CR扫描仪激光扫描光学系统的设计  

Design of laser scanning optical systems for computed radiography

作　　者：郑猛[1] 冯其波[1] 邵双运[1] 丁克勤[2] 

机构地区：[1]北京交通大学理学院,北京100044 [2]中国特种设备检测研究院,北京100013

出　　处：《光学精密工程》2010年第1期21-28,共8页Optics and Precision Engineering

基　　金：十一五国家科技支撑计划01课题资助项目(No.2006BAK02B01-02-01)

摘　　要：设计了一种适合于计算机X射线扫描仪的新型激光扫描系统,其空间分辨率为10lp/mm。针对常用扫描机构的不足,用五角棱镜和聚焦物镜组成扫描臂取代传统的Fθ镜头,利用成像板的柔韧性实现圆弧形进片,扫描臂同时作为接收器收集激发出的荧光,从而简化系统结构,提高系统性能。利用所设计的光学系统,分析了激光光点大小对分辨率的影响,结果显示光点越小,系统分辨率越高。分析了系统中影响激光光点大小的因素,在高转速条件下对扫描臂进行了有限元仿真,计算了当入射光与五角棱镜入射面不垂直及五角棱镜存在安置误差时,对激光光点大小的影响。结果显示光点直径最大相对变化量为0.07%,表明所设计的激光扫描光学系统具有一定的容差性和实用性。通过实验验证了所研制扫描仪的性能,结果表明图像具有良好的视觉效果,能够满足工业检测要求。A new high-performance laser scanning optical system for the Computed Radiography（CR）with a spatial resolution of 10 lp/mm was designed.In view of the performance difference of scanning methods,a scanning arm composed of a pentagonal prism and a scanning object lens was presented to replace the Fθ lens,and then a circular imaging plate was presented to implement the transport mechanism by bending film movement.As the scanning arm can collect synchronously luminescence as a receiving device,the system designed by this method has a simple structure and good performance.The effect of spot sizes on resolution was analyzed and the results show that the smaller the spot size is,the higher the system resolution will be.Many factors effecting on the spot sizes were analyzed in this system,and the dynamic performance of the scanning arm was simulated by using the finite element method in high speed rotating.Furthermore,the influence of an incident light out of the vertical incident flat of pentagonal prism and pentagonal prism displacement errors on the spot sizes were calculated,and the calculation reveals that the largest change of the diameter for the spot sizes is 0.07%,which proves that the system has good tolerance and practicability.Experiments were carried out to verity the performance of laser scanner,and the results indicate that the images obainted have good visual effects and can meet the requirements of industrial inspections.

关 键 词：激光扫描光学系统 有限元分析 五角棱镜 扫描臂 

分 类 号：TH774[机械工程—仪器科学与技术] R814.42[机械工程—精密仪器及机械]