1.The principle of secondary spectrum is introduced and the equations of designing apochromatism objective lens based on wave aberration are presented.
介绍了二级光谱基本原理,给出了波差法设计复消色差镜方程组。
2.A physiotherapeutic apparatus for preventing and treating near sighted eye has a convex lens used as objective lens, lens cone, eyepiece, headgear and lens set.