Capacitive Sensor Input Layout for Compact Wear-Free Housings
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Solution Overview
Problem
Existing sensor devices require complex production and assembly, large installation spaces, and are prone to wear and moisture issues, limiting miniaturization and increasing costs.
Innovation Solution
A sensor device with a capacitive area integrated directly on the circuit board, positioned under an actuation area in the housing, allowing for a compact, low-cost, and wear-free design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a complex contact device with elastic contact spring is used to connect sensor plate to circuit board, then electrical connection is achieved, but production complexity and assembly complexity increase
Solution Approach 1:
The sensor plate is merged with the circuit board to form a single integrated component. The capacitive sensor area is created by conductive traces directly on the circuit board, eliminating the need for separate sensor plates and complex contact devices. This integration maintains electrical connection reliability while dramatically reducing production and assembly complexity.
Solution Approach 2:
The complex contact device including elastic contact springs and separate sensor plates is extracted from the system. Instead, a simplified capacitive sensing structure is used where the circuit board itself serves as the sensing element, removing unnecessary intermediate components and simplifying the overall device architecture.
2Ease of operation
If additional sensor plate and contact device are arranged in housing recess, then capacitive sensing is enabled, but installation space requirement increases
Solution Approach 1:
The sensor plate and circuit board are merged into a single integrated structure. The capacitive sensing function is achieved through conductive traces on the circuit board itself, eliminating the need for additional sensor plates and reducing the space required in the housing.
Solution Approach 2:
The circuit board serves multiple functions: it provides structural support, electrical connections, and capacitive sensing capability. This multi-functionality eliminates the need for separate dedicated sensor plate components, thereby reducing overall housing volume requirements.
3Ease of operation
If mechanical buttons are used for input, then direct user interaction is achieved, but wear and moisture ingress issues occur
Solution Approach 1:
The mechanical button system is replaced with a capacitive sensing system. Instead of physical buttons that can wear and ingress moisture, the invention uses electrical capacitance changes detected by conductive traces on the circuit board to sense user input, providing contactless operation that is resistant to wear and environmental degradation.
Solution Approach 2:
An electric field serves as an intermediary between the user and the circuit board. The capacitive sensor detects changes in capacitance caused by the user's proximity or contact, allowing input without direct mechanical contact, thereby eliminating wear and moisture ingress issues associated with mechanical buttons.
4Ease of manufacture
If capacitive area is formed directly on circuit board, then production simplicity and compactness are achieved, but manufacturing precision requirements increase
Solution Approach 1:
The capacitive sensing structure is merged with the circuit board fabrication process. Conductive traces are created using standard PCB manufacturing techniques, integrating the sensing function into the existing circuit board production workflow and maintaining reasonable manufacturing precision requirements.
Solution Approach 2:
The capacitive sensing parameters are optimized to work with standard PCB manufacturing tolerances. By adjusting trace geometry, width, and spacing, the design achieves accurate capacitive sensing without requiring ultra-precise manufacturing, balancing ease of manufacture with sufficient measurement precision.
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 solution achieves a compact, cost-effective, and reliable sensor device with reduced spatial requirements, low energy consumption, and resistance to vibrations and corrosion.
Implementation Method 1
the second sensor array (130) comprising a capacitive area (220)
Implementation Method 2
This position is detected here for example using the Hall effect
Data Source
AI summary
A sensor device for detecting at least one physical variable, comprising a housing, at least one sensor element arranged in the housing, at least one circuit board arranged in the housing and comprising a circuit arrangement, and at least one input device arranged on the housing for carrying out input operations which are processed in the circuit arrangement to influence the sensor properties, is characterised in that the input device, to realise a touch-sensitive effect, comprises an actuation area, which is arranged on a housing wall and is permeable to electric fields, and a capacitive area, which is arranged on the circuit board or is formed as part of the circuit board, and in that the circuit board is arranged in the housing such that the capacitive area lies directly below the actuation area.