Patents by Inventor Kenro Oguri

Kenro Oguri 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: 4099139
    Abstract: A power amplifier circuit comprising a voltage amplifier stage and a current amplifier stage, the mode of bias of which can be changed over between class A and class B (AB). The supply voltage for the current amplifier stage is changed over by a mode selection switch. The change in the supply voltage is detected to select the bias voltage for the current amplifier stage.The possibility of applying a class A bias to the current amplifier stage supplied with a class B line voltage is thus completely removed.
    Type: Grant
    Filed: February 8, 1977
    Date of Patent: July 4, 1978
    Assignee: Nippon Gakki Seizo Kabushiki Kaisha
    Inventor: Kenro Oguri
  • Patent number: 4054844
    Abstract: An amplifying system comprises an amplifier having a certain constant gain, a first variable attenuator through which an input signal for this system is inputted to the amplifier, and a second variable attenuator through which the output signal of the amplifier is delivered. The over-all gain of the system is variable from the minimum gain to the maximum gain by gang-operating the two variable attenuators. The two variable attenuators are of such a construction that the attenuation factor of the first attenuator is substantially variable in the operation range near the middle of the variable gain whereas that of the second attenuator is substantially variable in the operation ranges near the minimum and maximum of the variable gain. When the input signal level is low, the second attenuator functions in the near-maximum range, and when high, the first attenuator functions in the middle range, thus delivering an output signal at the rated level.
    Type: Grant
    Filed: April 13, 1976
    Date of Patent: October 18, 1977
    Assignee: Nippon Gakki Seizo Kabushiki Kaisha
    Inventor: Kenro Oguri