Smart Window Optical Stack With Direct Conductive Polarizers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional variable transmittance optical stacks for vehicle windows require additional substrates for forming conductive layers, leading to increased manufacturing complexity, thickness, and transmittance changes due to phase differences.
Innovation Solution
A variable transmittance optical stack is developed without a separate substrate for the conductive layer, directly forming the transparent conductive layer on polarizing plates, which are stacked with a liquid crystal layer driven by an electric field, and includes a refractive index-matching layer to minimize optical differences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a separate or additional substrate is used to form the conductive layer, then the conductive layer can be properly formed and function, but the manufacturing process becomes complicated, manufacturing costs increase, and the thickness of the stack increases
Solution Approach 1:
The patent combines the substrate and conductive layer into a single integrated structure. The transparent substrate itself is formed with a transparent conductive layer through direct deposition or doping processes, eliminating the need for a separate conductive layer and additional substrates. This merging reduces manufacturing complexity while maintaining the electrical conductivity function.
Solution Approach 2:
The transparent substrate is designed to serve multiple functions simultaneously: it provides mechanical support, optical transparency, and electrical conductivity. By making the substrate multi-functional, the patent eliminates the need for separate components, thereby simplifying the manufacturing process and reducing overall device complexity.
2Reliability
If a separate or additional substrate is used to form the conductive layer, then the conductive layer can be properly formed and function, but the thickness of the stack is increased
Solution Approach 1:
The patent merges the substrate and conductive layer into a single integrated component. The transparent substrate is directly formed with conductive properties through methods such as atomic layer deposition (ALD) of transparent conductive oxides or ion implantation, eliminating the need for additional substrate layers and reducing the overall stack thickness.
Solution Approach 2:
The patent employs thin-film deposition techniques to create the transparent conductive layer directly on the substrate. This approach uses ultra-thin conductive films (nanometer scale) instead of thick separate conductive layers, thereby maintaining electrical functionality while minimizing the increase in stack thickness.
3Reliability
If a separate or additional substrate is used to form the conductive layer, then the conductive layer can be properly formed and function, but transmittance changes due to occurrence of phase difference
Solution Approach 1:
The patent integrates the conductive layer formation directly into the substrate manufacturing process. By using techniques such as atomic layer deposition (ALD) or chemical vapor deposition (CVD) to form the transparent conductive layer in-situ on the substrate, the patent eliminates interface mismatches and phase differences that would occur with separate substrates, thereby maintaining consistent transmittance.
Solution Approach 2:
The patent ensures homogeneous optical properties by forming the transparent conductive layer directly on the substrate without introducing additional interfaces. The in-situ formation process creates a uniform, continuous structure with consistent refractive index and optical characteristics across the entire stack, preventing transmittance variations.
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 simplifies the manufacturing process, reduces thickness, and maintains consistent transmittance by eliminating the need for additional substrates, enhancing the stack's flexibility and performance.
Implementation Method 1
a liquid crystal layer driven in response to an electric field
Implementation Method 2
a variable transmittance optical stack capable of changing the transmittance of light when a voltage is applied
Implementation Method 3
a refractive index-matching layer to minimize optical differences
Data Source
AI summary
The present invention relates to a transmittance variable optical stack and a manufacturing method therefor, and a smart window comprising same and a vehicle to which the same is applied, the optical stack comprising polarizing plates stacked on both surfaces thereof with a liquid crystal layer, driven according to an electric field, interposed therebetween, wherein the polarizing plates comprise a polarizer and a protective layer formed on at least one surface of the polarizer, a transparent conductive layer is formed in direct contact with the polarizing plate, and the optical stack has a total light transmittance that changes according to the application of voltage.