Patents by Inventor Yuuji Kumagai

Yuuji Kumagai 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).

  • Image forming apparatus
    Patent number: 8219004
    Abstract: An image forming apparatus including: a first and a second photoconductor groups constituted of one or more photoconductors respectively; a first and a second drive control sections for controlling the drive of the first and the second photoconductor groups respectively to rotate the photoconductors thereof, wherein the rotational phases of the first photoconductor group and the second photoconductor group are adjusted to be matched therebetween; and the first and the second drive control sections control so that predetermined profile of a target speed is applied to the first and second photoconductor groups wherein, in the target-speed profile, the first photoconductor group starts rotating after a elapse of a predetermined startup delay time from the second photoconductor group starts rotating, and both groups end at a same final speed predetermined for full-color image formation, wherein the startup delay time is predetermined based on measurements of times needed for each of the first and the second photo
    Type: Grant
    Filed: June 11, 2009
    Date of Patent: July 10, 2012
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Shuichi Mochizuki, Tetsushi Ito, Hirotsugu Akamatsu, Kiyoshi Sasoh, Yuuji Kumagai, Tetsuya Yamaguchi
  • Image forming apparatus
    Publication number: 20090311007
    Abstract: An image forming apparatus including: a first and a second photoconductor groups constituted of one or more photoconductors respectively; a first and a second drive control sections for controlling the drive of the first and the second photoconductor groups respectively to rotate the photoconductors thereof, wherein the rotational phases of the first photoconductor group and the second photoconductor group are adjusted to be matched therebetween; and the first and the second drive control sections control so that predetermined profile of a target speed is applied to the first and second photoconductor groups wherein, in the target-speed profile, the first photoconductor group starts rotating after a elapse of a predetermined startup delay time from the second photoconductor group starts rotating, and both groups end at a same final speed predetermined for full-color image formation, wherein the startup delay time is predetermined based on measurements of times needed for each of the first and the second photo
    Type: Application
    Filed: June 11, 2009
    Publication date: December 17, 2009
    Applicant: Sharp Kabushiki Kaisha
    Inventors: Shuichi Mochizuki, Tetsushi Ito, Hirotsugu Akamatsu, Kiyoshi Sasoh, Yuuji Kumagai, Tetsuya Yamaguchi