Matsushita Electric Works, Ltd.

Taku Sumitomo

Atsunori Okada

Shin Ukegawa

Shigeaki Wada

Shinichi Aoki

Miki Kotani

Shingo Higashisaka

Koji Nishioka

Osamu Kuramitu

Naoki Saito

High-pressure sodium vapor lamp with high color rendering including, in an arc tube of a light transmitting material formed in a substantially cylindrical shape sealed hermetically at both axial ends, a pair of electrodes disposed internally at both axial ends of the tube and xenon gas of at least 2.5.times.10.sup.4 (Pa) sealed in the tube together with sodium vapor, is so constituted that a lamp voltage upon lighting of the lamp and represented by V (V as a unit), lamp power represented by W (watt), internal diameter of the arc tube represented by .phi. (mm) and distance between the pair of electrodes represented by d (mm) will satisfy the following formulas:

High pressure sodium vapor lamp with high color rendering

An electrodeless discharge lamp includes a discharge gas sealed in a lamp tube. The discharge gas includes a halide of rare earth metal. An auxiliary electrode is disposed on or adjacent to an outer periphery wall of the lamp tube such that the auxiliary electrode is capacitively coupled to an interior space of the lamp tube. A main induction coil is wound around the lamp tube and receives power from a first high frequency power source. The auxiliary electrode receives power from a second high frequency power source. In operation, the electrodeless discharge lamp attains smooth lighting upon starting or restarting.

Electrodeless discharge lamp

Growing community of inventors

Osaka, Japan

Taku Sumitomo