A Fundamental Study to Investigate the Effectiveness of Flashing Light as Visual Signal

本文通过改变单色闪光灯的颜色、强度、闪光持续时间和背景亮度来测量单色闪光灯的有效强度，并将视觉实验得到的有效强度Ie与Blondel & Rey-Douglas公式计算的有效强度Is进行比较，当背景亮度为O[cd/m^2]，闪光强度为阈值水平时，当背景亮度为O[cd/m^2]时，当背景亮度为0 [cd/m^2]时，当在短时间内，Ie/Is基本上大于1，随着时间的延长，Ie/Is单调减小并逐渐接近1，当强度上升到低或中等水平时，Ie/Is在时间从100 μ s增加到6 μ s时减小一次，在6 ~ 50 μ s内增加。当背景亮度增加到1或10[cd/m^2]时，Ie/Is出现最小值和最大值的持续时间与视觉系统的反应时间有关，其中以白色闪光最短，其次是蓝色、黄色、绿色和红色。另外，对于短持续时间的闪光，红色闪光的有效强度最高，并且按照白色、黄色、绿色和蓝色的顺序变得较低。特别地，持续时间短于1[ms]的闪光具有比估计值高的有效强度，由于其亮度和显著性，作为视觉信号是上级的。

In this study, the effective intensity of a monochromatic flashing light was measured by changing color, intensity and flashing duration of a light, and background luminance.The effective intensity, Ie, which was obtained by visual experiment, was compared with calculated effective intensity, Is, by Blondel & Rey-Douglas's formula.When the background luminance is O[cd/m^2] and the intensity of the flash is at threshold level, the Ie/Is is substantially greater than 1 for the flash of short time duration.As the duration becomes longer, the Ie/Is decreases monotonously and gradually approaches 1.As the intensity rises to the low or medium level, the Ie/Is decreases once as the duration increases from 100[mus] to 6[ms], and increases within the duration of 6 to 50[ms]. For the duration over 50[ms], it decreases again and approaches 1 gradually.Therefore the time durations at which the Ie/Is takes minimum and maximum value exist.When the background luminance is raised to 1 or 10[cd/m^2], the Ie/Is takes minimum and maximum even at threshold level.These durations are related to the response time of the visual system, and are shortest for the white flash, followed by blue, yellow, green and red.In addition, for the flash of short duration, the effective intensity of the red flash is the highest, and becomes lower in the order of white, yellow, green and blue.In particular, the flash with duration of shorter than 1[ms], which has higher effective intensity than the estimated value, is superior as visual signal for its brightness and conspicuousness.