Nooree Na, a Ph.D. candidate of Color Lab published an article entitled, “Adaptive display luminance for viewing smartphones under low illuminance,” in Optical Express, which is ranked 1st out of 86 journals in optics category. The study developed a model of adaptive display in that display luminance changes gradually with the passage of watching time for viewing smartphones in conditions of low illuminance. The model was validated by several empirical studies including physiological comfort and psychological satisfaction.
The study investigates the optimal display luminance for viewing smartphones in conditions of low illuminance. This proposes a model of adaptive display in that display luminance changes gradually with the passage of watching time. It starts at a fairly low display luminance of 10cd/m², and after 10 seconds, the luminance increases slowly until it reaches 40 cd/m² for 20 seconds and maintains the luminance. For the development of the model, an experiment was conducted to identify the optimal luminance for initial viewing and that for continuous viewing, as well as the change speed of display luminance. In order to validate the model, users’ subjective judgments and activation of alpha rhythm were observed, and the result confirmed the superiority of the adaptive display luminance compared to the current display luminance in terms of physiological comfort and psychological satisfaction. It is expected that this study contributes to the pleasing use of displays at night under low illuminance by applying to diverse types of display devices.