Patents by Inventor Norito TAKAHASHI

Norito TAKAHASHI 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: 20220022299
    Abstract: A lighting circuit turns on a plurality of semiconductor light sources. Multiple current sources are each coupled to a corresponding semiconductor light source. A switching converter supplies a driving voltage VOUT across each of multiple series connection circuits each formed of the semiconductor light source and the current source. A converter controller employing a ripple control method turns on a switching transistor of the switching converter in response to a voltage across any one of the multiple current sources decreasing to a bottom limit voltage.
    Type: Application
    Filed: September 29, 2021
    Publication date: January 20, 2022
    Applicant: KOITO MANUFACTURING CO., LTD.
    Inventors: Tomoyuki ICHIKAWA, Ryosuke MATSUHANA, Satoshi KIKUCHI, Naoki KAWABATA, Norito TAKAHASHI
  • Publication number: 20220022300
    Abstract: A lighting circuit turns on a plurality of semiconductor light sources. Multiple current sources are each coupled to a corresponding semiconductor light source. A switching converter supplies a driving voltage VOUT across each of multiple series connection circuits each formed of the semiconductor light source and the current source. A converter controller employing a ripple control method turns on a switching transistor of the switching converter in response to a voltage across any one of the multiple current sources decreasing to a bottom limit voltage.
    Type: Application
    Filed: September 29, 2021
    Publication date: January 20, 2022
    Applicant: KOITO MANUFACTURING CO., LTD.
    Inventors: Tomoyuki ICHIKAWA, Ryosuke MATSUHANA, Satoshi KIKUCHI, Naoki KAWABATA, Norito TAKAHASHI
  • Publication number: 20210368603
    Abstract: Multiple current sources are coupled in series to corresponding light-emitting elements. Switching converter supplies driving voltage to the multiple light-emitting elements and current sources. Pulse modulator generates pulse signal that transits to on level when the smallest from among voltages across both ends of the multiple current sources falls to bottom limit voltage, and subsequently transits to off level. Frequency stabilization circuit controls pulse modulator such that the frequency of pulse signal approaches its target. Dummy load circuit is configured to lower driving voltage in the enable state, to be set to the enable state when switching transistor continues to be off for a predetermined time, and to be set to the disable state in response to the next turn-on of the switching transistor.
    Type: Application
    Filed: August 10, 2021
    Publication date: November 25, 2021
    Applicant: KOITO MANUFACTURING CO., LTD.
    Inventors: Norito TAKAHASHI, Satoshi KIKUCHI
  • Publication number: 20200275542
    Abstract: A lighting circuit turns on a plurality of semiconductor light sources. Multiple current sources are each coupled to a corresponding semiconductor light source. A switching converter supplies a driving voltage VOUT across each of multiple series connection circuits each formed of the semiconductor light source and the current source. A converter controller employing a ripple control method turns on a switching transistor of the switching converter in response to a voltage across any one of the multiple current sources decreasing to a bottom limit voltage.
    Type: Application
    Filed: May 14, 2020
    Publication date: August 27, 2020
    Applicant: KOITO MANUFACTURING CO., LTD.
    Inventors: Tomoyuki ICHIKAWA, Ryosuke MATSUHANA, Satoshi KIKUCHI, Naoki KAWABATA, Norito TAKAHASHI