LED光电参数在线测试分选系统研究
|
摘要
随着发光二极管(LED)应用范围的扩大，用户对LED产品质量有了更高的要求，尤其要求LED发光亮度和波长有一致性，所以对LED光、色、电参数的测量也提出了更高的要求。一些企业由于检测水平低，仪器配套性差，检测精度低，产品性能互相之间不可比对；一些企业所依赖的进口测试、分选设备价格很高。这种状况如果长此下去，对我国LED产业的结构和发展十分不利。因此，自行研究LED光、色、电参数在线快速测试及自动分选系统对促进我国的LED产业发展和提高LED的产品质量具有重要的意义。本文主要工作如下：
1．利用光谱测试仪中线阵CCD的各个像素与LED波长的对应关系，实现了全光谱同时测量。LED光源经线阵CCD、PCI-6023E数据采集卡转换后送入计算机，处理后即可获得光谱功率分布函数P(λ)，从而可计算出LED光源色度坐标、纯度、峰值波长以及主波长的值。
2．设计了LED在线测试电路，通过此电路与PCI数据采集卡之间的通信快速测量LED电学参数；设计了测试系统与自动分选系统之间的通信接口电路，通过测试系统与自动分选系统之间的通信可完成LED各项参数的在线测试，实现了LED测试与分选的自动生产流水线。所设计的LED自动分选系统由LED基本输送装置(圆盘振动输送机、直线振动输送机)、等间隔喂入装置、送料装置、通电夹紧装置和分选装置几部分组成；LED在线测试技术是本论文的重点，对分选系统只作简要介绍。
3．采用最小二乘多项式拟合LED峰值波长与CCD像素坐标曲线，对实验结果的分析表明：与线性拟合相比，多次拟合可有效提高测量结果的精确度。
4．采用曲线拟合和查表逐次逼近法计算LED主波长，通过对这两种方法的比较，选用查表逐次逼近法计算LED主波长，可控制主波长重复测量误差小于1nm。
5．利用LabVIEW软件开发平台，通过应用程序将计算机与专用硬件结合起来，完成对被测量的采集、计算分析等功能，并通过计算机处理给出分选信号，实现了按LED光、色、电参数进行自动分选。
最后给出了利用本系统测量LED参数的测试结果，分析了影响LED测量精度的因素，并在此基础上提出了一些改进意见和方法。
With the expansion of LED's application scope, the user has higher requirements on LED product quality, especially on LED brightness and wavelength consistency. Therefore, the measurement of LED parameters has higher demand. Because of the poor level of equipment matching, low detection accuracy, some enterprises' product performance can not be compared to each other. Some companies rely on the import testing and sorting equipment, thus the cost of production is very high. It will have unfavorable influence on China's LED industry structure and development in the long run. Therefore, researching on fast on-line testing of LED optoelectronic parameters and automatic sorting systems which is significant for promoting china's industrial development and enhancing LED product quality. The major work of this paper are as follow:
1. The corresponding relations between the various linear CCD pixel of spectrum tester and LED wavelength is employed to realize the full spectrum measurement at the same time. The LED light source with the conversion of linear CCD and PCI-6023E is sent to computer, and processed to get the spectrum power distribution function P (λ), which can be used to calculate LED light source chromaticity coordinates, purity, peak wavelength and dominant wavelength values.
2. LED on-line test circuit is designed, LED electrical parameters can be rapidly measured through the communication between the circuit and PCI data acquisition card. Communications interface circuit between the testing system and automatic sorting system is designed. It can realize automatic production pipelining of LED testing and automatic sorting through the communication between the testing system and sorting system. LED automatic sorting system includes several parts: LED transportation equipment, interval feeding equipment, feeding equipment, electricity clamping equipment and sorting equipment. This paper focuses on on-line testing technology of LED, the sorting system only for brief.
3. A least squares polynomial fits LED's peak wavelength and CCD pixel coordinates curve, the analysis of the experimental results shows that: Compared with the linear fitting, Polynomial fitting can effectively improve the precision of the testing results.
