Patents by Inventor Shigemitsu Hirayama

Shigemitsu Hirayama 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: 5064529
    Abstract: A membrane filter testing apparatus uses a control circuit for increasing the pressure at the primary side of a membrane filter fixedly accommodated in a housing and wetted with a liquid, by a gas at a predetermined rate, and checking whether the pressure at the primary side of the membrane filter is within a specified judging range after lapse of a predetermined period of time.
    Type: Grant
    Filed: August 22, 1989
    Date of Patent: November 12, 1991
    Assignee: Fujisawa Pharmaceutical Co., Ltd.
    Inventors: Shigemitsu Hirayama, Takamichi Akashi, Akio Ikuta, Isao Sasaki, Hiroshi Fukuda
  • Patent number: 4872974
    Abstract: A membrane filter testing method comprises increasing the pressure at the primary side of a membrane filter fixedly accommodated in a housing and wetted with a liquid, by a gas at a predetermined rate, and checking whether the pressure at the primary side of the membrane filter is within a specified judging range after lapse of a predetermined period of time.
    Type: Grant
    Filed: December 27, 1988
    Date of Patent: October 10, 1989
    Assignee: Fujisawa Pharmaceutical Co., Ltd.
    Inventors: Shigemitsu Hirayama, Takamichi Akashi, Akio Ikuta, Isao Sasaki, Hiroshi Fukuda