Organic light emitting diode display device
An organic light-emitting diode (OLED) display device capable of improving light extraction efficiency and lifetime is disclosed. In the OLED display device, a protective layer having a convex shaped protruding pattern is arranged in a light emitting area at a central portion of a substrate, so that only the light emitting area has a selectively convex protruding shape. Accordingly, in the OLED display device, in a process of forming an organic light emitting layer, the protruding pattern can artificially offset the organic light emitting layer arranged at the central portion of the substrate being sagged, by a protective layer having a convex shaped protruding pattern. As a result, the OLED display device can improve a problem of thickness non-uniformity of the central portion and an edge portion of the substrate due to a sagging phenomenon of the organic light emitting layer.
1. An organic light-emitting diode (OLED) display device, comprising:
a substrate having a light emitting area and a non-light emitting area;
a thin film transistor arranged on the substrate;
a protective layer that covers the light emitting area and the non-light emitting area and has a protruding pattern arranged only in the light emitting area;
an overcoat layer that covers the protective layer;
a first electrode that is arranged on the overcoat layer and is connected to the thin film transistor through a first contact hole to expose a part of the protective layer and the overcoat layer, and overlapped with the protruding pattern;
an organic light emitting layer that is arranged on the first electrode; and
a second electrode that is arranged on the organic light emitting layer,
wherein a top surface of the first electrode has a convex shape, and
wherein a top surface of the organic light emitting layer has a flat shape,
wherein the protective layer is formed of an inorganic layer,
wherein the overcoat layer is formed of an organic layer, and
wherein the protective layer arranged in the non-light emitting area of the substrate has a first thickness, and the protective layer arranged in the light emitting area of the substrate has a second thickness by the protruding pattern, and the second thickness is thicker than the first thickness.
2. The OLED display device of claim 1 , wherein the protruding pattern has an integrated structure with the protective layer.
3. The OLED display device of claim 1 , wherein the protruding pattern has any one shape of a circle, a triangle, a rectangle, a pentagon, a hexagon, and an octagon when viewed in a plane.
4. The OLED display device of claim 1 , wherein the protruding pattern is arranged to correspond to the light emitting area one by one, respectively.
5. The OLED display device of claim 1 , wherein the protruding pattern is arranged in a form separated with at least two or more thereof respectively on the light emitting area.
6. The OLED display device of claim 5 , wherein the separated protruding patterns are arranged spaced apart from each other by a distance of 10 μmor more.
7. The OLED display device of claim 1 , wherein the overcoat layer has a convex shaped protrusion at a position corresponding to the protruding pattern.
8. The OLED display device of claim 7 , wherein the protrusion of the overcoat layer has a thickness of 60 Å or less.
9. The OLED display device of claim 1 , wherein a maximum thickness deviation of the organic light emitting layer arranged at a central portion and an edge portion of the substrate is 10 Å or less.
10. The OLED display device of claim 1 , further comprising a color filter that is arranged in a light emitting area between the protective layer and the overcoat layer, respectively, and is arranged to be overlapped with the organic light emitting layer.
11. The OLED display device of claim 1 , wherein the organic light emitting layer is formed by an ink-jet printing method.
12. The OLED display device of claim 1 , wherein a thickness between the first electrode and the second electrode at a central portion of the organic light emitting layer is smaller than a thickness between the first electrode and the second electrode at an edge portion of the organic light emitting layer.