Dual-Sensor Capacitance Module for Temperature-Stable Wear Detection
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Solution Overview
Problem
Capacitance detection in electronic devices is affected by temperature changes, leading to inaccurate wear state detection, as temperature drift can mimic or mask the presence of a human body, causing false recognition of device wear or removal.
Innovation Solution
A capacitance detection module with a first sensing unit that touches the human skin and a second sensing unit that does not, allowing the detecting circuit to differentiate between capacitance changes caused by temperature and human touch, thereby determining the wear state based on the capacitance values of both units.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single sensing unit is used for capacitance detection, then the device structure is simple, but temperature drift causes false detection of wear state
Solution Approach 1:
The sensing unit is divided into two separate sensing units: a first sensing unit that contacts the human body and a second sensing unit that does not contact the human body. This segmentation allows the system to distinguish between capacitance changes caused by temperature drift and those caused by actual wear state, thereby improving detection accuracy while maintaining relatively simple device structure.
2Device complexity
If capacitance detection is performed without temperature compensation, then the detection circuit is simple, but temperature changes cause false recognition of device wear or removal
Solution Approach 1:
The second sensing unit acts as an intermediary that measures only temperature-induced capacitance changes without direct human body contact. By comparing the output of the first sensing unit (which experiences both temperature effects and human body contact) with the second sensing unit (which experiences only temperature effects), the system can compensate for temperature drift and improve wear state recognition accuracy without significantly complicating the detection circuit.
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 solution effectively isolates the effects of temperature on capacitance detection, ensuring accurate determination of the wear state of electronic devices, such as headphones, by using the capacitance variation between the two sensing units to distinguish between temperature changes and human skin contact.
Implementation Method 1
the self-capacitance between them also changes. The self-capacitance refers to the capacitance value between the sensor 13 and the ground unit 14
Implementation Method 2
When a human body approaches the sensor 13, an electric field between the sensor 13 and the ground unit 14 changes
Data Source
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AI summary
The present application provides a capacitance detection module, a method and an electronic device, including: a sensing module and detecting circuit; a first sensing unit is disposed on the first surface of the sensing module, and a second sensing unit is disposed on the second surface of the sensing module; the first sensing unit and the second sensing unit are respectively connected to the detecting circuit; the detecting circuit is configured to determine, according to the capacitance value of the first sensing unit and the capacitance value of the second sensing unit, the wearing state of the user to the device having the capacitance detection module. Thereby the problem that the capacitance detection is affected by temperature is avoided.