Patents by Inventor Nobuo Nakagawa
Nobuo Nakagawa 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).
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Patent number: 8184397Abstract: A hard-disk drive. The hard-disk drive includes a disk enclosure, a magnetic-recording disk accommodated in the disk enclosure, and a diffusion suppressing film. The diffusion suppressing film divides the space in the disk enclosure into a first space where the magnetic-recording disk is disposed and a second space for retaining a lubricant. The diffusion suppressing film also suppresses diffusion of the lubricant from the second space to the first space.Type: GrantFiled: December 9, 2009Date of Patent: May 22, 2012Assignee: Hitachi Global Storage Technologies, Netherlands B.V.Inventors: Yukio Kato, Junguo Xu, Nobuo Nakagawa
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Publication number: 20110122531Abstract: A hard-disk drive. The hard-disk drive includes a disk enclosure, a magnetic-recording disk accommodated in the disk enclosure, and a diffusion suppressing film. The diffusion suppressing film divides the space in the disk enclosure into a first space where the magnetic-recording disk is disposed and a second space for retaining a lubricant. The diffusion suppressing film also suppresses diffusion of the lubricant from the second space to the first space.Type: ApplicationFiled: December 9, 2009Publication date: May 26, 2011Inventors: Yukio KATO, Junguo Xu, Nobuo Nakagawa
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Publication number: 20060081527Abstract: Embodiments of the invention eliminate, in an elemental analysis made of fine particles trapped using a conventional analytical filter, a hindrance to correct identification of elements of the fine particles as an original object of measurement that would otherwise cause the X-ray analyzer to measure elements of a filter base in addition to those of the fine particles. In one embodiment, an analytical filter includes a filter base and a metallic coating film. The filter base made of a resin has a plurality of filtering holes, each having a hole diameter ranging between about 100 nm and 1000 nm. The metallic coating film is formed on one face of the filter base through ion sputtering of gold (Au). The metallic coating film is so thick that an electron beam from an X-ray analyzer does not penetrate therethrough and the filtering holes are not plugged up. The metallic coating film is at least about 40 nm thick and is preferably about 40 nm to 100 nm thick.Type: ApplicationFiled: October 13, 2005Publication date: April 20, 2006Applicant: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Katsuji Ichikawa, Nobuo Nakagawa, Mitsuhiko Oguchi
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Patent number: 5651867Abstract: A plasma processing apparatus comprising: a vacuum container; an evacuation means for keeping the interior of the vacuum container at a pressure not higher than atmospheric pressure; a substrate support device for supporting a substrate to be subjected to plasma processing; an electrode for generating plasma in cooperation with the substrate support; a voltage supply for applying a voltage to the electrode; a gas introducing system for introducing a gaseous material into a space where the plasma is produced; a surrounding member for enclosing the space above the substrate support, and a drive for relatively moving the surrounding member to space an end of the surrounding member proximate from the substrate from at least one of the substrate support and the substrate supported thereon by a distance which is short enough to suppress plasma leakage during the plasma processing and to position the end of the surrounding member away from said at least one of the substrate support and the substrate thereon for charType: GrantFiled: October 2, 1990Date of Patent: July 29, 1997Assignee: Hitachi, Ltd.Inventors: Yuichi Kokaku, Hiroyuki Kataoka, Makoto Kitoh, Shigehiko Fujimaki, Satoshi Matsunuma, Kenji Furusawa, Nobuo Nakagawa, Katsuo Abe, Masaaki Hayashi
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Patent number: 5494721Abstract: A substrate for a magnetic disc, which comprises a crystallized glass consisting essentially of an amorphous glass continuous phase and crystal particles dispersed in the continuous phase, the substrate having fine projections of the crystal particles on the surface thereof, a method of producing the substrate, the magnetic disc using the substrate, and a method of producing the magnetic disc are provided. The crystallized glass is made from a glass material of a Li.sub.2 O--SiO.sub.2, Li.sub.2 O--Al.sub.2 O.sub.3 --SiO.sub.2, Li.sub.2 O--MgO--Al.sub.2 O.sub.3 --SiO.sub.2, MgO--Al.sub.2 O.sub.3 --SiO.sub.2, Na.sub.2 O--Al.sub.2 O.sub.3 --SiO .sub.2 or BaO--Al.sub.2 O.sub.3 --SiO.sub.2 system, and the crystal particles have one or more compositions selected from Li.sub.2 O--SiO.sub.2, Li.sub.2 O.2SiO.sub.2, Li.sub.2 O.Al.sub.2 O.sub.3.2Si.sub.2, Li.sub.2 O.Al.sub.2 O.sub.3 4SiO.sub.2, SiO.sub.2 and 2MgO--2Al.sub.2 O.sub.3.5SiO.sub.2, and an average particle size of 0.01 to 3.0 .mu.Type: GrantFiled: August 26, 1993Date of Patent: February 27, 1996Assignee: Hitachi, Ltd.Inventors: Nobuo Nakagawa, Hirayoshi Tanei
