Functional Water Sensor Using Phosphor Fluorescence

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Solution Overview

Problem

Conventional ozone concentration meters are expensive and unable to achieve a compact and inexpensive design due to the use of sensitive ultraviolet photodiodes, making them unsuitable for incorporation in sterilization apparatuses that require detection of functional water concentration.

Innovation Solution

A functional water concentration sensor is developed, comprising a container, a light source emitting ultraviolet light, a phosphor that emits fluorescence when excited by ultraviolet light, and a light-receiving element, with a control circuit adjusting the optical path length based on the concentration of functional water, utilizing a peak wavelength within a predetermined range specific to the functional water.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If an expensive ultraviolet-sensitive photodiode is used to detect functional water concentration, then measurement precision is improved, but device cost and size increase

Engineering Contradiction:
Improvefunctional water concentration detection accuracyVSAvoidsensor cost and size
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent introduces a phosphor substance as an intermediary between the ultraviolet light source and the light-receiving element. The phosphor converts ultraviolet light to visible light through photoluminescence, enabling the use of inexpensive visible light-sensitive photodiodes instead of expensive ultraviolet-sensitive photodiodes, thereby resolving the contradiction between measurement precision and device cost/size

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the wavelength parameter of light by using phosphor to convert ultraviolet light to visible light. This parameter transformation allows the system to use cost-effective visible light detectors while maintaining accurate concentration measurement through the relationship between visible light intensity and functional water concentration

Inventive Principle:
Principle #35Parameter changes

2Volume of moving object

If a compact sensor design is implemented, then ease of incorporation in sterilization apparatus is improved, but measurement precision may deteriorate

Engineering Contradiction:
Improvesensor sizeVSAvoidfunctional water concentration detection accuracy
Core Design Contradiction:
Volume of moving objectVSMeasurement precision

Solution Approach 1:

The phosphor intermediary enables compact design by eliminating the need for expensive ultraviolet-sensitive photodiodes, which are typically large and costly. The visible light conversion allows use of smaller, cheaper photodiodes while maintaining measurement precision through the photoluminescence relationship

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent employs a movable reflector that can change its position or orientation to dynamically adjust the optical path length. This dynamic adjustment capability allows the sensor to maintain high measurement precision across different functional water concentrations while keeping the overall sensor structure compact

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

This configuration allows for a compact and inexpensive sensor that accurately measures functional water concentration without compromising the sterilization capability of the water, enabling its use in sterilization apparatuses while maintaining the water's functional properties.

Implementation Method 1

a phosphor that emits fluorescence when excited by ultraviolet light emitted from the light source and transmitted through the container

Methodology Applied
Scientific EffectFluorescence: Fluorescence

Implementation Method 2

a first reflector that is located inside the container and reflects the ultraviolet light

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 3

a peak wavelength of the ultraviolet light emitted from the light source is in a predetermined range that includes an absorption peak specific to the functional water

Methodology Applied
Scientific EffectAbsorption (EM radiation): Absorption (EM radiation)

Data Source

PatentEP3321664B1Functional water concentration sensor
Publication Date: 2020.04.01 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP3321664B1 patent drawingFigure 1~2
  • EP3321664B1 patent drawingFigure 3~4
  • EP3321664B1 patent drawingFigure 5A~5B

AI summary

A functional water concentration sensor (1) includes: a container (40) used to contain functional water (90); a light source (10) that emits ultraviolet light (11); a phosphor (20) that emits fluorescence (21) when excited by ultraviolet light (11) emitted from the light source (10) and transmitted through the container (40); and a light-receiving element (30) that receives the fluorescence (21), wherein a peak wavelength of the ultraviolet light (11) emitted from the light source (10) is in a predetermined range that includes an absorption peak specific to the functional water (90).