LED Wavelength Converting Material with Scatter for Brightness
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Solution Overview
Problem
Conventional light emitting diodes (LEDs) suffer from poor wavelength converting efficiency due to aggregation phenomena of yellow phosphors, which reduces brightness and light mixing efficiency, and existing solutions consume light, decreasing overall brightness.
Innovation Solution
A wavelength converting material comprising a wavelength converting activator and a scatter, where the activator emits light of one wavelength and the scatter scatters and can also emit light of another wavelength, with a bonding compound and transparent coatings to enhance activation and mixing, distributed in a transparent material to avoid total reflection and Fresnel loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If yellow phosphors are uniformly mixed in transparent material, then the structure appears homogeneous, but aggregation phenomenon occurs reducing wavelength converting efficiency
Solution Approach 1:
The patent divides the phosphor material into discrete particles suspended in transparent resin rather than attempting perfect uniform mixing. The phosphor particles are segmented and distributed throughout the encapsulant, allowing each particle to function independently as a wavelength converter while maintaining overall homogeneity at a macroscopic level.
Solution Approach 2:
The patent accepts local variations in phosphor distribution (aggregation at microscopic level) while maintaining overall uniformity at macroscopic level. The local aggregation of phosphor particles does not prevent individual particles from being activated by blue light, and the local quality of each phosphor particle remains functional for wavelength conversion.
2Stability of the object's composition
If scatter or air bubbles are doped in yellow phosphor encapsulant to uniformly mix blue and yellow light, then light mixing improves, but light quantity is consumed decreasing LED brightness
Solution Approach 1:
The patent removes the harmful scattering elements (air bubbles and excessive scatter dopants) from the encapsulant while retaining the essential function of light mixing through the inherent refractive index differences between phosphor particles and resin. This extraction of harmful scattering agents prevents light loss while maintaining adequate light uniformity.
Solution Approach 2:
The patent converts the potential harm of phosphor particle aggregation into a benefit by accepting that some local clustering is inevitable and even advantageous. The aggregated phosphor regions create localized scattering that aids light mixing without requiring additional scatter dopants that would consume light. The refractive index mismatch between phosphor particles and resin provides beneficial scattering.
3Quantity of substance
If phosphor particles are aggregated, then fewer particles are needed, but activation by blue light is blocked reducing efficiency
Solution Approach 1:
The patent uses an excessive amount of phosphor material to ensure that even with aggregation and shielding effects, sufficient phosphor particles remain accessible to blue light for activation. The overcompensation strategy ensures adequate wavelength conversion efficiency despite the shielding problem caused by aggregation.
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 increases the gap between activators, allowing for more efficient activation and uniform mixing of light, resulting in higher brightness and improved wavelength converting efficiency of LEDs.
Implementation Method 1
The wavelength converting activator 310 is suitable for being activated by a light with a wavelength λ1 so as to emit a light with a wavelength λ2
Implementation Method 2
The scatter 320 is disposed on the wavelength converting activator 310 and is suitable for scattering the light irradiated to a surface thereof
Data Source
AI summary
A wavelength converting material including a wavelength converting activator and a scatter is provided. The wavelength converting activator is suitable for being activated by a light with a wavelength λ1, so as to emit a light with a wavelength λ2. The scatter is disposed on the wavelength converting activator. The scatter is suitable for scattering a first light and a second light irradiated to a surface thereof. As a result of that the scatters on the wavelength converting activators increases the gap of two wavelength converting activators adjacent to each other, the wavelength converting activators could be sufficiently activated for emitting a light with wavelength λ2 while the wavelength converting materials are irradiated by the light with λ1. Therefore, the brightness of a light emitting diode with the wavelength converting material is enhanced.