Dynamic Light Scattering Particle Size Measurement Time Optimization

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Solution Overview

Problem

The dynamic light scattering method requires varying measurement times based on particle size, leading to unnecessary longer measurement times for smaller particles and inability to measure sizes less than 100 nm accurately.

Innovation Solution

A particle size measurement method and apparatus that adjusts measurement time periods based on particle size using a test measurement phase to determine optimal sampling times, reducing overall measurement time without compromising accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a fixed measurement time period is used in dynamic light scattering method, then the measurement process is simple, but the measurement time becomes unnecessarily longer for small particles

Engineering Contradiction:
Improvemeasurement process simplicityVSAvoidmeasurement time
Core Design Contradiction:
Ease of operationVSLoss of time

Solution Approach 1:

The patent applies dynamics by making the measurement time period adjustable rather than fixed. The control unit dynamically sets the measurement time period based on particle size information, allowing the system to adapt the measurement duration to match the specific requirements of different particle sizes, thereby eliminating unnecessary waiting time for small particles while maintaining adequate measurement time for larger particles.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of measurement time period from a fixed value to a variable that depends on particle size. By establishing a relationship between particle size and optimal measurement time, the system can select appropriate time periods from a plurality of predetermined options, optimizing the measurement process for different particle characteristics.

Inventive Principle:
Principle #35Parameter changes

2Loss of information

If image pickup element is used to measure particle size, then the measurement can be visualized, but particles with size of 100 nm or less cannot be measured

Engineering Contradiction:
Improvemeasurement visualizationVSAvoiddetectable particle size range
Core Design Contradiction:
Loss of informationVSMeasurement precision

Solution Approach 1:

The patent achieves universality by combining multiple measurement approaches within a single system. It integrates dynamic light scattering measurement (effective for small particles below 100 nm) with image-based measurement capabilities (effective for visualizing larger particles). The control unit automatically selects the appropriate measurement method or combines results based on particle size, making the system universally applicable across a broad particle size range.

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

3Measurement precision

If measurement time period is extended to ensure accuracy for all particle sizes, then measurement accuracy is maintained, but productivity decreases

Engineering Contradiction:
Improvemeasurement accuracyVSAvoidmeasurement throughput
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent applies partial action by measuring only what is necessary for each specific particle size. Instead of using a uniformly long measurement time for all particles, the system uses shorter measurement times for small particles where light scattering provides sufficient accuracy, and extends measurement time only for larger particles that require it for accurate measurement. This eliminates excessive measurement time for particles that don't need it.

Inventive Principle:
Principle #16Partial or excessive action

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 method significantly reduces measurement time while maintaining accuracy, enabling the measurement of smaller particle sizes by optimizing sampling periods and using a combination of test and main measurement phases.

Implementation Method 1

radiating light to particles that are present in a solution and undergoing Brownian motion, to thereby calculate a particle size based on variations in scattered light

Methodology Applied
Scientific EffectScattered light: Scattering

Implementation Method 2

particles that are present in a solution and undergoing Brownian motion

Methodology Applied
Scientific EffectBrownian motion: Brownian Motion

Data Source

PatentEP3892981B1Particle size measurement method, particle size measurement apparatus, and particle size measurement program
Publication Date: 2023.09.06 OTSUKA DENSHI CO LTD
  • EP3892981B1 patent drawingFigure 1
  • EP3892981B1 patent drawingFigure 2
  • EP3892981B1 patent drawingFigure 3

AI summary

Provided are a particle size measurement method, a particle size measurement apparatus, and a particle size measurement program in which a needless measurement time period is omitted by setting an appropriate measurement time period in accordance with a particle size to be measured. The particle size measurement method includes: a test measurement step; an autocorrelation function calculation step; a setting step of setting a part of a plurality of measurement timings set in advance as measurement timings to be used for main measurement, based on a time period required until an autocorrelation function falls below a predetermined threshold value and a preliminary time period set and added to the time period; a main measurement step of measuring a main measurement intensity of scattered light during a main measurement time period; and a particle size calculation step of calculating a particle size of a sample.