Violet-Pumped Display Spectrum for Low Blue Light Color Gamut
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Solution Overview
Problem
Conventional LCD displays emit high levels of blue light, which can disrupt the human circadian cycle and negatively impact color gamut, making it challenging to create a display system that is both blue-free and maintains good color performance.
Innovation Solution
A display system that uses a violet light source combined with wavelength-converting materials and quantum dots to produce a blue-free emission, achieving a good color gamut by allowing violet and cyan or green light to combine and appear as blue, while minimizing blue radiation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If blue light is used to provide good color gamut and high efficiency, then color performance is improved, but circadian disruption increases
Solution Approach 1:
The patent extracts and removes the harmful blue light component (440-500nm) from the display spectrum while retaining violet light (380-440nm) and longer wavelength light. This is achieved through selective emission from the LED and quantum dot structure, eliminating the blue portion that causes circadian disruption while preserving color gamut through violet and cyan/green components
Solution Approach 2:
The patent changes the spectral parameters by using violet LEDs (380-440nm peak) instead of traditional blue LEDs (440-500nm peak), and by selecting quantum dots with specific emission wavelengths (cyan 470-520nm, green 520-560nm). This parameter change shifts the entire spectrum to avoid blue light while maintaining perceptual blue through violet-cyan combination
2Use of energy by moving object
If blue pump LEDs are used to excite wavelength-converting materials, then excitation efficiency is improved, but blue radiation increases
Solution Approach 1:
Instead of using blue pump LEDs to excite quantum dots (conventional approach), the patent inverts the approach by using violet pump LEDs (380-440nm) to excite quantum dots that emit cyan and green light. This inversion eliminates blue radiation from the pump source while maintaining efficient energy transfer and quantum dot excitation
Solution Approach 2:
The patent introduces violet light as an intermediary between the electrical energy source and the quantum dots. The violet LED serves as an intermediary pump source that transfers energy to quantum dots without directly emitting harmful blue light, acting as a mediator that achieves excitation efficiency while avoiding blue radiation
3Illumination intensity
If blue light is emitted for saturated blue perception, then color saturation is improved, but blue light content increases
Solution Approach 1:
The patent changes the color perception mechanism by combining violet light (380-440nm) with cyan light (470-520nm) to create perceptual blue without emitting blue wavelengths (440-500nm). The human visual system perceives this violet-cyan combination as saturated blue, achieving color saturation through color mixing rather than direct blue emission
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 system effectively reduces blue light emission, maintaining a high color gamut that matches standardized color gamuts like sRGB and DCI-P3, while ensuring low blue content in the display's output, thus minimizing circadian disruption.
Implementation Method 1
a violet light source combined with wavelength-converting materials and quantum dots to produce a blue-free emission
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.