Patents by Inventor Keiko Kurata

Keiko Kurata 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: 6532046
    Abstract: The object of the present invention is to provide a novel liquid crystal display material having an excellent contrast ratio, a display method and a display device using the material. The present invention uses a liquid crystal display material comprising a polymer in which a liquid crystal is dispersed in a dissolvable state or a phase separable state, wherein the liquid crystal dissolves in the polymer at high temperatures and separates from the polymer at low temperatures, and a contrast ratio (B/A) of a reflectance (A) of the display material cooled from the dissolution state at a rate of 10° C./sec and a reflectance (B) of the display material cooled from the dissolution state at a rate of 4° C./sec is not less than 2. The image forming state can be maintained by controlling the cooling rate from the dissolution state to maintain the liquid crystal in translucent state.
    Type: Grant
    Filed: October 25, 2000
    Date of Patent: March 11, 2003
    Assignee: Hitachi Maxell, Ltd.
    Inventors: Yuji Yamashita, Keiko Kurata, Kouji Ooae, Ryuzo Fukao
  • Patent number: 6037400
    Abstract: The present invention relates to a lightweight and flexible material for prevention of electric waves having both absorbing properties and shielding properties against electric waves. In the present invention, carbon fiber or magnetic particles, or both and graphitized carbon black are dispersed and incorporated into an insulating substrate so that the weight ratio of the graphitized carbon black to the carbon fiber, the magnetic particles or the sum of the two may be 0.3 to 5.
    Type: Grant
    Filed: August 25, 1998
    Date of Patent: March 14, 2000
    Assignees: Hitachi Maxell, Ltd, Yoshio Nikawa, Masaru Chino
    Inventors: Shinichi Kitahata, Keiko Kurata, Yoshio Nikawa, Masaru Chino
  • Patent number: 5952953
    Abstract: A wave absorber which is light in weight, rich in flexibility and excellent in wave absorption characteristics in a microwave frequency range. The wave absorber in which composite carbon black particles including crystalline graphite and amorphous carbon black are dispersed into an insulating matrix. In the wave absorber, dispersion of the composite carbon black particles is adjusted so that a ratio (.rho./R) of a volume resistivity .rho. measured at frequencies of 30, 100 and 500 kHz to a measured DC volume resistivity R is in a predetermined range and a volume ratio of the composite carbon black particles having particle diameters of 10 nm to 200 nm to all the composite carbon black particles is in a range of 5% to 95%. Thereby, a wave absorber excellent in absorption characteristics is obtained.
    Type: Grant
    Filed: March 13, 1998
    Date of Patent: September 14, 1999
    Assignees: Hitachi Maxell, Ltd., Yoshio Nikawa, Masaru Chino
    Inventors: Yoshio Nikawa, Masaru Chino, Shinichi Kitahata, Keiko Kurata