Patents by Inventor Tetsuroh Kawai

Tetsuroh Kawai 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).

  • Flow control device
    Patent number: 8800592
    Abstract: In a flow control device 100, a comparator 40 outputs a first control voltage Vref based on a comparison of an instruction value signal Vi1 of the flow volume and a signal Vi2 according to the sensor output signal Vs. A feedback current generator 30 generates a feedback current Ifb according to a difference between the sensor output signal Vs and a signal Vi2 according to the instruction value signal Vi1. A feedback voltage generator 50 is a resister. A feed forward current generator 20 generates a feed forward current Iff according to the instruction value signal Vi1. A synthesis unit 60 generates a second control voltage Vdrv* obtained by adding to the feedback voltage Vfb a voltage according to a sum of the feedback current Ifb and the feed forward current Iff. The valve unit 90 is controlled according to the first and the second control voltage Vref, Vdrv*.
    Type: Grant
    Filed: October 5, 2011
    Date of Patent: August 12, 2014
    Assignee: Hitachi Metals, Ltd.
    Inventors: Takao Goto, Toshihiro Aono, Tetsuroh Kawai
  • FLOW CONTROL DEVICE
    Publication number: 20120247584
    Abstract: In a flow control device 100, a comparator 40 outputs a first control voltage Vref based on a comparison of an instruction value signal Vi1 of the flow volume and a signal Vi2 according to the sensor output signal Vs. A feedback current generator 30 generates a feedback current Ifb according to a difference between the sensor output signal Vs and a signal Vi2 according to the instruction value signal Vi1. A feedback voltage generator 50 is a resister. A feed forward current generator 20 generates a feed forward current Iff according to the instruction value signal Vi1. A synthesis unit 60 generates a second control voltage Vdrv* obtained by adding to the feedback voltage Vfb a voltage according to a sum of the feedback current Ifb and the feed forward current Iff. The valve unit 90 is controlled according to the first and the second control voltage Vref, Vdrv*.
    Type: Application
    Filed: October 5, 2011
    Publication date: October 4, 2012
    Applicant: HITACHI METALS, LTD.
    Inventors: Takao GOTO, Toshihiro AONO, Tetsuroh KAWAI
  • Composite magnetic head including a slider plate and a back board
    Patent number: 5717543
    Abstract: A slider plate fixing a front magnetic core at a predetermined position is joined and fixed to a back board provided with a back yoke and a coil layer so that a transducer element is constituted by the front magnetic core, the back yoke, and the coil layer, whereby a composite magnetic head is formed.
    Type: Grant
    Filed: April 9, 1996
    Date of Patent: February 10, 1998
    Assignee: Hitachi Metals, Ltd.
    Inventors: Shinichi Ito, Ryo Goto, Tetsuroh Kawai, Kiyoshi Nakajima, Shuji Koike, Shuji Sudo