Patents by Inventor Mamoru Sekiya

Mamoru Sekiya 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: 20090214075
    Abstract: The loudspeaker includes a dome diaphragm that is made of a base material impregnated in a thermosetting resin; a cone diaphragm whose outer circumference side end portion is coupled with an outer circumference end portion of the dome diaphragm; and a voice coil having a bobbin whose one end is coupled to a back surface of the dome diaphragm, and whose outer curved surface is coupled with an inner circumference end portion of the cone diaphragm, wherein the dome diaphragm is provided with a plurality of cone-shaped projections that is formed by hardening the thermosetting resin, projecting from the back surface, and disposed in a circular pattern with a space between each other, the plurality of cone-shaped projections defining a coupling portion to which the one end of the bobbin is coupled.
    Type: Application
    Filed: January 28, 2009
    Publication date: August 27, 2009
    Inventors: Takeru INOUE, Mamoru Sekiya
  • Publication number: 20090140786
    Abstract: A pulse width modulation circuit includes a first electric-charge accumulator; a second electric-charge accumulator; a first current generator which generates a first current corresponding to the amplitude of an input AC voltage; a second current generator which generates a second current with a constant value; a first current supply controller which supplies the first current to the first electric-charge accumulator; a second current supply controller which supplies the second current to the first electric-charge accumulator; a third current supply controller which supplies the first current to the second electric-charge accumulator; a fourth current supply controller which supplies the second current to the second electric-charge accumulator; and a current limiter which limits the first current to a third current with a predetermined current value, if the amplitude of the AC voltage in the negative side exceeds a predetermined level.
    Type: Application
    Filed: December 1, 2008
    Publication date: June 4, 2009
    Inventors: Yoshinori NAKANISHI, Mamoru SEKIYA
  • Publication number: 20090121342
    Abstract: A semiconductor device according to a preferred embodiment of the present invention is a semiconductor device including a main substrate and one or more sub substrates, and the semiconductor device includes first heat generating devices mounted on the sub substrates, sub-substrate heatsinks mounted to the first heat generating devices, and a main-substrate heatsink mounted to the main substrate, wherein the sub-substrate heatsinks and the main-substrate heatsink are secured to each other, such that there is a predetermined positional relationship between the sub substrates and the main substrate.
    Type: Application
    Filed: June 10, 2008
    Publication date: May 14, 2009
    Inventors: Atsushi MINAKAWA, Mamoru SEKIYA, Norio UMEZU
  • Publication number: 20090066377
    Abstract: A pulse width modulation circuit of the present invention changes a voltage of a charging circuit based on an input signal voltage and in synchronization with a first switching signal; changes, during a predetermined second period following a first period during which the voltage of the charging unit is changed, the voltage of the charging unit in an opposite direction to a direction in which the voltage is changed during the first period, based on a constant bias current; detects time starting from when the second period starts to when the voltage of the charging unit reaches a predetermined reference voltage; and generates, based on the detected time which is repeatedly output each time the first switching signal is output, a pulse signal having a pulse width of the time.
    Type: Application
    Filed: August 22, 2008
    Publication date: March 12, 2009
    Inventors: Yoshinori NAKANISHI, Mamoru SEKIYA
  • Patent number: 7466192
    Abstract: A low-pass filter with a high signal-to-noise ratio is provided. A low-pass filter includes a first RC filter circuit, a differential operation circuit subtracting an output signal from a low frequency component of an input signal and outputting a differential signal, a second RC filter circuit, a voltage-current conversion circuit, and a capacitor. The voltage-current conversion circuit includes an operational amplifier, a first resistor, and a feedback circuit generating a feedback voltage in accordance with a voltage applied to the first resistor. If resistance values of first to fourth resistors are R1, R2, R3, R4, a relational expression of R1*R3=R2*R4 is satisfied, and output current i becomes constant regardless of a resistance value of a load resistance. Since only a first resistor is connected between the input and the output of the voltage-current conversion circuit, thermal noise decreases, and a signal-to-noise ratio becomes high.
    Type: Grant
    Filed: April 25, 2007
    Date of Patent: December 16, 2008
    Assignee: Onkyo Corporation
    Inventors: Masatoshi Nakabo, Mamoru Sekiya, Masaaki Inoue
  • Patent number: 7456668
    Abstract: A pulse width modulation circuit 1 of the present invention changes the voltage of a first integration circuit C1 during the first period T1 of the clock signal MCLK based on a current based on an audio signal eS, changes the voltage of the first integration circuit C1 based on a constant bias current in the opposite direction while changing the voltage of a second integration circuit C2 during the second period T2, and changes the voltage of the second integration circuit C2 based on the bias current during the third period T3. The amount of time from the start of the second period T2 until the voltage of the first integration circuit C1 reaches the reference voltage Vth is detected, and the amount of time from the start of the third period T3 until the voltage of the second integration circuit C2 reaches the reference voltage Vth is detected.
