Light Control Film with Air-Filled Diffusion for High Luminance
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Solution Overview
Problem
Existing light diffusion sheets for liquid crystal display devices suffer from reduced light emission due to absorption by colored low refractive index materials, leading to decreased contrast and efficiency, especially when viewed at oblique angles.
Innovation Solution
A light control film with a light-transmissive base material, a light diffusion portion, and a light shielding layer, where the light diffusion portion is thicker than the light shielding layer, and the low refractive index portion is filled with air or inert gas, with a tilted surface that spreads from the light emission end to the light incidence end, and the light shielding layer is made of black resin or metal oxides, ensuring a specific area ratio and tilt angle configuration to enhance light distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a light diffusion sheet uses colored low refractive index material to widen viewing angle, then viewing angle is improved, but light absorption increases and luminance decreases
Solution Approach 1:
The patent extracts and removes the colored low refractive index material that causes light absorption. Instead, it uses air or inert gas filling in the spaces between prisms, which have low refractive indices but do not absorb light. This eliminates the harmful absorption effect while preserving the viewing angle widening effect through the refractive index difference between the prism material and the air/gas filling.
Solution Approach 2:
The patent introduces air or inert gas into the spaces between prisms as a filling medium. These gases have low refractive indices that enable viewing angle widening but do not absorb light like colored materials. This creates an inert optical environment that prevents light absorption while maintaining the desired optical functionality.
2Adaptability or versatility
If a light diffusion sheet uses colored low refractive index material to improve viewing angle, then viewing angle is improved, but light use efficiency decreases
Solution Approach 1:
The patent removes the colored low refractive index material that causes energy loss through absorption. By replacing it with air or inert gas filling, the system eliminates the energy absorption mechanism while maintaining the refractive index difference needed for viewing angle control, thereby improving light use efficiency.
Solution Approach 2:
The use of air or inert gas creates an environment that does not absorb light energy. These gases provide the necessary refractive index contrast for viewing angle widening without the harmful energy absorption effect of colored materials, thus reducing energy loss and improving overall light use efficiency.
3Adaptability or versatility
If a light diffusion sheet uses colored low refractive index material to widen viewing angle, then viewing angle is improved, but contrast decreases
Solution Approach 1:
The patent extracts and eliminates the colored material that absorbs light and degrades contrast. By using air or inert gas instead, the system maintains the refractive index difference needed for viewing angle control while preventing light absorption that would otherwise reduce image contrast and display quality.
Solution Approach 2:
The inert gas or air filling creates an optical environment that does not absorb light across different wavelengths. This prevents the degradation of contrast that occurs with colored materials, while still providing the refractive index contrast necessary for widening the viewing angle, thus maintaining reliable display quality.
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 improves contrast and display quality by minimizing light absorption, maintaining high luminance and efficiency even at wide viewing angles, reducing light loss and enhancing the light use efficiency of the light control film.
Implementation Method 1
low refractive index portion which is filled with a material having a refractive index lower than a refractive index of a material forming the light diffusion portion
Implementation Method 2
a lower side of the trapezoid is a light incidence portion, oblique sides form the total reflection portion, and an upper side forms a light emission portion
Data Source
AI summary
A light control film includes a light shielding layer and a light diffusion portion, and, when an area of a part where the light shielding layer is in contact with one surface of the base material is set to S1, and an area of a part where a low refractive index portion is exposed between light incidence end surfaces is set to S2, the light shielding layer and the light diffusion portion are formed so as to satisfy (S1−S2)/S1×100≥50.