International Forum on Automotive Lighting(IFAL)


Effect of automotive lamps area on discomfort glare

Mitsuhiro Uchida1, Ryuji Ueki2, Shoko Kawanobe3*, Yasushi Kita4*, Takako Kimura-Minoda5*

Stanley Electric Co.,Ltd; Kanagawa, Japan

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With recent automotive lamps, signal lamps such as daytime running lamps (DRLs) and tail lamps are occupying larger spaces as stylistic elements; while on the other hand, headlamps, stop lamps, rear fog lamps and the like are frequently being designed to be smaller. It is thought that lamps requiring high brightness levels will continue their trend toward smaller automotive lamps sizes through the use of light sources such as lasers and light-emitting diodes (LEDs).

According to Sivak (1989) et al., headlamps area is expected to have some effect on discomfort glare. However, current headlamps are smaller than headlamps area considered by Sivak (1989) et al., and it is unclear as to whether further reductions in area would have an effect on discomfort glare. Moreover, the effect of red light on the signal lamps area and discomfort glare is also not apparent.

Therefore, in this study, using a headlamps and a rear fog lamps, we changed the lamp area in 4 levels and evaluated discomfort glare using white and red LED light sources. Moreover, in consideration of the actual conditions of rear fog lights, we evaluated visibility and discomfort glare outdoors under low-visibility (fog) conditions.

We found that automotive lamps area had no effect on discomfort glare for both light colors. Moreover, reducing the lamps area in a rear fog light under low-visibility (fog) conditions was found to produce no difference in visibility and discomfort glare evaluation values. These findings suggest that miniaturization of the automotive lamps size is thought to improve the degree of freedom of styling, without leading to an increase in discomfort glare.