Patents by Inventor Kazuyuki Itoh

Kazuyuki Itoh 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).

  • Publication number: 20240117192
    Abstract: A method for manufacturing a surface-treated gas-phase-process silica particle, the method including steps of: adding 1,3-divinyl-1,1,3,3-tetramethyldisilazane to a raw material gas-phase-process silica particle and introducing a vinyldimethylsilyl group on a surface of the raw material gas-phase-process silica particle to obtain a preliminarily treated silica particle; and adding hexamethyldisilazane to the preliminarily treated silica particle and introducing a trimethylsilyl group on a surface of the preliminarily treated silica particle to obtain a surface-treated gas-phase-process silica particle.
    Type: Application
    Filed: December 22, 2021
    Publication date: April 11, 2024
    Applicant: SHIN-ETSU CHEMICAL CO., LTD.
    Inventors: Kazuyuki MATSUMURA, Masanobu NISHIMINE, Yusuke ITOH, Hisashi YAGI, Tsutomu NAKAMURA, Yoshiteru SAKATSUME
  • Patent number: 7049793
    Abstract: The present invention provides a boost switching power supply with low switching loss. The boost switching power supply of the present invention includes a coil portion 3a and a first diode 4 that are serially connected between one terminal of a DC power source 2 and one terminal of a first capacitor 5 for smoothing, a first switching element 8 connected between a node A where the coil portion 3a and the first diode 4 are connected and the other terminal of the DC power source 2, a second magnetic element 7 and a second switching element 9 that are serially connected between the node A and the other terminal of the DC power source 2, and a second diode 10 and a second capacitor 11 that are serially connected between a node where the second magnetic element 7 and the second switching element 9 are connected and the node A.
    Type: Grant
    Filed: September 19, 2001
    Date of Patent: May 23, 2006
    Assignee: TDK Corporation
    Inventors: Kazuyuki Itoh, Katsuaki Tanaka
  • Patent number: 6945605
    Abstract: A chair includes a seat portion 1(1B), a seat support 2(2B) supporting the seat portion 1, a rear seat support 3(3B) extending rearwardly upwardly relative to the seat support 2(2B), and a slide mechanism X1 (moving mechanism XB) for causing the seat portion 1(1B) to slide back and forth relative to the seat support 2 (2B). The chair is provided with a locking mechanism 100C for locking the seat portion 6C at a desired position in the fore-and-aft direction selectively, and a lever 110C for operating the locking mechanism 100C, the lever 110C being located at a position allowing the lever 110C to move together with the seat portion 6C in the fore-and-aft direction.
    Type: Grant
    Filed: October 9, 2001
    Date of Patent: September 20, 2005
    Assignees: Kokuyo Co., Ltd., Takano Co., Ltd.
    Inventors: Yojiro Kinoshita, Nobuyuki Ueda, Toshiyuki Horiki, Kazuyuki Itoh, Hiroyuki Nishimura
  • Patent number: 6739664
    Abstract: A chair 1 allowing a person sitting thereon to move a part of the person's body above the waist which corresponds to the backrest of the chair is provided having a backrest portion located behind a seat portion, the backrest portion being divided into backrest upper frames 55 and backrest lower frames 50, wherein a first state which allows the whole backrest frame 5 to incline rearwardly and a second state which allows the backrest upper frames 55 to incline rearwardly relative to the backrest lower frames 50 are assumed, the first state and the second state being switchable to each other.
    Type: Grant
    Filed: May 23, 2002
    Date of Patent: May 25, 2004
    Assignees: Kokuyo Co., Ltd., Takano Co., Ltd.
    Inventors: Yojiro Kinoshita, Nobuyuki Ueda, Toshiyuki Horiki, Kazuyuki Itoh
  • Publication number: 20040036451
    Abstract: The present invention provides a boost switching power supply with low switching loss. The boost switching power supply of the present invention includes a coil portion 3a and a first diode 4 that are serially connected between one terminal of a DC power source 2 and one terminal of a first capacitor 5 for smoothing, a first switching element 8 connected between a node A where the coil portion 3a and the first diode 4 are connected and the other terminal of the DC power source 2, a second magnetic element 7 and a second switching element 9 that are serially connected between the node A and the other terminal of the DC power source 2, and a second diode 10 and a second capacitor 11 that are serially connected between a node where the second magnetic element 7 and the second switching element 9 are connected and the node A.
