Multilayer Data Medium Laser Marking via Segmented Layers
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Solution Overview
Problem
Existing methods for manufacturing multilayer data media, such as official documents, face challenges in ensuring high-quality, readable laser markings that are not compromised by optically variable effects, which often result in weakened or uneven laser markings due to interaction with interference pigments, making them difficult to decipher both by humans and reading devices.
Innovation Solution
The method involves varying the content and proportion of laser-sensitive agents in cover layers between optically variable effect and non-variable effect portions, allowing for homogeneous and contrasted laser markings that can be read across separations between these areas, ensuring excellent quality and security through careful layer arrangement and composition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If optically variable effect markings with interference pigments are applied to the data medium, then security is enhanced through optical variability, but laser marking quality deteriorates due to weakened and uneven markings that are difficult to decipher
Solution Approach 1:
The data medium is divided into multiple layers, with the optically variable effect marking placed on a first support and the laser-sensitive marking layer on a second support. This segmentation separates the two functional requirements, allowing each layer to perform its intended function without interfering with the other.
Solution Approach 2:
A separation layer is introduced between the optically variable effect marking and the laser-sensitive marking layer. This intermediary layer prevents the interference pigments from the optically variable marking from affecting the laser marking process, while still allowing the security features to be displayed when viewed from the front face.
2Reliability
If optically variable markings are placed over laser marking areas, then security is improved, but readability of laser markings deteriorates due to interaction with interference pigments
Solution Approach 1:
The solution moves the optically variable effect marking to a different spatial dimension by placing it on a separate support (first support) rather than directly over the laser marking area. The separation layer enables viewing of both the security marking and laser markings without mutual interference, effectively using the thickness dimension of the multilayer structure to resolve the conflict.
Solution Approach 2:
Different regions of the data medium are assigned different functional qualities: the first support carries the optically variable security marking for areas where security display is prioritized, while the second support carries the laser-sensitive marking layer for areas where personalization and readability are prioritized. The separation layer manages the transition between these different local qualities.
3Ease of manufacture
If a single layer contains both optically variable and laser-sensitive markings, then manufacturing is simplified, but laser marking uniformity deteriorates due to variable absorption by interference pigments
Solution Approach 1:
The marking functions are segmented into separate layers: the optically variable effect marking is applied to a first support while the laser-sensitive marking is applied to a second support. This segmentation eliminates the problem of variable laser absorption by interference pigments, ensuring uniform laser marking quality while maintaining the security benefits of optically variable effects.
Solution Approach 2:
The data medium employs a composite multilayer structure combining different materials with specific properties: a first support for optically variable markings, a separation layer to prevent interference, and a second support for laser-sensitive markings. This composite structure resolves the contradiction by allowing each material to perform its optimal function without compromising the other.
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 enables high-quality, readable laser markings that are not compromised by optically variable effects, enhancing security and maintaining consistent appearance across the data medium, even when partially covered by optically variable markings, thus improving the reliability and ease of personalization.
Implementation Method 1
capable of being marked by laser radiation applied to at least one outer face of this carrier
Implementation Method 2
it can be etched by laser radiation (partial ablation in thickness by vaporization as described for example by EP2407314)
Implementation Method 3
markings using iridescent and/or interference pigments
Implementation Method 4
markings using iridescent and/or interference pigments
Implementation Method 5
manufacturing a multilayer data carrier by hot-press lamination of a stack of a plurality of superimposed layers
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The invention relates to a method for manufacturing a multilayer data medium by hot lamination under pressure, capable of being marked by laser radiation applied to at least one outer surface (11) of said medium, in which at least one marking (13) with optically variable effect is arranged relative to a laser marking sub-layer such that said outer surface (11) has a portion with an optically variable effect optically stacked on at least one portion of the laser marking sub-layer and a portion (16) not comprising a marking with optically variable effect optically stacked on said at least one portion of the laser marking sub-layer. Said portions are produced with different contents of at least one marking agent that is sensitive to said laser radiation.