Projection optical apparatus

A projection optical apparatus, comprising:

• a reflection type display device,
• a projection optical system for projecting an image displayed on the reflection type display device onto a projection display screen, and
• an illumination light source for illuminating a display surface of the reflection type display device, wherein:
• the projection optical system comprises an optical element having positive power,
• said optical element being located in opposition to the display surface of the reflection type display device, and said optical element comprising at least two reflecting surfaces, at least one of which is defined by a rotationally asymmetric curved reflecting surface configured into a curved shape that imparts power to a light beam,
• the illumination light source is located such that given two light rays are reflected at at least a first reflecting surface of the reflecting surfaces of the optical element as counted in order of a projection light ray traced from a display surface side, provided that said given two light rays are a light ray leaving the display surface and arriving at the projection display screen and a light ray leaving the illumination light source and arriving at the display surface,
• said illumination light source being located such that an axis of illumination light incident on the optical element is not included in a given plane, wherein:
• said axis of illumination light is defined by a center light ray of an illumination light beam from the illumination light source, said center light ray arriving at a center of the display surface,
• an axis of projection light is defined by a light ray leaving the center of the display surface and arriving at the projection display screen through a center of a pupil of the optical system, and
• said given plane is a plane that passes through the axis of projection light leaving the optical element and the center of the display surface, and
• the reflection type display device comprises a two-dimensionally arrayed micro-mirrors, each having a variable gradient so that an angle of emergence of reflected light can be varied.