Dual-Substrate TFT LCD Overlapping Wiring Aperture Ratio
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Solution Overview
Problem
The aperture ratio of TFT-LCDs is low, which reduces energy utilization and is challenging to improve without affecting the resolution, especially due to the requirement for broader metal wires and thicker circuits in larger displays.
Innovation Solution
The TFT circuits are arranged on both an upper and a lower substrate such that the gate and data wirings can be completely overlapped, allowing for increased aperture ratio without occupying additional space and maintaining resolution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If TFT circuits are arranged on both upper and lower substrates with overlapping gate and data wirings, then aperture ratio is improved, but device complexity increases
Solution Approach 1:
The patent merges the gate and data wirings of the upper and lower substrates by arranging them to completely overlap each other. This combining approach allows both substrates to share the same wiring space, reducing the total area occupied by circuits and thereby improving the aperture ratio without requiring additional space.
Solution Approach 2:
The patent utilizes the third dimension (vertical stacking) by arranging TFT circuits on both upper and lower substrates. By moving from a single-plane to a multi-plane configuration, the wiring can overlap in the vertical direction, effectively increasing the aperture ratio without expanding the horizontal display area.
2Length of stationary object
If metal wires are broadened and circuits are thickened for larger displays, then display size is improved, but aperture ratio deteriorates
Solution Approach 1:
The patent resolves this contradiction by transitioning to a multi-layer substrate structure. By arranging circuits on both upper and lower substrates with overlapping wirings, the display can achieve larger size while maintaining thin circuit profiles in the horizontal plane, thus preserving the aperture ratio that would otherwise be reduced by broader wires.
Data Source
AI summary
Provided is a thin film transistor (TFT) liquid crystal display device, which is characterized in that an upper substrate is a substrate on which a series of TFT circuits are arranged, and a lower substrate is a thin film transistor TFT substrate. Common electrodes and pixel electrodes of the upper substrate and the lower substrate are alternately configured. The common electrode and pixel electrode of the upper substrate are respectively overlapped with the pixel electrode and common electrode of the lower substrate, so that positions of data lines and scanning lines of the upper substrate and positions of data lines and scanning lines of the lower substrate are overlapped. Thus, in an area corresponding to one scanning line and one data line originally, an original situation that only one pixel may be driven is changed into a situation that the upper and lower substrates both may drive one pixel, so that under the condition that resolutions are the same, the area occupied by the scanning line and the data line is reduced, thereby improving the aperture ratio.