Display device

A display device comprising:

• a substrate comprising:
• a main area having a display area in which emission areas are arranged and a non-display area around the display area;
• and
• a sub-area protruding from a side of the main area;
• a circuit layer on the substrate and comprising pixel drivers respectively corresponding to the emission areas and data lines configured to transmit data signals to the pixel drivers;
• a light emitting element layer on the circuit layer and comprising light emitting elements corresponding to the emission areas, respectively;
• and
• a display driving circuit on the sub-area of the substrate and configured to supply data driving signals corresponding to the data lines,
• wherein the circuit layer further comprises:
• demux circuit units in a demux area of the non-display area in a first direction and electrically connected between the data lines and the display driving circuit;
• circuit output lines electrically connected to the display driving circuit and extending to the demux area;
• test signal supply lines in the non-display area and respectively configured to transmit test signals for testing a lighting state of the light emitting elements;
• and
• test pad connection lines respectively electrically connected to test signal pads in the sub-area and extending to the non-display area, and
• wherein the demux area comprises:
• a demux middle area in a middle in the first direction;
• a first demux side area adjacent to an edge of the substrate in the first direction;
• and
• a second demux side area between the demux middle area and the first demux side area in the first direction,
• wherein
• a first demux circuit unit in the first demux side area among the demux circuit units is electrically connected to a first circuit output line among the circuit output lines through an input connection line in the non-display area and an input detour line in the display area,
• the test signal supply lines are electrically connected to the test pad connection lines through test line connection contact holes, respectively, and
• the test line connection contact holes are in a test connection area which is a part of the first demux side area.