Touch Display Panel Shielding Layer for OLED Stylus Noise
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Solution Overview
Problem
The challenge of reducing coupling noise between the cathode and driving/sensing electrodes in large-sized OLED displays due to data signal jumps, which affects the signal-to-noise ratio and prevents the active stylus function from functioning effectively.
Innovation Solution
Incorporating a shielding layer made of conductive material, such as Ti/Al/Ti or Cu, between the display signal lines and light-emitting devices to shield interference from signal jumps, ensuring the stability of the cathode voltage and minimizing coupling noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If data signal lines are used in large-sized OLED displays, then display functionality is achieved, but coupling noise increases and signal-to-noise ratio deteriorates
Solution Approach 1:
A shielding layer is introduced as an intermediary component between the data signal lines and the cathode/driving electrodes. This shielding layer, made of conductive material and connected to a reference potential (ground or constant voltage), acts as a mediator that blocks the electromagnetic coupling between the data signal lines and the light-emitting devices, thereby reducing noise without affecting the display functionality
Solution Approach 2:
The patent converts the harmful electromagnetic field generated by data signal lines into a beneficial shielding effect. By placing the shielding layer in proximity to the data signal lines and connecting it to a reference potential, the electromagnetic field is redirected and contained, transforming the noise-generating field into a controlled shielding barrier that protects the cathode and driving electrodes from interference
2Object-affected harmful factors
If shielding layer is added between display signal lines and light-emitting devices, then coupling noise is reduced, but device complexity increases
Solution Approach 1:
The shielding layer's electrical parameter (potential) is changed to match the reference potential (ground or constant voltage), transforming it into an effective electromagnetic barrier. This parameter change enables the shielding layer to block noise without requiring complex active control circuits, maintaining structural simplicity while achieving noise reduction
Solution Approach 2:
The shielding layer is constructed using conductive materials (such as transparent conductive oxides like ITO or metal layers) that combine electrical conductivity with optical transparency. This composite material approach allows the shielding layer to simultaneously block electromagnetic noise and maintain display visibility, avoiding the need for separate noise-blocking and optical components
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 reduces coupling noise by 50%, enhancing the signal-to-noise ratio and enabling the active stylus function in large-sized OLED displays.
Implementation Method 1
a shielding layer between the plurality of display signal lines and the plurality of light-emitting devices, 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
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.