Psychophysical research on switching between light emitting and reflecting modes of light adaptable display considering equal visibility

Viewing high-luminance displays such as liquid crystal displays or organic light emitting diode displays under low-light conditions causes an unbearable glare, while viewing them with low luminance under bright-light conditions reduces visibility. Recently, several research groups have reported light adaptable displays (LADs) to extend display visibility over a wide range of light conditions. Here, we present a psychophysical study on how to effectively utilize the LAD using two different display types for the first time. LAD features two switchable display types: light emitting mode (LEM) and light reflecting mode (LRM). To maintain visibility and prevent visual artifacts, we investigate when to switch modes between LEM and LRM. We conduct psychophysical experiments involving seventy subjects. They are asked to select illuminance levels under which they perceive that the LEM and LRM look the same depending on luminance of the LEM. We propose a mode-switching condition by combining our previous results on the comfortable luminance of LEM display according to the ambient illuminance and the selected illuminance results providing equal visibility of both LEM and LRM displays.