Recently, olfactory interfaces, in addition to visual, auditory, and haptic interfaces, have been examined to enhance the sensation of presence for virtual reality. We have proposed the concept of "projection-based olfactory display" and have developed several prototype systems to realize this concept. A projection-based olfactory display applies the principle of vortex rings launched from an air cannon to deliver a small amount of scented air through free space from a nearby location to the user's nose. The characteristics of projection-based olfactory displays offer strong potential in combination with traditional TV sets and desktop PC environments at home. In our latest prototype system, we implemented cartridge-type units to store the scent source and generate scented air of specific content. This approach allows users to freely choose among scent contents by simply replacing the cartridge. We also developed an interactive application that integrates our olfactory display with game-like, interactive audio-visual content.

No abstract

SUMMARYIf a person's eyes are more strongly attracted to target objects by matching a smell to an important scene of a movie or a commercial image, the value of the image content will rise. In this paper, we attempt to describe an image system that can also present smells, and the reason for the improvement, as indicated by gaze point analysis, in the presence of smell that is matched to an image. The relationship between the eye-catching ability and the position of the object of viewing was examined using images with a scene in which someone eats three kinds of fruits. These objects were gazed at for a long time on release of their scents. When the smell was not released, the gaze moved actively in an attempt to receive a lot of information from the entire screen. On the other hand, when the smell was inserted, the subjects became interested in the object and there was a tendency for their gaze to stay within the narrow area surrounding the image. We also investigated the effect on the memory of attaching smells to the flowers in a virtual flower shop by using an immersive virtual reality system (HoloStage TM ). Memorization was easier than with the scentless case. It appears that viewers obtain information actively by reacting to smell.

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 than capturing 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, but they 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 to the user's nose. To implement this concept, we used an "air cannon" that generates toroidal vortices of the scented air. We conducted a preliminary experiment to examine the possibility 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.

We have prototyped a KANSEI multimedia display (KMMD) that is able to release scent through the screen in order to realize collaboration between images and scents. Two types of “sukiyaki” food videos were presented to subjects using this device, and a method for objectively evaluating the realistic sensation of the food videos was examined using biological reaction measurements. The sukiyaki scent was added to one type of video to improve appetite. Viewers’ saliva flow rate, line of sight, pupil diameter, autonomic nerve activity, and cerebral blood flow were measured at the same time, and changes in these measured values were analyzed. As a result, the scent was effective in improving the sensation, as if the food was present in front of the eyes and increasing the saliva flow rate. Additionally, in a realistic scene, it was found that the line of sight follows the performer’s eating behavior as if the viewers themselves are eating. The sympathetic nervous system temporarily increases, mydriasis occurs, and the frontal lobe is activated. Furthermore, the possibility of objective evaluation of realistic sensations was demonstrated by the correlation between appetite, accompanied by salivary sensation, and the biological reaction measurement results.