Light Guide Groove Structuring for Homogeneous LED Mixing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional lighting arrangements with light guide elements struggle to effectively couple and mix light from multiple LEDs with different spectral emissions, leading to inhomogeneous light emission and color fringes.
Innovation Solution
A lighting arrangement featuring a flat or rod-shaped light guide element with a coupling-in surface structured for optimal light coupling and a second structuring on the main surface in the form of a groove, which acts as a reflection surface to enhance light homogenization, allowing for the mixing of white light LEDs with varying color temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If light is coupled into the light guide element from multiple LEDs with different spectral emissions, then the light emission area is provided, but inhomogeneous light emission and color fringes occur due to insufficient light mixing
Solution Approach 1:
The light guide element is divided into multiple coupling regions, each assigned to a specific LED element. Each coupling region has its own structuring section with groove patterns that independently process light from corresponding LEDs, enabling localized light mixing before overall homogenization across the light guide element.
Solution Approach 2:
Different groove patterns are applied in different regions of the light guide element based on local requirements. The groove depth, spacing, and orientation are locally optimized to match the spectral characteristics and emission patterns of individual LEDs, improving light mixing efficiency at each location while maintaining overall homogeneity.
2Device complexity
If a flat coupling surface is used for light coupling, then the structure is simple, but light mixing is insufficient leading to color fringes
Solution Approach 1:
Groove patterns with curved profiles are introduced into the coupling surface and main surfaces of the light guide element. These curved groove structures create multiple internal reflections and refraction paths for the coupled light, significantly enhancing light mixing while maintaining a relatively simple overall geometry that can be manufactured using standard molding techniques.
3Stability of the object's composition
If multiple structuring sections are added to improve light mixing, then light homogenization improves, but the manufacturing complexity increases
Solution Approach 1:
The groove patterns serve multiple functions simultaneously: they act as coupling surfaces for light entry, create internal reflection paths for light mixing, and define optical waveguides for light propagation. This multi-functionality reduces the need for separate structural elements, simplifying the manufacturing process while achieving effective light homogenization.
Solution Approach 2:
The groove patterns are designed with specific parameter ranges (depth, width, spacing, orientation) that can be adjusted based on the LED characteristics and desired light distribution. By optimizing these parameters within feasible manufacturing tolerances, effective light mixing is achieved without requiring excessively complex or precise manufacturing processes.
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 improves light mixing and homogenization within the light guide element, ensuring uniform light emission and reducing color fringes by utilizing a groove structuring on the main surface to direct and reflect light effectively, even when using LEDs with different color temperatures.
Implementation Method 1
the boundary surface of which is designed as a reflection surface
Data Source
Figure 1a~1b
Figure 2a
Figure 2b
AI summary
The invention relates to a planar or rod-shaped light guide element with opposing main sides and connecting narrow sides, wherein at least one of the narrow sides is designed for coupling light from a light source comprising at least one LED element, and wherein the at least one coupling narrow side has a structuring section associated with the LED element for forming a coupling surface. The light guide element according to the invention is characterized in that the light guide element, following the at least one structuring section (S) associated with a coupling surface, extends in the direction of light guidance (F).Perpendicular to the coupling plane, at least one of the main surfaces (2, 3) has a second structure for homogenizing the coupled light in the form of a groove structure extending from the coupling surfaces (6, 6', 8-10), wherein the respective main surface (2, 3) has at least one groove-shaped recess (90) whose boundary surface is designed as a reflective surface. The invention further relates to a lighting arrangement with a light source and such a planar or rod-shaped light guide element (Fig. 7).