Patents by Inventor Yoichi Oba

Yoichi Oba 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: 5222307
    Abstract: A drying method for removing free water resided on electronic parts such as semiconductors, liquid-crystal display devices and printed wiring boards, optical parts such as lenses and prisms, and precision instrument parts such as gears and lead frames having been subjected to advanced cleaning, surface treatments, etc. and to an apparatus therefor. After an object to be dried (A) is placed in a vessel (1), the air present in the inner space of the vessel (1) is replaced with a heated vapor to heat the object to be dried (A) with the heated vapor, and the introduction of the heated vapor is stopped to cool the inner space of the vessel (1) in such a state that the vessel (1) is sealed from the outer air, followed by introduction of a dry gas to the vessel (1). The vessel (1) has a heated vapor introduction pipe (4), a cooling section (8) for cooling the inner space of the vessel (1), a condensate discharge pipe (14) and a dry gas introduction pipe (7).
    Type: Grant
    Filed: July 9, 1991
    Date of Patent: June 29, 1993
    Assignee: Interface Technical Laboratories Co., Ltd.
    Inventors: Yoichi Oba, Shota Oba
  • Patent number: 5066692
    Abstract: An electromagnetic wave shielding circuit and the production method thereof is described, wherein the circuit comprises a base board, an electric circuit formed on the base board, an electrically isolating coating coated over the electric circuit, a layer of coating having copper particles contained therein coated over the electrically isolating coating and hardened by heating, a copper plating layer attached to the surface of the copper particle containing coating for discharging out of the electric circuit an electromagnetic wave current which may be produced in the electric circuit, said copper particle containing coating having contained therein 100% by weight of copper particles and 12%-25% by weight of epoxy resin for a binder.
    Type: Grant
    Filed: June 21, 1990
    Date of Patent: November 19, 1991
    Assignee: Asahi Chemical Research Laboratory Co., Ltd.
    Inventors: Yamahiro Isawa, Isao Morooka, Yoichi Oba
  • Patent number: 4970354
    Abstract: An electromagnetic wave shielding circuit and the production method thereof is described, wherein the circuit comprises a base board, an electric circuit formed on the base board, an electrically isolating coating coated over the electric circuit, a layer of coating having copper particles contained therein coated over the electrically isolating coating and hardened by heating, a copper plating layer attached to the surface of the copper particle containing coating for discharging out of the electric circuit an electromagnetic wave current which may be produced in the electric circuit, said copper particle containing coating having contained therein 100% by weight of copper particles and 12%-25% by weight of epoxy resin for a binder.
    Type: Grant
    Filed: February 21, 1989
    Date of Patent: November 13, 1990
    Assignee: Asahi Chemical Research Laboratory Co., Ltd.
    Inventors: Yamahiro Iwasa, Isao Morooka, Yoichi Oba
  • Patent number: 4837050
    Abstract: A method is described for producing electrically conductive circuits on a print base board having a copper lamination attached on one side face thereof, and more particularly relates to such method for producing the circuits of excellent electrical conductivity by effectively utilizing a newly developed electrically conductive copper paste which is specifically adapted to metal plating, wherein at least two-layer circuits are formed on one side of the base board, of which a first-layer circuit having a plurality of electrodes and a second-layer circuit having a plurality of ring-shaped electrodes formed in connection with the electrodes of the first-layer circuits, each electrode of the second-layer circuit being defined by outer and inner circumferences with a central opening defined by the inner circumference, such that the metal plating applied to the electrodes of the first- and second-layer circuits with a predetermined thickness of the metal plating layer may provide an electrically conductive path betw
    Type: Grant
    Filed: July 30, 1987
    Date of Patent: June 6, 1989
    Assignee: Asahi Chemical Research Laboratory Co., Ltd.
    Inventors: Yamahiro Iwasa, Yoichi Oba, Isao Morooka
  • Patent number: 4684054
    Abstract: An automatic soldering apparatus and method thereof is described, wherein a flux is heated up to a predetermined temperature, and is then contacted to a face of a printed base board to thereby coat the base board and to simultaneously heat the latter with the heated flux and then the heated base board is contacted to a melted solder, and wherein provided in combination are apparatus for transporting the base board, apparatus for coating the base board with the heated flux, the flux coating apparatus including a tank in which the flux is stored, heating elements for heating the flux up to a predetermined temperature such that the heated flux is coated on the face of the base board, the heated flux simultaneously heating the base board when the latter is transported to the flux storing tank, and apparatus for soldering the flux coated and heated base board, the soldering apparatus including a tank in which a melted solder is stored which is contacted to the base board when the latter is transported to the tank,
    Type: Grant
    Filed: March 12, 1986
    Date of Patent: August 4, 1987
    Assignee: Asahi Chemical Research Laboratory Co., Ltd.
    Inventors: Yamahiro Iwasa, Atsushi Kabe, Yoichi Oba
  • Patent number: 4420444
    Abstract: A phosphor powder layer is formed by a process comprising a step of mixing a phosphor powder with a polymer emulsion and drying the mixture to give the phosphor powder coated with the polymer and a step of subjecting the phosphor powder coated with the polymer to heating and pressing. The resulting powder layer is suitable as a scintillator used in a radiation detector, particularly in a radiation detector used in X-ray CT.
