LED Light Emitting Device with Segmented Wavelength Conversion
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Solution Overview
Problem
Conventional LED retrofits for incandescent lamps often appear yellowish or orange when switched off due to fluorescent materials, which is aesthetically undesirable and makes them less similar to classical incandescent bulbs.
Innovation Solution
A light-emitting device comprising multiple LED chips arranged on an elongated carrier with translucent elements and wavelength conversion materials, where the LED chips are enclosed between the translucent elements, and wavelength conversion elements are strategically placed to convert blue light into yellow, orange, and red light, ensuring the device emits white light and appears white or grey when off, mimicking incandescent lamps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If fluorescent materials are used to produce white light from blue LED chips, then white light emission is achieved, but the device appears yellowish or orange when switched off
Solution Approach 1:
The patent divides the wavelength conversion function into multiple separate fluorescent materials (yellow, orange, red) instead of using a single fluorescent material. This segmentation allows each material to contribute to different portions of the visible spectrum, enabling the device to appear white or grey when off while still emitting white light when on.
Solution Approach 2:
The patent uses a composite structure combining multiple fluorescent materials (yellow, orange, red) with blue LED chips. This composite approach creates a multi-component system where the combination of different fluorescent materials produces the desired aesthetic appearance when off and proper white light emission when on.
2Shape
If LED chips are arranged on an elongated carrier, then the device mimics the shape of incandescent lamps, but the structure becomes more complex
Solution Approach 1:
The elongated carrier serves multiple functions: it provides the filament-like shape for aesthetic purposes, acts as a mounting structure for the LED chips, and functions as part of the electrical connection system. This multi-functionality reduces the need for separate structural components.
Solution Approach 2:
The patent merges the structural support function and the electrical connection function into a single integrated carrier structure. The carrier both holds the LED chips in place and provides electrical pathways, eliminating the need for separate structural and electrical components.
3Illumination intensity
If translucent elements are added to enclose LED chips, then light distribution is improved and glare reduced, but device complexity increases
Solution Approach 1:
The patent uses thin translucent elements (such as translucent encapsulants or films) to enclose the LED chips. These thin-film structures provide the necessary light diffusion and glare reduction while adding minimal structural complexity compared to rigid enclosures.
Solution Approach 2:
The translucent elements act as intermediary components between the LED chips and the surrounding environment. They mediate the light output by diffusing it uniformly in all directions while protecting the LED chips, thereby improving light distribution without requiring complex optical 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
The solution allows for a discreet appearance when off and efficient light emission in all directions, reducing glare and achieving uniform light distribution, making the LED device more aesthetically and functionally similar to incandescent lamps.
Implementation Method 1
a light-emitting device has a plurality of light-emitting diode chips
Implementation Method 2
wavelength conversion elements are strategically placed to convert blue light into yellow, orange, and red light
Data Source
AI summary
A light emitting device is disclosed. In an embodiment a light-emitting device includes a plurality of light-emitting diode chips arranged on a mounting surface of a carrier, a first translucent element and a second translucent element, wherein the first translucent element is arranged over the plurality of light-emitting diode chips as viewed from the mounting surface and the second translucent element is disposed on a side of the plurality of light-emitting diode chips opposite the first translucent element such that the light-emitting diode chips are arranged between the first and second translucent elements, wherein the first and second translucent elements are configured to emit light generated by the light-emitting diode chips during operation outwardly, and wherein the first and second translucent elements appear white or grey in daylight.