Abstract: In order to visualize an active matrix liquid crystal image generator, it is illuminated in a prism system by a light source and a collimator directing light into the prism system and made linear polarized and reflected by a first half-mirror layer between two joined prism surfaces, the image generator differentially twisting pixelwise the polarization plane of reflected light therefrom, such that twisted light can traverse the first half-mirror layer and a second half-mirror layer for focusing by a concave mirrors, the second half-mirror then directing a virtual image toward an eye location, from which a natural scene may also be viewed. The prism system, as seen in a plan perpendicular to the viewing direction, includes two isosceles prisms and one of trapezium section, or preferably that of a parallelogram.