Patents by Inventor Shigesato Iwasa

Shigesato Iwasa 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: 5446284
    Abstract: A monolithic detector array apparatus for sensing infrared radiation. An array of semiconductor diode bolometers are fabricated on micromachined thermal isolation structures called microbridges. The detectors are configured in an array and addressed by row and column. Readout circuitry may be optionally incorporated onto a common substrate. The monolithic detector array may be highly integrated, resulting in a low cost and a high performance focal plane array.
    Type: Grant
    Filed: January 25, 1994
    Date of Patent: August 29, 1995
    Assignee: Loral Infrared & Imaging Systems, Inc.
    Inventors: Neal R. Butler, Shigesato Iwasa
  • Patent number: 4902894
    Abstract: What is disclosed is a preamplier used with each pyroelectric detector in an infrared imaging array system. To construct each preamplifier and an associated detector in a dense detector array, solid state manufacturing techniques are utilized. To bias the preamplifier either a high bias impedance is effectively provided by doping the material from which the detector is made; or a MOSFET bias switch is provided that is periodically operated to place charge on the gate of the preamplifier transistor to maintain it at its bias level. When the bias switch is not operated, the associated detector detects and a reading is taken from each detector in the array.
    Type: Grant
    Filed: September 26, 1986
    Date of Patent: February 20, 1990
    Assignee: Honeywell Inc.
    Inventors: Neal R. Butler, Jeff L. McClelland, Shigesato Iwasa
  • Patent number: 4897547
    Abstract: What is disclosed is a preamplifier used with each pyroelectric detector in an infrared imaging array system. The preamplifier transistor is a MOSFET transistor that can operate with zero volts between its source and gate terminals, and the preamplifier is biased either by a nonconducting diode that provides a high biasing impedance while the bias voltage is low enough to keep the diode below its conduction voltage; or an NPN transistor switch is periodically operated to place charge on the gate of the preamplifier transistor to maintain it at its bias level. When the bias transistor is not operated, the associated detector detects and a detector reading is taken from each detector in the array. NPN transistor switches can be manufactured consistently and their conduction level can be adjusted to balance the gain of all preamplifiers in the detector array.
    Type: Grant
    Filed: September 26, 1986
    Date of Patent: January 30, 1990
    Assignee: Honeywell Inc.
    Inventors: Shigesato Iwasa, Neal R. Butler, Jeff L. McClelland
  • Patent number: 4831257
    Abstract: What is disclosed is a preamplifier used with each pyroelectric detector in an infrared imaging array system. To bias the preamplifiers either a MOSFET transistor is utilized as a switch that is periodically operated to place charge on the gate of the MOSFET preamplifier transistor to maintain it at its bias level, or an NPN transistor is operated at a level to provide high impedance. When the bias switch is not operated, the associated detector detects and a reading is taken from each detector in the array. NPN transistor switches can be manufactured consistently and their conduction level can be adjusted to balance the gain of all preamplifiers in the detector array. The supply voltage to the preamplifiers in the array is monitored by a feedback circuit which compares a supply voltage to a reference voltage and adjusts the preamplifier bias voltage to compensate for changes in the supply voltage.
    Type: Grant
    Filed: September 26, 1986
    Date of Patent: May 16, 1989
    Assignee: Honeywell Inc.
    Inventors: Jeff L. McClelland, Shigesato Iwasa, Neal R. Butler