中间视觉条件下汽车信号灯色漂移、照度和透雾率研究

Research on Color Shift,Illumination and the Fog Penetrability of Vehicle Signals in Mesopic Vision

为了比较起雾时中间视觉条件下以LED和钨丝灯为光源的汽车信号灯的色漂移、照度和透雾率,以5050贴片LED、晶圆芯片LED和钨丝灯为光源的红色和琥珀色信号灯为研究对象,在参考光源透雾率15%～85%的雾浓度范围内,在暗箱内用光谱仪测量不同雾浓度下各信号灯的光谱,再计算色坐标、照度和透雾率,然后进行比较。研究结果表明:钨丝灯色漂移大于LED灯,汽车信号灯在不同雾浓度下色坐标沿着斜率为-1的直线漂移。中间视觉下,不同光源信号灯照度均随着亮度的降低而减小,LED灯减小的幅度大于钨丝灯。在亮度水平0.1～2cdm2范围内,汽车信号灯透雾率变化小于2%,在任意雾浓度下,5050贴片LED透雾率最佳,钨丝灯透雾率次之,晶圆芯片LED透雾率最差。该研究对设计与检测汽车信号灯具、提高行车安全有重要意义。

The color shift, illuminance and transmittance through fog among tungsten filament lamps and LED lamps which are used for vehicle signals were analyzed and compared in mesopie vision region. The spectra of LED and tungsten filament lamp were measured with a spectrometer in a dark box at the reference fog penetrability from 15% to 85%. Then the color coordinate, illuminance and the change of fog penetrability were obtained by calculation of the spectra. It is shown that the color shift of tungsten lamps is larger than LED lamps. The color coordinate of all vehicle signals in fog shift along a straight line with a slope of - 1. The illuminace decreases with the decrease of brightness in mesopic vision, and the illuminaee of LEDs decreases faster than that of tungsten filament lamps. The variation of the transmittance through fog of all vehele signals are less than 2% between 0. 1 and 2ed/m2. The transmittance through fog of SMD LED is the highest while that of wafer LED is the lowest. This research is very important for the design and test of vehicle signals and the safety of road traffic.