Patent ID: 7499027

Claim:
A method for providing an input to an interactive display system, wherein the interactive display system includes an interactive display surface and is able to display images and detect objects that are proximate to the interactive display surface, comprising steps for: enabling a user to provide an input by directing light from a light source onto the interactive display surface to illuminate a portion thereof with the light from the light source; and detecting the light illuminating the portion of the interactive display surface with a light sensor that is also used for detecting light reflected from objects that are proximate to the interactive display surface, the light sensor producing a signal that is input to the interactive display system; determining a disposition and orientation of the light source based on characteristics of the signal that is produced by the light sensor, in response to a pattern with which the portion of the interactive display surface is illuminated by the light source, and wherein determining the disposition and the orientation of the light source comprises a step for determining a shape and an orientation of the pattern on the interactive display surface, and wherein the pattern is circular in shape when the light source directs the light onto the portion of the interactive display surface along a path that is normal to the interactive display surface, and the pattern is elliptical in shape when the light source directs the light onto the portion of the interactive display surface along a path that is not normal to the interactive display surface.