We propose utilizing the ceiling of personal and office
spaces as an additional interactive display for both
single-user applications and collaboration. Ceilings offer a
display space that is unobtrusive, allows unobstructed
viewing from many positions, and allows direct mapping
to the room below. Previous research on ceilings as
interactive displays has focused on providing ambient
information. We argue that interactive ceilings are even
better suited for supporting collaboration between persons
in a shared room, and as an unobtrusive extension of a
user’s desktop. Also, interactive ceilings can display status
information directly above persons or objects on the floor.
We discuss perceptual and ergonomic properties of
interactive ceilings, propose concrete applications that
benefit from interactive ceilings, describe a rear-projected
prototype that we built with a size of 1.82 x 1.02 m, and
present the design of a study investigating perceptual
limitations of interactive ceilings.