Patents by Inventor Yasushi Hayakawa

Yasushi Hayakawa 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: 12136797
    Abstract: The upper surface of the semiconductor substrate has a slope descending from the projection in the second direction at an angle of 0-12° to a horizontal plane. The mesa stripe structure has an inclined surface with a slope ascending from the upper surface of the semiconductor substrate at an angle of 45-55° to the horizontal plane, the mesa stripe structure having an upright surface rising from the inclined surface at an angle of 85-95° to the horizontal plane. The buried layer is made from semiconductor with ruthenium doped therein and is in contact with the inclined surface and the upright surface. The inclined surface is as high as 80% or less of height from the upper surface of the semiconductor substrate to a lower surface of the quantum well layer and is as high as 0.3 ?m or more.
    Type: Grant
    Filed: September 17, 2021
    Date of Patent: November 5, 2024
    Assignee: Lumentum Operations LLC
    Inventors: Takafumi Taniguchi, Shigenori Hayakawa, Yasushi Sakuma
  • Patent number: 8175205
    Abstract: A phase comparison circuit detects a phase difference between a data signal and the output from a variable delay circuit. A Code Operator detects a value of a control code corresponding to a delay equal to one period of an output clock. Then, when a delay amount of the variable delay circuit exceeds one period of a clock during synchronization of the output clock with the data signal while the control code is changed in accordance with the detection result by the phase delay circuit, a control code corresponding to a delay equal to one period of the output clock is added or subtracted to/from the control code at a time. Therefore, even if there is a difference in frequency between a data signal and a clock, it becomes possible to synchronize the data signal and the clock with application of the same clock phase.
    Type: Grant
    Filed: September 16, 2010
    Date of Patent: May 8, 2012
    Assignee: Renesas Electronics Corporation
    Inventors: Masashi Ishii, Takanori Hirota, Atsuhiko Ishibashi, Yasushi Hayakawa, Takeshi Oshita, Yoshiyuki Ota
  • Publication number: 20110007855
    Abstract: A phase comparison circuit detects a phase difference between a data signal and the output from a variable delay circuit. A Code Operator detects a value of a control code corresponding to a delay equal to one period of an output clock. Then, when a delay amount of the variable delay circuit exceeds one period of a clock during synchronization of the output clock with the data signal while the control code is changed in accordance with the detection result by the phase delay circuit, a control code corresponding to a delay equal to one period of the output clock is added or subtracted to/from the control code at a time. Therefore, even if there is a difference in frequency between a data signal and a clock, it becomes possible to synchronize the data signal and the clock with application of the same clock phase.
    Type: Application
    Filed: September 16, 2010
    Publication date: January 13, 2011
    Applicant: RENESAS ELECTRONICS CORPORATION
    Inventors: Masashi Ishii, Takanori Hirota, Atsuhiko Ishibashi, Yasushi Hayakawa, Takeshi Oshita, Yoshiyuki Ota
  • Patent number: 7822158
    Abstract: A phase comparison circuit detects a phase difference between a data signal and the output from a variable delay circuit. A Code Operator detects a value of a control code corresponding to a delay equal to one period of an output clock. Then, when a delay amount of the variable delay circuit exceeds one period of a clock during synchronization of the output clock with the data signal while the control code is changed in accordance with the detection result by the phase delay circuit, a control code corresponding to a delay equal to one period of the output clock is added or subtracted to/from the control code at a time. Therefore, even if there is a difference in frequency between a data signal and a clock, it becomes possible to synchronize the data signal and the clock with application of the same clock phase.
    Type: Grant
    Filed: June 30, 2006
    Date of Patent: October 26, 2010
    Assignee: Renesas Electronics Corporation
    Inventors: Masashi Ishii, Takanori Hirota, Atsuhiko Ishibashi, Yasushi Hayakawa, Takeshi Oshita, Yoshiyuki Ota
  • Publication number: 20070257316
    Abstract: A terminating resistance element of an LSI chip has an N? type impurity diffusion region formed at the surface of a P type well at the surface of a semiconductor substrate, an N+ type impurity diffusion layer formed at the surface of the N? type impurity diffusion region, and a pair of electrodes formed at respective ends at the surface of the N+ type impurity diffusion layer. The N? type impurity diffusion region has an impurity concentration lower than the impurity concentration of the N+ type impurity diffusion layer. Therefore, the capacitance of the PN junction becomes smaller as compared to the conventional case where the N type impurity diffusion layer is provided directly at the surface of a P type semiconductor substrate. Therefore, reflection and attenuation of an input signal are suppressed.
    Type: Application
    Filed: January 19, 2007
    Publication date: November 8, 2007
    Applicant: RENESAS TECHNOLOGY CORP.
