Touch Display Metal Shielding Layer Noise Reduction
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Solution Overview
Problem
Touch display devices experience signal delay and noise due to electromagnetic interference between touch signals and display signals, which deteriorate image quality and touch performance, particularly as screen size increases.
Innovation Solution
A metal shielding layer is disposed between the touch electrode and the light emitting layer, with a reference signal applied to this layer to reduce noise and signal delay, and a compensation circuit is used to generate a compensated base voltage that cancels noise, improving touch performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a metal shielding layer is disposed between the touch electrode and the light emitting layer, then electromagnetic interference is reduced and noise is decreased, but device complexity increases
Solution Approach 1:
A metal shielding layer is introduced as an intermediary component between the touch electrode and the light emitting layer. This shielding layer acts as a mediator that blocks electromagnetic interference from affecting the touch signal, thereby reducing noise and improving touch performance without fundamentally changing the operational principles of the existing components.
Solution Approach 2:
The display device is segmented into distinct functional layers with the metal shielding layer positioned specifically between the touch electrode and the light emitting layer. This segmentation allows the shielding function to be isolated to a specific region where electromagnetic interference is most problematic, rather than requiring shielding throughout the entire device.
2Area of stationary object
If the screen size of the touch display device is increased, then the display area is expanded, but signal delay increases and touch performance deteriorates
Solution Approach 1:
The metal shielding layer serves as an intermediary that reduces electromagnetic noise along the touch signal transmission path. By minimizing interference-induced signal degradation, the shielding layer helps maintain signal integrity over longer transmission distances required for larger screens, thereby reducing effective signal delay and preserving touch responsiveness.
3Measurement precision
If a reference signal is applied to the metal shielding layer, then noise cancellation is improved and touch performance is enhanced, but device complexity increases
Solution Approach 1:
A reference signal is applied to the metal shielding layer to create an active noise cancellation system. The shielding layer receives this reference signal and generates a counteracting electromagnetic field that cancels out interference signals, thereby improving touch detection precision. This feedback mechanism continuously counteracts noise to maintain high touch performance.
Solution Approach 2:
The electrical parameters of the metal shielding layer are changed by applying a reference signal to it. This transforms the shielding layer from a passive electromagnetic barrier to an active noise-canceling component, enabling it to dynamically counteract interference signals and improve touch signal quality.
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 reduces electromagnetic interference, decreases signal delay, and enhances touch performance by applying the compensated base voltage to the metal shielding layer between the touch electrode and the light emitting layer.
Implementation Method 1
disposing a metal shielding layer between a touch electrode and a light emitting layer
Implementation Method 2
applying a reference signal that may be commonly used for touch driving operation and display driving operation to a metal shielding layer
Data Source
AI summary
A touch display device includes a display layer including a light emitting layer, a touch layer including a touch electrode, a metal shielding layer disposed between the light emitting layer and the touch electrode, a reference signal line electrically connected to the metal shielding layer, and a compensation circuit that supplies a reference signal through the reference signal line.