US-12622102-B2 - Display device

US12622102B2US 12622102 B2US12622102 B2US 12622102B2US-12622102-B2

Abstract

A display device includes a light-emitting device that may be disposed on an upper planarization layer of a pixel area. A bank insulating layer defining an emission area may be disposed on the upper planarization layer. The upper planarization may include a protruding portion overlapping with the emission area. An edge of the protruding portion may be a curved surface having a constant curvature. The light-emitting device may include a first electrode, a light-emitting layer and a second electrode, which are sequentially stacked on the emission area. The protruding portion may be covered by the first electrode. Thus, in the display device, a decrease in luminance according to a viewing angle may be reduced.

Inventors

Choong Hoon Lee
Yoon Dong CHO
Chang Yoon YANG

Assignees

LG DISPLAY CO., LTD.

Dates

Publication Date: 20260505
Application Date: 20230831
Priority Date: 20230130

Claims (15)

1 . A display device comprising: an upper planarization layer disposed on a device substrate and including a protruding portion in a pixel area; a first electrode disposed on the upper planarization layer and covering the protruding portion; a bank insulating layer disposed on the upper planarization layer and including an opening exposing a portion of the first electrode; a light-emitting layer disposed on the portion of the first electrode exposed by the opening of the bank insulating layer; and a second electrode disposed on the light-emitting layer and extending on the bank insulating layer, wherein an edge of the protruding portion has a curved surface with a constant curvature, and wherein the first electrode includes a curved region overlapping with the edge of the protruding portion.
2 . The display device according to claim 1 , wherein the curved region of the first electrode has a closed loop shape extending along an edge of the opening.
3 . The display device according to claim 1 , further comprising: a lower planarization layer between the device substrate and the upper planarization layer; and an intermediate electrode between the lower planarization layer and the upper planarization layer of the pixel area, wherein the intermediate electrode has a symmetrical shape with respect to a center of the opening.
4 . The display device according to claim 3 , wherein the intermediate electrode has a size larger than the opening of the bank insulating layer.
5 . The display device according to claim 1 , wherein an upper surface of the protruding portion opposite to the device substrate is a flat surface.
6 . The display device according to claim 5 , wherein the opening of the bank insulating layer has a size larger than the upper surface of the protruding portion.
7 . The display device according to claim 5 , wherein the opening of the bank insulating layer overlaps at least a portion of the curved region of the first electrode, and wherein the curved region of the first electrode overlapping with the opening has a constant width.
8 . The display device according to claim 7 , wherein the curved region of the first electrode overlapping with the opening has a closed loop shape extending along the edge of the opening.
9 . A display device comprising: a bank insulating layer disposed on a pixel area of a device substrate, the bank insulating layer defining an emission area; an upper planarization layer disposed between the device substrate and the bank insulating layer, the upper planarization layer including a protruding portion overlapping with the emission area; and a light-emitting device disposed on the upper planarization layer of the emission area, the light-emitting device having a stacked structure of a first electrode, a light-emitting layer and a second electrode, wherein the first electrode extends between the upper planarization layer and the bank insulating layer along a surface of the protruding portion opposite to the device substrate, and wherein an edge of the protruding portion has a convex shape.
10 . The display device according to claim 9 , wherein the edge of the protruding portion having a convex shape has a closed loop shape extending an outer edge of the emission area.
11 . The display device according to claim 9 , further comprising: a lower planarization layer between the device substrate and the upper planarization layer; a pixel driving circuit between the pixel area of the device substrate and the lower planarization layer; an intermediate electrode between the lower planarization layer and the upper planarization layer, the intermediate electrode electrically connected to the pixel driving circuit and the first electrode; and a first signal wiring between the lower planarization layer and the upper planarization layer of the pixel area, the first signal wiring being spaced apart from the intermediate electrode, wherein the first signal wiring is symmetric with the intermediate electrode with respect to a center of the emission area.
12 . The display device according to claim 11 , wherein the first signal wiring extends in a direction, and wherein the intermediate electrode extends parallel to the first signal wiring in the pixel area.
13 . The display device according to claim 11 , wherein the first signal wiring includes a same material as the intermediate electrode.
