A Pinch Operated Input Interface of Japanese Syllabary Table for an Optical See-through HMD

This paper proposes an input interface of Japanese for an optical see-through HMD in mixed reality environment, which enables a user input Japanese easily with hands-free and view the real/virtual world relatively widely and clearly the world a little shielded by a small output screen caused by the input. The proposed system adopts pinch gesture, which is popular to HMD users, and the Japanese syllabary table, which is always studied by Japanese learner. The system is implemented on Microsoft Hololens2 and introduces the hand-tracking technology in Microsoft Hololens2 to the recognition of the pinch gesture. Selecting one of 50 Kana from the Japanese syllabary table of the 10-line and 5 column Japanese fundamental character set, a user selects one of the 10 lines with his/her dominant hand, and one of the 5 columns with his/her other hand. A user test is conducted by 10 Japanese adults in comparison with the system keyboard input on Hololens2. The evaluation shows that the system achieves some important functions such as hands-free, low screen occupancy, and scalability to other language, while the precision of the recognition of the input is to be improved.