US Patent 7123044 Testing method, semiconductor device, and display apparatus

A method for testing a semiconductor substrate forming a liquid crystal display device, which method enables a potential change corresponding to a defective condition of pixel cell driving circuits to be detected accurately even when a ratio of pixel capacitance to wiring capacitance is lowered with decrease in size or increase in definition of the liquid crystal display device. The method includes: a charge retaining step for making pixel capacitances connected to a plurality of pixel switches selected from all pixel switches connected to one data line retain charge; and a detecting step for simultaneously detecting the charge retained in a plurality of the pixel capacitances in the charge retaining step from the one data line.