    Type: Application
    Filed: March 11, 2003
    Publication date: February 26, 2004
    Inventors: Kazuyuki Itoh, Katsuaki Tanaka
  • Patent number: 6614667
    Abstract: A power conversion apparatus capable of reducing the conduction loss to achieve high efficiency yielding a downsized and weight-reduced apparatus and a method for driving such a power conversion apparatus is disclosed. A power conversion apparatus comprising a switching-element driving circuit which includes a current transformer having a primary coil connected to an current control type switching element, and a driving-current generating circuit formed of a secondary coil of the current transformer and a rectifying circuit connected to the secondary coil, wherein an output current generated in the driving-current generating circuit is supplied to the switching element as a driving current of the switching element, and a method for driving the switching element of such a power conversion apparatus are disclosed.
    Type: Grant
    Filed: April 23, 2001
    Date of Patent: September 2, 2003
    Assignee: TDK Corporation
    Inventors: Kazuyuki Itoh, Yoshihisa Okita, Katsuaki Tanaka, Yoshinobu Takayanagi
  • Publication number: 20020190554
    Abstract: A chair 1 allowing a person sitting thereon to move a part of the person's body above the waist which corresponds to the backrest of the chair is provided having a backrest portion located behind a seat portion, the backrest portion being divided into backrest upper frames 55 and backrest lower frames 50, wherein a first state which allows the whole backrest frame 5 to incline rearwardly and a second state which allows the backrest upper frames 55 to incline rearwardly relative to the backrest lower frames 50 are assumed, the first state and the second state being switchable to each other.
    Type: Application
    Filed: May 23, 2002
    Publication date: December 19, 2002
    Inventors: Yojiro Kinoshita, Nobuyuki Ueda, Toshiyuki Horiki, Kazuyuki Itoh
  • Publication number: 20020180248
    Abstract: A chair comprising a seat (1(1B)), a seat support (2(2B)) for supporting the seat (1), a rear seat support (3(3B)) extending upwardly rearwardly of the seat support (2(2B)), and a slide mechanism (X1) (moving mechanism (XB)) for sliding the seat (1(1B)) back and forth with respect to the seat support (2 (2B)). Further, a seat (6C) is provided with a fixing mechanism (100C) for fixing it at a desired longitudinal position, and a lever (110C) for operating the fixing mechanism (100C) is installed at a position which allows longitudinal movement thereof together with the seat (6C).
    Type: Application
    Filed: May 23, 2002
    Publication date: December 5, 2002
    Inventors: Yojiro Kinoshita, Nobuyuki Ueda, Toshiyuki Horiki, Kazuyuki Itoh, Hiroyuki Nishimura
  • Publication number: 20020180252
    Abstract: In order to improve operationality to produce functions, to prevent an assembling or disassembling procedure from being complicated and to simplify a structure of a chair of multi-function, a chair having a plurality of operating portions to adjust a height of a back or a seat or to adjust a rocking motion mechanically is so arranged that each of more than two operating portions as some or all of the operating portions is made to rotate around a predetermined shaft respectively, each shaft of the operating portions is arranged in a line, and more than two operating portions as some or all of the operating portions are arranged in a line and the chair comprises an operation receiving portion as a mechanism to work each mechanism directly and a link means that connects the operating portion and the operation receiving portion, some or all of the adjusting portions that are arranged in the link means in order to adjust a motion range of the operation receiving portion that works with operation of the operating p
    Type: Application
    Filed: May 23, 2002
    Publication date: December 5, 2002
    Inventors: Yojiro Kinoshita, Nobuyuki Ueda, Toshiyuki Horiki, Kazuyuki Itoh, Fritz Frenkler, Anette Ponholzer
  • Patent number: 6438004
    Abstract: The present invention discloses a power conversion apparatus comprising a control circuit for generating a switching signal at the timing allowing soft-switching to be achieved, and free from any occurrence of ripple. The power conversion apparatus includes a first main switch (Q1) and a second main switch (Q2) which are connected in series with each other. One of the ends of the first main switch is connected with the positive side of a DC power supply, and one of the ends of the second main switch is connected to the negative side of the DC power supply. A diode (D1, D2) is connected in parallel with each of the main switches so as to become reverse biased with respect to the DC power supply. A main-switch snubber capacitor (C1, C2) is connected in parallel with each of the main switches. A load is connected with the junction between the pair of main switches, and the main switches are controllably switched according a switching signal from a control circuit to generate an output.
