Touch Drive Circuit Using Charge-Recycling Capacitor
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Solution Overview
Problem
The high power consumption of drive electrodes in touch screens is a significant issue, particularly due to the energy required to charge and discharge them to target voltages, which contributes to overall power consumption in electronic devices.
Innovation Solution
A drive circuit incorporating an energy storage capacitor and a switch circuit that controls the connection of the capacitor's terminals to the drive electrode and ground, allowing for the storage and recycling of charges to reduce the need for continuous power supply charging, utilizing multiple phases to manage voltage levels efficiently.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the drive electrode is continuously charged to target voltage from power supply, then the drive electrode maintains required voltage levels for touch detection, but power consumption increases significantly
Solution Approach 1:
The patent recovers charges from the drive electrode during discharge phases and stores them in the energy storage capacitor. During subsequent charge phases, these stored charges are reused to charge the drive electrode, reducing the need for continuous power supply charging and thereby lowering drive power consumption while maintaining voltage stability
Solution Approach 2:
The energy storage capacitor enables the drive electrode to serve itself by providing stored charges during charge phases. The system uses its own discharged charges, stored in the capacitor, to recharge the drive electrode, reducing dependence on external power supply and minimizing energy loss
2Measurement precision
If the drive electrode is charged to higher voltage levels, then touch detection sensitivity improves, but energy consumption increases
Solution Approach 1:
The patent recovers charges from the drive electrode after it has been used for touch detection, storing these charges in the energy storage capacitor. This recovered charge energy is then reused in subsequent cycles, allowing the drive electrode to reach required voltage levels for sensitive detection without proportionally increasing net energy consumption from the power supply
3Duration of action of stationary object
If the power supply continuously charges the drive electrode, then the drive electrode maintains operational voltage, but overall device power consumption increases
Solution Approach 1:
The energy storage capacitor ensures continuous useful action by storing charges during discharge phases and providing them during charge phases. This creates a continuous charge-recycle-charge cycle that maintains drive electrode operation without requiring continuous power supply charging, extending operational duration while reducing overall power consumption
Solution Approach 2:
The system recovers charges that would otherwise be discarded during drive electrode discharge and stores them in the energy storage capacitor. This recovered energy extends the operational duration of the drive electrode by reducing the frequency and magnitude of power supply charging required
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 reduces power consumption by minimizing the reliance on the power supply for charging the drive electrode, thereby extending the device's runtime and reducing overall energy usage.
Implementation Method 1
an energy storage capacitor comprising a first terminal and a second terminal
Data Source
AI summary
A drive circuit, a touch drive apparatus, and an electronic device are provided. The circuit comprises a first node, a second node, a ground node, a switch circuit, and an energy storage capacitor. The first node is configured to provide a first positive voltage. The second node is configured to provide a first negative voltage. The switch circuit is configured to control a first terminal of the energy storage capacitor to be selectively connected to the ground node or the drive electrode, and control a second terminal of the energy storage capacitor to be selectively connected to the ground node or the drive electrode. In one phase, the first terminal of the energy storage capacitor receives charges released from the drive electrode. In another phase, the second terminal of the energy storage capacitor charges the drive electrode using stored charges.