Violet LED Self-Cleaning Coating for Displays
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Photocatalytic coatings on LED-based displays are ineffective at night or in low sunlight conditions, such as cloudy days or vehicles with tinted windows, requiring expensive UV illuminators for activation.
Innovation Solution
Incorporating violet micro-LEDs into an array of red, green, and blue micro-LEDs to produce photons that initiate photo-catalysis, using a metal oxide or doped metal oxide photo-catalyst with a bandgap tuned to violet light, allowing activation by both UV radiation and violet light for self-cleaning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If photocatalytic coatings are used on LED-based displays, then self-cleaning functionality is provided, but the coating is ineffective at night or in low sunlight conditions
Solution Approach 1:
The patent changes the spectral parameter of the light source by incorporating violet LEDs (380-420nm) alongside standard RGB LEDs. This parameter change enables the photocatalytic coating to be activated not only by sunlight but also by artificial violet light, resolving the contradiction between maintaining self-cleaning reliability and adapting to various lighting conditions including nighttime and indoor environments.
Solution Approach 2:
The display system gains multi-functionality by integrating violet LEDs that serve dual purposes: maintaining display quality through invisible violet light emission and activating the photocatalytic coating for self-cleaning. This allows the same light source to perform both display and cleaning activation functions across different lighting conditions.
2Reliability
If UV illuminators are added to activate photocatalytic coating in low sunlight conditions, then self-cleaning effectiveness is improved, but device complexity and cost increase
Solution Approach 1:
The violet LEDs serve multiple functions: they maintain display quality by emitting invisible violet light and simultaneously activate the photocatalytic coating. This eliminates the need for separate UV illuminators, reducing device complexity while maintaining self-cleaning effectiveness across all lighting conditions.
Solution Approach 2:
The patent merges the display function and photocatalytic activation function into a single light source system. The violet LEDs are integrated into the display array, combining what would traditionally be separate components (display lights and UV illuminators) into one unified system.
3Reliability
If violet LEDs are added to the display array, then photocatalytic activation is enabled, but visibility of violet light may affect display quality
Solution Approach 1:
The patent utilizes the specific wavelength parameter of violet light (380-420nm) which is at the threshold of human visibility. By operating in this spectral range, the violet LEDs can activate the photocatalytic coating while remaining effectively invisible to the human eye, thus maintaining display quality while enabling photocatalytic 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
Enables self-cleaning of LED-based display surfaces in the absence of sunlight, reducing the need for additional UV illuminators and improving functionality in various lighting conditions.
Implementation Method 1
a photocatalytic coating disposed on the transparent material. The photocatalytic coating includes a photo-catalyst responsive to ultraviolet radiation present in sunlight and to the violet light emitted by the fourth LEDs
Implementation Method 2
a photo-catalyst responsive to ultraviolet radiation present in sunlight and to the violet light emitted by the fourth LEDs in the array of LEDs
Data Source
AI summary
A system includes a display. The display includes an array of LEDs covered by a transparent material. The array of LEDs includes a plurality of first, second, third, and fourth LEDs respectively configured to emit red, green, blue, and violet light. The red, green, and blue light from the first, second, and third LEDs is visible to human eye. Violet light from the fourth LEDs is invisible to human eye. The system includes a photocatalytic coating disposed on the transparent material. The photocatalytic coating includes a photo-catalyst responsive to ultraviolet radiation present in sunlight and to the violet light emitted by the fourth LEDs in the array of LEDs. The system includes a controller configured to selectively turn on the fourth LEDs to activate the photo-catalyst in the photocatalytic coating disposed on the transparent material.