Patents by Inventor Hitoshi Oka
Hitoshi Oka 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: 6090306Abstract: Provided is a piezoelectric ceramic which achieves a high density, good temperature characteristics and a high Curie temperature, which can fully prevent (a) a decrease in Qmax (Qmax refers to a tan.theta.max when the maximum value of phase angles of third harmonic is a .theta.max), (b) a decrease in q (dynamic range of resonance frequency), (c) an increase in a fundamental wave and (d) the occurrence of a spurious mode in the vicinity of third harmonic, caused by downsizing, and which can materialize a small-sized high-performance piezoelectric element, the piezoelectric ceramic having a composition of the general formula,(Pb.sub.a-k-y-z Sr.sub.x Ln.sub.y Bi.sub.z)(Ti.sub.1-b-c Mn.sub.b Me.sub.c)O.sub.3wherein Ln is at least one element selected from the group consisting of La, Ce and Pr, Me is at least one element selected from the group consisting of Nb, Sb and Ta, and x, y, z, a, b and c represent molar ratios, the composition satisfying 0.ltoreq.x.ltoreq.0.2, 0<y.ltoreq.0.1, 0.001.ltoreq.z.ltoreq.0.Type: GrantFiled: February 11, 1999Date of Patent: July 18, 2000Assignee: TDK CorporationInventors: Taeko Tsubokura, Hitoshi Oka, Kazuo Miyabe, Masayoshi Inoue
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Patent number: 5979475Abstract: A highly clean fluid treatment system having a small system volume is provided by using a Bernoulli holder to accomplish stable holding of a specimen in a simple configuration. A holder having a specimen hold face formed almost the same as a specimen or having a Bernoulli effect producing region and a region surrounding the Bernoulli region made of a specific combination of materials is used and fluid supply sources are connected to the holder for supplying one or more fluids containing a treatment agent of a specimen. Since a force for inhibiting a position shift occurs on the end face of the specimen 10, stable specimen holding is enabled. The space between the specimen and the holder where treatment is executed is narrow and fluid always flows from the treatment space to the outside. Therefore, the fluid treatment system of a small volume producing high treatment efficiency and minimizing the chances of recontamination of the specimen can be provided.Type: GrantFiled: April 28, 1995Date of Patent: November 9, 1999Assignee: Hitachi, Ltd.Inventors: Takao Satoh, Haruo Itoh, Hitoshi Oka, Yoichi Takahara, Akio Saito
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Patent number: 5633175Abstract: A liquid crystal display device is produced by effecting in the course of its production steps a resist-peeling method including the steps of (a) changing the quality of a resist layer on a substrate, (b) contacting the changed resist with a liquid containing 2-amino-1-ethanol, and (c) removing the liquid containing the thus peeled resist from the surface of the etched resist, and optionally, (d) regenerating a liquid containing 2-amino-1-ethanol by distillation from the liquid used in step (c) and reusing the regenerated liquid in step (b).Type: GrantFiled: January 17, 1995Date of Patent: May 27, 1997Assignee: Hitachi, Ltd.Inventors: Hiroshi Kikuchi, Yasushi Sano, Satoru Todoroki, Hitoshi Oka, Toshiyuki Koshita, Masato Kikuchi, Mitsuo Nakatani, Michio Tsukii
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Patent number: 5409544Abstract: A method of controlling the adhesion of fine particles to an object in a solution characterized in that the adhesion of fine particles in the solution is prevented or reduced by adding into the solution a material, which is capable of controlling the zeta potential (surface potential) of the fine particles, in the amount of 10.sup.-7 to 25% by volume.Type: GrantFiled: September 8, 1993Date of Patent: April 25, 1995Assignee: Hitachi, Ltd.Inventors: Katsuhiro Ota, Akio Saito, Yoichi Takahara, Hitoshi Oka
