Abstract: There is provided a WORM type organic optical recording media comprising a recording layer, a reflective layer and a protective layer which are formed in sequence on a substrate, the recording layer consisting of near infrared absorbing dye able to absorb a laser beam and to generate heat and of a thermosetting or photocuring resin. The organic optical recording medium can be prevented from being rewritten by heating up to 50.degree. C. or irradiating with a UV light, said dye being capable of absorbing near infrared rays and generating heat.The medium exhibits stable reading characteristics of at least 45 dB even after irradiating with a light with a short wavelength. In addition, it also has a function of record locking by curing the resin of the recording layer, so that, once recorded, rewrite or additional recording is not allowed therein.

Abstract: A data recording method is provided in which data are recorded on a rewritable optical disk in a form of record marks which are uniform in width, and in which erasability in overwriting is much improved, thus ensuring a high-density storage of the data. A continuous strip of storage area which is smaller in width than a recording track is produced by irradiation of a first laser beam of a constant recording power, and discontinuous regions of the storage area having a width greater than the recording track are crystallized by irradiation of a second multi-value laser beam according to the data. As a result, remaining regions of the storage area are record marks used to represent the data.

Abstract: Information storage unit comprising a substrate with applied thereon a polymer layer (active polymer layer) which is polarisable by a focussed electron beam, the active polymer layer being a component of a multilayer, said multilayer comprising an active polymer layer of at least one to a maximum of fifteen electrically-insulating layers and at least one to a maximum of fifteen electrically conductive and/or semiconductive layers in an optional layer sequence, on condition that the active layer is disposed between at least one electrically-insulating layer and at least one conductive or semiconductive layer.

Abstract: An optical recording medium comprising a phase change recording layer and a dielectric layer on a substrate is improved in reliability during storage at elevated temperature when the recording layer has a composition of the following formula.[{(Ag,Au).sub.a (Sb,Bi).sub.b (Te,Se).sub.c }.sub.1-d (In,Al,P).sub.d ].sub.1-e M.sub.eLetters a to e are: 0<a .ltoreq.0.20, 0.6.ltoreq.b<1, 0<c<0.40, a+b+c=1, 0<d<0.06, and 0.ltoreq.e.ltoreq.0.20. The recording layer should have an activation energy of at least 3.0 eV as determined from the crystallization temperature versus heating rate of the recording layer sandwiched between dielectrics.

Abstract: In an optical recording medium comprising a phase change recording layer on a substrate, the recording layer is essentially of the formula:[{(Ag,Au).sub.a (Sb,Bi).sub.b (Te,Se).sub.c }.sub.1-d (In,Al,P).sub.d ].sub.1-e (Si,Ge,Sn,Pb).sub.ewherein 0.001.ltoreq.a.ltoreq.0.20, 0.40.ltoreq.b.ltoreq.0.90, 0.10.ltoreq.c.ltoreq.0.50, a+b+c=1, 0<d.ltoreq.0.06, and 0.001.ltoreq.e.ltoreq.0.10. The medium can be overwritten at a high linear velocity and remains reliable when stored at elevated temperature.

Abstract: An optical recording medium is provided with: a first substrate of optically transparent type; a first recording layer formed on one surface of the first substrate, which includes phthalocyanine dye; a second substrate of optically transparent type; a second recording layer formed on one surface of the second substrate which includes phthalocyanine dye; a first elastic body layer formed on a surface of the first recording layer at a side opposite to the first substrate; a second elastic body layer formed on a surface of the second recording layer at a side opposite to the second substrate; and a bonding layer formed between the first elastic body layer and the second elastic body layer.

Abstract: In an optical information recording medium such that a recording layer undergoing an optically detectable phase change by absorbing a laser beam is formed on a transparent substrate having geometrically concavo-convex groove tracks concentrically or spirally formed on its surface, the shapes of the groove tracks are variably determined continuously or stepwise depending on the material of the substrate, the structure of the recording layer, and the radial locations of the tracks so that the thermal diffusivity of heat generated in the recording layer becomes larger in an inner part than in an outer part whereby the differences of recording characteristics between in an inner part and in an outer part are suppressed, and the effective recording area is enlarged.

