Open AccessSpace of visual and circadian parameters of RGBW lighting systems
Author(s) -
Daria Kalustova,
Vasyl Kornaga,
A. Rybalochka,
Sergiy Valyukh
Publication year - 2020
Publication title -
svìtlotehnìka ta elektroenergetika
Language(s) - English
Resource type - Journals
eISSN - 2415-3923
pISSN - 2079-424X
DOI - 10.33042/2079-424x-2020-1-57-16-21
Subject(s) - illuminance , circadian rhythm , fidelity , stimulus (psychology) , computer science , optics , biology , telecommunications , psychology , physics , neuroscience , cognitive psychology
Due to the proven effect of light on humancircadian rhythms, nowadays researchers and developers oflighting systems (LS) concentrate on the non-visualparameters of light and methods of ensuring a safecomfortable light environment. This requires optimisation ofspectral power distribution (SPD). In this view the mostpromising and functional are RGBW systems due to theirability to change dynamically SPD and, hence, lightparameters. In this work we explore two RGBW (red-greenblue-white) systems with different white LEDs (warm whiteand neutral white) and the space of visual and non-visualparameters that they can ensure. Visual parameters arestudied in terms of colour rendering index, colour fidelityindex and visual corneal illuminance while non-visualparameters are studied in terms of circadian light, circadianstimulus and circadian action factor. These parameters arecalculated for different contribution of the components in acorrelated colour temperature (CCT) range of 2500 – 7000K.In addition, acceptable criterion of the colour fidelity indexabove 85 is used. It is shown that under this condition thecircadian action factor in the range of 0.33-0.98 can beobtained by changing the CCT and (or) colour fidelity index.Also an achievable area of the circadian stimulus versuscorneal illuminance space for RGBW systems is found. Itenables to choose optimal combination of CCT, circadianstimulus and corneal illuminance to provide the desired levelof circadian effect with sufficient visual comfort dependingon the daytime and field of system's implementation. Thisdata is useful for LS manufacturers and lighting designers tocreate a comfortable lighting environment.Keywords - RGBW colour mixing, tunable white light,circadian effect, colour rendering, colour fidelity index.