Laser-Engraved Latent Image on Document Substrate

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Solution Overview

Problem

Existing methods for creating latent images on documents, such as hot stamping and intaglio printing, are energy-intensive and impractical for producing small or individually customized documents due to the need for printing plates.

Innovation Solution

A method using a laser-engravable document substrate that undergoes multiple laser treatments with varying energy densities to create raised elements with variable visibility, allowing for the formation of latent images without the need for printing plates, enabling quicker and cost-effective production of both small and large quantities of documents.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If hot stamping or intaglio print is used to create raised elements, then the latent image can be formed, but large energy consumption and long application time are required

Engineering Contradiction:
Improvelatent image qualityVSAvoidenergy consumption
Core Design Contradiction:
Manufacturing precisionVSUse of energy by moving object

Solution Approach 1:

The patent replaces traditional mechanical printing methods (hot stamping, intaglio printing) with laser beam technology. The laser beam directly engraves raised elements on the substrate without requiring mechanical pressure or heat transfer mechanisms, significantly reducing energy consumption and application time while maintaining latent image quality.

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

Solution Approach 2:

The patent uses variable energy density parameters of the laser beam to create different effects on the substrate. By adjusting the energy density, the laser can selectively raise certain areas to form the latent image while leaving other areas flat, enabling precise control over the latent image formation process.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If hot stamping or intaglio print is used to create raised elements, then the latent image can be formed, but the production of small number of documents or individually customized documents is impractical

Engineering Contradiction:
Improvelatent image qualityVSAvoidproduction flexibility
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent eliminates the requirement for physical printing plates by using laser beam direct engraving. This allows for rapid reconfiguration of the latent image pattern through software control, making it economically feasible to produce small batches or individually customized documents with the same quality as mass-produced documents.

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

Solution Approach 2:

The patent introduces dynamic control of the laser beam parameters (energy density, scanning speed, pattern) to adapt to different document requirements. This enables flexible production where the latent image can be customized for each document without requiring new physical plates, significantly improving manufacturing ease for small batches and personalized documents.

Inventive Principle:
Principle #15Dynamics

3Manufacturing precision

If traditional printing methods are used, then printing plates are required, but this increases device complexity and production cost

Engineering Contradiction:
Improvelatent image qualityVSAvoidprinting plate requirement
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the printing plate component from the traditional printing system. By using laser beam direct engraving, the system removes the need for physical plates entirely, simplifying the device structure and reducing costs while maintaining the ability to produce high-quality latent images.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent uses digital patterns as templates to guide the laser beam engraving process. Instead of physical plates, digital copies of the latent image design are used to control the laser, eliminating the need for physical plate manufacturing, storage, and handling while maintaining manufacturing precision.

Inventive Principle:
Principle #26Copying

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 approach allows for the efficient and cost-effective creation of personalized latent images on documents, facilitating the production of security documents like identity cards and tickets, while also enabling verification by both blind and sighted individuals.

Implementation Method 1

subjecting the document substrate to the laser beam to cause decomposition, increase of volume and carbonization of the substrate (100) to engrave the raised elements

Methodology Applied
Scientific EffectLaser beam heating: Laser

Implementation Method 2

subjecting the document substrate to the laser beam to cause decomposition, increase of volume and carbonization of the substrate (100)

Methodology Applied
Scientific EffectCarbonization: Pyrolysis

Implementation Method 3

subjecting the document substrate to the laser beam to cause decomposition, increase of volume and carbonization of the substrate (100)

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentEP2322355B1A method for making a latent image on a document substrate and a document substrate with a latent image
Publication Date: 2015.02.11 POLSKA WYTWORNIA PAPIEROW WARTOSCIOWYCH
  • EP2322355B1 patent drawingFigure 1~2
  • EP2322355B1 patent drawingFigure 3~4
  • EP2322355B1 patent drawingFigure 5~6

AI summary

A method for making a latent image (110) on a document substrate (100), comprising raised elements (120) forming image fragments (111,112) of variable visibility dependent on the viewing angle, wherein the method comprises the steps of providing a laser-engravable document substrate (100), and subjecting the document substrate (100) to a laser beam to engrave the raised elements (120). A document substrate (100) with a latent image, a security document comprising said document substrate, and a method for making said security document.