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Patent number: 5285343Abstract: There is provided a magnetic disk apparatus including at least one magnetic disk having a magnetic layer and a surface protective layer on a substrate; a magnetic head which faces the magnetic disk in a rotating state with a micro gap and is supported by a slider; rotating means for rotating the magnetic disk; and magnetic head positioning means for moving and positioning the magnetic head to a predetermined position on the magnetic disk, wherein a plurality of protrusions each having a flat surface are formed in at least a region on the surface of the magnetic disk where a contact start/stop operation can be executed, an area ratio of the protrusions per 1 mm.sup.2 lies within a range from 0.1 to 80%, a height of the protrusion of the maximum height among the protrusions lies within a range from 5 to 40 nm, and the magnetic layer is formed on the whole surface on the base plate.Type: GrantFiled: October 11, 1990Date of Patent: February 8, 1994Assignee: Hitachi, Ltd.Inventors: Hideaki Tanaka, Kenichi Gomi, Shoichi Sawahata, Maki Kondo, Masaki Ohura, Norikazu Tsumita, Katuo Uda, Yoshiki Kato, Yoshihiko Miyake, Toyoji Okuwaki, Noriaki Okamoto, Nobuo Nakagawa
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Patent number: 5093173Abstract: A substrate for a magnetic disc, which comprises a crystallized glass consisting essentially of an amorphous glass continuous phase and crystal particles dispersed in the continuous phase, the substrate having fine projections of the crystal particles on the surface thereof, a method of producing the substrate, the magnetic disc using the substrate, and a method of producing the magnetic disc are provided. The crystallized glass is made from a glass material of a Li.sub.2 O-SiO.sub.2, Li.sub.2 O-Al.sub.2 O.sub.3 -SiO.sub.2, Li.sub.2 O-MgO-Al.sub.2 O.sub.3 -SiO.sub.2, MgO-Al.sub.2 O.sub.3 -SiO.sub.2, Na.sub.2 O-Al.sub.2 O.sub.3 -SiO.sub.2 or BaO-Al.sub.2 O.sub.3 -SiO.sub.2 system, and the crystal particles have one or more compositions selected from Li.sub.2 O.multidot.SiO.sub.2, Li.sub.2 O.multidot.2SiO.sub.2, Li.sub.2 O.multidot.Al.sub.2 O.sub.3 .multidot.2SiO.sub.2, Li.sub.2 O.multidot.Al.sub.2 O.sub.3 .multidot.4SiO.sub.2, SiO.sub.2 and 2MgO.multidot.2Al.sub.2 O.sub.3 .multidot.5SiO.sub.Type: GrantFiled: January 10, 1990Date of Patent: March 3, 1992Assignee: Hitachi, Ltd.Inventors: Nobuo Nakagawa, Hirayoshi Tanei
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Patent number: 4735853Abstract: Disclosed is a magnetic recording medium in which an underlayer formed below a magnetic medium, in which a signal is written, is composed of a nickel alloy comprising 0.05 to 10 atom % of tungsten and 14 to 30 atom % of phosphorus. In this magnetic recording medium, the temperature for formation of magnetic medium and the temperature for formation of a protective film can be elevated over the levels adopted in the conventional techniques. Therefore, the magnetic characteristics and abrasion resistance can be improved. Furthermore, the magnetic recording medium is excellent in the mechanical strength and corrosion resistance. Accordingly, the reliability of the magnetic medium can be highly improved.Type: GrantFiled: May 15, 1986Date of Patent: April 5, 1988Assignee: Hitachi, Ltd.Inventors: Hiroaki Okudaira, Hitoshi Oka, Masako Fujisawa, Yoshio Gobara, Nobuo Nakagawa
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Patent number: 4444635Abstract: A film forming method by plasma sputtering is provided to attain a composite film on a substrate. A target plate having metal materials in a different pattern is prepared in opposition to the substrate. A plasma is created by a planar magnetron sputtering electrode structure. The plasma is shifted magnetically on the target plate by at least three magnetically coupled magnetic poles to deposit the materials into a film with a uniform thickness and a desired composition on the substrate.Type: GrantFiled: July 21, 1982Date of Patent: April 24, 1984Assignee: Hitachi, Ltd.Inventors: Shigeru Kobayashi, Nobuo Nakagawa, Katsuo Abe, Tsuneaki Kamei, Kazuyuki Fujimoto
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Patent number: 4430387Abstract: A base plate for magnetic recording disc is produced by coating thin metal layers containing no impurities for forming defects by an anodizing treatment on one or both sides of a discoid substrate made of a metal such as aluminum or an aluminum alloy or from a plastic by a dry process, and anodizing the thin metal layers so as to form anodized film from the surfaces of the thin metal layers to a certain depth while the portions contacting to the substrate are retained not anodized.Type: GrantFiled: November 12, 1980Date of Patent: February 7, 1984Assignee: Hitachi, Ltd.Inventors: Nobuo Nakagawa, Yoshiki Kato, Katsuo Abe, Takao Edamura, Takao Nakamura
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Patent number: 4303443Abstract: When an amine compound having at least two polyolefin glycol chains in one molecule is used as a stabilizer, and an alkylene diamine compound, at least one hydrogen atom in the respective amino groups thereof being substituted by CH.sub.2 COOX (wherein X is H or Na) and another hydrogen atom in the respective amino group thereof being substituted by CH.sub.Type: GrantFiled: June 13, 1980Date of Patent: December 1, 1981Assignee: Hitachi, Ltd.Inventors: Osamu Miyazawa, Hitoshi Oka, Isamu Tanaka, Akira Matsuo, Hitoshi Yokono, Nobuo Nakagawa, Tokio Isogai