Hitachi, Ltd.

Hitachi Maxell, Limited

Hitachi Chemical Company, Ltd.

Other

Hitachi Maxwell, Ltd.

Ryoichi Sudo

Hiroaki Miwa

Tetsuo Tajima

Eiji Koyama

Fusaji Shoji

Hitoshi Yokono

Takeshi Watanabe

Shinkichi Horigome

Masaaki Okunaka

Tokio Isogai

Mitsuo Yamazaki

Toshimasa Ishigaki

Issei Takemoto

Akira Gotoh

Yasuhiko Uehara

Etsuji Iwami

Toshiaki Taii

Michio Ooue

Shuhei Nakamichi

Hirohumi Izumi

Makoto Kobata

Norio Ohta

Yutaka Sugita

Yasuo Hira

Mitsuo Nakatani

Yoshinori Miyamura

Toshio Niihara

Kenkichi Suzuki

Kazutoshi Kobayashi

Fumio Kataoka

Hiroaki Hachino

Mitsuru Ura

Kishiro Iwasaki

Makoto Iida

Toshimasa Miura

Kenji Tochigi

Masayoshi Kitadani

Kouji Oikawa

Saori Matsuda

Chiyoko Iwano

Hiroyuki Onodera

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.

Optical disc

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&deg; C. (otherwise, a shear mass<20 &mgr;m measured after being left for one hour as heated to 80&deg; C.), and still further by utilizing a reaction adhesive the hardness of which after cure is between A30 and A80 in Shore hardness. On the other hand, preferred methods of manufacturing optical discs suitable for implementing the object of the invention were set forth, which utilize reaction adhesives having a Shore hardness after cure between A30 and A80.

Method of manufacturing optical discs

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&deg; 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.

High voltage transformer and ignition transformer using the same

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&lt;2 G measured at room temperatures, a skew angle&lt;5 mrad measured at room temperatures, and a skew angle &lt;5 mrad measured after being left for one hour as heated to 80.degree. C. (otherwise, a shear mass&lt;20 .mu.m measured after being left for one hour as heated to 80.degree. C.), and still further by utilizing a reaction adhesive the hardness of which after cure is between A30 and A80 in Shore hardness. On the other hand, preferred methods of manufacturing optical discs suitable for implementing the object of the invention were set forth, which utilize reaction adhesives having a Shore hardness after cure between A30 and A80.

Optical recording and reproduction apparatus

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&lt;2 G measured at room temperatures, a skew angle&lt;5 mrad measured at room temperatures, and a skew angle&lt;5 mrad measured after being left for one hour as heated to 80.degree. C. (otherwise, a shear mass&lt;20 .mu.m measured after being left for one hour as heated to 80.degree. C.), and still further by utilizing a reaction adhesive the hardness of which after cure is between A30 and A80 in Shore hardness. On the other hand, preferred methods of manufacturing optical discs suitable for implementing the object of the invention were set forth, which utilize reaction adhesives having a Shore hardness after cure between A30 and A80.

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.

Optical disk producing apparatus

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 &lt;2G measured at room temperatures, a skew angle &lt;5 mrad measured at room temperatures, and a skew angle &lt;5 mrad measured after being left for one hour as heated to 80.degree. C. (otherwise, a shear mass &lt;20 .mu.m measured after being left for one hour as heated to 80.degree. C.), and still further by utilizing a reaction adhesive the hardness of which after cure is between A30 and A80 in Shore hardness. On the other hand, preferred methods of manufacturing optical discs suitable for implementing the object of the invention were set forth, which utilize reaction adhesives having a Shore hardness after cure between A30 and A80.

Optical reproduction apparatus

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 &lt;2 G measured at room temperatures, a skew angle &lt;5 mrad measured at room temperatures, and a skew angle &lt;5 mrad measured after being left for one hour as heated to 80.degree. C. (otherwise, a shear mass &lt;20 .mu.m measured after being left for one hour as heated to 80.degree. C.), and still further by utilizing a reaction adhesive the hardness of which after cure is between A30 and A80 in Shore hardness. On the other hand, preferred methods of manufacturing optical discs suitable for implementing the object of the invention were set forth, which utilize reaction adhesives having a Shore hardness after cure between A30 and A80.

This invention is related to an optical data recording medium of a high reliability and a large capacity, preventing moisture absorption and swelling of a resin layer formed on one side of a transparent substrate, and related to a method for manufacturing thereof wherever the optical data recording medium comprises at least a transparent substrate, a transferred layer of a preformat pattern formed on the transparent substrate and a thin film layer formed on the transferred layer wherein at least the surface of the transferred layer in contact with the transparent substrate is made of a resin layer composed of an ultraviolet ray curable resin resulting in an optical data recording medium having a reduced absorbing moisture of the transferred layer thereof and wherever the ratio of swelling (.DELTA.d/d) is restricted to 0.1% or less.

Optical data recording medium

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 &lt;2G measured at room temperatures, a skew angle &lt;5 mrad measured at room temperatures, and a skew angle &lt;5 mrad measured after being left for one hour as heated to 80.degree. C. (otherwise, a shear mass &lt;20 .mu.m measured after being left for one hour as heated to 80.degree. C.), and still further by utilizing a reaction adhesive the hardness of which after cure is between A30 and A80 in Shore hardness. On the other hand, preferred methods of manufacturing optical discs suitable for implementing the object of the invention were set forth, which utilize reaction adhesives having a Shore hardness after cure between A30 and A80.

Disclosed are a novel azide compound represented, for example, by the formula, ##STR1## wherein R.sub.f represents a fluoroalkyl or fluoroalkylpolyether group, ##STR2## wherein R represents a divalent organic group having an ester bond, and R.sub.f ' represents a fluoroalkylpolyether group, and a novel diacylhydrazine compound having a fluoroalkylpolyether group in the side chain and lubricants containing them. When this lubricant is coated onto the carbonaceous protective film of magnetic recording media and reacted by the action of light or heat, it strongly bonds or adheres to the protective film. Thus, the durability of the lubricant improves, as a result of which a high-density magnetic recording medium having a high reliability and long life can be obtained.

Diacylhydrazine photo-reactive compounds

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.

Insulating coating composition, solderable insulated wires, production

Method of manufacturing an optical disc

This invention is related to an optical data recording medium of a high reliability and a large capacity, preventing moisture absorption and swelling of a resin layer formed on one side of a transparent substrate, and related to a method for manufacturing thereof whatever the optical data recording medium comprises at least a transparent substrate, a transferred layer of a preformat pattern formed on the transparent substrate and a thin film layer formed on the transferred layer wherein at least the surface of the transferred layer in contact with the transparent substrate is made of a resin layer composed of an ultraviolet ray curable resin resulting in an optical data recording medium having a reduced absorbing moisture of the transferred layer thereof and whatever the ratio of swelling (.DELTA.d/d) is restricted to 0.1% or less.

Optical data recording medium and manufacturing method thereof

Growing community of inventors

Yokosuka, Japan

Ryoichi Sudo