VA LCD Phase Difference Film Side Light Leakage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Liquid crystal display apparatuses in vertical alignment mode face challenges in achieving high contrast ratios due to light leakage from side light, which affects image quality.
Innovation Solution
Incorporating a phase difference film with specific in-plane and thickness retardation values between the liquid crystal layer and the polarizing plates, along with strategically positioned A- and negative C-plates, to control the polarization state of side light and prevent leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a vertical alignment mode liquid crystal display apparatus is used, then the contrast ratio is improved, but side light leakage occurs affecting image quality
Solution Approach 1:
A phase difference film is introduced as an intermediary element between the liquid crystal layer and the polarizing plate. This film has specific optical properties (in-plane retardation of 100-200 nm and thickness retardation of 200-400 nm) that modify the polarization state of side light, preventing it from leaking through the polarizing plate while maintaining the high contrast ratio characteristic of VA mode displays.
Solution Approach 2:
The invention changes the optical parameters of the display system by introducing a phase difference film with specific retardation values. The in-plane retardation (Re) is controlled at 100-200 nm and thickness retardation (Rth) at 200-400 nm, which transforms the polarization characteristics of light passing through the liquid crystal layer, thereby suppressing side light leakage without compromising the contrast ratio.
2Object-generated harmful factors
If phase difference film with specific retardation values is added, then side light leakage is reduced, but device complexity increases
Solution Approach 1:
The phase difference film is segmented into functional layers with specific optical characteristics. By dividing the optical compensation function into distinct layers with defined retardation properties, the invention achieves effective side light suppression while maintaining a relatively simple overall structure that can be integrated into existing VA mode display architectures.
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 significantly improves the contrast ratio by reducing side light leakage, enhancing image clarity and maintaining high contrast across various viewing angles.
Implementation Method 1
a phase difference film disposed between the second polarizing plate and the liquid crystal layer, the phase difference film having an in-plane retardation value of about 120 nm to about 150 nm and a thickness retardation value of about 240 nm to about 300 nm
Implementation Method 2
The intensity of an electric field applied to the liquid crystal material is controlled to regulate the amount of light passing through the two substrates
Implementation Method 3
The liquid crystal display apparatus driven in the VA mode includes liquid crystal molecules that are homeotropically aligned with the two substrates and have a negative dielectric constant
Implementation Method 4
a first polarizing plate disposed on an outer surface of the array substrate, the first polarizing plate including a first transmission axis; a second polarizing plate disposed on an outer surface of the opposite substrate, the second polarizing plate including a second transmission axis perpendicular to the first transmission axis
Data Source
AI summary
A liquid crystal display apparatus includes a liquid crystal display panel including an array substrate, an opposite substrate and a liquid crystal layer, a first polarizing plate disposed on an outer surface of the array substrate and including a first transmission axis, a second polarizing plate disposed on an outer surface of the opposite substrate and including a second transmission axis, a phase difference film disposed between the second polarizing plate and the liquid crystal layer, and a backlight unit providing light to the first polarizing plate. The phase difference film has an in-plane retardation value of about 120 nm to about 150 nm and a thickness retardation value of about 240 nm to about 300 nm.