Touch Display Panel Shielding Layout for OLED Coupling Noise
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional touch screens face significant coupling noise issues due to data signal jumps, particularly affecting the stability of the cathode voltage and impairing the signal-to-noise ratio, especially in large-sized OLED displays, which hinders the functionality of active styluses.
Innovation Solution
A shielding layer made of conductive material, such as Ti/Al/Ti or Cu, is introduced between the display signal lines and light-emitting devices to shield interference from signal jumps, ensuring cathode voltage stability and reducing coupling noise between the cathode and touch electrodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If data signal lines are used for high-speed data transmission, then productivity and display performance are improved, but coupling noise increases and cathode voltage stability deteriorates
Solution Approach 1:
A shielding layer made of conductive material (such as ITO, Mo, Al, or their alloys) is introduced as an intermediary between the data signal lines and the cathode. This shielding layer acts as a mediator that blocks electromagnetic interference from the data signal lines, preventing coupling noise from reaching the cathode while allowing the data transmission function to operate at high speed.
Solution Approach 2:
The patent utilizes the conductive properties of the shielding layer to convert the harmful electromagnetic interference from data signal lines into a beneficial shielding effect. By grounding the shielding layer or connecting it to a reference potential, the electromagnetic fields that would otherwise cause noise are redirected and dissipated, transforming the potential harm into a protective function.
2Object-affected harmful factors
If the shielding layer is made larger to cover more signal lines, then coupling noise reduction is improved, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The shielding layer is segmented into multiple independent regions, with each segment positioned over specific data signal lines that require shielding. This segmentation allows the shielding to be applied selectively rather than uniformly across the entire display, reducing the overall complexity while maintaining effective noise reduction where most needed.
Solution Approach 2:
The shielding layer is applied with varying density and coverage based on local requirements. Areas with high-frequency data signal lines or those most susceptible to interference receive more extensive shielding, while areas with lower interference risks have reduced or no shielding. This local quality approach optimizes the balance between noise reduction and manufacturing complexity.
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 shielding layer effectively minimizes coupling noise, enhances cathode voltage stability, and improves the signal-to-noise ratio, enabling reliable active stylus functionality in large-sized OLED displays.
Implementation Method 1
A shielding layer made of conductive material, such as Ti/Al/Ti or Cu, is introduced between the display signal lines and light-emitting devices to shield interference from signal jumps
Data Source
AI summary
The embodiment of the present disclosure provides a touch display panel and a display apparatus. The touch display panel includes: a base substrate; a plurality of display signal lines on one side of the base substrate; a plurality of light-emitting devices in an array on a side of the plurality of display signal lines away from the base substrate; a touch structure on a side of the plurality of light-emitting devices away from the base substrate; and a shielding layer between the plurality of display signal lines and the plurality of light-emitting devices, wherein an orthographic projection of the shielding layer on the base substrate covers at least a part of an orthographic projection of the plurality of display signal lines on the base substrate.