Patents by Inventor Seiko Nakamoto

Seiko Nakamoto 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: 11329743
    Abstract: In a transmission system of an audio signal etc., circuit enlargement is suppressed and deterioration of transmitting signal is reduced. A transmission system including a transmitting apparatus including a first delta-sigma modulator outputting first multi-bit delta-sigma modulated signals of three or more bits and a first code modulator code-modulating first signals of two or more bits located in bit positions higher than a predetermined bit position of the first multi-bit delta-sigma modulated signals based on at least part of a second signal located in one or more bit positions not higher than the predetermined bit position and outputting a plurality of modulated signals; a transmission path transmitting the second signal and the plurality of modulated signals; and a receiving apparatus including a first demodulator demodulating the plurality of the received modulated signals based on at least part of the received second signal is provided.
    Type: Grant
    Filed: April 6, 2020
    Date of Patent: May 10, 2022
    Assignee: Asahi Kasei Microdevices Corporation
    Inventor: Seiko Nakamoto
  • Publication number: 20200374020
    Abstract: In a transmission system of an audio signal etc., circuit enlargement is suppressed and deterioration of transmitting signal is reduced. A transmission system including a transmitting apparatus including a first delta-sigma modulator outputting first multi-bit delta-sigma modulated signals of three or more bits and a first code modulator code-modulating first signals of two or more bits located in bit positions higher than a predetermined bit position of the first multi-bit delta-sigma modulated signals based on at least part of a second signal located in one or more bit positions not higher than the predetermined bit position and outputting a plurality of modulated signals; a transmission path transmitting the second signal and the plurality of modulated signals; and a receiving apparatus including a first demodulator demodulating the plurality of the received modulated signals based on at least part of the received second signal is provided.
    Type: Application
    Filed: April 6, 2020
    Publication date: November 26, 2020
    Inventor: Seiko NAKAMOTO
  • Patent number: 9246502
    Abstract: The present invention relates to a control method of a D/A converter, a D/A converter, a control method of an A/D converter, and an A/D converter that can suppress an existing n-th harmonic without using a large-scale circuit, such as a bootstrap. A D/A converter (10) of the present invention is a D/A converter (10) that can suppress the generation of an existing n-th harmonic (n is an integer of 2 or more) of an analog output signal. The D/A converter (10) includes a D/A conversion unit (11) that converts an input digital signal into an analog signal and a control unit (12) that arbitrarily controls the timing of the sampling phase and the integral phase of the D/A conversion unit (11). The D/A conversion unit (11) is configured to generate an arbitrary n-th harmonic and superimpose the arbitrary n-th harmonic on an analog output signal including the existing n-th harmonic.
    Type: Grant
    Filed: August 13, 2014
    Date of Patent: January 26, 2016
    Assignee: Asahi Kasei Microdevices Corporation
    Inventors: Ryuzo Yamamoto, Junya Nakanishi, Seiko Nakamoto
  • Publication number: 20150256191
    Abstract: The present invention relates to a control method of a D/A converter, a D/A converter, a control method of an A/D converter, and an A/D converter that can suppress an existing n-th harmonic without using a large-scale circuit, such as a bootstrap. A D/A converter (10) of the present invention is a D/A converter (10) that can suppress the generation of an existing n-th harmonic (n is an integer of 2 or more) of an analog output signal. The D/A converter (10) includes a D/A conversion unit (11) that converts an input digital signal into an analog signal and a control unit (12) that arbitrarily controls the timing of the sampling phase and the integral phase of the D/A conversion unit (11). The D/A conversion unit (11) is configured to generate an arbitrary n-th harmonic and superimpose the arbitrary n-th harmonic on an analog output signal including the existing n-th harmonic.
    Type: Application
    Filed: August 13, 2014
    Publication date: September 10, 2015
    Applicant: ASAHI KASEI MICRODEVICES CORPORATION
    Inventors: Ryuzo Yamamoto, Junya Nakanishi, Seiko Nakamoto
  • Patent number: 8917196
    Abstract: An A/D converter comprising: a sampling circuit including a continuous section, a sampling and holding section for intermittently sampling an input signal based on an analog signal input from the continuous section to hold and transfer the sampled signal, and a digital section for outputting a signal transferred from the sampling and holding section as a digital signal; and a control circuit for supplying a clock signal in which jitter is not added to the continuous section and supplying a clock signal in which the jitter is added to the sampling and holding section.
    Type: Grant
    Filed: December 27, 2012
    Date of Patent: December 23, 2014
    Assignee: Asahi Kasei Microdevices Corporation
    Inventors: Junya Nakanishi, Yutaka Nakanishi, Seiko Nakamoto
  • Patent number: 8830100
    Abstract: A digital-analog converter circuit includes sampling capacitive elements (111, 112, . . . , 11N) of which one ends are to be electrically connected to and disconnected from input terminals (D1, D2, . . . , DN), to which digital signals are input, via a switch unit (SWu10), an operational amplifier (501), a switch (301) capable of electrically connecting and disconnecting the other ends of the sampling capacitive elements (111, 112, . . . , 11N) and an inverting input terminal of the operational amplifier (501), and a switch unit (SWu40) that is disposed between nodes between the switch unit (SWu10) and the sampling capacitive elements (111, 112, . . . , 11N) and the output terminal of the operational amplifier (501) and capable of connecting and disconnecting them. An on-resistance value of a MOS transistor included in the switch (301) is set to be larger than an on-resistance value of a MOS transistor included in the switch unit (SWu40).
    Type: Grant
    Filed: October 31, 2012
    Date of Patent: September 9, 2014
    Assignee: Asahi Kasei Microdevices Corporation
    Inventors: Seiko Nakamoto, Junya Nakanishi
  • Publication number: 20140097977
    Abstract: A digital-analog converter circuit includes sampling capacitive elements (111, 112, . . . , 11N) of which one ends are to be electrically connected to and disconnected from input terminals (D1, D2, . . . , DN), to which digital signals are input, via a switch unit (SWu10), an operational amplifier (501), a switch (301) capable of electrically connecting and disconnecting the other ends of the sampling capacitive elements (111, 112, . . . , 11N) and an inverting input terminal of the operational amplifier (501), and a switch unit (SWu40) that is disposed between nodes between the switch unit (SWu10) and the sampling capacitive elements (111, 112, . . . , 11N) and the output terminal of the operational amplifier (501) and capable of connecting and disconnecting them. An on-resistance value of a MOS transistor included in the switch (301) is set to be larger than an on-resistance value of a MOS transistor included in the switch unit (SWu40).
    Type: Application
    Filed: October 31, 2012
    Publication date: April 10, 2014
    Applicant: ASAHI KASEI MICRODEVICES CORPORATION
    Inventors: Seiko Nakamoto, Junya Nakanishi
  • Publication number: 20140062742
    Abstract: An A/D converter comprising: a sampling circuit including a continuous section, a sampling and holding section for intermittently sampling an input signal based on an analog signal input from the continuous section to hold and transfer the sampled signal, and a digital section for outputting a signal transferred from the sampling and holding section as a digital signal; and a control circuit for supplying a clock signal in which jitter is not added to the continuous section and supplying a clock signal in which the jitter is added to the sampling and holding section.
    Type: Application
    Filed: December 27, 2012
    Publication date: March 6, 2014
    Applicant: ASAHI KASEI MICRODEVICES CORPORATION
    Inventors: Junya Nakanishi, Yutaka Nakanishi, Seiko Nakamoto