Patents by Inventor Hirosi Koinuma

Hirosi Koinuma 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).

  • Power amplifier
    Patent number: 4451802
    Abstract: A power amplifier includes a class A power amplifier and a class B power amplifier driven by the same input signal. The class A amplifier includes a pair of load driving power amplifying elements, and a further pair of amplifying elements serves to drive the power amplifying elements. To obtain good operating characteristics and reduce distortion, the further pair of elements are powered by power supplies for the class B amplifier.
    Type: Grant
    Filed: June 11, 1982
    Date of Patent: May 29, 1984
    Assignee: Pioneer Electronic Corporation
    Inventor: Hirosi Koinuma
  • Power amplifier
    Patent number: 4443771
    Abstract: In a power amplifier circuit the ends of the DC source for the class A stage are isolated from the amplifier transistors by diode. A resistor may also be connected across the class A amplifier diodes.
    Type: Grant
    Filed: December 9, 1981
    Date of Patent: April 17, 1984
    Assignee: Pioneer Electronic Corporation
    Inventors: Satoshi Ishii, Hirosi Koinuma