Dynamic prediction of optical and chromatic performances for a light-emitting diode array based on a thermal-electrical-spectral model

Abstract

Light-emitting diode (LED) arrays have attracted increased attention in the area of high power intelligent automotive headlamps because of their superiority in disposing of the power limit of an individual LED package and controllably luminous intensity and illumination pattern. The optical and chromatic performances of an LED array do not equal to the sum of individual LED packages' performances, as the thermal interactions between individual LED packages can't be ignored in the actual application. This paper presents a thermal-electrical-spectral (TES) model to dynamically predict the optical and chromatic performances of the LED array. The thermal-electrical (TE) model considering the thermal coupling effect in the LED array is firstly proposed to predict the case temperature of each individual LED package, and the Spectral power distributions (SPDs) of individual LED package is then decomposed by the extended Asym2sig model to extract the spectral characteristic parameters. Finally, the experimental measurements of the designed LED arrays operated under usage conditions are used to verify the TES model. Some validation case studies show that the prediction accuracy of the proposed TES model, which is expressed as a quadratic polynomial function of current and case temperature, can be achieved higher than 95%. Therefore, it can be concluded that this TES model offers a convenient method with high accuracy to dynamically predict the optical and chromatic performances of LED arrays at real usages.

Advancements in Spectral Power Distribution Modeling of Light-Emitting Diodes

“…It should be noted, that two varying Pearson type VII models were found in the literature. Therefor, both implementation by Reifegerste et al [4] and LMFIT built-in [19] [4], [5], [9], [10], [16], [21] Logistic Power Peak A, λp, σ S ∈ [10 −15 , 100]…”

Color Tuning for Perovskite Light-Emitting Diodes

“…The LED testing platform used in our lab compromises an integrating sphere, a spectrometer, a power supply, and a computer, as illustrated in Figure 3 3 Schematic illustration of the LED testing platform. [84]…”

Two-Dimensional Transient Temperature Distribution Measurement of GaN Light-Emitting Diode Using High Speed Camera

“…The emissivity in the TI measurement is also hard to be accurately determined for various materials in GaN LED, such as the cathodes and anodes. Other reported methods like the forward voltage [5], [6], centroid wavelength [7], peak wavelength [8], full width at half maximum [9], normalized emission power [10], blue-white ratio [11], Raman spectroscopy [12], [13], bi-directional thermal resistance [14], Micro-infrared Imaging [15], etc., are generally adopted to measure the average junction temperature of GaN-based LED. Recently, our research group has carried out several studies about measuring 2D surface temperature of GaN LED based on the hyperspectral imaging technology [7], [16].…”