Lens Array Modifies Sub-Pixel Color Contribution for Secure Identity Documents
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current color image formation techniques in secure identity documents face challenges in producing highly saturated colors and achieving sufficient contrast, particularly when dealing with light or desaturated backgrounds, which limits their security and quality.
Innovation Solution
The use of an array of lenses interacting with a set of pixels to create shades of colors, where the lenses are configured to focus or diverge light on sub-pixels, allowing for the selection and modification of color contributions to generate highly saturated or desaturated zones, ensuring high security and quality while preventing unauthorized alteration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional color imaging techniques are used in identity documents, then security features can be implemented, but the color gamut and saturation are limited
Solution Approach 1:
The patent divides each pixel into multiple sub-pixels of different colors (e.g., red, green, blue, yellow, magenta, cyan) arranged in a specific pattern. This segmentation allows independent control of color contributions, enabling wide color gamut and high saturation while maintaining security features through the complex sub-pixel arrangement that is difficult to reproduce without authorization.
2Illumination intensity
If light or desaturated backgrounds are used in identity images, then visual comfort is improved, but contrast with the face area is insufficient
Solution Approach 1:
The patent applies different color saturation and brightness characteristics to different regions of the image. The background area uses desaturated or light colors for visual comfort, while the face area employs highly saturated colors for prominence. This local differentiation of color properties ensures both visual comfort and sufficient contrast through the sub-pixel arrangement and color selection in each region.
3Reliability
If complex security features are added to prevent fraud, then document security is improved, but the complexity of the imaging system increases
Solution Approach 1:
The patent merges security features directly into the color image formation process itself. The complex arrangement of sub-pixels within each pixel serves dual purposes: generating the desired color output and providing security against fraud. The specific sub-pixel patterns and color combinations act as inherent security features that are difficult to reproduce without authorization, eliminating the need for separate complex security imaging systems.
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 the creation of high-quality color images with a wide color gamut, ensuring secure and flexible personalization that can detect fraud, while maintaining excellent visual rendering and preventing unauthorized alteration.
Implementation Method 1
a lens array arranged opposite the set of pixels so as to generate the color image by focusing or divergence of incident light through the lenses onto at least some of the sub-pixels
Implementation Method 2
Each lens is positioned, relative to an associated pixel located opposite, to focus or diverge the incident light onto at least one of the sub-pixels of said associated pixel
Data Source
Figure 1~2
Figure 3A~3C
Figure 3D~4
AI summary
The invention relates to a document (2) capable of generating a colour image (6), comprising: a set of pixels (20) printed on or in a substrate (2), each pixel (20) forming a pattern comprising an arrangement of sub-pixels (22) of at least two different colours; and an array of lenses (LN) disposed facing the set of pixels so as to generate the colour image (6) by focusing or diverging an incident light through the lenses on at least one part of the sub-pixels (22), each lens (LN) being positioned, relative to an associated pixel (20) located opposite, to focus or diverge the incident light on at least one of the sub-pixels (22) of said associated pixel so as to modify the contribution of the respective colours of the sub-pixels (22) of the associated pixel (20), in a region of the colour image (6) generated through said lens, relative to the pattern intrinsically formed by the associated pixel (20) independently of said lens (LN).