Patents by Inventor Toshiaki Koyama

Toshiaki Koyama 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: 5532652
    Abstract: An oscillation circuit in which the driving performance of a CMOS transistor therein for enabling/disabling an oscillating function is enhanced without unstabilizing the oscillation operation, by applying a higher potential to the back gate of the CMOS transistor when a signal other than an oscillation signal is inputted/outputted, and a lower potential when generating the oscillation signal.
    Type: Grant
    Filed: March 3, 1995
    Date of Patent: July 2, 1996
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Toshiaki Koyama, Shinichi Hirose, Hisashi Harada
  • Patent number: 5434863
    Abstract: An internetworking apparatus which handles a scale of a network flexibly without degrading high speed operation. A router manager and a plurality of routing accelerator modules for performing routing are connected to one another through a high speed bus, and a plurality of communication ports are connected to the respective routing accelerators independently of one another. The plurality of routing accelerators can perform the routing for reception data packet at high speed. If more routing accelerators are provided, the disposal to the networks having a small scale to a large scale can be readily realized.
    Type: Grant
    Filed: August 27, 1992
    Date of Patent: July 18, 1995
    Assignee: Hitachi, Ltd.
    Inventors: Katsuyoshi Onishi, Naoya Ikeda, Osamu Takada, Toshiaki Koyama, Hiromichi Enomoto
  • Patent number: 5211031
    Abstract: A scroll type compressor having a pair of scroll type compression units which are encased in the same casing so as to make a common use of a lubricating oil reservoir provided in the casing, wherein the compression units have compression elements, drive shafts, driving motors and other components which are of the same constructions and specifications, and wherein each of the compression units are adapted to be driven selectively by commercial electrical power or through a frequency-variable inverter so as to operate at different speeds. Since both compression units can be made up from the same components such as the compression elements, loads in the production, service and administration, are greatly reduced contributing to a reduction in the labor and cost, while eliminating any mounting error.
    Type: Grant
    Filed: May 22, 1991
    Date of Patent: May 18, 1993
    Assignee: Hitachi, Ltd.
    Inventors: Akira Murayama, Tadashi Fukuishi, Sigeaki Kuroda, Toshiaki Koyama, Tadao Ochiai, Toshio Hirai, Shintaro Sado, Yasushi Izunaga, Shouji Kikuchi, Fumio Yoshinaga
  • Patent number: 4849962
    Abstract: In communications control unit for sequentially scanning a plurality of line sets to which full-duplex lines are connected, for reading out line control word provided in correspondence to the line from a memory when a data transmission/reception request exists in the line set, and for executing the data transmitting and receiving operations with the relevant line set, one line control word including both of transmission control information and reception control information is read out in the time slot assigned to one full-duplex line, and the data transmitting and receiving operations are simultaneously executed.
    Type: Grant
    Filed: February 8, 1988
    Date of Patent: July 18, 1989
    Assignee: Hitachi, Ltd.
    Inventors: Shigeki Morimoto, Toshiaki Koyama