Capacitive Touch Panel Electrode Switching for Extended Proximity Detection
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Solution Overview
Problem
Existing ultrahigh sensitivity devices face difficulties in detecting the approach of a user beyond a certain distance from a capacitive touch panel, specifically beyond 5 cm, which limits their detection range.
Innovation Solution
The input device employs a configuration of first and second electrodes arranged in a grid pattern on a substrate, with a switch that alternates between connected and disconnected states to form equipotential planar electrodes, allowing for detection of user proximity through changes in capacitance over a wider area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a multitude of sensors are mounted at locations aligned in the vertical and horizontal directions of the touch panel, then the detection sensitivity for finger approach within 5 cm is improved, but the detection range beyond 5 cm remains insufficient
Solution Approach 1:
Multiple first electrodes are electrically connected in parallel to form a single large-area detection electrode. This merging of multiple small electrodes into one large electrode extends the detection range beyond 5 cm while maintaining detection sensitivity through the combined capacitance effect of all connected electrodes.
Solution Approach 2:
The patent transitions from detecting only vertical approach (one dimension) to enabling detection in both vertical and horizontal directions by arranging electrodes in a grid pattern and connecting them to form large planar detection areas, thereby expanding the detection space to two dimensions.
2Measurement precision
If individual electrodes are used for detection, then contact location precision is improved, but the planar spread area for proximity detection is limited
Solution Approach 1:
The touch panel is divided into multiple discrete first electrodes arranged in specific directions. During contact location detection, these electrodes remain separate to provide precise spatial resolution. During proximity detection, selected electrodes are connected in parallel to form large-area equipotential electrodes, achieving wide planar spread for extended detection range.
Solution Approach 2:
The electrical connection state of the electrodes is dynamically switched between connected and disconnected states based on the detection mode required. The switch controller adjusts the electrode configuration in real-time to optimize for either contact location precision or proximity detection area according to operational needs.
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 enables the detection of user approach up to 1 meter away, effectively broadening the detection range and improving user interaction with capacitive touch panels by allowing for both contact location and proximity sensing.
Implementation Method 1
a proximity detector configured to detect approach of the user in accordance with a change in capacitance of the at least two first electrodes in the connected state
Data Source
AI summary
An input device includes first electrodes, second electrodes, a switch, and a control device. The first electrodes are spaced from one another in the vertical direction on the substrate. The second electrodes are spaced from one another in the lateral direction on the substrate. The switch switches at least some of the first electrodes between an electrically connected state and an electrically disconnected state. A contact location detector of the control device detects a contact location of a user in accordance with on a change of capacitance of each of the first electrodes and each of the second electrodes. A proximity detector of the control device detects approach of the user in accordance with a change of capacitance of at least some of the first electrodes.