印刷电路板光学检测用多角度光源

印刷电路板的表面缺陷光学检测是利用线阵CCD扫描获取PCB图像,再经过后续处理,找出PCB的表面缺陷。而获取高质量的图像需要一种分布均匀大功率线状光源。介绍了CCD扫描获取PCB图像的原理以及利用多组线光搭建多角度检测光源的设计原理和方法,并进行了理论分析和试验测试,包括在PCB表面图像检测中的应用。     

基于光电检测技术的电缆材料缺陷检测系统

采用在测量上广泛使用的光电转换器件线阵CCD技术,完成了电缆材料缺陷检测系统的总体方案设计。基于DSO的电缆材料缺陷检测系统在平行光的照射下,通过线阵CCD控制电路获得电缆材料缺陷信号,使用虚拟示波器DSO-2902对一维缺陷信号进行采集、传输,借助于计算机进行分析处理,从而精准地检测出缺陷。     

基于线阵CCD的交通信息采集和检测系统设计与实现

设计并实现了一种基于线阵CCD的交通信息采集和检测系统.该系统利用线阵CCD连续快速记录通过检测断面的车辆的线阵图像,并从该序列线阵图像中获取车牌号码、车辆存在、车辆速度、车辆类型、交通占有率和流量等各种交通参数,并通过TCP/IP协议向监控中心实时传递需要的数据信息.与传统的视频检测系统相比,该系统具有实时性高,检测准确,功能丰富等优点,在实际工程中使用效果良好.     

基于Ethernet的线阵CCD数据采集系统

设计了一种基于Ethernet的线阵CCD数据采集系统,通过FPGA对线阵CCD输出的数据进行采集,并通过在FPGA生成的nios2软核中移植μClinux构建具有网络功能的嵌入式系统,然后通过Ethernet将线阵CCD数据传输到上位机.详细介绍了整个数据采集系统的硬件系统和软件,系统的设计和上位机接收软件的设计.实现了基于Ethernet线阵CCD图像采集,传输以及图像的接收.     

线阵CCD测量系统的镜头畸变校正新方法

提出了一种线阵CCD测量系统镜头畸变校正的新方法.用线阵CCD相机及经纬仪组合体,对空间周期黑白条纹图像照相,通过图像处理和matlab曲线拟合建立图像像素坐标与无镜头畸变的理想像素坐标的关系式,即畸变校正函数.利用畸变校正函数可校正线阵CCD镜头畸变.将该方法应用于线阵CCD散布正交交汇测量系统后(两相机间距为1 561 mm),测量误差由畸变校正前5 mm提高到畸变校正后的0.9 mm.实验结果表明,用该方法进行镜头畸变校正后,线阵CCD散布测量系统的精度得到了显著的提高.     

基于DSP和线阵CCD外螺纹几何参数非接触测量方法研究

为了提高外螺纹尺寸检测的精度并实现自动化测量,文章提出了基于线阵CCD的非接触测量方法,建立了包括图像数据自动采集和尺寸计算的测量系统,该系统通过控制高精度的线阵CCD扫描外螺纹在平行光场中的投影并结合光电编码器来获取螺纹图像。文章详细介绍了线阵CCD驱动电路的实现,以TMS320F2812为信号处理器的线阵CCD在线测量系统的硬件结构与软件设计。     

图像拼接在塑料薄膜疵点检测系统中的应用

本文将图像拼接技术引入塑料薄膜疵点检测系统,在待检物幅面较宽的情况下,有效解决了单CCD相机难以满足检测精度要求而采用的多CCD相机采集图像的配准融合的问题,克服多线阵CCD机械拼接和光学拼接对拼接装置要求高,难度大的困难,实现宽幅待检图像的无缝拼接。     

CCD线阵象传感器

一、引言CCD线阵象传感器广泛用于传真,光符识别(OCR)、工业测量等办公室自动化(OA)和工厂自动化(FA)领域.尤其是作为读取传真原稿的光电变换器件正趋向实用化.最近,传真技术向高分辨率和高速方向迅速发展,从而对读取速度更快的多象素CCD线阵象传感器产生了迫切的需求.此外利用其高精度,高分辨特性,CCD还广泛用于工件尺寸、形状、厚度、位置及缺陷等的非接触式测量与检验.     

线阵CCD航空遥感模拟器的研究

为克服线阵CCD航空遥感器研制周期较长、无法进行前期系统联调工作的困难,设计了一种基于VC界面与现场可编程器件FPGA的线阵CCD航空遥感模拟器.整个系统通过VC仿真界面作为人机操作平台,完成指令、信息的交互;以FPGA作为模拟线阵CCD相机的核心器件,根据相应的指令和行同步信号、帧同步信号,按照线阵CCD相机的输出时...     

