Reflective Liquid Crystal Display with Optimized Pre-Tilt Angles
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Reflective liquid crystal display devices face challenges in achieving high contrast images due to disclination and phase shift issues, particularly with vertically aligned liquid crystals, which require precise pre-tilt angles and thickness control, making it difficult to use phase compensators effectively.
Innovation Solution
A reflective liquid crystal display device with vertically aligned nematic liquid crystals, where the liquid crystal orientation on each substrate is set at specific angles relative to the polarized light incidence, eliminating the need for a phase compensator by optimizing the pre-tilt and twist angles to prevent disclination and maintain high contrast.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If vertically aligned liquid crystal is used to achieve high contrast and fast response, then contrast ratio and response speed are improved, but disclination occurs and image quality deteriorates
Solution Approach 1:
The patent changes the pre-tilt angle parameter to a specific range (10-30 degrees) to resolve the contradiction. This parameter modification prevents disclination while maintaining the high contrast and fast response characteristics of vertically aligned liquid crystal, thus improving image quality without sacrificing contrast ratio.
2Illumination intensity
If phase compensator is added to compensate phase shift, then contrast ratio is improved, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent extracts and eliminates the phase compensator component from the display device structure. By setting the pre-tilt angle to a specific range, the invention achieves high contrast without the need for additional phase compensating elements, thereby reducing device complexity and manufacturing difficulty.
Solution Approach 2:
The liquid crystal layer itself serves the dual function of providing high contrast and compensating for phase shifts through its optimized pre-tilt angle configuration. This self-service approach eliminates the need for separate phase compensator components, simplifying the overall device structure.
3Illumination intensity
If pre-tilt angle and cell thickness are precisely controlled, then phase shift is compensated and contrast is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent modifies the pre-tilt angle parameter to a broader acceptable range (10-30 degrees) compared to conventional designs. This parameter change relaxes the manufacturing precision requirements while still achieving effective phase compensation and high contrast ratio, making the device more manufacturable.
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 high-contrast image display without phase compensators, improving image quality and reducing manufacturing complexities by stabilizing the pre-tilt angle and cell thickness within specific ranges, thereby enhancing the display's contrast ratio and brightness.
Implementation Method 1
The liquid crystal display device utilizes the double refraction of the liquid crystal molecules to control the transmission of light passing therethrough
Implementation Method 2
the vertically aligned type of liquid crystal has a negative dielectric anisotropy, so that the liquid crystal molecules are aligned to a direction perpendicular to the substrate surface when no voltage is applied between the substrates. And, in response to an application of voltage, the molecules are made to be aligned horizontally along the substrate surface
Data Source
AI summary
A reflective liquid crystal display device combined with an optical system with a wire grid is provided for light modulation by a liquid crystal layer. This layer, made of nematic liquid crystal having negative dielectric anisotropy, is formed such that first and second orientation directions on first and second substrates are rotated by “60±α” and “60±β” degrees in first and second rotating directions starting from a reference direction, respectively. The first and second rotating directions are mutually opposite, the reference direction is parallel to the first and second substrates and within in an angular range defined by a central angle plus ±5 degrees wherein the central angle is ±45 degrees from an oscillation direction of incident polarized light, and a relationship of |α|+|β|≦10 (α and β are zero or positive integers) is fulfilled.