Design of high resolution panoramic annular lens system

Abstract

Panoramic annular lens (PAL) system consists of a panoramic head block unit and a relay lens system, adopting a plane cylindrical projection method to project a cylindrical field of view around the optical axis 360° into a two-dimensional planar annular region to realize super hemispherical imaging. PAL system requires large field of view imaging on a limited image plane, which inevitably results in lower image resolution and poor local detail imaging. However, the information processing speed gets faster with the development of 5G, which leads to a growing demand for better image quality and clarity. This paper presents a PAL system matching image sensors with 4K resolution, which can demonstrate the details about the object and get a smooth and ultra-high definition image. Unlike other sensors, it has large image faces and tiny pixels and the effective number of the pixel is about 24.3 million (4K × 6K). The proposed PAL system has 6 sets of 9 lenses with compact structure. The F-theta distortion of the full field of view is less than 1%, and the modulation transfer function value of each field of view is greater than 0.5 at the Nyquist spatial frequency of 130lp/mm which approaches diffraction limitation. The designed system has good imaging quality and meets the application requirements.