Patents by Inventor Hirofumi YUMOTO

Hirofumi YUMOTO 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).

  • Optical rotation plate and liquid crystal display device using the same
    Patent number: 8531627
    Abstract: A main object of the present invention is to provide a rotating plate hardly generating variation in the rotation angle of the liner polarization so as to easily realize a desired rotation angle, and a liquid crystal display device enabling observation of a bright image by use thereof even in a state with a polarizing glasses put on. To attain the object, the present invention provides an optical rotation plate comprising a transparent substrate, and an optical rotation layer formed on the transparent substrate and containing a rod-shaped compound for forming a cholesteric structure and having a function of rotating transmitted liner polarization, wherein the cholesteric structure has a 90 degrees or larger twist angle and a pitch in a range of 450 nm to 4,000 nm.
    Type: Grant
    Filed: December 23, 2009
    Date of Patent: September 10, 2013
    Assignee: Dai Nippon Printing Co., Ltd.
    Inventors: Satoru Hamada, Keiji Kashima, Takashi Kuroda, Hirofumi Yumoto
  • OPTICAL ROTATION PLATE AND LIQUID CRYSTAL DISPLAY DEVICE USING THE SAME
    Publication number: 20100165258
    Abstract: A main object of the present invention is to provide a rotating plate hardly generating variation in the rotation angle of the liner polarization so as to easily realize a desired rotation angle, and a liquid crystal display device enabling observation of a bright image by use thereof even in a state with a polarizing glasses put on. To attain the object, the present invention provides an optical rotation plate comprising a transparent substrate, and an optical rotation layer formed on the transparent substrate and containing a rod-shaped compound for forming a cholesteric structure and having a function of rotating transmitted liner polarization, wherein the cholesteric structure has a 90 degrees or larger twist angle and a pitch in a range of 450 nm to 4,000 nm.
    Type: Application
    Filed: December 23, 2009
    Publication date: July 1, 2010
    Applicant: DAI NIPPON PRINTING CO., LTD.
    Inventors: Satoru HAMADA, Keiji KASHIMA, Takashi KURODA, Hirofumi YUMOTO