Passive Infrared Sensor Self-Test Using Internal Heat Source
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional self-testing techniques for passive infrared sensors only evaluate the drive circuitry and amplification circuitry, failing to detect defects in critical components like the pyroelectric material, leading to undetected issues in sensor functionality.
Innovation Solution
A device with a radiation emission component and a capture component, connected to a processor that emits and captures infrared radiation, compares the captured radiation characteristics to test characteristics, determining if the capture component is operating properly by assessing differences within a threshold quantity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional self-testing techniques measure voltage drop between terminal pins, then the drive circuitry and amplification circuitry can be evaluated, but critical sensor components such as pyroelectric material are not evaluated
Solution Approach 1:
The patent introduces a known heat source as an intermediary element to provide a controlled thermal stimulus to the pyroelectric material. This known heat source acts as a mediator between the test system and the sensor components, enabling direct evaluation of the pyroelectric material's response to thermal input, thereby detecting defects that conventional electrical testing cannot identify
Solution Approach 2:
The sensor device performs self-testing by incorporating the known heat source within the same device housing. The device tests its own pyroelectric material and capture component functionality without requiring external testing equipment, enabling autonomous defect detection of critical components including the pyroelectric material itself
2Productivity
If conventional techniques only evaluate drive circuitry and amplification circuitry, then testing is simple and quick, but defects in pyroelectric material remain undetected
Solution Approach 1:
The known heat source is positioned and configured in advance within the device housing to deliver a predetermined thermal stimulus to the pyroelectric material during self-testing. This preliminary arrangement of the heat source enables rapid testing by eliminating the need for complex external testing setups, maintaining quick testing speed while achieving comprehensive defect 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
This method allows for comprehensive self-testing of passive infrared sensors, detecting defects in pyroelectric materials and ensuring proper sensor operation, thereby improving reliability and accuracy.
Implementation Method 1
The device may emit radiation from an emission component housed in the device and capture infrared radiation at a capture component housed in the device
Implementation Method 2
Conventional self testing techniques for passive infrared sensors measure sensor operation indirectly. For example, conventional techniques apply a charge to one of two terminal pins connecting the electronic circuitry of the sensor device to pyroelectric material
Data Source
AI summary
A passive infrared sensor having a radiation capture component may be housed within a sensor device. The device may also house radiation emission components, such as light emitting diodes, in proximity to the capture component. Electronic circuitry within the device may generate a signal that causes the emission components to emit radiation that includes wavelengths in the infrared spectrum. The infrared radiation may be captured at the capture component. Characteristics of a signal generated by the capture component may be compared to test characteristics. Based on this comparison, it may be determined that the passive infrared sensor is not operating properly.