Olfaction stimulates our emotion most vividly among five senses, so it is effective to use scent as a medium for communication. In order to show hundreds of thousands kinds of scent one by one, as many as hundreds of thousands of scented substances are needed and it is impossible to be achieved. In this research, we use knowledge of cognitive psychology that olfaction is susceptible to other senses, especially vision. Practically, we suppose a new method presenting a scent and a picture not corresponding with the scent at the same time and having audience smell not what they actually smell but what they see. If we achieve the goal of giving an olfactory illusion, we will be able to represent various scents by few kinds of scented substances. As a result, this research will make a large impact on olfactory display systems which are underdeveloped yet.
