非球面检测中偏心光束对焦系统设计

Automatic Focusing System Design of Eccentric Beam in Aspheric Surface Measuring Technology

针对常规非球面检测技术存在的问题,特别是测量高精度工件表面具有一定的局限性,提出一种非接触式测量技术,即自动对焦测量技术。自行设计了一套偏心光束对焦系统。光路采用激光作为光源,一维位置敏感器件PSD作为光电探测器。激光、柱面平凸透镜和反射镜构成偏心光束对焦光路。电路分为PSD信号处理电路和电动机驱动电路,具有电压放大、消除地面干扰和滤波等作用。

In order to improve aspheric surface measuring accuracy, which influences the aspheric machining accuracy of the workpiece, in this paper, a non- contact measuring technology, automatic focusing system, is presented. We have designed the optical path and circuit system to realize automatic focusing based on eccentric beam. The optical path consists of the laser, cylindrical planoconvex lens and reflector. The light - sensitive detector adopts the one - dimensional position sensitive device PSD. And the circuit includes two parts, PSD signal processing circuit and motor drive circuit. The experiments results show that： the designed system can meet the requirement of automatic focusing well.