基于电晕检测过程中要求紫外光学系统大视场搜索、小视场探测的需求，针对工作波长范围为0.24~0.28 μm 的日盲区紫外波段，设计了“日盲”紫外机械补偿变焦光学系统。根据用户要求，其焦距为30~60 mm，F 数为3.5，选用PIXIS型1024BUV 1 inch(1 inch=2.54 cm)紫外CCD，像元尺寸为13 μm ×13 μm ，对应视场为8°~16°。系统由8 片透镜组成，引入两个非球面，使系统具有结构简单、成本低等优点。像质评价表明，在截止频率38 lp/mm 处,各视场的光学调制传递函数均在0.7 以上，接近衍射极限，畸变小于3%，在整个变焦范围内像质优良，满足用户总体设计的要求。

According to the requirements of corona detection on searching targets with large field of view and detecting objects with small field of view, a refractive zoom optical system using mechanical compensation technology and working at“solar blind”ultraviolet wavelength (0.24~0.28 μm ) is designed. According to the requirements of users, the focal length spreads from 30 mm to 60 mm, and F number is 3.5. PIXIS 1024BUV CCD with size of 1 inch (1 inch=2.54 cm) and pixel size of 13 μm ×13 μm is used as a sensor. The field of view of the system is 8°~16°. The zoom lens consists of eight lenses with two aspherical surfaces, so it has the advantages of low cost and simple structure . The design results show that the modulation transfer function (MTF) of the zoom system is higher than 0.7 at cut off frequency of 38 lp/mm. The optical performance at all fields of view and all zooming conditions is close to the diffraction- limited image, and the distortion is less than 3% . So the zoom optical system presents a good image quality, and can meet users′ requirements.