Patents by Inventor Kouichi Maeda

Kouichi Maeda 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: 20210126718
    Abstract: A waveform correction apparatus includes a receiver configured to receive a first signal and a second signal from a signal transmission apparatus, the first signal being a PAM4 signal having a data pattern of a bit array in which gray coding is performed, and the second signal being a PAM4 signal having a data pattern of a bit array in which the gray coding is not performed, and a processor coupled to the receiver and configured to adjust a number of taps in an equalizer based on a difference between correct count values of forward error correction performed on the respective data patterns of the first signal and the second signal.
    Type: Application
    Filed: October 20, 2020
    Publication date: April 29, 2021
    Applicant: FUJITSU LIMITED
    Inventors: Hiroyuki Tatsukawa, Hiroshi Yoshida, KOUICHI MAEDA
  • Patent number: 9852099
    Abstract: A slave communication device is connected to a master communication device through a single bus, and transmits a data signal according to a synchronization signal transmitted from the master communication device. The slave communication device includes a current reduction unit that reduces a current flowing into the bus from the slave communication device at least in a period where the synchronization signal is transmitted from the master communication device.
    Type: Grant
    Filed: May 14, 2015
    Date of Patent: December 26, 2017
    Assignee: DENSO CORPORATION
    Inventors: Toshiaki Iwasaki, Susumu Tsuruta, Kouichi Maeda
  • Publication number: 20150331819
    Abstract: A slave communication device is connected to a master communication device through a single bus, and transmits a data signal according to a synchronization signal transmitted from the master communication device. The slave communication device includes a current reduction unit that reduces a current flowing into the bus from the slave communication device at least in a period where the synchronization signal is transmitted from the master communication device.
    Type: Application
    Filed: May 14, 2015
    Publication date: November 19, 2015
    Inventors: Toshiaki IWASAKI, Susumu TSURUTA, Kouichi MAEDA
  • Patent number: 8712253
    Abstract: An optical packet signal transmission device includes a transmitting unit which includes a plurality of data delay circuits; a plurality of optical branch units which branches some of the optical packet signals as monitor lights; an optical switch which selects one of the monitor lights; a test signal generation circuit which generates a test signal which is used to adjust a delay amount in the data delay circuits; a reference optical pulse generation circuit which generates a reference optical pulse based on the test signal; an optical phase comparator which detects an relative optical phase difference by comparing the phases of the selected monitor light and the reference optical pulse; and a control circuit which sequentially sends the test signals to the data delay circuits, switches the selected monitor light, detects a relative optical phase, determines the delay amount based on a detection result, and sets the delay amount.
    Type: Grant
    Filed: May 10, 2012
    Date of Patent: April 29, 2014
    Assignee: Fujitsu Limited
    Inventors: Kouichi Maeda, Tomoyuki Sakata
  • Publication number: 20120294612
    Abstract: An optical packet signal transmission device includes a transmitting unit which includes a plurality of data delay circuits; a plurality of optical branch units which branches some of the optical packet signals as monitor lights; an optical switch which selects one of the monitor lights; a test signal generation circuit which generates a test signal which is used to adjust a delay amount in the data delay circuits; a reference optical pulse generation circuit which generates a reference optical pulse based on the test signal; an optical phase comparator which detects an relative optical phase difference by comparing the phases of the selected monitor light and the reference optical pulse; and a control circuit which sequentially sends the test signals to the data delay circuits, switches the selected monitor light, detects a relative optical phase, determines the delay amount based on a detection result, and sets the delay amount.
    Type: Application
    Filed: May 10, 2012
    Publication date: November 22, 2012
    Applicant: FUJITSU LIMITED
    Inventors: Kouichi MAEDA, Tomoyuki SAKATA
  • Patent number: 8200090
    Abstract: An aspect of the embodiments utilizes an optical transmission apparatus which includes a rough adjustment execution portion that monitors a bit error rate of an optical signal for set values of a dispersion compensator where the set values have been set less closely to each other within a dispersion compensation control range than when a wavelength dispersion value set in the dispersion compensator is determined, and carries out a rough adjustment to determine a comparison threshold value used to set the wavelength dispersion value based on the monitored bit error rate, and a fine adjustment execution portion that monitors the bit error rate for the dispersion compensator the set values have been set more closely to each other, and carries out an adjustment to determine a wavelength dispersion value corresponding to the midpoint between the two acquired bit error rates as the wavelength dispersion value of the dispersion compensator.
