Liquid Crystal Display Color Filter Taper Angle Optimization
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Solution Overview
Problem
Liquid crystal display devices with color filters on the TFT substrate face challenges in achieving a high aperture ratio due to large overlapping regions and abnormal alignment film issues, which are exacerbated by small taper angles and wide signal line widths.
Innovation Solution
The solution involves forming liquid crystal display devices with color filters that have a wide taper angle in contact holes and a small taper angle in overlapping regions, using photolithographic technology and halftone exposure to optimize the angle and thickness of the color filters, thereby reducing the width of signal lines and increasing the aperture ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If color filters are provided on the TFT substrate side, then the protective function for thin film transistors is improved, but the aperture ratio deteriorates due to large overlapping regions
Solution Approach 1:
The patent changes the geometric parameters of the color filter overlapping regions by controlling the taper angle during photolithographic formation. By optimizing the taper angle, the overlapping region area is minimized while maintaining the protective coverage over signal lines and thin film transistors, thus resolving the contradiction between protective function and aperture ratio.
2Ease of manufacture
If the taper angle of color filters is small, then the manufacturing process is simplified, but the alignment film reliability deteriorates due to abnormal alignment
Solution Approach 1:
The patent identifies and optimizes the taper angle parameter within a specific range (30° to 60°) to simultaneously achieve good alignment film formation and acceptable manufacturing complexity. This parameter optimization resolves the contradiction by finding the optimal balance point where alignment reliability is sufficient while maintaining manufacturing feasibility.
3Reliability
If signal line width is increased, then the electrical connection reliability is improved, but the aperture ratio deteriorates
Solution Approach 1:
The patent optimizes the signal line width parameter to minimize the overlapping region area while maintaining adequate electrical connection. By carefully controlling the signal line width and its positioning relative to color filter overlapping regions, the patent achieves both reliable electrical connection and maximized aperture ratio.
4Area of stationary object
If the overlapping region width is reduced, then the aperture ratio is improved, but the protective function deteriorates
Solution Approach 1:
The patent applies different geometric characteristics to different regions of the color filters. The overlapping regions are designed with specific taper angles and widths to provide minimal necessary protection, while the non-overlapping regions maintain full protective coverage. This local differentiation allows reduction of overlapping region width without compromising overall protective function.
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 approach enhances the aperture ratio of the liquid crystal display device by narrowing the signal lines and improving the alignment film reliability, leading to a more efficient light transmission and display performance.
Implementation Method 1
using photolithographic technology and halftone exposure to optimize the angle and thickness of the color filters
Data Source
AI summary
Display device, including: substrates, color filters having first and second color filters, drain and gate signal lines (of light blocking material), wherein, an overlapping portion adjacent the first and second color filter overlap, is formed on a region with one of the drain or gate signal lines, a first color filter edge is a first taper and a second color filter edge is a second taper, in the overlapping portion, the first taper is closer to the drain or gate signal line than the second taper in the overlapping portion, the first taper angle is 45° or more and 90° or less corresponding to a surface of the drain or gate signal line, the second taper angle is 45° or more and 90° or less corresponding to a surface of the first taper and, the first taper angle is larger than the second taper angle.