Endoscope Eyepiece Filter Mounting to Reduce Ghosting

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Solution Overview

Problem

Existing filter devices between the eyepiece portion of an endoscope and the camera head suffer from ghosting due to misalignment of the filter with the cover glass, leading to increased costs with anti-reflection coatings to mitigate this issue.

Innovation Solution

A filter device with a frame and connector that uses an elastic region to press the filter parallel to the cover glass, ensuring alignment and eliminating the need for anti-reflection coatings, thereby reducing ghosting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If anti-reflection coating is provided on the cover glass and filter to reduce ghosting, then ghosting is reduced, but manufacturing cost increases

Engineering Contradiction:
ImproveghostingVSAvoidmanufacturing cost
Core Design Contradiction:
Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

The patent replaces the optical solution (anti-reflection coating) with a mechanical solution (elastic pressing mechanism). The connector uses an elastic portion to press the filter against the cover glass, ensuring parallel alignment through mechanical force rather than relying on anti-reflection coatings to reduce reflected light.

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

Solution Approach 2:

The elastic portion acts as an intermediary element between the connector and the filter. It transmits the pressing force from the connector to the filter, enabling precise positioning and parallel alignment while accommodating manufacturing tolerances and maintaining consistent contact pressure.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If the filter is not arranged parallel to the cover glass, then alignment is easier, but ghosting occurs due to reflected light

Engineering Contradiction:
Improvealignment easeVSAvoidghosting
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The elastic portion is pre-formed with a pressing structure that automatically applies force to align the filter parallel to the cover glass upon assembly. This preliminary mechanical action ensures proper alignment is achieved during the attachment process itself, eliminating the need for complex post-assembly adjustment procedures.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The elastic portion provides dynamic adaptability in the alignment system. It can deform elastically to accommodate minor variations in component dimensions while maintaining consistent pressing force, allowing the filter to self-align parallel to the cover glass through the elastic deformation and recovery of the material.

Inventive Principle:
Principle #15Dynamics

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

Provides a low-cost and compact filter device with reduced ghosting, maintaining image quality by blocking or attenuating specific wavelengths without the need for costly anti-reflection coatings.

Implementation Method 1

The connector includes an elastic region that presses the filter or the frame to an outer circumference of an effective optical path of the cover glass

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

a filter configured to attenuate light with a predetermined wavelength from emitted light emitted from a cover glass of an eyepiece portion of an endoscope

Methodology Applied
Scientific EffectOptical absorption: Absorption (EM radiation)

Data Source

PatentEP4678088A1Filter device
Publication Date: 2026.01.14 OLYMPUS MEDICAL SYST CORP
  • EP4678088A1 patent drawingFigure 1~2
  • EP4678088A1 patent drawingFigure 3~4
  • EP4678088A1 patent drawingFigure 5~6

AI summary

A filter device 30 includes a filter 31 configured to attenuate light with a predetermined wavelength from emitted light emitted through a cover glass 13 of an eyepiece portion 12 of an endoscope 10 along an optical axis O, a frame 32 configured to hold the filter 31, and a connector 33 configured to hold the frame 32, and attach the frame 32 to a camera head 20 including an image pickup device 21 configured to receive light passed through the filter 31. The connector 33 includes an elastic region 33ER that presses the filter 31 or the frame 32 to an outer circumference of an effective optical path EA of the cover glass 13 or to a circumference of the cover glass 13, in a state where the camera head 20 is attached to the eyepiece portion 12.