2003 Volume 87 Issue 5 Pages 299-303
This paper describes a new-structure luminaire system with a xenon discharge lamp and a liquid crystal filter, that controls color temperature of illuminating light widely and continuously according to the voltage applied to the filter. We designed and fabricated a new optical filter by laminating two different types of liquid crystal devices, that individually decrease and increase color temperature of transmitted light by varying the spectral balance of incident light from the discharge lamp. Each liquid crystal device contains different dichroic dyes and absorbs short-or long-wavelength visible light. The degree of absorption can be varied by controlling the applied voltage. From the fundamental optical experiments, in which a high-pressure xenon discharge lamp of neutral color temperature of 5600K with almost flat radiation spectrum was combined with the liquid crystal filter mentioned above, we found that the color temperature of light radiated from the system can be varied from 3800K to 8200K. The presented luminaire system is especially useful for capturing video and photographic images and for appreciating art works when strict color temperature control is essential.
