Hitachi, Ltd.

Hitachi Maxell, Limited

Hitachi Computer Peripherals Co., Ltd.

Hitachi Instrument Engineering Co., Ltd.

Hiroaki Koyanagi

Yoshio Sato

Nobuyoshi Tsuboi

Norifumi Miyamoto

Hiroyuki Minemura

Hiroshi Sasaki

Satoshi Shimada

Hideki Nihei

Tetsuo Ito

Tetsuo Kobayashi

Masahiko Ibamoto

Hideo Tanabe

Isamu Yuito

Makoto Morijiri

Atsumi Watanabe

Eiji Ashida

Haruko Tanaka

Shinji Ohyama

Manabu Sato

Akira Taniyama

Yasuo Morooka

Moriaki Fuyama

Shinji Narishige

Takahiro Nakayama

Kanji Kawakami

Shigeru Tadokoro

Ryuji Watanabe

Kunihiro Tamahashi

Nobumasa Nishiyama

Sayaka Shinomoto

Tadashi Imanaka

Kouichi Hoashi

Kouji Takai

Fumiomi Ueda

Yukio Sasada

Satoshai Shimada

Takeshi Mizumura

Ryuichiroh Tamochi

A magnetic domain controlling film for controlling the magnetic domain of a magnetoresistive film is formed by the patterning technique on a lower insulating film formed on a lower shield film. The magnetoresistive film is formed on the magnetic domain controlling film for converting a magnetic signal from a magnetic recording medium into an electrical signal using the magnetoresistive effect. A resist pattern is formed by the lift-off method on the magnetoresistive film in such a fashion as to leave a region of the magnetoresistive film corresponding to the tracks of the magnetic recording medium. A magnetoresistive element is formed by ion milling leaving only the portion of the magnetoresistive film corresponding to the tracks.

Method of fabricating a magnetoresistive thin-film magnetic head

A slider including a recording and reproducing separation type magnetic head includes that a proximal end of a first lead-out conductor is connected to a proximal end of a central winding portion of a coil sued for record, a distal end of the first lead-out conductor is connected to one terminal used for the record; a proximal end of second lead-out conductor is connected to a proximal end of the winding coil, and extended to an opposite direction against the first lead-out conductor along the upper surface of the slider, a distal end of the second lead-out conductor is connected to another terminal used for the recording device; a proximal end of a third lead-out conductor is connected to a reproducing device; a proximal end of a fourth lead-out conductor is connected to the reproducing device; the third lead-out conductor is extended along an air bearing surface of the slider in a lateral direction; the fourth lead-out conductor is extended along the air bearing surface of the slider in a direction opposite to the lateral direction; and the respective distal ends of the third and fourth lead-out conductors are connected to one and another terminals for the reproduction, making such an integrated circuit and the like connected to the terminals to be readily standardized and making an electrode for a reproducing device short.

Recording/reproducing separation type magnetic head

A personal information display system is provided with a portable information display device for reading information to be used from a storage medium, a communication network for transmission of information, input/output apparatus for input/output of information, an input/output control apparatus connected between the communication network and the input/output apparatus, an information control apparatus having a hierarchical memory connected to the communication network, and an information output apparatus connected to the information control apparatus to transfer information to the storage medium of the portable information display device.

Personal information display system for serving large capacities of

A magnetic domain controlling film for controlling the magnetic domain of a magnetoresistive film is formed by a patterning technique on a lower insulating film formed on a lower shield film. The magnetoresistive film is formed on the magnetic domain controlling film for converting a magnetic signal from a magnetic recording medium into an electrical signal using the magnetoresistive effect. A resist pattern is formed by the lift-off method on the magnetoresistive film in such a fashion as to leave a region of the magnetoresistive film corresponding to the tracks of the magnetic recording medium. A magnetoresistive element is formed by ion milling leaving only the portion of the magnetoresistive film corresponding to the tracks. An insulating layer is formed on the resist pattern, on the upper surface region of the lower insulating film other than the portion thereof right under the magnetic domain controlling film reduced in thickness by ion milling, and on the upper surface region of the magnetic domain controlling film other than the portion thereof right under the magnetoresistive film. An electrode film is formed on the insulating layer, after which the resist pattern is removed. The insulating layer is contiguously deposited on the upper surface region formed in a thin layer of the lower insulating film and on a part of the upper surface region formed in a thin layer of the magnetic domain controlling film.

Magnetoresistive thin-film magnetic head and method of fabrication

In a magnetoresistive head, a domain suppressing layer is formed under each of opposite ends of a magnetoresistive film. The domain suppressing layer is composed of a first ferromagnetic film, an antiferromagnetic film and a second ferromagnetic film which are laminated one over another in this order. Since the spin distribution of the antiferromagnetic film is transmitted to the magnetoresistive film via the second ferromagnetic film, a stable longitudinal bias magnetic field can be achieved, irrespective of the degree of contamination of the surface of the ferromagnetic film.

