Abstract: An optical information recording medium having a recording layer comprising a dye layer containing a trimethine-based cyanine dye having nitro group attached to a benzene ring or to a naphthalene ring, both being bonded to indole ring, is capable of minimizing the second peak in relative to the main peak shown in FIG. 1, thus enabling the spectrum consisting of a main peak and a second peak to become sharp. The recording layer is capable of performing the recording and reading with a laser beam having a wavelength falling within a range of 620 nm to 690 nm.

Abstract: An optical recording medium having a light absorption layer formed on a substrate having a spiral groove by means of the vacuum deposition and a reflective layer formed on the light absorption layer, wherein: (1) the groove of the substrate has a groove section of which cross section is a trapezoidal; (2) a ratio of a groove width (W) to a track pitch (TP) (W/TR) of the substrate falls within a range of 0.25 to 0.45; (3) a groove depth (D) is 20 to 80% of (&lgr;/4n) (wherein A is a wavelength of a laser beam, and n is a refractive index of the substrate); and (4) angles a1 and a2 formed by both side surfaces of the groove section and surfaces vertical to a groove bottom surface on cross lines between the both side surfaces of the groove section and the groove bottom surface are 45 to 80°, and a difference between a1 and a2 (a1−a2) is not more than ±10°.

Abstract: According to the present invention there is provided an imaged element comprising an optical card and underneath a layer package comprising in the order given an optional image receiving layer, a prelayer, an interlayer and a transparent support, at least the optional image receiving layer or the prelayer comprising an image, characterized in that the interlayer contains a polyurethane and a cross-linking agent.

Abstract: An information recording medium includes a substrate, a first protective layer formed on the substrate, a recording layer formed on the first protective layer, and a second protective layer formed on the recording layer. The first protective layer has a thickness in a range from 65 nm to 130 nm. The second protective layer has a thickness in a range from 15 nm to 45 nm. The recording layer has a thickness in a range from 15 nm to 35 nm and is composed of a phase-change alloy with the composition in terms of atomic percentage being represented by the formula AgaInbSbcTed where 0<a<6, 3≦b≦15, 50≦c≦65, 20≦d≦35, a+b+c+d=100. The information recording medium is configured to provide capabilities of reading, writing and overwriting of information at linear rotation rates ranging from 1.2 m/s to 11.2 m/s.

Abstract: A copper-based or silver-based alloy thin film is provided for the highly reflective or semi-reflective layer of optical discs. Alloy additions to silver include gold, palladium, copper, rhodium, ruthenium, osmium, iridium, beryllium and platinum. Alloy additions to copper include silver, cadmium, gold, magnesium, aluminum, beryllium, zirconium, and nickel. These alloys have moderate to high reflectivity and reasonable corrosion resistance in the ambient environment.

Abstract: The optical recording medium of this invention includes: a first substrate having a first information surface; a semitransparent reflection film formed on the first information surface of the first substrate; a second substrate having a second information surface; a reflection film formed on the second information surface of the second substrate; and an adhesive layer for adhering the first substrate and the second substrate so that the first information surface and the second information surface face each other, wherein the thickness of the first substrate is 0.56 mm or more, the thickness of the adhesive layer is 30 &mgr;m or more, and the total thickness of the first substrate and the adhesive layer is 0.68 mm or less.

Abstract: Disclosed is an apparatus for formation of high quality plastic sheet in a continuous fashion. Also disclosed are a variety of optical and electronic display applications for high quality plastic sheet produced in a continuous fashion.

Abstract: A luminous disk is disclosed in this invention. The luminous disk comprises a disk lamination and a light emitting lamination. The disk lamination at least comprises a substrate and a metallic reflecting layer. The light emitting lamination at least comprises an electroluminescence section having a first side plane and a second side plane, and a biasing section for applying an external electrical signal onto the first and the second side planes so as to make the electroluminescence section luminesce. Basing on the above structure, a new disk having a redoubled effect is available.

Abstract: There is provided an optical recording medium provided with at least an optical recording layer, further comprising a cured layer provided on/over outer surface of the optical recording layer and a receiving layer provided on at least a part of the cured layer. It is possible to provide an optical recording medium which allows post-processing such as printing on the cured layer which has been very difficult to be carried out so far, without degrading the reliability of the information of the optical recording medium.

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: 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: 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: An optical information recording medium of the present invention includes a transparent substrate and a multi-layered film formed on the transparent substrate. The multi-layered film includes a lower protective layer, a recording layer that changes reversibly between different states detectable optically by irradiation of light beams, an upper protective layer, an intermediate layer and a reflective layer in this order from the side near the transparent substrate. Of the upper protective layer, the intermediate layer and the reflective layer, the heat conductivity of the layer closest to the recording layer is the smallest of the three layers, and thereafter the heat conductivities of the others increase with increasing the distance from the recording layer, and the thickness of the recording layer is from 4 nm to 16 nm. In addition, a light absorption layer can be used in place of the intermediate layer.

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: The invention relates to a process for preparing molded discs suitable for use in optical information recording carriers and to the optical information recording carriers thereby obtainable. The process comprises plasticating a homopolymer or a copolymer of methyl methacrylate, injecting the plasticated homopolymer or copolymer into a mold to form a disc and removing the molded disc in a very short cycle time. Good quality discs which are particularly suitable for use in optical information recording carriers may thereby be obtained.

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 rewritable optical information medium includes a substrate coated with two carbide layers, a phase-change recording layer between two carbide layers, and a light-absorptive layer of a material like Si, Ge, Mo, or W to slow the cooling when scanned with laser light so that the medium can be used for high data rate recording. The material is capable of a user data bit rate of 50 Mbit/s.

Abstract: An optical recording medium comprising, in the following order, a substrate, a reflecting layer, a lower dielectric layer, an optical recording layer, the optical recording layer recording information by means of change in a physical property of the optical recording layer which is generated by an applied light beam, the change in a physical property of the optical recording layer being conducted at an operating temperature, and an upper dielectric layer, wherein the substrate has a thermal deformation temperature lower than the operating temperature and the optical recording medium further comprises a thermally insulating layer between the substrate and the reflecting layer.

Abstract: An optical molding material which is an aromatic polycarbonate resin pellet, wherein the amount of fine powders, produced from 5 kg of the pellets mixed in a vessel for 1 hour and having a particle diameter of 1.0 mm or less, is 300 ppm or less. The formation of carbide during molding can be suppressed by using the pellets of the present invention.