摘要
针对基于激光三角测距原理设计的显微镜自动对焦系统中,光斑在TFT-LCD面板上表面或者下表面聚焦时的鬼影以及打在金属丝上的光斑畸变问题,提出在焦平面附近调节相机快门和增益以消除鬼影,并根据相机快门时间动态变换光斑中心的求解方法。分析了光斑鬼影产生的原因和消除方法以及当光斑图像不同程度打在金属丝上时,导致光斑图像局部明显增强的特性,给出了求解光斑中心的方法。实验结果表明,光斑中心位置和离焦量线性拟合R的平方值为0.991,减少了激光三角测距法的非线性误差,实现了非接触快速对焦。
The microscope auto-focusing system is based on the laser triangulation ranging principle,which leads those problems including the ghosting matter when the light spot focusing on the upper surface or lower surface of TFT-LCD panel and the spot distortion of wire.It gives the methods about adjusting the shutter and gain around the focal plane,changing the spot center according to the dramatic-time-change of camera shutter.It researches the causes of the ghosting spot and provides the solutions.It also analyzes the characteristics of spot gray value partial increasing obviously caused by the spot image reflex to the wire inordinately.and gives approaches to get the spot center.The experiment result shows that square of R is 0.991 obtained by linearly fitting the defocusing amount and the light spot center position,which is verified in the experiment by applying analysis mentioned above,reducing the nonlinear error of the laser triangulation method and realizing the non-contact focusing efficiently.
出处
《微型机与应用》
2010年第21期37-41,共5页
Microcomputer & Its Applications
关键词
激光三角法
快门
鬼影
光斑中心
离焦量
laser-triangulation
shutter
ghost
spot center
defocusing amount