基于线阵CCD的多表面焦点偏移测量

在显微成像过程中,焦点偏移对长时间的活细胞观测等应用有很大影响,自动对焦技术是解决该问题最有效的技术手段之一。反射式的主动式表面偏移测量是显微镜实现自动对焦的关键,但是在存在多个表面反射的情况下如何进行准确的焦点偏移测量仍是需要解决的一个问题。本文提出了一种针对多表面反射的焦点偏移测量方法,该方法采用线阵CCD对反射光斑进行成像,不同表面反射回来的光斑在线阵CCD上可以很好的区分,通过窗口加权质心法够精确地测量所需要的表面反射光斑在CCD上的位移,从而精确测定焦点偏移,在样品干燥和样品湿润的情况下测量精度分别达到106 nm和111 nm。     

基于GPS和RFID技术的智能巡检系统

针对企业生产设备的巡检工作中存在人为的错巡、漏巡等问题,设计实现了一种基于GPS和RFID技术的智能巡检系统。该系统以计算机为依托构建中央信息处理系统CIPS（Central Information Processing System）,以PocketPC作为巡检终端PS（Portable Station）,采用SQL Server 2000关系型数据库和SQL Server CE3.0嵌入式数据库技术,集RFID技术、GPS定位技术、信息管理、信息传输等多项技术于一体,完成信息在CIPS和PS之间的交互,实现巡检信息的综合处理。     

Structural Modifications to Polystyrene via Self‐Assembling Molecules

We have previously reported that small quantities of self‐assembling molecules known as dendron rodcoils (DRCs) can be used as supramolecular additives to modify the properties of polystyrene (PS). These molecules spontaneously assemble into supramolecular nanoribbons that can be incorporated into bulk PS in such a way that the orientation of the polymer is significantly enhanced when mechanically drawn above the glass‐transition temperature. In the current study, we more closely evaluate the structural role of the DRC nanoribbons in PS by investigating the mechanical properties and deformation microstructures of polymers modified by self‐assembly. In comparision to PS homopolymer, PS containing small amounts (≤ 1.0 wt.‐%) of self‐assembling DRC molecules exhibit greater Charpy impact strengths in double‐notch four‐point bending and significantly greater elongations to failure in uniaxial tension at 250 % prestrain. Although the DRC‐modified polymer shows significantly smaller elongations to failure at 1000 % prestrain, both low‐ and high‐prestrain specimens maintain tensile strengths that are comparable to those of the homopolymer. The improved toughness and ductility of DRC‐modified PS appears to be related to the increased stress whitening and craze density that was observed near fracture surfaces. However, the mechanism by which the self‐assembling DRC molecules toughen PS is different from that of conventional additives. These molecules assemble into supramolecular nanoribbons that enhance polymer orientation, which in turn modifies crazing patterns and improves impact strength and ductility.     

Cover Picture: Structural Modifications to Polystyrene via Self‐Assembling Molecules (Adv. Funct. Mater. 3/2005)

The cover shows tensile failure of a sample of pure polystyrene (left), and a polystyrene sample with greater impact strength containing 1% by weight of dispersed nanoribbons (right), as reported in work by Stupp and co‐workers on p. 487. The nanoribbons are formed by self‐assembly of molecules known as dendron rodcoils (DRCs) in styrene monomer, resulting in the formation of a gel. This gel can then be polymerized thermally. We have previously reported that small quantities of self‐assembling molecules known as dendron rodcoils (DRCs) can be used as supramolecular additives to modify the properties of polystyrene (PS). These molecules spontaneously assemble into supramolecular nanoribbons that can be incorporated into bulk PS in such a way that the orientation of the polymer is significantly enhanced when mechanically drawn above the glass‐transition temperature. In the current study, we more closely evaluate the structural role of the DRC nanoribbons in PS by investigating the mechanical properties and deformation microstructures of polymers modified by self‐assembly. In comparision to PS homopolymer, PS containing small amounts (≤ 1.0 wt.‐%) of self‐assembling DRC molecules exhibit greater Charpy impact strengths in double‐notch four‐point bending and significantly greater elongations to failure in uniaxial tension at 250 % prestrain. Although the DRC‐modified polymer shows significantly smaller elongations to failure at 1000 % prestrain, both low‐ and high‐prestrain specimens maintain tensile strengths that are comparable to those of the homopolymer. The improved toughness and ductility of DRC‐modified PS appears to be related to the increased stress whitening and craze density that was observed near fracture surfaces. However, the mechanism by which the self‐assembling DRC molecules toughen PS is different from that of conventional additives. These molecules assemble into supramolecular nanoribbons that enhance polymer orientation, which in turn modifies crazing patterns and improves impact strength and ductility.     

