Patents by Inventor Takashi Okamoto

Takashi Okamoto 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: 5877603
    Abstract: An electric current control method for a servomotor in which a reactive current is lowered in a region where a voltage saturation does not occur, to suppress generation of heat caused by the reactive current and achieve a stable rotation up to a high-speed region. In the current control of the servomotor using a DQ conversion, an electric current is not supplied to d-phase and supplied only to q-phase when a rotational speed of the servomotor is not high, and the reactive current is supplied to the d-phase only when the rotational speed of the servomotor is high, to thereby lower the terminal voltage of the servomotor by the reactive current. Thus, the reactive current is reduced in the region where the voltage saturation does not occur, to thereby suppress the generation of heat due to the reactive current, and also achieve the stable rotation even in the high-speed region.
    Type: Grant
    Filed: May 13, 1997
    Date of Patent: March 2, 1999
    Assignee: Fanuc Ltd
    Inventors: Hiroyuki Uchida, Yasusuke Iwashita, Yuichi Endo, Takashi Okamoto
  • Patent number: 5829120
    Abstract: A rotor (10) includes a plurality of permanent magnets (14) disposed around a shaft (12) at generally equal intervals, and a plurality of laminated core members (16) disposed between the permanent magnets (14) so as to form magnetic poles. The laminated core members (16) are formed by stacking a plurality of core-laminations (26) made of magnetic materials and an integral core-lamination, and joining them to each other. The integral core-lamination includes a plurality of core-lamination sections each having a shape the same as that of the core-lamination (26), and connecting portions (46) for connecting adjacent core-lamination sections with each other.
    Type: Grant
    Filed: January 6, 1997
    Date of Patent: November 3, 1998
    Assignee: Fanuc, Ltd.
    Inventors: Hiroyuki Uchida, Takashi Okamoto, Hidetoshi Uematsu
  • Patent number: 5786650
    Abstract: A rotor (10) includes a plurality of permanent magnets (14) disposed substantially equidistantly round a shaft (12) and a plurality of laminated core members (16) each being disposed between the permanent magnets (14) and forming a magnetic pole. The laminated core embers (16) are formed by laminating and bonding a large number of thin magnetic plate cores (26) and integral type thin cores. The integral type thin core (26) includes a plurality of thin core portions having the same shape and connecting portions (46) for connecting mutually the adjacent thin core portions. When a large number of thin cores (26) and integral type thin cores are integrally joined by a press work, each laminated core member (16) is mutually interconnected between the adjacent laminated core members (16) with a relative arrangement at the time of completion of assembly having installation spaces of permanent magnets (14), and an integrated type laminate rotor core (48) is formed.
    Type: Grant
    Filed: June 11, 1997
    Date of Patent: July 28, 1998
    Assignee: Fanuc, Ltd.
    Inventors: Hiroyuki Uchida, Takashi Okamoto, Hidetoshi Uematsu
  • Patent number: 5642148
    Abstract: A thermal head apparatus includes a heat generation driving integrated circuit and a current detecting integrated circuit. The heat generation driving integrated circuit is constituted by a plurality of first switching elements respectively connected in series with current detecting resistors, a first shift register for serially inputting print input data for heating heat generation elements, a first latch circuit for latching the print input data input to the first shift register at a predetermined timing, and a first output gate circuit for selectively controlling energization of the first switching elements on the basis of the print input data latched by the first latch circuit.
    Type: Grant
    Filed: November 29, 1994
    Date of Patent: June 24, 1997
    Assignees: NEC Corporation, Susumu Co., Ltd.
