The Effects of Ambient Illuminance on Display Brightness Perception and Readability

Brightness perception of human visual system (HVS) not only depends on physical luminance but also other factors, such as surrounding illuminance. In this study, to investigate the influence of ambient illuminance on perceived brightness and readability during display usage, a lab study with a within-subjects (N = 12) design was conducted. The subjects evaluated the brightness perception and readability of five display luminance conditions (10, 32, 100, 316, 1000 cd/m
²
) under five ambient illuminance conditions (1, 10, 100, 1000, 10000 lx). The results showed that perceived brightness value increased as the display luminance increased. And brightness perception intensity decreased as the ambient illuminance increased. This indicates that the decrease in ambient illumination can appropriately enhance the perceived brightness, which provide a new solution to improve display brightness perception instead of enhancing the maximum display luminance alone. As for the results of readability, it showed that the effect of ambient illuminance on display readability is influenced by display luminance. At low display brightness levels (10, 32 cd/m
²
), the recommended illumination range with high readability is 1-10lx. At medium and high display brightness levels (100, 316, 1000 cd/m
²
), the recommended illumination range with high readability is 10- 1000lx.