A Study On LED Sorting Machine

LED as a new light source is more and more applied in various fields, including the display, LCD panel backlighting, decorative lighting and general lighting. However, due to the characteristics of production process of LED, the electronic and optical properties of each LED are different, so its electrical parameters and optical parameters should be measured and classified accordingly. LED sorting machine based on the principle of classification is the specialized equipment that sorts LED. Some companies are condition that level of detection is low, and equipment is not compatible, low detection accuracy, product performance not comparable to each other; some enterprises rely on the foreign test and sorting equipment which costs so much. if the situation continues,that is very detrimental to the structure and development of chinese LED industry. Therefore, that research on our own LED's online -test and automatic sorting equipment which could promote the development of chinese LED industry and improve the quality of LED is great significant.The main LED's parameters and the conception are introduced .The ways and the principle of testing are analyzed . Specially the principle of the detecting LED's spectrum,the notice and the way of improvement accuracy of testing are detailed.All the study areas of this subject are confirmed.Then the designing of the machine is introduced. It includes the controlling part, testing part and software.The controlling system is realized by the technology of PC&PLC,PC controls instrument is used in the LED testing and PLC drives mechnical Part.The testing system uses High-accuracy CCD spectrometer and light intensity detector.Finally, the way of sorting of LED is discussed and studied.The parameters which selected as classifying parameters are confirmed,these parameters are positive voltage, luminous intensity ,dominant wavelength and chromaticity coordinates(for white LED).Actual measurement was done and show that results of classification are well , Meeting the design's requirements .The interface of the machine is clear and the structure is rational,it is convenient for testing and adjusting.