According to this arrangement, the optical recording medium can improve jitter caused when Sn is used as a recording material.

Abstract: An optical information storage medium includes a first substrate, a reflective layer and a second substrate. In this case, the reflective layer is disposed above the first substrate. The second substrate is disposed above the reflective layer. The material of the second substrate is sucrose.

Abstract: It is an object of the present invention to provide an optical recording medium containing a substrate, and a reflective layer, a second dielectric layer, a recording layer and a first dielectric layer which are disposed over the substrate in this order, wherein the recording layer contains a phase-change recording material containing any one of GeSbSnMn and GeSbSnMnGa, and the second dielectric layer contains an oxide of two or more elements of Nb, Si and Ta.

Abstract: In an information recording medium comprising at least a substrate, a recording layer, and a resin layer, the substrate is formed with at least a pit corresponding to a read only area 31 and a groove corresponding to a recording/reproducing area 32 without overlapping with each other. A reflectivity of the recording layer is specified to be more than 10%. The recording layer and the resin layer are continuously adhered over both the read only and recording/reproducing areas 31 and 32. The information recording medium is characterized in that both push-pull signal outputs T1 and T2, which are reproduced from the read only area 31 and the recording/reproducing area 32 respectively, are more than 0.1 and satisfy an inequality 1.5?T1/T2?0.5.

Abstract: One side of a substrate film 11 is coated with a coating composition containing (A) a reactive particle produced by chemically bonding an organic compound having at least one polymerizable unsaturated group in its molecule to an inorganic oxide particle, (B) a monomer or oligomer of an organic compound having at least two polymerizable unsaturated groups in its molecule, (C) an organic compound with a weight average molecular weight of at least 1500 and having at least one polymerizable unsaturated group in its molecule, and, if desired, (D) a siloxane compound having a dimethylsiloxane skeleton, and the coating composition is cured by irradiation with ionizing radiation to form a hard coat layer 12 with a thickness of 2 to 20 ?m. This provides a hard coat film having adequate surface hardness and suppressed warpage.

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: To provide an optical recording medium and the like that is adapted to higher density and higher speed recording of 8 times or more than that of DVD (about 28 m/sec or more) and that exhibits superior repeating and reservation properties. An optical recording medium is provided that comprises a substrate, and a recording layer, wherein at least one of recording, reproducing, erasing, and rewriting of information is carried out by means of reversible phase changes at marks on the recording layer, the reversible phase changes at marks are induced between crystalline and amorphous states by laser irradiation, the length of the respective marks is 0.4 ?m or less in the traveling direction of the laser irradiation, and the recording layer has a composition expressed by the formula: In?Sb?, wherein ? and ? are atomic percent of the respective elements; 0.73??/(?+?)?0.

Abstract: The invention relates to an optical recording medium comprising a substrate, a recording layer and optionally one or more reflecting layers, wherein the recording layer comprises a compound of formula (I). For the detailed definitions of the further substituents, see the description. Recording and playback are effected especially at a wavelength of from 300 to 500 nm, for example using a blue laser. The recording and playback quality is excellent and allows a high storage density even at high speeds.

Abstract: The main object of the present invention is to provide a recording medium which makes high densification of information possible, particularly a write-once-read-many optical recording medium having good recording signal characteristics to a wide range of recording powers. The present invention is one to accomplish the above object by providing a recording medium having a recording layer, whereby recording is carried out by heating the recording layer, characterized in that the recording layer contains a substance A which decomposes at a temperature which the recording layer reaches when heated for recording, and a substance B which does not undergo a chemical reaction or phase change at a temperature which the recording layer reaches when heated for recording.

Abstract: An optical information recording method including recording information at a linear velocity of at least 14 m/s to an optical information recording medium including a substrate and a dye-containing recording layer formed on the substrate. The dye has an endothermic peak when subjected to differential thermal analysis under a flow of nitrogen gas.

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: A stamper for making a read-only optical disk includes an irregular pattern for forming embossed pits based on recording information and an irregular pattern for forming dummy irregularities. The irregular pattern for the embossed pits is arranged in a region corresponding to an information area for recording information in the read-only optical disk. The irregular pattern for the dummy irregularities is arranged in a region corresponding to an area between the information area and the outer periphery of the disk.

