Covert Bar Code Using NIR Absorptive Reflective Materials
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional bar code technologies are ineffective in creating and decoding covert, invisible bar codes that can be detected and read in cluttered environments with low processor usage, and they lack the ability to be overlaid on existing visible text or graphics.
Innovation Solution
The development of covert bar codes using a combination of responsive absorptive and reflective materials that are activated by specific wavelengths of near-infrared (NIR) or ultraviolet (UV) light, allowing for robust detection and decoding, even in complex environments, and enabling overlay on existing visible matter.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional bar code technologies are used, then the bar codes are visible and can be read, but they cannot be covert or invisible and fail in cluttered environments
Solution Approach 1:
The patent applies color changes by using materials that change their optical properties based on illumination wavelength. The first material appears bright under first wavelength illumination while appearing dark under second wavelength illumination, enabling the covert bar code to be invisible in normal light but visible when illuminated with the specific activation wavelength, thus resolving the contradiction between visibility and covert operation in cluttered environments
Solution Approach 2:
The patent employs parameter changes by varying the illumination wavelength to activate the covert bar code. By changing the wavelength parameter of the light source to match the activation wavelength, the bar code transitions from invisible to visible state, improving detection reliability while maintaining covert properties under normal lighting conditions
2Measurement precision
If covert bar codes with multiple materials are used, then detection accuracy improves, but processor usage increases
Solution Approach 1:
The patent applies segmentation by dividing the bar code into distinct functional segments: a first portion with a first material that appears bright under first wavelength illumination, and a second portion with a second material that appears dark under the same illumination. This segmentation enables accurate detection of the bar code pattern while using simple binary contrast that reduces processor complexity for decoding
Solution Approach 2:
The patent extracts the essential detection function by using a single illumination wavelength that creates high contrast between the first and second materials. By taking out only the necessary material properties (bright appearance under specific wavelength) and eliminating unnecessary complexity, the system achieves high detection accuracy with reduced processor usage
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
Enables robust and efficient detection and decoding of bar codes with lower processor usage, even in cluttered environments, and allows for the bar codes to be overlaid on existing text or graphics, enhancing security and usability.
Implementation Method 1
The chemicals used for printing covert bar codes determine the wavelength of the light spectrum which excites the material
Implementation Method 2
The chemicals used for printing covert bar codes determine the wavelength of the light spectrum which excites the material, rendering the bar code visible for detection and decoding
Data Source
AI summary
Devices, methods, and systems for covert bar code pattern design and decoding are described herein. One covert bar code includes detector code and decoder code. The detector code includes a combination of responsive absorptive material and responsive reflective material, and the decoder code includes a combination of responsive absorptive material and responsive reflective material.