Human Body Detector Lens Array Overlap Sensitivity
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Solution Overview
Problem
Existing human body detecting devices struggle to increase sensitivity when detecting a person moving from outside to inside the detection area without impairing detection accuracy, especially due to interference from heat sources like air conditioners.
Innovation Solution
The device incorporates a pyroelectric element with multiple detecting units and a lens array that creates overlapping infrared ray reception paths, increasing the density of these paths to enhance sensitivity while maintaining detection accuracy through a signal processing circuit that outputs a voltage signal proportional to the pyroelectric element's output, allowing for improved detection of human motion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the sensitivity of the human body detecting device is increased, then the detection capability for human motion is improved, but the detection accuracy decreases due to interference from heat sources
Solution Approach 1:
The pyroelectric element is divided into multiple detecting units (first detecting unit and second detecting unit) with different polarities. Each detecting unit independently detects infrared rays, and their outputs are processed separately before being combined. This segmentation allows the system to differentiate between genuine human motion signals and interference from heat sources like air conditioners, thereby maintaining high detection capability while preserving detection accuracy.
2Reliability
If the density of infrared ray reception paths is increased, then the sensitivity is enhanced, but the complexity of the optical system increases
Solution Approach 1:
Multiple infrared ray reception paths are nested within a compact optical system structure. The lens array focuses infrared rays onto the pyroelectric element, creating overlapping reception paths that are spatially nested. This nested configuration increases the density of infrared ray reception paths and enhances sensitivity without proportionally increasing the overall system complexity, as the paths share common optical components.
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 configuration significantly raises the sensitivity of the human body detecting device while suppressing the decrease in detection accuracy, effectively detecting human motion with increased sensitivity and accuracy.
Implementation Method 1
an infrared human body detector that includes a pyroelectric element and an optical system disposed ahead of the photosensitive surface of the pyroelectric element
Implementation Method 2
The optical system includes a mirror and a lens body (a lens array). The lens body includes multiple lenses.
Data Source
Figure 1
Figure 2A~2B
Figure 3~4
AI summary
The present disclosure provides a human body detecting device capable of increasing the sensitivity. Multiple first infrared ray reception paths (71) are defined by any one of multiple lenses (30) and multiple detecting units (24). Multiple second infrared ray reception paths (72) are defined by one lens (30) adjacent to the any one of multiple lenses (30) and multiple detecting units (24). Lens array (3) is configured so that one of multiple first infrared ray reception paths (71) and one of multiple second infrared ray reception paths (72) overlap with each other. The front-side electrodes of detecting units respectively corresponding to one first infrared ray reception path (71) and one second infrared ray reception path (72) of the multiple detecting units have the same polarity.