14 . The display device according to claim 11 , wherein the first signal wiring has a same width as the intermediate electrode.
15 . The display device according to claim 11 , further comprising a second signal wiring between the lower planarization layer and the upper planarization layer, wherein the second signal wiring crosses a center of the emission area, and wherein a distance between the intermediate electrode and the second signal wiring is the same as a distance between the first signal wiring and the second signal wiring.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application claims the priority of Korean Patent Application No. 10-2023-0011942, filed on Jan. 30, 2023, which is hereby incorporated by reference in its entirety. BACKGROUND Field of the Disclosure The present disclosure relates to a display device in which a light-emitting device is disposed in each pixel area. Description of the Background Generally, a display device provides an image to user. For example, the display device may include a plurality of pixel area. Each of the pixel areas may realize a specific color. For example, a light-emitting device may be disposed in each pixel area. The light-emitting device may emit light displaying a specific color. For example, the light-emitting device may have a stacked structure of a first electrode, a light-emitting layer and a second electrode. A pixel driving circuit electrically connected to the light-emitting device may be disposed in each pixel area. The pixel driving circuit of each pixel area may be disposed on a device substrate. The light-emitting device of each pixel area may be disposed on a planarization layer covering the pixel driving circuit of the corresponding pixel area. For example, the first electrode of each light-emitting device may be disposed parallel to an upper surface of the device substrate toward the pixel driving circuit of each pixel area. Thus, in the display device, the luminance of the image provided to a user positioned at an angle may rapidly decrease. Therefore, in the display device, a quality deviation of the image according to a viewing angle may occur. SUMMARY Accordingly, the present disclosure is directed to a display device that substantially obviates one or more problems due to limitations and disadvantages described above. More specifically, the present disclosure is to provide a display device capable of minimizing the quality deviation of the image according to the viewing angle. The present disclosure is also to provide a display device capable of reducing a decrease in the luminance of the image according to the viewing angle. Additional advantages and features of the disclosure will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the disclosure. Other advantages of the disclosure may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings. To achieve these and other advantages and in accordance with the purpose of the present disclosure, as embodied and broadly described herein, a display device includes a device substrate, an upper planarization layer is disposed on the device substrate. The upper planarization layer includes a protruding portion. The protruding portion of the upper planarization is disposed in a pixel area. A first electrode and a bank insulating layer are disposed on the upper planarization layer. The first electrode is disposed on the pixel area. The first electrode covers the protruding portion. The bank insulating layer includes an opening. The opening of the bank insulating layer exposed a portion of the first electrode. A light-emitting layer is disposed on the portion of the first electrode exposed by the opening of the bank insulating layer. A second electrode is disposed on the light-emitting layer. The second electrode extends on the bank insulating layer. An edge of the protruding portion is a curved surface having a constant curvature. The first electrode includes a curved region overlapping with the edge of the protruding portion. The curved region of the first electrode may have a closed loop shape extending along an edge of the opening. A lower planarization layer may be disposed between the device substrate and the upper planarization layer. An intermediate electrode may be disposed between the lower planarization layer and the upper planarization layer of the pixel area. The intermediate electrode may have a symmetrical shape with respect to a center of the opening. The intermediate electrode may have a size larger than the opening of the bank insulating layer. An upper surface of the protruding portion opposite to the device substrate may be a flat surface. The opening of the bank insulating layer may have a size larger than the upper surface of the protruding portion. The opening of the bank insulating layer may overlap at least a portion of the curved region of the first electrode. The curved region of the first electrode overlapping with the opening may have a constant width. The curved region of the first electrode overlapping with the opening may have a closed loop shape extending along the edge of the opening. In another aspect of the present disclosure, a display device includes a device substrate, and a bank insulating layer disposed on a pixel area of the device substrate. The bank ins