Patents by Inventor Keiji Tanaka

Keiji Tanaka 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: 10302566
    Abstract: A method evaluates the mobility of a polymer composition in a high-temperature region of 150° C. or above. The method for evaluating a physical property of a polymer composition, the method comprising the steps of: obtaining a thin film sample which is formed on a substrate and which comprises: a fluorescent probe including a fluorescent rare earth complex having a melting point of 200° C. or higher; and a target polymer composition; and obtaining a relationship between a temperature and a fluorescent characteristic of the thin film.
    Type: Grant
    Filed: May 8, 2015
    Date of Patent: May 28, 2019
    Assignees: Kyushu University, Fuji Electric Co., Ltd.
    Inventors: Keiji Tanaka, Daisuke Kawaguchi, Atsuomi Shundo, Mika Aoki, Tatsuya Ganbe, Nobuyuki Sekine, Kenji Okamoto
  • Publication number: 20180351325
    Abstract: A driver circuit configured to increase or decrease a drive current flowing to a light emitting element in accordance with an input signal, the driver circuit including: an output terminal configured to be electrically connected between a bias current source and the light emitting element, and configured to draw an output current inward; a shunt circuit configured to generate a first current in accordance with the input signal; and a waveform shaping circuit configured to detect a rising transition of a voltage of the output terminal and generate a second current based at least in part on a result of detection, wherein the first current and the second current constitute the output current, wherein the first current increses when the input signal increases, and decreases when the input signal decreases, and wherein the voltage of the output terminal rises when the output current decreases.
    Type: Application
    Filed: May 30, 2018
    Publication date: December 6, 2018
    Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventor: Keiji TANAKA
  • Publication number: 20180327560
    Abstract: Provided is a method of producing a polymer-impregnated base resin which is excellent in providing low adsorption of proteins and blood cells such as platelets. The method of producing a polymer-impregnated base resin includes impregnating a base resin with a polymer solution that includes a solvent able to swell the base resin.
    Type: Application
    Filed: April 16, 2018
    Publication date: November 15, 2018
    Applicants: SUMITOMO RUBBER INDUSTRIES, LTD., KYUSHU UNIVERSITY, NATIONAL UNIVERSITY CORPORATION
    Inventors: Yasuhisa MINAGAWA, Keiji TANAKA, Hisao MATSUNO, Toyoaki HIRATA
  • Publication number: 20180295901
    Abstract: The present invention relates to an air cooling blower and a piece of air-cooled clothing on which the air cooling blower is mounted. An air intake port is provided on a first end side of a tubular fan case, and an air outlet is provided on a second end side. First lock portions are provided in portions of a mounting flange or in portions of the tubular fan case near the portions of the mounting flange, and a second lock portion is provided in a portion of the mounting flange that opposes the first lock portions via a central axis of the tubular fan case interposed therebetween or in a portion of the tubular fan case near the portion of the mounting flange that opposes the first lock portions via the central axis of the tubular fan case interposed therebetween.
    Type: Application
    Filed: June 19, 2017
    Publication date: October 18, 2018
    Applicant: SUN-S Co., Ltd.
    Inventors: Kaoru KITTAKA, Keiji TANAKA, Tsuyoshi NAKAMURA
  • Publication number: 20180275434
    Abstract: An optical modulator implementing an electro-absorption (EA) modulator is disclosed. The optical modulator includes a transmission line, a terminator, an EA modulator, a bonding wire, and a coil element. The transmission line transmits an electrical signal. The terminator terminates the transmission line. The coil element includes first and second inductors magnetically coupled with each other, where the first inductor is connected with the transmission line, while, the second inductor is connected with the terminator. The boding wire connects the first and second inductors with the EA modulator. Impedance of the coil element viewing from the transmission line substantially matches with impedance of the terminator.
    Type: Application
    Filed: March 20, 2018
    Publication date: September 27, 2018
    Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventor: Keiji TANAKA
  • Publication number: 20180267052
    Abstract: An object of the present invention is to provide a method for efficiently identifying a polyubiquitinated substrate which is generally not easily identified. The method for identifying a polyubiquitinated substrate includes (1) a step of expressing a trypsin-resistant polyubiquitin chain-binding protein and a ubiquitin ligase in a cell, (2) a step of isolating a complex that contains the trypsin-resistant polyubiquitin chain-binding protein from the cell having undergone the step (1), (3) a step of subjecting the complex isolated by the step (2) to trypsin digestion, and (4) a step of identifying a peptide that has a ubiquitination site from a digested material obtained by the step (3).