    Type: Grant
    Filed: December 26, 2001
    Date of Patent: August 20, 2002
    Assignee: TDK Corporation
    Inventors: Katsuaki Tanaka, Yoshihisa Okita, Kazuyuki Itoh
  • Patent number: 6414854
    Abstract: In a power conversion apparatus using a semiconductor switching element, a collector-emitter voltage detecting device is provided to detect the collector-emitter voltage in the semiconductor switching element in the power conversion apparatus in order to comprehensively reduce switching loss and conduction loss arising in a switching element. A base current supplied to the switching element is controlled based on the detected collector-emitter voltage so as to control the collector-emitter voltage or control a regenerative power to be transmitted from a switching element driving power supply to an external auxiliary power supply or the like. This provides an optimum driving in consideration of factors including dispersion in a specific current amplification factor (hfe) of the switching element, variance in the hfe caused by temperature, and variance in the hfe to a current flowing through the switching element, for reducing a sum of conduction loss and driving power of the switching element.
    Type: Grant
    Filed: September 7, 2001
    Date of Patent: July 2, 2002
    Assignee: TDK Corporation
    Inventors: Kazuyuki Itoh, Yoshihisa Okita, Katsuaki Tanaka, Yoshinobu Takayanagi
  • Patent number: 6411078
    Abstract: It is an object of the invention to provide a current sensor apparatus that reduces measurement errors resulting from variations in a position of a current path passing through the space inside a magnetic yoke. The current sensor apparatus comprises a ring-shaped magnetic yoke (2) surrounding a current path (1), part of the yoke having a gap (3), and a magnetic sensor element (4) placed in the gap (3) of the magnetic yoke (2). The magnetic sensor element (4) detects a magnetic field in the gap (3) generated by a current flowing through the current path (1) to measure the current flowing through the current path (1). The current sensor apparatus further comprises a magnetic field interrupter (5), placed between the current path (1) and the gap (3), for interrupting a magnetic field corresponding to a magnetic flux generated by the current passing through the current path (1) and not passing through the magnetic yoke (2), so that the magnetic field would not reach the magnetic sensor element (4).
    Type: Grant
    Filed: January 20, 2000
    Date of Patent: June 25, 2002
    Assignee: TDK Corporation
    Inventors: Shiro Nakagawa, Kazuyuki Itoh, Katsuaki Tanaka, Katsumi Yabusaki
  • Publication number: 20020054499
    Abstract: The present invention discloses a power conversion apparatus comprising a control circuit for generating a switching signal at the timing allowing soft-switching to be achieved, and free from any occurrence of ripple.
    Type: Application
    Filed: December 26, 2001
    Publication date: May 9, 2002
    Applicant: TDK CORPORATION
    Inventors: Katsuaki Tanaka, Yoshihisa Okita, Kazuyuki Itoh
  • Patent number: 6353543
    Abstract: A switching circuit for a power conversion apparatus capable of reducing conduction loss to provide a higher efficiency, and achieving downsizing and weight-reduction and higher driving frequency based on the improved efficiency is disclosed. A driving transistor is connected to a switching main transistor to supply a driving power for ON-OFF driving thereto, and an auxiliary power source composed of a current transformer is provided between the main transistor and the driving transistor. An auxiliary transistor having a lower switching loss than that of the main transistor is connected in parallel with the main transistor to form a main switch in combination with the main transistor. A current-driven type transistor serves as the main transistor, and voltage-driven type transistors serve as both of the driving transistor and the auxiliary transistor.
    Type: Grant
    Filed: May 14, 2001
    Date of Patent: March 5, 2002
    Assignee: TDK Corporation
    Inventors: Kazuyuki Itoh, Yoshihisa Okita, Katsuaki Tanaka
  • Publication number: 20020012253
    Abstract: In a power conversion apparatus using a semiconductor switching element, a collector-emitter voltage detecting device is provided to detect the collector-emitter voltage in the semiconductor switching element in the power conversion apparatus in order to comprehensively reduce switching loss and conduction loss arising in a switching element. A base current supplied to the switching element is controlled based on the detected collector-emitter voltage so as to control the collector-emitter voltage or control a regenerative power to be transmitted from a switching element driving power supply to an external auxiliary power supply or the like. This provides an optimum driving in consideration of factors including dispersion in a specific current amplification factor (hfe) of the switching element, variance in the hfe caused by temperature, and variance in the hfe to a current flowing through the switching element, for reducing a sum of conduction loss and driving power of the switching element.