Abstract: An optical disk substrate formed substantially of an aromatic polycarbonate from an aromatic dihydroxy component containing at least 20 mol % of 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane,wherein:(A) the aromatic polycarbonate has a specific viscosity of 0.2 to 0.5,(B) the aromatic polycarbonate shows a water absorption percentage of 0.2 % by weight or less,(C) the aromatic polycarbonate has an oligomer content of 10 % or less, and(D) the number of undissolved particles having a diameter of 0.5 .mu.m or greater is 25,000 pieces or less per g of the polycarbonate resin, and the number of undissolved particles having a diameter of 1 .mu.m or greater is 500 pieces or less per g of the polycarbonate resin, and an optical disk from the above substrate.

Abstract: A magneto-optical recording medium having an improved durability or reliability is obtained by providing a protecting layer of an alloy of titanium with one or more of chromium, rhenium and tantalum. This titanium alloy protecting layer has an improved resistance to oxygen, water, chlorine, and acids, etc. and provides an improved resistance to the environment and attacks from the synthetic resin substrate or other layers constituting the medium, such as a dielectric layer and a reflecting layer.

Abstract: There is disclosed an optical recording medium for high density recording without degradation of reproducing output signals. The optical recording medium includes a transparent substrate made of resin having an information recorded portion on which optically readable information signals are recorded, a thermochromic layer provided over the transparent substrate, the thermochromic layer having a larger light transmittance when the thermochromic layer has a higher temperature than a threshold value by absorbing heat off a laser beam spot and the thermochromic layer having a smaller light transmittance when the thermochromic layer has a lower temperature than the threshold value by being cooled down, and a reflecting layer provided on the thermochromic layer, wherein a heat radiating layer made of transparent inorganic material is further provided in contact with the thermochromic layer so as to absorb heat generated in the thermochromic layer by being irradiated with the laser beam spot.

Abstract: A light reflecting and heat dissipating material which is capable of reflecting light and dissipating heat transmitted thereto from a layer in contact with or adjacent to the material to cool the layer is composed of an alloy represented by formula (I):Ag.sub.x Pd.sub.1-x (I)wherein 0.6.ltoreq..times..ltoreq.0.85. An optical information recording medium for recording information, reproducing and erasing recorded information is composed of a substrate, a recording layer formed thereon and a light reflection and heat dissipation layer composed of the above light reflecting and heat dissipating material formed on the recording layer.

Abstract: Flexible digital optical media, such as optical tapes, are provided with an aqueous-applied backing layer which provides excellent performance with regard to runnability, scratch resistance, abrasion resistance, frictional properties and curl characteristics. The backing layer comprises a film-forming water-dispersible polymeric binder and water-dispersible static-dissipative filler particles and a water-dispersible lubricant is either incorporated within the backing layer or forms a thin film over the surface of the backing layer.

Abstract: An optical information recording medium is configured so that grooves and lands formed spirally or concentrically on a disk substrate are used as recording tracks. Identification signal areas are provided in which identification signals including positional information are formed in advance on the disk substrate. Information signal areas are formed separately from the identification signal areas so that information signals are recorded by irradiation with a light beam. The identification signals are formed on the grooves and lands not independently of each other, but so that each identification signal is formed so as to be shared by a respective adjacent groove and land. The period of arrangement of the identification signals in the radial direction of the recording tracks is twice the period of the recording tracks and crosstalk at the time of reproduction of the identification signals is suppressed.

Abstract: An optical disk is disclosed which includes a substrate and a reflector layer disposed on the substrate. At least one temperature sensitive layer disposed on the reflector layer, the sensor material being selected such that its reflectivity changes as a function of the disk temperature. Finally, a transparent overcoat over the substrate or reflector layer disposed so that incident light passes through the transparent overcoat and interacts with the temperature sensitive layer so that it provides a reflected light component, the intensity of which is temperature dependent.

Abstract: A magnetic recording medium comprising a non-magnetic transparent support, a magnetic layer, and a conductive intermediate layer formed between the non-magnetic transparent support and the magnetic layer, the conductive intermediate layer comprising, as major components, powder of conductive metal or metal compound and a binder resin, wherein:the binder resin of the intermediate layer contains from 10 to 200 .mu.eq/g of --SO.sub.3 M group, --COOM group, --PO.sub.3 M.sub.2 group, or --NH.sub.3.sup.+ X.sup.- group, where M is a hydrogen atom, an alkali metal atom, or an alkaline earth metal atom, and X is a monovalent anion, andthe ratio of the content of the powder of the conductive metal or metal compound to that of the binder resin, based on weight, in the conductive intermediate layer is from 8 to 13, and a recording/reproducing method.

