Capacitive Door Handle Electrode Layout for Low-Power Sensing
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Solution Overview
Problem
Existing door handles with capacitance sensors consume significant power due to the need for continuous voltage application to multiple electrodes, which is not efficient with limited vehicle battery power.
Innovation Solution
A door handle design with a single first sensor electrode and multiple second sensor electrodes, where voltage is applied only when a finger approaches, reducing power consumption by minimizing continuous electrode activation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If voltage is continuously applied to multiple sensor electrodes to enable accurate operation detection, then detection precision is improved, but power consumption increases
Solution Approach 1:
The patent implements periodic scanning of sensor electrodes instead of continuous voltage application. The controller sequentially applies voltage to different second sensor electrodes only when operation is detected by the first sensor electrode, rather than maintaining continuous voltage on all electrodes. This periodic activation significantly reduces power consumption while maintaining detection precision through the scanning mechanism.
Solution Approach 2:
The patent dynamically adjusts which electrodes are active based on detection needs. When the first sensor electrode detects operation (capacitance change), the system dynamically activates specific second sensor electrodes for coordinate detection. This dynamic switching from idle to active state optimizes the balance between detection precision and power consumption.
2Measurement precision
If multiple second sensor electrodes are activated simultaneously for coordinate detection, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent segments the coordinate detection process into sequential steps rather than simultaneous operations. The controller divides the detection task by activating one second sensor electrode at a time to detect coordinates in different directions separately. This segmentation reduces the complexity of simultaneous multi-electrode control while maintaining coordinate detection precision through systematic scanning.
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 design allows for low-power operation of the capacitance sensor by applying voltage selectively, thereby reducing overall power consumption and extending battery life.
Implementation Method 1
a capacitance sensor configured to apply a voltage to a plurality of electrodes disposed in the capacitance sensor and measure capacitances
Data Source
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AI summary
A door handle, in which a capacitance sensor configured to detect an operation body is provided, includes a substrate formed of an insulator, a first sensor electrode disposed on a surface of the substrate, a plurality of second sensor electrodes disposed on the surface of the substrate, and a controller. The number of the plurality of second sensor electrodes is greater than the number of the first sensor electrode. The controller applies a voltage to the plurality of second sensor electrodes and detects a coordinate position of the operation body, in a case where a capacitance between the operation body and the first sensor electrode is greater than or equal to a predetermined value.