Display panel and testing method thereof, display device

A testing method of a display panel, wherein the display panel comprises:

• a plurality of gate lines, a plurality of data lines, a plurality of test signal lines, and a plurality of pixel units, wherein the plurality of pixel units are provided in regions arranged in rows and columns formed by intercrossing of the plurality of gate lines and the plurality of data lines, and each of the plurality of pixel units comprises an organic light emitting diode (OLED), wherein
• an even number of adjacent data lines among the plurality of data lines are grouped as a data line group such that the plurality of data lines are grouped as a plurality of data line groups, one test signal line is provided at a middle position of the data line group such that the numbers of data lines at both sides of the test signal line are same,
• the plurality of test signal lines are provided at a different layer of the display panel than the plurality of data lines, and the plurality of data line groups are in one-to-one correspondence with the plurality of test signal lines, each of the plurality of test signal lines comprises one first extending part and a plurality of second extending parts coupled to the first extending part;
• the first extending part extends along a first direction parallel to the plurality of data lines;
• each of the second extending parts extends symmetrically at both sides of the first extending part along a second direction perpendicular to the first direction, to electrically connect to anodes of OLEDs of a row of pixel units corresponding to the data line group, and an orthographic projection of each of the second extending parts on a layer where the plurality of data lines are located has overlapping regions that overlap with each data line in the data line group,
• the testing method comprises a plurality of test cycles, a test time period of each of the test cycles comprises a plurality of test stages, the plurality of test stages test, in one-to-one correspondence, respective ones of pixel units corresponding to data lines in the data line group,
• wherein, in each test stage, an anode of an OLED in a pixel unit to be tested is kept being electrically coupled to a corresponding test signal line, data lines in the data line group except for both a data line corresponding to the pixel unit to be tested and an offset data line are kept being supplied with zero voltage, wherein the offset data line is a data line in the data line group used for offsetting a voltage on the data line corresponding to the pixel unit to be tested, each of the test stages comprises:
• a first initialization sub-stage:
• supplying the data line corresponding to the pixel unit to be tested and the corresponding test signal line with zero voltage to initialize the pixel unit to be tested, while supplying the offset data line with a test voltage;
• a second initialization sub-stage:
• supplying the data line corresponding to the pixel unit to be tested with the test voltage and keeping the corresponding test signal line being supplied with zero voltage while storing electric energy, while supplying the offset data line with zero voltage;
• a test sub-stage:
• cutting off connection between the pixel unit to be tested and the corresponding data line, stopping the corresponding test signal line being supplied with zero voltage, and testing a voltage at the anode of the OLED in the pixel unit to be tested by the test signal line coupled to the anode of the OLED of the pixel unit to be tested using the stored electric energy.