Abstract: A formazan metal complex dye is contained as a light absorbing dye in a recording layer to construct an optical recording medium. The formazan metal complex dye has high solubility and a relatively-low thermal decomposition temperature and the recording medium exhibits high sensitivity, especially high recording sensitivity, and improved light resistance. The formazan metal complex dye can be used as a photo-stabilizer in an optical recording medium. The formazan metal complex dye is also effective for stabilizing conventional dyes against light.

Abstract: A description is given of an optical information carrier comprising a substrate (1), a thin reflective layer (5), a dielectric layer (7), a phase-change recording layer on the basis of GeTeSe (9), a dielectric layer (11), an opaque metal reflective layer (13) and a protective layer (15). The information carrier can be inscribed, erased and read by means of a laser-light beam a and, in the inscribed state, complies with the CD-industrial standard. The recording layer (9) comprises an alloy having the composition Ge.sub.x Te.sub.y Se.sub.z, in atom %, wherein47.ltoreq.x.ltoreq.5317.ltoreq.y.ltoreq.4112.ltoreq.z.ltoreq.30andx+y+z.gtoreq.96 and, preferably, equal to 100.

Abstract: An optical recording medium includes a recording layer, and a masking layer which is converted to a state having small absorption at the wavelength of a reproducing beam due to progress of decoloration caused by a thermal reaction upon irradiation with the reproducing beam, or due to facilitation of decoloration caused by a photon mode photochromic reaction through temperature rise upon irradiation with the reproducing beam.

Abstract: A phase change optical recording medium which includes 1) a substrate having a planar surface; and 2) a plurality of discrete data recording points deposited upon the substrate. The discrete data recording points are formed from a phase change material which changes from a state of a first relative order to a state of a second relative order and visa versa upon the application of optical beam energy. Preferably the phase change material forming the plurality of discrete data recording points is deposited within individual cavities embossed into the surface of the substrate. More preferably the individual cavities are cylindrical or parabolic (bowl shaped) cavities having their central axis perpendicular to the plane of the surface of the substrate.

Abstract: An optical recording medium is provided with a masking layer on a side of a recording layer for receiving a reproducing beam. The masking layer is prepared from that containing photochromic dye molecules having absorption at the wavelength of the reproducing beam and causing a photon mode reaction by absorbing the reproducing beam to be reduced in absorption.

Abstract: The playback of a compact disc is enhanced by adhering to the compact disc an annular ring to increase the frictional engagement between the disc and the spindle upon which it turns. The playback is further enhanced by adhering a layer of soft, flexible material to dampen vibrations caused by the variations in speed by which the compact disc turns.

Abstract: There is disclosed a recordable optical element that has a substrate and on the surface of the substrate, a recording layer and a light reflecting layer. The recording layer has a material with the formula Te.sub.a Ge.sub.b C.sub.c H.sub.d O.sub.e wherein a, b, c, d, and e are atomic percents and (c+d)>40, d>10, a>5, b>5, and e.gtoreq.0 such that a+b+c+d+e=100; and the reflecting layer and the recording layer being selected such that the element R.sub.max or R.sub.min (element reflectivity) is about or greater than 70% at about 780 nm.

Abstract: An optical information handling device in which reflectivity of the conventional reproduction-only type optical disk is lowered to 60% or less and is made equal to the reflectivity of write-once type and rewritable type optical disks, whereby interchangeability in these of these disks is possible.

Abstract: The present invention provides an information recording medium including a first recording film formed on a substrate and having an amorphous phase made of an alloy containing at least Ge and Te, and a second recording film formed on the first recording film and made of a material with a relatively large light absorption coefficient, wherein the alloy of the first recording film exhibits a Raman scattering spectrum having scattering peaks at 140 to 160 cm.sup.-1 and 120 to 130 cm.sup.-1 and no scattering peaks at 100 to 110 cm.sup.-1, and recording is performed by changing optical characteristics by alloying the materials of the first and second recording films by radiating recording light on the first and second recording films.

