The general field of the invention is that of monochromatic stereoscopic image projectors including two light sources that illuminate two imagers, the radiation of the two light sources having a spectral distribution centred on a central wavelength, the first imager and the second imager being connected to a generator of stereoscopic image pairs. The image projector includes a dichroic separating filter that transmits the portion of the spectrum below the central wavelength and that reflects the portion of the spectrum above this central wavelength. The first light source and the second light source are arranged symmetrically on either side of the dichroic separating filter. The image projector operates cyclically, each cycle including two alternations. Each alternation consists in changing the emission source and in switching to the two displays the left and right images emitted by the generator of image pairs.