Rod Lens Endoscope Relay System with Single Correction Doublet

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Solution Overview

Problem

Rod lens endoscopes have a high number of optical elements, leading to increased costs and unresolved aberrations such as astigmatism and field curvature, which are not corrected in symmetric systems and accumulate with each additional relay.

Innovation Solution

Implementing a relay lens system with singlet rod lenses and a single correction lens group, typically a doublet, located between the rod lenses to correct spherical and axial chromatic aberrations for the entire system, reducing the overall number of optical elements while maintaining performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple correction lens groups are used in each relay lens system, then spherical and axial chromatic aberrations are corrected, but the number of optical elements increases and cost increases

Engineering Contradiction:
Improveaberration correctionVSAvoidnumber of optical elements
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the aberration correction function from multiple relay lens systems into a single correction lens group located in one relay lens system. Specifically, a doublet correction lens group is implemented in the first relay lens system to correct spherical and axial chromatic aberrations for the entire series of relay lens systems, eliminating the need for separate correction lens groups in each relay lens system.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single doublet correction lens group serves a universal function by correcting aberrations across multiple relay lens systems simultaneously. This multi-functional approach allows one correction lens group to perform the aberration correction task that would traditionally require multiple separate correction lens groups distributed throughout the optical system.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If multiple correction lens groups are used in each relay lens system, then aberrations are corrected, but the overall cost of the optical system increases

Engineering Contradiction:
Improveaberration correctionVSAvoidcost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent combines multiple aberration correction functions into a single doublet correction lens group, reducing the total number of optical elements that need to be manufactured and assembled. This merging approach directly reduces manufacturing costs by eliminating redundant correction lens groups while maintaining comprehensive aberration correction across the entire optical system.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If symmetric rod lens systems are used, then coma, distortion, and lateral color are corrected, but astigmatism and field curvature are not corrected and accumulate with each relay

Engineering Contradiction:
Improveaberration correctionVSAvoidnumber of relays
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The doublet correction lens group acts as an intermediary element that compensates for astigmatism and field curvature aberrations accumulated from multiple relay lens systems. By positioning this correction lens group strategically in the first relay lens system, it serves as a mediator that corrects the cumulative aberrations without requiring changes to each individual relay lens system.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Reliability

If each rod lens is made as a doublet or triplet, then spherical and axial chromatic aberrations are corrected, but the number of optical elements increases

Engineering Contradiction:
Improveaberration correctionVSAvoidnumber of optical elements
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent consolidates the aberration correction function from individual rod lens doublets or triplets into a single doublet correction lens group. Instead of making each rod lens a complex multi-element assembly, the correction function is merged into one dedicated correction lens group, significantly reducing the total number of optical elements while maintaining comprehensive aberration correction.

Inventive Principle:
Principle #5Merging (Combining)

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 design reduces the number of optical elements and costs while effectively correcting aberrations, achieving performance comparable to conventional systems with fewer polished lens surfaces and maintaining image quality.

Implementation Method 1

at least one of the two rod lenses is a diffractive/refractive hybrid singlet

Methodology Applied
Scientific EffectDiffraction: Diffraction

Implementation Method 2

at least one of the two rod lenses is a diffractive/refractive hybrid singlet

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 3

a single correction lens incorporated between the two rod lenses, wherein the correction lens is a doublet lens

Methodology Applied
Scientific EffectRefraction: Refraction

Data Source

PatentEP2645147B1Compensated relays for reducing number of elements in rod lens endoscopes
Publication Date: 2018.11.21 KARL STORZ IMAGING INC
  • EP2645147B1 patent drawingFigure 1
  • EP2645147B1 patent drawingFigure 2
  • EP2645147B1 patent drawingFigure 3~4

AI summary

An endoscope and optical system for an endoscope having rod lenses and correction lens groups where the number of relay lens systems is not less than the number of correction lens groups in the endoscope and optical system of the endoscope.