Endoscope Light Source Device Using Glass Rod for Etendue Matching

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Solution Overview

Problem

Existing light source devices for endoscopes face inefficiencies in light transmission and illumination uniformity due to mismatched optical fiber diameters and etendue considerations, leading to light loss and uneven illumination.

Innovation Solution

A light source device for endoscopes incorporating multiple excitation laser light sources, optical fiber bundles, and a glass rod with optimized diameters and etendue management, ensuring efficient light guidance and uniform illumination through magnification optical systems and careful alignment of emission ends.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If optical fiber bundles with standard diameters are used to transmit light from laser sources, then the device structure is simplified, but light transmission efficiency decreases due to etendue mismatch

Engineering Contradiction:
Improvelight transmission efficiencyVSAvoidoptical system complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

A glass rod with optimized diameter serves as an intermediary optical element between the laser source and the optical fiber bundle. The glass rod acts as a magnification optical system that transforms the etendue of the laser light to match the acceptance etendue of the optical fiber bundle, thereby maximizing light transmission efficiency while maintaining a relatively simple device structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If multiple optical fiber bundles are used to carry different excitation lights, then multiple wavelengths can be transmitted, but illumination uniformity deteriorates due to diameter mismatches

Engineering Contradiction:
Improvemulti-wavelength transmission capabilityVSAvoidillumination uniformity
Core Design Contradiction:
Adaptability or versatilityVSIllumination intensity

Solution Approach 1:

Each optical fiber bundle is individually optimized with a specific diameter matched to the etendue of its corresponding excitation laser source. This local optimization ensures that each wavelength channel achieves maximum light transmission efficiency. The glass rod further refines the light distribution to ensure uniform illumination across all wavelengths at the distal end.

Inventive Principle:
Principle #3Local quality

3Volume of moving object

If optical fiber bundles are directly connected to the light source without etendue matching, then the device size is reduced, but light loss increases

Engineering Contradiction:
Improvedevice sizeVSAvoidlight loss
Core Design Contradiction:
Volume of moving objectVSLoss of energy

Solution Approach 1:

The glass rod is designed with specific diameter parameters that create a magnification optical system. By carefully selecting the glass rod diameter and length, the etendue of the laser light is transformed to match the optical fiber bundle acceptance. This parameter optimization enables efficient light coupling without significantly increasing the overall device volume, as the glass rod can be made compact while achieving the required optical transformation.

Inventive Principle:
Principle #35Parameter changes

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

Enhances light transmission efficiency and achieves uniform illumination by aligning optical fiber bundles with the glass rod, reducing light loss and maintaining a compact device size while ensuring high-quality imaging.

Implementation Method 1

a first condensing optical system that is formed of a plurality of optical systems condensing excitation light generated from the plurality of excitation laser light sources, a second condensing optical system that condenses the white light emitted from the illumination light source

Methodology Applied
Scientific EffectOptical condensing: Lens

Implementation Method 2

a plurality of first optical fiber bundles on which the excitation light condensed by the plurality of optical systems is incident, a second optical fiber bundle on which the light emitted from the illumination light source and condensed by the second condensing optical system is incident

Methodology Applied
Scientific EffectOptical fiber transmission: Optical Fibre

Implementation Method 3

a first glass rod of which a first end surface is connected to emission end surfaces of the first and second optical fiber bundles

Methodology Applied
Scientific EffectLight transmission through glass rod: Refraction

Data Source

PatentEP4529826A1Light source device for endoscope
Publication Date: 2025.04.02 OLYMPUS CORPORATION(JP)
  • EP4529826A1 patent drawingFigure 1
  • EP4529826A1 patent drawingFigure 2
  • EP4529826A1 patent drawingFigure 3A~4B

AI summary

A light source device for an endoscope includes a plurality of excitation laser light sources, a plurality of first condensing optical systems, a plurality of first optical fiber bundles on which the excitation light condensed by the plurality of first condensing optical systems is incident, an illumination light source that generates white light, a second condensing optical system that condenses the white light emitted from the illumination light source, a second optical fiber bundle, and a first glass rod of which a first end surface is connected to emission end surfaces of the first and second optical fiber bundles and first emission ends of the first optical fiber bundles and a second emission end of the second optical fiber bundle are bundled. A connecting portion of an illumination optical system of an endoscope is provided on a second end surface of the first glass rod opposite to the first end surface.