    Type: Grant
    Filed: October 19, 2007
    Date of Patent: November 25, 2008
    Assignee: Onkyo Corporation
    Inventors: Yoshinori Nakanishi, Mamoru Sekiya
  • Publication number: 20080174351
    Abstract: A pulse width modulation circuit 1 of the present invention changes the voltage of a first integration circuit C1 during the first period T1 of the clock signal MCLK based on a current based on an audio signal eS, changes the voltage of the first integration circuit C1 based on a constant bias current in the opposite direction while changing the voltage of a second integration circuit C2 during the second period T2, and changes the voltage of the second integration circuit C2 based on the bias current during the third period T3. The amount of time from the start of the second period T2 until the voltage of the first integration circuit C1 reaches the reference voltage Vth is detected, and the amount of time from the start of the third period T3 until the voltage of the second integration circuit C2 reaches the reference voltage Vth is detected.
    Type: Application
    Filed: October 19, 2007
    Publication date: July 24, 2008
    Inventors: Yoshinori NAKANISHI, Mamoru Sekiya
  • Publication number: 20080149805
    Abstract: The present invention provides a vibration-damping structure for an audio apparatus, accommodating a main transformer, which becomes a vibration source when driven, the vibration-damping structure including: a main chassis to which a signal processing board for processing an audio signal is attached, the first chassis defining a portion of an outer shape of an assembly of the vibration-damping structure; a sub-chassis fastened to an inner surface of the main chassis so as to be partially in contact with the inner surface of the main chassis via a plurality of fastening members; and a component accommodating chassis fastened to an inner surface of the sub-chassis so as to be partially in contact with the inner surface of the sub-chassis via other fastening members, wherein the main transformer is fixed to the component accommodating chassis.
    Type: Application
    Filed: July 11, 2007
    Publication date: June 26, 2008
    Inventors: Tsuyoshi Morohashi, Mamoru Sekiya, Norio Etoh, Norimasa Kitagawa
  • Publication number: 20080062023
    Abstract: A low-pass filter with a high signal-to-noise ratio is provided. A low-pass filter includes a first RC filter circuit, a differential operation circuit subtracting an output signal from a low frequency component of an input signal and outputting a differential signal, a second RC filter circuit, a voltage-current conversion circuit, and a capacitor. The voltage-current conversion circuit includes an operational amplifier, a first resistor, and a feedback circuit generating a feedback voltage in accordance with a voltage applied to the first resistor. If resistance values of first to fourth resistors are R1, R2, R3, R4, a relational expression of R1*R3=R2*R4 is satisfied, and output current i becomes constant regardless of a resistance value of a load resistance. Since only a first resistor is connected between the input and the output of the voltage-current conversion circuit, thermal noise decreases, and a signal-to-noise ratio becomes high.
    Type: Application
    Filed: April 25, 2007
    Publication date: March 13, 2008
    Inventors: Masatoshi Nakabo, Mamoru Sekiya, Masaaki Inoue
  • Patent number: 7224217
    Abstract: A switching amplifier including a PWM circuit 14, a driver 15, a switching output circuit 16 and an LPF 17 is provided with a fluctuation detection circuit 12 for detecting fluctuations in the power supply voltage. The fluctuation detection circuit 12 includes detection resistors 122 and 123 connected in series between a positive power supply 19 and a negative power supply 20. A fluctuating signal RPL occurring at a fluctuation detection terminal 121 is supplied to the inverted input terminal of a differential amplifier 131 of a non-inverted amplifier circuit 13. The non-inverted amplifier circuit 13 inverts the fluctuating signal RPL, mixes the inverted fluctuating signal into the input signal eS, amplifies the mixed signal, and supplying the amplified signal to the PWM circuit 14.
