Abstract: An optical recording medium includes a recording layer and a dielectric layer formed in the vicinity of the recording layer and the dielectric layer contains an oxide as a primary component and being added with nitrogen. The thus constituted optical recording medium can exhibit excellent optical characteristics with respect to a laser beam of desired wavelength used for recording data and reproducing data.

Abstract: This invention relates to a read-only near-field optical disk using a zinc-oxide (ZnO) nano-structured thin film as the localized near-field optical interaction layer. This read-only near-field optical disk is a multi-layered body at least comprising; (a) a transparent substrate with pre-recorded pits or marks; (b) a reflection thin film; (c) a zinc-oxide (ZnO) nano-structured thin film which is capable of causing localized near-field optical interactions; (d) a first and a second protective and spacer layers formed above or below the localized near-field optical interaction layer, which are also made of transparent dielectric material. Ultrahigh density near-field optical readout can be achieved by localized near-field optical interaction between the zinc-oxide (ZnO) nano-structured thin film and the reflection layer on pre-recorded structure.

Abstract: An optical recording medium includes a substrate, a first recording layer formed on the substrate and containing an element selected from the group consisting of C, Si, Ge and Sn as a primary component, and a second recording layer located in the vicinity of the first recording layer and containing an element selected from the group consisting of C, Si, Ge and Sn and different from the element contained as a primary component in the first recording layer as a primary component. According to thus constituted optical recording medium, it is possible to optically record data therein and reproduce data therefrom by projecting a laser beam having a wavelength of 350 nm to 450 nm thereonto, which includes two or more recording layers and is capable of decreasing noise level and improving C/N ratio of a reproduced signal.

Abstract: An optical recording medium includes a substrate, a first recording layer formed on the substrate and containing an element selected from the group consisting of Si, Ge, C and Al as a primary component, and a second recording layer located in the vicinity of the first recording layer and containing Zn as a primary component, the optical recording medium being constituted to be irradiated by a laser beam projected onto the side opposite from the substrate and the total thickness of the first recording layer and the second recording layer being equal to or thinner than 30 nm. According to the thus constituted optical recording medium, it is possible to decrease a noise level and improve a C/N ratio in a reproduced signal.

Abstract: There is provided an optical recording medium having a phase-change recording layer formed based on a drastically new concept of making the content of Mn still higher than the prior art while using Sb as a main component. The optical recording medium has a recording layer composed of a plurality of elements, and the recording layer contains Sb, and also has an Mn content of more than 20 atomic % but not more than 40 atomic %, on condition that the total amount of all the elements composing the recording layer is 100 atomic %.

Abstract: An optical recordable medium at least comprises a recording layer formed on a transparent substrate. The recording layer is sequentially formed on a first transparent layer, a semi-reflective layer, a dielectric layer, a reflective layer and a material layer. When a modulated writing beam irradiates the recording layer and data is written in a recorded area, the first transparent layer and the semi-reflective layer react to form a second semi-reflective layer. When a reading light irradiates the recorded area, the light wave phase is shifted and the recorded area becomes anti-reflective.

Abstract: There is provided an optical recording medium formed based on a drastically new concept of forming a phase-change recording layer by using other elements than chalcogen. The optical recording medium has a phase-change recording layer thereof formed such that a reversible phase change of the phase-change recording layer between an amorphous phase and a crystalline phase can be utilized. The phase-change recording layer contains Sb as a main component and at least one element selected from the groups consisting of elements of other groups than group VIb and rare earth metal elements, as a sub-component.

Abstract: An optical recording medium including a substrate having guide groove thereon; a first protective layer located overlying the substrate; a recording layer located overlying the first protective layer; a second protective layer located overlying the recording layer; a third protective layer of from 2 to 9 nm thick located overlying the second protective layer and comprising Si in an amount not less than 35 atomic percent; and a reflection layer including Ag in an amount not less than 95% by weight. An overcoat layer having a glass transition temperature of from 90° C. to 180° C. is preferably formed overlying the reflection layer. A method for manufacturing the optical recording medium is also provided.

Abstract: Systems and methods are described for inhibiting the readability of an optical media due to changes in a pseudo-reflective material that composes the optical media after the optical media has been exposed to air for a predetermined time. An optical media includes a data encoded component. At least a fraction of the data encoded component transforms from a substantially optically reflective state to a substantially optically non-reflective state as at-least-in-part a function of time from an initializing event. The systems and methods provide advantages because of low cost, limited content lifetime, avoidance of rental returns and minimum changes to existing manufacturing processes.

