A design of panoramic lens system to realize the projection from the local annular object field to rectangular image field by using freeform surfaces

摘要

Nowadays, panoramic annular lens (PAL) applies in aerospace, robotics vision, industrial pipeline endoscope and corporate video conferencing. A cylinder-to-plane projection which called the Flat Cylinder Perspective (FCP) is adopted in PAL. The FCP projected the three-dimensional cylindrical field object onto a two-dimensional annular image plane. The optical system has fade zone in the center of detector. Based on the structure of the PAL system, this paper shows that a panoramic lens is designed with free-form surfaces. In the designed optical system, the local annular object field of view is projected onto a rectangular image plane. The free-form panoramic lens has a wide field of view of 140°in horizontal direction and a field of view of 40°in vertical direction. The design of the panoramic lens can maximize the use of area and have no fade zone in rectangular detector.