Abstract
Irradiation is a phenomenon that causes white objects on a black background to appear to spread into near dark backgrounds, but the reverse is not. In this study, the effects of font size and thickness of letters on the legibility were investigated in combinations of black letters/white background as well as white letters/black background. Ten subjects who had been no disease of eyes and their eyesight is over 1.0 were recruited and tested subjective assessments of letter sizes for various font sizes (2pt to 80pt) and thickness of letters (normal, bold) under 600lux illumination and 50㎝-distance of eyes and target letters for this study. Ming-style font type which was generally used in text of books, papers, and joumals were tested in this study. Results showed that generally people subjectively assessed the white letters on black background (W/B) were larger sizes of letters than the black letters on white background (B/W) even both letter sizes were the same in both nomlal and bold thickness of letters. This phenomenon was happened in case of only over 22 font size (with border line about 22-24pts). Less than 22 font sizes, many people reported that both letters (W/B and B/W) are looks the same sizes in normal as well as bold letters. These findings were interpreted also by the in
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