    Type: Grant
    Filed: September 16, 2009
    Date of Patent: June 12, 2012
    Assignee: Fujitsu Limited
    Inventors: Yuichiro Sakane, Ryuta Hoshi, Akira Yamamoto, Tsutomu Tsurumi, Yasushi Sugaya, Tomoyuki Sakata, Kouichi Maeda, Hiromu Yoshii
  • Patent number: 8121490
    Abstract: A transponder includes a CDR section that extracts clocks from an input signal, an oscillating section that can output various frequencies to the CDR section, a frequency instruction processing section that instructs the oscillating section to output an arbitrary frequency, a detection processing section, and a frame processing section control section. The detection processing section determines whether the frequency output from the oscillating section and an input signal synchronize in frequency or not in response to an instruction by the frequency instruction processing section, and detects a synchronization frequency. The frame processing section control section operates a frame processing section based on the synchronization frequency detected by the detection processing section.
    Type: Grant
    Filed: March 11, 2008
    Date of Patent: February 21, 2012
    Assignee: Fujitsu Limited
    Inventors: Tomoyuki Sakata, Yoshikazu Nakanishi, Haruki Tanaka, Kouichi Maeda, Takeshi Noma
  • Patent number: 7936845
    Abstract: Equal-length group data obtained by grouping together slot pairs connected by a wiring pattern of equal length is stored in advance. Error rate is determined while changing a pre-emphasis (PE) setting value and an equalizer (EQ) setting value of a signal transmitted between a specified slot pair. The slot pairs belonging to the same equal-length group as the specified slot pair are selected based on the equal-length group data, and optimum PE and EQ setting values, determined based on the error rate, are set for the signals transmitted between the selected slot pairs.
    Type: Grant
    Filed: October 11, 2007
    Date of Patent: May 3, 2011
    Assignee: Fujitsu Limited
    Inventors: Hiroshi Yoshida, Kouichi Maeda, Mamoru Suematsu
  • Publication number: 20100067917
    Abstract: An aspect of the embodiments utilizes an optical transmission apparatus which includes a rough adjustment execution portion that monitors a bit error rate of an optical signal for set values of a dispersion compensator where the set values have been set less closely to each other within a dispersion compensation control range than when a wavelength dispersion value set in the dispersion compensator is determined, and carries out a rough adjustment to determine a comparison threshold value used to set the wavelength dispersion value based on the monitored bit error rate, and a fine adjustment execution portion that monitors the bit error rate for the dispersion compensator the set values have been set more closely to each other, and carries out an adjustment to determine a wavelength dispersion value corresponding to the midpoint between the two acquired bit error rates as the wavelength dispersion value of the dispersion compensator.
    Type: Application
    Filed: September 16, 2009
    Publication date: March 18, 2010
    Applicant: FUJITSU LIMITED
    Inventors: Yuichiro SAKANE, Ryuta Hoshi, Akira Yamamoto, Tsutomu Tsurumi, Yasushi Sugaya, Tomoyuki Sakata, Kouichi Maeda, Hiromu Yoshii
  • Patent number: 7540479
    Abstract: There is provided a vibration damping device including; a pair of rubber arm portions connecting an inner fitting and an outer fitting to each other in the horizontal direction; and a rubber leg portion connecting in the vertical direction; the paired rubber arm portions are formed so that the thickness thereof decreases gradually from the inner fitting side toward the outer fitting side, and the rubber leg portion is formed so that each of both side surfaces is formed by an inwardly depressed curved surface, and is formed into a curved broaden shape toward the outer fitting side. Thereby, a spring constant in the horizontal direction is increased advantageously while a spring constant in the vertical direction kept large, and the durability of the rubber elastic body can be increased effectively.
    Type: Grant
    Filed: February 20, 2007
    Date of Patent: June 2, 2009
    Assignee: Tokai Rubber Industries, Ltd.
    Inventors: Takehiro Okanaka, Kouichi Maeda, Tsutomu Matsuoka
  • Publication number: 20080232806
    Abstract: A transponder includes a CDR section that extracts clocks from an input signal, an oscillating section that can output various frequencies to the CDR section, a frequency instruction processing section that instructs the oscillating section to output an arbitrary frequency, a detection processing section, and a frame processing section control section. The detection processing section determines whether the frequency output from the oscillating section and an input signal synchronize in frequency or not in response to an instruction by the frequency instruction processing section, and detects a synchronization frequency. The frame processing section control section operates a frame processing section based on the synchronization frequency detected by the detection processing section.
