Optically Variable Security Thread Layering
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current security threads and stripes used in documents lack sophistication in design and flexibility, making them vulnerable to counterfeiting and illegal reproduction, as they often result in thick and difficult-to-integrate holographic structures with limited color combinations and low flexibility.
Innovation Solution
A security thread or stripe comprising a transparent substrate, an optically variable layer, and a color constant layer, combined with a holographic metallic layer, where the optically variable layer changes color with viewing angle and the color constant layer remains consistent, providing enhanced visual attractiveness and increased resistance to counterfeiting through dynamic visual effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional holographic structures are used in security threads, then security protection is provided, but the threads become thick and difficult to integrate into documents
Solution Approach 1:
The security thread is divided into multiple functional layers: substrate layer, optically variable layer, color constant layer, and holographic metallic layer. This segmentation allows each layer to contribute specific security functions while maintaining overall thread thinness and flexibility for easy document integration.
Solution Approach 2:
The patent extracts and separates the holographic function into a distinct metallic layer from the bulk holographic structure, allowing the thread to maintain thin profile while preserving security features. The optically variable layer is also separated to provide color-shifting effects without requiring thick material.
2Reliability
If conventional security threads are used, then basic security is provided, but they lack sophistication in design and flexibility
Solution Approach 1:
Different layers of the security thread possess distinct local properties: the optically variable layer provides angle-dependent color changes, the color constant layer maintains consistent appearance, and the holographic metallic layer adds reflective security features. This local differentiation enables sophisticated multi-layer security design while maintaining manufacturing flexibility.
3Illumination intensity
If conventional optically variable layers are used, then color shift effect is achieved, but the visual attractiveness and authentication capability are limited
Solution Approach 1:
The patent combines multiple optical effects in a single security thread structure: the optically variable layer provides color-shifting, the color constant layer provides stable reference colors, and the holographic metallic layer provides reflective patterns. This merging of functions enhances both visual attractiveness and authentication capability, making counterfeiting more difficult.
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 combination of layers in the security thread or stripe enhances security and visibility, making it more difficult to counterfeit by offering a range of visual effects and improved authentication capabilities, both visually and machine-readily.
Implementation Method 1
an optically variable layer (1) which changes color with viewing angle
Data Source
Figure 1~2
Figure 3A~3B
Figure 4A~5D
AI summary
An optically variable security thread or stripe (T) is provided which could be incorporated into or onto security documents. The security thread or stripe comprises: a) an optically variable layer (1), b) a color constant layer (2) having a color matching the color impression of the optically variable layer at a viewing angle, c) a holographic metallic layer (3) and d) a substrate (4), wherein the optically variable layer, the color constant layer and the holographic metallic layer are at least partially jointly visible from the side of the security thread or stripe comprising the optically variable layer and/or the color constant layer.