Patents by Inventor Iwao Matsuyama
Iwao Matsuyama 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: 5856281Abstract: Gas contaminants generated from the grease of bearings operating in a magnetic disk device adhere to the magnetic head and causing stiction and magnetic head crash. Such bearings are typically spindle bearings and pivot bearings. In operation, heat is generated that causes the bearing grease to generate the gases. By heat treating the grease, slow evaporating substances of hydrocarbon compounds with carbons of C9 to C13 in the grease are reduced to not more than 0.001 wt. % of the grease. The grease can then be used to lubricate the bearings. The heat treatment is performed at a temperature of 60.degree. to 100.degree. C. at a pressure of 10.sup.-3 to 10.sup.-8 torr. The assembled, lubricated bearings can be heat treated separately from the magnetic disk device or the heat treatment can take place after the bearings have been assembled in the magnetic disk device.Type: GrantFiled: December 18, 1996Date of Patent: January 5, 1999Assignee: Hitachi, Ltd.Inventors: Masaki Otsuka, Iwao Matsuyama, Mitsuhiko Oguchi, Kazuhisa Murakami, Nobuyuki Ishii, Masayuki Katsumoto, Tsuneyuki Hasegawa, Satomi Yamaguchi
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Patent number: 5180616Abstract: A method for manufacturing a magnetic paint by mixing a resin composition powder as a dispersing binder for a magnetic powder with the magnetic powder, or together with a filler, and grinding the mixture under a high shear stress is disclosed. A magnetic recording medium such as a magnetic disk, etc., prepared by using the magnetic paint, can have a magnetic coating film having a substantially uniform film thickness of not more than 0.9 .mu.m and a surface roughness of not more than 0.05 .mu.m Ra before surface finishing.Type: GrantFiled: January 3, 1989Date of Patent: January 19, 1993Assignee: Hitachi, Ltd.Inventors: Hajime Fukke, Motoo Akagi, Iwao Matsuyama, Masayuki Katsumoto, Hitoshi Inoue, Naoki Kodama, Yasutaro Uesaka
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Patent number: 5180608Abstract: A coating type, magnetic disk is produced by applying a magnetic paint containing magnetic powders in a dispersed state to a non-magnetic substrate, thereby forming a magnetic recording film thereon, and applying surface waves to the magnetic recording film in an undried state. By applying the surface waves to the magnetic recording film, dispersibility and orientation of the magnetic powders are improved and a longitudinally oriented, coating type magnetic disk with distinguished electromagnetic properties, such as a high S/N ratio, etc. can be obtained.Type: GrantFiled: October 24, 1990Date of Patent: January 19, 1993Assignee: Hitachi, Ltd.Inventors: Katsuyoshi Chiba, Masayuki Katsumoto, Yasutaro Uesaka, Hajime Fukke, Heigo Ishihara, Iwao Matsuyama, Naoki Kodama, Hitoshi Inoue, Yoshiharu Terada
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Patent number: 5034243Abstract: A method for magnetic orientation of a magnetic recording medium using Meissner effect of a superconductor and a system therefor and a magnetic recording medium produced thereby. The magnetic particles of plate hexagonal barium ferrite in the magnetic coating are allowed to orient in the longitudinal direction thereof so that a magnetic recording medium having a magnetic orientation in such direction with the magnetic particles can be obtained.Type: GrantFiled: November 1, 1989Date of Patent: July 23, 1991Assignee: Hitachi, Ltd.Inventors: Katsuyoshi Chiba, Masayuki Katsumoto, Yasutaro Uesaka, Heigo Ishihara, Naoki Kodama, Hajime Fukke, Iwao Matsuyama, Tsuneo Suganuma
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Patent number: 5028496Abstract: The present invention proposes a ratio of an applied field H.sub.s to a coercivity H.sub.c as a parameter which gives an influence to the write/read characteristics of a magnetic coated recording medium, especially, a reproduction output E.sub.o at a low recording density and a recording density D.sub.50 which provides an output of the half of E.sub.o. By selecting the ratio H.sub.s /H.sub.c to be not larger than 2.1, a magnetic coated recording medium having large values of E.sub.o and D.sub.50 or suited to a high density magnetic recording can be provided with good reproducibility.Type: GrantFiled: October 28, 1988Date of Patent: July 2, 1991Assignee: Hitachi, Ltd.Inventors: Yasutaro Uesaka, Hajime Fukke, Katsuyoshi Chiba, Iwao Matsuyama
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Patent number: 4426216Abstract: Optical glass is produced by heating a porous gel to a high temperature to partly sinter it, heating it in a chlorine-containing atmosphere to subject it to hydroxyl group removal treatment, and then further heating it to sinter it. The optical glass produced by this process does not rise in bubbles even when heated.Type: GrantFiled: January 6, 1982Date of Patent: January 17, 1984Assignee: Hitachi, Ltd.Inventors: Shin Satoh, Kenzo Susa, Iwao Matsuyama, Tsuneo Suganuma
