A Study of Ergonomic Requirements for Japanese Character Sizes and Matrixes on Computer Displays

摘要

The present study was carried out to find an optimum character size and character matrix on computer displays for Japanese characters. At first a field study was performed to assess the actual conditions under which computer users do their daily work. The field study revealed that smaller fonts than are ergonomically recommended were frequently used. Secondly, a human factors' experiment was carried out to find an optimum size. Three kinds of displays with different pixel densities were used, because we predicted that pixel size would affect the users' preferences for character appearance. The results showed that the preferred character height decreased as the pixel pitch of the display increased and the pixels became smaller. The preferred character matrix, however, was almost constant. This demonstrated that the character matrix was given a much higher priority than character height, because the matrix controls such factors as the optimum stroke width and the general appearance of a font. We suggest new ergonomic requirements for character height and matrix size for Japanese characters based on the field study and the experiment. The proposed character height that is the minimum for readability is 20 minutes of arc, and the preferred range is 25 to 35 minutes of arc. Regarding the character matrix, we recommended that 11 x 11 be the minimum, and more than 15 x 15 is preferable.