    Inventors: Itaru Fukushima, Takashi Okamoto
  • Patent number: 5612105
    Abstract: A biaxially oriented polyamide film which has not only excellent bending pinhole resistance and excellent dimensional stability but also excellent tear linearity in the longitudinal direction of the film. More specifically, the invention provides a biaxially oriented polyamide film having a tear linearity in the longitudinal direction of the film, which includes as a main material nylon 6 and an aliphatic polyamide resin mixed in a weight ratio of from 75:25 to 99:1, wherein the difference in surface tension (dyne/cm) between the nylon 6 and the polyamide other than nylon 6 satisfies the following relationship (1)3.0.ltoreq..gamma..sub.A -.gamma..sub.B .ltoreq.15.0 (1)wherein .gamma..sub.A is a surface tension of N6 and .gamma..sub.B is a surface tension of PA.
    Type: Grant
    Filed: June 5, 1995
    Date of Patent: March 18, 1997
    Assignee: Unitika Ltd.
    Inventors: Takashi Okamoto, Minoru Kishida, Masanobu Hioki, Atsuhiro Ishikawa, Toshikazu Kawakita
  • Patent number: 5422662
    Abstract: A thermal printer head comprises an array of heating elements (1-1.about.1-N) mounted on an insulating base member (20). Each of the heating elements is connected to a common voltage source (V) and has a temperature dependent electrical resistance. Electrically resistive elements (2-1.about.2-N) are respectively connected in series with the heating elements to form a plurality of series circuits. Current supply circuits (3-1.about.3-N, 4-1.about.4-N, 5, 6, 7-1.about.7-N, 14) are provided corresponding respectively to the resistive elements for selectively supplying a current to the series circuits in response to a sequence of print signals. A control circuit (8-11, 14) makes a determination whether a voltage developed across each resistive element is higher or lower than a prescribed threshold value and causes one of the current supply ciruits corresponding to the resistive element to control the current depending on the determination.
    Type: Grant
    Filed: March 25, 1993
    Date of Patent: June 6, 1995
    Assignees: NEC Corporation, Susumu Co., Ltd.
    Inventors: Itaru Fukushima, Nakaba Nakamura, Takashi Okamoto
  • Patent number: 5397951
    Abstract: The present invention provides a rotor for a synchronous rotary machine, having a rotor core (23) provided in its outer circumference with recesses (26), and permanent magnets (25) each fitted radially in each recess (26) so that its lower surface (25b) will be seated on the bottom surface of the recess (26). Each permanent magnet (25) and each recess (26) are formed so that gaps are formed between the inclined side surfaces (27a, 27b) of the permanent magnet (25) and the corresponding inclined side surfaces (26b, 26c) of the recess (26), and an adhesive filling up the gaps is hardened to form wedging layers (30) capable of restraining the permanent magnet (25) from being separated from the surface of the rotor core (23) by forces acting on the permanent magnet (25) to separate the permanent magnet (25) from the surface of the rotor core (23).
    Type: Grant
    Filed: July 19, 1993
    Date of Patent: March 14, 1995
    Assignee: Fanuc Ltd.
    Inventors: Hiroyuki Uchida, Takashi Okamoto
  • Patent number: 5355044
    Abstract: To reduce torque ripples appearing in an output torque of an electric synchronous motor, the rotor (10) is divided into 2.sup.n rotor elements (101, 102, 103, and 104) the rotor elements of each of 2.sup.n-1 pairs of rotor elements (101, 102; 103, 104) being circumferentially shifted from one another around an axis of the rotor by an angle corresponding to a half of the wavelength (.lambda.) of a first (A) of "n" kinds of cyclic torque ripples (A and B) to cancel the first kind of torque ripple, and the 2.sup.n-1 pairs of rotor elements (101, 102; 103, 104) being arranged to be grouped in 2.sup.n.sup.-2 sections of rotor elements, each section including two pairs of rotor elements, and the 2.sup.n-2 sections of rotor elements being circumferentially shifted from one another around the axis of the rotor by an angle corresponding to a half of a wavelength (.lambda.
