The present invention provides a projection system (10), preferably for a head-up display e.g. on board a vehicle, comprising a laser source (1), a diffuser (3) and telecentric optics (2) disposed between the laser and the diffuser so that the telecentric optics outputs parallel rays to the diffuser, the diffused light being thus independent from the incidence angle; each pixel of the projected image has the same brightness, regardless of the angle or of the position from which it is viewed.