4. Curve fitting and Look-up successive approximation method are employed to calculate LED's dominant wavelength. Through the comparison of two methods, look-up table method of successive approximation is exported to calculate dominant wavelength, the dominant wavelength measurement error is less than 1 nm.
5. Using LabVIEW software development platform, it completes the acquisition, calculation and analysis capabilities of the measured parameter through the combination of application program and hardware. The signal of the LED light, color, electrical parameters for automatic sorting is given by the testing system.
Finally, the test results which is obtained by the system are given. The paper analyzes the factors which have impact on the LED testing accuracy, furthermore, a number of improvements and methods are raised.
1．利用光谱测试仪中线阵CCD的各个像素与LED波长的对应关系，实现了全光谱同时测量。LED光源经线阵CCD、PCI-6023E数据采集卡转换后送入计算机，处理后即可获得光谱功率分布函数P(λ)，从而可计算出LED光源色度坐标、纯度、峰值波长以及主波长的值。
2．设计了LED在线测试电路，通过此电路与PCI数据采集卡之间的通信快速测量LED电学参数；设计了测试系统与自动分选系统之间的通信接口电路，通过测试系统与自动分选系统之间的通信可完成LED各项参数的在线测试，实现了LED测试与分选的自动生产流水线。所设计的LED自动分选系统由LED基本输送装置(圆盘振动输送机、直线振动输送机)、等间隔喂入装置、送料装置、通电夹紧装置和分选装置几部分组成；LED在线测试技术是本论文的重点，对分选系统只作简要介绍。
3．采用最小二乘多项式拟合LED峰值波长与CCD像素坐标曲线，对实验结果的分析表明：与线性拟合相比，多次拟合可有效提高测量结果的精确度。
4．采用曲线拟合和查表逐次逼近法计算LED主波长，通过对这两种方法的比较，选用查表逐次逼近法计算LED主波长，可控制主波长重复测量误差小于1nm。
5．利用LabVIEW软件开发平台，通过应用程序将计算机与专用硬件结合起来，完成对被测量的采集、计算分析等功能，并通过计算机处理给出分选信号，实现了按LED光、色、电参数进行自动分选。
最后给出了利用本系统测量LED参数的测试结果，分析了影响LED测量精度的因素，并在此基础上提出了一些改进意见和方法。
With the expansion of LED's application scope, the user has higher requirements on LED product quality, especially on LED brightness and wavelength consistency. Therefore, the measurement of LED parameters has higher demand. Because of the poor level of equipment matching, low detection accuracy, some enterprises' product performance can not be compared to each other. Some companies rely on the import testing and sorting equipment, thus the cost of production is very high. It will have unfavorable influence on China's LED industry structure and development in the long run. Therefore, researching on fast on-line testing of LED optoelectronic parameters and automatic sorting systems which is significant for promoting china's industrial development and enhancing LED product quality. The major work of this paper are as follow:
1. The corresponding relations between the various linear CCD pixel of spectrum tester and LED wavelength is employed to realize the full spectrum measurement at the same time. The LED light source with the conversion of linear CCD and PCI-6023E is sent to computer, and processed to get the spectrum power distribution function P (λ), which can be used to calculate LED light source chromaticity coordinates, purity, peak wavelength and dominant wavelength values.
2. LED on-line test circuit is designed, LED electrical parameters can be rapidly measured through the communication between the circuit and PCI data acquisition card. Communications interface circuit between the testing system and automatic sorting system is designed. It can realize automatic production pipelining of LED testing and automatic sorting through the communication between the testing system and sorting system. LED automatic sorting system includes several parts: LED transportation equipment, interval feeding equipment, feeding equipment, electricity clamping equipment and sorting equipment. This paper focuses on on-line testing technology of LED, the sorting system only for brief.
3. A least squares polynomial fits LED's peak wavelength and CCD pixel coordinates curve, the analysis of the experimental results shows that: Compared with the linear fitting, Polynomial fitting can effectively improve the precision of the testing results.
4. Curve fitting and Look-up successive approximation method are employed to calculate LED's dominant wavelength. Through the comparison of two methods, look-up table method of successive approximation is exported to calculate dominant wavelength, the dominant wavelength measurement error is less than 1 nm.
