Tapered Wavelength Converter for High Lumen Density Light Source
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Solution Overview
Problem
Light source devices using LEDs face a dilemma where increasing the light-emitting area to achieve high brightness results in decreased illumination efficiency due to the etendue effect, leading to increased power consumption and device size, especially when using High Lumen Density (HLD) technologies with low light extraction efficiency.
Innovation Solution
A light source device incorporating a light-emitting body, a wavelength converter with a larger incident surface than emission surface, and a light collector with a reflective layer to improve light extraction efficiency by converting and focusing light into a smaller area, while maintaining low etendue, utilizing a scattering part to enhance diffusion and extraction of light.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the light-emitting area is increased to achieve high brightness, then the brightness is improved, but the illumination efficiency decreases due to increased etendue
Solution Approach 1:
The patent transitions from a conventional planar light-emitting structure to a three-dimensional tapered wavelength converter structure. The incident surface area is made larger than the emission surface area, creating a volumetric light conversion path that reduces etendue while maintaining high brightness output through the tapered geometry.
Solution Approach 2:
The patent changes the physical parameters of light conversion by using a wavelength converter with specific optical properties. The converter transforms light from a larger incident surface to a smaller emission surface, altering the spatial distribution parameters to reduce etendue while maintaining or enhancing illumination efficiency.
2Illumination intensity
If HLD technology is used to achieve high brightness without increasing etendue, then the brightness is improved, but the light extraction efficiency is low causing increased power consumption
Solution Approach 1:
The patent optimizes the optical parameters of the wavelength converter to improve light extraction efficiency. By carefully designing the incident and emission surface areas and the internal structure of the converter, the system achieves high brightness with reduced power consumption through improved light extraction.
Solution Approach 2:
The wavelength converter acts as an intermediary element between the light source and the output. It mediates the light transformation process, converting light from a larger incident surface to a smaller emission surface while improving extraction efficiency and reducing the need for additional cooling mechanisms.
3Illumination intensity
If HLD technology is used to achieve high brightness without increasing etendue, then the brightness is improved, but the device size increases due to additional cooling mechanisms
Solution Approach 1:
The patent changes the thermal management parameters by improving light extraction efficiency, which reduces heat generation. This allows the device to operate without additional cooling mechanisms, thereby maintaining high brightness while reducing overall device size.
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 achieves high brightness without increasing etendue, improving energy efficiency and reducing the need for cooling mechanisms, thereby miniaturizing the light source device.
Implementation Method 1
a technology referred to as so-called HLD (High Lumen Density) that realizes high brightness without increasing the etendue is proposed in JP-T-2016-521438, for example, by using a principle of fluorescent focusing that applies fluorescence conversion to light emitted by a plurality of LEDs
Implementation Method 2
the light collector includes a reflective layer configured to reflect the second wavelength range light entered by the light input part
Implementation Method 3
utilizing a scattering part to enhance diffusion and extraction of light
Data Source
AI summary
A light source device according to the present disclosure includes a light-emitting body configured to emit first wavelength range light, a wavelength converter that includes an incident surface on which the first wavelength range light is incident, and an emission surface configured to convert the first wavelength range light to second wavelength range light and subsequently emit, and for which the incident surface is set to be larger than the emission surface, a light collector including a light input part configured to enter the second wavelength range light, and a scattering part disposed on the emission surface of the wavelength converter or on a side closer to the light collector than the emission surface, wherein the light collector includes a reflective layer configured to reflect the second wavelength range light entered by the light input part.