LED Filament Elevated Phosphor Layer Flame Appearance
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Solution Overview
Problem
Existing LED filament light emitting devices struggle to achieve a decorative, incandescent-like appearance while efficiently emitting light in multiple wavelength ranges, particularly in separating and displaying different colors simultaneously.
Innovation Solution
The LED filament incorporates an elongated carrier with a first translucent layer that is substantially free from luminescent material and a second translucent layer containing luminescent material. The second layer is positioned on the outer surface of the first layer, allowing LED light to escape from the sides of the first layer, creating a color gradient that depends on the choice of LEDs and luminescent materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a single layer comprising a mixture of broad-band green and red photoluminescence materials is applied onto a LED-filament with blue-LEDs, then the decorative effect is enhanced, but different colors cannot be separated and displayed at the same time
Solution Approach 1:
The patent divides the luminescence function into separate layers: a first translucent layer that is substantially free from luminescent material allowing LED light to escape from sides, and a second translucent layer comprising luminescent material for color conversion. This segmentation enables different colors to be displayed simultaneously by controlling different LED groups, resolving the contradiction between manufacturing simplicity and color versatility.
Solution Approach 2:
The patent introduces a vertical dimension with multiple stacked translucent layers, where the first layer allows side emission of LED light and the second layer provides luminescent conversion. This multi-layer structure enables independent control of different color emissions from different layers, achieving color separation and simultaneous display while maintaining ease of manufacture.
2Adaptability or versatility
If the second elongated translucent layer is arranged on the outer surface of the first elongated translucent layer, then LED light can escape from the sides creating a color gradient, but the structure becomes more complex
Solution Approach 1:
The patent segments the luminescence function into two distinct layers: the first translucent layer handles light transmission and side emission, while the second translucent layer handles color conversion. This functional segmentation achieves color gradient capability through vertical stacking, where the simplicity of each individual layer compensates for the increased structural complexity.
Solution Approach 2:
The first translucent layer serves multiple functions: it protects the LEDs, allows light transmission, and enables side emission for color gradient effects. The second layer provides luminescent conversion. This multi-functionality approach justifies the multi-layer structure by consolidating multiple functions into each layer, reducing overall system complexity.
3Illumination intensity
If a first elongated translucent layer substantially free from luminescent material is used to allow LED light to escape from sides, then the luminescence is enhanced, but the quantity of light available for color conversion in the second layer is reduced
Solution Approach 1:
The patent segments the light emission paths: one path allows LED light to escape directly from the sides of the first translucent layer for high luminescence intensity, while another path directs light to the second translucent layer for color conversion. This segmentation resolves the contradiction by providing separate channels for direct emission and color-converted emission, both operating simultaneously with adequate light intensity.
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 enhances the luminescence and decorative effect of the LED filament, allowing for a color gradient that can be dynamically adjusted by controlling the LEDs, while achieving a flamelike appearance with warm white light.
Implementation Method 1
a second elongated translucent layer comprising a luminescent material configured to partly convert said LED light into converted light
Data Source
AI summary
A LED filament (2,20) configured to provide LED filament light. The LED filament comprising an elongated carrier (7) extending in a lengthwise direction, said elongated carrier comprising a first major surface (7a). The LED filament further comprises a plurality of LEDs (8) arranged on said first major surface and configured to emit LED light, a first layer (9) free from a luminescent material encapsulating or covering said plurality of LEDs and at least partly encapsulating or covering said first major surface, said first elongated translucent layer having a width, W1, transverse to said lengthwise direction, and a second layer (10) comprising a luminescent material configured to partly convert said LED light, the second layer is arranged on an outer surface (9a) of said first layer, such that the second layer is contained within the width, W1, of the first layer.