Patents by Inventor Yasuhiro Iwafuji

Yasuhiro Iwafuji 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: 5789850
    Abstract: A DC glow discharge lamp is disclosed, in which one the pinch seal portions of an arc tube of quartz glass with an anode and a cathode arranged therein in opposed relation to each other is bonded to a base by means of a ceramic adhesive containing a binder, and a conductive member connected around the cathode-side pinch seal portion is mounted in such a manner as to assume the same potential as the cathode. Even in the case where the binder mixed in the ceramic adhesive for improving the bonding strength is vaporized, it attaches to the conductive member and assumes a negative potential and thus is prevented from attaching to the cathode-side pinch seal portion. The devitrification of the pinch seal portion or the leakage therefrom which otherwise might occur due to the binder are thus suppressed, thereby providing a DC glow discharge lamp with an improved service life.
    Type: Grant
    Filed: February 13, 1997
    Date of Patent: August 4, 1998
    Assignee: Toshiba Lighting & Technology Corporation
    Inventors: Yasuhiro Iwafuji, Hiromichi Kawashima, Ichiro Tanaka, Mamoru Furuya, Nanao Murase
  • Patent number: 4988918
    Abstract: Arc discharged by a short arc discharge lamp can be made so small in diameter as to appear like a spot. Therefore, the illuminance efficiency of the short arc discharge lamp can be made high and its brightness can also be enhanced.
    Type: Grant
    Filed: June 21, 1989
    Date of Patent: January 29, 1991
    Assignee: Toshiba Lighting and Technology Corporation
    Inventors: Yasuki Mori, Yasuhiro Iwafuji, Yoichiro Mitsuyuki, Tadatoshi Higashi