Patents by Inventor Naotoshi Iwasawa

Naotoshi Iwasawa 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: 7280448
    Abstract: A positioning control device and method in which the relative position error in tracking is reduced by using the periodicity of position shift. The positioning control device comprises a position detecting unit for measuring the relative position error between the desired position of an objective member and a moving member, an adding unit for adding a position error signal output from the position detecting unit and a delay signal, a signal delay unit for outputting the delay signal which is obtained by delaying an output of the adding unit at a period corresponding to the position shift of the objective member, a drive unit for moving a moving member, and an inputting unit for inputting the signal of the sum of the position error signal and the delay signal to the drive unit and addition-inputting the delay signal to the drive unit through a filter having a predetermined frequency characteristic in a specific frequency range.
    Type: Grant
    Filed: February 5, 2002
    Date of Patent: October 9, 2007
    Assignee: Nec Corporation
    Inventors: Masashi Kubota, Sigeru Shimonou, Naotoshi Iwasawa
  • Publication number: 20040240339
    Abstract: A positioning control device and method in which the relative position error in tracking is reduced by using the periodicity of position shift. The positioning control device comprises a position detecting unit for measuring the relative position error between the desired position of an objective member and a moving member, an adding unit for adding a position error signal output from the position detecting unit and a delay signal, a signal delay unit for outputting the delay signal which is obtained by delaying an output of the adding unit at a period corresponding to the position shift of the objective member, a drive unit for moving a moving member, and an inputting unit for inputting the signal of the sum of the position error signal and the delay signal to the drive unit and addition-inputting the delay signal to the drive unit through a filter having a predetermined frequency characteristic in a specific frequency range.
    Type: Application
    Filed: July 31, 2003
    Publication date: December 2, 2004
    Inventors: Masashi Kubota, Sigeru Shimonou, Naotoshi Iwasawa