    Type: Application
    Filed: November 13, 2014
    Publication date: September 20, 2018
    Inventors: Yukiko Yoshida, Yasushi Saeki, Hikaru Tsuchiya, Arisa Murakami, Keiji Tanaka
  • Patent number: 9973165
    Abstract: A driver that drives an optical device, such as laser diode (LD) and/or optical modulator, is disclosed. The driver includes a variable gain amplifier (VGA) and a post amplifier. The post amplifier amplifies an output of the VGA to a preset amplifier as varying the gain of the VGA. The VGA includes two differential pairs each amplify the input signal oppositely in phases thereof and outputs of the differential pairs are compositely provided to the post amplifier. The gain of the VGA is varied by adjusting contribution of the second differential pair to the output of the VGA.
    Type: Grant
    Filed: October 19, 2016
    Date of Patent: May 15, 2018
    Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventor: Keiji Tanaka
  • Patent number: 9891228
    Abstract: Protein ubiquitylation, an essential post-translational modification, regulates almost every cellular process including protein degradation, protein trafficking, signal transduction, and DNA damage response in eukaryotic cells. The diverse functions of ubiquitylation are thought to be mediated by distinct chain topologies resulting from eight different ubiquitin linkages, chain lengths, and complexities. Currently, ubiquitin linkages are generally thought to be a critical determinant of ubiquitin signaling. However, ubiquitin chain lengths, another key element of ubiquitin signaling, have not been well documented especially in vivo situation during past three decades from the discovery of ubiquitin. The reason of this was simply because no method has been available for determination of ubiquitin chain length in endogenous ubiquitylated substrates. In the present invention, a practical technique for determining the actual length of substrate-attached polyubiquitin chains from biological samples is established.
    Type: Grant
    Filed: November 5, 2014
    Date of Patent: February 13, 2018
    Assignee: Tokyo Metropolitan Institute of Medical Science
    Inventors: Yasushi Saeki, Hikaru Tsuchiya, Ai Kaiho, Keiji Tanaka
  • Patent number: 9891229
    Abstract: Protein ubiquitylation, an essential post-translational modification, regulates almost every cellular process including protein degradation, protein trafficking, signal transduction, and DNA damage response in eukaryotic cells. The diverse functions of ubiquitylation are thought to be mediated by distinct chain topologies resulting from eight different ubiquitin linkages, chain lengths, and complexities. Currently, ubiquitin linkages are generally thought to be a critical determinant of ubiquitin signaling. However, ubiquitin chain lengths, another key element of ubiquitin signaling, have not been well documented especially in vivo situation during past three decades from the discovery of ubiquitin. The reason of this was simply because no method has been available for determination of ubiquitin chain length in endogenous ubiquitylated substrates. In the present invention, a practical technique for determining the actual length of substrate-attached polyubiquitin chains from biological samples is established.
    Type: Grant
    Filed: September 21, 2017
    Date of Patent: February 13, 2018
    Assignee: Tokyo Metropolitan Institute of Medical Science
    Inventors: Yasushi Saeki, Hikaru Tsuchiya, Ai Kaiho, Keiji Tanaka
  • Publication number: 20180017571
    Abstract: Protein ubiquitylation, an essential post-translational modification, regulates almost every cellular process including protein degradation, protein trafficking, signal transduction, and DNA damage response in eukaryotic cells. The diverse functions of ubiquitylation are thought to be mediated by distinct chain topologies resulting from eight different ubiquitin linkages, chain lengths, and complexities. Currently, ubiquitin linkages are generally thought to be a critical determinant of ubiquitin signaling. However, ubiquitin chain lengths, another key element of ubiquitin signaling, have not been well documented especially in vivo situation during past three decades from the discovery of ubiquitin. The reason of this was simply because no method has been available for determination of ubiquitin chain length in endogenous ubiquitylated substrates. In the present invention, a practical technique for determining the actual length of substrate-attached polyubiquitin chains from biological samples is established.
