LED Illumination Device with Wavelength Converting Plate
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Solution Overview
Problem
Current LED-based illumination devices face limitations in light output level, color quality due to color point instability, poor color rendering, and spatial/angular variations, and are expensive due to the need for color control electronics and sensors.
Innovation Solution
The design incorporates a plurality of LEDs mounted on a board with a transmissive plate coated with wavelength converting material, a base reflector structure for heat dissipation, and a dam of reflective and thermally conductive materials to enhance light extraction efficiency and heat management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If LEDs are used as light source, then energy efficiency is improved, but light output level and color quality deteriorate
Solution Approach 1:
The patent combines multiple LEDs into a single integrated illumination device with a common heat dissipation structure and optical system, merging their light output to achieve high illumination levels while maintaining LED energy efficiency. The multiple LEDs work together as a unified light source rather than separate devices.
Solution Approach 2:
The illumination device integrates multiple functions into a single structure: heat dissipation, color mixing, light extraction, and optical direction. The transmissive plate serves both as a color mixing medium and as part of the light extraction optics, while the heat dissipation structure also provides mechanical support.
2Use of energy by moving object
If LEDs are used as light source, then energy efficiency is improved, but color quality deteriorates due to color point instability
Solution Approach 1:
The patent applies different wavelength converting materials at different locations on the transmissive plate to compensate for spatial variations in LED color output. Each region of the transmissive plate has tailored phosphor composition to correct the specific color characteristics of underlying LEDs, achieving uniform overall color output.
Solution Approach 2:
The illumination device exploits temporal changes in LED characteristics by designing the transmissive plate with wavelength converting materials that compensate for color drift over time and temperature. The phosphor formulation is specifically chosen to maintain stable color point as LEDs age and thermal conditions vary.
3Use of energy by moving object
If LEDs are used as light source, then energy efficiency is improved, but color rendering deteriorates
Solution Approach 1:
The patent uses different wavelength converting materials at different locations on the transmissive plate to create a spectrally enriched light output. Specific phosphors are placed in regions where their emission spectra will fill gaps in the overall spectrum, improving color rendering while maintaining LED energy efficiency.
4Stability of the object's composition
If color control electronics and sensors are added, then color quality is improved, but device complexity and cost increase
Solution Approach 1:
The illumination device achieves color control without external electronics by using the transmissive plate with wavelength converting materials that passively compensate for LED color variations. The optical structure itself performs the color correction function that would otherwise require active sensing and control systems.
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 improves light extraction efficiency, stabilizes color quality, and reduces costs by integrating heat dissipation and color control in a single structure, addressing the limitations of existing LED-based illumination devices.
Implementation Method 1
The transmissive plate includes an amount of wavelength converting material configured to change a wavelength of an amount of light emitted by the plurality of LEDs
Implementation Method 2
a dam of reflective material surrounds the LEDs and is coupled to the LED mounting board and the transmissive plate
Implementation Method 3
a dam of thermally conductive material surrounds the dam of reflective material
Data Source
AI summary
A light emitting diode (LED) based illumination device include a plurality of LEDS mounted to mounting board and includes a transmissive plate disposed above the LEDs. The transmissive plate includes an amount of wavelength converting material configured to change a wavelength of an amount of light emitted by the plurality of LEDs. A base reflector structure is coupled to the LED mounting board and the transmissive plate between at least two of the LEDs. In another configuration, a dam of reflective material surrounds the LEDs and is coupled to the LED mounting board and the transmissive plate, while a dam of thermally conductive material surrounds the dam of reflective material. In another configuration, the LED mounting board has a protrusion of thermally conductive material that surrounds the LEDs and is coupled to the transmissive plate, and has a void on the side opposite the protrusion.