Virtual image optical system

There is provided a virtual image optical system which removes the noise caused by stray light, removes the aberration, and which can be implemented in a smaller size. The virtual image optical system includes a reflective spatial light modulator, an illuminating light source device, eyepiece optics, and a light source optical system. The light source optical system includes at least one beam splitter. The eyepiece optics include at least one beam splitter and reflector. An angle formed by a plane normal vector formed with respect to the reflector of the eyepiece optics and a plane normal vector formed with respect to the beam splitter is in the range of 136 degrees to 179 degrees.