激光衍射 CCD 测径系统

CCD Measuring System for Wire Diameter by Laser Diffraction

本系统用Ｈｅ－Ｎｅ激光器产生的激光束，经准直扩束后，垂直照射待测细丝，形成衍射条纹。然后用高分辩率线阵ＣＣＤ摄象机将衍射条纹（光强信号）转换成电信号，经Ａ／Ｄ转换将数据送入计算机，用最小二乘法将衍射条纹的光强分布精确地拟合出来，再根据有关衍射公式算出细丝直径。本文主要介绍光路设计、信号处理及软件设计。

The diffraction fringes were built by irradiating the measured wire normally with a expanded He-Ne laser beam. The CCD video camera with a high resolution recorded the diffraction fringes and transfered them to electric signals, which were processed through A/D converter in the computer. The wire diameter can be measured by fitting the computer data to the intensity distribution of the fringes with the least square method and according to the diffraction optics.