Patterned Obscuration for UV-Cured LOCA Automotive Glazing
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Solution Overview
Problem
The existing glazing technologies in vehicles face challenges with optical distortion and residual stress due to variations in thickness and surface mismatch during the lamination process, which are exacerbated when used with camera systems and other advanced technologies.
Innovation Solution
The use of a laminated glazing with a light curable Liquid Optically Clear Adhesive (LOCA) layer, which allows for the bonding of glass layers even when obscured on both sides, and a patterned obscuration that allows for the transmission of light to cure the LOCA, thereby reducing optical distortion and residual stress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a solid plastic interlayer is used for lamination, then the glass layers can be bonded together, but optical distortion and residual stress occur due to thickness variation and surface mismatch
Solution Approach 1:
The patent replaces the solid plastic interlayer (mechanical bonding system) with a liquid optically clear adhesive (LOCA) that cures to form a bonded joint. This substitution eliminates the thickness variation and surface mismatch problems associated with solid interlayers, as the liquid adhesive can flow to accommodate surface irregularities and then cure to a uniform thickness, thereby resolving the contradiction between bonding strength and optical quality
Solution Approach 2:
The patent changes the physical state of the bonding material from solid (interlayer) to liquid (LOCA) during the bonding process. The liquid state allows the adhesive to flow and conform to surface variations, and upon curing, it achieves both strong bonding and optical clarity. This parameter change resolves the contradiction by allowing the bonding material to adapt to thickness variations while maintaining optical quality
2Manufacturing precision
If a light curable LOCA layer is used to bond glass layers, then optical quality improves, but the obscuration blocks light needed to cure the LOCA
Solution Approach 1:
The patent segments the obscuration into a patterned design with voids or transparent regions that allow light to pass through. This segmentation enables the obscuration to maintain its aesthetic and protective functions while creating pathways for UV light to reach and cure the LOCA in specific areas, thereby resolving the contradiction between optical quality and ease of manufacture
Solution Approach 2:
The patent applies local quality by making the obscuration patterned rather than solid, creating specific regions (voids) where light transmission is allowed. This localized modification enables the obscuration to block light in most areas (maintaining aesthetic/protective function) while permitting light through specific patterns (enabling LOCA curing), thus resolving the contradiction
3Productivity
If standard lamination process is used, then the process is simple and fast, but sensitive components cannot withstand the heat and pressure
Solution Approach 1:
The patent replaces the thermal and mechanical lamination process (heat and pressure) with a photopolymerization process using UV light to cure the LOCA. This substitution eliminates the need for high heat and pressure, allowing sensitive components to remain in the glazing assembly without damage, while still achieving strong bonding and maintaining productivity through rapid UV curing
Solution Approach 2:
The patent changes the curing mechanism from thermal/pressure-based to light-based (photopolymerization). This parameter change allows the bonding process to occur at ambient temperature and pressure, making the process compatible with heat-sensitive and pressure-sensitive components, thereby resolving the contradiction between productivity and component tolerance
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
This solution improves the optical quality of the glazing, allows for the use of thicker and irregularly shaped inserts, and enables the integration of sensitive components that cannot withstand the standard lamination process, while maintaining the aesthetic and protective qualities of solid obscurations.
Implementation Method 1
a light curable Liquid Optically Clear Adhesive (LOCA) layer, which allows for the bonding of glass layers even when obscured on both sides, and a patterned obscuration that allows for the transmission of light to cure the LOCA
Data Source
Figure 1A~1B
Figure 2A~2B
Figure 3A~3B
AI summary
With the trend towards full autonomous vehicles, as well as consumer demand for increased levels of comfort, convenience, and safety, the complexity of modern automotive glazing has been increasing at a rapid rate as the glazing becomes an integral part of the technology. Laminates, in particular, now often come equipped with camera systems, antennas, de-icing circuits, variable light transmission, embedded lighting and displays. Many of these require components within the glazing. With conventional plastic interlayers, these components must be substantially flat and a fraction of the thickness of the interlayer. Attempts have been made to use UV cured liquid optically clear adhesives in place of the solid plastic interlayer. However, the obscuration printed on the glass layers does not transmit UV. The invention provides a modified obscuration that allows transmission of sufficient UV while maintaining the aesthetics of a solid opaque obscuration.