CHI 2003: NEW HORIZONSPosters: Computers Everywhere

An Unencumbering, Localized Olfactory Display
Yasuyuki Yanagida, Haruo Noma, Nobuji Tetsutani
ATR Media Information Science Laboratories
2-2-2 Hikari-dai, “Keihanna Science City”
Kyoto 619-0288 Japan+81 774 95 1401
{yanagida, noma, tetsutani}@atr.co.jp

Akira Tomono
Dept. of Information Media Technology
Tokai University
1117 Kitakaname, Hiratsuka
Kanagawa 259-1292 Japan+81 463 58 1211
tomono@keyaki.cc.u-tokai.ac.jp

By localizing the scent, we can display different smells tomultiple users. Also, we can significantly reduce theamount of (often expensive) odorant compared with justdiffusing the scent into an entire room, as the volume of theair with odorant is so small. The system can thus be relatively cost-effective. In addition, this small clump ofscented air can easily dissipate in a short time, which enables us to wield short-term control of the olfactory effect.

ABSTRACT

Olfaction is considered to be an important sensory modality
in next-generation virtual reality (VR) systems. We currently focus on spatiotemporal control of odor, rather thancapturing and synthesizing odor itself. If we simply diffused
the odor into the atmosphere, it would be difficult to clean
it away in a short time. Several olfactory displays that inject
the scented air under the nose through tubes have been proposed to realize spatiotemporal control of olfaction, butthey require the user to wear something on one’s face. Here,
we propose an unencumbering olfactory display, by conveying a clump of scented air from a certain remote place tothe user’s nose. To implement this concept, we used an “aircannon” that generates toroidal vortices of the scented air.
We conducted a preliminary experiment to examine thepossibility of this method’s ability to display scent to a restricted space. The result shows that we could successfully
display incense to the target user.

SYSTEM DESIGN

The entire system is composed of a head/face tracker, scentgenerator, and an air clump launcher, and a scent generator,
as shown in Figure 1. First, we have to detect the positionof the user’s nose. For this purpose, we can apply existingvision-based face tracking techniques.
Next, how to transfer the clump of scented air from a remote place to the nose through free space is the key to realize the system. Now let us focus on an important part of thesystem, the “air clump launcher”. We propose to use an “aircannon” for this purpose. An air cannon (also known as avortex cannon) is a chamber with a round aperture, and it isvery popular in science demonstrations for children. The
simplest way to make an air cannon is to use a cardboard
box, cutting out a hole and sealing the seams with packingtape. If we fill the box with smoke and push it gently, asmoke ring is observed to move smoothly at the speed ofapproximately 1 meter per second. This ring demonstrates aKeywords

Olfactory display, virtual reality, air cannon
INTRODUCTION

VR systems have been developed to cover visual, auditory,
and haptic sensations, so it is a natural progression to apply
olfaction. Although olfactory displays for VR are still at a
beginning stage, researchers have already started to explore
the possibility of olfactory displays [1, 2].
Hirose et al. [3] have developed several head-mounted typeolfactory displays. In these display systems, scented air wassent to the nose through a tube. However, it could be much
more useful if users do not need to block their faces withany devices, or to trail cumbersome tubes.

Head tracking

The technical challenge in our research is to restrict thescent emersion to a specified local space, while the scented
air is launched from some remote position: scent can beperceived only in a limited range of space at a certain time.

Transferring
scented air

Detecting nose positionCopyright is held by the author/owner(s).
CHI 2003, April 5–10, 2003, Ft. Lauderdale, Florida, USA.
ACM 1-58113-637-4/03/0004.

Air cannon

Aiming atthe nose

Figure 1: Concept of unencumbering, localized
olfactory display.

988

CHI 2003: NEW HORIZONSPosters: Computers Everywhere

Figure 2: A smoke ring launched from the air cannon.
toroidal vortex generated by the air cannon, and it showsthat the vortex can carry particles that exist around the aperture when the air cannon launches the air. The schematic ofa toroidal vortex is shown in Figure 2. It is not necessary
for the scent generator to fill the chamber with scented air:it only has to spray the scent just before the air cannon
launches a clump of air. Thus we can send a different scentwith each launch and cover multiple users with a single aircannon.

Figure 3: A prototype system.
sults showed that the proposed method has the potential tostably display scent to a particular user.
CONCLUSIONSThe platform on which the air cannon is mounted will becontrolled to aim at the user’s nose (to be done). Two degrees-of-freedom angles (azimuth and elevation) are controlled to determine the direction of the air cannon. A partof the prototype system is shown in Figure 3.
PRELIMINARY EXPERIMENT

We proposed a novel configuration of an olfactory displaythat does not require users to put anything on the face andthat localizes the effective space of the displayed scent. The
technical key to realize this concept is to transfer a clump ofscented air from a remote place to the nose, and we confirmed that this is possible by using an air cannon.

We conducted an experiment to examine how stably an aircannon can provide scent to the user from a remote place,and if it is possible to display scent separately to different
users. We filled the air cannon with the smoke of a SENKO(Japanese incense stick) to observe the aspect of launchedvortices, as well as to use it as a kind of odorant.

Future works include precise theoretical analysis of a toroidal vortex for the optimal design of air cannons, the design of the scent generator/switcher to be mounted on theair cannon, and so on. We are going to solve these problems step-by-step to construct a transparent, easy-to-use
olfactory display system.

Two subjects were asked to sit on chairs side-by-side, andthe air cannon was placed on a tripod 120 cm from the subjects. The distance between the noses of the two subjects
was 50 cm. Subjects were asked to close their eyes during
the experiment and to raise their hands if they could detect
the smell. The air cannon was set to aim at the two subjects
and at other places in random order each time it launched asmoke ring.

ACKNOWLEDGMENTS

This research was conducted as part of “Research on interaction media for the high-speed & intelligent networking”,
with funding from the Telecommunications Advancement
Organization of Japan.
REFERENCES

1. Barfield, W. and Danas, E. Comments on the Use ofOlfactory Displays for Virtual Environments. Presence,Vol. 5, No. 1, pp. 109–121, 1996.

There were 59 trials in total; including 11 miss hits (smokerings were not stable enough to reach the subjects). Amongthe successful hits, in 9 trials the air cannon aimed at nonsubject targets; therefore, the number of hits to either of thesubjects was 39. The successful smell detection rate was
72% for total (28 out of 39). There was no trial in which
either subject reported the smell when the smoke hit a different target, including the point between the two subjects.
Among the successful hits to the face, the smoke reached
the forehead in 8 trials, and of these the subject reported thesmell only 1 time. If we exclude these cases, the successful
detection ratio raises up to 87% (27 out of 31). These re-2. Davide, F., Holmberg, M., and Lundström, I. Virtual
olfactory interfaces: electronic noses and olfactory displays. Communications through Virtual Technology:
Identity, Community and Technology in the Internet Age(G. Riva and F. Davide ed.), Chapter 12, pp. 193–219,
IOS Press, Amsterdam, 2001.
3. Hirose, M., Tanikawa, T., Tanaka, S., and Sakikawa, S.
A Study of Olfactory Display. Proc. of the Virtual Reality Society of Japan 5th Annual Conference, pp. 193–196, 2000 (in Japanese).

989