THREE-MIRROR SYSTEM WITH A FOLDED MIRROR
折轴三反射镜成象光学系统结构研究

The three mirror system with a small folded mirror is discussed in the paper. It have thehigh MTF because the aberrations could be eliminated for the system with the three mirrors of theconic constants. Comparing with off--axial three mirror system, it is easy to be assembled. Thetechnique which controls the central obstructions in two places is also proposed.