    Type: Grant
    Filed: January 14, 1992
    Date of Patent: October 11, 1994
    Assignee: Fanuc Limited
    Inventors: Hiroyuki Uchida, Tomonaga Yamamoto, Takashi Okamoto
  • Patent number: 5233342
    Abstract: A remote control system is employed with a view to realization of automated/unattended control in supervisory control of power equipment, transportion/traffic equipment, building equipment, home equipment, and the like. This remote control system includes a priority rank determination unit and a control unit on the controlled side where a control signal for controlling the operation of a plurality of electric equipment is inputted through a communication system from the control side. The priority rank determination unit determines an operating priority rank of respective electric equipments on the basis of respective power dissipations of the plurality of electric equipments. The control unit operates respective electric equipments on the basis of the operating priority rank thus determined. By controlling the operation of the electric equipment in this way, an accident of interruption of the operation of the entire system resulting from the operation of a specific electric equipment is prevented.
    Type: Grant
    Filed: February 20, 1991
    Date of Patent: August 3, 1993
    Assignee: Pioneer Electronic Corporation
    Inventors: Kenji Yashiro, Takashi Okamoto
  • Patent number: 5226796
    Abstract: A valve assembly in a piston type refrigerant compressor is disclosed. The valve assembly includes a retainer formed integrally with a gasket plate for restricting the opening of a discharge reed valve of the compressor, and having on opposite sides at the distal portion thereof stay portions integral with the gasket plate for rigidly holding the retainer. According to the present invention, provision is made to guide some part of the refrigerant gas compressed in a cylinder bore to be discharged into a discharge chamber in such a way that the influence of the discharge gas pressure on the retainer at its distal end is reduced. In some embodiments of the invention, this is accomplished by guiding and allowing part of the gas to flow toward the proximal portion of the retainer to discharge the gas.
    Type: Grant
    Filed: October 25, 1991
    Date of Patent: July 13, 1993
    Assignee: Kabushiki Kaisha Toyoda Jidoshokki Seisakusho
    Inventors: Takashi Okamoto, Atsushi Fukaya, Katsunori Kawai, Hayato Ikeda
  • Patent number: 5185855
    Abstract: A curved surface designing method comprises the steps of a first step of inputting edge shape data of n-sides of a curved surface, a second step of obtaining a regular n-sided polygon in a parameter space on the basis of the given data of n sides, a third step of calculating distance parameters on the basis of the regular n-sided polygon obtained by the second step, a fourth step of calculating blending values on the basis of the distance parameters, a fifth step of mapping an inner point D of the regular n-sided polygon onto the respective sides so as to calculate boundary parameters, a sixth step of calculating at least one of three-dimensional coordinate points, and, if necessary, tangent vectors, on sides which are boundaries of the curved surface on the basis of the boundary parameters, and a seventh step of calculating arbitrary points on the curved surface on the basis of the distance parameters, the blending values, the three-dimensional coordinate points of the respective sides, and, if necessary, th
    Type: Grant
    Filed: October 7, 1991
    Date of Patent: February 9, 1993
    Assignee: Mitsubishi Denki K.K.
    Inventors: Kiyotaka Kato, Takashi Okamoto
  • Patent number: 5076764
    Abstract: A swash plate type compressor having axially spaced inlet chambers and outlet chambers located on the side of angularly spaced pistons having each side thereof pump chambers which are connected to inlet chamber when the medium is introduced into the pump chambers, and are connected to the outlet chamber when the medium is removed to the outlet chambers. A swash plate chamber is arranged inside the cylinder block and cooperates with the pistons via respective shoes for reciprocating the pistons in the respective cylinder bores. An inlet of the fluid to be compressed is opened to the swash plate chamber at a circumferential position along the inner wall of the swash plate chamber. Communication passageways for connection of the swash plate chamber with the inlet chambers are arranged on position spaced farthest from the inlet port.
