Display Device Conversion Sheet Using Quantum Dots for Blue Light Shifting
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Solution Overview
Problem
Conventional blue light filters in display devices reduce luminance and cause significant color changes while attempting to minimize harmful blue light, leading to adverse health effects from prolonged exposure.
Innovation Solution
A display device incorporating a conversion sheet with alternately stacked conversion layers and blue light quantum dots and hollow scatterers that shift harmful blue light wavelengths to safer ranges without reducing luminance, using refractive index differences and geometric patterns to redirect light paths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a conventional blue light filter layer is used to minimize harmful blue light, then the harmful blue light is reduced, but the luminance of blue light is reduced and significant color change occurs
Solution Approach 1:
The patent applies parameter changes by using quantum dots with specific size ranges (2-10 nm) and composition ratios to precisely control the wavelength conversion of blue light. By adjusting the quantum dot parameters (size, material composition of CdSe, ZnS, and Mn), the system converts harmful blue light (415-455 nm) to safer wavelengths (460-480 nm) while maintaining luminance. The hollow scatterers with controlled size (1-5 μm) also modify light parameters through scattering effects, enhancing the wavelength shift without significant luminance loss.
Solution Approach 2:
The patent employs composite materials by combining quantum dots (CdSe, ZnS, Mn) with hollow scatterers in a gelatin matrix to create a conversion sheet. This composite structure enables simultaneous wavelength conversion and light scattering functions. The quantum dots convert harmful blue light wavelengths while the hollow scatterers redirect light paths, together achieving harmful blue light reduction while maintaining luminance and minimizing color change.
2Object-affected harmful factors
If a conventional blue light filter layer is used to minimize harmful blue light, then the harmful blue light is reduced, but significant color change occurs
Solution Approach 1:
The patent uses parameter changes by precisely controlling quantum dot size (2-10 nm) and material composition to achieve selective wavelength conversion. The quantum dots convert only the harmful blue light portion (415-455 nm) to safer wavelengths (460-480 nm) while preserving other visible spectrum wavelengths, thereby maintaining overall color characteristics. The gelatin matrix and hollow scatterers further refine this selective conversion process.
Solution Approach 2:
The patent applies local quality by using quantum dots with specific size and composition properties targeted at converting only harmful blue light wavelengths. The hollow scatterers are strategically designed with specific size ranges (1-5 μm) to scatter light in controlled patterns. This localized functional design ensures that only the harmful wavelength range is modified while other wavelengths pass through unchanged, preserving overall color fidelity.
3Object-affected harmful factors
If blue light quantum dots and hollow scatterers are used to shift blue light wavelengths, then harmful blue light is shifted to safer ranges, but device complexity increases
Solution Approach 1:
The patent merges multiple functions into a single conversion sheet component. The quantum dots perform wavelength conversion, the hollow scatterers perform light scattering, and the gelatin matrix provides structural support and uniform distribution. This consolidation of wavelength conversion, scattering, and structural functions into one integrated sheet reduces overall device complexity compared to using separate layers for each function.
Solution Approach 2:
The conversion sheet achieves multi-functionality by simultaneously performing wavelength conversion (quantum dots), light scattering (hollow scatterers), and structural support (gelatin matrix) in a single component. This universal design eliminates the need for multiple separate functional layers, simplifying the overall device structure while achieving harmful blue light reduction and luminance maintenance.
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
Effectively shifts harmful blue light wavelengths to safer ranges while maintaining brightness and preventing luminance loss, thus reducing health risks associated with prolonged exposure.
Implementation Method 1
blue light quantum dots capable of shifting blue light harmful to humans to blue light not harmful to humans
Implementation Method 2
hollow scatterers capable of shifting blue light harmful to humans to blue light not harmful to humans
Implementation Method 3
the at least one conversion pattern includes alternately stacked at least one first conversion layer having a first refractive index and at least one second conversion layer having a second refractive index different from the first refractive index
Data Source
AI summary
A display device includes a display panel, a backlight unit supplying light to the display panel, and a conversion sheet located between the backlight unit and the display panel. The conversion sheet includes at least one conversion pattern. A top portion of the at least one conversion pattern has a greater area than a bottom portion the at least one conversion pattern. The at least one conversion pattern includes alternately stacked at least one first conversion layer having a first refractive index and at least one second conversion layer having a second refractive index different from the first refractive index.