Patents by Inventor Isao Watanabe

Isao Watanabe 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: 6136475
    Abstract: A lithium secondary battery includes a cathode which can be dischargeably charged with lithium ions, an anode made of lithium metal, a lithium alloy or any other anode material which can be releasably doped with lithium ions, an electrolyte which allows migration of lithium ions between both electrodes, and an endothermic substance which undergoes an endothermic reaction upon a temperature rise of the battery for preventing excessive heat generation. Typically, the endothermic substance is a metal carbonate such as magnesium carbonate, cobalt (II) carbonate, silver carbonate, cadmium carbonate or sodium hydrogencarbonate.
    Type: Grant
    Filed: July 13, 1998
    Date of Patent: October 24, 2000
    Assignee: Fujitsu Limited
    Inventors: Masami Tsutsumi, Hiroshi Horiuchi, Tamotsu Yamamoto, Isao Watanabe, Tsutomu Miyashita
  • Patent number: 6104047
    Abstract: The present invention relates to an avalanche photodiode having a simple structure, high reliability, and a high speed response on the order of Gbps. This photodiode is formed by depositing laminated layers on a semiconductor substrate in the order of an n-type buffer layer, a semiconductor multiplication layer, a p-type semiconductor field buffer layer, a p-type semiconductor light absorbing layer, a p-type semiconductor cap layer, and a p-type semiconductor contact layer, and said p-type semiconductor light absorbing layer is constructed by two layers consisted of a depleted region of a thickness in the range of 10 nm to 0.3 .mu.m disposed adjacent to the p-type semiconductor field buffer layer and a non-depleted layer region at a thickness of less than 2 .mu.m disposed adjacent to the depleted layer region.
    Type: Grant
    Filed: July 1, 1999
    Date of Patent: August 15, 2000
    Assignee: NEC Corporation
    Inventor: Isao Watanabe
  • Patent number: 6080443
    Abstract: A process for producing a MC-type conductive filler includes treating minute metallic particles with a coupling agent, preparing an oil phase of the coupling agent-treated minute metallic particles and a reactive substance A, the reactive substance A directly contacting the metallic particles. Then, an aqueous phase is prepared having a reactive substance B, which is capable of reacting with the reactive substance A, dissolved in water. Thereafter, the oil phase is dispersed in the aqueous phase to form a suspension. In situ reaction of the reactive substances A and B is then caused by applying heat to the suspension or adding a catalyst to the suspension. This forms a coating of a thermosetting insulating resin on the surface of the minute metallic particles. Alternatively, the reactive substance B may not be used.
    Type: Grant
    Filed: December 5, 1997
    Date of Patent: June 27, 2000
    Assignee: Fujitsu Limited
    Inventors: Hiroaki Date, Makoto Usui, Isao Watanabe, Yuko Hozumi
  • Patent number: 6055972
    Abstract: An air-fuel ratio sensor of a limit current type is used for an air-fuel ratio feedback control. When the air-fuel ratio sensor is in a semi-activated state, the air-fuel ratio sensor is driven into an electromotive force generating mode by a current externally applied thereto thereby to shift an electromotive force changing point so that an air-fuel ratio at which the electromotive force changes stepwisely is shifted from the stoichiometric ratio point to a lean zone. When the air-fuel ratio sensor is in a completely activated state, the air-fuel ratio sensor is applied with a voltage to produce a limit current varying with an air-fuel ratio so that a feedback control is performed based on the advanced control theory by using a linear current output characteristics.
    Type: Grant
    Filed: June 30, 1997
    Date of Patent: May 2, 2000
    Assignee: Denso Corporation
    Inventors: Masaya Fujimoto, Minoru Ohta, Makoto Nakae, Isao Watanabe, Naoto Miwa, Hiromi Sano, Masahiro Shibata
  • Patent number: 6045975
    Abstract: The film forming, photosensitive, heat-resistant resin composition comprising a varnish of a polyimide precursor having no photosensitivity in itself, a polymerizable monomer or oligomer compatible with said varnish and capable of providing a high-heat-resistant polymer upon being polymerized, and a polymerization initiator for said monomer or oligomer. The resin composition is useful for the production of circuit substrates and semiconductor devices for high-density mounting including multi-chip modules or the like, such as printed circuits, printed boards, wiring boards and electronic components, since it can effectively avoid a reduction of the layer thickness during the film formation, and ensures a low cost production process. The pattern formation process using the such resin composition is also disclosed.
