Zhang Kun, Zhong Xing, Zhang Lei, Zhang Tianqing
Appl Opt. 2020 Jul 1;59(19):5737-5744. doi: 10.1364/AO.395598.
A panoramic annular lens (PAL) comprises a panoramic annular head unit (PAHU) and a relay lens group. Due to the properties of annular imaging, single-channel PAL systems contain a blind area in the central field of view (FOV), which is difficult to reduce in a traditional optical system structure. Therefore, we propose a novel reflective PAHU structure, using two mirrors to replace the traditional single-lens- or multilens-cemented PAHU, to achieve a smaller blind area and ultrawide-angle imaging. In this paper, we present the design of an ultrawide-angle PAL with a FOV of (22∼120)×360 using our proposed method. The resulting optical system achieves a blind area ratio of less than 3.67%. Compared with the traditional PAL system with the lowest blind area ratio, the blind area ratio of our system is reduced by half, demonstrating the feasibility of the proposed method.
全景环形透镜（PAL）由全景环形头部单元（PAHU）和中继透镜组组成。由于环形成像的特性，单通道PAL系统在中心视场（FOV）中存在一个盲区，在传统光学系统结构中难以减小该盲区。因此，我们提出了一种新颖的反射式PAHU结构，使用两个反射镜取代传统的单透镜或多透镜胶合PAHU，以实现更小的盲区和超广角成像。在本文中，我们使用所提出的方法展示了一种视场为(22∼120)×360的超广角PAL的设计。所得光学系统的盲区比小于3.67%。与具有最低盲区比的传统PAL系统相比，我们系统的盲区比降低了一半，证明了所提出方法的可行性。