Abstract: A double sided optical disc includes a first record carrier having a light transmitting base board, a first reflecting layer formed on the base board and a first protective layer formed on the first reflecting layer; and a second record carrier having a light transmitting cover, a second reflecting layer formed on the cover and a second protective layer formed on the second reflecting layer. The first record carrier is united to the second record carrier through an adhesive layer for uniting the first protective layer to the second protective layer. The total thickness of the first record carrier and the second record carrier that are united together is not longer than 1.4 mm and the thickness of the light transmitting base board of the first record carrier is not shorter than 1.1 mm. Thus, recording surfaces having different specifications are provided on respective surfaces to improve a utility.

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: A silver-based alloy thin film is provided for the highly reflective or semi-reflective coating layer of optical discs. Elements that can be added to silver to produce useful silver alloys include zinc, aluminum, copper, manganese, germanium, yttrium, bismuth, scandium, and cobalt. These alloys have moderate to high reflectivity and reasonable corrosion resistance in the ambient environment.

Abstract: An optical disc of one embodiment of the invention is disclosed that includes a data side and a marking surface. Information is digitally storable on the data side. A marking is opto-mechanically writable on the marking surface. The marking surface includes a pre-written marking.

Abstract: An optical information medium having a light transmission layer obtained by curing a composition containing a urethane di(meth)acrylate (A) of the formula (I) and the other urethane di(meth)acrylate (B), and having a tensile elastic modulus of 600 to 1300 MPa at 25° C. and a light transmittance of 80% or more at wavelength of 400 nm (in the formula, R1=an alicyclic diisocyanate residue, R2=an alkylene group or an organic group containing a cycloalkyl group or ester bond, R3=H or methyl group.

Abstract: This invention discloses a novel rewritable phase-change recording medium for optical data storage, which is based on the GaSbTe ternary alloy system. The designed compositions reside on the Sb7Te3—GaSb and Sb2Te3—GaSb pseudo-binary tielines, and the claimed region can be expressed by the formula (SbxTe100-x)1-z(GaySb100-y)z, 35?x?80, 40?y?50, 0.05?z?0.9. The crystallized phase of the GaSbTe films is a single phase after laser annealing, and the crystal structure is hexagonal with continuous variation in lattice constants. The lattice parameters, a is from 4.255 ? to 4.313 ? and c is from 11.200 ? to 11.657 ?, corresponding to the c/a ratio 2.60 to 2.73. The crystallization kinetics shows increased crystallization temperature (181 to 327° C.) and activation energy (2.8 to 6.5 eV) with increasing GaSb content.

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

Abstract: A disc-shaped optical recording medium formed by carrying out a film formation process on a disc-shaped substrate material and completed by forming a center hole at the last step is manufactured in a manner such that no eccentricity will occur when the recording medium is loaded onto a drive. At the last step of an optical disc manufacturing process, i.e., at the time of opening a hole in the center part 26 of the disc-shaped substrate material 12 formed with at least a resin layer on one side thereof, the center part 26 is removed in a manner such that the diameter of the chucking center hole 28 is larger on the disc-shaped substrate material 12 side than on the light transmitting resin layer 22 side of the disc-shaped optical recording medium 30, thereby manufacturing the disc-shaped optical recording medium 30.

Abstract: A multi-stack optical data storage medium for rewritable recording by a focused laser-light beam, the medium having a substrate with deposited on aside thereof: a first recording stack comprising a phase-change type recording layer at least one further recording stack comprising a phase-change type recording layer, a transparent spacer layer adjacent each further recording stack. The further recording stack is sufficiently transmissive to ensure proper sensitivity for reading and recording in the first recording stack. For this purpose, at least one indium tin oxide layer is present in at least one of the further recording stacks. The indium tin oxide layer further ensures proper cooling behavior of the recording layer of the further recording stack in order to obtain sufficient recording performance in the farther recording stack.

Abstract: An information storage medium reduces low frequency noise, and an apparatus records and/or reproduces information thereon. The information storage medium includes a substrate; a recording layer formed on the substrate and including at least two materials in which the materials chemically react with each other due to an incident beam thereon having a write power and form a recording mark; and a super resolution reproduction layer formed on and/or under the recording layer and having a property in which optical characteristics of a partial area of a spot due to the incident beam are changed. The apparatus to record and/or reproduce information on the information storage medium includes a pickup unit having a light source, an objective lens to form a beam spot on the information storage medium, and a photodetector; a signal processor; and a controller.

