Patents by Inventor Ikumi Ichihashi

Ikumi Ichihashi 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: 8847367
    Abstract: Provided are a hole-injecting material for an organic electroluminescent device (organic EL device) exhibiting high luminous efficiency at a low voltage and having greatly improved driving stability, and an organic EL device using the material. The hole-injecting material for an organic EL device is selected from benzenehexacarboxylic acid anhydrides, benzenehexacarboxylic acid imides, or N-substituted benzenehexacarboxylic acid imides. Further, the organic EL device has at least one light-emitting layer and at least one hole-injecting layer between an anode and a cathode arranged opposite to each other, and includes the above-mentioned hole-injecting material for an organic EL device in the hole-injecting layer. The organic EL device may contain a hole-transporting material having an ionization potential (IP) of 6.0 eV or less in the hole-injecting layer or a layer adjacent to the hole-injecting layer.
    Type: Grant
    Filed: February 27, 2009
    Date of Patent: September 30, 2014
    Assignee: Nippon Steel & Sumikin Chemical Co., Ltd.
    Inventors: Takayuki Fukumatsu, Ikumi Ichihashi, Hiroshi Miyazaki, Atsushi Oda
  • Patent number: 8758904
    Abstract: Disclosed is an organic electroluminescent device (organic EL device) which can achieve high efficiency and long lifetime even when driven at low voltage. The organic El device comprises at least a light-emitting layer and an electron-transporting layer between an anode and a cathode facing each other. The electron-transporting layer consists of two layers, namely, a first electron-transporting layer and a second electron-transporting layer and the first electron-transporting layer and the second electron-transporting layer are arranged sequentially in this order from the light-emitting layer side to the cathode side. The first electron-transporting layer contains an indole derivative in which the ring nitrogen atom is substituted with an aromatic group and an aromatic ring is fused to the indole ring.
    Type: Grant
    Filed: February 27, 2009
    Date of Patent: June 24, 2014
    Assignee: Nippon Steel & Sumikin Chemical Co., Ltd.
    Inventors: Takayuki Fukumatsu, Toshihiro Yamamoto, Katsuhide Noguchi, Ikumi Ichihashi
  • Publication number: 20110101319
    Abstract: Provided are a hole-injecting material for an organic electroluminescent device (organic EL device) exhibiting high luminous efficiency at a low voltage and having greatly improved driving stability, and an organic EL device using the material. The hole-injecting material for an organic EL device is selected from benzenehexacarboxylic acid anhydrides, benzenehexacarboxylic acid imides, or N-substituted benzenehexacarboxylic acid imides. Further, the organic EL device has at least one light-emitting layer and at least one hole-injecting layer between an anode and a cathode arranged opposite to each other, and includes the above-mentioned hole-injecting material for an organic EL device in the hole-injecting layer. The organic EL device may contain a hole-transporting material having an ionization potential (IP) of 6.0 eV or less in the hole-injecting layer or a layer adjacent to the hole-injecting layer.
    Type: Application
    Filed: February 27, 2009
    Publication date: May 5, 2011
    Applicants: Nippon Steel Chemical Co., Ltd., Yamagata Promotional Organization for Industrial Technology
    Inventors: Takayuki Fukumatsu, Ikumi Ichihashi, Hiroshi Miyazaki, Atsushi Oda