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Patent number: 5399202Abstract: A resist is peeled without leaving a residue after peeling, by bringing a resist-peeling liquid comprising a primary aliphatic amine of 2-6 carbon atoms into contact with the surface of an etched novolak positive photoresist, and removing the resist-peeling liquid containing the thus peeled resist from the surface of the etched resist. The used resist-peeling liquid can easily be recovered and regenerated.Type: GrantFiled: December 8, 1992Date of Patent: March 21, 1995Assignee: Hitachi, Ltd.Inventors: Hiroshi Kikuchi, Yasushi Sano, Satoru Todoroki, Hitoshi Oka, Toshiyuki Koshita, Masato Kikuchi, Mitsuo Nakatani, Michio Tsukii
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Patent number: 5388328Abstract: A process for the fabrication of an interconnected multilayer board involves the steps of forming a metallic under-conductive layer on a base substrate, forming a windowed resist layer on the metallic under-conductive layer, filling windows of the resist layer with a conductor by plating thereby forming a conductor layer, forming another windowed resist layer on the conductor layer and filling windows of this resist layer with a conductor by plating, thereby forming a via-hole layer and to provide a two-level structure of the conductor layer and the via-hole layer. Thereafter, the resist layers and portions of the metallic under-conductor layer other than those in contact with a lower face of the conductor constituting the conductor layer are dissolved to form a two-level skeleton structure of conductor lines and spaces within the skeleton structure are filled with a varnish in a solventless form and the varnish is cured.Type: GrantFiled: January 28, 1994Date of Patent: February 14, 1995Assignee: Hitachi, Ltd.Inventors: Hitoshi Yokono, Hideo Arima, Takashi Inoue, Naoya Kitamura, Haruhiko Matsuyama, Hitoshi Oka, Fumio Kataoka, Fusaji Shoji, Hideyasu Murooka, Masayuki Kyooi
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Patent number: 5387493Abstract: A resin composition for forming conductor patterns comprising a photo curable resin, a photopolymerization initiator, a thermosetting resin, agent for the thermosetting resin, photosensitive semiconductor particles, and if necessary a polyfunctional unsaturated compound is suitable for forming very fine conductor patterns in a build-up method.Type: GrantFiled: October 18, 1990Date of Patent: February 7, 1995Assignee: Hitachi, Ltd.Inventors: Shinichiro Imabayashi, Hitoshi Oka, Isamu Tanaka, Hiroshi Kikuchi, Makio Watanabe
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Patent number: 5348590Abstract: A preflux for a printed circuit board is provided, and the preflux has an excellent heat resistance adapted to a method of surface mounting electronic parts on the printed circuit board, and it is highly operable and reliable. The preflux is comprised mainly of a 2-alkylbenzimidazole derivative having the general formula of ##STR1## wherein R.sup.1 and R.sup.2 may be identical with or different from each other and are hydrogen atom, a lower alkyl group or a halogen atom, and R.sup.3 is an alkyl group of three or more carbon atoms, and contains a chelating agent reacting with copper ions added thereto. Addition of a proper amount of the chelating agent to the preflux makes it easy to form a highly heat-resistant film of the preflux only on copper or copper alloy patterns without masking the printed contacts and joint land.Type: GrantFiled: August 31, 1993Date of Patent: September 20, 1994Assignees: Hitachi, Ltd., Hitachi Computer ElectronicsInventors: Seizi Shigemura, Hitoshi Oka, Motokazu Shindo
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Patent number: 5300735Abstract: Described herein are interconnected mutilayer boards and their fabrication processes. Multilayer conductor lines of a skeleton structure are formed by conducting multilayer metallization while including all resist layers and metallic under-conductive layers and then removing the resist layers and metallic under-conductive layers at once. Spaces between the multilayer conductor lines of the skeleton structure are then filled with a solventless varnish so that insulating layers are formed. Modules making use of such interconnected multilayer boards and computers having such modules are also described.Type: GrantFiled: March 22, 1993Date of Patent: April 5, 1994Assignee: Hitachi, Ltd.Inventors: Hitoshi Yokono, Hideo Arima, Takashi Inoue, Naoya Kitamura, Haruhiko Matsuyama, Hitoshi Oka, Fumio Kataoka, Fusaji Shoji, Hideyasu Murooka, Masayuki Kyooi
