Capacitive Electrode Layout for Distinguishing Touch and Approach
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Solution Overview
Problem
Existing capacitive sensor devices cannot reliably distinguish between an approach and a touch, and fail to detect subsequent approaches, such as a second hand, after a touch has been detected.
Innovation Solution
An electrode device with a first and second electrode structure, operating in two modes: in the first mode, a transmitting electrode emits an alternating electric field coupled to both receiving and field sensing electrodes for touch detection, and in the second mode, the receiving electrode also acts as a transmitting electrode, emitting an alternating field to the field sensing electrode for detecting further approaches.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single electrode structure is used for capacitive sensing, then the device complexity is reduced, but the ability to distinguish between approach and touch events deteriorates
Solution Approach 1:
The electrode device is divided into two distinct electrode structures: a first electrode structure with transmitting and receiving electrodes for touch detection, and a second electrode structure with field sensing electrodes for approach detection. This segmentation allows each structure to specialize in specific detection functions, enabling clear differentiation between approach and touch events while maintaining manageable overall system complexity.
2Ease of operation
If a single operation mode is used for capacitive sensing, then the operation simplicity is maintained, but the ability to detect subsequent approaches after touch deteriorates
Solution Approach 1:
The electrode device dynamically switches between two operation modes based on detection needs. In the first operation mode, the first electrode structure operates for touch detection. Upon detecting a touch event, the system transitions to the second operation mode where the second electrode structure becomes active for detecting subsequent approaches. This dynamic mode switching ensures reliable detection of multiple sequential interactions while maintaining operational simplicity through automated mode transitions.
3Use of energy by moving object
If only transmission mode is used for field coupling, then the field coupling efficiency is improved, but the ability to detect approach events deteriorates
Solution Approach 1:
The system employs periodic alternation between different operation modes. The first electrode structure operates in transmission mode during the first operation mode to efficiently couple fields for touch detection. After a touch is detected, the system periodically switches to the second operation mode where the second electrode structure uses field sensing to detect approach events. This periodic action between modes ensures both efficient field coupling and accurate approach detection at appropriate times.
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
Enables clear differentiation between touch and approach events, allowing reliable detection of subsequent approaches, improving detection precision and robustness by adjusting threshold values based on capacitive coupling.
Implementation Method 1
a first electric alternating field emitted at the transmitting electrode can be coupled to the receiving electrode and to the field sensing electrode
Implementation Method 2
the first electric signal which is tapped from the receiving electrode, and in the second operation mode, the second electric signal which is tapped from the field sensing electrode may be indicative for an approach of an object to the sensor device
Implementation Method 3
in the second operation mode, a first electric alternating field emitted at the transmitting electrode and a second electric alternating field emitted at the receiving electrode can be coupled to the field sensing electrode
Implementation Method 4
a first electric alternating field emitted at the transmitting electrode and a second electric alternating field emitted at the receiving electrode can be coupled to the field sensing electrode
Data Source
Figure 1~2b
Figure 2c~3
Figure 4a~4b
AI summary
An electrode device for a capacitive sensor device and a circuit arrangement for a capacitive sensor device for the operation of an electrode device according to the invention are provided, wherein the electrode device comprises a first electrode structure with at least one transmitting electrode and at least one receiving electrode, and a second electrode structure with at least one field sensing electrode, wherein the electrode device or the capacitive sensor device can be operated in a first operation mode and in a second operation mode. In addition a method is provided for approach and/or touch detection with a sensor device according to the invention.