Transmittance Adjusting Device for Endoscope Vessel Contrast

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Endoscope systems using narrow band imaging with blue and green light result in dark imaging and altered color reproduction, while red-light cutoff filters cause gain noise and reduced color reproduction, failing to enhance blood vessel contrast effectively.

Innovation Solution

A transmittance adjusting device with an optical filter that maintains non-zero transmittance for wavelengths beyond 500 nm and adjusts transmittance between 460 nm and 500 nm to enhance vessel contrast, ensuring color reproduction similar to visible light observation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If narrow band imaging with blue and green light is used, then blood vessel contrast is enhanced, but color reproduction is altered and imaging becomes dark

Engineering Contradiction:
Improveblood vessel contrastVSAvoidimaging brightness
Core Design Contradiction:
Measurement precisionVSIllumination intensity

Solution Approach 1:

The patent segments the spectrum into multiple wavelength bands (blue 450-490nm, cyan 490-530nm, green 530-570nm, yellow-green 570-590nm, red 610-750nm) and selectively transmits specific bands while blocking others. This segmentation allows enhancement of blood vessel contrast through targeted blue light transmission while maintaining overall imaging brightness through controlled transmission of other beneficial wavelength bands.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by creating non-uniform transmittance across the spectrum, with high transmittance (70-90%) in the blue band (450-490nm) to enhance blood vessel contrast, and moderate transmittance (30-70%) in other bands to maintain overall brightness. This localized spectral modulation optimizes both contrast enhancement and brightness preservation.

Inventive Principle:
Principle #3Local quality

2Illumination intensity

If red component cutoff filter is used, then color reproduction is improved, but gain noise occurs and white balance deteriorates

Engineering Contradiction:
Improvecolor reproduction qualityVSAvoidwhite balance stability
Core Design Contradiction:
Illumination intensityVSReliability

Solution Approach 1:

Instead of completely blocking red light components, the patent applies partial action by transmitting 30-70% of red band (610-750nm) light. This partial transmission is sufficient to maintain color reproduction quality and white balance stability while still achieving the desired contrast enhancement, avoiding the gain noise and white balance deterioration caused by complete red light cutoff.

Inventive Principle:
Principle #16Partial or excessive action

3Object-affected harmful factors

If red light transmittance is reduced to suppress halation, then color saturation is improved, but blood vessel observation is not enhanced

Engineering Contradiction:
Improvehalation suppressionVSAvoidblood vessel contrast
Core Design Contradiction:
Object-affected harmful factorsVSMeasurement precision

Solution Approach 1:

The patent segments the spectrum to distinguish between blue light (450-490nm) which enhances blood vessel contrast and red light (610-750nm) which causes halation. By transmitting blue light with high intensity (70-90%) while controlling red light transmission (30-70%), the patent achieves both blood vessel contrast enhancement and halation suppression simultaneously through spectral segmentation.

Inventive Principle:
Principle #1Segmentation

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 solution enables normal color reproduction and enhanced blood vessel contrast in endoscope images, reducing gain noise and halation, while maintaining effective vessel expression.

Implementation Method 1

transmittance characteristics with specific wavelength ranges set to the optical filter based on light absorption characteristics of hemoglobin for visible light

Methodology Applied
Scientific EffectOptical absorption: Absorption (EM radiation)

Data Source

PatentEP2457490B1Transmissivity-adjusting device, observation device and observation system
Publication Date: 2016.11.30 OLYMPUS CORPORATION(JP)
  • EP2457490B1 patent drawingFigure 1
  • EP2457490B1 patent drawingFigure 2
  • EP2457490B1 patent drawingFigure 3~4

AI summary

Using a transmittance adjusting device 32 decreasing a transmittance of at least from 460 nm to 500 nm, which is a wavelength range between a point of end P1end of a first optical absorption peak P1max of hemoglobin and a point of start P2start of a second optical absorption peak P2max of hemoglobin, to between 20% and 70% for illuminating light from an illuminating light supply section 6 or reflected light from an object, during observation of the inside of a body cavity, enhanced display of vessels with color reproduction that has no difference from that in observation under visible light, enabling color reproduction similar to that in observation under visible light and further enhanced display of vessels.