    Inventors: Yasushi Hayakawa, Katsushi Asahina
  • Patent number: 7180137
    Abstract: A terminating resistance element of an LSI chip has an N? type impurity diffusion region formed at the surface of a P type well at the surface of a semiconductor substrate, an N+ type impurity diffusion layer formed at the surface of the N? type impurity diffusion region, and a pair of electrodes formed at respective ends at the surface of the N+ type impurity diffusion layer. The N? type impurity diffusion region has an impurity concentration lower than the impurity concentration of the N+ type impurity diffusion layer. Therefore, the capacitance of the PN junction becomes smaller as compared to the conventional case where the N type impurity diffusion layer is provided directly at the surface of a P type semiconductor substrate. Therefore, reflection and attenuation of an input signal are suppressed.
    Type: Grant
    Filed: April 29, 2004
    Date of Patent: February 20, 2007
    Assignee: Renesas Technology Corp.
    Inventors: Yasushi Hayakawa, Katsushi Asahina
  • Publication number: 20070018704
    Abstract: PD detects a phase difference between DATA and VDL output from VDL. Code Operator detects a value of a control code corresponding to a delay equal to one period of an output clock. Then, when a delay amount of VDL exceeds one period of a clock during synchronization of the output clock with the data signal while the control code is changed in accordance with the detection result by PD, a control code corresponding to a delay equal to one period of the output clock is added or subtracted to/from the control code at a time. Therefore, even if there is a difference in frequency between a data signal and a clock, it becomes possible to synchronize the data signal and the clock with application of the same clock phase.
    Type: Application
    Filed: June 30, 2006
    Publication date: January 25, 2007
    Applicant: Renesas Technology Corp.
    Inventors: Masashi Ishii, Takanori Hirota, Atsuhiko Ishibashi, Yasushi Hayakawa, Takeshi Oshita, Yoshiyuki Ota
  • Patent number: 7057445
    Abstract: A bias voltage generating circuit and a differential amplifier which can ensure a constant current through a constant current circuit in a differential amplifier circuit even in case that a common mode voltage of the reference voltage signal to the differential amplifier circuit changes are attained. A constant current is generated employing a current source (Isw) and a current mirror circuit composed of a transistor (M1 and M2). The constant current is supplied to a source of a transistor (M3). A drain and a gate of a transistor (M4) are connected with a drain of the transistor (M3). A reference voltage signal (Vref) to a differential amplifier circuit is inputted to a gate of the transistor (M3), and a drain potential of the transistor (M4) is made to function as a bias voltage (biasn) to a constant current circuit in the differential amplifier circuit.
    Type: Grant
    Filed: October 23, 2003
    Date of Patent: June 6, 2006
    Assignee: Renesas Technology Corp.
    Inventor: Yasushi Hayakawa
  • Publication number: 20050017795
    Abstract: A bias voltage generating circuit and a differential amplifier which can ensure a constant current through a constant current circuit in a differential amplifier circuit even in case that a common mode voltage of the reference voltage signal to the differential amplifier circuit changes are attained. A constant current is generated employing a current source (Isw) and a current mirror circuit composed of a transistor (M1 and M2). The constant current is supplied to a source of a transistor (M3). A drain and a gate of a transistor (M4) are connected with a drain of the transistor (M3). A reference voltage signal (Vref) to a differential amplifier circuit is inputted to a gate of the transistor (M3), and a drain potential of the transistor (M4) is made to function as a bias voltage (biasn) to a constant current circuit in the differential amplifier circuit.
    Type: Application
    Filed: October 23, 2003
    Publication date: January 27, 2005
    Applicant: Renesas Technology Corp.
    Inventor: Yasushi Hayakawa
  • Publication number: 20050001237
    Abstract: A terminating resistance element of an LSI chip has an N? type impurity diffusion region formed at the surface of a P type well at the surface of a semiconductor substrate, an N+ type impurity diffusion layer formed at the surface of the N? type impurity diffusion region, and a pair of electrodes formed at respective ends at the surface of the N+ type impurity diffusion layer. The N? type impurity diffusion region has an impurity concentration lower than the impurity concentration of the N+ type impurity diffusion layer. Therefore, the capacitance of the PN junction becomes smaller as compared to the conventional case where the N type impurity diffusion layer is provided directly at the surface of a P type semiconductor substrate. Therefore, reflection and attenuation of an input signal are suppressed.
    Type: Application
    Filed: April 29, 2004
    Publication date: January 6, 2005
    Inventors: Yasushi Hayakawa, Katsushi Asahina
  • Patent number: 6216827
    Abstract: A disc rotor used in a disc brake which generates a vibration having a large component in the axial direction of the disc rotor when a brake pad is pressed against the disc rotor. The disc rotor has a hat portion to be fixed to an axle hub of a vehicle. A sliding portion, which is pressed by a brake pad so as to generate a brake force, is connected to the hat portion via a connecting portion. A plurality of ribs are provided to increase a rigidity of the connecting portion. A low-rigidity portion having a rigidity less than the sliding portion and the connecting portion may be provided between the sliding portion and the connecting portion.
