Light Source Apparatus with Concave Phosphor for High Efficiency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing light source apparatuses using reflective phosphors face challenges in improving light utilization efficiency while reducing optical density of excitation light, leading to decreased fluorescence conversion efficiency due to increased phosphor temperature and non-parallelized fluorescence emission.
Innovation Solution
A light source apparatus comprising a first light source section, a second light source section, polarization separators, a phase retarder, and a wavelength conversion layer with a concave lens, where the first light is focused via the side surfaces of the phosphor layer, and the second light is focused via the front surface, reducing optical density and enhancing fluorescence parallelization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If excitation light is incident on the phosphor via the front surface to enable cooling, then the fluorescence conversion efficiency decreases due to increased optical density, but if incident via the side surface to reduce optical density, then cooling becomes difficult
Solution Approach 1:
The phosphor layer is divided into multiple sections with different incident angles of excitation light. The front surface receives light at one angle while side surfaces receive light at different angles, allowing simultaneous optimization of cooling and conversion efficiency across different segments of the phosphor layer
Solution Approach 2:
Different regions of the phosphor layer are illuminated with excitation light at different angles optimized for their specific function: front surface regions are optimized for cooling while side surface regions are optimized for reducing optical density and improving conversion efficiency
2Productivity
If a reflective phosphor structure is used to reduce optical density, then the same optical system must serve both excitation and fluorescence collection, but this causes fluorescence to be non-parallelized and reduces utilization efficiency
Solution Approach 1:
The optical system is segmented into separate pathways: one optical system for incident excitation light and another for collecting fluorescence. This allows each optical system to be independently optimized for its specific function without compromise
Solution Approach 2:
A beam splitter or dichroic mirror is introduced as an intermediary element to separate the excitation light path from the fluorescence collection path, enabling independent optimization of both optical systems while maintaining a compact overall structure
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 effectively reduces temperature-related efficiency drops and improves fluorescence utilization by optimizing the excitation light distribution and emission path, resulting in enhanced light source performance.
Implementation Method 1
a wavelength conversion layer that converts the first light and the part of the second light into third light having a second wavelength band different from the first wavelength band
Implementation Method 2
a first polarization separator on which the first light outputted from the first light source section is incident and which reflects the first light
Implementation Method 3
a second polarization separator on which the second light outputted from the second light source section is incident and which reflects part of the second light and transmits another part of the second light
Implementation Method 4
a concave lens which is disposed between the first light source section and the first polarization separator and on which the first light outputted from the first light source section is incident
Implementation Method 5
a first light focusing optical system disposed between the wavelength conversion layer and the first polarization separator, wherein the first light is focused by the first light focusing optical system and enters the wavelength conversion layer
Data Source
AI summary
A light source apparatus according to an aspect of the present disclosure includes a first light source section, a second light source section, a first polarization separator, a second polarization separator that reflects part of second light and transmits the other part of the second light, a first phase retarder which is disposed between the first polarization separator and the second polarization separator and on which the part of the second light reflected off the second polarization separator is incident, a wavelength conversion layer that converts the first light and the part of the second light into third light having a second wavelength band and outputs the third light toward the first polarization separator, and a first light focusing optical system disposed between the wavelength conversion layer and the first polarization separator. The wavelength conversion layer has a first surface via which the third light exits and a second surface that intersects with the first surface. The first light is focused by the first light focusing optical system and enters the wavelength conversion layer at least via the second surface thereof, and the second light enters the wavelength conversion layer via the first surface thereof.