Abstract: In an interactive display device and method, a video projector projects an image on a screen. An optical pointer includes a mouse click signal input button and a light source emitting a light beam for pointing to the screen to form a light mark. A detection camera acquires an image from the screen and detects an image from the light mark. A processing system calculates the position of the light mark in the detected image. The optical pointer includes: a contact or proximity detector capable of detecting a contact between one end of the optical pointer and the screen and generating a light mark presence signal; and moreover a radio transmitter capable of transmitting a light mark presence signal to a processing system. The treatment system compared the respective signals for detecting a light mark and light mark presence to deduce therefrom a validation signal for the light mark.