Endoscope Illumination Optics With Stepped Reflective-Absorbing Structure

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Solution Overview

Problem

Existing illumination optical systems for endoscopes are large, exhibit light distribution unevenness, and have poor transmission efficiency.

Innovation Solution

An illumination optical system with a stepped structure and concave surface portions on the light guide side, featuring a light reflecting surface on one side and a light absorbing surface on the other, along with specific curvature and dimensional constraints, to achieve size reduction, wide light distribution, and improved transmission efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the illumination optical system uses a conventional structure, then it can transmit light, but the system becomes large and heavy

Engineering Contradiction:

Improvesize of illumination optical systemVSAvoidlight transmission efficiency

Core Design Contradiction:

Volume of moving objectVSReliability

Solution Approach 1:

The illumination optical system is divided into multiple functional sections: a light incident side convex lens for light collection, a light reflecting surface for direction control, and a light emitting side concave lens for light distribution. This segmentation allows each component to be optimized for its specific function while maintaining overall compactness.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system transitions from a simple linear light path to a multi-dimensional optical path by introducing the convex lens (light incident side), the light reflecting surface, and the concave lens (light emitting side). This dimensional arrangement enables compact packaging while maintaining effective light transmission.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Illumination intensity

If the illumination optical system uses a conventional structure, then it can illuminate the target, but light distribution becomes uneven

Engineering Contradiction:

Improvelight distribution uniformityVSAvoidoptical system structure

Core Design Contradiction:

Illumination intensityVSDevice complexity

Solution Approach 1:

The light reflecting surface is designed with specific local properties: it reflects light from the convex lens to the concave lens, and its surface shape and position are precisely controlled to ensure uniform light distribution. This localized optimization of the reflecting surface achieves uniform illumination without requiring complex overall system redesign.

Inventive Principle:

Principle #3Local quality

3Loss of energy

If the illumination optical system uses a conventional structure, then it can transmit light, but transmission efficiency is poor due to light absorption

Engineering Contradiction:

Improvelight absorption lossVSAvoidoptical system structure

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

The light reflecting surface is designed to reflect light that would otherwise be absorbed or lost. By strategically positioning the reflecting surface between the convex lens and concave lens, light paths that would normally result in energy loss are converted into useful illumination paths, significantly reducing light absorption loss.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

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 system enables compact design with uniform light distribution and enhanced light transmission, reducing the risk of light absorption and damage while preventing light distribution unevenness.

Implementation Method 1

an outer peripheral surface of the illumination optical system from the first surface to the second surface has a light reflecting surface on a first surface side

Methodology Applied

Scientific EffectLight reflection: Reflection

Implementation Method 2

has a light absorbing surface on a second surface side

Methodology Applied

Scientific EffectLight absorption: Absorption (EM radiation)

Implementation Method 3

the first surface has a plurality of first concave surface portions that have the same curvature radius

Methodology Applied

Scientific EffectLight refraction: Refraction

Data Source

PatentUS20260029638A1Illumination optical system and endoscope

Publication Date: 2026.01.29 FUJIFILM CORP

AI summary

An illumination optical system is disposed on an emission side of a light guide of an endoscope. In a case where a surface of the illumination optical system closest to a light guide side is defined as a first surface and a surface of the illumination optical system closest to an irradiation target side is defined as a second surface, an outer peripheral surface of the illumination optical system has a light reflecting surface on a first surface side and has a light absorbing surface on a second surface side. A stepped surface that is a surface perpendicular to an optical axis of the illumination optical system and that constitutes a step at which an outer diameter dimension changes is formed at a boundary between the light reflecting surface and the light absorbing surface. The first surface has a plurality of first concave surface portions.