Many in the automotive lighting community may not know that the Laboratory for Lighting Technology at TU Darmstadt is the most-involved lab for non-automotive lighting with LEDs in Europe. This includes street light and indoor lighting with LEDs.
Frequently Prof. Dr.-Ing.-habil. Tran Quoc Khanh gives lectures for this other field. It has many developments similar to the automotive lighting area. Street lighting and car front lighting share the roadway lighting task. But we have a 70-year disconnect and a thick border between the two communities. Why?
Here is an extract of an interesting research work performed in the field of general lighting under the responsibility of Prof. Dr.-Ing.-habil. Tran Quoc Khanh.
Aspects of lighting quality and energy efficiency
At the moment, we do not have a useable definition on the term “lighting quality“.
We should use this term as a sum of light quality and illumination quality.
– Light quality should come from the spectral distribution of the light sources, their colour properties and circadian behaviour.
– Illumination quality contains the aspects of luminance and illuminance distribution, the direction of the coming light and glare.
Up to now, the widely used quantity of energy efficiency has been luminous efficacy in lm/W. However, a better quantity would be “luminance or illumination efficacy“ in Lx/W underlining how many electrical power is needed in order to solve an illumination task fulfilling the international or national lighting standards requirements.
LED-Technology and its optimal use for energy efficiency