Patents by Inventor Kumi Kojima

Kumi Kojima 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: 20060246318
    Abstract: The present invention provides an evaluation method for evaluating whether a light-emitting element material to be evaluated is suitable for a host material or a guest material. By carrying out a first step of measuring absorption intensity of a light-emitting element material and a second step of irradiating the light-emitting element material with light for a predetermined period of time, repeatedly; thereby a change in absorption intensity with time is evaluated so that whether the light-emitting material is suitable for a host material or a guest material can be distinguished. The light emitted to the light-emitting element material preferably has a wavelength component which is absorbed by a skeleton which contributes to excitation of the light-emitting element material.
    Type: Application
    Filed: April 25, 2006
    Publication date: November 2, 2006
    Inventors: Ryoji Nomura, Satoshi Seo, Kumi Kojima, Nobuharu Ohsawa
  • Publication number: 20050260450
    Abstract: It is an object of the present invention to provide a luminescent material that has resistance to repeated oxidation reactions. Further, it is an object of the present invention to provide a light-emitting element that is high in luminous efficiency. Further, it is an object of the present invention to provide a light-emitting element that has a long life. An aspect of the present invention is an anthracene derivative represented by a general formula (1). In the general formula (1), R2 to R4 and R7 to R9 are individually any one of hydrogen, an alkyl group having 1 to 4 carbon atoms, and a group represented by the following structure formula (2), and R1, R5, R6, and R10 are individually any one of hydrogen and an alkyl group having 1 to 4 carbon atoms.
    Type: Application
    Filed: May 2, 2005
    Publication date: November 24, 2005
    Applicant: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Sachiko Yamagata, Ryoji Nomura, Kumi Kojima, Satoshi Seo