    Type: Application
    Filed: March 11, 2008
    Publication date: September 25, 2008
    Applicant: FUJITSU LIMITED
    Inventors: Tomoyuki SAKATA, Yoshikazu Nakanishi, Haruki Tanaka, Kouichi Maeda, Takeshi Noma
  • Publication number: 20080095219
    Abstract: Equal-length group data obtained by grouping together slot pairs connected by a wiring pattern of equal length is stored in advance. Error rate is determined while changing a pre-emphasis (PE) setting value and an equalizer (EQ) setting value of a signal transmitted between a specified slot pair. The slot pairs belonging to the same equal-length group as the specified slot pair are selected based on the equal-length group data, and optimum PE and EQ setting values, determined based on the error rate, are set for the signals transmitted between the selected slot pairs.
    Type: Application
    Filed: October 11, 2007
    Publication date: April 24, 2008
    Applicant: FUJITSU LIMITED
    Inventors: Hiroshi Yoshida, Kouichi Maeda, Mamoru Suematsu
  • Publication number: 20080018032
    Abstract: A vehicle vibration-damping device including a rigid housing and an independent mass member housed in the housing and having a metallic mass of circular shape in section and a rubber elastic body layer adhered to the metallic mass. A distance of a gap between opposing surfaces of the housing and the metallic mass in the radial direction, with the housing and metallic mass disposed coaxially, is set to between 0.5 and 2 mm. The rubber elastic body layer is formed around an entire outer peripheral surface of the metallic mass by a vulcanization molding of a rubber material filling the gap, and thermal contraction is used both to cause the rubber elastic body layer to peel from the housing and to cause it to adhere onto the outer peripheral surface of the metallic mass to thereby fabricate a small gap of no more than 0.1 mm. A method of manufacturing the same is also disclosed.
    Type: Application
    Filed: July 31, 2007
    Publication date: January 24, 2008
    Applicant: TOKAI RUBBER INDUSTRIES, LTD.
    Inventors: Yoshinori Yasumoto, Kouichi Maeda
  • Publication number: 20070228624
    Abstract: There is provided a vibration damping device including; a pair of rubber arm portions connecting an inner fitting and an outer fitting to each other in the horizontal direction; and a rubber leg portion connecting in the vertical direction; the paired rubber arm portions are formed so that the thickness thereof decreases gradually from the inner fitting side toward the outer fitting side, and the rubber leg portion is formed so that each of both side surfaces is formed by an inwardly depressed curved surface, and is formed into a curved broaden shape toward the outer fitting side. Thereby, a spring constant in the horizontal direction is increased advantageously while a spring constant in the vertical direction kept large, and the durability of the rubber elastic body can be increased effectively.
    Type: Application
    Filed: February 20, 2007
    Publication date: October 4, 2007
    Applicant: Tokai Rubber Industries, Ltd.
    Inventors: Takehiro Okanaka, Kouichi Maeda, Tsutomu Matsuoka
  • Patent number: 7267740
    Abstract: A vehicle vibration-damping device including a rigid housing and an independent mass member housed in the housing and having a metallic mass of circular shape in section and a rubber elastic body layer adhered to the metallic mass. A distance of a gap between opposing surfaces of the housing and the metallic mass in the radial direction, with the housing and metallic mass disposed coaxially, is set to between 0.5 and 2 mm. The rubber elastic body layer is formed around an entire outer peripheral surface of the metallic mass by a vulcanization molding of a rubber material filling the gap, and thermal contraction is used both to cause the rubber elastic body layer to peel from the housing and to cause it to adhere onto the outer peripheral surface of the metallic mass to thereby fabricate a small gap of no more than 0.1 mm. A method of manufacturing the same is also disclosed.
    Type: Grant
    Filed: May 10, 2005
    Date of Patent: September 11, 2007
    Assignee: Tokai Rubber Industries, Ltd.
    Inventors: Yoshinori Yasumoto, Kouichi Maeda
  • Patent number: 7128311
    Abstract: A vibration damping actuator including: a cup-shaped housing; an output member disposed spaced apart from an opening end of the housing; a guide rod disposed on the output member and positioned inserted into a guide hole; a coil member provided to one of the housing and the output member; an armature disposed on an other of the housing and the output member, the armature being adapted to exert actuating force on the output member; an annular fixing member arranged about the output member; a support rubber plate disposed between the annular fixing member and the output member; and a positioning projection formed at an inside peripheral edge of the fixing member by projecting the inside peripheral edge of the fixing member in cylindrical configuration in an axial direction towards an inside of the housing. The positioning projection is disposed at a location situated inward by a predetermined distance from the opening of the housing for positioning the fixing member relative to the housing.
