Research On Healthy Display Based On Emission Spectrum

With the quick development of the novel display technology,more types of display devices are widely spreading in the life of people.The quality requirement of people is not only limited by the color purity,color difference,luminance,and other visual performances,but also includes the non-visual parameters related to human health.Combing different primary colors with various spectral power densities would exert different non-visual effects on the human body,applicable in different display fields.Thus,the research on non-visual effect of display devices becomes meaningful for human health.This work compares different types of display devices as research objects and discusses related influence mechanisms,and includes the following aspects:(1)The visual and non-visual performances of different types of display are studied.This work mainly discusses the health of displays concluding quantum dots,lasers,and phosphors.The gaussian function is used to model the spectrum.The genetic algorithm is used to optimize the spectral combinations.The visual performances containing color gamut area,color difference,and luminous efficacy of radiation,are as limited conditions in the program of genetic algorithm.The highest and lowest circadian action factor are respectively calculated.The lowest circadian action factor is 0.215 for laser display,and the highest is 1.142.The circadian action factor tunability is introduced to evaluate the circadian tunable performance of multi primary LEDs,and the relationship between color gamut and circadian tunability is discussed.At last,how the full width at half maxima and peak wavelength affect the circadian action factor and color gamut is analyzed.(2)The influence mechanism of phosphor particle on healthy display is discussed.Via the simulation platform of LightTools,the model of three primary phosphor coated LED with chip-scale packaging is created.The phosphor particle is simply assumed as spheric shape.When the color point of display and white point of standard light source are kept within 0.015,the varying trend of circadian action factor with the change of particle size at the same phosphor concentration is analyzed.When the particle diameter is in the micro level,the circadian action factor increases as the diameter increases.While the particle diameter is in the sub-micro level,the circadian action factor increases first and then decays as the diameter increases.The change of circadian action factor is explained by Mie scattering theory,scattering intensity distribution,and hyper spectral imaging data.