5. Using LabVIEW software development platform, it completes the acquisition, calculation and analysis capabilities of the measured parameter through the combination of application program and hardware. The signal of the LED light, color, electrical parameters for automatic sorting is given by the testing system.
Finally, the test results which is obtained by the system are given. The paper analyzes the factors which have impact on the LED testing accuracy, furthermore, a number of improvements and methods are raised.
引文
[1] 邵嘉平，郭文平，胡卉等．GaN基绿光LED材料蓝带发光对器件特性的影响．半导体学报，2004，25 (11)：1496．
[2] 尹长安 赵成久等，白光LED最新进展，发光学报[J]，Vol．21，No．4，Dec．2000，380-383．
[3] 潘建根．LED光色电综合性能分析测试原理，液晶与显示[J]，Vol．18，No．2，April．2003，137-140．
[4] 苏哲，董占民，韩立，等．发光二极管外延片质量控制的新方法．半导体学报，2002，23 (12)：1295．
[5] 张万生，粱春广．可见光LED的进展：超高亮度LED及应用(二)．半导体情报，1997，34 (4)：9-17．
[6] 沈海平，潘建根，冯华君．普通照明LED标准中的产品分类问题[A]2006中国 (深圳) 国际半导体照明论坛．
[7] 蔡伟智．LED测量精度影响因素的探讨[A]．第十届全国LED产业研讨与学术会议，2006
[8] MacLellan, Chris. Perspectives on measurement of LED illumination sources[J]. Photonics Spectra, v 38, n 9, September, 2004, p 69-70.
[9] 叶荣南．LED测量误差探讨[A]．2007第四届中国国际半导体照明论坛．
[10] 杨亦红．发光二极管特征参数分析及其测试技术研究[硕士学位论文]，浙江大学硕士学位论文，2004．
[11] Cheng, Jian-Bo. Chromatic property measurement system for LED[J], Proceedings of SPIE The International Society for Optical Engineering, v 5941, 2005, p 1-10.
[12] Commission Internationale de I' Eclairage. Measurement of LEDs[S]. publication CIE 127-1997: 19.
[13] 蒋大鹏．白光LED及相关照明器件技术研究，中国科学院长春光学精密机械与物理研究所博士论文，2003．
[14] http://www.led8.com.
[15] 吴继宗，叶关荣．光辐射测量[M]．北京：机械工业出版社，1992．209-211．
[16] 鲍超，发光二极管测试技术与标准．物理学与高新技术[J]，2003 (32)：5，p319-324．
[17] CIE publication 127-1997, measurement of LEDs[S].
[18] 金尚忠，王东辉．发光二极管光谱参数测试方法的研究[J]．光电子*激光，2002 (13)：8，p824-825．
[19] CIE, Colorimetry, Second Edition, CIE Publication 15. 2-1986.
[20] 张丽琼．快速多通道发光二极管光谱参数测试仪的研制及应用，浙江大学硕士学位论文，2004．
[21] Miller, C. Cameron. Standardization of LED measurements[J]. Photonics Spectra, v 38, n 9, September, 2004, p 68.
[22] Guild, J. (1931). The colorimetric properties of the spectrum. Philosophical Transactions of the Royal Society of London, A230, 149-187.
[23] Wright, W. D. (1928). A re-determination of the trichromatic coefficients of the spectral colours. Transactions of the Optical Society, 30, 141-164.
[24] 汤顺青，色度学，北京理工大学出版社[M]．1990，79-80．
[25] John A, McNeill. Light Emitting Diodes characteristics, Sample Lab, 1997.
[26] Park, Seongchong. Preparation of a standard light-emitting diode (LED) for photometric measurements by functional seasoning[J]. Metrologia, v 43, n 3, Jun 1, 2006, p 299-305.
[27] Bellmeyer, Jr., Fred W., and Saltzman, Max. Principles of Color Technology, 2nd ed. New York: John Wiley and Sons, 1981.
[28] 胡莹，基于色度学的波长分级检测及自动分选系统研究，武汉理工大学硕士学位论文．
[29] Jin, Shangzhong. LED automatic grader[J]. Proceedings of SPIE-The International Society for Optical Engineering, v 3558, 1998, p 336-338.