Abstract: An optical recording medium includes a substrate, a first recording layer formed on the substrate and containing an element selected from the group consisting of Si, Ge, C, Sn, Zn and Cu as a primary component, and a second recording layer located in the vicinity of the first recording layer and containing Al as a primary component, the optical recording medium being constituted to be irradiated by a laser beam projected onto the side opposite from the substrate and the total thickness of the first recording layer and the second recording layer being equal to or thinner than 40 nm. According to the thus constituted optical recording medium, it is possible to decrease a noise level and improve a C/N ratio in a reproduced signal.

Abstract: An optical recording medium includes a substrate, a protective layer, a first recording layer containing an element selected from a group consisting of Si, Ge, Sn, Mg, In, Zn, Bi and Al as a primary component, and a second recording layer located in the vicinity of the first recording layer and containing Cu as a primary component. When the optical recording medium is irradiated with a laser beam, the element contained in the first recording layer as a primary component and the element contained in the second recording layer as a primary component are mixed by the laser beam and a region whose reflection coefficient has been changed is formed, whereby information is recorded.

Abstract: An optical information recording medium of the present invention includes at least one information layer. The information layer includes a first protective film, a first interface film, a recording film having the optical characteristics that are changed reversibly by laser beam irradiation, a second interface film, a second protective film, and a reflective film, present in the indicated order from the laser beam incident side. The first interface film includes an oxide of at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, and Si. The second interface film includes carbon or a carbide of at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, and Si.

Abstract: Problem to be solved is that when an information recording medium is repeatedly subjected to recording of information several hundreds times, the atoms in a protective layer are diffused and dissolved into a recording layer to lower a reflectivity greatly and make the medium unendurable to many times of overwriting. This problem can be solved by a medium constituted of interference layer 10, interface layer 12, phase-change type recording layer 14, protective layer 13 having a tin content of from 23.3 atomic % to 32.3 atomic %, and a heat sink layer 8 successively formed on substrate 1, as seen from a light-incidence side. By use of this medium, the dissolution of atoms can be prevented, and overwriting for many times can be achieved.

Abstract: An optical recording medium for recording and reproducing information utilizing the change of a physical property of a recording layer caused by the irradiation with light, which comprises a substrate, characterized in that the substrate comprises a hydrogenated styrene polymer having a content of nucleus-hydrogenated styrene units of 80 wt % or more, has a glass transition temperature of 110° C. or higher, has a light transmittance of 88% or more at 400 nm, and exhibits an absolute value of retardation of 30 nm or less at 0° and 30° from the normal direction of the plane thereof. The optical recording medium suitable for use in the high density optical recording capable of responding to a greater number of openings and the use of a light having a shorter wave length in an optical head.

Abstract: An optical data recording medium includes a light transmittable plastic substrate, and a recording layer formed on the plastic substrate and containing an inorganic compound body and metal particles dispersed in the inorganic compound body. The inorganic compound body is made from a material selected from a group consisting of a metal oxide and a metal nitride.

Abstract: A method for fabricating read-only copy protected optical medium comprising a light-sensitive material at positions capable of altering the data read during copying of the optical medium but permitting read of the underlying data in the reading of the optical medium.

Abstract: An optical information recording medium includes a substrate, and a record layer formed on the substrate. Information is recorded using a laser beam with a wavelength of 380 nm to 430 nm, and refraction index n and attenuation coefficient k of the record layer satisfy a relation of 3.9<n<5.6 and k>0.4 to the wavelength of 380 to 430 nm.

Abstract: Systems and methods are described for inhibiting the readability of an optical media due to changes in a pseudo-reflective material that composes the optical media after the optical media has been exposed to air for a predetermined time. An optical media includes a data encoded component. At least a fraction of the data encoded component transforms from a substantially optically reflective state to a substantially optically non-reflective state as at-least-in-part a function of time from an initializing event. The systems and methods provide advantages because of low cost, limited content lifetime, avoidance of rental returns and minimum changes to existing manufacturing precesses.

