The invention discloses a projection optical system for projecting an original
image onto a projection surface. The projection optical system comprises a plurality
of aspherical curved mirrors, which reflects image light from the original image
in sequence and then forms an image on the projection surface. The projection optical
system forms a projected image on the projection surface at an aspect ratio different
from that of the original image by a combination of reflective actions of the image
light on the aspherical surfaces of the plurality of aspherical curved mirrors.
Even in a projection optical system having a wide angle of view and a short distance
of projection, it is possible to implement a projection optical system that is
capable of suppressing distortion and performing an optical aspect conversion.
