Curved Vehicle Window LC Shading With Expansion Compensation
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Solution Overview
Problem
Existing vehicle windows with liquid crystal arrangements struggle to provide uniform shading on three-dimensionally curved surfaces, leading to inconsistent light transmittance and color limitations.
Innovation Solution
A vehicle window design featuring a plate-like, curved glass or plastic window body with a liquid crystal arrangement sandwiched between two films, connected via a linear expansion compensation layer to maintain consistent light transmission and absorb thermal stresses, allowing for three-dimensional curvature and efficient switching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a liquid crystal arrangement is applied to a three-dimensionally curved window body, then the window can provide shading functionality, but uniform light transmittance and consistent shading behavior cannot be achieved
Solution Approach 1:
The liquid crystal arrangement is bonded between two flexible films that can conform to three-dimensional curved surfaces. The films are made of elastomeric material with appropriate elastic modulus to accommodate curvature while maintaining uniform liquid crystal cell thickness, enabling consistent optical properties across curved window surfaces.
Solution Approach 2:
The patent controls the elastic modulus of the elastomeric films to match or exceed that of the liquid crystal material, preventing film deformation that would cause non-uniform cell thickness. This parameter control ensures uniform liquid crystal alignment and consistent light transmittance across curved surfaces.
2Strength
If the liquid crystal arrangement is directly bonded to the curved window body, then structural integrity is maintained, but thermal stress and delamination occur due to different thermal expansion coefficients
Solution Approach 1:
An intermediate elastomeric film layer is introduced between the rigid window body and the liquid crystal arrangement. This intermediate layer has thermal expansion properties that bridge the gap between glass/plastic and liquid crystal materials, absorbing thermal stress and preventing delamination while maintaining structural integrity.
Solution Approach 2:
The elastomeric films are specifically selected to have thermal expansion coefficients that compensate for the mismatch between the window body and liquid crystal materials. This thermal expansion compensation prevents stress buildup during temperature cycles, ensuring long-term reliability.
3Strength
If additional adhesive layers are used to bond the liquid crystal arrangement, then bonding strength is improved, but device complexity and manufacturing steps increase
Solution Approach 1:
The bonding function is merged into the elastomeric films themselves, which serve both as structural support and as the bonding medium. The films are made from materials with inherent adhesive properties, eliminating the need for separate adhesive layers and simplifying the overall structure.
Solution Approach 2:
The elastomeric films perform multiple functions simultaneously: providing mechanical support, accommodating curvature, compensating for thermal expansion, and providing bonding adhesion. This multi-functionality reduces the total number of components and simplifies manufacturing.
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 ensures uniform shading with constant light transmittance over the window surface, low voltage operation, and quick switching times, while eliminating the need for additional adhesive layers and providing a customizable gray color.
Implementation Method 1
They have a milky appearance. However, when voltage is applied to the corresponding liquid crystal cells, the liquid crystals align, allowing light transmission.
Implementation Method 2
The linear expansion compensation layer, which can be designed to be elastic, absorbs stresses that can arise, for example, due to different thermal expansion behavior between the pane body and the liquid crystal arrangement.
Implementation Method 3
The vehicle window comprises a plate-like window body, which is usually made of glass and forms the outer skin of the roof element. On its inner side, the window body is provided with a liquid crystal arrangement that is electrically switchable and thus determines the light transmittance of the vehicle window.
Data Source
Figure 1
Figure 2a
Figure 2b
AI summary
The invention relates to a vehicle window, comprising a plate-like window body (16) which has an outer side facing a vehicle environment and an inner side facing away from the outer side and wherein a shading arrangement is arranged on the inside thereof, which is formed by a liquid crystal arrangement (20) that has a liquid crystal cell (26). The liquid crystal arrangement (20) comprises two films (22, 24), between which the liquid crystal cell (26) is arranged, and is connected to the window body (16) by at least one longitudinal expansion compensation layer (28).