Ferroelectric LCD with Reflective Common Electrode
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Solution Overview
Problem
Conventional liquid crystal display (LCD) devices face challenges in achieving a thin, lightweight, and cost-effective design due to the thickness and rigidity of polarizers, which affect viewing angle efficiency and flexibility, and require additional compensation plates for reflective modes, complicating light transmission and manufacturing.
Innovation Solution
The use of ferroelectric liquid crystal materials with spontaneous polarization for alignment layers and a nematic liquid crystal layer with dye material, allowing for dynamic rotation and reducing the need for multiple polarizers, thereby enhancing brightness and aperture ratio while omitting the compensation plate in reflective modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If two polarizers are used in the LCD device, then the desired gray level can be obtained through birefringence control, but the device thickness increases and flexibility is reduced
Solution Approach 1:
The patent extracts and eliminates one of the two polarizers from the conventional LCD structure. By using a reflective common electrode instead of a second polarizer, the device achieves gray level control through a single polarizer combined with reflective modulation, thereby reducing thickness while maintaining display functionality
Solution Approach 2:
The common electrode is given multiple functions: it serves as both the common electrode for voltage application and as a reflective surface for light modulation. This multi-functionality replaces the need for a second polarizer, reducing the number of components while maintaining gray level control capability
2Reliability
If two polarizers are used in the LCD device, then the liquid crystal molecules can be effectively controlled, but the device weight increases
Solution Approach 1:
The patent removes one polarizer from the dual-polarizer configuration, directly reducing the weight of the device. The reflective common electrode compensates for the removed polarizer's function, maintaining liquid crystal control efficiency while achieving weight reduction
3Reliability
If a compensation plate is added for reflective mode, then the retardation ratio is compensated, but the device complexity and manufacturing cost increase
Solution Approach 1:
The common electrode serves dual purposes: as the common electrode for electrical control and as the reflective surface for optical modulation. This integration eliminates the need for a separate compensation plate, reducing structural complexity while maintaining reflective mode functionality
Solution Approach 2:
The patent merges the common electrode and reflective surface into a single component. By combining these functions in one element, the device structure is simplified and manufacturing steps are reduced, eliminating the need for an additional compensation plate
4Illumination intensity
If a compensation plate is added for reflective mode, then the light transmission efficiency is improved, but the manufacturing cost increases
Solution Approach 1:
The common electrode and reflective surface are combined into one component, reducing the total number of parts that need to be manufactured and assembled. This integration lowers manufacturing complexity and cost while maintaining light transmission efficiency through the reflective mechanism
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 results in a lighter, thinner, and more cost-effective LCD device with improved brightness and flexibility, as well as reduced manufacturing costs by eliminating the need for additional polarizers and compensation plates.
Implementation Method 1
a first alignment layer of a ferroelectric liquid crystal material over the pixel electrode, the first alignment layer having a first spontaneous polarization along a first direction; a second alignment layer of the ferroelectric liquid crystal material over the common electrode, the second alignment layer having a second spontaneous polarization along the first direction
Implementation Method 2
The birefringence is varies according to a vertical electric field between the common electrode 18. and the pixel electrode 36 when the electric field is applied to the liquid crystal layer 40
Implementation Method 3
a first polarizer disposed on an outer surface of one of the first substrate and the second substrate
Data Source
AI summary
A liquid crystal display device includes: a first substrate and a second substrate facing each other; a pixel electrode on an inner surface of the first substrate; a first alignment layer of a ferroelectric liquid crystal material over the pixel electrode, the first alignment layer having a first spontaneous polarization along a first direction; a common electrode on an inner surface of the second substrate; a second alignment layer of the ferroelectric liquid crystal material over the common electrode, the second alignment layer having a second spontaneous polarization along the first direction; a liquid crystal layer in between the first alignment layer and the second alignment layer, the liquid crystal layer including a nematic liquid crystal material and a dye material; and a first polarizer disposed on an outer surface of one of the first substrate and the second substrate.