Sensor Housing with Optical Grid for Angle-Selective Light Detection
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Solution Overview
Problem
Existing sensor housings fail to reliably distinguish between excitation light and fluorescent light reflected from the body at varying angles of incidence, leading to signal distortion and reduced measurement accuracy.
Innovation Solution
A sensor housing with a perforated grid structure and optical filter arrangement that allows only light rays falling at a small angle of incidence to reach the photodiode, while blocking or deflecting other light rays, ensuring accurate signal detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional sensor housing without light guiding structure is used, then the device complexity is low, but the measurement precision deteriorates due to signal distortion from light at varying angles of incidence
Solution Approach 1:
The housing is segmented into multiple functional zones: an excitation light passage for LED light to reach the body, a detection passage for fluorescent light to reach the photodiode, and partition walls separating these zones. This segmentation allows independent optimization of each light path, improving measurement precision by preventing excitation light from directly reaching the detector while maintaining manageable structural complexity through modular design
Solution Approach 2:
A light guiding structure (perforated grid or microlens array) is introduced as an intermediary element between the detection passage and the optical filter. This intermediary component selectively guides fluorescent light rays at specific angles of incidence (e.g., < 17°) to the photodiode while blocking other angles, thereby improving signal detection accuracy without requiring complete redesign of the housing structure
2Measurement precision
If an optical filter is added to block excitation light, then the measurement precision improves, but the device complexity increases due to additional components
Solution Approach 1:
The optical filter is merged with the light guiding structure by forming the filter directly on the partition wall that separates the excitation and detection passages. This integration combines the filtering function with the structural partition, improving measurement precision by blocking excitation light while reducing device complexity by eliminating separate filter components and simplifying assembly
Solution Approach 2:
The partition wall serves multiple functions: it physically separates the excitation light passage from the detection passage, provides structural support for the optical filter, and acts as a mounting surface for the light guiding structure. This multi-functionality improves signal to noise ratio through effective light separation while minimizing the number of discrete components in the device
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 ensures reliable detection of fluorescent light signals independent of the angle of incidence, maintaining measurement accuracy and compact design with minimal components.
Implementation Method 1
at least one partition wall is connected to a receptacle or receiving tray formed in or on the lower housing part for an optical filter
Implementation Method 2
a circuit board with at least one light emitting diode (LED) which emits light through the lower housing part
Implementation Method 3
a marker may include a substance that can be excited to fluoresce when exposed to excitation light
Data Source
AI summary
A housing for a sensor, comprising an upper housing part and a lower housing part which, when assembled, form a receiving space suitable for receiving a circuit board with at least one LED which emits light through the lower housing part. A plurality of passages are formed in the lower housing part, each of which is separated from the others by at least one partition wall, and at least one partition wall is connected to a receptacle or receiving tray formed in or on the lower housing part for an optical filter. A structure for guiding light is formed or arranged in or on the lower housing part and oriented toward the optical filter. The housing enables a sensor to receive light signals as reliably and clearly as possible, independently of the angles of incidence of the light returning to the sensor from a human or animal body.