Diffractive Microlens OVD for Bright 3D Contrast Inversion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing optical variable devices are thick, costly, and produce low-brightness magnified images with imperfect contrast inversion and parallax effects due to misalignment and inefficient light distribution.
Innovation Solution
A planar optical variable device with a micro-lens diffraction matrix and a micro-object matrix, where the micro-lenses have asymmetric triangular profiles and offset centers, modulated to ensure opposite optical powers and specific distances and angles, concentrating light diffracted in narrow angles for high brightness and contrast inversion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional optical variables are used in machine readable data carriers, then data encoding is achieved, but counterfeiting and copying become possible due to easy replication
Solution Approach 1:
The patent applies composite materials by integrating multiple functional layers including a pressure-sensitive dry adhesive layer, a releasable liner, and an optical variable material layer with specific properties. This multi-layer composite structure creates a security feature that is difficult to replicate while maintaining manufacturability through standardized lamination processes.
Solution Approach 2:
The optical variable material changes its optical parameters (color, reflectivity, or other optical properties) in response to applied stress or strain. This dynamic parameter change creates a security feature that requires precise control of material properties and manufacturing conditions, thereby increasing the difficulty of counterfeiting while remaining producible through controlled manufacturing processes.
2Reliability
If optical variable materials are integrated into labels or stickers, then security features are enhanced, but manufacturing complexity increases
Solution Approach 1:
The patent segments the security label into distinct functional layers: a pressure-sensitive dry adhesive layer, a releasable liner, and an optical variable material layer. This segmentation allows each layer to be manufactured and quality-tested separately before final assembly, reducing overall manufacturing complexity while maintaining security functionality.
Solution Approach 2:
The optical variable material layer serves multiple functions simultaneously: it provides security through optical variable properties, acts as a substrate for the adhesive layer, and enables stress detection through its optical response. This multi-functionality reduces the need for additional separate components, thereby managing device complexity.
3Reliability
If optical variables are made stress-sensitive for security applications, then counterfeiting resistance improves, but manufacturing precision requirements increase
Solution Approach 1:
The optical variable material is designed to change its optical parameters (such as color, reflectivity, or transmission) in response to applied stress or strain. This stress-induced parameter change provides a security feature that is difficult to counterfeit, as reproducing the precise optical response characteristics requires matching the original material's physical and optical properties.
Solution Approach 2:
The patent uses composite material structures where the optical variable material is integrated with adhesive and liner layers. This composite approach allows the optical properties to be optimized for security while the overall structure is designed for manufacturability, balancing the precision requirements with practical production capabilities.
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 device achieves a bright, magnified three-dimensional black-and-white image with full parallax and contrast inversion, suitable for security and decorative uses, while being thin and cost-effective to produce.
Implementation Method 1
The optical variable material is stress-sensitive and changes its optical properties in response to applied stress or strain
Data Source
Figure 1a~1c
Figure 2~3b
Figure 4a~4b
AI summary
The invention relates to an optical variable device forming a magnified three-dimensional image of a micro-object with full parallax and contrast inversion effects for protection of goods and documents. It includes a micro-lens diffraction matrix (2) with period P1, center O and at least two cells (5) containing a diffractive micro-lens L modulated by micro-object matrix (3) with period P2#P1 containing at least two micro-objects (4) including regions T1T2 said regions T1 T2 form regions M1, M2 in the micro-lens matrix containing micro-lenses L, L' with centers C, C'. The micro-lens and micro-object matrices have triangular asymmetric relief and (Formula (I). The micro-lenses L, L' have opposite signs of the optical power and/or the distance d, d' between two concentric protrusions of the corresponding micro-lenses L, L' at the boundary between two adjacent regions M1 M2 differ at least twofold, or angle φ between (Formula (II) and (Formula (III) is between 45° and 180°.