The way to stop video pirates using camcorders to copy films in cinemas, Kodak claims, is to switch to a digital projection system that harnesses a new trick the company has dreamed up.
Unlike a film projector, a digital projector directs red, green and blue light onto the screen separately, using computer-controlled mirrors. In US patent 2004/0150794, Kodak proposes introducing a flicker of around 100 hertz into these beams, using a slightly different frequency for each colour. Though the flicker is too rapid to be detectable by the human eye, it interferes with the camcorder’s electronics to make the red,…
