A Pinch-based Text Entry Method for Head-mounted Displays

Pinch gestures have been used for text entry in Head-mounted dis-plays (HMDs), enabling a comfortable and eyes-free text entry. However, the number of pinch gestures is limited, making it difficult to input all characters. In addition, the common pinch-based meth-ods with a QWERTY keyboard require accurate control of the hand position and angle, which could be affected by natural tremors and the Heisenberg effect. So, we propose a new text entry method for HMDs, which combines hand positions and pinch gestures with a condensed key-based keyboard, enabling one-handed text entry for HMDs. With this method, users move their hands with a naturally comfortable posture between three large different spaces in the air to choose one key set and then execute one of the pinch gestures to choose one character, where hand jitter does not affect the selection, helping to improve the input speed. The results of a primary study show that the mean input speed of the proposed method is 7.60 words-per-minute (WPM).