Optical Film Micro-Structures for Oblique Viewing Angle
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Display devices suffer from a color washout problem when viewed at oblique angles, leading to a suboptimal display effect due to reduced light diffusion and luminance at wide viewing angles.
Innovation Solution
An optical film with micro-structures extending along a specific direction, arranged side by side with a pitch greater than 10 times the wavelength of incident light, is integrated into the display device. This film increases the light diffusion angle by using a first layer with a refractive index less than the second layer, ensuring more light is emergent at oblique viewing angles, thereby improving image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional display devices are used without special optical films, then the structure is simple and cost is low, but the viewing angle is limited and color washout occurs at oblique angles
Solution Approach 1:
The optical film is divided into multiple layers (first layer and second layer) with distinct functions. The first layer contains micro-structures for light diffusion, while the second layer provides support and additional optical control. This segmentation allows each layer to be optimized for its specific function, improving overall viewing angle performance without excessive complexity.
Solution Approach 2:
The first layer incorporates micro-structures with pitch greater than 10 times the wavelength of incident light, creating a porous-like structure that enables effective light diffusion. This porous configuration allows light to scatter in multiple directions, significantly expanding the viewing angle while maintaining a relatively simple film structure.
2Illumination intensity
If the pitch between micro-structures is small, then the film structure is compact, but light diffusion angle is insufficient and oblique viewing quality deteriorates
Solution Approach 1:
The patent specifies that the pitch between adjacent micro-structures should be greater than 10 times the wavelength of incident light. This parameter change from conventional small-pitch structures enables effective light diffusion by allowing light waves to interact with multiple micro-structures, thereby increasing the light diffusion angle and improving oblique viewing quality.
3Illumination intensity
If refractive index of first layer is greater than second layer, then light control is simplified, but light diffusion efficiency is reduced and oblique viewing luminance decreases
Solution Approach 1:
The patent specifies that the refractive index of the first layer should be less than that of the second layer. This refractive index configuration creates optimal conditions for light diffusion at the interface between layers, enhancing light scattering efficiency and improving luminance at oblique viewing angles while maintaining reasonable structural complexity.
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 optical film enhances the quality of images displayed at oblique viewing angles by increasing light diffusion and reducing luminance and contrast loss, making images more consistent across different viewing angles.
Implementation Method 1
The first layer has a refractive index less than the second layer... increases the light diffusion angle... ensuring more light is emergent at oblique viewing angles
Data Source
AI summary
An optical film including a first layer and a second layer disposed on the first layer and attached to the first layer is provided. The first layer has a plurality of micro-structures respectively extending along a first direction and arranged side by side at an interval. The micro-structures protrude toward the second layer. A first pitch exists between each micro-structure and an adjacent micro-structure in a side-by-side arrangement direction. The first pitch is greater than 10 times a wavelength of an incident light. Moreover, a display device including the foregoing optical film is also provided.