Mesh Shield for Sensor Power Line EMI Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Liquid crystal display devices with touch sensors experience noise interference from high-frequency pulses, which negatively impact wireless communication in devices like smartphones.
Innovation Solution
A display device design that incorporates a mesh-shaped shield portion on the sensor power supply line, formed using the same material as third metal wires, to reduce parasitic capacitance and electromagnetic interference (EMI), while maintaining touch performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If high-frequency pulses are used for touch sensing, then touch sensitivity is improved, but noise interference increases and adversely affects wireless communication
Solution Approach 1:
A shield portion is introduced as an intermediary element between the sensor power supply line and surrounding circuits. This shield acts as a mediator that blocks electromagnetic interference from propagating to other components while allowing the high-frequency touch sensing signals to function normally. The shield portion is connected to ground potential, creating a barrier that protects wireless communication circuits from noise generated by the high-frequency pulse signals.
Solution Approach 2:
The shield portion is strategically placed only in specific regions where electromagnetic interference is most problematic. Rather than shielding the entire device, the invention applies localized shielding around the sensor power supply line and critical communication circuits. This targeted approach reduces noise interference in vulnerable areas while maintaining touch sensing performance in the display region.
2Object-affected harmful factors
If a shield portion is added to reduce EMI, then noise interference is minimized, but device complexity increases
Solution Approach 1:
The shield portion is merged with existing ground structures and power supply line configurations in the display device. Rather than adding completely separate shielding components, the invention integrates the shield into the existing circuit board layout, combining it with ground planes and power supply traces. This merging approach reduces the overall complexity increase while still providing effective EMI protection.
Solution Approach 2:
The shield portion is implemented as a thin conductive film or layer rather than bulky three-dimensional shielding structures. This thin-film approach provides effective electromagnetic interference protection while occupying minimal space and adding minimal structural complexity. The shield can be deposited as a thin conductive layer on the circuit board, maintaining device compactness.
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
The solution effectively minimizes noise from high-frequency pulses, providing an EMI countermeasure and preserving touch sensitivity by using a mesh-shaped shield covering the sensor power supply line.
Implementation Method 1
a mesh-shaped shield portion in a mesh shape on the sensor power supply line, the shield portion being formed using the same material as the third metal wires
Implementation Method 2
to reduce parasitic capacitance and electromagnetic interference (EMI)
Data Source
AI summary
A third metal wire, a common power supply line, a sensor power supply line, a selector switch 58, and a shield portion are provided. The third metal wire is provided on a first sensor electrode formed in a display region of an array substrate. The common power supply line and the sensor power supply line are provided in a peripheral region of the array substrate. The selector switch 58 is configured to supply either DC common voltage or AC sensor voltage to the first sensor electrode. The shield portion has a mesh shape. The shield portion is provided above the sensor power supply line. The shield portion is formed using the same material as the third metal wire.