The Everywhere Displays Projector: A Device to Create Ubiquitous Graphical Interfaces

This paper introduces the Everywhere Displays proj ector, a device that uses a rotating mirror to steer the light from an LCD/DLP projector onto different surfaces of an environment. Issues of bri ghtness, oblique projection distortion, focus, obstruction, and display resolut ion are examined. Solutions to some of these problems are described, together with a plan to use a video camera to allow device-free interaction with the pr ojected images. The ED-projector is a practical way to create ubiquitous g raphical interfaces to access computational power and networked data. In particul ar, it is envisioned as an alternative to the carrying of laptops and to the i nstallation of displays in furniture, objects, and walls. In addition, the use of ED-projectors to augment reality without the use of goggles is examined and illustrated with examples. 11Introduction Ubiquitous computing envisions a world where it is possible to have access to computer resources anywhere and anytime to the data and services available through the Internet [1]. Since most of current software and Internet data is designed to b e accessed through a high-resolution graphical interf ace, to truly ubiquitously compute todayusers need devices with reasonable graphical capabi lities. This means carrying laptops everywhere, wearing computer graphics goggl es, or installing monitors and displays on the surfaces of spaces and objects, suc h as desks, fridges, and entrance doors. Or, simply, toresign to the low-resolution displays of mobile pho nes or PDAs. In this paper we explore an alternative approach to create ubiquitous graphical interfaces. Our idea is to couple an LCD/DLP projec tor to a motorized rotating mirror and to a computer graphics system that can correct the distortion caused by oblique projection. As the mirror moves, different surfaces become available to be used as displays. Also, we plan to employ a video camera to detect hand interaction with the projected image using computer vision techniques. Our target is to develop a projection-based system that creates interactive displays everywhere in an environment by transforming a surf ace into a projected " touch screen. " Such an Everywhere Displays projector can be installed, for example, on the ceiling of a space, to provide a generic computer i nterface to users in that environment (see Fig. 1).