  In recent years, thermal display has been studied intensively in order to
represent a more realistic tactile quality of the object. Since human feels the
temperature of the air without touching other objects, it is necessary to
present thermal sensation in a non-contact manner. Studies on non-contact heat
display have been explored; however, few studies have reported on a device that
can display cold in a non-contact manner. In this study, we propose a
non-contact cold thermal display using a low-temperature heat source-vortex
tube, which can generate ultra-low air temperature when supplied with
compressed air. We developed a cooling model that relates the flow velocity of
cold air with the absorbed heat from skin; we implemented a prototype system
that can control the flow velocity of the generated air; and we conducted an
experiment to examine the cold sensation that the system can present. Our
results revealed that various cold sensations can be generated so that the
faster the flow velocity, the colder a user would feel.
