Abstract: A sheet screen is provided on one of sides of test glass, and a projected image of the test glass is electronically and directly picked up. After tone image signals of the test glass thus picked up are binarized while modifying threshold values according to brightness of a background in the tone image, the number of fragments, the area of the greatest fragment and the length of the longest fragment are calculated. Thus, operations, such as calculating the number of the fragments, can be automatically performed by directly picking up an image of the test glass, allowing a fragmentation test to be carried out with good operability and high precision.

Abstract: An optical disc used with an optical head with a focus depth of about 2 micron meter minimizes defects and deterioration in the optical disc at the time of manufacture, during operation and storage thereof as well. The optical disc includes a pair of transparent substrates each provided with at least one layer enabling recording of information, with the pair being bonded and laminated together has an instantaneous axial acceleration<2G.

Abstract: An optical disc used with an optical head with a focus depth of about 2 micron meter minimizes defects and deterioration in the optical disc at the time of manufacture, during operation and storage thereof as well. The optical disc includes a pair of transparent substrates each provided with at least one layer enabling recording of information, with the pair being bonded and laminated together has an instantaneous axial acceleration<2 G.

Abstract: The object of the present invention is to provide an optical disc and a method of manufacturing thereof wherein defects and deterioration in the optical disc are minimized at the time of manufacture, during operation and storage thereof as well. The invention conceives an optical disc suitable for accomplishing the above object through specifications such as providing a cross-sectional structure thereof comprising a pair of transparent substrates each provided with at least one layer of a recording film formed on the surface of information patterns thereof, with the pair being bonded and laminated with an adhesive, and further providing an instantaneous axial acceleration<2 G measured at room temperatures, a skew angle<5 mrad measured at room temperatures, and a skew angle<5 mrad measured after being left for one hour as heated to 80° C. (otherwise, a shear mass<20 &mgr;m measured after being left for one hour as heated to 80° C.

Abstract: A small-sized heat resisting high voltage transformer and an ignition transformer using the high voltage transformer are provided and utilize both a heat resistant casting resin and a bobbin, which contain an inorganic filler. The high voltage transformer is capable of producing an output voltage of 10-35 kV and comprises a primary coil, a secondary coil, and a magnetic core, wherein a casting resin is injected into the coil part and subsequently cured. The casting resin and bobbin material used for making the coils have heat distortion temperature of at least 130° C., and contain an inorganic filler. The surface of the bobbin may be pretreated. Thereby, adhesion between a bobbin and a casting resin is enhanced to ensure operating properly under the sever heat cycle condition and provide a small-sized heat resistant high voltage transformer.

Abstract: The object of the present invention is to provide an optical disc and a method of manufacturing thereof wherein defects and deterioration in the optical disc are minimized at the time of manufacture, during operation and storage thereof as well. The invention conceives an optical disc suitable for accomplishing the above object through specifications such as providing a cross-sectional structure thereof comprising a pair of transparent substrates each provided with at least one layer of a recording film formed on the surface of information patterns thereof, with the pair being bonded and laminated with an adhesive, and further providing an instantaneous axial acceleration<2 G measured at room temperatures, a skew angle<5 mrad measured at room temperatures, and a skew angle <5 mrad measured after being left for one hour as heated to 80.degree. C. (otherwise, a shear mass<20 .mu.m measured after being left for one hour as heated to 80.degree. C.

Abstract: The object of the present invention is to provide an optical disc and a method of manufacturing thereof wherein defects and deterioration in the optical disc are minimized at the time of manufacture, during operation and storage thereof as well. The invention conceives an optical disc suitable for accomplishing the above object through spcifications such as providing a cross-sectional structure thereof comprising a pair of transparent substrates each provided with at least one layer of a recording film formed on the surface of information patterns thereof, with the pair being bonded and laminated with an adhesive, and further providing an instantaneous axial acceleration<2 G measured at room temperatures, a skew angle<5 mrad measured at room temperatures, and a skew angle<5 mrad measured after being left for one hour as heated to 80.degree. C. (otherwise, a shear mass<20 .mu.m measured after being left for one hour as heated to 80.degree. C.

Abstract: An optical disk producing apparatus produces an optical disk by bonding a pair of replica disks together. The replica disks are disposed in a sealed space to oppose to each other with a predetermined gap therebetween. The sealed space is defined by a peripheral wall and opposite ends. The peripheral wall is divided into two portions which are slidingly movable relative to each other. When the sealed space is evacuated, the two portions are moved to apply an atmospheric pressure to the replica disks, so that the replica disks are bonded together into an optical disk.

Abstract: The object of the present invention is to provide an optical disc, a method of manufacturing thereof and an optical reproduction apparatus including the same wherein defects and deterioration in the optical disc are minimized at the time of manufacture, during operation and storage thereof as well. The invention conceives an optical disc suitable for accomplishing the above object through specifications such as providing a cross-sectional structure thereof comprising a pair of transparent substrates each provided with at least one layer of a recording film formed on the surface of information patterns thereof, with the pair being bonded and laminated with an adhesive, and further providing an instantaneous axial acceleration <2G measured at room temperatures, a skew angle <5 mrad measured at room temperatures, and a skew angle <5 mrad measured after being left for one hour as heated to 80.degree. C. (otherwise, a shear mass <20 .mu.m measured after being left for one hour as heated to 80.degree.

Abstract: An optical disk producing apparatus produces an optical disk by bonding a pair of replica disks together. The replica disks are disposed in a sealed space to oppose to each other with a predetermined gap therebetween. The sealed space is defined by a peripheral wall and opposite ends. The peripheral wall is divided into two portions which are slidingly movable relative to each other. When the sealed space is evacuated, the two portions are moved to apply an atmospheric pressure to the replica disks, so that the replica disks are bonded together into an optical disk.

