Patents by Inventor Yoshinori Miyamura

Yoshinori Miyamura has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5372843
    Abstract: A magnetic recording medium comprising a substrate, a diffusion element layer formed on the substrate from a material to be diffused into a magnetic film by heating, a diffusion barrier formed in a desired pattern on the diffusion barrier, and the magnetic film formed on the pattern of the diffusion barrier and on other area than the area of the pattern, the magnetic film having a portion of reduced saturation magnetization in repetition in a direction perpendicular to a recording direction. The magnetic recording medium can be obtained by forming a diffusion element layer, a diffusion barrier in a desired pattern, and a magnetic film, in a stacked form on a substrate, followed by heating.
    Type: Grant
    Filed: March 10, 1992
    Date of Patent: December 13, 1994
    Assignee: Hitachi, Ltd.
    Inventors: Yoshinori Miyamura, Masaaki Futamoto, Yoshibumi Matsuda
  • Patent number: 5330880
    Abstract: In a process for producing optical disks comprising the steps of subjecting the photoresist layer on a substrate formed of silicon, quartz, glass or a metal to light exposure, developing and etching treatments to obtain a stamper and then duplicating an information pattern for an optical disk from the stamper obtained above to a transparent substrate by using a UV curable resin to prepare a replicated substrate of an optical disk, a large number of stampers can be prepared in a short time by conducting the light exposure either by contacting the mask side surface of a substrate provided with a photomask having an information pattern for an optical disk to the photoresist side surface of said substrate having the photoresist layer or by noncontact projection, and a rapid replication of large quantities of replicated substrates becomes possible by using a large number of stampers thus prepared.
    Type: Grant
    Filed: August 28, 1992
    Date of Patent: July 19, 1994
    Assignee: Hitachi, Ltd.
    Inventors: Shinkichi Horigome, Yoshinori Miyamura, Yumiko Anzai, Keizo Kato, Hiroshi Shiraishi
  • Patent number: 5325244
    Abstract: A magnetic recording data storage system includes a magnetic recording medium having pits formed therein, the pits defining recording tracks on the magnetic recording medium and being arranged in a staggered manner relative to respective center lines of the recording tracks, a magnetic head including an inductive element for recording data on the recording tracks and a magnetoresistive element for reproducing data from the recording tracks, one of (1) a unit for magnetically producing a signal from the pits, and (2) an optical unit for optically producing a signal from the pits, the optical unit including a laser for illuminating the pits, servo means for positioning the head on the recording tracks based on the signal produced from the pits, the servo means including a dual-stage actuator including a rough movement portion and a fine movement portion.
    Type: Grant
    Filed: February 28, 1992
    Date of Patent: June 28, 1994
    Assignee: Hitachi, Ltd.
    Inventors: Hisashi Takano, Kyo Akagi, Mikio Suzuki, Yoshibumi Matsuda, Takeshi Nakao, Yoshinori Miyamura, Fumio Kugiya, Masaaki Futamoto, Hideki Sawaguchi, Nobuyuki Inaba, Takayuki Munemoto, Kenji Mori, Hirotsugu Fukuoka, Tokuho Takagaki
  • Patent number: 5270987
    Abstract: A magnetic field of a polarity corresponding to information to be recorded is applied while a recording spot having a high energy is irradiated to a magneto-optical recording medium to record domains representing the information along a track. The recorded domains are read out by a reproducing spot having a lower energy than the recording spot and a high resolution power along the track.
    Type: Grant
    Filed: April 17, 1990
    Date of Patent: December 14, 1993
    Assignee: Hitachi, Ltd.
    Inventors: Toshimitsu Kaku, Shigeru Nakamura, Masahiko Takahashi, Toshio Niihara, Harukazu Miyamoto, Norio Ohta, Takeshi Nakao, Hirofumi Sukeda, Masahiro Ojima, Takashi Toyooka, Tsuneo Suganuma, Fumiyoshi Kirino, Yoshinori Miyamura
  • Patent number: 5235591
    Abstract: A separation type optical head according to the present invention includes at least a light source portion for emitting collimated beams, a focusing device (a focusing lens) for focusing the collimated beams onto an information recording surface of an optical disc medium, a focal point control mechanism for the position of the spot on the information recording surface, and a photo-detection portion for receiving beams reflected by the information recording surface. The structure is divided into a fixed portion including the light source portion and the photo-detection portion and a movable portion including the focusing device (focusing lens) and the focal point control mechanism. At least the movable portion of the separation type optical head is movably accommodated n a frame (sealing case) for the optical head so as to prevent irregular vibrations of the movable portion due to high speed air flows or turbulence.
    Type: Grant
    Filed: January 15, 1991
    Date of Patent: August 10, 1993
    Assignee: Hitachi, Ltd.
    Inventors: Shigeru Nakamura, Eiichi Seya, Seiichi Mita, Masuo Kasai, Masahiro Ojima, Hiroshi Yasuoka, Motoyasu Terao, Yoshinori Miyamura, Takeshi Nakao, Kiyoshi Matsumoto, Yoshihiro Hamakawa
  • Patent number: 5179546
    Abstract: A magneto-optical disk which has a circular disk form and comprises a substrate provided with information pits and a guide groove, a recording medium layer provided on the substrate, and a protective layer formed of at least one thin film on the medium layer, in which the surface of the protective layer is minutely roughened to have a concave rough pattern and not to substantially protrude beyond a reference level composed of the outermost surface portions of the protective layer. When the magneto-optical disk is subjected to recording by a CSS system using an air floating magnetic head conforming to high-frequency recording in a magnetic field modulation type recording, which is one of methods of overwrite recording on magneto-optical disks, the minute concave rough pattern formed on the surface of the disk substrate prevents such troubles as adhesion of the magnetic head to the surface of the disk and collision between the disk substrate being rotated and the head.
