Organic light emitting display device

1. An organic light emitting display device comprising:

a substrate;

a plurality of unit pixels on the substrate, each unit pixel including a first region that emits light and a second region that transmits external light, and wherein, with respect to two adjacent pixels of the plurality of unit pixels, the first region and the second region in one unit pixel are symmetrical with the first region and the second region in another adjacent unit pixel, and the second regions are connected to each other;

a plurality of thin film transistors (TFTs) disposed in the first region of each unit pixel;

a plurality of first electrodes disposed in the first region of each unit pixel, each first electrode being electrically connected to one of the TFTs;

a second electrode facing the plurality of first electrodes and commonly disposed in the unit pixels; and

an organic layer interposed between the first electrodes and the second electrode, and including an emissive layer.

2. The organic light emitting display device as claimed in claim 1 , wherein, with respect to four adjacent unit pixels of the plurality of unit pixels, the first region and the second region in one unit pixel are symmetrical with the first region and the second region in another adjacent unit pixel.

3. The organic light emitting display device as claimed in claim 1 , wherein, with respect to a 2×2 array of four unit pixels of the plurality of unit pixels, the first region and the second region in a unit pixel are symmetrical with the first region and the second region in an adjacent unit pixel, and the second regions of the four unit pixels are connected to each other.

4. The organic light emitting display device as claimed in claim 1 , wherein the second electrode includes a light-reflective material.

5. The organic light emitting display device as claimed in claim 4 , wherein each of the first electrodes includes a light-transmissive material.

6. The organic light emitting display device as claimed in claim 1 , wherein the second electrode includes a transmissive window that is formed by removing a portion of the second electrode corresponding to the second region.

7. The organic light emitting display device as claimed in claim 6 , wherein the transmissive window of one unit pixel is connected to the transmissive window of another adjacent unit pixel.

8. The organic light emitting display device as claimed in claim 6 , wherein, with respect to four adjacent unit pixels of the plurality of unit pixels, the transmissive window of one unit pixel is connected to the transmissive window of another adjacent pixel.

9. The organic light emitting display device as claimed in claim 1 , wherein each of the TFTs and a corresponding one of the first electrodes are in an overlapping relationship with each other.

10. The organic light emitting display device as claimed in claim 1 , wherein:

the first region of each unit pixel includes an emissive region and a circuit region,

each of the TFTs is disposed in the circuit region of a corresponding unit pixel, and

each of the first electrodes is disposed in the emissive region of a corresponding unit pixel.

11. The organic light emitting display device as claimed in claim 10 , further comprising a wiring portion electrically connecting the emissive region and the circuit region, wherein the wiring portion is disposed outside an edge portion of the second region.

12. The organic light emitting display device as claimed in claim 1 , wherein the emissive region and the circuit region of each unit pixel are adjacent to each other.

13. The organic light emitting display device as claimed in claim 1 , further comprising:

a passivation layer covering the TFTs; and

a pixel definition layer formed on the passivation layer and covering edge portions of the first electrodes.

14. The organic light emitting display device as claimed in claim 13 , wherein the passivation layer includes an opening with respect to each unit pixel, the opening corresponding to the second region.

15. The organic light emitting display device as claimed in claim 1 , further comprising a buffer layer formed on the substrate.

16. The organic light emitting display device as claimed in claim 15 , wherein the buffer layer includes an opening corresponding to the second region.

17. An organic light emitting display device, comprising:

a substrate;

a plurality of unit pixels on the substrate, each unit pixel including a first region that emits light and a second region that transmits external light, and wherein, with respect to two adjacent pixels of the plurality of unit pixels, the first region and the second region in one unit pixel are symmetrical with the first region and the second region in another adjacent unit pixel, and the second regions are connected to each other;

a plurality of thin film transistors (TFTs) disposed in the first region of each unit pixel;

a plurality of first electrodes disposed in the first region of each unit pixel, each first electrode being electrically connected to one of the TFTs;

a second electrode facing the plurality of first electrodes and commonly disposed in the unit pixels;

an organic layer interposed between the first electrodes and the second electrode, and including an emissive layer;

a pixel definition layer covering edge portions of the first electrodes and including an opening with respect to each unit pixel, the opening corresponding to the second region.

18. The organic light emitting display device as claimed in claim 17 , wherein the opening of the pixel definition layer of one unit pixel is connected to the opening of the pixel definition layer of another adjacent unit pixel.

19. The organic light emitting display device as claimed in claim 17 , wherein, with respect to four adjacent unit pixels of the plurality of unit pixels, the opening of the pixel definition layer of one unit pixel is connected to the opening of the pixel definition layer of another adjacent unit pixel.