    Type: Grant
    Filed: February 28, 2005
    Date of Patent: May 29, 2007
    Assignee: Onkyo Corporation
    Inventors: Kazuhiro Hida, Joji Kasai, Yoshitaka Handa, Sou Fujioka, Mamoru Sekiya
  • Publication number: 20050212592
    Abstract: A switching amplifier including a PWM circuit 14, a driver 15, a switching output circuit 16 and an LPF 17 is provided with a fluctuation detection circuit 12 for detecting fluctuations in the power supply voltage. The fluctuation detection circuit 12 includes detection resistors 122 and 123 connected in series between a positive power supply 19 and a negative power supply 20. A fluctuating signal RPL occurring at a fluctuation detection terminal 121 is supplied to the inverted input terminal of a differential amplifier 131 of a non-inverted amplifier circuit 13. The non-inverted amplifier circuit 13 inverts the fluctuating signal RPL, mixes the inverted fluctuating signal into the input signal eS, amplifies the mixed signal, and supplying the amplified signal to the PWM circuit 14.
    Type: Application
    Filed: February 28, 2005
    Publication date: September 29, 2005
    Inventors: Kazuhiro Hida, Joji Kasai, Yoshitaka Handa, Sou Fujioka, Mamoru Sekiya
  • Patent number: 6697002
    Abstract: A low-pass filter (700) includes a differential operation circuit (2), a voltage-current conversion circuit (3), and a capacitor (C1). The voltage-current conversion circuit (3) and the capacitor (C1) form a filter circuit (700), and therefore the low-pass filter can remove a high frequency component. The differential operation circuit (2) outputs a differential signal (&phgr;C) for the difference between an analog signal (&phgr;A) and an output signal (&phgr;B). Therefore, with the differential operation circuit (2), a necessary frequency band is not attenuated. The phase level of the output signal (&phgr;B) output from the low-pass filter (700) can be substantially equal to that of the analog signal (&phgr;A) by the differential operation circuit (2). Therefore, the low-pass filter have a higher attenuation ratio for a high frequency component.
    Type: Grant
    Filed: January 15, 2003
    Date of Patent: February 24, 2004
    Assignee: Onkyo Corporation
    Inventors: Mamoru Sekiya, Youichi Kudoh, Satomi Yamaguchi
  • Publication number: 20030132869
    Abstract: A low-pass filter (700) includes a differential operation circuit (2), a voltage-current conversion circuit (3), and a capacitor (C1). The voltage-current conversion circuit (3) and the capacitor (C1) form a filter circuit (700), and therefore the low-pass filter can remove a high frequency component. The differential operation circuit (2) outputs a differential signal (&phgr;C) for the difference between an analog signal (&phgr;A) and an output signal (&phgr;B). Therefore, with the differential operation circuit (2), a necessary frequency band is not attenuated. The phase level of the output signal (&phgr;B) output from the low-pass filter (700) can be substantially equal to that of the analog signal (&phgr;A) by the differential operation circuit (2). Therefore, the low-pass filter have a higher attenuation ratio for a high frequency component.
    Type: Application
    Filed: January 15, 2003
    Publication date: July 17, 2003
    Applicant: ONKYO CORPORATION
    Inventors: Mamoru Sekiya, Youichi Kudoh, Satomi Yamaguchi
  • Patent number: 5030858
    Abstract: A noise prevention circuit of a digital audio circuit having an input side and an output side includes a signal level retention circuit having first and second inputs and first and second outputs, for retaining a level of a transmitted signal; and a switch circuit operably coupled to the signal level retention circuit for respectively connecting the first and second inputs of the retention circuit to an active line and a ground line of the input side of the digital audio circuit. The retention circuit receives and retains input signal from the active line and the ground line of the input side of the digital audio circuit, and for alternatively connecting an active line and a ground line of the output side of the digital audio circuit. The retention circuit outputs the retained signal in the signal level retention circuit from the first and second outputs of the signal level retention circuit to the active line and the ground line of the output side of the digital audio circuit.
    Type: Grant
    Filed: July 19, 1990
    Date of Patent: July 9, 1991
    Assignee: Shin-Shirasuna Electric Corp.
    Inventor: Mamoru Sekiya
  • Patent number: 4072907
    Abstract: An amplifier circuit comprising a differential circuit including means for preventing base bias voltages applied to driver transistors connected with the transistors constituting the differential amplifier from becoming unbalanced. Means is also provided which is adapted to prevent so-called shock noise from appearing at the output of the amplifier circuit. Such means may be constructed by using a delay circuit.
    Type: Grant
    Filed: November 11, 1976
    Date of Patent: February 7, 1978
    Assignee: Shin-Shirasuna Electric Corp.
    Inventors: Mamoru Sekiya, Nobuyuki Sakabe