Identification Document Angle-Dependent Image Reconstruction
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Solution Overview
Problem
Existing identification documents lack sufficient security against forgery while maintaining simplicity and cost-effectiveness in production.
Innovation Solution
The identification document features a carrier with a personalization area containing a recording layer with a black-and-white positive and negative image, and a partially transparent print layer with colour separation, allowing for a coloured identification image visible vertically and a coloured control image visible obliquely, enhancing security through angle-dependent image reconstruction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a lens arrangement with black-and-white positive and negative images is used, then forgery security is improved, but device complexity increases
Solution Approach 1:
The identification image is segmented into two distinct components: a black-and-white positive image and a black-and-white negative image, each encoded with different spatial frequencies and orientations. This segmentation allows each component to serve a specific security function while together they provide enhanced forgery protection through angle-dependent reconstruction.
Solution Approach 2:
The patent introduces a dimensional aspect by encoding images at different spatial frequencies and orientations that only reconstruct properly when viewed from specific angles. The positive and negative images are arranged in nested partial areas that require precise angular alignment to form the complete identification image, adding a dimensional security layer.
2Reliability
If angle-dependent image reconstruction is implemented, then forgery security is improved, but manufacturing precision requirements increase
Solution Approach 1:
The positive and negative images are pre-encoded with complementary spatial frequency characteristics during the manufacturing process. The nested arrangement of partial areas is predetermined to ensure that only at specific viewing angles will the images reconstruct properly, built-in during manufacturing rather than requiring post-production alignment.
Solution Approach 2:
The patent utilizes changes in spatial frequency parameters and orientation angles of the encoded images to create angle-dependent reconstruction. By varying these parameters in the positive and negative images, the system achieves security through physical encoding rather than requiring extremely tight manufacturing tolerances for alignment.
3Reliability
If both positive and negative images are encoded in the recording layer, then security against manipulation is improved, but production complexity increases
Solution Approach 1:
The patent merges the positive and negative images into a single recording layer structure with nested partial areas. Both images are encoded simultaneously in the same layer using laser modification, combining multiple security functions into one integrated component rather than requiring separate layers or components.
Solution Approach 2:
The recording layer serves multiple functions simultaneously: it stores both the positive and negative images, acts as the medium for laser modification, and provides the structural framework for angle-dependent reconstruction. This multi-functionality reduces production steps while enhancing security.
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 solution provides a high level of forgery security and attractive visual appearance by utilizing angle-dependent image reconstruction, making it difficult to manipulate the images without altering both the positive and negative components, thus significantly increasing the technical hurdle for counterfeiting.
Implementation Method 1
The laser-modifiable layer advantageously contains an infrared absorber, such as soot particles, which lead to local blackening of the recording layer when exposed to an IR laser, for example an Nd:YAG laser or a CO2 laser.
Implementation Method 2
the document blank is exposed to laser radiation from a vertical direction through the lens arrangement in order to introduce the black-and-white positive image into first partial areas of the recording layer
Data Source
AI summary
The invention relates to an identification document (10) for identifying a person with a coloured identification image (50) with a carrier (12) has a personalization area (14) for receiving image information, wherein the personalization area comprises a recording layer (20) for receiving first image information, a lens arrangement (22) for viewing the first image information, and a partially transparent print layer (26) formed on the lens arrangement for receiving second image information. The first image information contains a black-and-white positive image (54) of the person as a first partial image information and a black-and-white negative image (64) of the person as a second partial image information. The positive image (54) and the negative image (64) are each formed from a plurality of partial areas (30, 32) which are arranged in such a nested manner in the recording layer (20) that when viewed through the lens arrangement (22), the positive image (54) is only reconstructed in a substantially vertical viewing direction (36) and the negative image (64) is only reconstructed in a pre-determined, oblique viewing direction (36). The second image information of the partially transparent print layer (26) contains a colour separation (52) of the coloured identification image of the person, which is visible in both the vertical (34) and the oblique (36) viewing direction. When viewed vertically, the colour identification image (50) of the person is observable through an interaction of the black-and-white positive image (54) and the colour separation (52), and when viewed obliquely, a colour control image (60) is observable, which is formed through an interaction of the black-and-white negative image (64) and the colour separation (52).