Method and apparatus for testing TFT array

A testing method for a TFT array substrate using a self-emitting element drive where pixels are arranged in a matrix and a pixel which comprises a drive transistor having a gate formed from a first structural material and a source and a drain formed from a second structural material, and a hold capacitor having a first electrode formed from said first structural material and a second electrode formed from said second structural material, wherein the testing apparatus comprises:

• one or a plurality of power supplies for applying first and second voltages to said pixels;
• a measurement device for measuring the charge in said pixel;
• a controller for applying said second voltage after applying said first voltage to the designated pixel and measuring the charge by said measurement device after applying said second voltage;
• and
• a processor for determining the capacitance of said hold capacitor from said charge and the potential difference between said first voltage and second voltage.