Wavelength Conversion Layer With Dual Phosphors For Display Brightness
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Solution Overview
Problem
Current display devices face limitations in improving brightness, photo-conversion efficiency, and contrast due to inefficiencies in light emission from light sources, particularly with high power sources like blue light emitting diodes, which experience heat generation and efficiency variations.
Innovation Solution
A display device incorporating a light source with a wavelength conversion layer containing at least two phosphors, an unsaturated phosphor for consistent efficiency and a saturated phosphor for high brightness, which absorbs and converts light into a second wavelength band, ensuring stable brightness and color coordinates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If high power light emitting diodes are used to increase brightness, then luminous output is improved, but heat generation and efficiency variations occur
Solution Approach 1:
The patent applies parameter changes by utilizing phosphors with different saturation characteristics (saturated and unsaturated phosphors) to convert light wavelengths. This chemical/physical parameter change enables efficient light conversion while managing heat generation, as the phosphor materials transform high-energy blue light into lower-energy visible light wavelengths, reducing thermal load on the system.
Solution Approach 2:
The patent employs photoluminescence phase transition in phosphor materials, where absorbed light energy is converted to emitted light at different wavelengths. The saturated phosphor undergoes efficient energy conversion at high excitation levels, while the unsaturated phosphor maintains stability, together managing the phase transition process to reduce heat accumulation while maintaining brightness.
2Illumination intensity
If high power light emitting diodes are used to increase brightness, then luminous output is improved, but photo-conversion efficiency varies
Solution Approach 1:
The patent segments the wavelength conversion function into two distinct phosphor components: a saturated phosphor for high efficiency conversion and an unsaturated phosphor for stability. This segmentation allows each phosphor to operate in its optimal efficiency range, with the saturated phosphor handling high-intensity conversion and the unsaturated phosphor providing consistent performance, thereby reducing overall energy loss and efficiency variation.
Solution Approach 2:
The patent creates a composite phosphor system combining saturated and unsaturated phosphors with different photoluminescence characteristics. This composite material approach leverages the strengths of each phosphor type, achieving high photo-conversion efficiency while maintaining stability across varying operating conditions, thus minimizing energy loss and efficiency variation.
3Device complexity
If single phosphor wavelength conversion is used, then device complexity is low, but light emitting efficiency is limited
Solution Approach 1:
The patent merges the functions of saturated and unsaturated phosphors into a single integrated wavelength conversion layer. This combining approach maintains relatively simple device structure while achieving superior light emitting efficiency, as the two phosphors work synergistically to convert light wavelengths with minimal energy loss, overcoming the limitations of single-phosphor systems.
Solution Approach 2:
The dual-phosphor wavelength conversion layer performs multiple functions simultaneously: the saturated phosphor provides high-efficiency wavelength conversion, while the unsaturated phosphor ensures operational stability and consistency. This multi-functionality is achieved within a single conversion layer, maintaining device simplicity while maximizing light emitting efficiency and minimizing energy loss.
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 significantly increases photon emission efficiency while minimizing heat-related issues, achieving optimized brightness and color quality by maintaining consistent luminous flux across varying currents and temperatures, thus enhancing display performance.
Implementation Method 1
a wavelength conversion layer disposed on the light emitting device, at least partially absorbing the light having a first wavelength band, converting the absorbed light into a second wavelength band
Data Source
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AI summary
A display device is disclosed. Particularly, a display device including a wavelength conversion layer is disclosed. The display device includes a first light source including a substrate, a light emitting device disposed on the substrate and emitting light having a first wavelength band, and a wavelength conversion layer disposed on the light emitting device, at least partially absorbing the light having a first wavelength band, converting the absorbed light into a second wavelength band, and including at least two phosphors emitting substantially the same color.