Thin film magnetoresistive head which includes a domain suppressing

An information recording and erasing method and apparatus of an optical memory medium including a substrate, a guard film, and an intermediate layer portion so disposed between said substrate and said guard film as to include at least a recording material layer having a phase changing with temperature and include at least one good conductor layer, comprising the steps of supplying magnetic flux varying relatively to said good conductor layer to generate eddy currents within said good conductor layer, and heating said recording material layer with heat generated in said good conductor due to the eddy current loss to effect information recording and erasing with respect to said recording material layer.

Optical memory medium and its information recording and erasing method

An optical modulation method and apparatus uses superconductive oxide material for the optical modulation element. The current, magnetic field, temperature or pressure applied to the superconductive oxide material is varied so as to induce a superconduction-normalconduction transition, and the resulting variation in optical characteristics such as the reflectivity, transmissivity or refractive index of the superconductive oxide material modulate the input light. The method and apparatus are fast in operation and simple in structure. The method and apparatus also detect the variation in the current, magnetic field, temperature or pressure as a change in the reflectivity, transmissivity or refractive index of the superconductive oxide material on the basis of a superconduction-normalconduction transition.

Method and apparatus of optical modulation using superconductive oxide

A mail system includes a selector selectively composing character information, image information and/or audio information; a printer printing the composite information as optically readable bit information in a plurality of recording mediums; a first storage device storing specific information for specifying the receivers of said recording media; a second storage device storing the required items of said receivers; a third storage area storing the information related to the required items of said receivers; a selector selecting information corresponding to the required items of said receivers from the information related to the required items of said receivers; a recorder recording the selected information corresponding to the required items of said receivers as optically readable bit information in at least one of said recording media; and a recorder recording the specific information specifying said receivers in at least one of said recording media.

Optically readable mail system with general and receiver specific

A waveguide path type optical pickup is provided for preventing a returning light from returning back to a light source. A filter for selectively allowing either Te polarized light or TM polarized light to pass through the filter is provided in an optical path from a light source to an optical path deflector. An optical part for changing the polarized state of light is provided in an optical path from the optical path changing part to an information recording medium, thereby prevent a reduction in S/N ratio or reproducing signal.

Optical element, optical disc and rotary encoder with the optical element

An optical head including a substrate, an optical waveguide formed on the substrate, a light source formed on a portion of the substrate, a collimator lens for converting light from the light source into parallel light rays, an objective lens for focusing light from the collimator lens onto a recording medium and for converting reflected light from the recording medium into parallel light rays, a beam splitter for dividing light from the objective lens into two parts to send out one of the parts in a predetermined direction, a coupling lens for focusing light from the beam splitter on a position, and a photodetector for detecting light from the coupling lens, is disclosed, in which the collimator lens, the objective lens, the beam splitter, the coupling lens and the photodetector are integrated on the substrate, and the collimator lens or an objective lens supporting part is made flexible to vary the position of the focus of the collimator lens or objective lens by piezo-electric elements.

Intergrated optical head with flexible substrate portion

An optical head is disclosed, in which a plate-shaped optical wave guide comprises an optical system including a collimator lens, a beam splitter and an objective lens; a laser light source for emitting a laser light in the form of a light beam which is to be impinged on an optical recording medium; and electro-acoustic transducers are disposed between the beam splitter and the objective lens, the transducers being adapted to be driven by the outer electrical signal for producing surface acoustic waves in the optical wave guide, thereby establishing a condensation and rarefaction distribution in refractive index in the optical wave guide which distribution influences the direction of transmission and the degree of focusing of the light beam passing therethrough so that regulation of the tracking and the focal length can be effected without any mechanical movements.

Optical head with optical beam control using acoustic wave device

A laser light flux is divided and synthesized so that its light intensity distribution is changed from a Gaussian distribution to a non-Gaussian distribution. When a laser light flux having a Gaussian distribution is irradiated onto a dividing prism, it is divided into a left part and a right part which are refracted right and left inversely from each other. When the right and left parts are incident on a synthesizing prism, they are refracted again and travel to be overlapped with each other on a recording medium. The light intensity distribution on a segment at the apex of the synthesizing prism is weaker at the central part and stronger at the peripheral part. This is because the light fluxes resulting from the division are inverted in their position so that the central part of the Gaussian distribution is separated left and right while the peripheral part with a weaker light intensity is centered.

Optical recording and reproducing device

A film of a crystal - crystal phase transformation type optical recording alloy is formed on an insulating substrate. Information is erased from the alloy film by heating it with an expedient other than a laser beam. Information is read by sensing reflected light of light projected on the alloy film.

Optical information recording device

The present invention employs as a recording medium a metal or alloy which exhibits an intercrystalline transition before and after writing. In the present invention, two light beams of unequal wavelengths are used so as to write information with the light beam of the longer wavelength and to erase information with the light beam of the shorter wavelength. In changing a written content, a wavelength with which the reflection rate of the recording medium increases is used.

Optical information apparatus and method of recording and erasing

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Katsuta, Japan

Hiroaki Koyanagi