Mid-air displays enabling novel user interfaces

Displays are the most visible part of most computer applications. We discuss how displays have an impact on the possibilities of future computers and their user interfaces. The issue is especially interesting for the era of ubiquitous computing or ambient media, where fundamental changes will happen for the whole context of computing. Displays may be everywhere or nowhere, depending on the situation. We present some of our experiments with a novel category of displays, the "immaterial" FogScreen. It can be described as a novel media platform as it has some fundamental differences and advantages over other displays. It also enables novel kinds of user interfaces and experiences. In this paper we will look onto it as an enabling technology for future user interfaces.