Patents by Inventor Masayoshi Ohkawa

Masayoshi Ohkawa 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: 6516509
    Abstract: A method for manufacturing a component provided with a number of liquid paths having movable members for use of liquid discharging comprises the steps of displacing the movable members provided for thin film material by use of such thin film material having the movable members on it, and a component provided with a plurality of recessed portions, and of placing the movable members, which are in the state of being displaced with respect to the recessed portions of the component correspondingly, hence making it possible to fabricate a liquid jet head without damaging or deforming such thin film material constituting the movable members. With the provision of the movable members, the discharging power and efficiency of the liquid jet head are significantly enhanced to obtain recorded images of high quality at higher speeds.
    Type: Grant
    Filed: June 6, 1997
    Date of Patent: February 11, 2003
    Assignee: Canon Kabushiki Kaisha
    Inventors: Takayuki Ono, Koji Yamakawa, Tsuyoshi Orikasa, Toshio Kashino, Hiroyuki Kigami, Kimiyuki Hayasaki, Hisashi Fukai, Kiyomitsu Kudo, Yoshie Asakawa, Masayoshi Ohkawa
  • Patent number: 6349239
    Abstract: A method for manufacturing a liquid jet recording head comprises of the steps of calculating the difference between the distance B from the first heater on the element substrate to the cut face of the element substrate and the distance A from the first flow path groove on the ceiling plate to the abutment reference of the ceiling plate, measuring the amounts of deviation in the positional precisions in the state where the element substrates and the ceiling plates are actually positioned, working out a correction value from the distributional condition of such deviations, feeding back the correction value for determining the corrected amount of retraction. Then, after the abutment reference of the ceiling plate is allowed to abut upon the cut face of the element substrate by means of a push jig, retraction is performed by moving the ceiling plate by means of a retraction jig in the reverse direction with respect to the element substrate, hence positioning the ceiling plate and the element substrate.
    Type: Grant
    Filed: March 12, 1998
    Date of Patent: February 19, 2002
    Assignee: Canon Kabushiki Kaisha
    Inventors: Tsuyoshi Orikasa, Koji Yamakawa, Hiroyuki Kigami, Kimiyuki Hayasaki, Hisashi Fukai, Takayuki Ono, Masayoshi Ohkawa
  • Publication number: 20010051838
    Abstract: A method for manufacturing a liquid jet recording head comprises of the steps of calculating the difference between the distance B from the first heater on the element substrate to the cut face of the element substrate and the distance A from the first flow path groove on the ceiling plate to the abutment reference of the ceiling plate, measuring the amounts of deviation in the positional precisions in the state where the element substrates and the ceiling plates are actually positioned, working out a correction value from the distributional condition of such deviations, feeding back the correction value for determining the corrected amount of retraction. Then, after the abutment reference of the ceiling plate is allowed to abut upon the cut face of the element substrate by means of a push jig, retraction is performed by moving the ceiling plate by means of a retraction jig in the reverse direction with respect to the element substrate, hence positioning the ceiling plate and the element substrate.
    Type: Application
    Filed: March 12, 1998
    Publication date: December 13, 2001
    Inventors: TSUYOSHI ORIKASA, KOJI YAMAKAWA, HIROYUKI KIGAMI, KIMIYUKI HAYASAKI, HISASHI FUKAI, TAKAYUKI ONO, MASAYOSHI OHKAWA
  • Patent number: 6325482
    Abstract: An apparatus and method for accurately and rapidly correcting a printing characteristic of a printhead, a printhead whose printing characteristic is corrected by the above apparatus, and a printing apparatus using the printhead. In the apparatus for correcting the printing characteristic of the printhead, n kinds of printing control signal patterns are used to a full line printhead, printing patterns are experimentally printed in response to the printing control signal patterns on a printing medium and a reference density distribution is generated from one of n kinds of the printing patterns printed. Then, one of the n kinds of printing control signal patterns is selected for each of a plurality of printing elements such that a density value on each pixel is equal or close to the reference density distribution.
    Type: Grant
    Filed: September 8, 1999
    Date of Patent: December 4, 2001
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kimiyuki Hayasaki, Koji Yamakawa, Yutaka Koizumi, Tsuyoshi Orikasa, Hiroyuki Kigami, Hisashi Fukai, Takayuki Ono, Masayoshi Ohkawa
  • Patent number: 6260958
    Abstract: A liquid ejection head includes an ejection outlet for ejecting liquid; a plurality of liquid flow paths; a bubble generating region for generating a bubble; a movable member disposed faced to the bubble generating region and movable between a first position and a second position which is farther from the bubble generating region than the first position; wherein the movable member moves from the first position to the second position by pressure produced by the generation of the bubble to permit expansion of the bubble more in a downstream side closer to the ejection outlet than in an upstream side. In addition, a first common liquid chamber having a height, measured in a direction perpendicular to a plane including the movable member at rest, which is larger than that of the liquid flow paths, wherein the movable member has a fulcrum in the first common liquid chamber and a free end in the liquid flow paths.
