WO-2026091066-A1 - LIGHT SOURCE AND METHOD OF OPERATING LIGHT SOURCE

WO2026091066A1WO 2026091066 A1WO2026091066 A1WO 2026091066A1WO-2026091066-A1

Abstract

A light source is provided. The light source includes a first electrode layer; a first light emitting layer on the first electrode layer; a second electrode layer on a side of the first light emitting layer away from the first electrode layer; a second light emitting layer on a side of the second electrode layer away from the first light emitting layer; and a third electrode layer on a side of the second light emitting layer away from the second electrode layer. When a current in the first light emitting layer is greater than a current in the second light emitting layer: a current in the first electrode layer is along a direction from a periphery to a center of the first electrode layer; a current in the second electrode layer is along a direction from a center to a periphery of the second electrode layer.

Inventors

LIU, Xiuting
WU, TONG
YU, Xinye
QU, Xue
YUAN, Can
ZHANG, Xiangze
WANG, NINGNING
JIA, WENBIN
WANG, Jiali
YUAN, Yuling
ZHANG, YONGFENG
BU, Qianqian

Assignees

BOE TECHNOLOGY GROUP CO., LTD.
HEFEI XINSHENG OPTOELECTRONICS TECHNOLOGY CO., LTD.

Dates

Publication Date: 20260507
Application Date: 20241101

Claims (20)

