The transmission of olfactory information together with audiovisual information is now attracting much attention. However, the information is difficult to synchronize because of problems of scent lingering in the air and olfactory adaptation. We aimed at minimizing the amount of odorant presented to users in order to mitigate these problems, and developed an olfactory display that is able to present scents precisely. The display uses pulse ejection, whereby scents are emitted for only short periods of time. In this study, we aimed to mitigate the above-mentioned problems and to measure the time characteristics of olfaction in a single breath, which are difficult to measure by conventional methods. As a result, the most effective conditions for using a small amount of odorant in a single breath were revealed. These results are expected to ease the synchronization of olfactory and audiovisual information.

Trials on transmitting olfactory information together with audio/visual information are currently being conducted in the field of multimedia. However, continuous emission of scents creates problems of olfactory adaptations and scents lingering in the air. To overcome these problems, we developed an ink-jet olfactory display. This display has high emission control so that it can provide stable pulse emission of scents. Humans detect the scents when they breathe in and inhale scents molecules in the air. Therefore, it is important to synchronize the pulse ejection of scent presentation with the inspiration. With that, by using the pulse ejection of scents, we constructed the pulse ejection pattern what enables instantaneous switch of scents. We first measured the responding time to sense the shift of scents in order to achieve the pulse ejection pattern suited for switching the scents. Then, by using the pattern found in first experiment, we measured the shortest period of scent switching. At last, we measured the limit of switching scents. As a result, we constructed the presenting pattern of scent switching and the limit of scent switching when the scent switching was presented with its shortest period. It is expected that using this developed pattern with movies would raise the realistic sensations.