Wide Source Wiring Shields Spacer Shadow in Display Device
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Solution Overview
Problem
Display devices with active matrix substrates face challenges in shielding alignment failure regions caused by spacers, leading to reduced pixel aperture ratio and light leakage, particularly when using rubbing processing for alignment films.
Innovation Solution
The design includes a display device with an active matrix substrate and a counter substrate, where the active matrix substrate features pixel TFTs, gate wiring lines, and source wiring lines with specific width and orientation configurations to create a first wide width portion that overlaps with and extends beyond the black matrix, effectively shielding the alignment failure regions from light.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the black matrix is enlarged to shield the alignment failure region caused by the spacer, then light leakage is reduced, but the pixel aperture ratio is reduced
Solution Approach 1:
The alignment film serves as an intermediary element that extends into the spacer shadow region to provide alignment restriction force to liquid crystal molecules in the alignment failure region. This allows the black matrix to maintain its original size while still preventing light leakage, as the alignment film compensates for the shielding function in the spacer shadow region.
Solution Approach 2:
The solution extends the alignment film in the depth dimension (into the spacer shadow region) rather than enlarging the black matrix in the horizontal dimension. This dimensional shift allows the alignment film to reach and restrict liquid crystal molecules in regions that would otherwise be unreachable, preventing light leakage without reducing pixel aperture ratio.
2Object-affected harmful factors
If the position and shape of the spacer are adjusted to shield the alignment failure region with the black matrix, then light leakage is reduced, but the manufacturing complexity increases
Solution Approach 1:
The solution extracts the light shielding function from the black matrix and relocates it to the alignment film. By removing the requirement for the black matrix to shield the alignment failure region, the spacer can maintain its standard position and shape, thereby reducing manufacturing complexity while still preventing light leakage through the alignment film's extended coverage.
3Stability of the object's composition
If rubbing processing is performed on the alignment film, then initial alignment of liquid crystal molecules is achieved, but alignment failure occurs in regions above and around the spacer
Solution Approach 1:
The alignment film is preliminarily extended into the spacer shadow region before liquid crystal assembly, ensuring that alignment restriction force is already present in the alignment failure region. This preliminary extension of the alignment film's coverage area prevents alignment failures from occurring in the first place, rather than attempting to correct them afterward.
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 configuration curbs the degradation of display properties by reducing the need for an enlarged black matrix, thereby maintaining a high pixel aperture ratio and improving display contrast without increasing the light shielding area.
Implementation Method 1
Alignment processing of defining an initial alignment azimuth axis of the liquid crystal molecules is performed on the alignment films. Representative examples of the alignment processing include rubbing processing and light alignment processing.
Implementation Method 2
a black matrix that includes a plurality of gate wiring line light shielding portions and a plurality of source wiring line light shielding portions
Implementation Method 3
A liquid crystal display device is configured by sandwiching a liquid crystal layer between an active matrix substrate and a counter substrate
Data Source
AI summary
A display device includes a first source wiring line having a first wide width portion with a second width greater than the first width. The first wide width portion is disposed in a vicinity of one of spacers. The first wide width portion includes an overlapping region overlapping with a black matrix and a non-overlapping region not overlapping with the black matrix when seen in a normal line direction of a main surface of a substrate. A spacer shadow region extending from one spacer to a side of a first direction with an identical width with a width of the one spacer includes a first region overlapping with the black matrix and a second region not overlapping with the black matrix when seen in the normal line direction. The non-overlapping region of the first wide width portion partially overlaps with the second region of the spacer shadow region.