Patents by Inventor Mizuho Hiraoki

Mizuho Hiraoki 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).

  • Spiro compound and organic luminescence device using the same
    Patent number: 7510781
    Abstract: Provided are a novel spiro compound, and an organic luminescence device using the spiro compound and having an optical output with an extremely high efficiency and a high luminance, and an extremely high durability. The Spiro compound is represented by the following general formula [I]: (wherein R1, R2, R3, and R4 represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted amino group, a cyano group, or a halogen atom, and R1, R2, R3, and R4 may be identical or different from each other; and Ar1 and Ar2 represent a substituted or unsubstituted condensed polycyclic aromatic group or a substituted or unsubstituted condensed polycyclic heterocyclic group, which may be identical or different from each other.
    Type: Grant
    Filed: August 12, 2003
    Date of Patent: March 31, 2009
    Assignee: Canon Kabushiki Kaisha
    Inventors: Koichi Suzuki, Mizuho Hiraoki, Akihiro Senoo, Naoki Yamada, Chika Negishi, Akihito Saito