Patents by Inventor Minouru Yoshii

Minouru Yoshii 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).

  • Phase shift device and laser apparatus utilizing the same
    Patent number: 5477554
    Abstract: A phase shift device for a laser beam has a circular first area transparent so the laser beam and a second area provided around the first area and transparent to the laser beam. The first and second areas generate a phase difference for example 180.degree. in the passing light beams. The phase shift device is positioned for example at a beam waist of a laser scanning apparatus to form a beam spot of a diameter smaller than that defined by the numerical aperture of the imaging optical system. Structure of a laser apparatus employing such phase shift device is also disclosed.
    Type: Grant
    Filed: February 23, 1995
    Date of Patent: December 19, 1995
    Assignee: Canon Kabushiki Kaisha
    Inventors: Minouru Yoshii, Kenji Saito, Masayuki Suzuki, Hiroshi Osawa