Abstract: A magneto-optical disc is fabricated by forming a first dielectric film, a recording film of a rare earth element-transition element alloy, and a second dielectric film on a transparent substrate in the described order and further forming an intermediate film between the recording film and the second dielectric film. The second dielectric film contains at least one metal element and nitrogen. By depositing Ti, Cr or Nb to form an intermediate film of 1-28 .ANG. thick, the disc is improved in magnetic field sensitivity and reliability. By depositing Co or Ni to form an intermediate film of 1-18 .ANG. thick, the disc is improved in magnetic field sensitivity and reproduction stability.

Abstract: An optical recording medium having a recording layer and a reflective layer closely stacked on a substrate, wherein recording is carried out by directing recording light to the recording layer to form pits and reproduction is carried out by directing reproducing light to the recording layer. The recording layer contains a light absorbing dye, typically cyanine dye and a bisphenylenedithiol copper complex quencher in either independent form or ionically bonded form. The quencher characterized by a low coefficient of extinction can be added in a sufficient amount to provide the recording layer with light resistance while maintaining recording/reproducing performance.

Abstract: An optical recording medium comprising a transparent substrate; a recording layer on the transparent substrate; a metal reflective layer; and one or more protective layers. These layers are laminated successively on the transparent substrate. The outermost protective layer is formed of an ultraviolet curable resin containing an organic filler and/or an inorganic filler having water absorbency and/or oil absorbency. The protective layer has a printable surface permitting writing characters with writing instruments or ink jet printers.

Abstract: An optical recording medium comprising a recording layer on a substrate and an intermediate layer between the substrate and the recording layer exhibits high reflectance and corrosion resistance when the intermediate layer comprises silicon, aluminum, oxygen, nitrogen, and at least one element selected from the group consisting of yttrium, lanthanide elements and actinide elements, and contains 0.1 to 2 atom % of the element and 20 to 90 atom % of silicon and nitrogen combined or 2 to 35 atom % of the element and 20 to 95 atom % of silicon and nitrogen combined.

Abstract: A record blank for use in optical recording is formed by disposing in laminate form on a substrate a recording layer and a supplementary record layer, optionally with a separating layer interposed between the recording layer and the supplementary record layer. On irradiation with a recording light beam having a prescribed wavelength, in accordance with recording information, the recording layer and supplementary record layer locally form a co-melted mixture state (optically through breakage of the separating layer, if present) thus resulting in an optically detectable change in the record blank detectable by a reproducing light beam which has a wavelength the same as or different from the wavelength of the recording light beam.

Abstract: A phthalocyanine dye of specific structure represented by the following general formula (1) or (2): ##STR1## where Y is O or S attached to the phthalocyanine ring, Z is the group of atoms recurred to complete a carbon or heterocyclic ring together with C, A.sub.1 is a monovalent substituent bulkier than a hydrogen atom, and each of X.sub.1 and X.sub.2 is H or a monovalent substituent or, in the alternative, X.sub.1 and X.sub.2, taken together, form a single bond, ##STR2## where Y and Z.sub.1 have the same meanings as defined for Y and Z in formula (1), All is a monovalent substituent having a branched alkyl group, which is attached to the ring completed by Z.sub.1, and s1 is the number of A.sub.11, is used for the recording layer of an optical recording layer. This phthalocyanine dye is unlikely to attack a substrate material such as PC, can be handled with ease, and has a high solubility in a coating solvent advantageous for film formation, for instance, an alcoholic solvent, e.g.

Abstract: An optical information medium has on a substrate (2) with information-carrying pits (21), a light transmittance control layer (3) including a lower dielectric layer (31), a mask layer (32) and an upper dielectric layer (33). The mask layer has an original state before irradiation of reading light. Upon irradiation of a reading light beam to define a beam spot, the mask layer undergoes a crystal-to-crystal transition in a region (H) of the beam spot depending on the intensity distribution of the beam spot. Multiple reflection condition changes in the transition portion so that the beam spot contributing to read-out is limited to the transition or transition-free region (H or L). The transition temperature is in the range of 200.degree. to 450.degree. C. The mask layer returns to the original state after passage of the beam spot. The invention is also applicable to an optical recording medium having a recording layer above or below the transmittance control layer.

