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).
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Publication number: 20210126718Abstract: 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: ApplicationFiled: October 20, 2020Publication date: April 29, 2021Applicant: FUJITSU LIMITEDInventors: Hiroyuki Tatsukawa, Hiroshi Yoshida, KOUICHI MAEDA
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Patent number: 9852099Abstract: 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: GrantFiled: May 14, 2015Date of Patent: December 26, 2017Assignee: DENSO CORPORATIONInventors: Toshiaki Iwasaki, Susumu Tsuruta, Kouichi Maeda
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Publication number: 20150331819Abstract: 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: ApplicationFiled: May 14, 2015Publication date: November 19, 2015Inventors: Toshiaki IWASAKI, Susumu TSURUTA, Kouichi MAEDA
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Patent number: 8712253Abstract: 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: GrantFiled: May 10, 2012Date of Patent: April 29, 2014Assignee: Fujitsu LimitedInventors: Kouichi Maeda, Tomoyuki Sakata
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Publication number: 20120294612Abstract: 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: ApplicationFiled: May 10, 2012Publication date: November 22, 2012Applicant: FUJITSU LIMITEDInventors: Kouichi MAEDA, Tomoyuki SAKATA
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Patent number: 8200090Abstract: 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: GrantFiled: September 16, 2009Date of Patent: June 12, 2012Assignee: Fujitsu LimitedInventors: Yuichiro Sakane, Ryuta Hoshi, Akira Yamamoto, Tsutomu Tsurumi, Yasushi Sugaya, Tomoyuki Sakata, Kouichi Maeda, Hiromu Yoshii
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Patent number: 8121490Abstract: 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: GrantFiled: March 11, 2008Date of Patent: February 21, 2012Assignee: Fujitsu LimitedInventors: Tomoyuki Sakata, Yoshikazu Nakanishi, Haruki Tanaka, Kouichi Maeda, Takeshi Noma
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Patent number: 7936845Abstract: 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: GrantFiled: October 11, 2007Date of Patent: May 3, 2011Assignee: Fujitsu LimitedInventors: Hiroshi Yoshida, Kouichi Maeda, Mamoru Suematsu
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Publication number: 20100067917Abstract: 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: ApplicationFiled: September 16, 2009Publication date: March 18, 2010Applicant: FUJITSU LIMITEDInventors: Yuichiro SAKANE, Ryuta Hoshi, Akira Yamamoto, Tsutomu Tsurumi, Yasushi Sugaya, Tomoyuki Sakata, Kouichi Maeda, Hiromu Yoshii
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Patent number: 7540479Abstract: 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: GrantFiled: February 20, 2007Date of Patent: June 2, 2009Assignee: Tokai Rubber Industries, Ltd.Inventors: Takehiro Okanaka, Kouichi Maeda, Tsutomu Matsuoka
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Publication number: 20080232806Abstract: 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: ApplicationFiled: March 11, 2008Publication date: September 25, 2008Applicant: FUJITSU LIMITEDInventors: Tomoyuki SAKATA, Yoshikazu Nakanishi, Haruki Tanaka, Kouichi Maeda, Takeshi Noma
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Publication number: 20080095219Abstract: 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: ApplicationFiled: October 11, 2007Publication date: April 24, 2008Applicant: FUJITSU LIMITEDInventors: Hiroshi Yoshida, Kouichi Maeda, Mamoru Suematsu
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Publication number: 20080018032Abstract: 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: ApplicationFiled: July 31, 2007Publication date: January 24, 2008Applicant: TOKAI RUBBER INDUSTRIES, LTD.Inventors: Yoshinori Yasumoto, Kouichi Maeda
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Publication number: 20070228624Abstract: 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: ApplicationFiled: February 20, 2007Publication date: October 4, 2007Applicant: Tokai Rubber Industries, Ltd.Inventors: Takehiro Okanaka, Kouichi Maeda, Tsutomu Matsuoka
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Patent number: 7267740Abstract: 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: GrantFiled: May 10, 2005Date of Patent: September 11, 2007Assignee: Tokai Rubber Industries, Ltd.Inventors: Yoshinori Yasumoto, Kouichi Maeda
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Patent number: 7128311Abstract: 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: GrantFiled: March 24, 2004Date of Patent: October 31, 2006Assignees: 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
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Patent number: 6994332Abstract: 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: GrantFiled: March 24, 2004Date of Patent: February 7, 2006Assignees: 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
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Publication number: 20050253317Abstract: 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: ApplicationFiled: May 10, 2005Publication date: November 17, 2005Applicant: TOKAI RUBBER INDUSTRIES, LTD.Inventors: Yoshinori Yasumoto, Kouichi Maeda
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Patent number: 6806747Abstract: 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: GrantFiled: December 20, 2002Date of Patent: October 19, 2004Assignee: Denso CorporationInventors: Yoshimitsu Honda, Kouichi Maeda, Yoshinori Yunosawa, Kouji Ichikawa
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Publication number: 20040188905Abstract: 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: ApplicationFiled: March 24, 2004Publication date: September 30, 2004Applicants: 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