The Method Of Workpiece's Auto-correction In The System Of PDP Electrode On-off Detection

With the development of the PDP display technology, its manufacturing process becomes more and more sophisticated, while the probability of PDP electrode defects increases. In the system of PDP on-off detection, the automatic correction of the workpiece glass substrate has become an important research topic. In order to ensure the accuracy of test results, we need to measure and judge the placement of the workpiece, and correct it to the right position for detection before the detection. In the production line, errors and mistakes will occur due to fatigue, differences between individuals when measured, judged and corrected in artificial. But the machine can continue tirelessly and steadily , so we use the method of auto-correction.This paper firstly introduces the PDP electrode, and proposes test requirements with the detection method of probe-contact voltage as an example, then determines the PDP electrode'maximum position error.Then describes the calibration process before the on-off detection according to the PDP electrode test platform. The PDP electrode test platform is a two-dimensional X-Y motion platform, its position column can complete the first location. According to the coordinates of the crosses in the four corners of the PDP electrode, we can determine whether it is needed to do the second location. To extract the coordinates of the crosses, we use the camera to acquire the image, then process the image and extract the coordinate with a computer.Then compare the coordinate extracted with the reference designed, and the species of the corrected path can be determined. After analyzing the basic principles of the by-point comparison algorithm, the minimum deviation algorithm, the digital DDA algorithm introduced, an improved algorithm based on the by-point comparison algorithm is proposed, and the circular path is planed.Finally, under the rules of the motor when correcting the test platform, the fitting simulation of the X-Y direction's path planning can be got using the improved circular interpolation algorithm. The fitting path diagram is just consistent with the circular interpolation path diagram. Analyzing with an example, the error shows that the fitting results meet the system designing requirement.