Light-emitting display device auxiliary electrode parasitic capacitance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Transistors with oxide semiconductors in light-emitting display devices experience significant threshold voltage changes due to parasitic capacitance, leading to degraded display quality, particularly evident in low grayscale images with staining issues.
Innovation Solution
The light-emitting display device incorporates a unique configuration with an auxiliary electrode positioned between the data line and the gate electrode, reducing parasitic capacitance by minimizing coupling between these elements, and includes a shielding electrode connected to the auxiliary driving voltage line to maintain uniform voltage transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a transistor including an oxide semiconductor is used, then the display device achieves low power consumption and high luminance, but the transistor experiences significant threshold voltage change due to parasitic capacitance, degrading display quality
Solution Approach 1:
A shielding electrode is introduced as an intermediary element between the data line and the gate electrode of the transistor. This shielding electrode, positioned at the same layer as the lower electrode or first semiconductor, acts as a mediator to reduce the parasitic capacitance coupling between the data line and gate electrode, thereby stabilizing the threshold voltage while maintaining the low power consumption characteristics of oxide semiconductor transistors
2Device complexity
If the data line is positioned close to the gate electrode for compact design, then the device complexity is reduced, but the parasitic capacitance between the data line and gate electrode increases, causing staining at low grayscales
Solution Approach 1:
The shielding electrode serves as a protective intermediary placed between the data line and gate electrode. Even when the data line is positioned close to the gate electrode for compact layout, the shielding electrode blocks the harmful electromagnetic coupling, preventing parasitic capacitance from causing display defects such as grayscale staining
Solution Approach 2:
The shielding electrode, which may appear as an additional structural element, actually converts the potential harm of close proximity between data line and gate electrode into a benefit by actively reducing parasitic capacitance. The presence of the shielding electrode transforms what would be a harmful coupling into a controlled configuration that improves display quality
Data Source
AI summary
One or more embodiments provide a light-emitting display device including a substrate, a first transistor including a lower electrode above the substrate, a first semiconductor overlapping the lower electrode, and a first gate electrode overlapping the first semiconductor, a light-emitting diode electrically connected to the first transistor, a storage capacitor including a first storage electrode electrically connected to the lower electrode, and a second storage electrode overlapping the first storage electrode, a shielding electrode at a same layer as the lower electrode or as the first semiconductor, a data line overlapping the shielding electrode, and configured to transmit a data voltage, and an auxiliary electrode between the shielding electrode and the data line, overlapping the shielding electrode, and adjacent to the first gate electrode.