Light Source Unit with Dual Intensity Distributions for Adaptive Illuminance
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Solution Overview
Problem
Existing light source devices using phosphors struggle to achieve desired illuminance distributions, particularly in applications requiring adaptive lighting like vehicle headlights, where switching between low and high beams is necessary, due to limitations in controlling light intensity and distribution.
Innovation Solution
A light source unit comprising a phosphor, a condenser lens, and two light source parts that emit excitation light with different intensity distributions, allowing for the generation of white light with adjustable illuminance by varying the divergence angles of the excitation light, which is then spatially modulated to achieve desired illuminance patterns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a single light source is used to illuminate the phosphor, then the device structure is simple, but the illuminance distribution cannot be switched between different patterns (low beam and high beam)
Solution Approach 1:
The single light source is segmented into two separate light sources (first light source and second light source), each capable of producing different light intensity distributions. This segmentation enables the system to switch between different illuminance patterns (low beam and high beam) by selectively activating different light sources, while keeping the overall device structure relatively simple.
2Manufacturing precision
If collimated light is used to illuminate the phosphor, then the optical path is simple, but the light intensity distribution on the phosphor cannot be effectively controlled
Solution Approach 1:
Instead of using uniform collimated light, the patent employs light sources that produce different local intensity distributions (first light intensity distribution and second light intensity distribution) on the phosphor. This local quality variation allows effective control over the illuminance pattern, enabling the system to generate different beam patterns (low beam with wider distribution and high beam with concentrated distribution) by selecting appropriate light sources.
3Adaptability or versatility
If the light source emits light in multiple directions, then the illuminance distribution can be adjusted, but light loss increases due to divergence
Solution Approach 1:
The patent uses light sources with different emission characteristics (different divergence angles and intensity distributions) that can be dynamically selected based on the required illuminance pattern. By switching between light sources optimized for specific patterns (e.g., a light source with smaller divergence angle for high beam to reduce light loss, and another with larger divergence for low beam), the system achieves adaptable illuminance distribution while minimizing energy loss for each operating mode.
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
Enables efficient generation of light with specific illuminance distributions suitable for both low and high beam modes, reducing light loss and allowing for compact device design while maintaining high light intensity, thus addressing the limitations of existing technologies.
Implementation Method 1
a phosphor that emits fluorescent light, based on first excitation light and second excitation light
Implementation Method 2
a condenser lens that condenses the first excitation light and the second excitation light on the phosphor
Data Source
AI summary
A light source unit according to an aspect of the present disclosure includes: a phosphor; a condenser lens; a first light source part; and a second light source part. The phosphor emits fluorescent light based on first excitation light and second excitation light. The condenser lens condenses the first excitation light and the second excitation light on the phosphor. The first light source part emits the first excitation light such that the first excitation light forms a first light intensity distribution on the phosphor. The second light source part emits the second excitation light such that the second excitation light forms a second light intensity distribution different from the first light intensity distribution, on the phosphor.