SMT组装质量检测中的AOI技术与系统

介绍在微电子表面组装技术 (SMT)中应用的自动光学检测 (AOI)技术与系统的基本概况 ,并对SMT组装质量AOI技术发展趋势进行了分析     

LD阵列封装误差对空心导管均匀性的影响

为了提高空心导管激光二极管(LD)抽运耦合系统的性能,采用理论分析和ZEMAX仿真模拟的方法研究了LD阵列封装误差对空心导管抽运耦合系统均匀性的影响.研究发现,当LD阵列中子光束经过空心导管后分割和叠加次数越多时,光束指向误差对空心导管的均匀性影响越小.在此基础上提出了空心导管LD抽运耦合系统的设计中对LD阵列光束准直的原则.结果表明,根据实际情况决定LD阵列中快慢轴方向准直后发散角的大小,以保证快慢轴方向的光束经过空心导管后能够有适当的反射和叠加次数,从而实现较高的耦合效率和抗LD阵列封装误差影响的能力.该研究可用于指导该类空心导管LD抽运耦合系统的设计.     

显微拉曼光谱法对多孔硅热导率的研究

多孔硅优良的热学性能使其成为MEMS领域新兴的热绝缘材料。文中采用一种简便且无损的多孔硅热导率测量技术——显微拉曼光谱技术对电化学腐蚀法制备的不同孔隙率和厚度的多孔硅试样热导率进行了测量,结果表明在多孔硅的拉曼谱峰位置与其温度间存在线性对应关系。在所有样品中,厚度为110μm空隙率为65%的多孔硅显示出最好的绝热性能,其热导率为0.624W/mK。且随多孔硅孔隙率和厚度的减小,其热导率有迅速增加的趋势(厚度和孔隙率为9μm和40%时,其热导率升至25.32W/mK)。     

基于嵌入式Web服务器的科学级CCD数据采集系统

提出了基于嵌入式Web服务器的科学级CCD数据采集系统设计的新方法，并以ARM微处理器和嵌入式Linux为平台，结合光纤传输模块实现了数据采集。试验表明，该系统可实现对科学级CCD进行远程数据采集和高效数据传输，数据采集距离可达100m以上，数据传输速率可达8MHz，并具有抗干扰能力强、不受传输距离限制等特点。     

基于球心拟合的多边激光跟踪系统自标定方法

随着大尺寸工件和设备的制造加工以及装配的精度要求提高,对工件加工装配过程进行测量的测量系统精度要求也有所提高。多边法激光跟踪三维坐标测量系统只利用距离测量数据解算空间点坐标,能够避免激光跟踪仪角度测量带来的误差。文中提出了一种通过在跟踪仪测头挂载夹具进行球心拟合来获取跟踪仪测量原点的方式进行系统自标定,并辅以移站的方式,可使用两台激光跟踪仪构建四站多边法激光跟踪三维坐标测量系统。另外,文中还尝试了三站系统的构建。实验证明,四站系统将对标称长度1000.943 mm位于约20 m处的标准尺长度测量误差由最大110 μm减小至28 μm,三站系统将对标称长度969.045 mm位于约7.5 m处的标准尺长度的测量误差由最大67 μm减小至21 μm,相较于单台跟踪仪提高了精度,相较于传统多边系统降低了测站数量和成本,能够在工业现场实现高精度三维坐标测量。     

进料的质量控制

文中简单介绍供应商的质量控制,重点阐述进料的首件检验和进料批的检验,以确保进料符合规定要求,预防不会格品进入工序进行加工或装配,从而减少购货引起的经济损失。     

Structure and photoluminescence properties of InN films grown on porous silicon by MOCVD

In this work, indium nitride (InN) films were successfully grown on porous silicon (PS) using metal oxide chemical vapor deposition (MOCVD) method. Room temperature photoluminescence (PL) and field emission scanning electron microscopy (FESEM) analyses are performed to investigate the optical, structural and morphological properties of the InN/PS nanocomposites. FESEM images show that the pore size of InN/PS nanocomposites is usually less than 4 μm in diameter, and the overall thickness is approximately 40 μm. The InN nanoparticles penetrate uniformly into PS layer and adhere to them very well. Nitrogen (N) and indium (In) can be detected by energy dispersive spectrometer (EDS). An important gradual decrease of the PL intensity for PS occurs with the increase of oxidation time, and the PL intensity of PS is quenched after 24 h oxidization. However, there is a strong PL intensity of InN/PS nanocomposites at 430 nm (2.88 eV), which means that PS substrate can influence the structural and optical properties of the InN, and the grown InN on PS substrate has good optical quality.