    Type: Grant
    Filed: August 30, 1990
    Date of Patent: December 31, 1991
    Assignee: Kabushiki Kaisha Toyoda Jidoshokki Seisakusho
    Inventors: Katsunori Kawai, Takashi Okamoto, Shinichi Ishihara, Hitoshi Inuka
  • Patent number: 4981419
    Abstract: A thrust bearing assembly of a wobble plate type refrigerant compressor for supporting a non-rotatable inclined wobble plate on a rotatable drive element which rotates with a drive shaft, and having a inclined drive face able to convert a rotating motion of the drive element into a wobbling motion of the wobble plate to thereby cause a reciprocation of compression pistons in cylinder bores, the thrust bearing assembly having a plurality of roller elements, an annular retainer elements holding the roller elements therein and rotating in a space between the drive face of the drive element and an inclined face of the wobble plate confronting the drive face, a pair of race elements attached to the drive and inclined faces of the drive element and the wobble plate to provide raceways for rolling of the roller elements, and a circumferentially extended guide way element supplying the annular retainer elements with a constant slide guide during the operation of the compressor irrespective of a change in the operatin
    Type: Grant
    Filed: August 15, 1989
    Date of Patent: January 1, 1991
    Assignee: Kabushiki Kaisha Toyoda Jidoshokki Seisakusho
    Inventors: Hiroaki Kayukawa, Kenji Takenaka, Takashi Okamoto, Akihiko Hyodo
  • Patent number: 4878065
    Abstract: A thermal printing control circuit includes a first shift register for receiving and storing a series of serial printing image data to be printed by a plurality of thermal print elements, a second register, constituted by a plurality of registers for storing contents of the first shift register by parallelly and sequentially shifting and receiving the contents thereof, for storing printing history data of a plurality of cycles of the thermal print elements, and a logic circuit for performing a logic operation by using the printing history data of the plurality of cycles of the plurality of thermal print elements, the printing history data being stored in the second shift register, and externally supplied control timing signals and for generating drive signals representing voltage waveforms to be applied to the plurality of thermal print elements.
    Type: Grant
    Filed: August 26, 1988
    Date of Patent: October 31, 1989
    Assignees: NEC Corporation, Susumu Corporation, Ltd.
    Inventors: Itaru Fukushima, Takashi Okamoto, Hisashi Deguchi
  • Patent number: 4811281
    Abstract: A work station of a computer system capable of batch storing and retrieving image data separately from a usual data file system, equipped with a main processor, main processor memory and direct memory access (DMA) controller connected to a common bus, equipped with a graphic processor and window memory between the common bus and an image data bus, and equipped with a frame memory in connection with an image display unit on the image data bus, wherein the work station is further provided with an image data memory, e.g., disk unit, on the image data bus, a memory input/output controller lcoated between the image data memory and the image data bus for controlling image data transfer using a direct memory access (DMA) function, and an image data input unit and output unit connected to the memory input/output controller, so that mass image data can be transferred directly between the memory and input/output units under control of the memory input/output controller without going through the window memory.
    Type: Grant
    Filed: February 19, 1987
    Date of Patent: March 7, 1989
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Takashi Okamoto, Akio Terasawa, Takashi Ishizaki
  • Patent number: 4804707
    Abstract: A resin composition which comprises a resin blend comprising from 10 to 70% by weight of a polyarylate and from 30 to 90% by weight of a polyamide, and (A) an epoxy group-containing olefin copolymer obtained by copolymerizing at least one unsaturated glycidyl monomer with at least one olefin unsaturated monomer and (B) an acid anhydride-containing olefin copolymer obtained by copolymerizing a polyolefin or an olefin copolymer with an unsaturated dicarboxylic anhydride, incorporated in a total amount of form 3 to 30% by weight to said resin blend.
    Type: Grant
    Filed: April 24, 1987
    Date of Patent: February 14, 1989
    Assignee: Unitika Ltd.