    Type: Grant
    Filed: May 21, 1993
    Date of Patent: April 4, 2000
    Assignee: Fujitsu Limited
    Inventors: Motoaki Tani, Eiji Horikoshi, Isao Watanabe, Shoichi Miyahara, Takashi Ito, Makoto Sasaki
  • Patent number: 6013419
    Abstract: A method for forming a photosensitive, heat-resistant resin composition film including the step of coating a base material with a varnish made up of a polyimide precursor having no photosensitivity, a photopolymerizable monomer or oligomer capable of providing a high-heat-resistant polymer upon being polymerized, and a polymerization initiator for the monomer or oligomer. The coating is exposed to a light pattern to polymerize the monomer or oligomer in a pattern. The remaining coating is selectively removed from the non-patterned areas. The patterned coating is heat treated to cure the polyimide precursor, thereby forming the film.
    Type: Grant
    Filed: April 6, 1995
    Date of Patent: January 11, 2000
    Assignee: Fujitsu Limited
    Inventors: Motoaki Tani, Eiji Horikoshi, Isao Watanabe, Shoichi Miyahara, Takashi Ito, Makoto Sasaki
  • Patent number: 5972807
    Abstract: A film forming, photosensitive, heat-resistant resin composition including a varnish of a polyimide precursor having no photosensitivity in itself, a polymeriziable monomer or oligomer compatible with the varnish and capable of providing a high-heat-resistant polymer upon being polymerized, and a polymerization initiator for the monomer or oligomer. The resin composition is useful for the production of circuit substrates and semiconductor devices for high-density mounting, since it can effectively avoid a reduction of the layer thickness during film formation, and ensures a low cost production process. The pattern formation process using such a resin composition is also disclosed. The polymeric composite having a particles-in-matrix microstructure and the production process thereof are also disclosed.
    Type: Grant
    Filed: December 23, 1996
    Date of Patent: October 26, 1999
    Assignee: Fujitsu Limited
    Inventors: Motaki Tani, Eiji Horikoshi, Isao Watanabe, Shoichi Miyahara, Takashi Ito, Makoto Sasaki
  • Patent number: 5956841
    Abstract: A heater is inserted into an inside chamber of a sensor element until a tip end of the heater is surely brought into contact with a bottom surface of the inside chamber. Next, a metallic holder is attached on an outside surface of the heater. Then, the metallic holder is slid along the outside surface of the heater toward the bottom surface of the sensor element to engage the metallic holder with an edge of the sensor element.
    Type: Grant
    Filed: January 24, 1997
    Date of Patent: September 28, 1999
    Assignee: Denso Corporation
    Inventors: Isao Watanabe, Michihiro Yamakawa, Masanori Fukutani
  • Patent number: 5900129
    Abstract: An oxygen concentration sensor having excellent sealing performance between a lead wire and a lead wire insertion hole includes a sensor element disposed insertedly into a housing, protective covers disposed at an end portion of the housing, lead wires inserted into the protective covers, and an elastic insulating member disposed inside the protective covers and having a lead wire insertion hole for inserting the lead wires. The lead wire insertion hole in the elastic insulating member has a rib protruding in the radial direction. The elastic insulating member is caulked and fixed by the protective covers.
    Type: Grant
    Filed: June 6, 1996
    Date of Patent: May 4, 1999
    Assignee: Nippondenso Co., Ltd.
    Inventors: Nobuyuki Tsuji, Takashi Kojima, Isao Watanabe, Masahiro Hamaya, Minoru Ohta, Naoto Miwa
  • Patent number: 5886646
    Abstract: For effectively achieving remote a display at long distance by using paging system, there is provided a personal computer, coding information to be transmitted into message code, dividing it into sub-message code which can be transmitted by one time of transmission operation of the paging system, and automatically transmits them in sequence. The message code sent through the paging system is received with a page adapter and input to a display device. The display device interprets the message code and generates display data to perform the display and control thereof.
    Type: Grant
    Filed: December 6, 1996
    Date of Patent: March 23, 1999
    Assignee: Kokusai Electric Co., Ltd.
