Freeform Optics for Homogeneous LED Beam Mapping

Solution Overview

Problem

Existing optical wireless communication systems face challenges in achieving efficient and cost-effective radiation distribution within a well-defined spot using LEDs, due to their wide radiation profile and high manufacturing costs when combined with lenses and mirrors, especially in non-rotationally symmetrical channels.

Innovation Solution

The use of an optics concept that combines refraction and total internal reflection regions within a single optical body, allowing for efficient beam mapping and power distribution, reducing system complexity and manufacturing costs by eliminating the need for separate lenses and mirrors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If LEDs are used as emitters due to their low cost and high output power, then manufacturing cost is reduced, but the radiation profile becomes very wide making it difficult to transfer radiation to a well-defined spot with homogenous power distribution

Engineering Contradiction:

Improvemanufacturing costVSAvoidpower distribution homogeneity

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent merges the functions of multiple optical components (lenses and mirrors) into a single integrated optical element. This element combines refractive regions and reflective regions within one component, eliminating the need for separate lenses and mirrors while achieving the desired beam shaping and power distribution homogeneity.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The single optical element performs multiple functions simultaneously: it focuses light, shapes the beam, distributes power homogeneously, and defines the spot boundaries. This multi-functional design replaces what previously required multiple specialized components, reducing both complexity and manufacturing cost.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Manufacturing precision

If a combination of lenses and mirrors is used to achieve well-defined spot with homogenous power distribution, then power distribution homogeneity is improved, but the overall system becomes comparatively large and manufacturing costs increase

Engineering Contradiction:

Improvepower distribution homogeneityVSAvoidsystem size

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent merges the functions of multiple optical components (lenses and mirrors) into a single integrated optical element. This element combines refractive regions and reflective regions within one component, eliminating the need for separate lenses and mirrors while achieving the desired beam shaping and power distribution homogeneity.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The optical element utilizes three-dimensional freeform surfaces with varying curvatures to achieve complex optical functions in a compact form factor. By employing non-rotationally symmetrical freeform optics, the design achieves sophisticated beam control without requiring multiple sequential components.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Adaptability or versatility

If non-rotationally symmetrical freeform optics are used for non-rotationally symmetrical channels, then adaptability to channel geometry is improved, but manufacturing costs become particularly critical

Engineering Contradiction:

Improvechannel geometry adaptabilityVSAvoidmanufacturing cost

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The single optical element performs multiple functions simultaneously: it focuses light, shapes the beam, distributes power homogeneously, and defines the spot boundaries. This multi-functional design replaces what previously required multiple specialized components, reducing both complexity and manufacturing cost.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent employs freeform surfaces with continuously varying curvatures and asymmetrical geometries to match non-rotationally symmetrical communication channels. By optimizing the surface parameters of the single optical element, the design achieves high adaptability to channel geometry while maintaining manufacturability through monolithic fabrication.

Inventive Principle:

Principle #35Parameter changes

4Speed

If mirrors are used in the optical system to achieve beam shaping, then beam direction control is improved, but absorption losses occur at the mirror

Engineering Contradiction:

Improvebeam direction controlVSAvoidabsorption loss

Core Design Contradiction:

SpeedVSLoss of energy

Solution Approach 1:

The patent merges the functions of multiple optical components (lenses and mirrors) into a single integrated optical element. This element combines refractive regions and reflective regions within one component, eliminating the need for separate lenses and mirrors while achieving the desired beam shaping and power distribution homogeneity.

Inventive Principle:

Principle #5Merging (Combining)

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 approach enables high-efficiency radiation distribution with homogenous power within the spot, reducing manufacturing costs and increasing data rate through multiple input-multiple output (MIMO) systems, while minimizing reflection losses and allowing for compact, efficient communication channels.

Implementation Method 1

the first interface forms a first central lens region and a first refraction region surrounding the first central lens region, and wherein the second interface forms a second central lens region and a second refraction region surrounding the second central lens region; wherein the first and second lens regions are configured to map a first beam group in the direction of the main radiation direction

Methodology Applied

Scientific EffectRefraction: Refraction

Implementation Method 2

a lateral interface of any shape having a total internal reflection region; wherein the second refraction region of the second interface is configured to map a second beam group along a second radiation direction which is angled to the main radiation direction

Methodology Applied

Scientific EffectTotal internal reflection: Total Internal Reflection

Data Source

PatentUS12092806B2Optics for transmission and/or reception element

Publication Date: 2024.09.17 FRAUNHOFER GESELLSCHAFT ZUR FORDERUNG DER ANGEWANDTEN FORSCHUNG EV

AI summary

Optics for a transmission and/or reception element configured to emit and/or receive a signal in a main radiation direction has an optical body formed of a material optically transparent for the communication wavelength. It has a cavity within which the transmission/reception element is arranged, wherein a first interface is formed between the cavity and the optical body. Furthermore, the optical body has a second interface formed opposite the cavity and a lateral interface having a total internal reflection region. The first interface forms a first central lens region and a first refraction region surrounding the first central lens region. The second interface forms a second central lens region and a second refraction region surrounding the second central lens region. All the surfaces or areas described are defined to be freeform areas so that they can exhibit any shape. In addition, it is conceivable to introduce Fresnel patterns in the surfaces.