    Type: Grant
    Filed: March 24, 2004
    Date of Patent: October 31, 2006
    Assignees: Tokai Rubber Industries, Ltd., Honda Motor Co., Ltd.
    Inventors: Katsuhiro Goto, Hajime Maeno, Kazuhiko Kato, Kei Okumura, Kouichi Maeda, Tetsuo Mikasa, Hirotomi Nemoto, Hiroaki Ue, Ken Iinuma
  • Patent number: 6994332
    Abstract: A vibration damping actuator including: a guide hole open onto a bottom face of a housing; a lid metal plate fitted into the opening of the guide hole with a size enough to hinder inward displacement thereof into the guide hole by an annular shoulder portion; an engaging groove disposed on an inner circumferential surface of the opening; a snap ring of C-letter shape fitted into the engaging groove to prevent the lid metal plate from becoming dislodged from the opening; and a sealing rubber layer formed covering an inside face of the lid metal plate. The lid metal plate is pressed by the snap ring so that the sealing rubber layer is pushed against the annular shoulder portion, thereby sealing the opening of the guide hole.
    Type: Grant
    Filed: March 24, 2004
    Date of Patent: February 7, 2006
    Assignees: Tokai Rubber Industries, Ltd., Honda Motor Co., Ltd.
    Inventors: Katsuhiro Goto, Hajime Maeno, Kei Okumura, Kazuhiko Kato, Kouichi Maeda, Tetsuo Mikasa, Hirotomi Nemoto, Hiroaki Ue, Ken Iinuma
  • Publication number: 20050253317
    Abstract: A vehicle vibration-damping device including a rigid housing and an independent mass member housed in the housing and having a metallic mass of circular shape in section and a rubber elastic body layer adhered to the metallic mass. A distance of a gap between opposing surfaces of the housing and the metallic mass in the radial direction, with the housing and metallic mass disposed coaxially, is set to between 0.5 and 2 mm. The rubber elastic body layer is formed around an entire outer peripheral surface of the metallic mass by a vulcanization molding of a rubber material filling the gap, and thermal contraction is used both to cause the rubber elastic body layer to peel from the housing and to cause it to adhere onto the outer peripheral surface of the metallic mass to thereby fabricate a small gap of no more than 0.1 mm. A method of manufacturing the same is also disclosed.
    Type: Application
    Filed: May 10, 2005
    Publication date: November 17, 2005
    Applicant: TOKAI RUBBER INDUSTRIES, LTD.
    Inventors: Yoshinori Yasumoto, Kouichi Maeda
  • Patent number: 6806747
    Abstract: When a control power source voltage becomes lower than an operation guarantee voltage level, the output of a start-up circuit assumes an H-level, a NOR gate produces an output shut-off signal of an L-level, and FETs are turned off. As the control power source voltage further decreases, the output shut-off control circuit loses stability in the operation. In this case, a resistor maintains the FETs in the OFF state due to its pull-down operation. As a result, the output of the output circuit is maintained in a high-impedance state over the whole range of control power source voltages lower than the operation guarantee voltage level.
    Type: Grant
    Filed: December 20, 2002
    Date of Patent: October 19, 2004
    Assignee: Denso Corporation
    Inventors: Yoshimitsu Honda, Kouichi Maeda, Yoshinori Yunosawa, Kouji Ichikawa
  • Publication number: 20040188905
    Abstract: A vibration damping actuator including: a cup-shaped housing; an output member disposed spaced apart from an opening end of the housing; a guide rod disposed on the output member and positioned inserted into a guide hole; a coil member provided to one of the housing and the output member; an armature disposed on an other of the housing and the output member, the armature being adapted to exert actuating force on the output member; an annular fixing member arranged about the output member; a support rubber plate disposed between the annular fixing member and the output member; and a positioning projection formed at an inside peripheral edge of the fixing member by projecting the inside peripheral edge of the fixing member in cylindrical configuration in an axial direction towards an inside of the housing. The positioning projection is disposed at a location situated inward by a predetermined distance from the opening of the housing for positioning the fixing member relative to the housing.
    Type: Application
    Filed: March 24, 2004
    Publication date: September 30, 2004
    Applicants: TOKAI RUBBER INDUSTRIES, LTD., HONDA MOTOR CO., LTD.
    Inventors: Katsuhiro Goto, Hajime Maeno, Kazuhiko Kato, Kei Okumura, Kouichi Maeda, Tetsuo Mikasa, Hirotomi Nemoto, Hiroaki Ue, Ken IInuma