New Calculation Method of Blue Light Hazard of Luminaires

Abstract

White LED is usually excited by blue light. With the wide use of LED table lamp, people pay more and more attention to the blue light hazard of luminaires. In fact, blue light is an indispensable part of white light, it harms to the retina of human eyes only when the blue light irradiation exceeds a certain limit. The problem is how to know the value of blue light hazard of a luminaire. Generally, the blue light hazard can be measured, but the measurement is very complex and the measure cost is very high. A theoretical method for calculating the blue light hazard was provided in this paper. That is, fitting the spectrum of the lamp with a spline function, then obtaining the function expression of lamp brightness. At the same time, another spline function is used to get the weight function expression of blue light hazard by fitting the data listed in IEC/EN62471. Then a blue light hazard function was defined with the wavelength as independent variable, and calculate the blue light hazard value by integrating this function. In this way, as long as the absolute light power spectrum of a luminaire is known, the quantitative blue light hazard value then can be directly obtained without measurement. This provides a convenient method to evaluate and analyze the safety level of lamps in advance. In this paper, taking two lamps as examples, which belong to IEC / EN62471 safety level RG0 and RG1 respectively, the blue light irradiation values of the lamps are obtained by using a mathematical platform. It is very consistent with the calculation results. In this way, the numerical values of blue light hazard can be obtained by mathematical calculations, which undoubtedly provide an optional method to solve the light biosafety assessment of LED lamps.