英语翻译是论文的英文翻译部分,大约三千字左右

变焦系统在函数投影类型的正射投影仪中得到了广泛的应用.本文分析了二元变焦核的特性,讨论了应用于正射投影仪的变焦系统的设计思想,并且给出了具有二个变焦系统的设计实例.
【英文摘要】 The zoom system is applied widely in the orthoprojector,working on the principle of the functional or the photographic projection,In this paper the characteristics of the vari-focal kernel with two elements is analysed and the design idea of the zoom system applied to orthoprojectors is described,Futhermore,an example of design with two zooms is given