Abstract: A multilayer optical disk having an information storage layer which can as well as be reproduced by a general purpose reproducing apparatus, for example, a compact disk player, and from which information can be read from other information storage layers by using an exclusive reproducing apparatus. The method of manufacturing a multilayer disk comprises the steps of forming a first substrate having a first information storage area enabling reproduction of information therein with a first light beam having a wavelength of 770 nm to 830 nm; forming a second substrate having a second information storage area enabling reproduction of information therein with a second light beam having a wavelength of 615-655 nm but which is relatively transparent with respect to said first light beam; and bonding said first substrate to said second substrate together without said first and second said information areas facing each other.

Abstract: High density, photon-gated persistent spectral holeburning is effectuated in rare earth doped II-VI compounds such as MgS, CaS, BaS and SrS. Two-photon ionization of rare earth ions is performed, selected by a narrow band laser, producing narrow regions of reduced absorption (optical holes) in the absorption spectrum of a rare earth ion. These holes are useful for such applications as high density memory (especially, high density re-writable or photo-erasable memory), spectral holographic memory, communication, etc., no and demonstrate great survivability over reading cycles, thermal cycles and elevated temperatures. The embedment of the rare earth doped II-VI compound in a matrix comprising a polymeric material (such as PMMA), prior to the effectuation of the holeburning, may be advantageous for many embodiments. Inventive practice has successfully burned two hundred forty photon gated spectral holes in the zero phonon line (ZPL) of the 4f-5d transition of Eu2+ in a magnesium sulfide host.

Abstract: This invention is to provide a kind of near-field optical disk. This near-field optical disk is formed by a recording layer, a suitable thickness of near-field layer, a silver halide compound of light scattering layer, and a protection layer on the substrate layer in sequence. It is not necessary to increase the energy of transmitting beam for that the recording layer of this near-field optical disk and the transmitting beam has accomplished recording at a near-field distance to obtain the higher recording density.

Abstract: Optical storage media with limited useful life include a substrate having a data storage portion containing readable data. A reservoir associated with the substrate releasably retains a preselected chemical agent that interacts with the data storage portion to render it unreadable a preselected period of time after the chemical agent is released. Alternatively, the invention includes an optical storage medium including a substrate supporting a metallic data storage layer for storing optically readable data, a reservoir located in proximity to the data storage layer for storing a chemical agent in contact with the data storage layer on a first side of the reservoir, and a flexible metallic lamina in contact with the chemical agent on an opposite side of the reservoir.

Abstract: The present invention relates to an optical disk which achieves stable electrical characteristics and disk shape, and in which visible information is provided on the signal readout surface side of the disk. An optical disk is constructed by sequentially layering on the pits of a transparent disk substrate (1a), a recording layer (2a) of a translucent reflective film, an optical buffer layer (3a) formed from a light transmissive material, and a printed layer (4a) on which is printed visible information, with the visible information of the printed layer (4a) being visible from the disk substrate (1a) side of the disk. The optical buffer layer (3a) is formed at a thickness, measured in terms of optical distance (the product of multiplying the physical distance by the refractive index of the material from which the optical buffer layer is formed), of between 3 &mgr;m˜45 &mgr;m.

Abstract: A transparent coating is used on an optical information disk. The optical information disk is an injection-molded piece of clear poly-carbonate plastic and is impressed with microscopic bumps which are arranged as a single, continuous, extremely long spiral track of data. A thin, reflective aluminum layer is sputtered onto the optical information disc so that the thin, reflective aluminum layer covers the bumps. A thin acrylic layer is sprayed over the thin, reflective aluminum layer in order to protect it. The transparent coating is a composite material which is made of silica as the discontinuous phase and of a polytetrafluoro-ethylene-derived organic polymer as the continuous phase which leads to a fluorine-containing silica-based product. The transparent coating is applied by spin or dip from specific solutions at room temperature followed by a mild and short heat treatment.

Abstract: A method for processing and laser ablation marking an imagewise exposed motion picture photographic film element which comprises a support having on a front side thereof one or more image-forming units comprising at least one light-sensitive silver halide emulsion layer is described, comprising processing the film to provide a developed photographic image with at least 100 mg/m2 of retained silver halide, and subsequently laser ablation marking the film to selectively ablate portions of the image forming units from the support.

