Kabushiki Kaisha Toshiba

Tokyo Shibaura Denki Kabushiki Kaisha

Norio Ozawa

Nobuaki Yasuda

Yoshikatsu Takeoka

Akio Hori

Hideki Ohkawa

Motonari Matsubara

Hiroaki Yoda

Susumu Hashimoto

Yuichi Ohsawa

Michiko Hara

Naoyuki Inoue

Atsuko Iida

Yasuhisa Oana

Takeo Sakakubo

Masaki Katsura

Katsutarou Ichihara

Reiji Nishikawa

Hiroyuki Higashino

Hirosi Ohdaira

Kideki Ohkawa

Teruo Sasho

Masato Yamashita

A composite magnetic head includes a recording head and a reproducing head. The recording head may be formed below or above the reproducing head. The lower of the recording and reproducing heads includes a first electrode. In addition, a conductive layer acting as a pole structure for the recording head includes a portion defining a hole through which a second electrode is made to contact the first electrode.

Thin film magnetic recording-reproducing head having a high recording

An information storage medium consists of a polycarbonate substrate and a recording layer formed on the substrate and containing an AgTe eutectic alloy, carbon, and hydrogen. Information is recorded on the medium by forming pits in the recording layer upon radiation of a laser beam, and is reproduced by radiating a reproducing laser beam onto the recording layer in which the pits are formed and detecting reflectances.

Information storage medium

An information storage medium comprises a substrate and a recording layer formed on the substrate containing Te, Ge, C and H. The recording layer is formed by sputtering, with a Ge-Te alloy being used as a target and with a mixed gas of a noble gas and a hydrocarbon being used as a sputtering gas. The hydrocarbon content in the sputtering gas falls within a range of 3 to 35%. The composition of the target is Ge.sub.x Te.sub.100-x (where x is expressed by atomic %, and 5.ltoreq.x.ltoreq.20).

Disclosed is an optical recording medium comprising a transparent substrate having a tracking line formed therein, and a recording layer formed on that surface of the substrate in which is formed the tracking line. The recording layer consists of a low oxide of nickel. Also disclosed is an optical recording medium comprising a transparent substrate consisting of a thermoplastic resin, a thermosetting resin layer formed on each surface of the substrate, a patterned photoresist layer, said patterned photoresist layer being formed on one of the thermosetting resin layer, and a recording layer formed to cover the exposed portion of the thermosetting resin layer and the patterned photoresist layer.

Optical recording medium

An optical recording medium and methods of manufacturing the same are disclosed. The optical recording medium is provided with a transparent adhesive layer containing organic compounds such as hydrocarbon or the like that constitute resin materials, and metallic compounds whose thermal expansion coefficients are nearly equal to those of inorganic transparent materials that constitute a transparent protective layer, whereby peel-off phenomena to be caused by secular variation can be avoided.

Optical recording medium and method of manufacturing the same

An information storage medium includes a substrate, and a recording layer formed on the substrate, which contains carbon, hydrogen, and Te. The recording layer has an amorphous state wherein no peak representing the presence of a crystal is confirmed by X-ray diffractometry, and an activation energy is 1.5 eV or more, which is required to transform the state of the recording layer from the amorphous state into a crystalline state wherein peaks each representing the presence of a crystal are confirmed by X-ray diffractometry.

Information storage medium and method of manufacturing the same

A radiation-sensitive carrier body directly utilized as a stamper has a glass substrate, a first highly adhesive layer securely adhered to the substrate, a radiation-sensitive layer which discharges a gas component upon being irradiated with a laser beam and which locally forms a protuberance due to the absorbed energy, a second highly adhesive layer securely adhered to the specific material of the radiation-sensitive layer and which deforms in accordance with deformation of the layer, and a metal layer which has a high releasability to allow easy separation from a optical disk substrate material such as an acrylic material when the carrier body is used as a stamper substrate for manufacturing optical disks. A protuberance formed on the carrier body such as a continuous spiral protuberance allows formation of a corresponding spiral groove in the acrylic material, serving as a pre-track into which desired information will be digitally written by a user.

Radiation sensitive carrier body utilized as stamper structure

There is disclosed a method for manufacturing a bubble-mode optical disk having a recording layer made of a mixture of an indium oxide matrix containing indium clusters and organic clusters. The indium clusters absorb an energy of incident laser beam to heat the organic clusters which then release a gas component such that the matrix is locally deformed to form a protuberance. A plasma sputtering is used to deposit the recording layer on a disk substrate placed in a sputtering chamber. A target body used is made of indium. A low-pressure gaseous atmosphere in the chamber includes a methane series hydrocarbon gas and an oxygen gas. The gaseous atmosphere may include a hydrogen gas or a nitrogen gas.

Method for manufacturing bubble-mode optical recording media

A disk-shaped recording medium of the invention has a photosensitive recording layer formed on a substrate. Tellurium oxide clusters are dispersed in a hydrocarbon matrix of the recording layer so as to thermally stabilize the matrix. Tellurium clusters are dispersed in the matrix which is thermally stabilized by dispersion of the tellurium oxide clusters. The recording layer has excellent oxidation and heat resistance. The recording medium is manufactured by a plasma sputtering technique.

Information recording medium and manufacturing method thereof

In an optical disk, a single recording layer is formed on a transparent substrate. The recording layer has an insulative base layer in which metal clusters and organic clusters are uniformly contained. When radiation is incident on the recording layer such that the intensity of the radiation is changed in accordance with the type of recording information, the metal clusters absorb radiation energy. The organic clusters produce a gas component in accordance with a level of the radiation energy absorbed by the metal clusters, thereby causing the base layer to incur a local projection by a pressure of the gas component such that a protuberance is formed on the base layer.

Optical type information recording medium and manufacturing method

An optical information recording medium is produced by introducing a plasma-generation gas comprising hydrocarbon into a plasma-generating region provided with a metal target and a substrate. The pressure of the plasma-generating gas is maintained within a predetermined range within the plasma-generating region. Electrical power is applied to the plasma-generating gas to dissociate the gas thereby forming a plasma. The generated plasma sputters the metal target, thereby allowing the sputtered metal to be deposited on the substrate in the form of a film containing the metal and the carbon liberated from the hydrocarbon. During sputtering, the product between the density of the power applied to the electrode and the average residence time of the plasma-generating gas within the plasma-generating region is controlled within such that the product falls within the range of more than 0.5 W-sec/cm.sup.2 and less than 50 W-sec/cm.sup.2, and the partial pressure of a secondary hydrocarbon, which is different from the introduced hydrocarbon, present during the dissociation to the secondary hydrocarbon before the dissociation and after the introduction is set to range between 2 and 12.

Method of producing an optical information recording medium

Process of using radiation-sensitive carrier body to form stamper

Disclosed is a III-V Group compound semiconductor light-emitting element having a III-V Group compound semiconductor body with a p-n junction and including a p-type layer involved in forming the p-n junction; and a multi-layer electrode mounted on the p-type layer of the semiconductor body. The electrode comprises a first layer of gold alloy containing a small amount of beryllium or zinc and formed in direct contact with the p-type layer of the semiconductor body and an uppermost layer formed of gold or aluminum. A tantalum layer doped with carbon, nitrogen and/or oxygen is formed between the first layer and the uppermost layer by means of vacuum vapor deposition.

Growing community of inventors

Kawasaki, Japan

Norio Ozawa