    Inventors: Isao Watanabe, Ken Watanabe, Yoshichika Watanabe, Osamu Furuya, Yuzo Miura
  • Patent number: 5874664
    Abstract: Air fuel ratio sensor for use in an exhaust gas purification system for an internal combustion engine. The sensor has an outer and inner cover 12 and 13 for protection of lead wires 16, 18 and 19 to a detecting element 3 and a heater 5 of the sensor, a rubber seal for 2 for obtaining a sealing between the covers and the lead wires and a water repellent filter 36 for obtaining a seal between the inner and outer covers 12 and 13, while keeping an air ventilation capability of the space inside the covers. For receiving the lead wires 16, 18 and 19, the seal 2 is formed with holes 20such that the minimum thickness between the holes and the minimum thickness between the hole and an outer surface of the seal is 1 mm or more. A crimping of the outer cover 12 is done so that a deformation of the seal 2 in a range between 10 to 20% of the outer diameter is obtained.
    Type: Grant
    Filed: January 29, 1997
    Date of Patent: February 23, 1999
    Assignee: Denso Corporation
    Inventors: Isao Watanabe, Michihiro Yamakawa, Masanori Fukutani, Toshihiro Sakawa, Nobuyuki Tsuji, Minoru Ohta
  • Patent number: 5862436
    Abstract: A a fixing apparatus for an electrophotographic apparatus includes a heat roller (11a) having a heater (14) therein and a pressure roller (11b) urged against the heat roller, wherein a recording material (6) holding a toner image (25) thereon is sandwiched and carried while being heated and pressurized at a pressing portion between the heat roller and the pressure roller thereby to fix the toner image on a surface of the recording material, the fixing apparatus further including a first temperature detecting mechanism (18) formed by a temperature detecting element (15) provided at a portion of an outer periphery of the heat roller and a sensor head (17) disposed so as to be able oppose to the temperature detecting element, a second temperature detecting mechanism (19) formed by a plurality of temperature detecting elements disposed at a constant interval therebetween along an axial direction of the heat roller and spaced from the outer periphery of the heat roller, and a control mechanism (20, 21, 22, 23, 24)
    Type: Grant
    Filed: October 23, 1997
    Date of Patent: January 19, 1999
    Assignee: Hitachi Koki Co., Ltd.
    Inventors: Katsumi Ishizawa, Shuho Yokokawa, Satoshi Aita, Isao Watanabe, Hidenori Takayasu, Hiroshi Udo
  • Patent number: 5830339
    Abstract: A gas concentration detector comprises a plate sensor element including a sensing action and a signal output section. A flange section is formed between the sensing section and the signal output section so as to protrude in the lateral direction thereof. A cylindrical housing has an inside space for receiving the sensor element. Powder is disposed in the inside space of the cylindrical housing at a predetermined position adjacent to the flange section so that the sensor element is airtightly fixed to the housing by applying a pressing force on the powder. Furthermore, a cross-sectional area of the signal output section is larger than a cross-sectional area of the sensing section.
    Type: Grant
    Filed: October 25, 1996
    Date of Patent: November 3, 1998
    Assignee: Denso Corporation
    Inventors: Isao Watanabe, Masahiro Shibata, Tomio Sugiyama, Syuichi Nakano, Shinichiro Imamura
  • Patent number: 5805953
    Abstract: In order to provide an indication when it is necessary to exchange toner recovery container, an electrophotographic apparatus monitors the accumulated driving time of a toner supply drive unit, and a massage indicating "exchange the toner recovery container" is displayed at the time when a toner supply switch is operated under state in which the accumulated driving time exceeds a preset value.
    Type: Grant
    Filed: November 7, 1996
    Date of Patent: September 8, 1998
    Assignee: Hitachi, Ltd.
    Inventors: Toru Kikuchi, Shuho Yokokawa, Satoshi Aita, Isao Watanabe, Hidenori Takayasu
  • Patent number: 5770835
    Abstract: In accordance with the present invention, there is provided a soldering process comprising the steps of: providing in a furnace first and second heaters each adapted to emit infrared energy; setting a printed circuit boad, which has a solder paste and an electronic component thereon, in the furnace; heating the printed circuit boad with the first heater; and heating the electronic component with the second heater; wherein the first and second heaters have different radiation spectra such that infrared energy irradiated by the first heater is more absorbed by the printed circuit board and less absorbed by the electronic component than that irradiated by the second heater. The present invention also provides a soldering apparatus for use in such soldering process.
