LED Testing System Scheme Design And Signal Acquisition

As a result of LED's wide and bright application prospect, the requirement to LED's quality is higher and higher, so testing of LED's optical, electrical and color parameters is strict. In the past, the method distinguishing LED's quality and grading by naked eyes can't be satisfied with market requirement any more. In our home, many enterprises and institutes have developed all kinds of high level testing devices and instruments which cover LED's optical, electrical and color parameters testing. These products not only cover single parameter testing, but also cover multi-parameters testing; not only high speed and automation test, but multifunction with automation and high speed test and grad system. This paper brings forward a new test scheme based on the analyses of existing testing method and scheme. The new scheme can satisfy with different users and application's requirement, and the same time which can improve the test precise, repeatable, reliability and efficiency.Firstly, the paper analyzes LED's development condition, application field and test instrument's development status, and brings forward an optimized design scheme based on the sum-up and analyses.Secondly, it discusses that LED's parameters test principium and scheme demonstration, especially tells the spectral parameter testing principium and method of improving precise; the test principium of luminous flux and test method of stretch angle; test principium, matters and test method concerned improving precise of intensity.Thirdly, based on the demonstration and analyses, we finished optical road for the spectrum test; luminous flux test optical road, stretch angle test optical road, intensity test optical road and signal process electro-circuit. How to choose the key components, such as grating, CCD and photoelectric diode and how to calculate its parameters. The factors affect the test precise, stability and raise the mend method.Fourthly, the paper finished data acquisition, data process and software program based on the design and manufacture of optical road and electrical circuit. It realized the driver of acquisition card USB2004, CCD signal acquisition and data process. Use the software LabVIEW to realize the digital filter and the calculation of peak wavelength, intensity, luminous flux and electrical parameters; send out the signal of grading.Lastly, tells the calibration principium and the method of calibration. In order to...