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Patent number: 5268255Abstract: A printed circuit board has a resist layer made from a photo-setting resist composition containing:(A) a polyfunctional unsaturated compound which is solid at room temperature,(B) a polyfunctional unsaturated compound which is liquid at room temperature,(C) a photopolymerization initiator,(D) an epoxy resin,(E) at least one member selected from the group consisting of:(i) a curing agent for the epoxy resin and either melamine or the derivative thereof, and(ii) a compound having a 2,4-diamino-s-triazine ring and an imidazole ring in the molecule.Type: GrantFiled: September 30, 1991Date of Patent: December 7, 1993Assignee: Hitachi, Ltd.Inventors: Hiroshi Kikuchi, Makio Watanabe, Shinichiro Imabayashi, Reiko Yano, Isamu Tanaka, Hitoshi Oka, Yukihiro Taniguchi, Shigeru Fujita
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Patent number: 5256247Abstract: A resistor material having at least chromium, silicon and oxygen, Cr.SiO.sub.2, contained in electronic integrated circuits, particularly in the case of an aluminum layer being on the material, is etched with a liquid etchant composition containing 1.92 to 2.64 mol/l of hydrochloric acid, 0.26 to 0.77 mol/l of phosphoric acid, 5 to 10 mol/l hydrofluoric acid and 3.2 to 5.4 mol/l of ammonium fluoride.Type: GrantFiled: November 21, 1991Date of Patent: October 26, 1993Assignee: Hitachi, Ltd.Inventors: Takayoshi Watanabe, Takashi Inoue, Hitoshi Oka, Minoru Tanaka
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Patent number: 5091283Abstract: A photo curable diallyl phthalate resin composition characterized by containing 0.1 to 10 parts by weight of an agent for preventing back side undesirable curing and 20 to 100 parts by weight of a filler per 100 parts by weight of a diallyl phthalate prepolymer is particularly suitable for a partly additive process for forming a solder resist effective for preventing back side undesirable curing by ultraviolet light and having resistance to release of substances from the solder resist for deteriorating properties of plated copper film as well as for giving good mechanical properties.Type: GrantFiled: March 27, 1990Date of Patent: February 25, 1992Assignee: Hitachi, Ltd.Inventors: Isamu Tanaka, Hitoshi Oka, Makio Watanabe, Hiroshi Kikuchi, Shinichiro Imabayashi, Yukihiro Taniguti
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Patent number: 4828451Abstract: An industrial robot provided with at least six joints and adapted to have at least six degrees of freedom, wherein rotational joints rotatable around axes extending lengthwise of the arm and bending joints swingable around perpendicular axes extending perpendicularly to the lengthwise direction of the arm, thereby enabling the position and attitude control for a wrist at the arm and the obstacle avoiding control to change height of an elbow portion at the arm so as to avoid the obstacle.Type: GrantFiled: August 5, 1987Date of Patent: May 9, 1989Assignee: Daikin Industries, Ltd.Inventors: Tadafumi Mikoshi, Hitoshi Oka, Akira Fukuda
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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: 4563217Abstract: An electroless copper plating solution comprising cupric ions, complexing agents, a reducing agent, a pH adjustor, a polyoxyethylene series surface active agent, these being conventionally used, and (i) an inorganic compound containing at least Si or Ge, or (ii) a cationic surface active agent, or (iii) an inorganic compound containing at least Si, Ge or V and a cationic surface active agent, can give plated films with excellent mechanical properties even if operated for a long period of time with excellent stability of the plating solution.Type: GrantFiled: June 22, 1984Date of Patent: January 7, 1986Assignee: Hitachi, Ltd.Inventors: Hiroshi Kikuchi, Akira Tomizawa, Hitoshi Oka
