Minimum ambient illumination requirement for legible electronic-paper display

The intent of this study is to determine the minimum ambient illumination requirement for legible electronic-paper display. Not only the young but also the elderly were included as research subjects. Through the method of character-search task, the results indicated that the significant performance improvement of all subjects occurred at 52 lux on the search time and at 62 lux on the subjective visual fatigue. Therefore, the minimum ambient illumination requirement for legible electronic-paper display can be synthesized at 62 lux. This minimum point of ambient illumination for the young and the elderly represents that the reflective-type display started presenting its better legibility and the subjective visual fatigue started decreasing. As electronic-paper display technology applications gradually expand, product designers need notice this fundamental limit of electronic-paper display when they continue to create possible applications in the future.

Research highlights
► The minimum illumination requirement for legible e-paper display was determined.
► Not only the young but also the elderly were included as research subjects.
► The significant performance improvement occurred at 52 lux on the search time.
► The significant improvement occurred at 62 lux on the subjective visual fatigue.
► The minimum key point for legible e-paper display can be synthesized at 62 lux.