OLED Lighting Apparatus Cathode Segmentation for Moisture Barrier
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Solution Overview
Problem
Organic light emitting diode (OLED) lighting apparatuses are vulnerable to intercellular moisture permeation and dark spot transitions due to the organic layer, which affects their reliability and optical efficiency, especially when the cathode is patterned or exposed to moisture.
Innovation Solution
The use of a primary cathode and a secondary cathode, where the organic layer is limitedly disposed in the emission zone by the primary cathode and the secondary cathode, with the secondary cathode being laterally connected to the primary cathode, and an encapsulating unit is employed to block moisture permeation and enhance optical efficiency by guiding light emitted from the organic layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the organic layer is formed on the entire surface of the substrate, then the lighting apparatus can be manufactured with simpler processes, but the apparatus becomes vulnerable to intercellular moisture permeation and dark spot transitions
Solution Approach 1:
The organic layer is segmented into emission zones and non-emission zones, with the non-emission zones serving as barrier regions that block moisture permeation paths. This segmentation allows the organic layer to provide both manufacturing simplicity and moisture resistance by creating discrete functional regions rather than a continuous vulnerable layer.
Solution Approach 2:
The patent introduces an encapsulating layer as an intermediary element that covers the organic layer and provides additional moisture barrier protection. This encapsulating layer acts as a mediator between the organic layer and the external environment, preventing moisture from reaching the organic layer through foreign matter penetration paths.
2Ease of manufacture
If the organic layer is patterned on the entire surface of the substrate, then the manufacturing process is simpler, but foreign matter generated during cathode patterning can penetrate through the organic layer causing intercellular moisture permeation
Solution Approach 1:
The organic layer is divided into emission zones where light is generated and non-emission zones that serve as protective barriers. This segmentation prevents foreign matter from creating continuous penetration paths through the organic layer, as the non-emission zones act as discontinuous barrier regions that block moisture transport.
Solution Approach 2:
The patent employs thin film encapsulation layers that conformally cover the organic layer structure. These flexible thin films provide effective moisture barrier protection while accommodating the patterned structure of the organic layer, preventing foreign matter from reaching the organic layer through the patterned regions.
3Device complexity
If a traditional single cathode structure is used, then the device structure is simpler, but the optical efficiency is reduced due to light loss in non-emission zones
Solution Approach 1:
The cathode is segmented into a primary cathode in the emission zone and a secondary cathode in the non-emission zone. This segmentation allows the primary cathode to be optimized for light emission efficiency while the secondary cathode manages electrical connections and provides additional optical management in the non-emission regions, reducing overall light loss.
Solution Approach 2:
The patent introduces a lateral connection dimension between the primary and secondary cathodes, extending the cathode structure from a simple planar configuration to a multi-dimensional arrangement. This dimensional extension allows for improved light extraction and reduced optical losses by managing light paths in multiple spatial dimensions.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration effectively blocks intercellular moisture permeation and dark spot transitions, improving the reliability and optical efficiency of the OLED lighting apparatus, and can be applied to both single-side and double-side light emitting transparent lighting systems.
Implementation Method 1
a lighting apparatus using an organic light emitting diode includes: an anode disposed in an emission area of a substrate; an insulating layer disposed on the anode of a non-emission zone of the emission area; an organic layer and a primary cathode disposed on an anode of an emission zone of the emission area
Data Source
AI summary
A lighting apparatus using an organic light emitting diode comprises a first anode and a second anode respectively disposed in an emission zone and a non-emission zone of an emission area defined at a substrate; a first insulating layer disposed on the second anode; an organic layer and a primary cathode disposed on the first anode; a secondary cathode disposed on the insulating layer and laterally connected to the primary cathode; and an encapsulating material disposed above the substrate, wherein the organic layer is disposed only between the primary cathode and the secondary cathode in the emission zone.