Optical sensor for water-air detection
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Solution Overview
Problem
Existing sensors for detecting water, air, or foam are expensive to produce, have complex internal structures, and are susceptible to deposits that cause inaccurate readings.
Innovation Solution
An optical sensor with a housing containing a light interface portion comprising angled walls and light guides, where the walls' outer surfaces define an optical interface that reflects or couples light based on the medium's composition, allowing for accurate detection of water, air, and foam while being easy and inexpensive to manufacture.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a light source and light sensor are positioned on a rear side of a lens to sense medium composition, then sensing capability is improved, but manufacturing cost increases and assembly difficulty increases
Solution Approach 1:
The patent combines the light source, light sensor, and lens into a single integrated sensor unit with a unified housing structure. This merging eliminates the need for separate component assembly and reduces manufacturing complexity while maintaining the rear-side positioning arrangement for accurate medium composition sensing.
Solution Approach 2:
The sensor housing serves multiple functions simultaneously: it provides structural support, positions the optical components, and acts as part of the sensing mechanism itself. This multi-functionality reduces the number of separate components needed, lowering manufacturing costs while preserving sensing performance.
2Measurement precision
If a light source and light sensor are positioned on a rear side of a lens to sense medium composition, then sensing capability is improved, but assembly difficulty increases
Solution Approach 1:
The patent integrates the light source, light sensor, and lens into a single sensor unit with a unified housing structure. This merging eliminates the need for separate component assembly and reduces manufacturing complexity while maintaining the rear-side positioning arrangement for accurate medium composition sensing.
3Measurement precision
If sensors have a sensing surface exposed to the medium, then sensing capability is improved, but susceptibility to deposits increases
Solution Approach 1:
The patent positions the sensing surface on the rear side of the lens, away from direct contact with the medium. This dimensional repositioning allows the sensor to detect medium composition through optical interactions without the sensing surface being exposed to deposits, thus maintaining sensing capability while reducing susceptibility to contamination.
Solution Approach 2:
The lens acts as an intermediary between the sensing surface and the medium. It allows optical signals to interact with the medium for composition detection while preventing direct contact between the medium and the sensing surface, thereby eliminating deposit formation on the sensor.
4Measurement precision
If walls are positioned at an angle to detect medium composition, then detection accuracy is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent specifies a range of acceptable wall angles (60-120 degrees) rather than requiring a precise single value. This parameter change approach maintains detection accuracy across a broader angular range, reducing the stringency of manufacturing precision requirements while still achieving reliable medium composition detection.
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 sensor provides accurate detection of water, air, and foam with reduced production costs and minimized susceptibility to deposits, achieving high sensing performance with a simplified structure.
Implementation Method 1
when the sensor-external medium is air, at least a portion of the light emitted by the light emitting element is totally reflected at the outer surface of the first wall and is directed from the first wall through the cavity to the second wall and from the second wall to the light receiving element
Implementation Method 2
when the sensor-external medium is water, at least a portion of the light emitted by the light emitting element is coupled out into the sensor-external medium at the outer surface of the first wall
Data Source
AI summary
A sensor and a method of manufacture of a sensor includes a light interface portion comprising first and second walls, where a cavity is provided between the first and second walls, and where the first wall is configured such that at least a portion of light is totally reflected at the first wall when the sensor-external medium is water, and at least a portion of light is coupled out when the sensor-external medium is air, and a portion of light is coupled out and a further portion of light is totally reflected by the first wall when the sensor-external medium comprises foam. Light that is reflected by the first wall is directed toward a second wall, and reflected at the second wall to be directed to a light receiving element.