Thin Film Transistor Array Substrate Storage Capacitor Aperture Ratio
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Solution Overview
Problem
Existing thin film transistor array substrates face challenges in increasing storage capacitor capacity without compromising the aperture ratio, which affects the uniformity and performance of liquid crystal display panels.
Innovation Solution
A thin film transistor array substrate design that incorporates a light shielding electrode with a transparent and non-transparent electrically-conductive layer stack, and a storage capacitor with electrodes in the same layer as the light shielding electrode, utilizing a peripheral drive circuit to provide potential to the first electrode of the storage capacitor, allowing for increased storage capacitor capacity without additional mask processes and maintaining the aperture ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a storage capacitor is added to improve picture uniformity, then the storage capacitor capacity increases, but the aperture ratio decreases
Solution Approach 1:
The storage capacitor electrode is merged with the light shielding electrode structure. The first electrode of the storage capacitor is formed in the same layer as the transparent electrically-conductive layer of the light shielding electrode, combining two functional elements into a single integrated structure. This allows the storage capacitor to be added without occupying additional pixel area, thus maintaining the aperture ratio while improving picture uniformity.
Solution Approach 2:
The transparent electrically-conductive layer serves multiple functions: it acts as both the light shielding electrode and the first electrode of the storage capacitor. By making this layer multi-functional, the patent eliminates the need for separate electrode structures, thereby avoiding reduction in aperture ratio while still providing the necessary storage capacitor functionality for picture uniformity.
2Reliability
If a storage capacitor is added to enhance display performance, then the storage capacitor capacity increases, but the device complexity increases due to additional mask processes
Solution Approach 1:
The patent combines the storage capacitor electrode formation with the existing light shielding electrode formation process. Both electrodes are formed in the same layer using the same transparent electrically-conductive material and the same patterning steps, eliminating the need for additional mask processes and reducing device complexity.
Solution Approach 2:
The existing transparent electrically-conductive layer structure serves dual purposes: light shielding and storage capacitor electrode. The layer's inherent properties and positioning allow it to fulfill both functions without requiring separate processing steps, making the system self-sufficient and reducing overall process complexity.
Data Source
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AI summary
The invention provides a thin film transistor array substrate including: a substrate; a plurality of pixel elements disposed on the substrate, each of the pixel elements including a thin film transistor and a pixel electrode electrically connected with the thin film transistor; a light shielding electrode disposed between the substrate and the thin film transistor to shield a channel of the thin film transistor; and a storage capacitor including a first electrode and a second electrode disposed opposite to each other. With the thin film transistor array substrate according to the invention for which the design of the storage capacitor is improved, the storage capacitor can be added without lowering an aperture ratio to thereby improve the uniformity of a picture and other performances of the display panel effectively.