Patents by Inventor Dale Sumida

Dale Sumida 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: 5357393
    Abstract: An integrated high voltage device with an ultra low leakage input protection circuit to be used in highly sensitive circuits which require ultra low input leakage current. The protection circuit has a common substrate with the integrated circuit device and the common substrate is floating. The floating substrate provides a way of designing a protection circuit with small diodes which have ultra low input D.C. leakage. The protection circuit includes a resistor and two small Zener diodes which can clamp and protect the device during normal operating conditions up to voltages such as 1700 volts.
    Type: Grant
    Filed: May 5, 1992
    Date of Patent: October 18, 1994
    Assignee: Xerox Corporation
    Inventors: Mohamad M. Mojaradi, Guillermo Lao, Dale Sumida
  • Patent number: 5329155
    Abstract: A thin film integrated circuit resistor is disclosed that is substantially linear at applied voltages greater than 100 volts. The integrated circuit resistor comprises a substrate, a plurality of resistive blocks electrically connected in series, a shield associated with each resistive block, and passivation means for isolating the substrate from the resistive blocks and the shields, and for isolating the shields from the resistive blocks except where they are electrically connected. Each shield substantially surrounds its associated resistive block with conductive material, and each shield is electrically connected to its resistive block such that each shield is at a potential of some point along the length of its associated resistive block.
    Type: Grant
    Filed: April 24, 1990
    Date of Patent: July 12, 1994
    Assignee: Xerox Corporation
    Inventors: Guillermo Lao, Dale Sumida, Anh K. Hoang-Le, Mohamad Mojaradi, Tuan A. Vo
  • Patent number: 5304836
    Abstract: The present invention is directed to a high voltage field effect transistor (FET) constructed on the major surface of a substrate of a first conductivity type. The FET includes a drain region of a second conductivity type located in the major surface and a generally annular drift region of the second conductivity type, located in the major surface and outside of the drain region. A generally annular gate is located on the major surface and outside of the drift region, and a generally annular source region is located in the major surface and outside of the gate. A first channel stop is located in the major surface and outboard of the source region, and a second channel stop located in the major surface and beneath the gate, having at least two portions in close proximity to each other. A channel region is located in the major surface and between the two second channel stop portions. The second channel stop blocks communication between the source region and the drift region except through the channel region.
    Type: Grant
    Filed: May 4, 1992
    Date of Patent: April 19, 1994
    Assignee: Xerox Corporation
    Inventors: Guillermo Lao, Dale Sumida, Anh K. Hoang-Le
  • Patent number: 5270660
    Abstract: An electrostatic measurement apparatus for generating a modified electrical signal in proportion to an electrostatic potential present on a surface. The apparatus includes a sensor for producing a signal representative of the electrostatic potential on the surface. The apparatus also includes high-voltage and low-voltage devices combined to produce an amplifier which transforms the sensor signal into a low-voltage signal indicative the surface potential. The electrostatic measurement apparatus is implemented using high-voltage and low-voltage integrated circuit technology.
    Type: Grant
    Filed: May 5, 1992
    Date of Patent: December 14, 1993
    Assignee: Xerox Corporation
    Inventors: Alan J. Werner, Jr., Mohamad M. Mojaradi, Guillermo Lao, Dale Sumida, Mostafa R. Yazdy, Harry J. McIntyre, Mehrdad Zomorrodi