Near-Infrared Luminescent Material for Security Ink Detection
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Solution Overview
Problem
Existing luminescent materials are not effectively excited by infrared or near-infrared rays, leading to challenges in forgery prevention and detection, particularly in security documents, and there is a need for a low-cost, detection-sensitive material that can emit infrared or near-infrared light for use in commercial LED light sources and silicon/InGaAs detectors.
Innovation Solution
A luminescent material expressed by the chemical formula Yb a Y x V y Si z O 4 : M, where 0 < a ≤ 1, 0 < X ≤ 1, 0 < Y ≤ 1, 0 < Z ≤ 1, and M is Nd 3+ or Er 3+, is excited by near-infrared rays, and is incorporated into security inks and printed materials to prevent forgery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a luminescent material is excited by a blue light source, then the material can be excited, but the blue light source cannot penetrate through tissue and bone effectively
Solution Approach 1:
The patent introduces a near-infrared luminescent material as an intermediary system. The near-infrared light source excites this material, which then emits blue light to excite the actual luminescent particles. This mediator approach allows the excitation light to penetrate tissue and bone effectively while still achieving the desired excitation of the luminescent material.
Solution Approach 2:
The patent changes the excitation light wavelength parameter from blue light to near-infrared light. This parameter change enables the excitation light to penetrate tissue and bone more effectively, as near-infrared light has better penetration properties compared to blue light, while still allowing the luminescent material to be excited and emit the required blue light.
2Object-affected harmful factors
If a near-infrared light source is used to excite the luminescent material, then the light can penetrate tissue and bone, but the luminescent material must be specifically designed to respond to near-infrared excitation
Solution Approach 1:
The patent employs composite materials by combining a near-infrared luminescent material with a blue light-emitting luminescent material. The near-infrared luminescent material absorbs near-infrared light and converts it to blue light, which then excites the blue light-emitting luminescent material. This composite approach allows the system to benefit from both the penetration capability of near-infrared light and the effective excitation of the luminescent material.
3Adaptability or versatility
If conventional luminescent materials are used, then they can be excited by blue light, but they cannot be excited by near-infrared light
Solution Approach 1:
The patent creates a universal excitation system by using a near-infrared light source that can excite the near-infrared luminescent material, which in turn excites the blue light-emitting luminescent material. This multi-functional approach allows the system to work with a single near-infrared light source for both penetration and excitation purposes, enhancing the adaptability and reliability of the luminescent material system.
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 material emits near-infrared light, enabling low-cost forgery prevention and detection using commercial LEDs and sensitive detectors, suitable for security documents and printed materials.
Implementation Method 1
a near-infrared luminescent material which has a maximum absorption wavelength of 900 nm or more and emits blue light having a maximum emission wavelength of 450 nm or less
Data Source
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AI summary
The present invention relate generally to near infrared luminescent material excited by near infrared ray and method of manufacturing the same, and to be more specific, the method comprising: a) mixing, as host material, a compound including ytterbium salt, yttrium salt, silicon salt and vanadium salt or a compound including ytterbium, yttrium oxide, silicon dioxide and vanadium oxide with one or more species of a lanthan metal oxide selected from a group comprising Nd 3+ and Er 3+ as an activation agent (M) or metal, or proceeding without an activation agent; b) increasing the temperature of compounds obtained from a) step and heat-treating at 900 ~ 1100 ℃ to manufacture a luminescent powder; and c) crushing the luminescent powder using a crusher.