LED Light Guide Collimating Element Reflective Recapture
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Solution Overview
Problem
Existing LED spot devices are bulky due to the need for individual collimators, which leads to reduced area-averaged luminance and high production costs, and current solutions like optical manifolds result in significant light loss when combining light from multiple LEDs.
Innovation Solution
A light emitting device with a collimating element made of transparent material and a reflective element that encloses the light guiding element, allowing reflected light to be injected back into the collimating element, reducing the need for multiple collimators and minimizing light loss, resulting in a more compact and cost-effective design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If individual collimators are used for each LED source, then collimation quality is improved, but device bulkiness increases and production costs rise
Solution Approach 1:
The patent merges multiple LED sources and their individual collimation functions into a single integrated light guide structure. Instead of separate collimators for each LED, the invention uses one light guide with multiple input surfaces that combines light from multiple LEDs and provides collimation through a single output surface, thereby reducing device bulkiness while maintaining collimation quality.
Solution Approach 2:
The light guide structure performs multiple functions simultaneously: it acts as both the combining element for multiple LED inputs and the collimation element for the unified output. This multi-functional design eliminates the need for separate collimators for each LED, reducing overall device volume and production complexity.
2Volume of moving object
If LED sources are placed very close together to reduce bulkiness, then device size is reduced, but thermal management becomes problematic
Solution Approach 1:
The patent arranges multiple LED sources and light guide input surfaces in a planar configuration rather than stacking them vertically. This lateral arrangement allows sufficient thermal spacing between LED sources while maintaining a compact overall device footprint, effectively managing heat generation without increasing bulkiness.
3Temperature
If gaps are introduced between LEDs for heat spreading, then thermal management is improved, but area-averaged luminance is reduced
Solution Approach 1:
The light guide structure merges light from multiple LED sources into a single unified output beam. The gaps between LEDs for thermal management do not affect the optical combining function, as the light guide collects and redirects light from all LED input surfaces into one collimated output, maintaining high area-averaged luminance despite physical spacing between sources.
4Adaptability or versatility
If optical manifolds are used to combine light from multiple LEDs, then light combination is achieved, but light loss increases significantly
Solution Approach 1:
The patent replaces the traditional optical manifold structure with a light guide based system that uses total internal reflection and refractive index differences to guide and combine light. This substitution eliminates the high light losses associated with optical manifold interfaces and geometries, achieving efficient light combination with minimal energy loss.
Solution Approach 2:
The invention optimizes the refractive index parameters of the light guide material and the geometric parameters of the light guide structure (input surface areas, output surface geometry, internal pathways) to maximize light transmission efficiency. By carefully controlling these parameters, the system achieves high light combination efficiency with minimal loss.
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 achieves a high-quality, high-intensity light output with increased flux per area, reducing the bulkiness and production costs of LED devices while minimizing light loss during combination, and allows for a more compact structure.
Implementation Method 1
a light guiding element comprising a light guide input surface being arranged adjacent the LED output surface of each LED of the plurality of LEDs such that the light emitted by the plurality of LEDs is injected into the light guiding element at the light guide input surface, the light being injected into the light guiding element at the light guide input surface further being guided to and emitted from the light guide output surface
Implementation Method 2
a collimating element made of a transparent material and comprising a first surface section arranged adjacent the light guide output surface, the collimating element being adapted to collimate light emitted from the light guide output surface and injected into the collimating element at the first surface section
Implementation Method 3
a first reflective element arranged such as to enclose at least the light guiding element at least partially and wherein the collimating element comprises a second surface section, wherein the first reflective element is adapted to inject at least a part of light reflected back by the first reflective element into the collimating element at said second surface section
Data Source
AI summary
A light emitting device (1, 101) comprising a plurality of LEDs (2), each LED (21, 22, 23) of said plurality of LEDs comprising a LED output surface (24, 25, 26) and being arranged to, in operation, emit light from said LED output surface, a light guiding element (3) comprising a light guide input surface (31) being arranged adjacent said LED output surface of each LED of said plurality of LEDs such that said light emitted by said plurality of LEDs is injected into the light guiding element at said light guide input surface, said light guiding element further comprising a light guide output surface (34), said light being injected into the light guiding element at said light guide input surface further being guided to and emitted from said light guide output surface, and a collimating element (4) made of a transparent material and comprising a first surface section (41) arranged adjacent said light guide output surface and said collimating element being adapted to collimate light emitted from said light guide output surface and injected into said collimating element at said first surface section, the light emitting device further comprising a first reflective element (5) arranged such as to enclose at least said light guiding element at least partially and wherein said collimating element comprises a second surface section (42), wherein the first reflective element is adapted to inject at least a part of light reflected back by the first reflective element into said collimating element at said second surface section.