Proximity Sensor with Diffraction Grating for Shiny Object Detection
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Solution Overview
Problem
Proximity sensors, such as PSD sensors, face challenges in accurately detecting shiny objects and objects in water due to spurious reflections and signal instability, leading to unreliable distance readings.
Innovation Solution
A proximity sensor system that emits optical energy in multiple spatially spaced apart beams, using a diffraction grating to split the energy, and a multi-element sensor to receive and process the reflected energy, allowing for improved object detection and valve control in water delivery systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a PSD sensor is used to detect objects, then the sensor can provide range information based on angle of reflection, but the sensor produces unreliable and unstable output when detecting shiny objects or objects in water due to spurious reflections
Solution Approach 1:
The patent divides the single optical detection beam into multiple spatially spaced apart beams using a diffraction grating. This segmentation allows the system to distinguish between spurious reflections and valid object reflections by analyzing the spatial distribution of reflected light across multiple beams, thereby improving reliability while maintaining measurement precision
Solution Approach 2:
The patent transitions from a single-beam detection system to a multi-beam system with spatial separation. By adding the spatial dimension of multiple beams arranged in an array, the system can differentiate between reflections from different directions and positions, enabling it to filter out spurious reflections from shiny surfaces or water ripples while maintaining accurate distance measurement
2Reliability
If multiple spatially spaced apart beams are emitted, then noise and instability in readings are reduced, but device complexity increases due to additional optical components
Solution Approach 1:
The diffraction grating serves multiple functions: it splits the single optical beam into multiple spatially spaced apart beams, and it also provides spatial encoding of reflection sources. This multi-functionality achieves improved reading stability without proportionally increasing device complexity, as one component accomplishes what would otherwise require multiple separate optical elements
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
Enhances the accuracy and reliability of object detection in environments with shiny or water-affected surfaces by reducing noise and instability in readings, enabling precise control of water delivery systems.
Implementation Method 1
an optical system which splits the optical energy emitted by the first optical source in the first direction along the optical axis of the illumination module into the plurality of spatially spaced apart beams of optical energy. In a variation thereof, the optical system includes a diffraction grating which splits the optical energy emitted by the first optical source
Implementation Method 2
a multi-element sensor which receives a portion of the emitted optical energy which is reflected back from the environment
Data Source
AI summary
A proximity sensor is disclosed. The proximity sensor may be incorporated as part of a water delivery device. A holder which aligns an optical source and sensor of the proximity sensor is disclosed.