Automatic Test Of Photoelectric Properties Of FED

As a new type of self-luminous flat-panel displays，Field emission display becomethe hotspot of research because of its advantages of high brightness and color fidelitylike CRT, lightweight portability like flat panel display. However, the technology andthe drive circuit of FED is not yet very mature, resulting in instability of FEDphotoelectric characteristics, and caused a lot of inconvenience to research FED.Therefore, it is beneficial to the performance of FED photoelectric for the design ofautomatic measurement system.In this paper, I according to FED own performance characteristics and flat-paneldisplay of the state testing standards, detailing introduce the test content, test methodsand test procedures of FED, also make certain demands on the test environment. Onthis basis, I design a set of automated testing equipment which can measure the mainperformance parameters of FED and process the test result in auto.Firstly, I introduce the basic principles and driving approach of FED fieldemission, and accordance with a series of national standard, introducing severalimportant test parameters and test procedures of FED，these parameter is formed bybrightness,contrast,uniformity,gray scale;the procedure is formed by provid testsignals,measure the parameter signal,handel the measured signal,display the handeldesignal. Then I introduce the measurement methods and measuring principle of theluminance meter, and propose the corresponding correction method for the cosine ofthe photoelectric sensor and the non-linear of the photoelectric collection system.The paper focuses on hardware design of the automatic test system, including astepper motor drive circuit, photoelectric collection circuit, AD converter circuit, USBtransmission circuit, so that the test system has highly test standard and testaccuracy,the accuracy of fix position is1mm and the rate of collection is12MHZ;also I adopt the modular approach to describe the software design program. Thesoftware design includes low-level driver and the upper control procedures. Low-leveldriver is mainly responsible for data collection from subordinate computer, the uppercontrol program is mainly responsible for the preparation of the interface of the hostcomputer, as well as the choice of test parameters.At last, I use this tester to measure the25-inch color FED display, and analysis of test results. The test results show that this test system can measure the brightness rangeof0.1－1000cd/m2, the error is less than2%; X direction effective movement distanceof0-815mm; Y direction effective movement distance0-455mm; stepper motormoving distance error is less than3mm.The system is expected to complete the test ofthe various functional areas, but there are still a few questions the drive mechanismconsisting of stepper motor has become the bottleneck in the rate of the system. Sourcesignal of the parameters depends only on DVI, limiting the VGA, AV signal use. Thesequestions need to be further addressed.