Patent ID: 8879157

Claim:
An observation optical system configured to introduce light fluxes from a plurality of display elements to an exit pupil via an optical element having a plurality of optical units, and to present a combined and enlarged image, each display element being configured to display an original image, wherein each of optical units of the observation optical system has a plurality of reflective surfaces, and a reflective surface that has the highest refractive power among the plurality of reflective surfaces has a symmetrical plane, and when a decentering section is defined as a section that contains the symmetrical plane, the plurality of optical units are arranged so that the decentering sections of the plurality of optical units are parallel to each other, the reflective surfaces each of which has the highest refractive power in two adjacent optical units intersecting each other so that each reflective surface having the highest refractive power projects from the reflective surface having the highest reflective power of a counterpart to a side of the exit pupil of the counterpart.