Abstract: The object of the present invention is to provide an optical disc and a method of manufacturing thereof wherein defects and deterioration in the optical disc are minimized at the time of manufacture, during operation and storage thereof as well. The invention conceives an optical disc suitable for accomplishing the above object through specifications such as providing a cross-sectional structure thereof comprising a pair of transparent substrates each provided with at least one layer of a recording film formed on the surface of information patterns thereof, with the pair being bonded and laminated with an adhesive, and further providing an instantaneous axial acceleration <2 G measured at room temperatures, a skew angle <5 mrad measured at room temperatures, and a skew angle <5 mrad measured after being left for one hour as heated to 80.degree. C. (otherwise, a shear mass <20 .mu.m measured after being left for one hour as heated to 80.degree. C.

Abstract: The object of the present invention is to provide an optical disc and a method of manufacturing thereof wherein defects and deterioration in the optical disc are minimized at the time of manufacture, during operation and storage thereof as well. The invention conceives an optical disc suitable for accomplishing the above object through specifications such as providing a cross-sectional structure thereof comprising a pair of transparent substrates each provided with at least one layer of a recording film formed on the surface of information patterns thereof, with the pair being bonded and laminated with an adhesive, and further providing an instantaneous axial acceleration <2G measured at room temperatures, a skew angle <5 mrad measured at room temperatures, and a skew angle <5 mrad measured after being left for one hour as heated to 80.degree. C. (otherwise, a shear mass <20 .mu.m measured after being left for one hour as heated to 80.degree. C.

Abstract: This invention relates to insulated wires having good heat resistance and solderability. In particular, wires coated with a polyimide resin or an imide-modified polyurethane resin are provided. They can each be produced by coating a conductor with an insulating coating composition which contains a polyamic acid represented by the following formula: ##STR1## wherein R.sup.1 means a particular tetravalent organic group, R.sup.2 denotes a specific divalent organic group, X is an alkylene or alkylenephenylene group, and n stands for a positive integer.

Abstract: The object of the present invention is to provide an optical disc and a method of manufacturing thereof wherein defects and deterioration in the optical disc are minimized at the time of manufacture, during operation and storage thereof as well. The invention conceives an optical disc suitable for accomplishing the above object through specifications such as providing a cross-sectional structure thereof comprising a pair of transparent substrates each provided with at least one layer of a recording film formed on the surface of information patterns thereof, with the pair being bonded and laminated with an adhesive, and further providing an instantaneous axial acceleration <2G measured at room temperatures, a skew angle <5 mrad measured at room temperatures, and a skew angle <5 mrad measured after being left for one hour as heated to 80.degree. C. (otherwise, a shear mass <20 .mu.m measured after being left for one hour as heated to 80.degree. C.

Abstract: This invention relates to a replica plate having a transparent plastic substrate and a photo-cured resin, and a projection type television using the replica plate. An adhesive layer comprising an acrylic or methacrylic compound is provided between a transparent plastic plate and a replica-forming photo-curable resin, whereby it is possible to enhance the adhesion between the surface of the transparent plastic plate and the photo-cured resin, and to produce a replica plate having excellent optical characteristics, good replicating properties and high reliability. The adhesive layer can be provided (1) by coating a layer containing the acrylic or methacrylic compound on the plastic plate, the compound infiltrating into the plate, or (2) by incorporating the acrylic or methacrylic compound into the photo-curable resin, the compound infiltrating therefrom into the plate; in this latter technique, the plate coated with the resin should be heated.

Abstract: A polymer excellent in transparency, mechanical properties, moisture resistance suitable for optical use is obtained by copolymerizing a (meth)acrylate compound (I) and a (meth)acrylate compound (II).

Abstract: A method for producing an optical disk base to store, record, and retrieve sounds, images, and information. An improved method for producing an optical disk base includes the steps of injecting a photo-curable resin into a cavity, curing the photo-curable resin by irradiation with light, and demolding, where the photo-curable resin is injected from an injection nozzle having an outside diameter which is substantially equal to the diameter of the center hole of the optical disk base and also having a horn-shaped opening at the forward end. The injection nozzle is arranged at the center of the optical disk base. The forward end of the nozzle is closed after injection and the photo-curable resin is irradiated with light, with the injection nozzle projected into the cavity. A liquid resin is injected in the form of uniform flow without entrapped bubbles, so that the anamolous molecular orientation is avoided and the contamination with insufficiently cured or uncured resin is also avoided.

Abstract: In an optical recording disk wherein a resin layer cured with ultraviolet radiation is provided on a surface of a transparent substrate, the present invention consists in that a material having a heat distortion temperature of at least 65.degree. C. is employed for the ultraviolet-cured resin layer. The appearance of wrinkles on a UV-cured resin surface is suppressed, whereby an optical recording disk of high carrier-to-noise ratio and long lifetime can be provided.

Abstract: An optical disc wherein a transparent base plate is made from a special light-curable resin composition comprising at least one compound of the formula: ##STR1## wherein R.sub.1 =H or methyl and n=0-5, and a photopolymerization initiator, is excellent in heat resistance, mechanical strength, moisture resistance, etc.

Abstract: The invention discloses an optical disc base plate obtained by curing with irradiation of light a light- or radiation-curable resin composition in which a photopolymerization initiator is contained in an amount of 0.5 to 5 parts by weight per 100 parts by weight of a resin composition comprising the compounds (1), (2) and (3) mixed in amounts falling in the area defined by lines A-B-C-D-E-A in the triangular diagram of FIG.