Patent ID: 7289113

Claim:
An interactive display system, comprising: a) a touch-sensitive display screen for sensing pressure applied thereto and in response generating control signals indicating locations of said applied pressure, b) structure configured to receive said control signals and in response generate graphic images to be projected onto said touch sensitive display screen at said locations, c) a computer for executing one or more applications programs in a multi-tasking environment and in response generating screen video displays, said computer being connected to said touch-sensitive display screen, d) a driver in said computer for receiving said control signals and in response generating a command to a selected one of said applications programs for updating said screen video displays in accordance with said applied pressure to said touch-sensitive display screen, e) a projector connected to said one or more computers for receiving and projecting said screen video displays onto said display screen, and f) structure for modifying location data in said command to thereby align said screen video displays with the location of said pressure applied to said display screen, wherein said command includes data for identifying horizontal and vertical coordinates of the location of said pressure applied to said display screen, and wherein said structure for modifying comprises a software routine for generating via said projector a plurality of alignment images onto said display screen at predetermined locations, detecting user applied pressure on said display screen at the respective locations of said images, and in response calibrating said horizontal and vertical coordinates to compensate for keystoning caused by planar misalignment between said projector and said display screen.