Patents by Inventor Junko Yoshikawa

Junko Yoshikawa 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).

  • Toner and image forming method
    Patent number: 6316157
    Abstract: A non-metallic black toner is disclosed. The toner has toner particles containing at least a binder resin, a carbon black and an organometallic compound, and an external additive. The toner particles contain 10 to 200 ppm of at least one kind of alkali metal element and at least one kind of organometallic compound. The toner particles further contain a polyester resin. The non-metallic black toner has a weight-average particle diameter of 4 to 11 &mgr;m, the following loss tangents tan &dgr; shown by dielectric loss factor ∈″/dielectric constant ∈′ at frequencies of 5×104 Hz and 105 Hz: tan &dgr; (5×104 Hz)≦0.0125 tan &dgr; (105 Hz)≦0.0105, a Carr's flowability index of 50 or more, and a Carr's floodability index of 65 or more. Also, an image forming method is disclose using the black toner.
    Type: Grant
    Filed: July 5, 2000
    Date of Patent: November 13, 2001
    Assignee: Canon Kabushiki Kaisha
    Inventors: Junko Yoshikawa, Kenji Okado, Masaaki Taya, Yushi Mikuriya, Kazumi Yoshizaki, Yasushi Katsuta, Kenichi Nakayama