[30] 扬乐平，等．LabVIEW程序设计与应用[M]．北京：电子工业出版社，2001．
[31] Wang, Donghui. Fast and high-accuracy spectral measurements of LED by linear CCD sensor and software calibration[J]. Proceedings of SPIE-The International Society for Optical Engineering, v 5633, Advanced Materials and Devices for Sensing and Imaging Ⅱ, 2005, p 578-584.
[32] 唐奕，陈海清等．线阵CCD多通道光谱仪及其应用．华中科技大学学报，2002，30 (10)：96-98．
[33] CIE, Method of Measuring and Specifying Color Rendering Properties of Light Sources, CIE Publication 13. 3-1995.
[34] 潘建根，闵芳胜．测量LED用高精度光度探头及其性能评价[M]．液晶与显示，2005 (20)：2，p150-151．
[35] 冯一飞，鲍超．LED光度测量校准的色修正系数的确定[M]．光学仪器，2006 (28)：2，p12-13．
[36] Muray C. Blue LED photometry. ProcSPIE, Illumination and Source Engineering, 1998, 342 3428: 115.
[37] 潘建根，沈海平，冯华君 光谱校正积分光度法测量蓝光LED光通量[M] 半导体学报 2006 (27)：5，p 932-933．
[38] 王庆有．CCD应用技术．天津：天津大学出版社，2000．
[39] Spectral Products Catalog, Spectral Products company, 2003.
[40] 武自芳．微机控制系统及其应用[M]．西安：西安交通大学出版社，2002．
[41] 沈兰荪．数据采集技术[M] 中国科学技术大学出版社 1990．
[42] 李贵山，陈金鹏．PCI局部总线及其应用[M]．西安：西安电子科技大学出版社，2003，2
[43] ADLink Technology Inc. 9112 Series Multi function DAS Cards User's Guide[Z]. ADLink Technology Inc, 2002.
[44] 王林涛，李开成．低噪声光电检测电路的设计和噪声估算．武汉理工大学学报，2001，3 (23)：16-18．
[45] 黄贤园．LED光电参数智能化测试研究[硕士学位论文]，重庆大学硕士学位论文．
[46] Park, Seung-Nam, A new approach to preparation of standard LEDs for luminous intensity and flux measurement of LEDs[J]. Proceedings of SPIE - The International Society for Optical Engineering, v 6355, Advanced LEDs for Solid State Lighting, 2006, p 63550G.
[47] 林卫国．LED光谱电性参数测试技术的研究与开发[硕士学位论文]，武汉理工大学硕士 学位论文．
[48] 李伯全，潘海彬，罗开玉．LabVIEW平台下基于DLL的普通数据采集卡的驱动[J]．仪表技术，2004，2：11-12．
[49] Spectral Products Inc. SM32Pro SDK Users Manual[Z]. 2006, 2.
[50] 沈杭城，等．多通道快速光谱仪的波长定标[M]．光学仪器，2006 (28)：2 P52-55．
[51] 李庆杨，王能超，易大义．数值分析[M]．武汉：华中科技大学出版社，2003．
[52] http://www-cvrl.ucsd.edu.
[53] 鲍超，超高亮度LED测量问题，液晶与显示[J]．2003，18 (4)，244-250．
[54] 代彩虹，于家琳．光源相关色温计算方法的讨论[J]．计量学报，2000，21 (3)，183-188
[55] 刑延，赵田冬．相关色温计算方法的优化[J]．浙江大学学报，1997，31 (5)．682-686．
[56] 陈焕庭，吕毅军，王亚军．曲线拟合计算LED光源色温[A]．第十届全国LED产业研讨与学术会议论文集，p108-110．
[57] 王宇方，扬志坚，丁晓民．用InGaN蓝光LED与YAG荧光粉制造自然白光LED[J]．高技术通讯，2002，07，77-79．
[58] Long, Xing-Ming, Development of multifunction LED measurement system[J]. Semiconductor Optoelectronics, v 28, n 2, April, 2007, p 179-182
[59] 雷玉堂，王庆有．光电检测技术．北京：中国计量出版社，1997 [24]．
[60] Oleksandr A Skydan, Francis lilley, Micael J. Lalor, and David R. Burton, Quantization error of CCD cameras and their influence. APPLIED OPTICS, 2003. 42 (26): 5302-5307.