    Type: Application
    Filed: September 21, 2017
    Publication date: January 18, 2018
    Inventors: Yasushi Saeki, Hikaru Tsuchiya, Ai Kaiho, Keiji Tanaka
  • Patent number: 9825602
    Abstract: An amplifier including a pre-amplifier, an impedance converter, and a traveling wave amplifier (TWA) is disclosed. The pre-amplifier receives a differential input signal and has a pair of first output nodes that output a first differential signal by amplifying the differential input signal. Each first output node has first output impedance. The impedance converter includes a pair of first input nodes that receive the first differential signal and a pair of second output nodes that output a second differential signal. Each first input node has first input impedance greater than the first output impedance. The impedance converter converts the first differential signal into the second differential signal. Each second output node has second output impedance smaller than the first output impedance. The TWA includes a pair of transmission lines connected to the pair of the second output nodes. Each transmission line has characteristic impedance matching with the second output impedance.
    Type: Grant
    Filed: October 20, 2016
    Date of Patent: November 21, 2017
    Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Naoki Itabashi, Keiji Tanaka
  • Patent number: 9705601
    Abstract: A pulse amplitude modulation (PAM) signal generator is disclosed. The PAM signal generator, which is applicable to a vertical cavity surface emitting laser diode (VCSEL), provides a plurality of differential units each having two outputs complementary to each other and biased by a power supply voltage through the commonly connected VCSEL and a dummy diode. The differential units have respective current sources each, where partial sums and a total sum of the currents correspond to the multiple output levels of the VCSEL. The PAM signal generator also provides compensating units to compensate the saturation (non-linearity) of the optical output of the VCSEL.
    Type: Grant
    Filed: November 25, 2015
    Date of Patent: July 11, 2017
    Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventor: Keiji Tanaka
  • Patent number: 9660601
    Abstract: An amplifier includes a differential amplifier and a compensator. A differential amplifier includes a current source and paired transistors. The paired transistors generate an output signal by dividing a source current supplied by the current source into emitter currents of the paired transistors in response to a difference between an input signal and a reference signal. A compensator includes an amplifying transistor and a feedback circuit that feeds a collector current output from a collector of the amplifying transistor back to a base of the amplifying transistor therethrough. The compensator generates the reference signal at a base of the amplifying transistor. The compensator decreases power consumption of the amplifying transistor when the collector current increases, and increases the power consumption of the amplifying transistor when the collector current decreases. The compensator suppresses a peaking of gain in a low frequency band.
    Type: Grant
    Filed: April 22, 2016
    Date of Patent: May 23, 2017
    Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Keiji Tanaka, Yoshiyuki Sugimoto
  • Publication number: 20170117860
    Abstract: An amplifier including a pre-amplifier, an impedance converter, and a traveling wave amplifier (TWA) is disclosed. The pre-amplifier receives a differential input signal and has a pair of first output nodes that output a first differential signal by amplifying the differential input signal. Each first output node has first output impedance. The impedance converter includes a pair of first input nodes that receive the first differential signal and a pair of second output nodes that output a second differential signal. Each first input node has first input impedance greater than the first output impedance. The impedance converter converts the first differential signal into the second differential signal. Each second output node has second output impedance smaller than the first output impedance. The TWA includes a pair of transmission lines connected to the pair of the second output nodes. Each transmission line has characteristic impedance matching with the second output impedance.
    Type: Application
    Filed: October 20, 2016
    Publication date: April 27, 2017
    Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Naoki ITABASHI, Keiji TANAKA
  • Publication number: 20170117863
    Abstract: A driver that drives an optical device, such as laser diode (LD) and/or optical modulator, is disclosed. The driver includes a variable gain amplifier (VGA) and a post amplifier. The post amplifier amplifies an output of the VGA to a preset amplifier as varying the gain of the VGA. The VGA includes two differential pairs each amplify the input signal oppositely in phases thereof and outputs of the differential pairs are compositely provided to the post amplifier. The gain of the VGA is varied by adjusting contribution of the second differential pair to the output of the VGA.