    Type: Grant
    Filed: December 8, 1981
    Date of Patent: December 13, 1983
    Assignees: Hitachi, Ltd., Hitachi Medical Corporation
    Inventors: Hiromichi Yamada, Atsushi Suzuki, Yoichi Oba, Yoko Uchida, Hideki Kohno, Tadashi Fukino, Minoru Yoshida
  • Patent number: 4229312
    Abstract: A method of manufacturing a paint composite for magnetic films wherein a mixture consisting of a magnetic powder, a polymer such as polyvinylbutyral, and a solvent is ground under a shear stress of 10-400 kg/cm.sup.2, and the ground mixture has a solvent, an epoxy resin and a phenol resin added thereto and is further ground. When a magnetic disk is produced using a paint which has been obtained by executing the first grinding under a shear stress of 10-400 kg/cm.sup.2 with a kneader or the like, it is endowed with excellent electric characteristics and surface flatness.
    Type: Grant
    Filed: August 13, 1979
    Date of Patent: October 21, 1980
    Assignee: Hitachi, Ltd.
    Inventors: Waichi Nagashiro, Hajime Fukke, Yoshiki Kato, Teruo Tsunoda, Teruaki Kobayashi, Yoichi Oba, Katsuyoshi Chiba, Munehisa Mitsuya, Heigo Ishihara, Mitsushi Endo
  • Patent number: 4219587
    Abstract: Pigment-coated phosphors which may be used in the production of a cathode-ray tube of a high contrast for a color television receiver can be produced by adding a pigment and an anionic polymer emulsion to an aqueous suspension of a phosphor and then making the system neutral or weakly acidic or adding a cationic polymer emulsion or carrying out both of these steps so that the phosphor and the pigment may be coated with the polymer.
    Type: Grant
    Filed: December 19, 1977
    Date of Patent: August 26, 1980
    Assignees: Hitachi, Ltd., Kasei Optonix, Ltd.
    Inventors: Yoichi Oba, Tsuyoshi Kano, Masaaki Hayashi, Hiroshi Takada, Katuzo Kanda, Shusaku Eguchi
  • Patent number: 4206250
    Abstract: A pigment-coated phosphor having good finish sieve passability and capable of forming a fluorescent film with excellent properties can be produced from a process characterized by:(1) the first step of adding to a water suspension of a phosphor and a pigment an anionic polymer emulsion which has a minimum film forming temperature of less than 30.degree. C.;(2) the second step of adding a cationic polymer emulsion which has a minimum film forming temperature of 30.degree. C. or lower;(3) the thrid step of adding an anionic polymer emulsion which has a minimum film forming temperature of 30.degree. C. or higher; and(4) the fourth step of making the mixture system neutral or weakly acidic.
    Type: Grant
    Filed: October 26, 1978
    Date of Patent: June 3, 1980
    Assignees: Hitachi, Ltd., Kasei Optonix, Ltd.
    Inventors: Yoichi Oba, Katuzo Kanda, Shusaku Eguchi, Kazuhito Iwasaki
  • Patent number: 4086090
    Abstract: The present invention affords a process for forming a pattern having a surface area substantially equal to or smaller than area of apertures of shadow-mask through which beams pass on a photoresist film, which contains an acrylamidediacetoneacrylamide copolymer and a water-soluble aromatic bisazide compound, by exposing said photoresist film to light through a mask having the pattern and then developing the film.The use of said photoresist film for the preparation of a phosphor screen of a color picture tube of a black matrix or black stripe type does not require a special technique such as post-etching of a shadow mask and makes it possible to form a three primary color phosphor pattern having a surface area substantially equal to or smaller than the area of apertures of the shadow mask through which lightbeams pass, without mutual "bridging" between phosphor dots. Thus, an excellent phosphor screen of a color picture tube of a black matrix or black stripe type can be prepared.
    Type: Grant
    Filed: September 22, 1975
    Date of Patent: April 25, 1978
    Assignee: Hitachi, Ltd.
    Inventors: Takahiro Kohashi, Motoo Akagi, Yoichi Oba, Saburo Nonogaki, Makoto Tanaka, Tadao Kaneko, Yoshifumi Tomita
  • Patent number: 4040083
    Abstract: Disclosed is a semiconductor device including a Si body, and SiO.sub.2 layer disposed on the surface of the body, an aluminum oxide layer having a thickness of about 50 A on the SiO.sub.2 layer, which is formed by applying a solution including an aluminum chelate compound onto the SiO.sub.2 layer and heating the solution at a temperature of 300.degree. C. for 30 minutes, and a polymer resin layer of polyimide disposed on the aluminum oxide layer. In this device, the adhesive-strength between the SiO.sub.2 layer and the polyimide layer is remarkably increased when compared with a semiconductor device wherein the polyimide layer is directly disposed on the SiO.sub.2 layer.
    Type: Grant
    Filed: November 22, 1974
    Date of Patent: August 2, 1977
    Assignee: Hitachi, Ltd.
    Inventors: Atsushi Saiki, Seiki Harada, Yoichi Oba
  • Patent number: 4001870
    Abstract: An insulating film provided on the surface of a semiconductor device having a protective film of silicon dioxide is composed of a double layer. The double layer consists of a thin film which is disposed on at least a part of the protective film of silicon dioxide and which is made of an organic compound containing either an amino group as well as an alkoxysilane group or an epoxy group as well as an alkoxysilane group, and a film which is disposed so as to cover the thin film of an organic compound and which is made of a heat-resisting polymer resin.The heat-resisting polymer is the reaction product of 4,4'-diamino-diphenylether, 4,4'-diamino-diphenyl ether-3-carbonyl amide, and pyromellitic acid dianhydride.
    Type: Grant
    Filed: November 30, 1973
    Date of Patent: January 4, 1977
    Assignee: Hitachi, Ltd.
    Inventors: Atsushi Saiki, Kikuji Sato, Seiki Harada, Terue Tsunoda, Yoichi Oba