Color Conversion Element Absorbing Portion for Laser Safety
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Solution Overview
Problem
The emission of laser light with high directivity from a lighting device is undesirable as it can affect the human body, especially when the phosphor layer is peeled off from the substrate without being converted into white light.
Innovation Solution
A color conversion element is designed with a phosphor layer stacked above a substrate, incorporating a reflecting layer and an absorbing portion. The absorbing portion is positioned above the substrate and covered by a joining portion, which fractures and exposes the absorbing portion when the phosphor layer is peeled off, allowing it to absorb the laser light and prevent its emission. Additionally, a temperature detecting unit monitors the substrate's temperature to control the emission of laser light.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a phosphor layer is stacked above a substrate with a reflecting layer to convert laser light to white light, then white light emission is achieved, but laser light may be emitted directly to the outside without conversion if the phosphor layer is peeled off
Solution Approach 1:
The invention divides the protective function into two segments: the phosphor layer for normal white light conversion, and a separate absorbing layer positioned at the substrate side that activates only when the phosphor layer is removed. This segmentation allows the system to maintain normal functionality while providing targeted protection against the specific hazard of laser light leakage.
Solution Approach 2:
The absorbing layer is pre-positioned below the substrate, covered by both the substrate and phosphor layer during normal operation. This preliminary placement ensures that when the phosphor layer is peeled off, the absorbing layer is already in position to immediately absorb any leaked laser light, providing automatic protection without requiring additional activation steps.
2Object-affected harmful factors
If an absorbing portion is added below the substrate to absorb leaked laser light, then safety is improved, but device complexity increases
Solution Approach 1:
The substrate serves multiple functions: it provides structural support for the phosphor layer, acts as a barrier during normal operation, and works in conjunction with the absorbing layer to provide safety protection. The absorbing layer itself is designed to be simple in structure while providing the critical safety function, avoiding unnecessary complexity in the overall device architecture.
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
This configuration effectively reduces the emission of laser light to the outside even when the phosphor layer is peeled off, ensuring safety by absorbing the laser light and notifying any abnormalities through controlled emission cessation.
Implementation Method 1
an absorbing portion (45) which is covered with the joining portion (42) and absorbs laser light
Implementation Method 2
another portion of the laser light that does not directly shine on the phosphor particles is reflected by the reflecting layer and shines on the phosphor particles
Implementation Method 3
The phosphor particles convert the laser light that has reached the phosphor particles into white light and emit the white light
Data Source
Figure 1~4
Figure 5~8
Figure 9
AI summary
A color conversion element (4) includes: a phosphor layer (44) that includes at least one type of phosphor (441); a reflecting layer (43) stacked on the phosphor layer (44); a substrate (41) disposed in a position opposite to the reflecting layer (43); a joining portion (42) interposed between the reflecting layer (43) and the substrate (41) for joining the reflecting layer (43) and the substrate (41); and an absorbing portion (45) disposed above a principal surface (411) of the substrate (41) closer to the joining portion (42). The absorbing portion (45) is covered with the joining portion (42) and absorbs laser light having a wavelength that excites the phosphor (441).