Alternating Pretilt Angles in IPS Display Panels
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
IPS display mode experiences light leakage and color shift issues due to non-zero pretilt angles of liquid crystal molecules, leading to inconsistent light leakage colors, especially in dark states.
Innovation Solution
A display panel design with alternating pretilt angles for liquid crystal molecules in adjacent pixel units, where the first pretilt angle aligns with the substrate direction and the second pretilt angle opposes it, compensated by topographically designed planarization layers to create different optical path differences, which neutralize color shifts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If IPS display mode uses horizontal electric field to control liquid crystal molecules, then display viewing angle and transmittance are improved, but light leakage and color shift occur due to non-zero pretilt angles
Solution Approach 1:
The pixel units are divided into first pixel units and second pixel units with different pretilt angle configurations. This segmentation allows different regions to have different optical characteristics, enabling the overall display to achieve better viewing angle and transmittance while reducing light leakage through complementary arrangement.
Solution Approach 2:
Different pixel units are assigned different pretilt angles (first pretilt angle for first pixel units, second pretilt angle for second pixel units). This local quality variation allows each region to be optimized for specific viewing directions, improving overall transmittance while the alternating pattern compensates for light leakage in different directions.
2Ease of manufacture
If liquid crystal molecules have non-zero pretilt angle for alignment, then manufacturing is simplified, but color shift occurs due to inconsistent optical path differences
Solution Approach 1:
The patent introduces asymmetric pretilt angle configurations where first pixel units have a first pretilt angle and second pixel units have a second pretilt angle. This asymmetric design breaks the uniformity that causes color shift, allowing the alternating pattern to compensate for optical path differences and achieve better color consistency while maintaining simple alignment processes.
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
The alternating pretilt angles compensate for optical path differences, reducing color shift and light leakage issues in the dark state, ensuring consistent display colors across viewing angles.
Implementation Method 1
The liquid crystal molecules corresponding to the first pixel unit form a first pretilt angle. The liquid crystal molecules corresponding to the second pixel unit form a second pretilt angle.
Implementation Method 2
The alternating pretilt angles compensate for optical path differences, reducing color shift and light leakage issues in the dark state
Implementation Method 3
The surface of the first planarization portion is gradually raised along the alignment direction, and the surface of the second planarization portion is gradually lowered along the alignment direction
Data Source
AI summary
A display panel and a display device are disclosed. The display panel includes a first substrate, a second substrate, and a liquid crystal layer disposed therebetween. The first substrate includes a first base and a plurality of pixel units arranged thereon in an array. The pixel units in odd- numbered columns are first pixel units, and those in even-numbered columns are second pixel units. An alignment direction of the first substrate is perpendicular to an extending direction of the column of the pixel units. A liquid crystal molecule corresponding to each first pixel unit defines a first pretilt angle, and that corresponding to each second pixel unit defines a second pretilt angle. An opening direction of the first pretilt angle is consistent with the alignment direction of the first substrate, and an opening direction of the second pretilt angle is opposite to the alignment direction of the first substrate.