The goal of the investigations was to find out if there is a correlation between the luminance distribution on the lens surface of projection type headlamps (e.g. maximum luminance) and the average subjective glare rating (discomfort glare) of subjects under night time traffic conditions. The luminance distributions of different projection type systems are measured with a luminance measurement system and compared concerning their characteristics. For the validation a glare rating experiment has ben carried out with a standard type glare source of different size and luminance peaks similar to projection lens luminances. It was found out that for glare peaks up to a diameter of alpha = 2' (observation angle) the candle power of the glare source is the proper parameter to calculate the subjective glare effect. For larger sizes of the glare sources there is a dependency to the diameter of the glare source for the glare effect. So it depends on the luminance distribution of the light emitting area if the candle power of the glare source is the right parameter to describe the glare effect. The results of the investigations show new aspects, which have to be considered in the field of new headlamp technologies. Not only for the design of conventional projection systems for headlamps low beam pattern, but fiber optic systems with several small lenses and the usage of diodes for lighting and signaling applications often use very small light emitting areas and therefore show high luminance peaks. For these devices the glare borderline between comfort and discomfort glare (BCD) has to be taken into account and the presented results show that the glare illuminance at the driver's eye position is not in each case the only important parameter. Areas of luminance show a special influence if the luminance peak area is smaller then alpha = 2' = 3,3x10-2 degree in diameter. In further investigations the influence of the adaptation level and the influence of an array (multiple glare sources) of such luminance peaks (e.g. diodes for rear signal lamps) has to be analysed.
New investigation of the subjective glare effect of projection type headlamps
Neue Untersuchung von subjektiven Blendeffekten bei Scheinwerfern des Projektionstyps
2004
7 Seiten, 12 Bilder, 3 Tabellen, 8 Quellen
Conference paper
English
New investigation of the subjective glare effect of projection type headlamps
Automotive engineering | 2004
|New Investigation of the Subjective Glare Effect of Projection Type Headlamps
SAE Technical Papers | 2004
|New Investigation of the Subjective Glare Effect of Projection Type Headlamps
British Library Conference Proceedings | 2004
|New Investigation of the Subjective Glare Effect of Projection Type Headlamps
British Library Conference Proceedings | 2004
|Disability and discomfort glare of headlamps
Tema Archive | 2009
|