为了满足汽车倒车需求，设计了一款结构简单、生产成本低廉的广角倒车镜头。镜头为4 片式结构，第1 片为玻璃，其余3 片为塑料，使镜头满足在恶劣环境下工作的要求。镜头F 数为2.8，水平视场为185°，且实验结果显示边缘视场畸变得到较好控制。设计的镜头已经开始量产。

In order to meet the needs of the backing-up lens in cars, a wide-angle lens has been designed. The lens has four elements, the first is a piece of optical glass, the other 3 elements are plastic, and the lens is able to work under bad conditions. The lens has an F number of 2.8, the horizontal field is 185 degrees, and the test showes that the off-axial distortion is corrected perfectly. Mass production of the lens has begun.