Projection display system

摘要

A projection display system comprises a presentation computer (1) which generates images which are projected onto a screen (4) using a projector (3) controlled over a line (2) by the computer (1). A video camera (5) views the screen and a laser pointer (8) is supplied for pointing at the screen (4). An interaction computer (7) analyses the signal produced by the video camera (5) to determine the position of peak value in a frame to locate the point at which the laser pointer (5) is pointed. The laser pointer (6) is provided with buttons (10) which perform conventional computer mouse button functions. The state of the buttons (10) may be signalled to the computer (7) over an infra red link (9).