Evaluating tradeoffs between energy efficiency and color rendition

Royer, Michael P.

doi:10.1364/osac.2.002308

Cited by 20 publications

(24 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The tradeoff between Rf (or Ra) and luminous efficacy of radiation is well documented (Royer, 2019c, David et al, 2015, Zhang et al, 2017b, Papamichael, K. et al, 2016. Figure 3 shows the compounding tradeoff between luminous efficacy of radiation and the combination of Rf and Rt.…”

Section: Spectral Efficacymentioning

confidence: 87%

“…An additional 50,000 four-primary SPDs with mixed FWHM characteristics were also included, as were approximately 15,000 other randomly generated SPDs with similar constraints that were used in a previous analysis (David et al, 2019). The total set of approximately 165,000 theoretical SPDs was used in a previous analysis of energy efficiency tradeoffs with various measures of colour rendition (Royer, 2019c), where it is described further, and is available for download (Royer, 2019d, Royer, 2019b.…”

Section: Methodsmentioning

confidence: 99%

“…Four-primary SPDs optimized for maximum luminous efficacy of radiation were previously generated under a variety of constraints on both colour rendition characteristics (e.g., Rf, Ra, etc.) and spectral characteristics (peak wavelength and FWHM ranges) (Royer, 2019c). These included theoretical spectral characteristics allowing FWHM as narrow as 1 nm with Duv as high as 0.006, and realistic spectral characteristics that varied by peak wavelength according to existing capabilities (e.g., 15 nm minimum FWHM for primaries less than 490 nm) and with Duv as high as 0.000.…”

Section: Methodsmentioning

confidence: 99%

“…A related consideration involves spectral optimization for colour preference rather than colour fidelity. This allows higher maximum luminous efficacy of radiation values (Royer, 2019c), principally due to reduced requirements for average colour fidelity (e.g., Rf). However, such optimized SPDs have Rt values between 83 and 85, which is at or below the level for "80 Series" triphosphor fluorescent lamps.…”

Section: Implications For Future Light Source Developmentmentioning

confidence: 99%

See 3 more Smart Citations

Spectral Characteristics Influencing the Metameric Uncertainty Index

Royer

Whitehead

2019

PROCEEDINGS OF the 29th Quadrennial Session of the CIE

Self Cite

View full text Add to dashboard Cite

This article examines the relationship between various attributes of light source spectral power distributions (SPDs) and a recently proposed measure of colour rendition, the Metameric Uncertainty Index (Rt). For SPDs comprised of discrete spectral emissions (primaries), the maximum achievable Rt value (corresponding to a reduced likelihood of metameric mismatch) increases with both the number of primaries and their bandwidth. This work also explores how Rt relates to and interacts with other measures of colour rendition-in particular, the Fidelity Index (Rf)-and luminous efficacy of radiation (k). This is important, because there is an intrinsic tradeoff between luminous efficacy of radiation and colour rendition, which informs the application-dependent optimization of illumination. When whitelight SPDs are engineered to maximize k, subject to maintaining a minimum required Rf value, the result is a small number of narrow primaries and hence a comparatively poor Rt value. This can only be mitigated by including Rt among the colour rendition optimization constraints. Therefore, from this perspective, Rt is an independent and key aspect of colour rendition.

show abstract

Section: Spectral Efficacymentioning

confidence: 87%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Implications For Future Light Source Developmentmentioning

confidence: 99%

See 2 more Smart Citations

Spectral Characteristics Influencing the Metameric Uncertainty Index

Royer

Whitehead

2019

PROCEEDINGS OF the 29th Quadrennial Session of the CIE

Self Cite

View full text Add to dashboard Cite

show abstract

“…The LED clusters proposed in other works [22][23][24] have their advantages and disadvantages; however, most of the reported solutions cannot be considered as optimal in terms of high CRI and efficacy in a wide range of CCTs. To solve this problem, research activities are focused on development of new types of phosphors, study of the effect of quantum dots usage, 31 creation of sophisticated algorithms for determining the LEDs contributions based on the fidelity-luminous efficacy of radiation (LER) Pareto boundaries, 26,32 and other improvements such as applications that utilized more than 10-component systems. 27,33 However, despite many advances in lighting technology, a simple algorithm is needed to determine the components contributions ratio in lighting systems using a typical set of LEDs with the primary colors, to escape complex computational algorithms and implementation of special nontypical components.…”

Section: Introductionmentioning

confidence: 99%

Red, green, blue, and white clusters for daylight reproduction

et al. 2020

View full text Add to dashboard Cite

Daylight is an inherent attribute of a sustainable building. Artificial reproduction of natural illumination under varying needs and environmental conditions has been made possible after the appearance of the new wave of solid-state light sources. Our work is devoted to the development of white light-emitting diode (LED) clusters consisting of red, green, blue, and white (RGBW) LEDs for implementation in a smart lighting system that is able to reproduce light with correlated color temperature (CCT) similar to daylight, high values of color rendering index, and luminous efficacy. A method for determination of the optimal contribution of each of the four LEDs is demonstrated and discussed. We show that only three LEDs-green, blue, and white (no red) can be used in many cases for reproducing daylight. Both luminous efficacy of radiation and actual luminous efficacy of the considered RGBW clusters as functions of the CCT are analyzed.

show abstract