Patent ID: 7122970

Claim:
In a method for testing an OLED substrate comprising: an insulating substrate; a plurality of selection signal lines arranged on the insulating substrate; a plurality of data signal lines arranged so as to cross the selection signal lines; switching elements respectively having a selection terminal and a data terminal at each intersection area of the selection signal lines and the data signal lines; OLED elements where data is provided via the switching elements; and a plurality of common control lines which apply a voltage in accordance with light emitted by the OLED elements, said method comprising; the first step of providing the selection signal lines with a first pulse signal and then providing the common control lines with a second pulse signal in synchronization between the first and the second pulse signals while providing all of the data signal lines with a predetermined level of signal to obtain a first current value passing through a switching element group connected to a selection signal line at each time when providing respective pulse signals; the second step of providing the data signal lines with a third pulse signal sequentially while providing all of the selection lines with the first pulse signal and then providing the common control lines with the second pulse signal in synchronization between the first and the second pulse signals to obtain a second current value passing through a switching element group connected to a data signal line; and the third step of operating a current passing through each switching element including an OLED element from current values for each pulse signal obtained by the first and the second step.