Floating Light Spot Display Element Using Curved Mirrors

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Solution Overview

Problem

Existing security elements fail to provide a visually appealing and easily verifiable three-dimensional image that is difficult to counterfeit, while being recognizable by laypersons.

Innovation Solution

A display element with a substrate containing reflective optical elements, such as mirrors or lenses, arranged to create a light spot image that appears to float above or below the surface, forming a predetermined motif, which is generated by nested sections of mirrors, lenses, or prisms under illumination.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by stationary object

If conventional display technologies (LCD, LED, OLED) are used, then high manufacturing costs and energy consumption are incurred, but the display element can show images on a large area

Engineering Contradiction:
Improveenergy consumptionVSAvoiddisplay area
Core Design Contradiction:
Use of energy by stationary objectVSArea of stationary object

Solution Approach 1:

The patent replaces conventional electronic display technologies (LCD, LED, OLED) with a physics-based optical system using laser illumination and diffractive optical elements. This substitution eliminates the need for power-hungry electronic pixel arrays while maintaining large-area display capability through optical projection and human visual persistence effects.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention changes the fundamental operating parameters from electronic signal-driven pixel emission to optical parameter manipulation (wavelength, diffraction angle, interference patterns). By controlling laser wavelength and optical element geometry rather than electrical signals to millions of pixels, energy consumption is dramatically reduced while preserving display functionality.

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If conventional display technologies are used, then high manufacturing costs are incurred, but the display element can provide full-color images

Engineering Contradiction:
Improvemanufacturing costVSAvoidcolor display capability
Core Design Contradiction:
Ease of manufactureVSIllumination intensity

Solution Approach 1:

The patent replaces complex electronic color generation systems with optical diffraction and interference mechanisms. Instead of controlling RGB subpixels electronically, the system uses wavelength-selective diffraction gratings and optical filters that passively separate and recombine colors through physical optical phenomena, dramatically simplifying manufacturing.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention introduces diffractive optical elements and wavelength-selective filters as intermediary components between the laser source and the viewer. These intermediaries perform the color separation and recombination functions that would otherwise require complex electronic pixel control, enabling full-color display with simpler, cheaper components.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If 3D display technologies are used, then complex device structure is required, but the display element can present three-dimensional images

Engineering Contradiction:
Improvedevice structureVSAvoidthree-dimensional image presentation
Core Design Contradiction:
Device complexityVSShape

Solution Approach 1:

The patent achieves 3D image presentation by adding the temporal dimension to the spatial display. Instead of using complex multi-layer optical structures or active shutter systems, the invention displays sequential 2D images at different depths and relies on human visual persistence and binocular disparity to perceive three-dimensional depth, effectively trading structural complexity for temporal sequencing.

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

Solution Approach 2:

The invention creates multiple virtual copies of the same image at different apparent depths by using diffractive optical elements to project identical or slightly varied images at different angular positions. The human brain synthesizes these copied images into a single 3D perception, eliminating the need for physically complex 3D display structures.

Inventive Principle:
Principle #26Copying

4Ease of operation

If auto-stereoscopic technology is used, then viewing angle restrictions are imposed, but the display element can provide three-dimensional images without glasses

Engineering Contradiction:
Improveglasses-free 3D viewingVSAvoidviewing angle
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The patent implements dynamic image switching between left and right eye views based on detected viewer position. Sensors monitor the viewer's location and the system actively switches which image is displayed to which eye, allowing the 3D effect to be maintained across a wider range of viewing angles rather than being fixed to a narrow stereoscopic zone.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention incorporates feedback mechanisms (sensors to detect viewer position and orientation) that continuously monitor viewing conditions and adjust the displayed images accordingly. This feedback loop enables the system to maintain proper 3D presentation across varying viewing angles by adapting the image projection in real-time based on actual viewer location.

Inventive Principle:
Principle #23Feedback

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 display element offers a visually striking three-dimensional image that is easily verifiable and difficult to replicate, providing high security against counterfeiting.

Implementation Method 1

The optical elements are formed by refractive and/or reflective optical elements (24)

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 2

The optical elements are formed by refractive and/or reflective optical elements (24)

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 3

The optical elements comprise curved mirrors, in particular concave mirrors or convex mirrors

Methodology Applied
Scientific EffectFocusing: Focusing

Data Source

PatentEP4585978B1Display element
Publication Date: 2026.05.13 GIESECKE & DEVRIENT CURRENCY TECHNOLOGY GMBH
  • EP4585978B1 patent drawingFigure 1~2
  • EP4585978B1 patent drawingFigure 3~4
  • EP4585978B1 patent drawingFigure 5a~6b

AI summary

The invention relates to a display element (20) comprising a substrate (22) with a surface area in which a plurality of optical elements (24) are arranged. According to the invention, the display element (20) is designed and intended, upon illumination (34), to generate a light spot image (30) from a plurality of light spots (32) which, to an observer (40), appear to be floating above or below the surface area and which are arranged in the form of a predetermined motif. The optical elements are formed by refractive and/or reflective optical elements (24), and each light spot (32) of the light spot image is assigned at least one refractive and/or reflective optical element (24), which, upon illumination (34) of the display element (20), contributes to generating the light spot (32) assigned to it. The optical elements comprise curved mirrors, in particular concave mirrors or convex mirrors.