Patents by Inventor Akihiro Yonezawa

Akihiro Yonezawa 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: 11054879
    Abstract: The present invention achieves high speed safe response performance. A safety controller (100) includes a first voltage monitoring circuit (12) and a second voltage monitoring circuit (22). The first voltage monitoring circuit (12) is an AD converter which operates upon receiving electric power from a second electric power source (21) and which transmits, to a second MPU (20), a signal that gives notification of occurrence of an anomaly in a first voltage value. The second voltage monitoring circuit (22) is an AD converter which operates upon receiving electric power from a first electric power source (11) and which transmits, to a first MPU (10), a signal that gives notification of occurrence of an anomaly in a second voltage value.
    Type: Grant
    Filed: October 2, 2018
    Date of Patent: July 6, 2021
    Assignee: OMRON Corporation
    Inventors: Keiichi Teranishi, Daisuke Yagi, Akihiro Yonezawa, Shotaro Koga
  • Publication number: 20200249741
    Abstract: The present invention achieves high speed safe response performance. A safety controller (100) includes a first voltage monitoring circuit (12) and a second voltage monitoring circuit (22). The first voltage monitoring circuit (12) is an AD converter which operates upon receiving electric power from a second electric power source (21) and which transmits, to a second MPU (20), a signal that gives notification of occurrence of an anomaly in a first voltage value. The second voltage monitoring circuit (22) is an AD converter which operates upon receiving electric power from a first electric power source (11) and which transmits, to a first MPU (10), a signal that gives notification of occurrence of an anomaly in a second voltage value.
    Type: Application
    Filed: October 2, 2018
    Publication date: August 6, 2020
    Applicant: OMRON Corporation
    Inventors: Keiichi TERANISHI, Daisuke YAGI, Akihiro YONEZAWA, Shotaro KOGA
  • Patent number: 5668440
    Abstract: In a discharge lamp having a discharge medium sealed in a discharge tube assembly including electrodes for producing a discharge, a nitride layer is formed on a surface of an envelope tube of the discharge tube assembly. The nitride layer is formed by substituting an oxygen component of an oxide constituting the tube wall of the envelope tube with nitrogen, and exhibits a continuous and smooth reduction in nitride content in the direction of depth. This chemically stable nitride layer prevents a reaction between the discharge medium and the tube wall material, and removal or injection of the discharge medium. In addition, since the nitride layer also exhibits a continuous change in thermal expansion coefficient in the direction of depth, the thermal stress is reduced, and cracking, peeling, removal, and the like do not occur.
    Type: Grant
    Filed: May 17, 1995
    Date of Patent: September 16, 1997
    Assignee: Toshiba Lighting & Technology Corporation
    Inventors: Shinji Inukai, Kazuo Takita, Makoto Nishizawa, Akira Itoh, Kazuyoshi Okamura, Kazuiki Uchida, Takayuki Aoki, Kazuhiko Yoshikawa, Akihiro Yonezawa, Hiroki Sasaki
  • Patent number: 5187413
    Abstract: A low pressure discharge lamp apparatus has a low pressure discharge lamp with an arc tube. The arc tube has a first end and a second end, each with electrodes which define a discharge space therebetween. A mercury/rare gas is sealed in the arc tube. The low pressure discharge lamp apparatus further has a lighting circuit apparatus for lighting the lamp by supplying a current with a polarity reversed for each half cycle to electrodes in the first and second ends of the arc tube. The lighting circuit apparatus supplies, to the lamp, a current whose waveform has a flat peak for each half cycle and a maximum current value of the current is restricted to less than a level in which the excitation of mercury atoms is saturated.
    Type: Grant
    Filed: August 30, 1991
    Date of Patent: February 16, 1993
    Assignee: Toshiba Lighting & Technology Corporation
    Inventors: Kenji Araki, Hiroki Sasaki, Akihiro Yonezawa, Youichirou Mitsuyuki
  • Patent number: 4929869
    Abstract: In order to maintain an ultraviolet-ray intensity of a metal halide lamp for a long period, the present invention provides a high intensity discharge lamp comprising an arc tube having electrodes at its both ends, and a rare gas, mercury, iron, a halogen and silver enclosed in the tube, wherein a gram atom ratio of silver to iron is 0.05 to 0.2. The present invention also provides a high intensity discharge lamp comprising an arc tube having electrodes at its both ends, and a rare gas, mecury, iron, a halogen, tin and silver enclosed in the tube, wherein ([Fe]+[Sn])/[J]<0.5 and (2[Fe]+2[Sn]+[Ag])/[J]>1, where [Fe], [Sn], ]Ag] and [J] are, respectively, gram atoms of iron, tin, silver and the halogen.
    Type: Grant
    Filed: November 10, 1988
    Date of Patent: May 29, 1990
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Akihiro Yonezawa, Hiroki Sasaki, Yoichiro Mitsuyuki, Yasuki Mori, Toshihiko Ishigami
  • Patent number: 4835442
    Abstract: A high-efficacy, high power ultraviolet radiation lamp is disclosed. Electrodes are respectively provided at two ends of a discharge tube, and at least a rare gas is sealed in the discharge tube. The discharge tube is curved in a U shape. A reservoir for reserving a radiant material for radiating ultraviolet rays projects from the discharge tube. An isolating section is provided to surround at least the reservoir. The isolating section adjusts the temperature of the reservoir and supplies an appropriate amount of radiant material into the discharge tube.
    Type: Grant
    Filed: January 27, 1988
    Date of Patent: May 30, 1989
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takahiro Sugimoto, Hiroki Sasaki, Akihiro Yonezawa, Youichiro Mitsuyuki
  • Patent number: 4800321
    Abstract: A high pressure sodium lamp includes an arc tube having an inner diameter greater than 12 mm. An amalgam including a prescribed quantity of sodium and mercury is sealed in the arc tube. To achieve the maximum lamp efficiency in different values of the inner diameter of the arc tube, the lamp should satisfy the following relationships:(10.sup.0.848 .phi..sup.(-0.171) log X+(0.105.phi.-10.22)<log Y<(10.sup.0.848 .phi..sup.(-0.171) log X-10.sup.1.43 .phi..sup.(-0.574)), and(-7.97 log.phi.+14.8)<log .DELTA.V<(84.7 log.phi.-84.5)where .phi. (mm) is the inner diameter of the arc tube, X (wt %) is the ratio of the quantity of sodium to the quantity of amalgam sealed in the arc tube, Y (mg/cc) is the quantity of sodium sealed in the arc tube, and .DELTA.V (v/cm) is the electric field strength when the lamp is operated.
    Type: Grant
    Filed: August 5, 1987
    Date of Patent: January 24, 1989
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yujiro Ike, Akihiro Yonezawa, Shinichi Ooshima, Akihiro Kamiya, Yoshio Hirose
  • Patent number: 4419602
    Abstract: The molybdenum foil coupling member is disclosed in which potassium (K) and silicon dioxide (SiO.sub.2) are respectively dispersed in the range from 200 to 800 ppm and from 200 to 2000 ppm so as to resist to fracturing upon exposed to high temperature. This coupling member is particularly well suited for used in electric lamps having quartz glass envelopes which are pinch sealed at either end.
    Type: Grant
    Filed: January 21, 1982
    Date of Patent: December 6, 1983
    Assignee: Tokyo Shibaura Denki Kabushiki Kaisha
    Inventors: Zenzou Mitamura, Takashi Oosawa, Akihiro Yonezawa