Projector Light Source Air Layer Fluorescence Extraction
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Solution Overview
Problem
The existing light source devices in projectors using fluorescence from phosphors suffer from efficiency losses due to fluorescence leakage at the interface between the wavelength conversion member and air, as components entering at angles less than the critical angle are not totally reflected and escape before reaching the emission surface.
Innovation Solution
A light source device configuration with a first optical member to transmit excitation light and reflect fluorescence, a reflective member to reflect both light types, and an air layer between these components, allowing fluorescence to propagate through the air layer and be emitted from a specific surface, reducing losses and enhancing efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If fluorescence propagates through the wavelength conversion member to reach the emission surface, then the light extraction efficiency is improved, but fluorescence leaks at the interface between the wavelength conversion member and air, reducing use efficiency
Solution Approach 1:
The patent introduces an optical member as an intermediary between the wavelength conversion member and the external environment. This optical member has a refractive index that is optimized to match the wavelength conversion member, thereby reducing refraction and reflection losses at the interface. The optical member acts as a mediator that allows fluorescence to be extracted efficiently while preventing leakage, thus resolving the contradiction between light extraction efficiency and fluorescence loss.
2Illumination intensity
If the emission surface area is reduced to concentrate fluorescence, then the light intensity is improved, but the total amount of extracted fluorescence is reduced
Solution Approach 1:
The patent utilizes the third dimension (depth) by optimizing the thickness of the wavelength conversion member and the position of the emission surface. By carefully controlling the thickness, the patent ensures that fluorescence generated throughout the volume of the wavelength conversion member can be effectively extracted through the emission surface. This dimensional optimization allows both high light intensity and sufficient total fluorescence extraction to be achieved simultaneously.
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 proposed configuration minimizes fluorescence loss and improves the overall efficiency of light utilization in the projector by effectively guiding fluorescence through an air layer, thereby increasing the use efficiency of the emitted light.
Implementation Method 1
a first optical member disposed between the first light source and the wavelength conversion element and configured to transmit the first light
Implementation Method 2
a first optical member disposed between the first light source and the wavelength conversion element and configured to transmit the first light and reflect the second light
Implementation Method 3
a first reflective member configured to reflect the first light and the second light
Implementation Method 4
a wavelength conversion element configured to convert the first light into second light in a second wavelength band different from the first wavelength band
Implementation Method 5
using fluorescence emitted from a phosphor when the phosphor is irradiated with excitation light emitted from a light emitting element
Implementation Method 6
the fluorescence generated inside the wavelength conversion member is totally reflected at an interface between the surface of the wavelength conversion member and an air layer to thereby propagate inside the wavelength conversion element
Data Source
AI summary
A light source device includes a first light source configured to emit first light, a wavelength conversion element configured to convert the first light into second light, a first optical member that is disposed between the first light source and the wavelength conversion element and is configured to transmit the first light and reflect the second light, and a first reflective member configured to reflect the first light and the second light. A first air layer is disposed between the first optical member and the wavelength conversion element. The wavelength conversion element includes a first surface on which the first light is incident via the first optical member and the first air layer, a second surface facing to an opposite side to the first surface, and a third surface and a fourth surface crossing the first surface and the second surface and facing to respective sides opposite to each other. The first reflective member is disposed in a region at the third surface side of the first air layer. The second light emitted from the first surface of the wavelength conversion element propagates through the first air layer and is emitted from a region at the fourth surface side of the first air layer.