Patents by Inventor Hirofumi Sumoto

Hirofumi Sumoto 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).

  • Fluorescent lamp having ultraviolet reflecting layer
    Patent number: 5008789
    Abstract: A fluorescent lamp of this invention includes an ultraviolet reflecting layer of a nonemission material essentially consisting of .alpha.-alumina, and a light-emitting layer. The nonemission material is a white powder having an average grain size of 0.05 .mu.m to 2 .mu.m. The light-emitting layer is formed on the discharge generation region side of the ultraviolet reflecting layer. According to this invention, ultraviolet ray having passed through the light-emitting layer without being absorbed therein are reflected by the ultraviolet reflecting layer and are radiated onto the light-emitting layer again. For this reason, the light-emitting layer is more frequently excited with the ultraviolet rays to increase a luminous flux.
    Type: Grant
    Filed: February 14, 1990
    Date of Patent: April 16, 1991
    Assignee: Nichia Kagaku Kogyo K.K.
    Inventors: Kiyotaka Arai, Hirofumi Sumoto, Keizi Ichinomiya