针对红外目标探测等**应用的实际需求, 为了扩大对目标的搜索范围, 设计了 8～12 μm红外波段的 20×连续变焦光学系统。该系统采用 320×240非制冷焦平面红外探测器, 在 15～300 mm范围内实现连续变焦, F数为 2。系统结构简单, 仅由 6片透镜组成, 并仅引入 1个非球面校正系统像差。在空间频率为 16 lp/mm处, 变焦范围内的 MTF调制传递函数均在 0.45以上, 接近衍射极限, 像质优良, 像面稳定, 可用于坦克红外观瞄系统。

Aiming at actual needs of infrared target detection and other military applications, in order to expand the search scope of targets, an infrared continuous zoom optical system of 20× zoom ratio for 8-12 μm wave-band is designed in this paper. For 320×240 pixels uncooled infrared focal plane arrays, the focal length from 15 to 300 mm could be changed continuously and the F number is 2. Moreover, the system’s structure is simple, which only consists of six lenses and one aspherical surface is applied to correct aberrations. At the spatial frequency 16 lp/mm, the MTF curves in the whole zooming range are all above 0.45 which are closed to diffraction limited curve. The image quality is perfect and the stability of image plane is well. Meanwhile, this system can be applied to infrared observing and aiming optical system of Tank.