RPTV: Rear Projection Television, in German rear projection television, is a display method in which the image generated by a projector is thrown onto the screen from behind. This technique is used, for example, in cinemas where there is not enough space for a projector room in front of the screen.
In television sets, the technology is basically similar to conventional tube televisions.
The picture is based on three cathode rays in the primary colors blue, green and red. The rays are bundled by a lens system and deflected by a mirror onto the projection surface. The technology is particularly suitable for large screen diagonals.