Rotating Microlens Illumination for Homogeneous Laser Light

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Solution Overview

Problem

Existing optical illumination devices for laser equipment are large and costly due to the need for multiple components to disrupt laser light coherence and achieve homogeneous illumination, which complicates the optical path and increases size and expense.

Innovation Solution

An optical illumination device featuring a laser light source, rotating microlens arrays arranged in a spiral configuration, and a Fourier lens, which homogenizes and disrupts laser light coherence without a diffuser, simplifying the configuration and reducing size and cost.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If a diffuser and relay lens are added to disrupt laser light coherence, then homogeneity of illumination is improved, but device size and complexity increase

Engineering Contradiction:
Improvehomogeneity of illuminationVSAvoiddevice complexity
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the diffuser component from the optical path while maintaining coherence disruption functionality through the rotating microlens array alone, thereby simplifying the device structure without compromising illumination homogeneity

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces dynamic rotation of the microlens array to achieve coherence disruption and homogeneity improvement, replacing the need for additional static optical components like diffusers and relay lenses

Inventive Principle:
Principle #15Dynamics

2Illumination intensity

If multiple optical components are used to achieve homogeneous illumination, then illumination quality is improved, but the optical path length and device size increase

Engineering Contradiction:
Improvehomogeneity of illuminationVSAvoidoptical path length
Core Design Contradiction:
Illumination intensityVSLength of stationary object

Solution Approach 1:

The patent merges the functions of coherence disruption and illumination homogenization into a single rotating microlens array component, eliminating the need for separate diffuser and relay lens elements, thereby shortening the optical path length

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The rotating microlens array dynamically performs multiple optical functions that would traditionally require multiple static components, reducing the overall optical path length and device size

Inventive Principle:
Principle #15Dynamics

3Stability of the object's composition

If a diffuser is inserted in the optical path to decrease interference influence, then homogeneity is improved, but device cost and complexity increase

Engineering Contradiction:
Improvehomogeneity of illuminationVSAvoiddevice complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent removes the diffuser component from the optical path while achieving the same homogeneity improvement effect through the rotating microlens array, thereby reducing device complexity and cost

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the static diffuser material-based coherence disruption mechanism with a dynamic mechanical rotation of microlens arrays, achieving similar homogeneity results with simpler and less expensive components

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 device achieves homogeneous illumination with reduced interference and diffraction, enabling smaller, more cost-effective designs while maintaining stable optical characteristics for improved analysis accuracy in applications like laser microscopes.

Implementation Method 1

A microlens array is configured to rotate around an axis which is perpendicular to the microlens array. The moving mechanism causes the microlens array to rotate around the axis.

Methodology Applied
Scientific EffectRotation:

Implementation Method 2

one or more microlens arrays through which light emitted from the laser light source passes; a Fourier lens through which light passing through the microlens array passes

Methodology Applied
Scientific EffectLens focusing: Lens

Implementation Method 3

a Fourier lens through which light passing through the microlens array passes. The plurality of microlens arrays and the Fourier lens constitute a Koehler illumination system.

Methodology Applied
Scientific EffectFourier transformation:

Data Source

PatentEP3779556B1Optical illumination device
Publication Date: 2024.06.26 YOKOGAWA ELECTRIC CORP
  • EP3779556B1 patent drawingFigure 1
  • EP3779556B1 patent drawingFigure 2~4
  • EP3779556B1 patent drawingFigure 5

AI summary

An optical illumination device (10) includes: a laser light source (1); microlens arrays (2, 3) through which light emitted from the laser light source (1) passes; a moving mechanism (5) that moves the microlens arrays (2, 3) without changing an optical length from the laser light source (1); and a Fourier lens (4) through which light passing through the microlens arrays (2, 3) passes.