Investigation of legibility and visual fatigue for simulated flexible electronic paper under various surface treatments and ambient illumination conditions

This study employs simulated electronic paper to investigate critical issues and focuses on improving legibility of display and reducing users' visual fatigue. Three critical factors - choice of surface treatment, ambient illumination, and bending curvature - are evaluated through the method of a letter-search task. The results show that subjects performed better on legibility and felt less visual fatigue with an anti-glare treatment. Choosing the better anti-glare treatment instead of the anti-reflection series can save significant cost for manufacturers. In addition, ambient lighting of 1500 lux is more appropriate for reading on electronic paper than an environment with extreme illumination (e.g., 8000 lux). The present study also found that curvature had no impact on legibility or visual fatigue. These evaluations of simulated electronic paper may provide manufacturers useful information in fulfilling ergonomic requirements for product design.