Patents by Inventor Ritsuo Oka

Ritsuo Oka 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).

  • Surge protection semiconductor device
    Patent number: 6870202
    Abstract: A pnpn thyristor element Thy1 and six pn diode elements D1, D2, D3, D4, D5, and D6 are formed in a semiconductor substrate of a first conductivity type, and separated into six regions by a diffusion layer of a second conductivity type which also functions as the anode of the thyristor element Thy1. A double isolation diffusion layer is disposed between the region of the thyristor element Thy1 and three pn diode elements D1 ·D2 and D6, and the region of the three remaining pn diodes D3, D4, and D5. Surface connection is performed to provide a balance type surge protection circuit.
    Type: Grant
    Filed: April 30, 2004
    Date of Patent: March 22, 2005
    Assignee: Shindengen Electric Manufacturing Co., Ltd.
    Inventor: Ritsuo Oka
  • Surge protection semiconductor device
    Publication number: 20040201035
    Abstract: A pnpn thyristor element Thy1 and six pn diode elements D1, D2, D3, D4, D5, and D6 are formed in a semiconductor substrate of a first conductivity type, and separated into six regions by a diffusion layer of a second conductivity type which also functions as the anode of the thyristor element Thy1. A double isolation diffusion layer is disposed between the region of the thyristor element Thy1 and three pn diode elements D1 . D2 and D6, and the region of the three remaining pn diodes D3, D4, and D5. Surface connection is performed to provide a balance type surge protection circuit.
    Type: Application
    Filed: April 30, 2004
    Publication date: October 14, 2004
    Inventor: Ritsuo Oka