Light Source Apparatus Fluorescence Leakage Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing light source apparatuses for projectors suffer from efficiency losses due to leakage of fluorescence that is not totally reflected at the interface between the wavelength conversion member and the air layer.
Innovation Solution
A light source apparatus comprising a first light source, a wavelength converter, a first light transmissive member, a first optical layer, and a first reflective member, where the wavelength converter has a surface for incident excitation light, and the first light transmissive member guides converted fluorescence, with the first optical layer transmitting excitation light and reflecting fluorescence, and the first reflective member reflecting both lights.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If fluorescence is totally reflected at the interface between the wavelength conversion member and air layer, then light extraction efficiency is improved, but components that are not totally reflected become leakage light and are lost
Solution Approach 1:
A light transmissive member with refractive index between that of the wavelength conversion member and air is introduced as an intermediary. This mediator reduces the refractive index difference at the interface, decreasing total internal reflection and allowing more fluorescence to escape without being lost as leakage light.
Solution Approach 2:
The refractive index parameter is changed by introducing the light transmissive member with a specific refractive index value that is intermediate between the wavelength conversion member and air. This parameter change optimizes the light extraction efficiency while minimizing energy loss.
2Productivity
If excitation light is incident on a large-area light incident surface of the wavelength conversion member, then fluorescence generation is improved, but the complexity of the optical system increases
Solution Approach 1:
The light transmissive member serves multiple functions: it acts as a window for light entry, provides a refractive index transition layer to reduce total internal reflection, and guides extracted light toward the optical system. This multi-functionality reduces the need for additional optical components, simplifying the overall system while maintaining high fluorescence generation efficiency.
3Reliability
If the refractive index difference between the wavelength conversion member and air is large, then total internal reflection is enhanced, but light extraction is hindered
Solution Approach 1:
The light transmissive member with intermediate refractive index acts as a mediator that bridges the large refractive index difference between the wavelength conversion member and air. This reduces total internal reflection losses while maintaining the structural integrity and optical performance of the system.
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 described configuration enhances the efficiency of light usage by minimizing leakage and optimizing the angular distribution of fluorescence, allowing it to be efficiently drawn out and used in projectors.
Implementation Method 1
a wavelength converter configured to convert the first light into second light within a second wavelength band different from the first wavelength band
Implementation Method 2
a first optical layer disposed between the first light source and the first light transmissive member and configured to transmit the first light and reflect the second light
Implementation Method 3
the generated fluorescence is totally reflected off the interface between the surface of the wavelength conversion member and the air layer, travels through the interior of the wavelength conversion member, and exits via the light exiting surface
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A light source apparatus includes a first light source emitting first light, a wavelength converter converting the first light into second light, a first light transmissive member guiding the second light, a first optical layer transmitting the first light and reflecting the second light, and a first reflective member reflecting the first light and the second light. The wavelength converter has a first surface on which the first light is incident via the first optical layer and the first light transmissive member. The first light transmissive member has a second surface that faces the first surface, and a third surface and a fourth surface that intersect with the second surface and face opposite sides. The third surface faces the first reflective member. The second light travels through an interior of the first light transmissive member and exits via the fourth surface.