A novel line detection method using magnetic sensor for the optical inspection of electrical short defects on TFT LCD

Abstract

A novel detection method is suggested using magnetic sensor to detect the short-defect line on LCD-TFT panel. With the voltage applied to the TFT panel, current flows along the short-defect line generating magnetic field around it. By scanning the magnetic sensor across the TFT panel, the defect line can be detected. Vision inspection is performed along the detected line to find out the defect point. Three main types of short-defects on TFT panel are tested and their locations are successfully detected by the suggested method.