Optical system, image display apparatus, and image taking apparatus

An optical system comprising:

• a transparent body having a first optical surface, a second optical surface and a third optical surface,
• wherein a light beam made incident on said transparent body follows an optical path in which a light beam is transmitted through said third surface, is reflected on said first surface, reflected on said second surface, reflected on said first surface, reflected on said second surface, reflected on said first surface, reflected on said third surface and transmitted through said first surface in order or an optical path of the opposite order to exit from said transparent body.

An optical system comprising:

• a transparent body having a first optical surface, a second optical surface and a third optical surface,
• wherein a light beam made incident on said transparent body follows an optical path in which a light beam is transmitted through said third surface, is reflected on said first surface, reflected on said second surface, reflected on said first surface, reflected on said third surface, and transmitted through said first surface in order or an optical path of the opposite order to exit said transparent body.

An optical system comprising:

• a plurality of reflection surfaces that are eccentric with each other,
• wherein said plurality of reflection surfaces include a return surface that reflects the incident principal ray at central angle of view made incident such that the principal ray at central angle of view follows an optical path, which the principal ray at central angle of view followed, again reversely.