    Type: Grant
    Filed: July 14, 2000
    Date of Patent: July 17, 2001
    Assignee: Canon Kabushiki Kaisha
    Inventors: Aya Yoshihira, Kouji Yamakawa, Tsuyoshi Orikasa, Hiroyuki Ishinaga, Toshio Kashino, Hiroyuki Kigami, Kimiyuki Hayasaki, Hisashi Fukai, Kiyomitsu Kudo, Takayuki Ono, Yoshie Asakawa, Masayoshi Ohkawa
  • Patent number: 6169692
    Abstract: A memory cell having a floating gate is formed on a semiconductor substrate of a first conduction type and is disposed in a region having a deep well of a second conduction type formed to a semiconductor substrate and a shallow well of a first conduction type formed in the deep well. An erasing operation of emitting electrons from floating gates is conducted utilizing a tunneling phenomenon by setting a control gate terminal to ground voltage and a source terminal S to VPP. The deep and shallow wells are supplied with VCC at time t1 and a source terminal is supplied with VPP at time t2 after a predetermined period of time from time t1 has elapsed.
    Type: Grant
    Filed: May 29, 1998
    Date of Patent: January 2, 2001
    Assignee: NEC Corporation
    Inventor: Masayoshi Ohkawa
  • Patent number: 6168264
    Abstract: A manufacturing method for a liquid ejecting unit having a comb-like separation wall, a displaceable member and a grooved member mating with the comb-like separation wall includes engaging the separation wall with the grooved member while being positioned by an abutment reference.
    Type: Grant
    Filed: June 9, 1997
    Date of Patent: January 2, 2001
    Assignee: Canon Kabushiki Kaisha
    Inventors: Aya Yoshihira, Kouji Yamakawa, Tsuyoshi Orikasa, Hiroyuki Ishinaga, Toshio Kashino, Hiroyuki Kigami, Kimiyuki Hayasaki, Hisashi Fukai, Kiyomitsu Kudo, Takayuki Ono, Yoshie Asakawa, Masayoshi Ohkawa
  • Patent number: 6008690
    Abstract: The present invention relates to a booster circuit which uses multiple pump circuits to provide high voltages. The pump circuits are provided with an input voltage Vcc and are generally each made up of a diode and a capacitor. A node driving circuit provides driving signals to driving nodes and thereby to the pump circuits. The driving nodes are connected by a charge transfer switch which is selectively activated so as to allow charge that would otherwise be lost to ground to be conserved for inclusion in the final high-output voltage.
    Type: Grant
    Filed: June 10, 1998
    Date of Patent: December 28, 1999
    Assignee: NEC Corporation
    Inventors: Toshio Takeshima, Masayoshi Ohkawa, Hiroshi Sugawara, Noaki Sudo
  • Patent number: 5894436
    Abstract: A variation in threshold of a memory cell is detected at a higher speed. A multi-valued nonvolatile semiconductor memory has a nonvolatile memory cell 41 for storing n-values (n.gtoreq.3) of data as thresholds in one cell, a reference signal generator 44 for emitting a reference signal group Vri (i.ltoreq.(n-1)), a reference signal group VriH(=Vri+.DELTA.V) and a reference signal group VriL(=Vri-.DELTA.
    Type: Grant
    Filed: October 29, 1997
    Date of Patent: April 13, 1999
    Assignee: NEC Corporation
    Inventors: Masayoshi Ohkawa, Toshio Takeshima
  • Patent number: 5334863
    Abstract: In an SRAM having TFT type memory cells, a pair of driver transistors and a pair of access transistors formed of N-channel MOS transistors on a silicon substrate are respectively arranged at positions point symmetric with respect to the center of gravity of the memory cell, and a pair of load transistors formed of P-channel type TFTs is also arranged in point symmetric positions with respect to the center of gravity. The gate electrodes of these N-channel MOS transistors and a word line are formed of a first layer of conductor film, a grounding wiring within the memory cell is formed of a second layer of conductor film, and TFTs are formed of a third and a fourth layers of conductor films. Two connecting holes for the digit lines and the drain regions of the access transistors are also arranged distributed point symmetric with respect to the center of gravity.
    Type: Grant
    Filed: June 8, 1992
    Date of Patent: August 2, 1994
    Assignee: NEC Corporation
    Inventors: Masayoshi Ohkawa, Fumihiko Hayashi
  • Patent number: 4680488
    Abstract: An improved driving circuit which can drive a large load at a high speed. The circuit comprises an input inverter receiving an input signal, a first buffer circuit, a capacitive feedback element coupled between an output of the first buffer circuit and the input inverter, and a second buffer circuit having an input terminal coupled to the output of the input buffer and an output terminal coupled to an input of the first buffer circuit.
    Type: Grant
    Filed: June 15, 1984
    Date of Patent: July 14, 1987
    Assignee: NEC Corporation
    Inventors: Koichiro Okumura, Masayoshi Ohkawa