Polyimide Film Phase Control for Mura Elimination
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Polyimide-based films used in window cover applications suffer from phase delay issues, leading to mura and rainbow phenomena, which degrade visibility and cause optical stains, especially when polarized light passes through, and existing solutions fail to adequately address these problems.
Innovation Solution
A polyimide-based film is developed that satisfies specific phase difference criteria, expressed as Max[R(θ,ψ0 to 360°)] < R0×[sin(θ)cos(θ)+5 sin(θ)+1] and 1−Min[R(θ50°,ψ0 to 360°)]/Avg[R(θ50°,ψ0 to 360°)] ≤ 50%, ensuring minimal phase difference variations across different angles, thereby preventing mura and rainbow phenomena.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a polyimide-based film is used as a window cover film to protect the display panel, then the display panel is protected from scratches and external shock, but phase delay occurs leading to mura and rainbow phenomena that degrade visibility
Solution Approach 1:
The patent controls the phase difference parameters of the polyimide film at different viewing angles through specific formulation and processing. The film is designed to satisfy specific mathematical expressions for phase difference at various angles, transforming the optical properties to eliminate mura and rainbow phenomena while maintaining protective function
Solution Approach 2:
The patent uses a polyimide-based resin with specific compositional characteristics to create a film that combines mechanical protection with optimized optical properties. The composite nature of the material allows simultaneous achievement of durability and phase difference control
2Adaptability or versatility
If the polyimide-based film has high hardness and stiffness to replace tempered glass, then the window cover film becomes more flexible and lightweight, but phase delay issues persist causing optical stains and visibility deterioration
Solution Approach 1:
The patent modifies the optical parameters of the polyimide film by controlling phase difference at specific viewing angles. The film is engineered to satisfy specific mathematical relationships for phase difference, transforming its optical behavior to prevent mura and rainbow phenomena while maintaining the flexibility and lightweight advantages
3Adaptability or versatility
If coating layers are laminated on the substrate layer to impart various physical properties, then the window cover film gains enhanced functionality, but diffused reflection occurs causing visibility deterioration and eye strain
Solution Approach 1:
The patent optimizes the optical parameters of the polyimide film to minimize diffused reflection. By controlling the phase difference characteristics and optical uniformity of the film, the patent reduces visibility deterioration and eye strain caused by diffused reflection, while the film can still serve as a substrate for functional coating layers
Data Source
AI summary
The present invention relates to a polyimide-based film which does not substantially cause a mura or rainbow phenomenon and has excellent visibility, a window cover film including the same, and a display panel including the same.