OLED Display Low Level Line for Subpixel Crosstalk
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Solution Overview
Problem
In organic light emitting diode (OLED) display devices, the blue subpixel's emitting layer has a shorter lifetime due to its larger area, leading to coupling issues with adjacent subpixels' pixel circuits, causing crosstalk and abnormal luminance displays.
Innovation Solution
The introduction of a low level line between the gate electrode and the anode of adjacent subpixels minimizes coupling, with a storage electrode covering the gate electrode to prevent crosstalk and enable high-speed driving.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If the blue emitting layer area is increased to compensate for its shorter lifetime, then the lifetime balance between subpixels is improved, but coupling between adjacent subpixels increases causing crosstalk
Solution Approach 1:
A low level line is introduced as an intermediary element between the blue subpixel anode and the green subpixel gate electrode. This low level line acts as a mediator that blocks the direct coupling path while maintaining the necessary electrical connections, thereby preventing crosstalk without reducing the blue emitting layer area
Solution Approach 2:
The pixel circuit structure is segmented by dividing the low level line into separate segments for different subpixels. The low level line is divided into a first low level line for the blue subpixel and a second low level line for the green subpixel, which prevents coupling between adjacent subpixels while maintaining independent operation
2Stability of the object's composition
If the blue emitting layer area is increased to match red and green subpixels, then display uniformity is improved, but parasitic capacitance increases causing crosstalk
Solution Approach 1:
The low level line serves as an intermediary that maintains the enlarged blue emitting layer area for display uniformity while blocking the parasitic capacitance path between the blue subpixel anode and green subpixel gate electrode, thereby preventing crosstalk
Solution Approach 2:
The harmful parasitic capacitance coupling path is extracted and isolated by introducing the low level line as a separate structural element that removes the direct electrical coupling between adjacent subpixels
3Object-affected harmful factors
If the low level line is disposed between gate electrode and anode to minimize coupling, then crosstalk is reduced, but device complexity increases
Solution Approach 1:
The low level line is merged with the existing pixel circuit structure and integrated into the standard manufacturing process. The low level line is formed simultaneously with other circuit elements using the same fabrication steps, thereby reducing the actual device complexity despite the additional functional element
Data Source
AI summary
An organic light emitting diode display device includes: a substrate having a plurality of subpixels; a driving transistor in each of the plurality of subpixels on the substrate; a light emitting diode in each of the plurality of subpixels on the driving transistor; and a low level line between the driving transistor and the light emitting diode in each of the plurality of subpixels.