Rear projection optical system

A rear projection optical system for being installed at a rear side of a screen of a rear projection apparatus, the rear projection optical system comprising:

• a display panel;
• an illuminating optical system for illuminating the display panel, the illuminating optical system being decentered from a screen center in both a horizontal direction and a vertical direction;
• and
• a projection optical system, decentered from the screen center in the vertical direction, for projecting a display image on the display panel projected by the illuminating optical system onto the screen through a rear mirror positioned at a position that is the center of the screen,
• wherein the projection optical system includes a dioptric system, a deflection mirror, and a projection curved mirror in this order from the display panel to the rear mirror, and wherein the projection curved mirror is decentered from the screen center in the vertical direction but centered against the screen center in the horizontal direction, and
• wherein, when the rear projection apparatus is observed from one side thereof in the vertical direction, the illuminating optical system at least partly overlaps with a light flux from the rear mirror to the screen.