    Type: Application
    Filed: September 7, 2001
    Publication date: January 31, 2002
    Inventors: Kazuyuki Itoh, Yoshihisa Okita, Katsuaki Tanaka, Yoshinobu Takayanagi
  • Patent number: 6316931
    Abstract: It is an object of the invention to provide a magnetic sensor and a current sensor that exhibit high performance at low costs. A magnetic sensor has a magnetic core (1) having a magnetic saturation property and a sensor coil (2) wound around the magnetic core (1). An end of a detection coil (20) is connected to an end of the sensor coil (2). The other end of the detection coil (20) is grounded. The magnetic sensor further comprises a drive circuit (3) and a detection circuit (4). The drive circuit (3) has a series resonance circuit part of which is made up of the sensor coil (2). To the sensor coil (2) the drive circuit (3) supplies a resonance current flowing into the series resonance circuit as an alternating current that allows the magnetic core (1) to reach a saturation region. The detection circuit (4) detects a magnetic field to be measured by detecting variations in resonance current flowing through the sensor coil (2).
    Type: Grant
    Filed: January 18, 2000
    Date of Patent: November 13, 2001
    Assignee: TDK Corporation
    Inventors: Shiro Nakagawa, Kazuyuki Itoh, Yoshihisa Okita, Katsumi Yabusaki
  • Publication number: 20010038540
    Abstract: A switching circuit for a power conversion apparatus capable of reducing conduction loss to provide a higher efficiency, and achieving downsizing and weight-reduction and higher driving frequency based on the improved efficiency is disclosed. A driving transistor is connected to a switching main transistor to supply a driving power for ON-OFF driving thereto, and an auxiliary power source composed of a current transformer is provided between the main transistor and the driving transistor. An auxiliary transistor having a lower switching loss than that of the main transistor is connected in parallel with the main transistor to form a main switch in combination with the main transistor. A current-driven type transistor serves as the main transistor, and voltage-driven type transistors serve as both of the driving transistor and the auxiliary transistor.
    Type: Application
    Filed: May 14, 2001
    Publication date: November 8, 2001
    Inventors: Kazuyuki Itoh, Yoshihisa Okita, Katsuaki Tanaka
  • Patent number: 6208541
    Abstract: This PWM inverter apparatus includes a first and second current control type semiconductor switching elements connected in series which are connected in parallel to a DC power supply. An output is generated by alternately switching the first and second semiconductor switching elements. Resistive semiconductor switching elements having a higher switching speed than the first and second semiconductor switching elements and a resistance-to-current characteristics producing a voltage drop are respectively connected in parallel to respective the first and second semiconductor switching elements.
    Type: Grant
    Filed: June 22, 2000
    Date of Patent: March 27, 2001
    Assignee: TDK Corporation
    Inventors: Kazuyuki Itoh, Yoshihisa Okita, Katsuaki Tanaka
  • Patent number: 5547369
    Abstract: A camera includes a plurality of photosensors disposed on an imaging surface. The photosensors separately output respective photodetection signals, and are grouped into a plurality of photosensitive units each including at least two of the photosensors. The photosensors of each of the photosensitive units have respective detection wavelength ranges which do not overlap one another. The photodetection signals outputted from selected ones of the photosensors of each of the photosensitive units are used in performing spectrum analysis. R (red), G (green), and B (blue) signals are synthesized from the photodetection signals outputted from the photosensors of each of the photosensitive units and are used in displaying an ordinary color image.
    Type: Grant
    Filed: March 17, 1994
    Date of Patent: August 20, 1996
    Assignee: Hitachi, Ltd.
    Inventors: Kenichi Sohma, Kazuyuki Itoh, Michio Kuroda, Tadayoshi Murakami
  • Patent number: D436085
    Type: Grant
    Filed: June 18, 1999
    Date of Patent: January 9, 2001
    Assignee: Fujikura, Ltd.
    Inventors: Takashi Takizawa, Tatsuya Itoh, Kazuyuki Itoh