Patents by Inventor Ryou Ishikawa

Ryou Ishikawa 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).

  • Sound outputting devices using digital displacement data for a PWM sound signal
    Patent number: 5408583
    Abstract: Sound information is binarized by delta modulation or adaptive delta modulation. The resulting data is subjected to pulse wide modulation and the resulting data is delivered to a reproducing device, which detects a leading edge of a received signal pulse to produce a self operation timing clock to thereby reproduce a sound. When the reproducing device detects the absence of edges for a predetermined interval after the edge detection, it turns off a power source for an analog circuit to suppress power consumption.
    Type: Grant
    Filed: July 14, 1992
    Date of Patent: April 18, 1995
    Assignee: Casio Computer Co., Ltd.
    Inventors: Kazuyoshi Watanabe, Ryou Ishikawa