Transparent display device for detecting defective touch sensor

A transparent display device comprising:

• a substrate provided with a plurality of transmissive areas through which externally incident light passes and a non-transmissive area disposed between the transmissive areas adjacent to each other, the non-transmissive area including a plurality of light emission areas;
• a plurality of touch sensors respectively provided in the plurality of transmissive areas over the substrate, including a touch sensor electrode;
• a plurality of touch lines provided in the non-transmissive area over the substrate and extended in a first direction;
• a plurality of touch bridge lines provided in the non-transmissive area over the substrate and extended in a second direction to be electrically connected to one of the plurality of touch lines;
• a plurality of touch connection portions electrically connecting the plurality of touch bridge lines with the plurality of touch sensors, the plurality of touch connection portions including a high resistance line;
• a plurality of light emitting elements respectively provided in the plurality of light emission areas over the substrate, including an anode electrode, a light emitting layer, and a cathode electrode;
• and
• a first undercut structure provided along an edge of the transmissive area,
• wherein the cathode electrode of the light emitting element is disposed in a same layer as the touch sensor electrode of the touch sensor, and
• wherein the cathode electrode and the touch sensor electrode are separated from each other by the first undercut structure.