Patents by Inventor Hiroyoshi Yajima

Hiroyoshi Yajima 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).

  • Divided electrode type semiconductor laser device
    Patent number: 5018159
    Abstract: Disclosed is a divided electrode type semiconductor layer device designed to improve the separation of electrodes without reducing the amount of doping for carrier injection layers. A double-hetero-structure is formed on a semi-insulating substrate, and at least two pairs of carrier injection clad layers are thereafter buried like lands while a high-resistance portion is left between the carrier injection clad layers to electrically separate these layers. The electrodes are respectively formed on the separated carrier injection layers.
    Type: Grant
    Filed: November 22, 1989
    Date of Patent: May 21, 1991
    Assignees: Director-General, Agency of Industrial Science and Technology, Mitsubishi Kasei Corporation
    Inventors: Yoshihiro Suzuki, Hiroyoshi Yajima, Junichi Shimada, Kenji Shimoyama, Hideki Gotoh