||The present invention relates to projection systems for displaying visual information. These projection systems can be used in the fields of television, computer techniques, medicine, cinema, transports as well as in other applications. According to its different embodiments, the purpose of the present invention is to provide a surface projection for reducing the projection area, and thus the weight and the dimensions of the projection systems, and/or for observing glare-free images while maintaining a bright external background on the screen. In one embodiment as shown in fig. 1, the projection system for producing an external surface projection on a visualisation screen comprises a flat and thin visualisation screen for a carrying out a projection on both sides. Images can thus be watched on the left side (1a) and on the right side (1b) of this screen. From the surface of the screen and on the left (1a) and right (1b) sides thereof, projectors (2a, 2b) are provided for projecting images simultaneously on both sides of the screen. Light diffusers (3a, 3b) are also provided on both sides of the screen for capturing, diverting and diffusing the projection beams respectively on the left or right sides relative to the image observation direction. The projections are converted through the optics of the projectors (2a, 2b) so as to form reduced-divergence projection beams ( alpha 1, alpha 2) which are entirely captured by the light diffusers and which are diverted and diffused at wide angles ( beta 1 or beta 2) of image observation ranges. The surface of the screen (1) may include a mat antiglare blackening or the screen may have an adjustable transparency.