Effects of pixel density, character format, and character size on subjective readability of liquid crystal displays

摘要

We investigate the effects of pixel density, character format, and character size on subjective readability of liquid crystal displays (LCDs) for personal digital assistants. At 30 cm viewing distance, fifty subjects assessed the readability of 33 different display conditions which were displayed on photographic films that simulated LCDs. The results indicate that the character format for Japanese characters should be more than 10×10 pixels as the size of characters was smaller than 2.7 mm. For the characters of 2.7 to 3.5 mm, the preferred character format was 15×15 or 17×17. The preferred character format depends on pixel density, character size and stroke width. The preferred stroke width for Japanese characters was 200 to 300 μ. The relationships between character size and pixel density to obtain the satisfactory readability were discussed. From readability point of view, the pixel density of displays will be improved up to 250 or 300 pixel-per-inch.