Single projector multiview displays: directional illumination compared to beam steering

We present two multiview rear projection concepts that use only one projector with a digital micromirror device light modulator. The first concept is based on time sequentially illuminating the light modulator from different directions. Each illumination direction reflects on the light modulator toward a different viewing zone. We designed an illumination system that generates all distinct illumination beams and a lens system integrated into the projection screen to enlarge the viewing angles. The latter is crucial since the viewing extent of the viewing zones decreases inversely proportional to the size of the projected image. A second concept is based on a specific projection screen architecture that steers images into different horizontal directions. In this way, the entire acceptance etendue of the projection system can be used for every image. This is achieved by moving a double-sided lenticular sheet horizontally with respect to a sheet of microlenses with a square footprint. Both concepts are investigated with advanced optical simulations