FFS LCD Electrode Structure for Uniform Electric Field Distribution
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
FFS LCDs face limitations in viewing angle, chroma, and transmission ratio due to difficulty in fully twisting liquid crystal molecules distal from the substrate, as the electric field generated between the common and pixel electrodes is insufficient to align these molecules effectively.
Innovation Solution
Incorporating a plurality of second common electrodes and floating electrodes on the second substrate, which generate a secondary electric field that cooperates with the primary electric field from the pixel and common electrodes, ensuring uniform electric field strength and effective twisting of all liquid crystal molecules, including those distal from the substrates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If only one common electrode and pixel electrodes are provided on the first substrate, then the device structure is simple, but the electric field cannot effectively align liquid crystal molecules distal from the substrate, resulting in poor viewing angle, chroma, and transmission ratio
Solution Approach 1:
The patent divides the single common electrode into multiple common electrodes (first common electrode on first substrate, second common electrodes on second substrate) and introduces floating electrodes. This segmentation allows the electric field to be distributed more uniformly across the liquid crystal layer thickness, effectively aligning molecules at all distances from the substrates and improving viewing angle and chroma without significantly increasing manufacturing complexity
Solution Approach 2:
The patent transitions from a two-dimensional electrode arrangement (single common electrode on one substrate) to a three-dimensional configuration by placing common electrodes on both substrates and introducing floating electrodes in between. This dimensional expansion creates a more comprehensive electric field distribution that effectively acts on liquid crystal molecules throughout the entire layer, resolving the alignment issue for molecules distal from the substrates
2Manufacturing precision
If the liquid crystal layer thickness is increased to improve viewing angle, then more molecules can be aligned, but the electric field strength from the substrate electrodes decreases, making alignment more difficult
Solution Approach 1:
By segmenting the electrode structure into multiple common electrodes on both substrates and floating electrodes, the patent creates multiple electric field sources that work together. This segmentation allows the electric field to be distributed more uniformly across the liquid crystal layer, maintaining sufficient field strength even when the layer thickness is increased, thereby improving molecule alignment without sacrificing electric field effectiveness
Solution Approach 2:
The floating electrodes act as intermediaries between the common electrodes on the first and second substrates. These floating electrodes generate additional electric fields that fill the gap created by increased liquid crystal layer thickness, ensuring that molecules in the middle and distal regions experience sufficient electric field strength for effective alignment, thus mediating the contradiction between layer thickness and field strength
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 allows for improved viewing angle, chroma, and transmission ratio by ensuring all liquid crystal molecules can be uniformly twisted, addressing the limitations of the conventional FFS LCD.
Implementation Method 1
A liquid crystal display (LCD) utilizes the optical and electrical anisotropy of liquid crystal molecules to produce an image. The liquid crystal molecules have a particular passive orientation when no voltage is applied thereto. However, in a driven state, the liquid crystal molecules change their orientation according to the strength and direction of the driving electric field. A polarization state of incident light changes when the light transmits through the liquid crystal molecules, due to the optical anisotropy of the liquid crystal molecules.
Implementation Method 2
When a voltage is applied to the common electrode and pixel electrodes 111, 113, an electric field 120 is generated between the common electrode and pixel electrodes 111, 113. A direction of the electric field 120 is parallel to the first substrate 110, and perpendicular to the pixel electrodes 113 and the common electrode 111. The long axes of the liquid crystal molecules twist to align in the direction of the electric field 120.
Implementation Method 3
The liquid crystal molecules change their orientation according to the strength and direction of the driving electric field. The long axes of the liquid crystal molecules twist to align in the direction of the electric field 120.
Data Source
AI summary
An exemplary liquid crystal display (LCD) (200) includes a first substrate (210); a second substrate (230) opposite to the first substrate; a liquid crystal layer (250) sandwiched between the first substrate and the second substrate; a first common electrode (211), a first insulating layer (212), and pixel electrodes provided at an inner surface of the first substrate in that order; and second common electrodes (231) and floating electrodes (233) provided at the second substrate. The first common electrode and the pixel electrodes, and the second common electrodes and the floating electrodes, respectively produce two electric fields in the liquid crystal layer corresponding to each other. A combined electric field strength is uniformly distributed in the liquid crystal layer, so that all the liquid crystal molecules can be sufficiently twisted. Thus a viewing angle, a degree of chroma, and a transmission ratio of the LCD are improved.