Patents Examined by Nimeskumar Patel
  • Patent number: 5723947
    Abstract: An electrodeless inductively-coupled fluorescent lamp which operates at ro frequency comprising a bulbous envelope (1) filled with rare gas and metal vapor. A reentrant cavity (4) and an induction coil (6) are disposed in the cavity (4). The inner walls of the envelope (1) and the cavity (4) have a protective coating (3) and a phosphor coating (2). A metal Faraday cylinder (12) welded to the lamp base (13) is disposed between the cavity (4) and the coil (6) to reduce capacitive RF voltage between the coil and the plasma to improve lamp maintenance and remove heat. A tubulation (16) is disposed on the lamp axis to evacuate the envelope (1). The proximal end of the tubulation (16) has an expansion (20) with the volume (23) where the initial capacitive discharge is ignited.
    Type: Grant
    Filed: December 20, 1996
    Date of Patent: March 3, 1998
    Assignee: Matsushita Electric Works Research & Development Laboratories Inc.
    Inventors: Oleg Popov, Jakob Maya, Koichi Kobayashi, Edward K. Shapiro