Patents by Inventor Fumio Narusawa

Fumio Narusawa 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).

  • Photodetector having a control block for maintaining a detection signal within a predetermined tolerance range
    Patent number: 6570149
    Abstract: There is disclosed a photodetector which is capable of attaining an enhanced detection accuracy, and at the same time permits reduction in the size and manufacturing costs thereof. An avalanche photodiode detects an incident light, in a state of a predetermined bias voltage set thereto. A cooler cools the avalanche photodiode to a predetermined cooling temperature. An amount of an incident signal light incident on the avalanche photodiode is detected based on a detection signal from the avalanche photodiode. A control block adjusts at least one of the bias voltage and the predetermined cooling temperature, thereby holding a value of the detection signal from the avalanche photodiode generated in a state of the incident light being blocked from impinging on the avalanche photodiode, within a predetermined tolerance range.
    Type: Grant
    Filed: March 21, 2001
    Date of Patent: May 27, 2003
    Assignee: Hioki Denki Kabushiki Kaisha
    Inventors: Tomoyuki Maruyama, Makoto Kudo, Fumio Narusawa
  • Photodetector
    Publication number: 20010023944
    Abstract: There is disclosed a photodetector which is capable of attaining an enhanced detection accuracy, and at the same time permits reduction in the size and manufacturing costs thereof. An avalanche photodiode detects an incident light, in a state of a predetermined bias voltage set thereto. A cooler cools the avalanche photodiode to a predetermined cooling temperature. An amount of an incident signal light incident on the avalanche photodiode is detected based on a detection signal from the avalanche photodiode. A control block adjusts at least one of the bias voltage and the predetermined cooling temperature, thereby holding a value of the detection signal from the avalanche photodiode generated in a state of the incident light being blocked from impinging on the avalanche photodiode, within a predetermined tolerance range.
    Type: Application
    Filed: March 21, 2001
    Publication date: September 27, 2001
    Applicant: Hioki Denki Kabushiki Kaisha
    Inventors: Tomoyuki Maruyama, Makoto Kudo, Fumio Narusawa