Phosphor-Based UV Emitter for Filter-Free Safe Sterilization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional ultraviolet light sources, such as excimer lamps using KrCl gas, are toxic and require specialized facilities, have limited disinfection effectiveness due to narrow emission wavelengths, and often necessitate expensive optical filters to ensure safety, making them impractical for broad disinfection and sterilization applications.
Innovation Solution
A deep ultraviolet light irradiation device utilizing a broadband light source with a peak wavelength of 203±10 nm, employing borosilicate or quartz glass tubes and a phosphate-based phosphor layer, which emits ultraviolet light safely without the need for optical filters, while effectively disinfecting and minimizing harmful wavelengths for human exposure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If excimer lamps using KrCl gas are used to emit deep ultraviolet light at 222 nm, then virus inactivation effectiveness is improved, but the device becomes complex and requires specialized gas-proof facilities due to the high toxicity of krypton chloride gas
Solution Approach 1:
The patent extracts the harmful KrCl gas from the system and replaces it with a safer phosphor-based light source that emits similar deep ultraviolet wavelengths without requiring toxic gas handling facilities
Solution Approach 2:
The invention uses a solid-state phosphor layer that can be easily replaced if needed, eliminating the need for complex gas containment infrastructure and making the system more like a simple, replaceable component rather than a complex gas handling system
2Reliability
If excimer lamps with narrow emission wavelength at 222 nm are used, then virus inactivation at that specific wavelength is improved, but the adaptability to disinfect different kinds of bacteria and viruses is reduced
Solution Approach 1:
The patent changes the emission parameter from a narrow 222 nm peak to a broadband spectrum covering 200-280 nm, allowing effective disinfection across multiple wavelength ranges that different microorganisms are sensitive to
Solution Approach 2:
The broadband phosphor-based light source serves multiple disinfection functions simultaneously, covering UVC wavelengths effective against various bacteria, viruses, and fungi, making a single device adaptable to diverse disinfection needs
3Object-affected harmful factors
If conventional ultraviolet light sources are used to ensure safety by filtering harmful wavelengths, then human safety is improved, but the device complexity and cost increase due to expensive optical filters
Solution Approach 1:
The patent converts the potential harm of broad spectrum emission into a benefit by using the phosphor's natural emission characteristics to automatically limit harmful wavelengths below 200 nm and above 280 nm, turning the broadband nature from a safety risk into a disinfection advantage
Solution Approach 2:
The phosphor-based light source self-regulates its emission spectrum through the inherent properties of the phosphor material and glass tube, automatically providing safe wavelengths without requiring external filtering components
4Ease of manufacture
If glass tubes with limited ultraviolet transmission are used, then manufacturing ease is improved, but the transmission of deep ultraviolet light below 240 nm is reduced
Solution Approach 1:
The patent uses composite material construction with specific glass compositions (borosilicate or quartz) that combine manufacturability with enhanced deep ultraviolet transmission properties, achieving both ease of manufacture and high transmission efficiency
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 device achieves broad disinfection and sterilization capabilities comparable to existing technologies while reducing harmful ultraviolet radiation, ensuring safety without expensive filters and minimizing adverse human health effects.
Implementation Method 1
a xenon gas-containing discharge gas enclosed inside the glass tube and generating an electric discharge due to a voltage applied to the electrodes
Implementation Method 2
vacuum ultraviolet light with a peak wavelength of 173 nm generated by the electric discharge
Implementation Method 3
a phosphor layer formed on an inner surface of the glass tube and emitting light when excited by the electric discharge
Data Source
AI summary
The present invention provides a safe ultraviolet light irradiation device that uses ultraviolet light safe to the human body and has a wide range of microorganism elimination and sterilization effects, and also provides an ultraviolet light emitting element provided with: an electrode substrate having a pair of electrodes; at least one cylindrical or flattened cylindrical glass tube disposed on the electrode substrate so as to face both of the electrodes, the glass tube having both end parts sealed; a xenon gas-containing discharge gas enclosed inside the glass tube and generating an electric discharge due to a voltage applied to the electrodes; and a phosphor layer formed on an inner surface of the glass tube and emitting light when excited by the electric discharge, wherein the glass tube is made of borosilicate glass or quartz glass; and the phosphor layer is made of a phosphate-based fluorescent material and has an emission spectrum having a peak half value width within a wavelength range of 50 nm or less with a peak at a wavelength of 203±10 inm on an illuminance basis.