LED Light Source With Optical Coupler for High Luminance
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Solution Overview
Problem
Semiconductor light sources, such as LEDs, face challenges in achieving high luminance while maintaining a small footprint, as reducing their size decreases light flux, and closely packing them leads to thermal management and addressability issues.
Innovation Solution
A light source comprising a plurality of LEDs arranged in a 2-dimensional array with a small light output section and an optically transmissive structure that collects and confines light, re-emitting it through a secondary surface of smaller area, allowing for spaced LED placement and increased luminance without the need for close packing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the size of semiconductor light sources is reduced to achieve miniaturization, then the footprint area is reduced, but the generated light flux decreases
Solution Approach 1:
Multiple semiconductor light sources are combined into a single light source assembly, where their light output sections are optically coupled to a common light output. This merging allows the individual light sources to be spaced apart (maintaining larger footprint for thermal management) while presenting a smaller effective light output area, thus resolving the contradiction between footprint area and light flux.
Solution Approach 2:
An optical coupling structure (comprising the light output section and light output interface) acts as an intermediary between the spaced-apart semiconductor light sources and the external environment. This intermediary collects light from multiple sources and presents it through a smaller effective area, enabling miniaturization of the light output while maintaining high light flux from distributed sources.
2Area of stationary object
If semiconductor light sources are closely packed to reduce footprint area, then the area is reduced, but thermal management becomes difficult
Solution Approach 1:
The light source assembly is segmented into multiple independent semiconductor light sources that are spaced apart rather than closely packed. Each light source maintains its own thermal zone, allowing for effective heat dissipation while the optical coupling structure integrates their light output. This segmentation resolves the thermal management issue while achieving miniaturization through optical integration.
3Area of stationary object
If semiconductor light sources are closely packed to reduce footprint area, then the area is reduced, but addressability limitations occur due to current density in conductive tracks
Solution Approach 1:
The light source assembly is segmented into multiple independently addressable semiconductor light sources spaced apart from each other. This spatial separation allows individual addressing of each light source through conductive tracks without excessive current density, while the optical coupling structure integrates their output. This segmentation resolves the addressability limitation while achieving compact footprint.
4Illumination intensity
If the light output section area is reduced to increase luminance, then luminance is improved, but the light generating area is reduced
Solution Approach 1:
Multiple light generating areas (semiconductor light sources) are merged optically into a single light output section. The light output section area is smaller than the combined area of all light generating regions, achieving increased luminance through the concentration of light from multiple sources while maintaining adequate light generating area through spatial distribution.
Solution Approach 2:
The optical coupling structure serves as an intermediary that collects light from distributed light generating areas and presents it through a smaller light output section. This intermediary enables the decoupling of light generation area from light output area, achieving high luminance through efficient light collection and concentration rather than simply reducing the generating area.
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 enables a high-luminance, pixelated light source with reduced thermal management issues and increased spacing between LEDs, allowing for more powerful LEDs and flexible light distribution, while maintaining a compact emitting surface.
Implementation Method 1
The optically transmissive structure may be adapted to confine received light by total internal reflection and thus reflect received light towards the light exit section
Implementation Method 2
a plurality of LED light sources arranged in a 2-dimensional array, each of the plurality of LED light sources having: a semiconductor diode structure adapted to generate light
Data Source
Figure 1A~1B
Figure 2A~2C
Figure 3A~3C
AI summary
Proposed is a light source comprising: a plurality of LED light sources, each of the plurality of LED light sources having: a semiconductor diode structure adapted to generate light; and a light output section above the semiconductor diode structure adapted to output light from the semiconductor diode structure, the area of the light output section being less than the area of the semiconductor diode structure; and an optically transmissive structure overlapping the light output sections of the plurality of LED light sources so as to receive light from the light output sections of the plurality of LED light sources and having a light exit section adapted to output the received light. The area of the light exit section of the optically transmissive structure is less than the footprint area of the plurality of LED light sources.