Tokyo-based
Toppan Printing, who works in collaboration with electronic paper display maker
E-Ink, has demonstrated a stunning 400ppi (pixels per inch) high resolution e-paper prototype. Toppan has also manufactured the highly acclaimed 170ppi display of Sony's e-book reader LIBRIé.
Speaking of display resolution: High resolution is as good as the human eye can resolve. Going beyond it would be pointless because the average human eye could not appreciate any finer detail. In a monochromatic image at a normal reading distance, the human eye is not able to perceive more than 250-300ppi. In other words, the 400ppi display prototype easily matches the resolving power of the eye making text as sharp as it can get!
Beside featuring a high resolution, in contrast to traditional display technologies on the market today, E-Ink's e-paper technology also makes text extremely easy to read at virtually any angle and under any lighting condition - including direct sunlight.