Multi-layer Color Image Formation via Selective Wavelength Activation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for forming color images within multi-layer articles often result in images that are susceptible to scratches, stains, and tampering, and require protective lamination, which can compromise their durability and integrity.
Innovation Solution
The use of multi-layer articles comprising thermally activatable layers with light-to-heat convertor compositions and color-changing compounds, along with blocking layers, allows for the formation of color images within internal layers, providing enhanced resistance to damage and tampering without the need for external lamination. These layers are activated by specific wavelengths of light, enabling the creation of durable and fixed images.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If color images are formed on the surface of articles using traditional printing or thermal imaging techniques, then the images can be created with existing methods, but the images are susceptible to scratches, stains, and tampering, requiring protective lamination that compromises durability
Solution Approach 1:
The patent moves the color image formation from the surface dimension to the internal dimension of the article. Multiple thermally activatable layers are embedded within the interior of the article, with each layer containing color-changing compounds that activate at different temperatures. This internal positioning protects the images from surface-level damage while maintaining visibility through the article material.
Solution Approach 2:
The patent divides the color image formation into multiple separate thermally activatable layers, each responsible for different color components (e.g., cyan, magenta, yellow, black). Each layer has distinct absorption thresholds that allow selective activation. This segmentation enables independent control of each color layer and distributes the image formation process throughout the article's interior structure.
2Manufacturing precision
If multiple thermally activatable layers with different absorption thresholds are used to form color images, then selective activation of layers is achieved, but blocking layers must be inserted between layers to prevent unwanted activation
Solution Approach 1:
The patent applies local quality by giving each thermally activatable layer distinct optical properties, specifically different absorption thresholds at specific wavelengths. The first and third layers absorb light of a first wavelength, while the second and fourth layers absorb light of a second wavelength. This local differentiation in absorption characteristics allows selective activation of specific layers without requiring blocking layers, as each layer responds only to its designated wavelength.
3Reliability
If thermally activatable layers are positioned within the interior of articles, then images are protected from surface damage, but the layers must be precisely positioned to control light absorption and prevent cross-activation
Solution Approach 1:
The patent controls the activation behavior of each layer by adjusting key parameters: the absorption threshold of each thermally activatable layer and the wavelength of incident light. By tuning these parameters, the patent ensures that light at a specific wavelength activates only the intended layers while passing through or being reflected by other layers. This parameter-based control reduces dependency on precise physical positioning, allowing flexible internal layer arrangement while maintaining selective activation.
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 formation of durable, tamper-resistant color images within multi-layer articles, maintaining structural integrity and preventing unwanted activation of layers, thus enhancing the longevity and security of the images.
Implementation Method 1
the first thermally activatable layer comprises a first light to heat convertor composition and a first color changing compound, and wherein the light to heat convertor composition absorbs light of a first write wavelength
Implementation Method 2
a first blocking layer disposed between the first and second internal thermally activatable layers, the first blocking layer being adapted to at least partially block light of the first write wavelength
Implementation Method 3
the first thermally activatable layer comprises a first light to heat convertor composition and a first color changing compound
Data Source
AI summary
Multi-layer articles are described that are capable of forming color images. The articles include at least six layers, four thermally activatable layers (layers 1-4) and two blocking layers (layer 5 and 6). The layers are arranged such that layer 5 is disposed between layers 1 and 2 and layer 6 is disposed between layers 3 and 4. Thermally activatable layers 1 and 2 are activatable upon exposure to light of a first write wavelength, and blocking layer 5 is adapted to at least partially block light of the first write wavelength. Thermally activatable layers 3 and 4 are activatable upon exposure to light of a second write wavelength, and blocking layer 6 is adapted to at least partially block light of the second write wavelength. At least one, and possibly all of the thermally activatable layers include a light to heat convertor composition and a color changing compound. Some of the thermally activatable layers may be a group of layers arranged to selectively reflect light by constructive or destructive interference to provide a first reflective characteristic, the group of layers also having a first absorption characteristic suitable to, upon exposure to light comprising a write wavelength, absorptively heat the first group of layers by an amount sufficient to change the first reflective characteristic to a second reflective characteristic while maintaining the structural integrity of the group of layers.