Abstract
Touch panels have applications in a wide range of situations. For example, they are used in ticket-vending machines at stations, automated teller machines at banks, and in the medical field. Owing to this widespread use, much research regarding touch panel operability has been done. Accordingly, the interface design of touch panels has improved. However, there has been no research focusing on how covering the display with hand can affect touch panel operability. In this study, we conducted one experiment to evaluate the effect on touch panel operability when the hand covers part of the display. In addition, we measured maximum torque ratio of the upper arm to evaluate arm load during touch panel operation. In this experiment, ten healthy male subjects were asked to operate touch panels under three touch-panel angle conditions: 0, 45 and 90 degrees. We also measured the area on the display covered by the hand, switch pointing time, the subjects' complaint of visibility of the display and maximum torque ratio of each joint as evaluation indexes. The results showed that touch-panel angle has an influence on the range and position of the area that the hand covered. Additionally, switch pointing time and the subjects' complaint of visibility both became worse when the display was covered with the hand. Moreover, we found that the value of the maximum torque ratio of the upper arm decreased when the touch-panel angle was 90 degrees.