    Type: Grant
    Filed: July 16, 1997
    Date of Patent: April 17, 2001
    Assignees: Toyota Jidosha Kabushiki Kaisha, Aisin Takaoka Co., Ltd.
    Inventors: Yasuaki Ichiba, Naoki Tanabe, Yasushi Hayakawa
  • Patent number: 5969556
    Abstract: It is an object to enlarge the logical amplitude of an output signal of a flip-flop circuit with a suppressed, low power-supply voltage to reduce the possibility of occurrence of malfunction. A signal outputted from a differential amplification portion is converted in an internal level converting circuit and fed back to bases of transistors of a slave latch. With input signals having a high level at 0.5 V, the internal level converting circuit performs conversion to provide output signals having a high level at 0.25 V to prevent a current flowing between a collector and a base of the transistors.
    Type: Grant
    Filed: July 15, 1997
    Date of Patent: October 19, 1999
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Yasushi Hayakawa
  • Patent number: 5945843
    Abstract: A level conversion circuit as a semiconductor integrated circuit has a first load resistance (R1), a second load resistance (R2), a first NMOS transistor (MN3) and a second NMOS transistor (MN4) connected to them (R1 and R2) in parallel, respectively, that are driven directly by positive CMOS level signals, a first bipolar transistor (Q1), and a second bipolar transistor (Q2). Both emitters of the first and second bipolar transistors (Q1 and Q2) are connected commonly, and a voltage potential that is lower than a voltage potential of a collector of the first bipolar transistor (Q1) by a predetermined voltage potential is supplied into a base of the second bipolar transistor (Q2).
    Type: Grant
    Filed: October 24, 1997
    Date of Patent: August 31, 1999
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Takanori Hirota, Yasushi Hayakawa
  • Patent number: 5699002
    Abstract: The power consumption of a flip-flop circuit is reduced and an output magnitude is increased to prevent a malfunction from occurring often. In order to reduce the power consumption, an emitter-coupled logic with series gating is used for the master latch of the flip-flop circuit. A series gating is not used but an ECL having transistors connected in parallel is used for the gates of a slave latch so as to increase the output magnitude.
    Type: Grant
    Filed: January 17, 1996
    Date of Patent: December 16, 1997
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Yasushi Hayakawa
  • Patent number: 5574391
    Abstract: In an ECL circuit, when a potential of an input signal A changes from "L" to "H", an output signal D correspondingly changes from "H" to "L", and, at this time, an output sent from a switching stage circuit is supplied to a gate of a PMOS transistor via a control capacitor. Thereby, a base current of a pull-down transistor flows, and change of a potential of an output terminal node is promoted. An NMOS transistor receiving the potential of the output terminal node is arranged between a node and a VEE supply terminal. Therefore, when the potential changes, the current flowing through a transistor decreases, and the base current of the pull-down transistor further increases, so that the change of the output signal D is further promoted.
    Type: Grant
    Filed: May 30, 1995
    Date of Patent: November 12, 1996
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Toshiaki Hanibuchi, Yasushi Hayakawa, Masahiro Ueda
  • Patent number: 5530340
    Abstract: A clamping circuit (Q.sub.3) provides the second potential (V.sub.EE) with a clamp voltage which remains a constant value even if the second potential (V.sub.EE) varies, to obtain a clamp potential (V.sub.c). A little variation of the clamp voltage due to the variation of the second potential (V.sub.EE) is transferred to a current generating circuit (Q.sub.4) and then a feedback current (I.sub.3) is applied to a feedback circuit (Q.sub.2) in response to the variation of the clamp voltage. Since an output potential (V.sub.O) outputted from an output circuit (Q.sub.1) varies in response to the variation of the second potential (V.sub.EE), an output voltage which is a potential difference between the output potential (V.sub.O) and the second potential (V.sub.EE) remains at a constant value.
    Type: Grant
    Filed: December 16, 1994
    Date of Patent: June 25, 1996
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Yasushi Hayakawa, Masahiro Ueda
  • Patent number: 5479115
    Abstract: There is disclosed a signal processing device which includes a pre-processing circuit (31) for performing a serial-to-parallel conversion on an intermediate signal (M.sub.2) at a PECL level, the serial-to-parallel conversion at the PECL level being permitted to deal with a high frequency, and a level converter circuit (12) for performing a conversion from the ECL to PECL levels both having the same logic level width, which conversion consumes less power than a conversion between the ECL and CMOS levels having different logic level widths. The level conversion of a parallel signal requires less power consumed than a level conversion of a serial signal. The signal processing device further includes a level converter circuit (13) for performing a conversion into the CMOS level after obtaining an intermediate signal (M.sub.3) which is a parallel signal. An intermediate signal (M.sub.4) is at the CMOS level and has a low frequency.
    Type: Grant
    Filed: February 14, 1995
    Date of Patent: December 26, 1995
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Masahiro Ueda, Yasushi Hayakawa