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Patent number: 4324576Abstract: A method for producing optical glass, which comprises charging a mixed solution capable of forming a high-silica-content gel by hydrolysis reaction into a vessel, the inner wall face of which is composed of a material unwettable to the mixed solution, such as a fluorocarbon resin or silicone resin, causing gelation of the mixed solution in the vessel, drying the obtained gel, and heating and sintering the obtained dry gel. When electrodes are placed in the mixed solution at the gelation step and an electric voltage is applied, the time required for formation of the gel is shortened. Furthermore, at the gel-drying step, if the amount of materials evaporated from the gel is detected or the weight of the gel is measured, the detected amount of the evaporated materials or the change of the weight of the gel is fed back to a factor regulating the drying speed, such as the drying temperature to control the drying speed to an appropriate level.Type: GrantFiled: November 21, 1980Date of Patent: April 13, 1982Assignee: Hitachi, Ltd.Inventors: Iwao Matsuyama, Kenzo Susa, Shin Satoh, Tsuneo Suganuma
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Patent number: 4323381Abstract: A process for producing a mother rod useful for the production of an optical fiber which comprises hydrolyzing a silicon alkoxide to prepare a gel of a desired shape, and drying and sintering the gel to produce a block made of a silica glass. The process has the advantages that it is well adapted for mass-production, that a glass made of a B.sub.2 O.sub.3 --SiO.sub.2 system may be produced thereby and that a glass block of arbitrary shape may be readily produced.Type: GrantFiled: July 17, 1980Date of Patent: April 6, 1982Assignee: Hitachi, Ltd.Inventors: Iwao Matsuyama, Kenzo Susa, Tsuneo Suganuma, Shin Satoh, Toshio Katsuyama, Hidehito Obayashi
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Patent number: 4317668Abstract: A method for producing silica glass wherein a dry silica gel subjected to a water desorption treatment and a carbon removal treatment is heated and has its temperature raised in an atmosphere containing chlorine, to perform a hydroxyl group removal treatment, the resultant silica gel is thereafter heated to a temperature of approximately 1,000.degree. C.-1,100.degree. C. in an atmosphere containing at least 1% of oxygen, to perform a chlorine removal treatment, and the resultant silica gel is further heated to a temperature of 1,050.degree. C.-1,300.degree. C. in He or in vacuum, to perform a sintering treatment. The silica glass thus produced does not form bubbles even when heated to high temperatures of or above 1,300.degree. C. Therefore, it is easily worked and it is free from the lowering of transparency attributed to the bubble formation.Type: GrantFiled: January 21, 1981Date of Patent: March 2, 1982Assignee: Hitachi, Ltd.Inventors: Kenzo Susa, Iwao Matsuyama, Shin Satoh, Tsuneo Suganuma
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Patent number: 4259101Abstract: A method for producing an optical fiber preform comprising the steps of blowing, through at least one nozzle, gaseous material producing glass material soot by a CVD reaction to permit the glass material soot to be deposited on a target to produce a soot rod which grows in size, and heating and rendering transparent the soot rod produced in the first step, wherein a pipe is arranged substantially concentrically with the glass material soot so as to permit gas to flow through a clearance between the deposited glass material soot and the inner wall surface of the pipe in a direction in which the soot rod grows in size. The method makes it possible to prevent the outer peripheral portion of the soot rod from becoming porous and to satisfactorily control the diameter of the soot rod.Type: GrantFiled: March 2, 1979Date of Patent: March 31, 1981Assignee: Hitachi, Ltd.Inventors: Yasuo Tsukuda, Katsuyuki Imoto, Kenzo Susa, Iwao Matsuyama, Tsuneo Suganuma
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Patent number: 4119886Abstract: A pulse generator comprising an induction element, and a nonlinear condenser whose dielectric material portion is made of ferroelectric ceramics represented by a general formula of (Pb.sub.1-x-y, Ba.sub.x, Sr.sub.y)(Ti.sub.z, Zr.sub.1-z)O.sub.3.Type: GrantFiled: January 24, 1977Date of Patent: October 10, 1978Assignee: Hitachi, Ltd.Inventors: Shigeru Jyomura, Iwao Matsuyama, Katsuki Miyauchi, Tsune Miyashita, Gyozo Toda
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Patent number: 4019915Abstract: There is provided a method of producing a ceramic represented by the general formula of ABO.sub.3, wherein A includes Pb and at least one element selected from the group consisting of Ba and Sr and B is either of Zr or both of Zr and Ti, by hot-pressing a complex oxide obtained by calcining the mixture of the oxides of A and B characterized by that a solid solution of the oxides of Ba and/or Sr and the oxide of the element constituting B, such as BaTiO.sub.3, SrZrO.sub.3 or (Ba, Sr)ZrO.sub.3, is used as the starting oxides of Ba and/or Sr, and that the starting material contains PbO in an amount of 3 - 20 mol% in excess of that calculated for the objective composition of the final product. Ceramics produced by the method of the present invention have ferroelectric properties and are optically transparent.Type: GrantFiled: October 21, 1974Date of Patent: April 26, 1977Assignee: Hitachi, Ltd.Inventors: Katsuki Miyauchi, Iwao Matsuyama, Gyozo Toda