Patents by Inventor Yoshikazu Fukuhara

Yoshikazu Fukuhara 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).

  • Digital PLL device and digital PBX using the same
    Patent number: 6968027
    Abstract: A digital PLL device in accordance with the present invention comprises a selector for selecting one of a first synchronous timing signal and a second synchronous timing signal, and a comparator for outputting a phase correction value corresponding to phase difference between the synchronous timing signal selected by the selector and an internal synchronous timing signal. The digital PLL device stores the phase correction value from the comparator at a stable operation. The digital PLL device also performs a hold over operation accompanied by high accurate phase correction based on the phase correction value, since a fault occurs in the first synchronous timing signal until the timing signal is switched to the second synchronous timing signal.
    Type: Grant
    Filed: June 7, 2001
    Date of Patent: November 22, 2005
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventor: Yoshikazu Fukuhara
  • Digital PLL device and digital PBX using the same
    Publication number: 20020027966
    Abstract: A digital PLL device in accordance with the present invention comprises a selector for selecting one of a first synchronous timing signal and a second synchronous timing signal, and a comparator for outputting a phase correction value corresponding to phase difference between the synchronous timing signal selected by the selector and an internal synchronous timing signal. The digital PLL device stores the phase correction value from the comparator at a stable operation. The digital PLL device also performs a hold over operation accompanied by high accurate phase correction based on the phase correction value, since a fault occurs in the first synchronous timing signal until the timing signal is switched to the second synchronous timing signal.
    Type: Application
    Filed: June 7, 2001
    Publication date: March 7, 2002
    Inventor: Yoshikazu Fukuhara