Patent attributes
The invention relates to an optical system which is adapted to form an image having a full 360° (panoramic)-direction angle of view on an image plane or project an image located on an image plane in a full 360° (panoramic)-direction angle of view, and which is of small-format size and high resolving power yet without being affected by flare light. The optical system comprises a front unit (10) having two reflecting surfaces and two transmitting surfaces, each rotationally symmetric about a center axis (1), a rear unit (20) that is rotationally symmetric about the center axis and has positive power, and an aperture (5) located coaxially with the center axis. A light beam incident onto the front unit passes through the first transmitting surface (11), and is reflected at the first reflecting surface (12) located in opposition to the first transmitting surface with the center axis between them in a direction away from the image plane and then is reflected at the second reflecting surface (13) located on the same side as the first transmitting surface in a direction toward the image plane, leaving the transparent medium via the second transmitting surface (14). The outgoing light is imaged on the image plane (30) by way of the rear unit (20) such the entrance pupil (6Y) in the section including the center axis (1) is positioned near the second reflecting surface (13).