Abstract: The recording method and apparatus according to this invention is an "optical recording method utilizing a simulated photon echo" in which information is recorded by irradiating data and record excitation lights at the same time or at different times on the same location of a recording medium, and in which the delay time of a record excitation light electric field and a data light electric field is recorded as the information by use of a common incoherent light split into two equal parts: the data light and the record excitation light. In the reproducing method and apparatus according to this invention, reproducing excitation and probe lights are illuminated on the recording medium and the stimulated photon echo light emitted from the medium by illumination of the reproducing excitation light overlaps the probe light. The "stimulated photon echo" reproducing the information is utilized by converting the synthetic light obtained from the overlap into an electrical signal at a photo detector.

Abstract: An optical information reproducing apparatus having an optical recording medium in which information is recorded in a state that it is optically reproduced, and an optical head for reproducing the recorded information from the recording medium while moving relatively to the recording medium. In the apparatus, images are formed on the recording medium by two laser beams emitted from a light source of the optical head, and the difference between the two laser beams transmitted through the recording medium or reflected by the recording medium is detected.

Abstract: An optical information recording medium is disclosed. The optical information recording medium has a transparent substrate having pits and lands corresponding to information signals formed therein, and a reflective layer formed on the transparent substrate. The reflective layer is composed mainly of a dye material and a polymeric material and has a reflectance of 15 to 25%. The polymeric material forming the reflective layer is a silicon varnish.

Abstract: In a magnetooptical recording medium comprising a first dielectric layer, a recording layer, a second dielectric layer, a metal reflective layer, and a protective coat on a substrate, magnetooptical recording is carried out in a magnetic field modulation mode using recording light. The first dielectric layer is thinner than the thickness corresponding to the primary minimum reflectivity in the reflectivity versus thickness curve of dielectric layer measured at the light wavelength. This provides an increased recording sensitivity and an increased recording power margin over which recording/reproducing operation can be carried out at low error rates and high resolution.

Abstract: In a magnetic field modulation type overwrite magneto-optical recording-reproducing system for effecting the recording of information on a magneto-optical recording medium with the bottom surface of a magnetic head floated and moved relative to a protective film formed on the surface of the magneto-optical recording medium, the surface roughness .alpha. of the bottom surface of the magnetic head represented by the center line average peak height (R.sub.pm) and the surface roughness .beta. of the protective film of the magneto-optical recording medium satisfy the relational expression that 0.15 .mu.m.ltoreq.(.alpha.+.beta.).ltoreq.1.0 .mu.m.

Abstract: An optical information medium comprises an optically transparent substrate and a protective layer formed on the substrate for protecting a record portion so that information which is optically readable by means of a laser beam can be recorded. A hydrophilic film is formed at a side opposite to a side through which reproduction light of the optically transparent substrate is passed. The film has a hydrophilic surface on which an aqueous printing ink is fixable. Printing is possible on the hydrophilic surface by use of an ink jet printer. A method for printing on the hydrophilic surface is also described.

Abstract: The prevention of counterfeiting of currencies, passports, cheques, bank cards, credit cards, optical disks and the like is addressed by introducing thin film structures having both optically-variable security properties and encoded optical data decodable by optical means. The thin film structures comprise a substrate and a multilayer interference coating carried by the substrate, producing an inherent color shift with a change of viewing angle. The multilayer interference coating has a dielectric material which is transparent and the recording layer made of a light absorbing material, a crystalline-structural changing material or a magneto-optic material. The encoded data is in the form of bar codes or digital data. The information is encoded by photolithographic means or by optical recording means. The encoded data is retrieved by an optical recording system having a light source and an optical guiding system and a light detector.

Abstract: An optical recording element having a transparent substrate and on the surface of said substrate, a recording layer and a light reflecting layer wherein recording layer comprises a dye selected from the group consisting of cationic azocyanine dyes and mixtures of such dyes and the unrecorded layer is such that the real part of the refractive index (N) at 780 nm is at least 1.8 and the imaginary part (k) is 0.01 to 0.15.