[2] 尹长安 赵成久等，白光LED最新进展，发光学报[J]，Vol．21，No．4，Dec．2000，380-383．
[3] 潘建根．LED光色电综合性能分析测试原理，液晶与显示[J]，Vol．18，No．2，April．2003，137-140．
[4] 苏哲，董占民，韩立，等．发光二极管外延片质量控制的新方法．半导体学报，2002，23 (12)：1295．
[5] 张万生，粱春广．可见光LED的进展：超高亮度LED及应用(二)．半导体情报，1997，34 (4)：9-17．
[6] 沈海平，潘建根，冯华君．普通照明LED标准中的产品分类问题[A]2006中国 (深圳) 国际半导体照明论坛．
[7] 蔡伟智．LED测量精度影响因素的探讨[A]．第十届全国LED产业研讨与学术会议，2006
[8] MacLellan, Chris. Perspectives on measurement of LED illumination sources[J]. Photonics Spectra, v 38, n 9, September, 2004, p 69-70.
[9] 叶荣南．LED测量误差探讨[A]．2007第四届中国国际半导体照明论坛．
[10] 杨亦红．发光二极管特征参数分析及其测试技术研究[硕士学位论文]，浙江大学硕士学位论文，2004．
[11] Cheng, Jian-Bo. Chromatic property measurement system for LED[J], Proceedings of SPIE The International Society for Optical Engineering, v 5941, 2005, p 1-10.
[12] Commission Internationale de I' Eclairage. Measurement of LEDs[S]. publication CIE 127-1997: 19.
[13] 蒋大鹏．白光LED及相关照明器件技术研究，中国科学院长春光学精密机械与物理研究所博士论文，2003．
[14] http://www.led8.com.
[15] 吴继宗，叶关荣．光辐射测量[M]．北京：机械工业出版社，1992．209-211．
[16] 鲍超，发光二极管测试技术与标准．物理学与高新技术[J]，2003 (32)：5，p319-324．
[17] CIE publication 127-1997, measurement of LEDs[S].
[18] 金尚忠，王东辉．发光二极管光谱参数测试方法的研究[J]．光电子*激光，2002 (13)：8，p824-825．
[19] CIE, Colorimetry, Second Edition, CIE Publication 15. 2-1986.
[20] 张丽琼．快速多通道发光二极管光谱参数测试仪的研制及应用，浙江大学硕士学位论文，2004．
[21] Miller, C. Cameron. Standardization of LED measurements[J]. Photonics Spectra, v 38, n 9, September, 2004, p 68.
[22] Guild, J. (1931). The colorimetric properties of the spectrum. Philosophical Transactions of the Royal Society of London, A230, 149-187.
[23] Wright, W. D. (1928). A re-determination of the trichromatic coefficients of the spectral colours. Transactions of the Optical Society, 30, 141-164.
[24] 汤顺青，色度学，北京理工大学出版社[M]．1990，79-80．
[25] John A, McNeill. Light Emitting Diodes characteristics, Sample Lab, 1997.
[26] Park, Seongchong. Preparation of a standard light-emitting diode (LED) for photometric measurements by functional seasoning[J]. Metrologia, v 43, n 3, Jun 1, 2006, p 299-305.
[27] Bellmeyer, Jr., Fred W., and Saltzman, Max. Principles of Color Technology, 2nd ed. New York: John Wiley and Sons, 1981.
[28] 胡莹，基于色度学的波长分级检测及自动分选系统研究，武汉理工大学硕士学位论文．
[29] Jin, Shangzhong. LED automatic grader[J]. Proceedings of SPIE-The International Society for Optical Engineering, v 3558, 1998, p 336-338.
