Optical Beam Former with Misaligned Microlens Arrays

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Solution Overview

Problem

Existing beam shaping technologies for far-field distributions face challenges in generating sharp edges and maintaining high system efficiency, with diffusers limiting intensity profile shaping and arrayed projectors suffering from significant transmission loss and stray light issues.

Innovation Solution

A double-sided microlens array with a shared exit microlens and a larger number of condenser lenses compared to projection lenses, allowing for easy manufacturing and high-quality far-field distributions with reduced stray light and artifacts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a diffuser is used for far-field beam shaping, then arbitrary intensity profiles can be achieved, but sharp edges of the beam cannot be generated and the centroid cannot be controlled independently

Engineering Contradiction:
Improvearbitrary intensity profile shapingVSAvoidsharp edge generation
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The optical system is segmented into multiple discrete channels, each with its own microlens and absorbing mask. This segmentation allows independent control of each beam channel, enabling sharp edges through precise mask positioning while maintaining arbitrary intensity profiling through channel-wise absorption control.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Absorbing masks are introduced as intermediary elements between the microlenses and the far-field region. These masks serve as mediators that selectively block light in specific channels, enabling precise intensity control and sharp edge formation without requiring complex diffuser surface geometries.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If absorbing masks are used in each channel of a double-sided microlens array, then arbitrary continuous beam shaping is achieved, but significant transmission loss and reduced optical efficiency occur

Engineering Contradiction:
Improvearbitrary continuous beam shapingVSAvoidsystem transmission
Core Design Contradiction:
Adaptability or versatilityVSLoss of energy

Solution Approach 1:

Absorption is applied locally only where needed in specific channels rather than throughout the entire optical path. The absorbing masks are positioned and sized to provide precise local intensity control, minimizing unnecessary absorption and maintaining high transmission in channels where full intensity is required.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

Absorption is applied partially only in the extent necessary to achieve the desired intensity profile. The absorbing masks are designed with optimal size and positioning to provide just enough absorption for the required beam shaping, avoiding excessive absorption that would reduce overall system transmission.

Inventive Principle:
Principle #16Partial or excessive action

3Adaptability or versatility

If an irregular Fly's Eye Condenser with maskless double-sided microlens array is used, then arbitrary continuous intensity profiles are achievable, but stray light is caused by profile height jumps between neighboring microlenses

Engineering Contradiction:
Improvearbitrary continuous intensity profilesVSAvoidstray light
Core Design Contradiction:
Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

Instead of creating physical irregularities in the microlens array, the invention uses absorbing masks to copy the desired intensity profile through selective channel blocking. This virtual copying approach achieves arbitrary intensity distributions without the physical height jumps that cause stray light in irregular microlens arrays.

Inventive Principle:
Principle #26Copying

4Ease of manufacture

If a regular Fly's Eye Condenser with equal number of condenser and projection lenses is used, then manufacturing is simplified, but design freedom is limited

Engineering Contradiction:
Improvelens array manufacturingVSAvoiddesign freedom
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The lens array is segmented into channels with different numbers of condenser and projection lenses. This segmentation allows independent optimization of each channel's optical path, providing design freedom for complex beam shaping while maintaining regular, manufacturable lens structures within each segment.

Inventive Principle:
Principle #1Segmentation

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 the projection of sharp edges in the far field while maintaining high system efficiency, achieving complex arbitrary intensity profiles without absorbing elements or irregular structures.

Implementation Method 1

a condenser lens array (C) comprising a first plurality of condenser lenses (C0-C6), the first plurality of condenser lenses configured for receiving the incident light beam (12)

Methodology Applied
Scientific EffectLight focusing: Lens

Implementation Method 2

a projection lens array (P) comprising a second plurality of projection lenses (P0-P7) configured for receiving light from the condenser lens array (C) and for radiating the emerging light beam (14)

Methodology Applied
Scientific EffectLight projection: Lens

Data Source

PatentEP4343389A1Optical beam former, high beam headlight and method for projecting incident light
Publication Date: 2024.03.27 FRAUNHOFER GESELLSCHAFT ZUR FORDERUNG DER ANGEWANDTEN FORSCHUNG EV
  • EP4343389A1 patent drawingFigure 1
  • EP4343389A1 patent drawingFigure 2
  • EP4343389A1 patent drawingFigure 3

AI summary

An optical beam former for generating an emerging light beam from an incident light beam comprises a condenser lens array comprising a first plurality of condenser lenses, the first plurality of condenser lenses configured for receiving the incident light beam. The optical beam former comprises a projection lens array comprising a second plurality of projection lenses configured for receiving light from the condenser lens array and for radiating the emerging light beam. A number of the first plurality of condenser lenses is larger than a number of the second plurality of projection lenses and an edge of a projection lens is misaligned with regard to an opposing condenser lens.