为了完成对远近不同目标的观测瞄准,采用能调焦的光学系统。由于外调焦光学系统的筒长长,仪器的长度在调焦过程中发生变化,调焦中产生较大的瞄准误差和密封性不好等缺点而派生出了弥补其不足的内调焦光学系统。这种光学系统构成的仪器被广泛地应用在国防、工业生产的加工、测量、精密实验室中。对于内调焦光学系统的设计,同其 In order to complete the observation of different targets of near and far aiming, the use of focusing optical system. Due to the length of the outer focusing optical system tube, the length of the instrument changes in the focusing process, the focus produced a larger error and poor sealing ailments and other shortcomings derived from the inadequate to make up for the focal optics system. The optical system constituted by the instrument is widely used in national defense, industrial production processing, measurement, precision laboratory. For internal focusing optical system design, with its