Patents by Inventor Takashi Suen. A

Takashi Suen. A 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: 5149659
    Abstract: The concentration of molecular fluorine in a mixed gas such as an excimer laser gas can be determined easily, quickly and accurately by passing the mixed gas through a column packed with an alkali metal or alkaline earth metal compound which has no halogen atom and reacts with fluorine to form a solid fluoride together with molecular oxygen and/or carbon dioxide and measuring the concentration of oxygen or carbon dioxide in the fluorine-free gas flowed out of the packed column. If the mixed gas initially contains molecular oxygen or carbon dioxide, its concentration is measured separately after fixing fluorine in another column packed with an element which forms a fluoride. This analyzing method can be used in a feedback control system for controlling the concentration of fluorine in an excimer laser gas during operation of the laser to thereby stabilize the laser output power.
    Type: Grant
    Filed: March 5, 1991
    Date of Patent: September 22, 1992
    Assignee: Central Glass Company, Limited
    Inventors: Kohzo Hakuta, Minoru Aramaki, Takashi Suen. A, Mitsuo Kodama, Hisaji Nakano, Shinsuke Nakagawa