Low-Blue-Light Display Using Violet Pump and Spectral Filtering
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Solution Overview
Problem
Existing display technologies face challenges in achieving a blue-free emission while maintaining a good color gamut and efficiency, as blue radiation is crucial for exciting wavelength-converting materials and impacts the color gamut and human circadian cycle.
Innovation Solution
Incorporating a violet light source with blue-selective wavelength-converting materials, such as KSF phosphors, to emit a combination of violet and longer-wavelength light that mimics blue light perception, combined with quantum dots for enhanced efficiency and reduced toxic material loading.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If blue pump LEDs are used to excite wavelength-converting materials, then excitation efficiency is improved, but blue radiation harmful to human circadian cycle increases
Solution Approach 1:
The patent extracts and removes the harmful blue radiation component from the light source while retaining the useful excitation function. By using violet pump LEDs (peak wavelength 400-430 nm) instead of blue pump LEDs, the system eliminates blue radiation (450-495 nm) that harms circadian cycles while maintaining efficient excitation of wavelength-converting materials through the violet portion of the spectrum.
Solution Approach 2:
The patent changes the key parameter of pump LED peak wavelength from the conventional blue range (450-470 nm) to the violet range (400-430 nm). This parameter change fundamentally alters the spectral output, eliminating harmful blue radiation while preserving excitation efficiency for blue-selective wavelength-converting materials through their absorption characteristics in the violet range.
2Object-affected harmful factors
If blue radiation is absent, then circadian cycle impact is reduced, but color gamut performance deteriorates
Solution Approach 1:
The patent introduces blue-selective wavelength-converting materials as intermediaries that absorb violet pump light and convert it to blue emission. This intermediary mechanism allows the system to use violet pump LEDs (which lack harmful blue radiation) while still producing the blue light necessary for accurate color rendering and maintaining a wide color gamut, including DCI-P3 and Rec.2020 standards.
Solution Approach 2:
The patent employs composite material systems combining violet pump LEDs with blue-selective wavelength-converting materials (such as quantum dots, quantum rods, or phosphors). This composite approach enables the system to achieve both circadian-friendly operation and superior color gamut performance by integrating the advantages of violet emission with the color conversion properties of the wavelength-converting materials.
3Object-affected harmful factors
If violet pump LEDs are used, then blue-free emission is achieved, but manufacturing compatibility challenges increase
Solution Approach 1:
The patent applies dynamic design principles by making the violet pump LED and wavelength-converting material configuration adjustable and adaptable to different display form factors. The system can be optimized for various physical configurations including edge-lit, back-lit, and direct-lit displays, allowing manufacturers to integrate blue-free technology into existing display architectures with minimal structural changes.
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 achieves a blue-free display with a high color gamut, efficient performance, and compliance with regulatory standards by minimizing blue radiation and toxic material usage.
Implementation Method 1
a violet light source, wavelength-converting materials, such as KSF phosphors, to emit a combination of violet and longer-wavelength light that mimics blue light perception
Data Source
AI summary
A display for emitting display light comprising: (a) a light source for emitting a source light; and (b) a filter positioned in the path of said source light, said filter comprising at least short, medium and long filters, wherein said short filter is configured to transmit short-primary light from said source light, said short-primary light comprising a violet portion having wavelengths from 400 to 440 nm and at least a second portion having wavelengths above 440 nm such that said short-primary light is perceptually blue, said short-primary light having a short-primary SPD having a short-primary power between 380-780 nm and a blue power between 440-500 nm, wherein said blue power is less than 5% of said short-primary power.