Quantum Dot Optical Film for Uniform Backlight Distribution

The patent applies local quality by creating a multi-layer optical film structure where each layer has different properties. The first layer contains red quantum dots with specific refractive index, the second layer contains green quantum dots with different refractive index, and the third layer contains blue quantum dots. This local differentiation of material properties in each layer compensates for the viewing angle-dependent chromaticity variations, achieving consistent color appearance across different viewing angles while maintaining full-color display capability.

The patent segments the optical film into multiple layers, each layer containing quantum dots of a specific color (red, green, blue) with tailored refractive indices. This segmentation allows independent optimization of each layer's optical properties to achieve uniform light distribution across different viewing angles. The multi-layer structure enables better control over light emission characteristics compared to a single-layer film, while maintaining reasonable device complexity through systematic design.

The patent employs parameter changes by carefully selecting and adjusting the refractive index of quantum dot materials in each layer. The first layer uses red quantum dots with a first refractive index, the second layer uses green quantum dots with a second refractive index, and the third layer uses blue quantum dots with a third refractive index. By changing and optimizing these refractive index parameters across layers, the patent achieves both high brightness from quantum dot luminescence and chromaticity consistency across viewing angles by compensating for the inherent refractive index differences.