    Type: Grant
    Filed: January 7, 1997
    Date of Patent: June 23, 1998
    Assignee: Fujitsu Limited
    Inventors: Seiki Sakuyama, Hiroki Uchida, Isao Watanabe
  • Patent number: 5731106
    Abstract: An electrolytic solution for a lithium secondary battery is provided, which comprises: an electrolyte; an organic solvent; and an additive, wherein the additive is an aromatic nitrogen-containing heterocyclic compound such as pyrazine, quinoxaline, indole, phenazine, phthalazine, pyrimidine, or a mixture thereof.
    Type: Grant
    Filed: May 23, 1996
    Date of Patent: March 24, 1998
    Assignee: Fujitsu Limited
    Inventors: Masami Tsutsumi, Hiroshi Horiuchi, Isao Watanabe, Tsutomu Miyashita
  • Patent number: 5707504
    Abstract: An oxygen concentration detector comprises a housing 10, a detecting element 12 with a built-in heater, a holder 2 made of an insulating ceramic and interposed between the housing and the detecting element 12, and a protecting cover 16 fixed to the housing 10 in such a manner as to cover the outside of the detecting element 12. The protecting cover 16 has gas inlets 160, and a protecting cylinder 21 formed by extending the holder 2 is interposed between the detecting element 12 and the protecting cover 16.
    Type: Grant
    Filed: January 18, 1996
    Date of Patent: January 13, 1998
    Assignee: Nippondenso Co., Ltd.
    Inventors: Kouji Jyouno, Isao Watanabe
  • Patent number: 5688390
    Abstract: A laminated type oxygen concentration sensor includes a laminated type oxygen concentration sensor element having a plate shape with a flange on a side surface thereof, and a housing in a tubular shape having an inclination seat inclined in a central axial direction thereof. The housing supports the laminated type oxygen concentration sensor element by contacting the inclination seat with the flange of the laminated type oxygen concentration sensor element at an outer circumference of the inclination seat. Since the sensor element is supported by contacting the flange with the inclination seat of the housing at the outer circumference of the inclination seat, the pressure per unit area imposed on the sensor element is minimized and cracking of the sensor element is prevented.
    Type: Grant
    Filed: January 11, 1996
    Date of Patent: November 18, 1997
    Assignee: Nippondenso Co., Ltd.
    Inventors: Masanobu Yamauchi, Isao Watanabe, Toshihiro Sakawa
  • Patent number: 5685964
    Abstract: a limiting current type oxygen concentration sensor element includes a measured gas side electrode formed at one side of a solid electrolyte, and a diffusion resistance portion formed on the measured gas side electrode to provide diffusion resistance to passing measured gas therein. The diffusion resistance portion includes a concave portion formed at a position at least corresponding to a position of the measured gas side electrode. In the concave portion, a porous trap layer is disposed to trap contamination in measured gas. The side wall of the concave portion contacts with the trap layer. The area of a contact surface becomes larger than that without the concave portion, which can effectively prevent the trap layer from being peeled off and dropping down. The trap layer can be easily made thicker. By changing the depth of the concave portion appropriately, diffusion resistance of the diffusion resistance portion can be easily adjusted.
    Type: Grant
    Filed: January 11, 1996
    Date of Patent: November 11, 1997
    Assignee: Nippondenso Co., Ltd.
    Inventors: Isao Watanabe, Masahiro Shibata, Masaya Fujimoto
  • Patent number: 5654578
    Abstract: A superlattice avalanche photodiode with a mesa structure is provided, which enables to keep its noise characteristic low for a long time without decreasing the dynamic range for high-speed response. The photodiode has a semiconductor superlattice carrier multiplication layer, a first semiconductor electric-field buffer layers of a first conductivity type formed on one side of the carrier multiplication layer, and a second semiconductor electric-field buffer layer of a second conductivity type formed on the other side of the carrier multiplication layer. The photodiode further has a semiconductor light-absorbing layer of the second conductivity type formed on the second electric-field buffer layer. At least the light-absorbing layer constitutes the mesa structure. The first electric-field buffer layer is made of a central part and a peripheral part surrounding the central part. The peripheral part has a greater electric-field relaxation effect than that of the central part.
    Type: Grant
    Filed: December 21, 1995
    Date of Patent: August 5, 1997
    Assignee: NEC Corporation
    Inventor: Isao Watanabe