Patents by Inventor Tatuo Yonezawa

Tatuo Yonezawa 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: 4524351
    Abstract: In a smoke detector of the type in which smoke is detected in a detection chamber based upon a variation of an ionization current flowing therein or a variation of light beam passing therethrough, there is provided a reference signal generating section which produces a reference signal having a predetermined characteristic corresponding to typical smoke flowing into the detection chamber when a fire occurs, and a signal comparison section which compares a detection signal detected in the detection chamber with the reference signal, wherein a smoke sensing signal is produced when the detection signal is determined as a signal due to a fire but is not produced when the detection signal is determined as the signal due to the entry of an insect into the detection chamber or due to cigarette's smoke flowing thereinto.
    Type: Grant
    Filed: August 13, 1982
    Date of Patent: June 18, 1985
    Assignee: Nittan Company, Limited
    Inventors: Tetsuo Kimura, Hirofumi Fujii, Hayami Yuasa, Tatuo Yonezawa