Shape-Memory Objective Tube Clamping for Endoscope Lens Alignment

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Solution Overview

Problem

Current endoscope optical assemblies face challenges in meeting high-resolution image acquisition requirements due to limitations in manufacturing tolerances and mechanical precision, especially with HD and 4K technologies, as existing methods struggle to securely and accurately align optical elements.

Innovation Solution

The use of a shape memory material in the objective tube's clamping mount area, which transitions from a deformed to a trained shape when heated, providing a precise press fit for optical elements, allowing for uniform contact pressure and secure accommodation of optical elements without play, and enabling precise alignment on the optical axis.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If adhesive is used to fix optical elements in the lens tube, then the optical elements can be secured in position, but the manufacturing precision and alignment accuracy are insufficient for high-resolution image acquisition

Engineering Contradiction:
Improvealignment accuracy of optical elementsVSAvoidmanufacturing complexity
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent applies parameter changes by utilizing the phase transition temperature of shape memory material. The clamping mount is made from shape memory material that transitions from an austenite phase (at higher temperatures) to a martensite phase (at lower temperatures), enabling it to change its clamping force and internal diameter. This allows the optical elements to be inserted in the expanded state and then securely clamped when contracted, achieving high precision alignment without complex adhesive processes

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces the chemical bonding mechanism (adhesive) with a mechanical clamping mechanism based on shape memory material. The shape memory material provides elastic clamping force through its phase transition, creating a purely mechanical fixation system that achieves superior alignment precision while simplifying the manufacturing process by eliminating adhesive application steps

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

2Adaptability or versatility

If the objective tube is made rigid to maintain structural stability, then the mechanical strength is sufficient, but the tube cannot be deformed to accommodate optical elements of different sizes and shapes

Engineering Contradiction:
Improveaccommodation of different optical element sizes and shapesVSAvoidstructural stability of objective tube
Core Design Contradiction:
Adaptability or versatilityVSStrength

Solution Approach 1:

The patent applies local quality by creating different structural zones within the objective tube. The clamping mount region is made from shape memory material that can deform and adapt to different optical element geometries, while the rest of the objective tube maintains its rigid structure for overall stability. This localized flexibility allows the tube to accommodate various optical element sizes and shapes without compromising the structural integrity of the entire assembly

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent introduces dynamics by making the clamping mount region deformable through shape memory material. The tube transitions from a static rigid structure to a dynamic system where the clamping mount can expand and contract based on temperature changes. This dynamic capability enables the tube to adapt its internal diameter and cross-sectional shape to match different optical elements, providing versatility while maintaining overall structural stability

Inventive Principle:
Principle #15Dynamics

3Reliability

If the clamping force is increased to secure optical elements firmly, then the elements are held without play, but the risk of damaging the optical elements increases

Engineering Contradiction:
Improvesecure holding of optical elementsVSAvoiddamage risk to optical elements
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies dynamics by using shape memory material that can adjust its clamping force dynamically through temperature control. The material provides high clamping force when heated to the austenite phase to secure optical elements firmly without play, and can be softened by cooling to the martensite phase to reduce clamping force during insertion or adjustment. This dynamic adjustment capability allows the system to achieve reliable holding without permanent damage to optical elements

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the physical parameter of the clamping material by utilizing the phase transition of shape memory material. The clamping force is controlled by changing the temperature parameter, which transforms the material between austenite (high strength, high clamping force) and martensite (low strength, low clamping force) phases. This parameter change enables the system to apply sufficient clamping force for secure holding while avoiding excessive force that could damage delicate optical elements

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

This solution enhances the mechanical precision and manufacturing accuracy of optical assemblies, enabling high-resolution image acquisition by securely and precisely holding optical elements, accommodating elements of different sizes and shapes, and optimizing clamping forces for precise alignment on a common optical axis.

Implementation Method 1

a memory effect of the shape memory material occurring from a deformed shape to a trained shape when a memory temperature is exceeded

Methodology Applied
Scientific EffectShape memory effect: Shape Memory Alloy

Implementation Method 2

the deformable transition area between the first area and the second area, which is more easily deformable than the adjacent first and second areas of the objective tube

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3262456B1Assembly of an endoscope having a tube comprising shape-memory material for the clamp-mounting of optical elements
Publication Date: 2022.09.28 OLYMPUS WINTER & IBE GMBH
  • EP3262456B1 patent drawingFigure 1
  • EP3262456B1 patent drawingFigure 2
  • EP3262456B1 patent drawingFigure 3a~5

AI summary

The invention relates to an optical assembly (12) of an endoscope (2), an endoscope (2) comprising an optical assembly (12), a method for producing an optical assembly (12), and the use of a shape-memory material to produce an objective tube (16) of an optical assembly (12). The optical assembly (12) comprises an objective tube (16) and at least one optical element (18) held in the objective tube (16). The optical assembly (12) is developed in that the objective tube (16) comprises at least one region (26a, 26b, 26c) that acts as a clamping mount for the optical element (18), wherein said region (26a, 26b, 26c) of the objective tube (16) that acts as a clamping mount is produced of a shape-memory material at least in some segments.