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Patent number: 4555532Abstract: An epoxy resin composition containing as a latent hardener a diaminotriazine-modified imidazole compound and dicyandiamide is improved in the usable life of an solder resist ink composition and can give a solder resist also excellent in resistance to an electroless plating bath.Type: GrantFiled: October 10, 1984Date of Patent: November 26, 1985Assignee: Hitachi, Ltd.Inventors: Isamu Tanaka, Hiroshi Kikuchi, Akira Tomizawa, Hitoshi Oka
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Patent number: 4460718Abstract: An epoxy resin composition comprising an epoxide compound, a guanidine compound, a filler, a thixotropic agent and an organic solvent and having a thixotropy index of 5 to 40 and a viscosity of 800 to 10,000 poises (at 20.degree. C.) is suitable for forming a resist film which is used in electroless metal plating with excellent heat resistance, solder resistance and corrosion resistance, and the like.Type: GrantFiled: February 24, 1983Date of Patent: July 17, 1984Assignee: Hitachi, Ltd.Inventors: Isamu Tanaka, Hitoshi Oka, Akira Tomizawa, Hiroshi Kikuchi
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Patent number: 4347304Abstract: Metallic images of uniform quality can be formed on substrates having through-holes by a process using a positive type resist characterized by using as a coating solution for the substrate a solution of a photosensitive material of (a) at least one organic compound having at least one linkage of --M--M--M ).sub.n (M=Si, Ge or Sn; n=0, 1 or more) in the molecule or (b) a mixture of at least one organic compound (a) mentioned above and at least one photosensitizer, dissolved in a solvent such as a halogenated hydrocarbon, an aromatic hydrocarbon, a heterocyclic compound, or a mixture thereof, followed by irradiation with an actinic light through a photomask and electroless plating.Type: GrantFiled: June 24, 1981Date of Patent: August 31, 1982Assignee: Hitachi, Ltd.Inventors: Hideki Sakurai, Mitsuo Nakatani, Hitoshi Oka, Hitoshi Yokono, Tokio Isogai
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Patent number: 4324629Abstract: During recyclic use of a chemical copper plating solution, counter anions to copper ions, anions formed by oxidation of a reducing agent, and carbon dioxide by absorption of carbon dioxide from air, which all have an inhibiting effect upon the plating, and also sodium ions having no inhibiting effect are accumulated in the plating solution.These accumulated ions can be removed by electrodialysis. Particularly, regeneration can be satisfactorily regenerated by adjusting the pH of used chemical plating solution to 2-11 before the electrodialysis, and using a selectively monovalent anion permeable membrane as an anion exchange membrane at the electrodialysis.Type: GrantFiled: June 17, 1980Date of Patent: April 13, 1982Assignee: Hitachi, Ltd.Inventors: Hitoshi Oka, Hiroshi Kikuchi, Hitoshi Yokono, Haruo Suzuki, Toyofusa Yoshimura, Akira Matsuo, Osamu Miyazawa, Isamu Tanaka, Tokio Isogai
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Patent number: 4310563Abstract: The pH of a chemical copper plating solution is exactly measured for a prolonged time by utilizing a copper oxide prepared by etching metallic copper in an 0.1-1 N inorganic acid then oxidizing the etched metallic copper in an aqueous 0.1-1 N alkali metal hydroxide solution as a main electrode for pH measurement or reducing agent concentration measurement in terms of pH.A combination of the pH measurement with well known procedures for measuring concentrations of cupric ions and a complexing agent exactly measures the pH and the concentrations of a reducing agent, cupric ions and a complexing agent for a continuation of longer time than the conventional procedures.Type: GrantFiled: October 15, 1980Date of Patent: January 12, 1982Assignee: Hitachi, Ltd.Inventors: Hitoshi Oka, Kenji Nakamura, Hitoshi Yokono, Tokio Isogai, Akira Matsuo, Osamu Miyazawa, Isamu Tanaka