Holographic Color Image Modulation for Secure Sub-Pixel Rendering
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing color image formation techniques in secure documents suffer from limited color gamut, poor positioning accuracy, and irregularities in sub-pixel printing, leading to degraded image quality and vulnerability to falsification.
Innovation Solution
A holographic structure forming an arrangement of pixels with color modulation means that modify the colorimetric contribution of sub-pixels to create secure and high-quality color images by diffraction, reflection, and refraction, using laser ablation and optical amplification to enhance saturation and brightness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional printing methods are used to print colored sub-pixels, then the manufacturing process is simple and easy to implement, but the positioning accuracy is poor and the lines of sub-pixels are irregular, leading to degraded color rendering
Solution Approach 1:
The patent replaces conventional mechanical printing methods with a holographic approach. A hologram is recorded that, when illuminated, generates an arrangement of pixels through optical diffraction and interference patterns. This substitution of mechanical printing with optical field-based pixel generation achieves precise sub-pixel positioning without the limitations of printing machine accuracy, eliminating irregularities in sub-pixel lines and enabling superior color rendering.
2Manufacturing precision
If white areas are added between sub-pixels to compensate for positioning inaccuracies, then the positioning tolerance is increased, but the color saturation is reduced and the color gamut is limited
Solution Approach 1:
The holographic pixel generation method eliminates the need for white separator areas between sub-pixels. Since pixels are generated optically through diffraction and interference rather than mechanically printed, achieving precise positioning with sub-micron accuracy, adjacent sub-pixels of different colors can be placed directly next to each other without overlapping. This enables full color saturation and maximum color gamut while maintaining positioning tolerance.
3Reliability
If conventional printing is used to create color images, then the process is straightforward and easy to manufacture, but the security against falsification is insufficient
Solution Approach 1:
The patent replaces conventional printing with holographic recording and optical field generation. The hologram is recorded during manufacturing with precise control over the optical fields that will generate the pixel arrangement. During authentication, the generated pixel arrangement can be verified for correctness, providing security against falsification. This approach maintains manufacturing simplicity while adding a verifiable security layer that is difficult to counterfeit.
4Reliability
If laser carbonization is used to create grayscale levels in a laser-etched layer, then the security against falsification is improved, but the color gamut and image brightness are limited
Solution Approach 1:
The patent replaces laser carbonization with direct optical field generation through holographic diffraction. The hologram, when illuminated by a light source, generates an arrangement of pixels where each pixel comprises multiple colored sub-pixels. The color and brightness of each sub-pixel are determined by the optical interference pattern, enabling full color gamut and high image brightness without the limitations of carbonized grayscale layers.
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 solution enables the production of secure, high-quality color images resistant to falsification with improved color saturation and brightness, overcoming limitations of conventional printing methods.
Implementation Method 1
a holographic structure forming an arrangement of pixels from which a color image is formed
Implementation Method 2
color modulation means configured to modify a colorimetric contribution of the sub-pixels to each other
Data Source
Figure 1~2
Figure 3~4
Figure 5~6B
AI summary
The invention relates to a colour image (IG) comprising: a first layer (10) comprising a holographic structure forming an arrangement (29) of pixels (30) each comprising sub-pixels (32) of distinct colours; and colour modulation means configured to select the colour of the pixels (30) by modifying the colorimetric contribution of the sub-pixels (32) relative to each other in the pixels (30) so as to reveal a personalised colour image. The colour modulation means can comprise: regions of the holographic structure, called destroyed regions, that are locally destroyed by a laser; masking means positioned facing the arrangement of pixels to locally mask all or some of the sub-pixels; or even amplification means positioned facing the arrangement of pixels to locally amplify the luminosity of all or some of the sub-pixels.