Patents by Inventor Yukinobu Hara

Yukinobu Hara 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).

  • Process for production of pure transparent quartz
    Patent number: 5665133
    Abstract: Pure transparent quartz glass is provided by molding powdery amorphous silica into an article, converting the molded powdery amorphous silica into crystalline silica of high-temperature type cristobalite structure, and then fusing the crystalline silica, the quartz glass containing impurities respectively at a content of not higher than 1 ppm, and an OH group at a content of not higher than 20 ppm, and having a viscosity of 10.sup.12.0 poise or more at 1200.degree. C. The quartz glass is transparent and has high purity, and is excellent in high temperature viscosity characteristics. The quartz glass can be produced at a low cost.
    Type: Grant
    Filed: October 10, 1995
    Date of Patent: September 9, 1997
    Assignees: Tosoh Corporation, Nippon Silica Glass Co., Ltd.
    Inventors: Koichi Orii, Yukinobu Hara, Tomoyuki Akiyama, Koji Tsukuma, Yoshikazu Kikuchi