    Inventors: Takashi Okamoto, Kenji Yasue, Takeshi Marutani, Yasumasa Fukushima
  • Patent number: 4791342
    Abstract: In a numerical control device for machine tools, a tool path is determined for a workpiece according to the machining data, and is divided into machining units, and the amount of machining for each machining unit is calculated to set a tool feeding speed data thereby to control the tool feeding speed of the machine tool.
    Type: Grant
    Filed: June 19, 1987
    Date of Patent: December 13, 1988
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Takashi Okamoto
  • Patent number: 4756239
    Abstract: An anti-rolling structure for a double headed piston of a disc cam type reciprocative compressor, comprising a cylinder block (1) through which a plurality of pairs of front and rear cylinder bores (4) are provided in parallel to a drive shaft (3) rotatably secured in the center of the cylinder block (1), and a double headed piston (8) slidably inserted in the respective pair of cylinder bores (4) for reciprocation in the longitudinal direction. A disc cam (13) having opposite sinuous surfaces (13') and rotatably accommodated within a cam chamber (5) is fixedly secured to the drive shaft (3), and a pair of front and rear cam rollers (14F, 14R) are arranged between the disc cam (13) and the piston (8) in a slidable and rotatable manner so as to nip the disc cam (13) between both cam rollers (14F, 14R) to transmit the rotation of the disc cam (13) to the piston (8) as a reciprocation in the longitudinal direction thereof.
    Type: Grant
    Filed: November 18, 1987
    Date of Patent: July 12, 1988
    Assignee: Kabushiki Kaisha Toyoda Jidoshokki Seisakusho
    Inventors: Mitsuhiro Hattori, Katsunori Kawai, Masayuki Tanikawa, Takashi Okamoto
  • Patent number: 4699973
    Abstract: A polyamide film prepared from a polyamide composition comprised of at least 60% by weight of polytetramethyleneadipamide or a copolymer polyamide containing at least 60% by weight of a polytetramethyleneadipamide component, said film being at least monoaxially stretched at a stretching ratio of at least 1.5, said film having a characteristic value .DELTA.T of from 30.degree. to 60.degree. C. as determined from the relationship:.DELTA.T=Tm-Tc,wherein Tm (melting point) is the peak melting temperature (.degree.C.) when the temperature is increased at a rate of 20.degree. C./min by means of a differential scanning calorimeter (DSC) and Tc (crystallization temperature) is the peak crystallization temperature (.degree.C.) when the temperature, 20.degree. C. above the melting point, is decreased at a rate of 80.degree. C./min by means of a DSC, and said film having a retention rate of its breaking strength after a hydrothermal treatment at 135.degree. C. for 30 minutes of at least 60%.
    Type: Grant
    Filed: May 2, 1986
    Date of Patent: October 13, 1987
    Assignee: Unitika Ltd.
    Inventors: Kojiro Ito, Takashi Okamoto, Kunio Murakami, Minoru Kishida
  • Patent number: 4659757
    Abstract: A polyester resin composition for forming an impact resistant article is described, comprising from 40 to 97 parts by weight of polyethylene terephthalate and from 3 to 60 parts by weight of at least one polyester selected from(1) an ethylene terephthalate-based polyester comprising from 5 to 25 wt % of at least one dibasic acid represented by formula (I) ##STR1## wherein A and B each represents a hydrogen atom, an alkyl group, or a phenyl group, and n is an integer of not less than 10, and ester bond-forming derivatives,(2) an ethylene terephthalate-based polyester comprising 3 to 25 wt % of at least one polyalkylene glycol having a molecular weight of from about 500 to 20,000, and(3) polyarylate, which composition further contains, per 100 parts by weight of the polyester, (a) from 0.05 to 10 parts by weight of at least one of an inorganic crystal nucleating agent having an average particle diameter of not more than 50 .mu.
    Type: Grant
    Filed: March 7, 1986
    Date of Patent: April 21, 1987
    Assignee: Unitika Ltd.
    Inventors: Takashi Okamoto, Fumio Ohama