Lens Coating Transfer Using Solid Adhesive Layers
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Solution Overview
Problem
Existing methods for coating lens substrates often result in uneven adhesive layers due to the use of liquid curable adhesives, leading to optical distortions and increased complexity, especially when applied to curved surfaces.
Innovation Solution
A process involving a flexible carrier with a stack of coatings and a pre-deposited transparent adhesive composition, such as pressure-sensitive adhesives or hot-melt adhesives, which is applied in reverse order and pressed onto the lens substrate to achieve a uniform adhesive layer without flowing, ensuring consistent thickness and avoiding liquid adhesives.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If liquid curable adhesive composition is used to transfer coating onto lens substrate, then the coating can be adhered to the lens substrate, but optical distortions occur due to uneven spreading and variations in adhesive layer thickness
Solution Approach 1:
The patent changes the physical state of the adhesive from liquid to solid (or semi-solid) form. This parameter change eliminates the flowability issue that causes uneven spreading, while maintaining adhesion capability through pressure-sensitive or hot-melt mechanisms that activate under controlled conditions.
Solution Approach 2:
The patent replaces the chemical curing mechanism of liquid adhesives with a mechanical bonding mechanism. Solid adhesive layers bond through direct contact and pressure, eliminating the need for liquid flow and chemical curing processes that cause thickness variations and optical distortions.
2Reliability
If liquid curable adhesive composition is used, then coating adhesion is achieved, but the process becomes more complicated and less cost effective due to precise dropping requirements
Solution Approach 1:
The solid adhesive layer performs multiple functions automatically: it provides adhesion, maintains uniform thickness, and eliminates the need for precise dispensing control. The adhesive self-bonds under pressure without requiring complex curing systems or precise application equipment.
Solution Approach 2:
The patent extracts the problematic liquid flow and curing characteristics from the adhesive system, retaining only the essential adhesion function. This simplification removes the need for complex dispensing equipment, curing systems, and quality control mechanisms.
3Ease of operation
If air pressure is used to spread liquid adhesive composition on flexible coating carrier, then coating transfer is achieved, but uneven pressure distribution results in non-uniform adhesive layer thickness
Solution Approach 1:
The patent changes the adhesive from liquid to solid state, eliminating the need for pressure-based spreading. The solid adhesive maintains its deposited thickness uniformly across the carrier surface, and bonding occurs through direct pressure contact rather than pressure-induced flow.
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 method ensures a coated lens substrate with a uniform adhesive layer, reducing the risk of optical distortions and simplifying the coating process by eliminating the need for precise liquid adhesive application, resulting in high optical quality and cost-effectiveness.
Implementation Method 1
bringing said layer of transparent adhesive composition to a state at which the layer becomes unflowable under the process conditions
Implementation Method 2
using pressure-sensitive adhesives or hot-melt adhesives to ensure a consistent adhesive layer thickness
Data Source
Figure 1A~1C
Figure 2A~2C
Figure 3~4
AI summary
The present invention relates to a process for transferring at least one coating onto at least one geometrically defined surface of a lens substrate. In a preferred embodiment, the transparent adhesive composition is selected from the group consisting of pressure-sensitive adhesives and hot-melt adhesives .