ADDITIVITY OF GLARE SENSITIVITY USING LED LIGHTS AT MESOPIC BACKGROUND LIGHT LEVELS

摘要

Human vision at night is a complex phenomenon. Planning the proper light source for that condition is a grand challenge in these days. Vision at nighttime driving falls into the mesopic region. This is the range where we know the operation of our visual organ inadequately. Car headlamps ought to ensure good illumination also during mesopic conditions, but at the present, this is not satisfying at all.The last few years demonstrated that LEDs accomplish a revolution and could have many advantages in car headlamps. Their rigid construction is a major advantage, using different base materials and phosphors the light spectrum could be optimized for best vision on the road. But for this the visibility and glare functions of the human eye under mesopic conditions should be known precisely.We conducted experiments at the University of Pannonia, at the Virtual Environment and Lighting Laboratory to examine connection between better visibility and the possibilities of decreasing discomfort glare. We performed experiments with narrow band emissions in the following form: three LEDs have been selected, a red, a green and a yellow emitting. The red and green emitting chips were in the same housing, so their light could be mixed easily, producing the same colour as that of the yellow LED. During the experiment, observers had to set the red-green (RG) LED to the same disturbing glare level as they have seen it by the yellow (Y) LED.