Capacitive Touch Sensing Modes for Stable Display Sensitivity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Display devices face challenges in maintaining consistent touch sensitivity due to temperature fluctuations and sensor degradation.
Innovation Solution
The display device employs first and second sensors forming capacitance, with a sensor transmitter and receiver that outputs differential signals in a first sensing mode and alternating signals in a time division manner in a second sensing mode, using fully differential and differential amplifiers, and filter circuits to maintain touch sensitivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional single-mode sensing is used, then device complexity is low, but touch sensitivity drifts due to temperature and aging
Solution Approach 1:
The patent implements dynamic sensing mode switching between first sensing mode (differential signal output) and second sensing mode (time-division multiplexed signal output) based on operational requirements. The analog front-end dynamically reconfigures signal processing paths to maintain touch sensitivity stability across different operating conditions while managing device complexity through controlled adaptability.
Solution Approach 2:
The patent changes operational parameters by switching between different sensing modes with distinct signal processing characteristics. The first sensing mode uses differential signal output for high precision, while the second sensing mode uses time-division multiplexing for baseline stabilization, allowing the system to adapt parameters to compensate for temperature and aging effects.
2Measurement precision
If differential signal processing is used for touch position detection, then measurement precision is high, but energy consumption increases
Solution Approach 1:
The patent employs periodic switching between first sensing mode (differential signal for high precision) and second sensing mode (time-division multiplexed mode for energy efficiency). By alternating between these modes, the system achieves high measurement precision when needed while reducing energy consumption during baseline stabilization periods, creating a periodic action pattern that balances precision and power usage.
Solution Approach 2:
The patent applies partial differential signal processing only when high precision is required, rather than continuously. The time-division multiplexed mode handles baseline stabilization with lower computational overhead, using excessive precision only when necessary for accurate touch position detection, thereby optimizing the balance between measurement precision and energy consumption.
3Reliability
If baseline stabilization is performed continuously, then touch sensitivity stability is maintained, but productivity decreases
Solution Approach 1:
The patent implements periodic baseline stabilization by switching between first sensing mode (for display refresh and touch detection) and second sensing mode (for baseline stabilization). This periodic action allows the system to maintain touch sensitivity stability through regular baseline updates while preserving display refresh efficiency by not continuously performing stabilization operations.
Solution Approach 2:
The patent performs preliminary baseline stabilization in the second sensing mode before returning to normal display operations in the first sensing mode. This preliminary action ensures touch sensitivity is stabilized in advance, allowing subsequent display refresh operations to proceed at full productivity without continuous interruption for stabilization.
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 approach ensures constant touch sensitivity by compensating for temperature changes and sensor deterioration, enhancing the reliability of touch input detection.
Implementation Method 1
first sensors; second sensors forming a capacitance with the first sensors
Data Source
AI summary
A display device including: first sensors; second sensors forming a capacitance with the first sensors; a sensor transmitter connected to the first sensors and configured to supply driving signals to the first sensors; and a sensor receiver connected to the second sensors and configured to receive sensing signals from the second sensors, wherein the sensor receiver includes an analog front-end connected to a (2-1)-th sensor and a (2-2)-th sensor of the second sensors, and the analog front-end is configured to output a differential signal of a (2-1)-th sensing signal from the (2-1)-th sensor and a (2-2)-th sensing signal from the (2-2)-th sensor in a first sensing mode, and output each of the (2-1)-th sensing signal and the (2-2)-th sensing signal in a time division manner in a second sensing mode.