PSD Distance Detection Using Position Sensitive Detector
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Solution Overview
Problem
Traditional infrared sensors in sanitary equipment face induction malfunctions due to low reflectivity of targets, such as black clothing or hair, resulting in weak signal reception and inaccurate detection.
Innovation Solution
A distance detection induction device utilizing a Position Sensitive Detector (PSD) with a condensing lens system and precise positioning brackets to focus infrared light and measure distance, rather than relying on signal intensity, ensuring higher positioning precision and effective detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional infrared sensors use active sensing method to detect targets, then the sensing function can be realized, but the detection fails when targets have low reflectivity to infrared light
Solution Approach 1:
The patent changes the detection parameter from signal intensity (traditional infrared sensing) to position information (PSD detection). By using the Position Sensitive Detector to capture the position of the reflected infrared light spot rather than its intensity, the system can reliably detect targets with low reflectivity such as black clothing and hair, resolving the contradiction between detection reliability and signal intensity.
2Measurement precision
If PSD sensor is used to accurately survey distance through triangulation principle, then positioning precision is improved, but the device requires higher positioning precision of components
Solution Approach 1:
The patent employs self-service through automatic calibration functions and software compensation mechanisms that automatically adjust for component positioning deviations. The system includes calibration routines that detect and correct for manufacturing tolerances in lens and PSD positioning, eliminating the need for extremely high manual positioning precision while maintaining accurate distance measurement.
3Ease of operation
If the infrared emitter emits infrared light and the receiver receives reflected light, then the sensing function is achieved, but the reflected signal intensity is not strong enough for low reflectivity targets
Solution Approach 1:
The patent substitutes the traditional intensity-based detection mechanism with a position-based detection mechanism using PSD. Instead of relying on the strength of the reflected infrared signal, the system detects the position of the light spot on the PSD surface, which remains detectable even when signal intensity is very low. This substitution enables the sensing function to work effectively with low reflectivity targets without requiring stronger reflected signals.
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 device achieves reliable auto-induction in sanitary equipment by accurately determining target distance, overcoming the limitations of traditional infrared sensors with low reflectivity issues and enhancing overall induction performance.
Implementation Method 1
a condensing lens, a circuit board, an infrared light emitting means, a light receiving means for receiving and sensing the infrared light which is emitted by the infrared light emitting means and reflected by target
Implementation Method 2
The infrared light emitting means is an infrared light-emitting diode mounted on the circuit board, and emits the infrared light to the emitting lens
Implementation Method 3
the light receiving means is a distance detecting sensing module mounted on the circuit board to sense the reflected light focused by the receiving lens
Data Source
AI summary
A distance detection determination device includes positioning brackets that couple to a housing for the device. The positioning brackets include an emitting positioning bracket and a receiving positioning bracket that respectively hold and accurately position an infrared light emitter and an infrared light receiver.