Lenticular Security Element With Two-Direction Optical Variability

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Solution Overview

Problem

Conventional lenticular security elements exhibit optical variability in only one direction of tilt, limiting their security and visual appeal.

Innovation Solution

A security element with an array of focussing elements that focus light in a first direction and overlapping image strips, featuring interlaced regions with different optically variable effect generating relief structures, allowing optical variability in two directions of tilt by varying relief structure parameters such as pitch, orientation, and size of the relief structure, and shape of the elements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional lenticular security elements are used, then they can display different images at different viewing angles, but they only exhibit optical variability in one direction of tilt

Engineering Contradiction:
Improveoptical variability directionsVSAvoidrelief structure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent extends optical variability from one dimension (single tilt direction) to two dimensions by incorporating relief structures with varying orientations. Image strips are assigned different relief structure orientations (e.g., 0° and 90°) to enable optical effects in orthogonal tilt directions, transforming a 1D optical effect into a 2D effect.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

Different regions of the security element are assigned different relief structure properties (orientation, pitch, shape) to achieve localized optical characteristics. Each image strip can have uniquely configured relief structures, allowing tailored optical responses in different areas and directions of the element.

Inventive Principle:
Principle #3Local quality

2Reliability

If conventional lenticular security elements are used, then they provide security features, but they are relatively easy to replicate with commonly available means

Engineering Contradiction:
Improvesecurity authenticityVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent employs multiple varying parameters in the relief structures including orientation angles, pitch dimensions, and shape configurations. These parameter variations create complex optical interference patterns that are difficult to replicate with standard copying equipment, thereby enhancing security while maintaining manufacturability through controlled parameter sets.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The security element combines multiple functional layers including image strips with embedded relief structures, overlying lenticular elements, and substrates. This composite structure integrates different optical functions (diffraction, refraction, interference) that work together to create authentication features resistant to counterfeiting.

Inventive Principle:
Principle #40Composite materials

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

Provides visually striking optical effects with multiple images and enhanced security by enabling optical variability in two directions, making it difficult to replicate accurately.

Implementation Method 1

an array of focussing elements that focus light in a first direction... the focussing elements are adapted to focus light only in the first direction

Methodology Applied
Scientific EffectLight focusing: Lens

Implementation Method 2

each of at least a first subset of the image strips of the first set of image strips comprises a first region having a first optically variable effect generating relief structure and a second region having a second optically variable effect generating relief structure such that the appearances of the first and second regions vary differently as the security element is rotated about the first direction

Methodology Applied
Scientific EffectDiffraction: Diffraction

Data Source

PatentEP3645300B2Security elements and methods of manufacture thereof
Publication Date: 2025.12.31 DE LA RUE INTERNATIONAL LTD
  • EP3645300B2 patent drawingFigure 1~2
  • EP3645300B2 patent drawingFigure 3A~3B
  • EP3645300B2 patent drawingFigure 4A~4B

AI summary

A security element is provided. The security element comprises an array of focussing elements defining a focussing element plane, each focussing element being adapted to focus light in a first direction, the focussing elements being arranged in a regular array along the first direction. An array of image strips is provided overlapping the array of focussing elements, the array of image strips comprising at least a first set of image strips and a second set of image strips, wherein the first and second sets of image strips are interlaced along the first direction, and wherein the first and second sets of image strips each have a periodicity along the first direction that is substantially the same as, or an integral multiple of, a periodicity of the array of focussing elements. The array of focussing elements and the array of image strips are arranged such that as the security element is rotated about a second direction, the second direction being the direction perpendicular to the first direction and within the focussing element plane, the first set of image strips is displayed via the array of focussing elements at a first viewing angle and the second set of image strips is displayed via the array of focussing elements at a second viewing angle. Each of at least a first subset of the image strips of the first set of image strips comprises a first region having a first optically variable effect generating relief structure and a second region having a second optically variable effect generating relief structure. The first optically variable effect generating relief structure differs from the second optically variable effect generating relief structure in at least one of the pitch of the relief structure, the orientation of the relief structure and the size, shape and/or profile of the elements of the relief structure such that the appearances of the first and second regions vary differently as the security element is rotated about the first direction.