近半个世纪以来，安装在车辆两侧的外置后视镜都是平面镜或球状凸面镜，这两种镜面要么盲区大，视野小，要么以景像变形求得扩大视野，都会不同程度地影响驾驶安全。清华大学高级技师李世卿经过长期钻研，发明了一种能根据使用要求消除盲区、扩大视野，又不造成景像过大变形的? For nearly half a century, the external rearview mirrors installed on both sides of the vehicle have been plane mirrors or spherical convex mirrors. Both types of mirrors have large blind spots and small fields of view, or they can be obtained by expanding the view with the deformation of the scene. Affect driving safety. After a long period of research, senior technical engineer Li Shiqing of Tsinghua University invented a method that can eliminate blind spots and expand the visual field according to the requirements of use, without causing excessive deformation of the scene.