    Type: Application
    Filed: October 19, 2016
    Publication date: April 27, 2017
    Inventor: Keiji TANAKA
  • Patent number: 9608405
    Abstract: The laser driver including a difference amplifier, a target potential circuit, an adjusting circuit, and bypass circuit is disclosed. The differential amplifier outputs a driving signal and a reverse driving signal having a phase opposite to a phase of the driving signal. The bypass circuit outputs an output current in response to the driving signal for generating a driving current for a semiconductor laser element that emits an optical signal in response to the driving signal. The adjusting circuit controls average potential of the driving signal and the reverse driving signal, so that the average potential becomes substantially equal to a target potential provided by the target potential circuit. The target potential corresponds to average optical power of the optical signal. When amplitude of the driving signal is changed for adjusting an extinction ratio of the optical signal, the adjusting circuit maintains the average optical power in a constant value.
    Type: Grant
    Filed: June 28, 2016
    Date of Patent: March 28, 2017
    Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventor: Keiji Tanaka
  • Patent number: 9608581
    Abstract: A differential amplifier includes an amplifying stage that outputs an output signal by amplifying an input signal with a gain set by a control signal, and an adjusting stage that stabilizes a DC level of the output signal. The amplifying stage includes a first source supplying a first current, and a load, and determines a ratio of a current flowing through the load to the first current depending on the input signal and the control signal, and generates the output signal from a voltage drop of the load. The adjusting stage includes a second source supplying a second current, and a monitor resistor, and generates a monitor current divided from the second current by the ratio, and duplicates the DC level as a voltage drop of the monitor resistor caused by the monitor current, and controls the first current source and the second current source depending on the DC level.
    Type: Grant
    Filed: March 24, 2016
    Date of Patent: March 28, 2017
    Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Naoki Itabashi, Taizo Tatsumi, Keiji Tanaka
  • Publication number: 20170025816
    Abstract: A laser driver includes a differential amplifier and a driver. The differential amplifier includes a first series circuit and a second series circuit each including a resistor, a transistor, and a current source that are connected in series to each other, a variable resistor connected between emitters of the transistors, and a variable capacitance element connected in parallel to the variable resistor. The differential amplifier generates a driving signal having amplitude proportional to amplitude of a differential signal externally input to the transistors. The driver generates a driving current in response to the driving signal for driving the semiconductor laser connected in series to the driver. The laser driver changes frequency characteristics of the differential amplifier by adjusting the variable resistor and the variable capacitance element to correct frequency characteristics of the semiconductor laser.
    Type: Application
    Filed: July 12, 2016
    Publication date: January 26, 2017
    Inventor: Keiji TANAKA
  • Publication number: 20170012406
    Abstract: The laser driver including a difference amplifier, a target potential circuit, an adjusting circuit, and bypass circuit is disclosed. The differential amplifier outputs a driving signal and a reverse driving signal having a phase opposite to a phase of the driving signal. The bypass circuit outputs an output current in response to the driving signal for generating a driving current for a semiconductor laser element that emits an optical signal in response to the driving signal. The adjusting circuit controls average potential of the driving signal and the reverse driving signal, so that the average potential becomes substantially equal to a target potential provided by the target potential circuit. The target potential corresponds to average optical power of the optical signal. When amplitude of the driving signal is changed for adjusting an extinction ratio of the optical signal, the adjusting circuit maintains the average optical power in a constant value.
    Type: Application
    Filed: June 28, 2016
    Publication date: January 12, 2017
    Inventor: Keiji TANAKA
  • Patent number: 9543906
    Abstract: An optical receiver with an expanded dynamic range for an input current is disclosed. The optical receiver includes a photodiode to generate a photocurrent, a trans-impedance amplifier (TIA) to convert the photocurrent into a voltage signal, a dummy TIA with a same arrangement as that of the TIA to generate a reference, a differential amplifier to amplify a difference between the voltage signal and the reference, a current source to extract a portion of the photocurrent, and a level detector to detect an average photocurrent and adjust the reference based on the average photocurrent.
    Type: Grant
    Filed: September 26, 2014
    Date of Patent: January 10, 2017
    Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventor: Keiji Tanaka