Abstract: An optical recording element having a transparent substrate and on the surface of said substrate, a recording layer and a light reflecting layer wherein recording layer comprises a mixture of a metallized formazan dye and cyanine dye and the unrecorded layer is such that the real part of the refractive index (N) at 780 nm is not less than 1.8 and the imaginary part (k) is not greater than 0.2.

Abstract: A dual layer pre-recorded optical disc includes a transparent substrate, a partially reflective layer, a transparent spacer layer, and a highly reflective layer. One pattern of data pits is provided on the substrate, adjacent the partially reflective layer, and another pattern of data pits is provided on the spacer layer, adjacent the highly reflective layer. The partially reflective layer may be made of silicon carbide. A substrate-incident beam can be used to read data encoded in either data pit pattern depending on which layer the laser is focused upon. The dual layer disc has twice the data storage capacity of conventional single layer discs.

Abstract: The present invention provides a method for internally damping a rotatable storage article which is subject to resonant vibrations. More specifically, the present invention provides a method of improving the damping properties of a rotatable storage article by introducing a viscoelastic material as an inner layer(s) of the rotatable storage article. The invention also provides the damped rotatable storage articles themselves.

Abstract: In an optical recording disk comprising a reflective layer in close contact with a recording layer, the recording layer contains a phthalocyanine dye and a second dye having a lower heat decomposition temperature than the phthalocyanine dye. By virtue of a depression of heat decomposition temperature, recording sensitivity is improved.

Abstract: An optical recording medium has a substrate and a recording film, which containes coloring matter, provided on the substrate. The recording film is irradiated with a laser beam passing through the substrate so that substances of the coloring matter are aggregated with each other.

Abstract: An optical information recording medium is disclosed which includes a substrate, and an information recording layer provided on the substrate and containing a specific metallophthalocyanine having a substituent which prevents the molecular association of the metallophthalocyanine and which contains at least one of O, S and N atoms.

Abstract: A magnetic recording film and a magneto-optic recording system utilizing films. The film includes light and heavy rare earth elements and transition metal elements. The system can include dielectric layers and low magnetic coercivity layers in addition to the recording layer.

Abstract: A method and apparatus for recording and playing back of a permanent digital information on a recording medium consisting of an insulating and a conductive layers of material, by creating spots of increased conductivity in the insulating layer.

Abstract: A phase change type optical recording medium has a recording layer of a recording material containing elements A, B, and C wherein A is Ag and/or Au, B is Sb and/or Bi, and C is Te and/or Se. Information is recorded by directing a light beam to the recording layer to form recorded marks therein such that the recorded marks are amorphous or microcrystalline while an unrecorded portion of the recording layer remains crystalline, and the A concentration of the unrecorded portion is at least 0.5 atom % higher than the A concentration of the recorded marks. C/N and modulation factor are improved and such improvements are kept even after hot humid storage.

Abstract: A phase change type optical disk includes a transparent substrate, a recording layer, a first transparent protection layer, a reflective layer, and a transparent interference layer. The recording layer is formed above the transparent substrate to cause a reversible phase change between a crystalline state and an amorphous state. The recording layer causes a phase change upon being irradiated with a laser beam, thereby recording, reproducing, and erasing information. The first transparent protection layer is formed on the recording layer to protect the recording layer. The reflective layer is formed above the recording layer to reflect light transmitted through the recording layer and causes the reflected light to be incident on the recording layer. The transparent interference layer is formed between the first protection layer and the reflective layer to cause light beams reflected by the reflective layer to optically interfere with each other.

Abstract: There is disclosed an organic optical recording medium with high data storage density, high data rates and long data archival capabilities, useful as a medium for recording a variety of information or pictures.In a preferred embodiment, the optical recording medium according to the present invention comprises a substrate, a reflective layer, a charge-generating layer containing at least one charge-generating material, a charge-transferring layer containing at least one charge-transferring material, a recording layer containing at least one electric field-discoloring element, a plurality of spacers, an air layer and a protective layer.A laser beam is absorbed to the charge-generating material contained in the charge-generating layer, to generate charges, which are subsequently transferred to the surface of the recording layer by the charge-transferring layer.With the influence of the charge generated, the illuminated area having the charges puts on a color different from that in the other areas.