Patents by Inventor Akemi Yamanaka

Akemi Yamanaka 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).

  • Semiconductor laser device having little astigmatism
    Patent number: 4780879
    Abstract: A semiconductor laser device having a stripe-shaped active region defined between a pair of end surfaces, at least one of the end surfaces having a curved cross-section in a plane parallel to the active region with a radius of curvature from 10 to 300 .mu.m, the stripe of the active region having such a width that a single transverse mode and a multi-longitudinal mode are allowed. The laser beam emitted from this laser can have little astigmatism and small spot size.
    Type: Grant
    Filed: February 19, 1987
    Date of Patent: October 25, 1988
    Assignee: Hitachi, Ltd.
    Inventors: Naoki Chinone, Shigeo Yamashita, Shin'ichi Nakatsuka, Akemi Yamanaka, Yuichi Ono, Toshihiro Kawano, Kazuhisa Uomi, Takashi Kajimura, Toshiaki Tanaka, Kunio Aiki