Wavelength Conversion Element with Partial Binder Coverage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing wavelength conversion elements suffer from reduced efficiency due to increased exit area of fluorescence, leading to decreased incident efficiency in optical systems, and backward scattering of excitation light, which decreases wavelength conversion efficiency as the intensity of excitation light increases.
Innovation Solution
A wavelength conversion element with a phosphor layer having phosphor particles bound by a binder that includes glass, where the binder binds only a part of the surface of each phosphor particle, and an antireflection layer is disposed on the incident side of the excitation light to reduce reflection and enhance light entry, with a glass content rate between 0 vol% and 10 vol% to optimize light collection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the entire surface of phosphor particles is covered with binder, then the phosphor particles are well bound together, but the exit area of fluorescence increases and incident efficiency to the optical system decreases
Solution Approach 1:
The patent applies local quality by making the binder coverage non-uniform across the phosphor particle surfaces. Specifically, the binder is designed to cover only a portion of each phosphor particle surface rather than the entire surface, creating areas with different optical properties. This localized binder application maintains sufficient mechanical binding between particles while reducing the overall exit area of fluorescence, thereby improving incident efficiency to the optical system.
2Illumination intensity
If the intensity of excitation light is increased, then the brightness of fluorescence is improved, but backward scattering of excitation light increases and wavelength conversion efficiency decreases
Solution Approach 1:
The patent converts the harmful backward scattering effect into a beneficial one by strategically positioning the binder on the incident side of the phosphor particles. The binder layers on the excitation light incident side act to reflect or scatter the backward-scattered excitation light back into the phosphor particles, giving the excitation light another chance to be absorbed and converted to fluorescence. This transforms the harmful backward scattering into an additional opportunity for wavelength conversion, thereby maintaining or improving conversion efficiency even at high excitation light intensities.
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
This configuration enhances the brightness and optical system efficiency by minimizing the spread of fluorescence and reducing backward scattering, thereby increasing the intensity of emitted fluorescence and improving wavelength conversion efficiency.
Implementation Method 1
a wavelength conversion element which is excited by excitation light entering the wavelength conversion element to emit fluorescence having longer wavelength than the wavelength of the excitation light
Implementation Method 2
an antireflection layer disposed on an incident side of the excitation light with respect to the phosphor layer
Data Source
AI summary
The wavelength conversion element includes a phosphor layer having a plurality of phosphor particles and a binder configured to bind one of the phosphor particles adjacent to each other and another of the phosphor particles adjacent to each other out of the plurality of phosphor particles, an antireflection layer disposed on an incident side of the excitation light with respect to the phosphor layer, and a substrate provided with the phosphor layer, wherein the binder includes glass, and the binder binds a part of a surface of the one of the phosphor particles and a part of a surface of the another of the phosphor particles to each other.