Display Device Auxiliary Electrode EMI Cancellation
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Solution Overview
Problem
Display devices with input sensors face challenges in reducing electromagnetic interference (EMI) due to unnecessary electromagnetic signals emitted by sensing electrodes, which can interfere with other devices.
Innovation Solution
The implementation of a display device with a sensing system that includes auxiliary electrodes and lines receiving inverted phase signals, which cancel out the electromagnetic signals generated by the main sensing electrodes, improving operational reliability by minimizing EMI.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If driving signal is applied to sensing electrodes to enable touch sensing, then sensing function is improved, but electromagnetic interference is generated
Solution Approach 1:
The patent applies the principle of converting harm into benefit by using the electromagnetic signals generated by sensing electrodes as a resource. Auxiliary electrodes receive inverted-phase signals that destructively interfere with the electromagnetic waves from sensing electrodes, transforming the harmful EMI into a beneficial cancellation mechanism that reduces overall electromagnetic radiation while preserving sensing functionality.
Solution Approach 2:
The patent changes the phase parameter of the signal applied to auxiliary electrodes relative to sensing electrodes. By introducing a phase inversion (180-degree phase shift) in the driving signals to auxiliary electrodes compared to sensing electrodes, the system creates destructive interference that reduces electromagnetic interference while maintaining sensing capability.
2Measurement precision
If sensing electrodes are driven at predetermined frequency to detect touch input, then input sensing capability is improved, but unnecessary electromagnetic signals are emitted
Solution Approach 1:
The patent introduces auxiliary electrodes as intermediary elements between the sensing electrodes and the external environment. These auxiliary electrodes receive inverted-phase signals that act as a mediator to cancel out the electromagnetic waves generated by sensing electrodes, thereby reducing unnecessary electromagnetic signals while preserving the touch detection function.
Solution Approach 2:
The system converts the harmful unnecessary electromagnetic signals into a beneficial cancellation mechanism. By applying inverted-phase signals to auxiliary electrodes positioned strategically, the electromagnetic waves from sensing electrodes are destructively interfered with, transforming the harmful radiation into a useful signal cancellation process.
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 enhances the sensing performance and reliability of the input sensor by effectively canceling out electromagnetic interference, ensuring smoother operation of the display device.
Implementation Method 1
When a driving signal having a predetermined frequency is applied to the sensing electrodes, electromagnetic waves according to the driving signal may be emitted
Implementation Method 2
the auxiliary unit receives an auxiliary transmission signal from the sensor controller, the auxiliary transmission signal having an inverted phase from the peripheral sensing signal
Data Source
AI summary
Disclosed is a display device. The display device includes a display panel that displays an image, an input sensor disposed on the display panel and including a sensing area and a sensing peripheral area excluding the sensing area, and a sensor controller that drives the sensing area. The input sensor includes a plurality of sensing electrodes arranged in a first direction and a second direction perpendicular to the first direction, and an auxiliary unit disposed on one side of at least one of the sensing electrodes. A main sensing electrode among the sensing electrodes receives a main sensing signal from the sensor controller, a peripheral sensing electrode adjacent to the main sensing electrode among the sensing electrodes receives a peripheral sensing signal from the sensor controller, and the auxiliary unit receives an auxiliary transmission signal having an inverted phase from the peripheral sensing signal from the sensor controller.