A light source, comprising: a first electrode layer; a first light emitting layer on the first electrode layer; a second electrode layer on a side of the first light emitting layer away from the first electrode layer; a second light emitting layer on a side of the second electrode layer away from the first light emitting layer; and a third electrode layer on a side of the second light emitting layer away from the second electrode layer; wherein, when a current in the first light emitting layer is greater than a current in the second light emitting layer: a current in the first electrode layer is along a direction from a periphery to a center of the first electrode layer; a current in the second electrode layer is along a direction from a center to a periphery of the second electrode layer; and a current in the third electrode layer is along a direction from a center to a periphery of the third electrode layer; wherein, when a current in the second light emitting layer is greater than a current in the first light emitting layer: a current in the first electrode layer is along a direction from a periphery to a center of the first electrode layer; a current in the second electrode layer is along a direction from a periphery to a center of the second electrode layer; and a current in the third electrode layer is along a direction from a center to a periphery of the third electrode layer.
The light source of claim 1, wherein a current in the first light emitting layer is along a direction from the first electrode layer to the third electrode layer; and a current in the second light emitting layer is along a direction from the first electrode layer to the third electrode layer.
The light source of claim 1, wherein the first electrode layer comprises a metal oxide material, the second electrode layer comprises a metal oxide material, and the third electrode layer comprises a metallic material.
The light source of claim 1, further comprising bonding regions of the first electrode layer, the second electrode layer, and the third electrode layer in a peripheral region of the light source; wherein first bonding regions of the first electrode layer are on a first side and a second side of the light source, respectively; second bonding regions of the second electrode layer are on a third side and a fourth side of the light source, respectively; third bonding regions of the third electrode layer are on a first side and a second side of the light source, respectively; the first side and the second side are opposite to each other; the third side and the fourth side are opposite to each other; the third side connects the first side and the second side; and the fourth side connects the first side and the second side.
The light source of claim 4, wherein, on the first side, the light source includes at least one of the first bonding regions and at least two of the third bonding regions; the at least one of the first bonding regions spaces apart the at least two of the third bonding regions; on the first side, one of the third bonding regions, one of the first bonding regions, and one of the third bonding regions are sequentially arranged; on the second side, the light source includes at least one of the first bonding regions and at least two of the third bonding regions; the at least one of the first bonding regions spaces apart the at least two of the third bonding regions; and on the second side, one of the third bonding regions, one of the first bonding regions, and one of the third bonding regions are sequentially arranged.
The light source of claim 4, wherein at least one of the first electrode layer, the second electrode layer, and the third electrode layer are an electrode layer of metal oxide material; and at least another of the first electrode layer, the second electrode layer, and the third electrode layer are an electrode layer of metallic material; wherein, along a periphery of the light source, a length of one or more bonding regions of metallic material is less than a length of one or more bonding regions of metal oxide material.
The light source of claim 1, wherein, when a current in the first light emitting layer is greater than a current in the second light emitting layer: in a central region of the first light emitting layer, a voltage difference between the first electrode layer and the second electrode layer is the smallest, and the voltage drop in this region is also the smallest.
The light source of claim 1, wherein, when a current in the first light emitting layer is greater than a current in the second light emitting layer: a difference between a maximum and a minimum voltage drop across the first light emitting layer equals an IR drop from first bonding regions of the first electrode layer to a central region of the first electrode layer plus an IR drop from second bonding regions of the second electrode layer to a central region of the second electrode layer.
The light source of claim 1, wherein, when a current in the first light emitting layer is greater than a current in the second light emitting layer: one or more regions of the second light emitting layer most proximal to the second bonding regions are brightest regions of the second light emitting layer when the second light emitting layer is configured to emit light; in the one or more regions of the second light emitting layer most proximal to the second bonding regions, a voltage difference between the second electrode layer and the third electrode layer is the greatest; one or more regions of the second light emitting layer most distal to the second bonding regions are the dimmest regions of the second light emitting layer when the second light emitting layer is configured to emit light; and in the one or more regions of the second light emitting layer most distal to the second bonding regions, a voltage difference between the second electrode layer and the third electrode layer is the smallest.
The light source of claim 1, wherein, when a current in the first light emitting layer is greater than a current in the second light emitting layer: a difference between a maximum and a minimum voltage drop across the second light emitting layer equals an IR drop from second bonding regions of the second electrode layer to a central region of the second electrode layer plus an IR drop from third bonding regions of the third electrode layer to a central region of the third electrode layer.
The light source of claim 1, wherein, when a current in the second light emitting layer is greater than a current in the first light emitting layer, and an IR drop from first bonding regions of the first electrode layer to a central region of the first electrode layer minus an IR drop from second bonding regions of the second electrode layer to a central region of the second electrode layer is a positive value: a central region of the first light emitting layer is the dimmest region of the first light emitting layer when the first light emitting layer is configured to emit light; and in the central region of the first light emitting layer, a voltage difference between the first electrode layer and the second electrode layer is the smallest, and the voltage drop in the central region is also the smallest.
The light source of claim 1, wherein, when a current in the second light emitting layer is greater than a current in the first light emitting layer, and an IR drop from first bonding regions of the first electrode layer to a central region of the first electrode layer minus an IR drop from second bonding regions of the second electrode layer to a central region of the second electrode layer is a negative value: a central region of the first light emitting layer is the brightest region of the first light emitting layer when the first light emitting layer is configured to emit light; and in the central region of the first light emitting layer, a voltage difference between the first electrode layer and the second electrode layer is the greatest, and the voltage drop in this region is also the greatest.
The light source of claim 1, wherein, when a current in the second light emitting layer is greater than a current in the first light emitting layer: a central region of the second light emitting layer is the dimmest region of the second light emitting layer when the second light emitting layer is configured to emit light; and in the central region of the second light emitting layer, a voltage difference between the second electrode layer and the third electrode layer is the smallest.
The light source of claim 1, wherein, when a current in the second light emitting layer is greater than a current in the first light emitting layer: a difference between a maximum and a minimum voltage drop across the second light emitting layer equals an IR drop from second bonding regions of the second electrode layer to a central region of the second electrode layer plus an IR drop from third bonding regions of the third electrode layer to a central region of the third electrode layer.
The light source of claim 1, further comprising bonding regions of the first electrode layer, the second electrode layer, and the third electrode layer in a peripheral region of the light source; wherein first bonding regions of the first electrode layer are on a first side and a second side of the light source, respectively; second bonding regions of the second electrode layer are on a third side and a fourth side of the light source, respectively; third bonding regions of the third electrode layer are on a fifth side and a sixth side of the light source, respectively; the first side and the second side are opposite to each other; the third side and the fourth side are opposite to each other; the fifth side and the sixth side are opposite to each other; the fourth side connects the first side and the sixth side; the sixth side connects the fourth side and the second side; the second side connects the sixth side and the third side; the third side connects the second side and the fifth side; and the fifth side connects the third side and the first side.
The light source of claim 15, wherein, on the first side, the light source includes at least one of the first bonding regions; on the second side, the light source includes at least one of the first bonding regions; on the third side, the light source includes at least one of the second bonding regions; on the fourth side, the light source includes at least one of the second bonding regions; on the fifth side, the light source includes at least one of the third bonding regions; and on the sixth side, the light source includes at least one of the third bonding regions.
The light source of claim 1, wherein a maximum voltage drop for the first electrode layer is K1X; a maximum voltage drop for the third electrode layer is K2Y; a maximum voltage drop for the second electrode layer is |K3X-K4Y| ; K1 is a proportionality constant associated with the first electrode layer; K2 is a proportionality constant associated with the third electrode layer; K3 and K4 are proportionality constants associated with the second electrode layer; X stands for brightness of the first light emitting layer; and Y stands for brightness of the second light emitting layer.
The light source of claim 17, wherein, when a current density of the first light emitting layer is greater than a current density of the second light emitting layer: a voltage difference between brightest and dimmest areas of the first light emitting layer is K1X + |K3X-K4Y| ; and a voltage difference between the brightest and dimmest areas of the second light emitting layer is |K3X-K4Y| + K2Y.
The light source of claim 17, wherein, when a current density of the second light emitting layer is greater than a current density of the first light emitting layer: a voltage difference between brightest and dimmest areas of the first light emitting layer is K1X - |K3X-K4Y| ; and a voltage difference between brightest and dimmest areas of the second light emitting layer is |K3X -K4Y| + K2Y.
A method of operating a light source; wherein the light source comprises: a first electrode layer; a first light emitting layer on the first electrode layer; a second electrode layer on a side of the first light emitting layer away from the first electrode layer; a second light emitting layer on a side of the second electrode layer away from the first light emitting layer; and a third electrode layer on a side of the second light emitting layer away from the second electrode layer; wherein the method comprises operating the light source in a first mode; wherein, in the first mode, the first light emitting layer is configured to emit light, and the second light emitting layer is configured not to emit light; a difference between a maximum and a minimum voltage drop across the first light emitting layer is smaller than a first threshold value; the difference between the maximum and the minimum voltage drop across the first light emitting layer equals an IR drop from first bonding regions of the first electrode layer to a central region of the first electrode layer plus an IR drop from second bonding regions of the second electrode layer to a central region of the second electrode layer; and the first threshold value is a value at which a brightness uniformity of the light source is greater than 95%.