    Type: Grant
    Filed: December 21, 1990
    Date of Patent: January 12, 1993
    Assignees: Hitachi, Ltd., Hitachi Maxwell, Ltd.
    Inventors: Yumiko Anzai, Yoshinori Miyamura, Toshio Niihara, Harukazu Miyamoto, Norio Ohta
  • Patent number: 5093822
    Abstract: A high-density magnetic recording and optical reproducing apparatus for magneto-optically reproducing information magnetically recorded on information tracks on a recording medium, the apparatus comprising two laser beam sources emitting laser beams having different wavelengths respectively, an optical system for directing the laser beams from the two laser beam sources toward and onto the recording medium so as to irradiate the recording medium with laser beam spots partly overlapping each other, two photo detectors detecting the laser beams reflected from the surface of the recording medium, and a differential amplifier detecting the difference between the output signals of the two photo detectors thereby generating the differential signal as a reproduced output.
    Type: Grant
    Filed: June 4, 1990
    Date of Patent: March 3, 1992
    Assignee: Hitachi, Ltd.
    Inventors: Fumio Kugiya, Mikio Suzuki, Kyo Akagi, Takeshi Nakao, Masaaki Futamoto, Yoshinori Miyamura, Hisashi Takano, Yoshibumi Matsuda
  • Patent number: 5020041
    Abstract: A magneto-optical memory apparatus has an optical head for applying a light to a substrate of a recording medium such as a magneto-optical disk having a magneto-optical recording film formed on the substrate and continuously applying a high power laser beam in a record mode, and a floating magnetic head arranged on the opposite side of the recording medium to the side of the optical head and adapted to be kept at a substantially constant distance from the recording medium by an air pressure created between the magnetic head and the recording medium by the movement of the recording medium, for applying, in the record mode, a magnetic field which is polarity-inverted or intensity-modulated according to information to be recorded, to the magneto-optical recording film.
    Type: Grant
    Filed: February 8, 1988
    Date of Patent: May 28, 1991
    Assignee: Hitachi, Ltd.
    Inventors: Takeshi Nakao, Masahiro Ojima, Yoshinori Miyamura, Toyoji Okuwaki, Youichi Kawakubo, Yoshinori Takeuchi, Yuzo Yamaguchi
  • Patent number: 4889757
    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.
    Type: Grant
    Filed: February 19, 1987
    Date of Patent: December 26, 1989
    Assignee: Hitachi, Ltd.
    Inventors: Shinkichi Horigome, Toshio Niihara, Norio Ohta, Yutaka Sugita, Yoshinori Miyamura, Ryoichi Sudo, Hiroaki Miwa, Tetsuo Tajima
  • Patent number: 4407880
    Abstract: A substrate of a recording member comprising a hard base, a first organic substance layer which is formed on the base, and a second organic substance layer which is made of a solvent-soluble organic substance and which is formed on a surface of the first organic substance layer opposite to a surface thereof lying in contact with the base. This substrate can be reused.
    Type: Grant
    Filed: November 7, 1980
    Date of Patent: October 4, 1983
    Assignee: Hitachi, Ltd.
    Inventors: Motoyasu Terao, Shinkichi Horigome, Kazuo Shigematsu, Yoshinori Miyamura, Seiji Yonezawa
  • Patent number: 4357616
    Abstract: A recording medium having at least a first inorganic material layer which overlies a predetermined substrate and which exhibits a light absorptivity for projected light, and a recording layer which overlies the first inorganic material layer and whose principal component is an organic material. The first inorganic material layer contains at least one element selected from the group consisting of In, Bi, Te, Sb, Ge, Sn, Pb, Cr, Nb, Ni, Pd, Fe, Pt, Re, Ta, Th, Ti, Zr and Tl and the content of the element or elements is at least 65 atomic-%.Further, the first inorganic material layer may well be overlaid with a second inorganic material layer which exhibits a light transmissivity higher than that of this first inorganic material layer. Preferable as the material of the second inorganic material layer is an inorganic material which contains at least one element selected from the group consisting of In, Bi, Te, Sb, Pb, Ge and Sn and at least one element selected from the group consisting of S, Se and O.
    Type: Grant
    Filed: March 19, 1980
    Date of Patent: November 2, 1982
    Assignee: Hitachi, Ltd.
    Inventors: Motoyasu Terao, Yoshio Taniguchi, Shinkichi Horigome, Kazuo Shigematsu, Masahiro Ojima, Yoshinori Miyamura, Seiji Yonezawa
  • Patent number: 4348461
    Abstract: A recording member having a predetermined substrate, and a thin film which is formed on the substrate and which is formed with recesses or pits for recording information when irradiated with a working beam, characterized in that said thin film is formed of an inorganic material which contains at least arsenic, selenium and tellurium, and that a distribution of either of said Se and said Te decreases from a part near the surface of said thin film towards a central part thereof, while a distribution of said As increases from a part near the surface towards said central part, is disclosed. This recording member can afford a high signal-to-noise ratio and a long lifetime.
    Type: Grant
    Filed: June 18, 1980
    Date of Patent: September 7, 1982
    Assignee: Hitachi, Ltd.
    Inventors: Motoyasu Terao, Yoshio Taniguchi, Shinkichi Horigome, Masahiro Ojima, Kazuo Shigematsu, Keizo Kato, Yoshinori Miyamura, Seiji Yonezawa