Shielding Electrode for Emissive Display Coupling Reduction
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Solution Overview
Problem
Emissive display devices with n-type transistors face deterioration in display quality due to coupling with data lines, leading to issues such as horizontal line defects and variations in voltage, which affect the channel characteristics of driving transistors.
Innovation Solution
Incorporating a shielding electrode positioned between the data line and the overlapping electrode voltage line, which crosses the data line in a plan view and is located between the data line and the initialization voltage line in a cross-sectional view, to shield coupling effects and maintain stable voltage levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If voltage lines cross the data line in a plan view to supply voltage to the driving transistor, then the device complexity is reduced and manufacturing is simplified, but coupling capacitance between the data line and voltage lines increases causing horizontal line defects and voltage variations
Solution Approach 1:
A shielding electrode is introduced as an intermediary element positioned between the data line and the overlapping electrode voltage line. This shielding electrode acts as a mediator that blocks the direct capacitive coupling between the two lines, thereby reducing the harmful coupling capacitance while allowing the voltage line to maintain its overlapping configuration for simplified manufacturing
Solution Approach 2:
The harmful coupling capacitance is extracted and isolated by introducing the shielding electrode. The shielding electrode creates a separate capacitive path that prevents the direct interaction between the data line and voltage line, effectively removing the harmful coupling effect from the original configuration
2Area of stationary object
If the overlapping electrode voltage line is positioned close to the data line for compact design, then the area is reduced, but display quality deteriorates due to coupling effects causing horizontal line defects
Solution Approach 1:
The shielding electrode serves as a protective intermediary that enables the overlapping electrode voltage line to be positioned close to the data line for compact pixel design while preventing harmful coupling effects. This mediator allows compact arrangement without sacrificing display quality
3Device complexity
If no shielding electrode is used to simplify the structure, then the device complexity is reduced, but voltage stability deteriorates due to coupling capacitance causing horizontal line defects
Solution Approach 1:
The shielding electrode acts as a necessary intermediary to maintain voltage stability. By positioning the shielding electrode between the data line and overlapping electrode voltage line, it blocks capacitive coupling that would otherwise cause voltage variations and horizontal line defects, thereby ensuring stable voltage supply to the driving transistor
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 significantly reduces coupling capacitance between the data line and voltage lines, preventing horizontal line defects and maintaining display quality by ensuring consistent voltage across the driving transistor, thereby enhancing the operational stability of the emissive display device.
Implementation Method 1
a shielding electrode positioned at an intersection of the data line and the overlapping electrode voltage line and positioned between the data line and the overlapping electrode voltage line in a cross-sectional view
Data Source
AI summary
An emissive display device includes: a light emitting diode; an n-type driving transistor comprising a first driving gate electrode, a first electrode receiving a driving voltage, a second electrode transferring an output current to the anode, and a second driving gate electrode; a second transistor connected to a data line; a third transistor configured to connect the first electrode and the first driving gate electrode of the driving transistor; a storage capacitor comprising a first storage electrode and a second storage electrode connected to the first driving gate electrode; a ninth transistor transferring an overlapping electrode voltage to the second driving gate electrode; an overlapping electrode voltage line crossing the data line and receiving the overlapping electrode voltage; and a shielding electrode at an intersection of the data line and the overlapping electrode voltage line and between the data line and the overlapping electrode voltage line.