Organic light emitting diode display panel for improving light transmittance and organic light emitting diode display device

1. An organic light emitting diode display panel, comprising:

a first display region comprising a first substrate layer, a thin film transistor layer disposed on the first substrate layer, and a first pixel layer disposed on the thin film transistor layer; and

a second display region disposed adjacent to the first display region, wherein the second display region comprises a second substrate layer and a second pixel layer disposed on the second substrate layer;

wherein the first pixel layer comprises a first anode and a first cathode, the second pixel layer comprises a second anode and a second cathode, wherein a bottom surface of the first anode is coplanar with a bottom surface of the second cathode, the thin film transistor layer comprises a thin film transistor, and the first anode and the second anode are electrically connected to the thin film transistor disposed on the first substrate layer of the first display region, the thin film transistor layer is not disposed in the second display region, a pixel unit in the first pixel layer and a pixel unit in the second pixel layer respectively correspond to the thin film transistor disposed on the first substrate layer of the first display region for the thin film transistor disposed in the first display region to control the display function of the second display region;

wherein a second buffer layer is disposed between the first substrate layer and the thin film transistor layer, and a first planarization layer is disposed between the thin film transistor layer and the first pixel layer;

wherein a second planarization layer is disposed between the second substrate layer and the second pixel layer;

wherein the thin film transistor layer further comprises: an active layer, a first insulating layer disposed on the active layer, a first metal layer disposed on the first insulating layer, a second insulating layer disposed on the first metal layer, a second metal layer disposed on the second insulating layer, a third insulating layer disposed on the second metal layer, and an electrode layer disposed on the third insulating layer;

a first through hole is disposed penetrating through the first insulating layer, the second insulating layer, and the third insulating layer, and wherein the electrode layer is electrically connected to the active layer through the first through hole;

a second through hole is disposed penetrating through the first planarization layer, and the first anode is electrically connected to the electrode layer through the second through hole;

wherein a metal trace is disposed between a second flexible layer of the second substrate layer and the second planarization layer, the metal trace is disposed at a junction between the second planarization layer and the thin film transistor layer, the metal trace is electrically connected to the electrode layer and the metal trace is electrically connected to a drain of the thin film transistor;

wherein a third through hole is disposed penetrating through the second planarization layer, and the second anode is electrically connected to the metal trace through the third through hole; and

wherein a bonding interface of the first display region and the second display region is stepped, and the metal trace is electrically connected to the electrode layer along the stepped bonding interface.

2. The organic light emitting diode display panel according to claim 1 , wherein the first substrate layer and the second substrate layer are integrated into an integrated structure as a substrate layer; and

wherein the substrate layer comprises a first flexible layer, a first buffer layer disposed on the first flexible layer, and a second flexible layer disposed on the first buffer layer.

3. The organic light emitting diode display panel according to claim 1 , wherein a thickness of the second display region is less than a thickness of the first display region.

4. The organic light emitting diode display panel according to claim 1 , wherein a thickness of the second planarization layer is greater than or equal to a thickness of the first planarization layer.

5. The organic light emitting diode display panel according to claim 1 , wherein the first pixel layer further comprises a first pixel defining layer disposed on the first anode, and the first cathode layer disposed on the first pixel defining layer.

6. The organic light emitting diode display panel according to claim 1 , wherein the second pixel layer further comprises a second pixel defining layer disposed on the second anode, and the second cathode layer disposed on the second pixel defining layer.

7. The organic light emitting diode display panel according to claim 1 , wherein the organic light emitting diode display panel further comprises a bending region, and the bending region is disposed outside a display region composed of the first display region and the second display region.

8. The organic light emitting diode display panel according to claim 7 , wherein the bending region comprises a third substrate layer and a metal wiring layer disposed on the third substrate layer.

9. The organic light emitting diode display panel according to claim 8 , wherein a transition layer is disposed between the third substrate layer and the metal wiring layer, and the transition layer is made of a flexible material for bending the bending region to a back side of the display panel.

10. The organic light emitting diode display panel according to claim 7 , wherein a thin film encapsulation layer is disposed on the first display region, the second display region, and the bending region.

11. An organic light emitting diode display device, comprising: the organic light emitting diode display panel according to claim 1 , and a photosensitive element disposed on a back surface of the second display region.

12. The organic light emitting diode display device according to claim 11 , wherein the second anode is electrically connected to the thin film transistor through the metal trace disposed in the second display region.