Abstract: A recording medium includes a first substance and a second substance at least in which the first and second substances undergo an oxidation-reduction reaction when an external energy is applied, thereby recording information by varying the optical characteristics. In the recording medium, the reaction of the first and second substances is suppressed, reaction which degrades the recording characteristics other than the case where the recording medium is subjected to recording. In an optical disk 100 (i.e., the recording medium), a WO3 film 2 (i.e., a second substance), a C film 3 (i.e., a third substance) and an Sn-10 atomic % Sr film 4 (i.e., a first substance) are formed successively on a substrate 1. When the recording medium is irradiated with a recording laser beam as an external energy, the WO3 forming the film 2 is reduced to WO2.

Abstract: An optical recording medium comprises a recording layer containing, as a photoresponsive material, metal chalcogenide nanoparticles, wherein the metal chalcogenide nanoparticles have an average particle size of 1 to 20 nm and have a surface modified with an adsorbable compound.

Abstract: A recording medium includes a first substance and a second substance at least in which the first and second substances undergo an oxidation-reduction reaction when an external energy is applied, thereby recording information by varying the optical characteristics. In the recording medium, the reaction of the first and second substances is suppressed, reaction which degrades the recording characteristics other than the case where the recording medium is subjected to recording. In an optical disk 100 (i.e., the recording medium), a WO3 film 2 (i.e., a second substance), a C film 3 (i.e., a third substance) and an Sn-10 atomic % Sr film 4 (i.e., a first substance) are formed successively on a substrate 1. When the recording medium is irradiated with a recording laser beam as an external energy, the WO3 forming the film 2 is reduced to WO2.

Abstract: The present invention aims to provide a resin suitable for use as a protective layer or adhesive layer formed on the surface of a metal film. A liquid oligomer having a high specific gravity of 1.10 or more is contained in a photocurable resin involved in photopolymerization of a resin composition. Upon application on a metal film 12 and photopolymerization, bulky substituents owned by the high-specific gravity liquid oligomer prevent penetration of moisture to provide a protective film 13 with low water permeability. Said high-specific gravity liquid oligomer should desirably be contained in the photocurable resin within the range from 35% by weight to 78% by weight both inclusive.

Abstract: An optical memory device and a method for manufacturing thereof. An optical memory device has at least one data layer formed on a substrate. An upper surface of the substrate is formed with a pattern comprising a plurality of regions which are capable of obtaining, when covered by a recording medium, desired optical properties different from those of the substrate. The patterned surface of the substrate is coated with the recording medium. The recording medium is removed from the patterned surface after the recording regions have obtained the desired optical properties.

Abstract: In an optical recording medium in which at least a heat diffusion layer, a first dielectric layer, an information recording layer and a second dielectric layer are formed in this order on a substrate and signals are recorded and/or reproduced by the light illuminated from the side of the second dielectric layer, it is desirable to optimize recording and/or reproducing characteristics. With this in view, an under layer 3 for optimizing surface properties of a heat diffusion layer 4 is formed between a disc substrate 2 and the heat diffusion layer 4.

Abstract: In the optical recording medium including a substrate having pregrooves, and a metal recording thin film, a buffering layer and a reflecting layer which are stacked in sequence on the substrate, the buffering layer is formed of one or more dyes having a refractive index (n) of 1.4 or more and an absorption coefficient (k) of 1.6 or less at a wavelength of 650 nm, and a refractive index (n) of 1.8 or more and an absorption coefficient (k) of 0.001 or more at a wavelength of 780 nm. Therefore, the optical recording medium is reproducible by a CD player and a DVD player. Also, due to a metal recording thin film layer formed on a substrate, the amplitude of a recording signal is increased and the optical reliability is also improved. Also, because of a thin buffering layer, the manufacturing costs can be reduced. Also, by adding a material whose weight is rapidly lost during decomposition to the buffering layer, the recording sensitivity and the optical reliability can be much improved.

Abstract: A security card is disclosed which comprises a laminate of a flexible glass layer and a support, characterised in that the glass layer has a thickness of not more than 350 &mgr;m. The thin glass layer has sufficient flexibility to allow substantial bending of the card without causing breakage of the glass. In addition, the glass layer acts as a security feature because delamination in order to falsify information stored in the card is very difficult without breaking the glass. The glass is also an efficient barrier layer protecting the information stored in the card from mechanical damage and from degradation due to permeation of gases such as oxygen or water vapour.