Description

LIGHT SOURCE AND METHOD OF OPERATING LIGHT SOURCE TECHNICAL FIELD The present invention relates to display technology, more particularly, to a light source and a method of operating a light source. BACKGROUND Display technologies have evolved significantly over the years, with advancements in materials and design enabling more efficient and versatile light-emitting devices. Organic light-emitting diodes (OLEDs) are increasingly used in various applications, including lighting and display panels, due to their ability to provide high-quality light with enhanced color rendering and energy efficiency. SUMMARY In one aspect, the present disclosure provides a light source, comprising a first electrode layer; a first light emitting layer on the first electrode layer; a second electrode layer on a side of the first light emitting layer away from the first electrode layer; a second light emitting layer on a side of the second electrode layer away from the first light emitting layer; and a third electrode layer on a side of the second light emitting layer away from the second electrode layer; wherein, when a current in the first light emitting layer is greater than a current in the second light emitting layer: a current in the first electrode layer is along a direction from a periphery to a center of the first electrode layer; a current in the second electrode layer is along a direction from a center to a periphery of the second electrode layer; and a current in the third electrode layer is along a direction from a center to a periphery of the third electrode layer; wherein, when a current in the second light emitting layer is greater than a current in the first light emitting layer: a current in the first electrode layer is along a direction from a periphery to a center of the first electrode layer; a current in the second electrode layer is along a direction from a periphery to a center of the second electrode layer; and a current in the third electrode layer is along a direction from a center to a periphery of the third electrode layer. Optionally, wherein a current in the first light emitting layer is along a direction from the first electrode layer to the third electrode layer; and a current in the second light emitting layer is along a direction from the first electrode layer to the third electrode layer. Optionally, the first electrode layer comprises a metal oxide material, the second electrode layer comprises a metal oxide material, and the third electrode layer comprises a metallic material. Optionally, the light source further comprises bonding regions of the first electrode layer, the second electrode layer, and the third electrode layer in a peripheral region of the light source; wherein first bonding regions of the first electrode layer are on a first side and a second side of the light source, respectively; second bonding regions of the second electrode layer are on a third side and a fourth side of the light source, respectively; third bonding regions of the third electrode layer are on a first side and a second side of the light source, respectively; the first side and the second side are opposite to each other; the third side and the fourth side are opposite to each other; the third side connects the first side and the second side; and the fourth side connects the first side and the second side. Optionally, on the first side, the light source includes at least one of the first bonding regions and at least two of the third bonding regions; the at least one of the first bonding regions spaces apart the at least two of the third bonding regions; on the first side, one of the third bonding regions, one of the first bonding regions, and one of the third bonding regions are sequentially arranged; on the second side, the light source includes at least one of the first bonding regions and at least two of the third bonding regions; the at least one of the first bonding regions spaces apart the at least two of the third bonding regions; and on the second side, one of the third bonding regions, one of the first bonding regions, and one of the third bonding regions are sequentially arranged. Optionally, at least one of the first electrode layer, the second electrode layer, and the third electrode layer are an electrode layer of metal oxide material; and at least another of the first electrode layer, the second electrode layer, and the third electrode layer are an electrode layer of metallic material; wherein, along a periphery of the light source, a length of one or more bonding regions of metallic material is less than a length of one or more bonding regions of metal oxide material. Optionally, when a current in the first light emitting layer is greater than a current in the second light emitting layer: in a central region of the first light emitting layer, a voltage difference between the first electrode layer and the second electrode layer is the smallest, and the voltage drop in this region is als