Localized scent presentation to a walking person by using scent projectors

We have developed a system to provide scents locally, both in space and time, to people who are walking down an aisle. The system is based on a scent delivery technique that uses scent projectors that launch vortex rings containing scented air. The walking trajectory of a person who approaches the system is detected by a time-of-flight-based range imaging camera, and the system generates a small volume of scented air just in front of the target person by causing two vortex rings to collide with each other.