Display Pixel Switching Layout to Reduce Mura Defects
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Solution Overview
Problem
Existing display devices face issues with a significant difference in kickback voltage between sub-pixels, leading to mura defects due to luminance differences.
Innovation Solution
The design includes a display device with overlapping contact holes via holes of a color filter to improve aperture ratio, spacing a second switching element from a third switching element, and using a voltage-dividing reference line to equalize voltage distribution across sub-pixels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If contact holes are formed to connect switching elements to pixel electrodes, then electrical connection is achieved, but the aperture ratio is reduced due to the area occupied by contact holes and via holes
Solution Approach 1:
The patent positions contact holes and via holes in overlapping vertical arrangements, utilizing the third dimension (depth) to resolve the area conflict. Contact holes in the color filter layer overlap with via holes in the pixel electrode layer, allowing electrical connection without increasing the planar footprint, thereby maintaining aperture ratio while ensuring reliable electrical connection.
2Productivity
If switching elements are placed close together to increase pixel density, then productivity is improved, but the difference in kickback voltage between sub-pixels increases causing mura defects
Solution Approach 1:
The patent introduces a voltage-dividing reference line as an intermediary element between switching elements. This reference line acts as a mediator to equalize the kickback voltage affecting different sub-pixels, compensating for the voltage differences that arise from close placement of switching elements, thereby preventing mura defects while maintaining high pixel density.
3Illumination intensity
If the aperture ratio is increased to improve display quality, then luminance is enhanced, but the area available for switching elements and contact structures is reduced
Solution Approach 1:
The patent resolves layout constraints by utilizing vertical stacking and overlapping structures. Contact holes and via holes are arranged in overlapping vertical columns, allowing the electrical connection structures to occupy minimal planar area. This enables the pixel aperture to be maximized for improved luminance while still accommodating all necessary switching elements and contact structures within the available space.
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 reduces the difference in kickback voltage between sub-pixels, minimizing mura defects and enhancing image quality by improving voltage uniformity.
Implementation Method 1
the capacitance of gate-drain capacitors is controlled by adjusting the overlap areas of drain electrodes with the gate line
Data Source
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AI summary
A display device (1) includes a gate line (SL) extended in a first direction (DR1) and a data line (DL) extended in a second direction (DR2) crossing the first direction (DR1); a first switching element (T1) including a first source electrode (SE1) connected to the data line (DL), a first drain electrode (DE1), and a first gate electrode (GE1) connected to the gate line (SL); and a second switching element (T2) including a second source electrode (SE2) connected to the data line (DL), a second drain electrode (DE2), and a second gate electrode (GE2) connected to the gate line (SL). A region of the first drain electrode (DE1) overlapping the first gate electrode (SL) extends in the second direction (DR2), the second source electrode (SE2) is extended in the second direction (DR2), and is parallel with the first and second drain electrodes (DE1, D2). A region of the second drain electrode (DE2) overlapping the second gate electrode (SL) includes a first region (DE2_2) extended in the first direction (DR1) and a second region (DE2_1) extended in the second direction (DR2).