Solid State Lamp Thermal Spreading and Light Directing Optics
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Solution Overview
Problem
Conventional LED lamps face inefficiencies due to heat retention issues and undesirable aesthetic characteristics, particularly with remote phosphor arrangements, which can lead to elevated operating temperatures and reduced conversion efficiency, and they often produce directional light patterns rather than omnidirectional ones, making them less suitable for replacing traditional incandescent bulbs.
Innovation Solution
The development of LED lamps with remote wavelength conversion materials and a separate diffusing layer, combined with thermal management features like heat-spreading substrates and dielectric layers, allows for efficient heat dissipation and transformation of directional light into an omnidirectional emission pattern, mimicking the light distribution of incandescent bulbs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If remote phosphor arrangement is used, then conversion efficiency is improved, but operating temperature increases
Solution Approach 1:
The patent divides the lamp structure into distinct functional zones: a remote phosphor layer spaced from the LED array, a separate diffusing layer, and a light mixing chamber. This segmentation allows the phosphor to be positioned where it can efficiently convert LED light while being thermally managed separately, reducing operating temperature at the phosphor conversion site.
Solution Approach 2:
The patent introduces a light mixing chamber as an intermediary space between the remote phosphor and the diffusing layer. This chamber allows light from both the LED array and the phosphor to mix and redistribute before reaching the diffuser, improving overall conversion efficiency while managing thermal distribution across the system.
2Illumination intensity
If directional light pattern is produced, then light intensity is improved, but aesthetic appeal deteriorates
Solution Approach 1:
The patent transitions from the typical planar LED mounting to a three-dimensional configuration with the LED array positioned at the bottom, remote phosphor layer above it, and a diffusing layer at the top. This vertical stacking creates omnidirectional light distribution that mimics traditional incandescent bulb aesthetics while maintaining LED efficiency.
Solution Approach 2:
The patent uses a diffusing layer that scatters and redistributes light uniformly in all directions, transforming the directional high-intensity LED output into a soft, omnidirectional glow that resembles traditional incandescent lighting. This maintains aesthetic appeal while preserving the energy efficiency of LED technology.
3Reliability
If heat dissipation is improved, then reliability is improved, but device complexity increases
Solution Approach 1:
The patent designs the lamp housing to serve multiple functions: it provides structural support, acts as the light mixing chamber, facilitates heat dissipation through its geometry, and supports the diffusing layer. This multi-functionality improves reliability through better thermal management without significantly increasing device complexity.
Solution Approach 2:
The patent combines the light mixing chamber and heat dissipation structure into a single integrated housing design. The housing simultaneously manages both optical and thermal functions, improving reliability by efficiently dissipating heat from the LED array and remote phosphor while maintaining the omnidirectional light distribution pattern.
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 solution enables LED lamps to operate at lower temperatures, maintain high conversion efficiency, and produce a uniform, omnidirectional light pattern, enhancing both performance and aesthetic appeal, making them suitable replacements for traditional lighting solutions.
Implementation Method 1
a heat spreading substrate included on the dielectric layer... The heat spreading substrate is arranged to spread heat from the LED
Implementation Method 2
An optical element over the LED changes the emission pattern of the LED to a broader emission pattern
Implementation Method 3
a phosphor carrier over the optical element, the phosphor carrier converting at least some of the LED light to a different wavelength
Data Source
AI summary
Lamps and bulbs are disclosed generally comprising different combinations and arrangements of a light source, one or more wavelength conversion materials, regions or layers which are positioned separately or remotely with respect to the light source, and a separate diffusing layer. This arrangement allows for the fabrication of lamps and bulbs that are efficient, reliable and cost effective and can provide an essentially omni-directional emission pattern, even with a light source comprised of a co-planar arrangement of LEDs. The lamps according to the present invention can also comprise thermal management features that provide for efficient dissipation of heat from the LEDs, which in turn allows the LEDs to operate at lower temperatures. The lamps can also comprise optical elements to help change the emission pattern from the generally directional (e.g. Lambertian) pattern of the LEDs to a more omni-directional pattern.