Optical, thermal and run-up performance of reflector compact fluorescent lamp

Abstract

The optical, thermal and run-up characteristics of reflector compact fluorescent lamps are investigated to optimise lamp designs for performance improvements. The efficiency of the burner/reflector assembly is studied to reduce reflection and absorption losses. When the reflector shape is changed from parabolic to elliptical, the light output is increased as well as the luminous intensity on the central axis. Light intensity in the whole half-space can be further improved by reducing the reflective coating height. The thermal load on the plastic base and the ballast components are minimised using designs with a heat dissipation cover. The plastic base temperature can be reduced by 20–30℃ compared to that without any protection. The run-up time can be shortened by optimising the indium amount in the indium flag, the flag position, and the mercury composition in Bi-In-Hg amalgam. The indium amount and the indium flag position will influence the run-up time due to a different releasing velocity of mercury from the flag. A Hg composition of about 4.5% in the Bi-In-Hg amalgam is best to shorten the run-up time and get a high, stable light output.