Patents by Inventor Mayumi Yokoyama

Mayumi Yokoyama 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: 6399257
    Abstract: A color filter manufacturing method comprises the steps of forming, on a substrate, a photosensitive layer that increases or develops hydrophilic property upon irradiation of light; exposing the photosensitive layer to light for patterning to form hydrophilic areas in which hydrophilic property is relatively high and non-hydrophilic areas in which hydrophilic property is lower than the hydrophilic areas; and applying a setting ink to the hydrophilic areas with an ink jet technique, thereby forming colored portions. A color filter includes at least a photosensitive layer formed on a substrate and having hydrophilic areas in which hydrophilic property is increased or developed upon irradiation of light, and colored portions formed on the hydrophilic areas of the photosensitive layer. A liquid crystal device is constructed by using the color filter. The color filter can be manufactured inexpensively with the reduced number of steps while satisfying requisite characteristics.
    Type: Grant
    Filed: March 3, 2000
    Date of Patent: June 4, 2002
    Assignee: Canon Kabushiki Kaisha
    Inventors: Katsuhiro Shirota, Akio Kashiwazaki, Koichiro Nakazawa, Masashi Hirose, Mayumi Yokoyama, Yoshihisa Yamashita
  • Patent number: 6248482
    Abstract: Provided is a novel ink which is suitable for producing a color filter by use of an ink-jet system. The ink comprises a pyrazolone dye of the general formula (I): wherein R1 and R2 are each independently a hydrogen atom, an OH group, a halogen atom, a linear or branched alkyl group having 1 to 5 carbon atoms, a nitro group, a CF3 group or an SO3(M1) group, where M1 is an alkali metal or NH4; both R3 and R4 are an SO3(M2) group, where M2 is an alkali metal or NH4.
    Type: Grant
    Filed: March 25, 1999
    Date of Patent: June 19, 2001
    Assignee: Canon Kabushiki Kaisha
    Inventors: Akio Kashiwazaki, Katsuhiro Shirota, Koichiro Nakazawa, Masashi Hirose, Mayumi Yokoyama, Yoshihisa Yamashita
  • Patent number: 6203604
    Abstract: A novel ink is provided which comprises a metal complex azopyrazolone dye and a xanthene dye. This ink is suitable for forming a color filter by an ink-jet system. A color filter, a liquid crystal panel, and a computer employing the ink are also provided. Further, a process for producing the color filter is provided.
    Type: Grant
    Filed: March 25, 1999
    Date of Patent: March 20, 2001
    Assignee: Canon Kabushiki Kaisha
    Inventors: Akio Kashiwazaki, Katsuhiro Shirota, Koichiro Nakazawa, Masashi Hirose, Mayumi Yokoyama, Yoshihisa Yamashita