Input Sensing Part Variable Frequency Driving Signal EMI Reduction
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Solution Overview
Problem
Electronic devices with display panels, such as smartphones and smart televisions, face electromagnetic interference (EMI) due to the electromagnetic signals emitted by input-sensing parts, which can disrupt the operation of other devices.
Innovation Solution
The input-sensing part includes first and second sensing electrodes with a variable frequency driving signal, where the second period is greater than or equal to the first period, and the frequency changes every frame, reducing electromagnetic interference by distributing energy across a wider frequency band.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a driving signal with a given frequency is applied to sensing electrodes, then the sensing electrodes can sense external input, but electromagnetic waves are radiated causing electromagnetic interference
Solution Approach 1:
The patent applies periodic action by using a driving signal with variable frequency that changes over time. The driving signal alternates between different frequencies in a periodic manner, which prevents continuous radiation at a single frequency and reduces electromagnetic interference while maintaining sensing capability.
Solution Approach 2:
The patent implements parameter changes by varying the frequency parameter of the driving signal applied to the sensing electrodes. By changing the frequency from a fixed value to a variable value that changes over time, the patent reduces electromagnetic interference while preserving the sensing function.
2Object-generated harmful factors
If the frequency of the driving signal is changed, then electromagnetic interference is reduced by distributing energy across a wider frequency band, but the driving signal becomes more complex
Solution Approach 1:
The patent uses periodic action to vary the driving signal frequency in a systematic manner. The frequency changes periodically over time, which reduces electromagnetic interference while following a predictable pattern that simplifies control compared to random frequency variations.
Solution Approach 2:
The patent applies dynamics by making the driving signal frequency time-dependent rather than static. The frequency parameter dynamically adjusts over time according to a predetermined pattern, allowing the system to adapt and reduce interference while maintaining manageable complexity through systematic variation.
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 solution effectively decreases electromagnetic interference by spreading the energy across a wider frequency band, minimizing noise levels and improving the operational stability of adjacent devices.
Implementation Method 1
When a driving signal with a given frequency is applied to a sensing electrode, an electromagnetic wave according to the driving signal may be radiated as an unnecessary electromagnetic signal.
Implementation Method 2
the frequency of the driving signal changes, the first period is constant, and the second period changes
Data Source
AI summary
Disclosed is an input-sensing part which includes first sensing electrodes each receiving a driving signal every frame, and second sensing electrodes insulated from the first sensing electrodes and extending to intersect the first sensing electrodes. A cycle of the driving signal is defined by a period of a first signal and a period of a second signal, which is a signal following the first signal and is lower in level than the first signal. A frequency of the driving signal is variable. When the frequency of the driving signal changes, the first period is fixed, and the second period changes.