On the visual recognition of moving letter.

The visual recognition (i.e., legibility) of moving object was studied. The numerical letters were mainly used as the objects. The influences of (1) direction of the movement, (2) thickness of line of letter (i.e., stroke width), and (3) design of letter to the visual recognition were measured. From these measurements, the optimal numerical letters were proposed in the first step of the study, which were called as IMAL(initial most optimal arabic letters). The visual recognition of both moving letters IMAL and letters JIS (Japan industrial standard) employed for motionless-state was compared for both the moving and the motionless states. In the presentation for motionless state, letters JIS showed lower error rate, but the statistical significance was not proved, while in the presentation for horizontally moving state letters IMAL showed better visual recognition than letters JIS was the significant level of 5%. Therefore, the useful numerical letters for moving state could be designed in the study. Moreover, the visual recognition of letters IMAL was evaluated for various moving velocities. The optimal moving velocities for both letters IMAL and JIS were found.