Character input by gesture performed with grasping both ends of tablet PC

Abstract

We developed a method to enter Hiragana (cursive in Japanese) characters and alphanumeric characters by thumb gestures for Japanese people. This method is optimized to be used while holding the left and right ends of a tablet PC with hands. Each gesture is designed by concatenating a few horizontal and/or vertical strokes, but path of the gesture remains inside the one-stroke square centering its starting position. A Hiragana character is input by selecting a row of the table of Japanese syllabary and then a column of the table. The alphabet characters are segmented into 6 groups in order of letters. Just like Hiragana, an alphabet character is entered by selecting a group and then selecting a member. However, in the alphanumeric mode, to reduce the cost of modifying the mistakenly selected group, an operation to move to the previous or next group have been added. Characters are entered by gestures executed by the dominant hand. Gestures carried out in the opposite hand are assigned to some control codes that are needed to kana-to-kanji conversion and document modification. Since the input guide on the display is rewritten each time when one stroke is recognized, a user can enter any character by moving the thumb to the direction of the character shown on the guide, even if he or she does not memorize its gesture. In the experiment entering Hiragana, input speed of beginners was about 20 [CPM]. A person skillful at this method could input about 58 [CPM] without watching fingertips.