Patents by Inventor Yukiyo Niwa

Yukiyo Niwa 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).

  • Publication number: 20070117208
    Abstract: A radiation exposure history indicator sheet comprises a base material sheet which has a color-changing layer on at least a part of the surface comprising: a polymer compound having a hydroxyl group and at least one group selected from a halogen group and an acetal group; a coloring organic electron donor compound; an active species-generating organic compound for making the organic electron donor compound colored by a radiation; and a radiation absorbent and/or a radiation-excite fluorescent agent.
    Type: Application
    Filed: November 5, 2004
    Publication date: May 24, 2007
    Applicant: Nichiyu Giken Kogyo Co., Ltd.
    Inventor: Yukiyo Niwa
  • Patent number: 6406914
    Abstract: The present composition for use in radiation exposure dose-history indicators comprises a radioactive ray-absorber and/or a radioactive ray-excited fluorescence-emitting agent, a color-developing and electron-donating organic compound and an active species-generating organic compound, which can initiate the color development of the electron-donating organic compound through the application of radioactive rays. The indicator sheet for indicating the radiation exposure dose-history comprises a matrix sheet; and a color-developing layer, which contains a color-developing and electron-donating organic compound, an active species-generating organic compound, which can initiate the color development of the electron-donating organic compound through the application of radioactive rays, and a radioactive ray-absorber and/or a radioactive ray-excited fluorescence-emitting agent and which is applied to at least part of the surface of the matrix sheet.
    Type: Grant
    Filed: February 25, 2000
    Date of Patent: June 18, 2002
    Assignee: Nichiyu Giken Kogyo Co., Ltd.
    Inventors: Yoshiaki Kaburaki, Daisuke Harumoto, Hiromichi Mizusawa, Yukiyo Niwa, Hitoshi Shirase