Abstract: An optical recording medium including a recording layer which includes a reversible phase-change recording material, the recording layer being capable of writing information therein, reading written information therefrom, and rewriting written information by utilizing the reversible phase change of the phase-change recording material, wherein when a recording mark formed in the recording layer is repeatedly read 5000 times, using a continuous wave laser beam having such an intensity Pr that satisfies the condition of 1.1?R?2.0, in which R is ?repeat/?1 as defined in the specification, the optical recording medium satisfies a relationship of d1>dow as defined in the specification. The phase-change recording material, a method of producing the optical recording medium, and a method of writing information in the optical recording medium, reading written information therefrom and rewriting written information therein are proposed.

Abstract: An optical disk of a system wherein a recording layer is to be irradiated throughout a thin film cover layer with a laser beam, wherein a hard coat layer (W) is formed on the thin film cover layer, and the hard coat layer (W) is made of a cured product of coating composition (X) comprising a polyfunctional compound (A) having at least two active energy ray curable polymerizable functional groups, a water and oil repellency-imparting agent (B), an active energy ray polymerization initiator (C) and a colloidal silica (D) having an average particle size of from 1 to 200 nm, provided that the water and oil repellency-imparting agent (B) is a water and oil repellency-imparting agent (B-T) having, in one molecule, a moiety (b-1) excellent in compatibility with the polyfunctional compound (A) and an active energy ray curable functional group (b-3).

Abstract: An optical disk of a system wherein a recording layer is to be irradiated with a laser beam through a thin film cover layer, wherein on the surface of the thin film cover layer, a hard coat layer is formed which is made of a cured product of an active energy ray curable composition comprising a polymerizable monomer (A), a colloidal silica (B), a lubricity-imparting agent (C) and an active energy ray polymerization initiator (D), as components. The lubricity-imparting agent (C) contains a lubricity-imparting agent (C-T) having, in one molecule, a moiety (c-1) exerting lubricity, a moiety (c-2) excellent in compatibility with the polymerizable monomer and an active energy ray curable functional group (c-3). In the optical disk of the present invention, the hard coat layer formed on the surface of the thin film cover layer is excellent in abrasion resistance, transparency and long-term surface lubricity.

Abstract: A phase-change optical recording medium has a first information layer including a phase-change optical recording film arranged in a position close to the light incident side, a second information layer including another phase-change optical recording film arranged in a position remote from the light incident side and an interlayer separating film arranged between the first information layer and the second information layer, in which at least one of the first information layer and the second information layer includes a noise reduction film in contact with the interlayer separating film. The noise reduction film is formed of SiOx (1?x?2) or SiOC.

Abstract: A multilayer optical information recording medium includes optical information recording layers, and dielectric multilayer reflecting layers provided under the optical information recording layers respectively. Each of the dielectric multilayer reflecting layers includes: a laminate of low refractive index films and high refractive index films; and a variable refractive index film exhibiting change of refractive index induced by laser beam irradiation. Each of the dielectric multilayer reflecting layers is provided so that reflectance of a portion used for reading/writing information by condensed laser beam irradiation is high while transmittance of the other portion is high. It is possible to reduce intensity of laser beam to be irradiated to the medium.

Abstract: An optical recording medium comprising: a substrate 11; and a recording layer 12, formed on substrate 11; and characterized in that recording layer 12 contains palladium oxide as the main component and contains oxygen at an amount of 19 atom % to 61 atom %.

Abstract: An optical recording medium includes a support substrate and two information recording layers, an information recording layer close to a light incidence plane through which a laser beam is projected including a first dielectric film, a second dielectric film and a recording layer disposed between the first dielectric film and the second dielectric film and a thickness of each of the first dielectric film and the second dielectric film being determined so as to be equal to or larger than D21 and equal to or smaller than D22, where D21 is smaller than D2, D22 is larger than D2, and D21 and D22 are determined in such a manner that the dependency X of light transmittance of the information recording layer close to the light incidence plane on the wavelength of a laser beam is smaller than 1.

Abstract: The present invention provides an optical disk 9 with a duplication preventing function, reproducing system 47 for the optical disk 9, optical disk reproducing method, method of fabricating an optical disk original record, and illegal program operation stopping method. An area in which a CP signal 24 is recorded is made after a signal having a constant pattern in the optical disk, the CP signal 24 being produced such that the center of an eye pattern is shifted from the center of the amplitude. In the reproducing system, CP signal arrangement information 25 or a CP preceding signal 26 is detected, before an offset voltage is applied to a threshold value to be used in demodulating an RF signal into a digital signal so that the threshold value varies, thus normally reproducing the signal in which center of the eye patter is shifted from the center of the amplitude. The reproducing system has a function whereby the reproduction is stopped when a predetermined offset signal is not reproduced.