[30] 扬乐平，等．LabVIEW程序设计与应用[M]．北京：电子工业出版社，2001．
[31] Wang, Donghui. Fast and high-accuracy spectral measurements of LED by linear CCD sensor and software calibration[J]. Proceedings of SPIE-The International Society for Optical Engineering, v 5633, Advanced Materials and Devices for Sensing and Imaging Ⅱ, 2005, p 578-584.
[32] 唐奕，陈海清等．线阵CCD多通道光谱仪及其应用．华中科技大学学报，2002，30 (10)：96-98．
[33] CIE, Method of Measuring and Specifying Color Rendering Properties of Light Sources, CIE Publication 13. 3-1995.
[34] 潘建根，闵芳胜．测量LED用高精度光度探头及其性能评价[M]．液晶与显示，2005 (20)：2，p150-151．
[35] 冯一飞，鲍超．LED光度测量校准的色修正系数的确定[M]．光学仪器，2006 (28)：2，p12-13．
[36] Muray C. Blue LED photometry. ProcSPIE, Illumination and Source Engineering, 1998, 342 3428: 115.
[37] 潘建根，沈海平，冯华君 光谱校正积分光度法测量蓝光LED光通量[M] 半导体学报 2006 (27)：5，p 932-933．
[38] 王庆有．CCD应用技术．天津：天津大学出版社，2000．
[39] Spectral Products Catalog, Spectral Products company, 2003.
[40] 武自芳．微机控制系统及其应用[M]．西安：西安交通大学出版社，2002．
[41] 沈兰荪．数据采集技术[M] 中国科学技术大学出版社 1990．
[42] 李贵山，陈金鹏．PCI局部总线及其应用[M]．西安：西安电子科技大学出版社，2003，2
[43] ADLink Technology Inc. 9112 Series Multi function DAS Cards User's Guide[Z]. ADLink Technology Inc, 2002.
[44] 王林涛，李开成．低噪声光电检测电路的设计和噪声估算．武汉理工大学学报，2001，3 (23)：16-18．
[45] 黄贤园．LED光电参数智能化测试研究[硕士学位论文]，重庆大学硕士学位论文．
[46] Park, Seung-Nam, A new approach to preparation of standard LEDs for luminous intensity and flux measurement of LEDs[J]. Proceedings of SPIE - The International Society for Optical Engineering, v 6355, Advanced LEDs for Solid State Lighting, 2006, p 63550G.
[47] 林卫国．LED光谱电性参数测试技术的研究与开发[硕士学位论文]，武汉理工大学硕士 学位论文．
[48] 李伯全，潘海彬，罗开玉．LabVIEW平台下基于DLL的普通数据采集卡的驱动[J]．仪表技术，2004，2：11-12．
[49] Spectral Products Inc. SM32Pro SDK Users Manual[Z]. 2006, 2.
[50] 沈杭城，等．多通道快速光谱仪的波长定标[M]．光学仪器，2006 (28)：2 P52-55．
[51] 李庆杨，王能超，易大义．数值分析[M]．武汉：华中科技大学出版社，2003．
[52] http://www-cvrl.ucsd.edu.
[53] 鲍超，超高亮度LED测量问题，液晶与显示[J]．2003，18 (4)，244-250．
[54] 代彩虹，于家琳．光源相关色温计算方法的讨论[J]．计量学报，2000，21 (3)，183-188
[55] 刑延，赵田冬．相关色温计算方法的优化[J]．浙江大学学报，1997，31 (5)．682-686．
[56] 陈焕庭，吕毅军，王亚军．曲线拟合计算LED光源色温[A]．第十届全国LED产业研讨与学术会议论文集，p108-110．
[57] 王宇方，扬志坚，丁晓民．用InGaN蓝光LED与YAG荧光粉制造自然白光LED[J]．高技术通讯，2002，07，77-79．
[58] Long, Xing-Ming, Development of multifunction LED measurement system[J]. Semiconductor Optoelectronics, v 28, n 2, April, 2007, p 179-182
[59] 雷玉堂，王庆有．光电检测技术．北京：中国计量出版社，1997 [24]．
[60] Oleksandr A Skydan, Francis lilley, Micael J. Lalor, and David R. Burton, Quantization error of CCD cameras and their influence. APPLIED OPTICS, 2003. 42 (26): 5302-5307.