Abstract: A magnetic recording medium comprising first, second and third magnetic layers laminated in succession, wherein when (1) the magnetic wall energy density, saturation magnetization, magnetic wall coercivity and film thickness of the first magnetic layer at a temperature T represented by cgs unit system are defined as &sgr;1, Ms1, Hw1 (2) h1, respectively, and the magnetic wall energy density, saturation magnetization, magnetic wall coercivity and film thickness of the third magnetic layer are defined as &sgr;3, Ms3, Hw3 and h3, respectively, (3) the interface magnetic wall energy density between the first magnetic layer and the third magnetic layer is defined as &sgr;w13, and (4) the lowest temperature at which &sgr;w13 is 0 erg/cm2 is Ts, at least 2Ms1*Hw1<&sgr;w13/h1  and 2Ms3*Hw3>&sgr;w13/h3  are satisfied, at room temperature and when a suitable temperature Tp is chosen, within a temperature range greater than the temperature Ts and lower by 10° C.

Abstract: An optical information recording medium includes a first substrate; at least a first dielectric layer and a recording layer for signal recording provided on a surface of the first substrate; and a second substrate. The first substrate and the second substrate are assembled together in the state of being warped in planar symmetry and flattened. The first dielectric layer and the recording layer is interposed between the first substrate and the second substrate.

Abstract: An optical information recording medium comprising a thin plastic substrate of 0.6 mm or thinner, wherein the substrate is protected against strain without being limited by a film structure and a film formation condition. A single-layer or multilayer thin film (70) is formed on a plastic disk-like substrate having a center hole (10). This thin film (70) has a strain relief area (72) inside a recording area (71). This strain relief area (72) is formed by setting an outer diameter of an undeposited inner portion (5) to a value satisfying the following formula (1), for example: A0≦AX≦−0.172P+0.163 where A0: diameter of center hole, AX: outer diameter of undeposited inner portion, P: total strain occurring in thin film when film depositing.

Abstract: A half-transmissive film of an optical disk is formed using a Cu oxide instead of Au, while achieving similar reflectivity characteristics to those of Au. Alternatively, the half-transmissive film may comprise a compound of Cu with a corrosion-resistant material, or a stack of layers comprising a lower layer film of Cu, Ag, or Al and an upper layer film of a corrosion-resistant material. Further, the half-transmissive film may comprise ZnS.SiO2, a nitride of Ti, indium-tin-oxide, or an alloy of Au and Cu or a compound including Au and Cu.

Abstract: A recording film is formed by a vacuum film formation process. The recording film contains a substance which is thermally decomposed when a recording laser beam is irradiated thereto. When the substance is thermally decomposed by irradiation of the recording laser beam, a substance generated by the thermal decomposition is precipitated within the recording film, and therefore a change in complex index of refraction is caused predominantly over the raising deformation in the recording film. As a result, information is recorded in the recording film while causing almost no raising deformation of the recording film.

Abstract: Colloidal metal alloy compositions are prepared by chemical reduction of mixtures of at least two types of metal ions in an aqueous medium. Coating such a composition onto a support provides heat mode recording elements with improved sensitivity to laser radiation.

Abstract: A recording medium which includes a first substance and a second substance, wherein an external energy is applied to at least one of the first and second substances to react them in order to change the optical characteristics of the substances for recording information, the recording medium including: a first layer composed of a first substance including at least one of S and Se, a second layer composed of a second substance including a metal, and a barrier layer being disposed between the first and second layers, which allows the reaction between the first and second layers when laser beam for recording is irradiated as an external energy, and suppresses the reaction between the first and second layers when laser beam for recording is not irradiated. Alternatively, the recording medium can be free from the barrier layer, and the second substance can be arranged to have two or more compositionally different portions or two or more phases with a different crystalline state.

Abstract: A method for making a DVD-18 disc using primarily just conventional CD-type injection molding and sputtering equipments. Three substrates are molded. Each of two of the substrates has just one metallic information layer, with the opposite side being flat. The third substrate has two metallic information layers on its opposite sides. The three substrates are arranged in a sandwich configuration, with the substrate having two information layers being in the middle. Each of the outer substrates has a semireflective (gold) information layer that faces inwardly of the sandwich. The middle substrate has two fully reflective (aluminum) information layers. A very thin layer of glue is placed between the semireflective information layer on each of the outer substrates and one of the fully reflective information layers on the middle substrate.