Antenna Touch Sensing Circuit for Accurate Capacitance Detection
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Solution Overview
Problem
Existing electronic devices face challenges in accurately determining touch inputs due to calibration errors in capacitive sensors, increased manufacturing time, and inefficiencies in wearable device design, particularly with connector integration and power consumption issues.
Innovation Solution
An electronic device with a RF communication circuit, a conductive member, and a switching circuit that separates and connects a sensor to determine internal and external capacitance, allowing for improved touch detection and reduced power consumption by using a self-capacitance measuring method and optimizing sensing pad design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a capacitive sensor is calibrated by setting threshold capacitance, then sensing accuracy is improved, but manufacturing time increases and productivity degrades
Solution Approach 1:
The patent performs capacitance calibration in advance during the manufacturing process and stores the measured capacitance values in a lookup table. During actual operation, the pre-calibrated values are directly retrieved instead of performing real-time calibration, thereby eliminating the time-consuming calibration step while maintaining sensing accuracy.
Solution Approach 2:
The patent pre-calibrates the capacitive sensor by measuring capacitance values at different touch positions and storing these values in a lookup table during manufacturing. This preliminary calibration eliminates the need for time-consuming real-time calibration while maintaining sensing accuracy during operation.
2Measurement precision
If threshold capacitance is set during calibration, then sensing accuracy is improved, but operator mistakes may cause inaccurate threshold values to be set
Solution Approach 1:
The system performs self-calibration by automatically measuring capacitance values at multiple touch positions and generating the lookup table without requiring manual operator intervention. This eliminates human error in threshold setting while maintaining high sensing accuracy through automated, consistent measurement procedures.
3Measurement precision
If LEDs are turned on during detection to raise IR sensor accuracy, then recognition accuracy is improved, but additional current is consumed
Solution Approach 1:
The LEDs are activated only during the brief detection period when the IR sensor needs to measure light, rather than remaining continuously on. This periodic activation provides sufficient illumination for accurate detection while minimizing energy consumption during non-detection periods.
4Ease of manufacture
If connectors or contact terminals are added to electrically connect sensing pad and touch sensor, then electrical connection is achieved, but mounting efficiency is degraded
Solution Approach 1:
The patent integrates the electrical connection function directly into the sensing pad structure itself, eliminating the need for separate connectors or contact terminals. The sensing pad is designed to provide both mechanical support and electrical connectivity, thereby simplifying the overall structure and improving mounting efficiency.
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
Enhances touch recognition accuracy and reduces manufacturing time and power consumption, while improving mounting efficiency in wearable devices through a low-power sensor circuit and efficient sensing pad structure.
Implementation Method 1
a sensor electrically connected to the first conductive member through the switching circuit and configured to detect at least one of contact and proximity of an external object to the first conductive member
Data Source
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AI summary
An electronic device and a method are provided. The electronic device includes a first surface, a second surface opposite to the first surface, and a side surface that surrounds at least part of a space between the first and second surfaces; a Radio Frequency (RF) communication circuit; an antenna radiator that forms at least part of at least one of the first surface, the second surface, and the side surface and is connected to the RF communication circuit; a sensor that detects whether an external object contacts the antenna radiator; a switching circuit connected to the antenna radiator and the sensor; and a processor configured to receive a first value from the sensor when the antenna radiator and the sensor are connected to each other and to receive a second value from the sensor when the antenna radiator and the sensor are separated from each other.