Foldable Circular Polarizing Plate Retardation Optimization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current compensation films for OLED displays do not effectively match the ideal phase difference, leading to external light reflection and leakage, particularly in foldable organic light emitting diode displays, which affects visibility and contrast ratio.
Innovation Solution
A foldable circular polarizing plate and compensation film with a liquid crystal layer that absorbs light in wavelengths less than or equal to 420 nm, featuring specific in-plane retardation relationships and absorption rates to enhance anti-reflection effects, while maintaining high transmittance in the visible region.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a conventional compensation film is used in OLED display, then the device structure is simple, but external light reflection and leakage occur due to insufficient phase difference matching
Solution Approach 1:
The patent uses a composite compensation film combining liquid crystal molecules with specific birefringence characteristics and a polymer matrix. The liquid crystal layer with controlled in-plane retardation (Re) values at different wavelengths (450nm, 550nm, 650nm) works together with the polymer substrate to achieve ideal phase difference matching, effectively preventing external light reflection and leakage while maintaining structural integrity.
Solution Approach 2:
The patent optimizes the in-plane retardation parameters of the liquid crystal layer at three specific wavelengths (450nm, 550nm, 650nm) to satisfy specific mathematical relationships. By precisely controlling these optical parameters, the compensation film achieves optimal phase difference matching for the OLED display, eliminating the reflection and leakage problems caused by conventional films with inadequate parameter matching.
2Object-affected harmful factors
If the compensation film absorbs more short wavelength light to improve anti-reflection effect, then external light reflection is reduced, but transmittance in the visible region decreases
Solution Approach 1:
The patent applies selective light absorption only in the ultraviolet region (wavelengths below 420nm) through the liquid crystal layer, while maintaining high transmittance in the visible region (430nm-780nm). This localized absorption approach targets only the harmful short wavelength light that causes reflection issues, without compromising the brightness and visibility of the display in the visible spectrum.
Solution Approach 2:
The patent utilizes the wavelength-dependent optical properties of the liquid crystal layer to selectively interact with different portions of the light spectrum. The liquid crystal molecules are configured to absorb ultraviolet light while remaining transparent to visible light, effectively filtering harmful short wavelengths without affecting the color and brightness of the displayed image.
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 solution significantly improves the anti-reflection effect of external light, reducing light leakage and enhancing the display's visibility and contrast ratio, particularly in foldable OLED displays by optimizing the phase difference and absorption characteristics.
Implementation Method 1
the compensation film is configured to absorb light in a wavelength region of less than or equal to 420 nm
Implementation Method 2
the linear polarized light is shifted into circularly polarized light by using a polarizer and a compensation film
Data Source
AI summary
A foldable circular polarizing plate includes a polarizer and a foldable compensation film disposed on one surface of the polarizer, wherein in-plane retardations of the liquid crystal layer at 450 nm, 550 nm, and 650 nm wavelengths satisfy Relationship Equations 1 or 2, the compensation film is configured to absorb light in a wavelength region of less than or equal to 420 nm, and a reflection color in a CIE-Lab color coordinate system satisfies Δa*b*≤5.0 and a foldable organic light emitting diode display including the same.Re(450 nm)<Re(550 nm)≤Re(650 nm) [Relationship Equation 1]Re(450 nm)≤Re(550 nm)<Re(650 nm) [Relationship Equation 2]