Sealed Light-Passage Proximity Sensor for Dirt-Resistant Detection
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Solution Overview
Problem
Existing proximity sensors face challenges due to their miniature size, which often results in a simplified or absent protection structure, leading to dirt accumulation and interference with sensing capabilities, causing misjudgments or signal transmission/reception failures.
Innovation Solution
A proximity sensor design featuring an enclosed accommodation space with sealed light passages made of light-transmissible materials, along with optional light shielding materials, to protect the transmitter and receiver units from dirt and provide guided light paths for accurate proximity detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the protection structure is simplified or removed to reduce the size of the product, then the size is reduced, but dirt can fall inside the product to interfere the sensing capability
Solution Approach 1:
The housing is divided into multiple enclosed accommodation spaces (transmitter accommodation space and receiver accommodation space) that are separated and isolated from each other. Each space is independently sealed with its own light passage, preventing dirt from one area from affecting the other while maintaining a compact overall structure.
Solution Approach 2:
Sealed light passages made of light-transmissible material serve as intermediaries between the external environment and the internal sensor components. These passages allow light signals to pass through while blocking dirt and contaminants from entering the accommodation spaces, thus protecting the sensing capability without requiring large protective structures.
2Ease of operation
If openings are provided for light signal transmission, then the sensing function is enabled, but dirt can enter through the openings and cause misjudgment or signal failure
Solution Approach 1:
The sealed light passages act as intermediary structures that enable light signal transmission while simultaneously preventing dirt ingress. The light-transmissible material allows optical signals to pass through the sealing structure, resolving the conflict between maintaining openings for functionality and sealing against contaminants.
Solution Approach 2:
The sealed light passages function as thin, flexible sealing structures that are transparent to light signals. These passages provide a barrier against dirt while allowing the necessary light transmission for the proximity sensing function to operate correctly.
3Reliability
If enclosed accommodation spaces with sealed light passages are provided to protect from dirt, then sensing capability is protected, but the structure becomes more complex
Solution Approach 1:
The housing structure integrates multiple functions into a single unified component: it provides structural support, creates enclosed accommodation spaces for both transmitter and receiver units, forms sealed light passages for protection and signal transmission, and blocks stray light. This merging of functions reduces the number of separate parts needed while maintaining comprehensive protection.
Solution Approach 2:
The housing is designed as a multi-functional component that simultaneously serves as a protective enclosure, a structural support, a light guide, and a stray light blocker. The sealed light passages in the housing perform multiple roles: sealing against dirt, guiding light signals, and structurally connecting different parts of the sensor assembly.
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 enclosed accommodation spaces and sealed light passages effectively prevent dirt ingress, enhance signal integrity, and improve the accuracy of proximity status determination, thereby overcoming the limitations of miniature-sized proximity sensors.
Implementation Method 1
a sealed first light passage made of a first light-transmissible material, the first light passage being provided for the light signal reflected by an object to pass through
Implementation Method 2
the housing further includes another portion made of light shielding material
Data Source
AI summary
A proximity sensor includes: a transmitter unit for transmitting a light signal; a receiver unit for receiving the light signal reflected by an object to determine a proximity status of the object; and a housing defining a first enclosed accommodation space for accommodating the receiver unit, wherein the portion of the housing which defines the first enclosed accommodation space has a sealed light passage made of a light-transmissible material such that the receiver unit is capable of receiving the light signal reflected by the object through the light passage. The housing can further include a second enclosed accommodation space for accommodating the transmitter unit.