Projection based olfactory display with nose tracking

Most attempts to realize an olfactory display have involved capturing and synthesizing the odor, processes that still pose many challenging problems. These difficulties are mainly due to the mechanism of human olfaction, in which a set of so-called "primary odors" has not been found. Instead, we focus on spatio-temporal control of odor rather than synthesizing odor itself. Many existing interactive olfactory displays simply diffuse the scent into the air, which does not provide the ability of spatio-temporal control of olfaction. Recently, however, several researchers have developed olfactory displays that inject scented air under the nose through tubes. On the analogy of visual displays, these systems correspond to head-mounted displays (HMD). These yield a solid way to achieve spatio-temporal control of olfactory space, but they require the user to wear something on his or her face. Here, we propose an unencumbering olfactory display that does not require the user to attach anything on the face. It works by projecting a clump of scented air from a location near the user's nose through free space. We also aim to display a scent to the restricted space around a specific user's nose, rather than scattering scented air by simply diffusing it into the atmosphere. To implement this concept, we used an "air cannon" that generates toroidal vortices of the scented air. We conducted a preliminary experiment to examine this method's ability to display scent to a restricted space. The results show that we could successfully display incense to the target user. Next, we constructed prototype systems. We could successfully bring the scented air to a specific user by tracking the nose position of the user and controlling the orientation of the air cannon to the user's nose.