Electro-Optical Gate Layout for High-Speed Signal Writing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electro-optical devices face challenges in high-speed driving due to performance differences between N-channel and P-channel transistors, primarily caused by equivalent capacitive couplings with light shielding films covering both transistors, leading to waveform rounding and insufficient signal writing.
Innovation Solution
The electro-optical device is designed with a light shielding film configuration where the film overlaps with one transistor but not the other, and employs a dual light shielding film system with varying light shielding properties to minimize capacitive coupling and performance differences, ensuring high-speed operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the light shielding film covers the entire region of the transmission gate in plan view, then the light shielding effect is improved, but the capacitive coupling between the light shielding film and wiring lines becomes equivalent for both N-channel and P-channel transistors, preventing elimination of performance differences
Solution Approach 1:
The light shielding film is designed with different coverage areas for N-channel and P-channel transistors. Specifically, the light shielding film covers the P-channel transistor but not the N-channel transistor, creating asymmetric light shielding that compensates for the inherent performance differences between the two transistor types. This local differentiation in light shielding coverage allows the weaker P-channel transistor to be protected from light interference while the N-channel transistor maintains its superior performance characteristics.
2Object-affected harmful factors
If the light shielding film covers the entire region of the transmission gate, then light entering the transistor is blocked, but waveform rounding increases and signal writing becomes insufficient at high speeds
Solution Approach 1:
The light shielding film is strategically positioned to cover only the P-channel transistor region while leaving the N-channel transistor region uncovered. This asymmetric configuration reduces the overall capacitive coupling effect and minimizes waveform rounding, thereby improving signal writing speed while still providing necessary light shielding protection to the P-channel transistor.
3Speed
If asymmetric light shielding film coverage is applied to compensate for transistor performance differences, then high-speed driving capability is improved, but the device complexity increases
Solution Approach 1:
The light shielding film is segmented into different coverage regions corresponding to different transistor types. Instead of a uniform coverage, the film is divided such that it covers the P-channel transistor but not the N-channel transistor. This segmentation approach, while increasing configuration complexity, enables optimized performance for each transistor type and achieves high-speed driving capability.
Data Source
AI summary
An electro-optical device includes: a first substrate; a second substrate; an electro-optical layer disposed between the first substrate and the second substrate; a display region including a plurality of pixels; and a peripheral area provided outside the display region, in which the first substrate includes: a transmission gate including an N-channel type transistor and a P-channel type transistor; an electrical conducting section closer to the electro-optical layer than the transmission gate; and a light shielding film closer to the electro-optical layer than the electrical conducting section, and the light shielding film overlaps with the electrical conducting section and one of the N-channel type transistor and the P-channel type transistor in plan view, and does not overlap with the other one of the N-channel type transistor and the P-channel type transistor in plan view.