Integrated Touch Screen Structure with Separate Sensor Layer
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Solution Overview
Problem
Existing touch screen technologies face challenges in integrating touch sensing circuitry with display pixel stackups, leading to increased thickness and potential interference with display operations, which affects touch screen sensitivity and overall device thickness.
Innovation Solution
The integration of touch sensing circuitry with display pixel stackups using independent touch sensing and display structures, where touch circuitry is designed to be separate from display circuitry, allowing for thinner designs and improved sensitivity by minimizing capacitive coupling and optimizing signal routing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If touch sensing circuitry is integrated into display pixel stackup, then touch sensitivity is improved, but device thickness increases
Solution Approach 1:
The patent divides the display structure into separate functional layers: a display layer and a touch sensor layer. The touch sensor layer is further segmented into independent sensing elements (TX and RX electrodes) that can be selectively activated. This segmentation allows the touch sensing circuitry to be integrated into the display stackup without requiring the entire display structure to be thicker, as only the necessary sensing layers are added to the pixel stackup.
Solution Approach 2:
The patent transitions from traditional planar touch sensor designs to a multi-layered three-dimensional stackup structure. By stacking touch sensing layers (including TX electrodes, RX electrodes, and insulating layers) vertically above the display pixels, the patent achieves integrated touch sensing within the display thickness footprint, adding minimal overall thickness while enabling sophisticated touch detection capabilities.
2Measurement precision
If touch sensing circuitry is integrated into display pixel stackup, then touch sensitivity is improved, but display operations may be interfered with
Solution Approach 1:
The patent extracts the touch sensing circuitry from the display circuitry, creating independent sensing pathways. The touch sensor layer uses separate TX (transmit) and RX (receive) electrodes that are electrically isolated from the display pixel circuitry. This extraction eliminates capacitive coupling and signal interference between touch sensing and display operations, allowing both functions to operate independently and reliably within the integrated stackup.
Solution Approach 2:
The patent introduces insulating layers (such as interlayer insulators and planarization layers) as intermediaries between the display pixel circuitry and the touch sensor electrodes. These intermediary layers provide electrical isolation and mechanical decoupling, preventing signal interference while maintaining the integrated structure. The insulating layers act as mediators that allow close proximity integration without harmful electromagnetic coupling.
3Ease of manufacture
If traditional integrated touch display structure is used, then manufacturing is simplified, but structure thickness increases
Solution Approach 1:
The patent implements a nested doll structure where the touch sensor layer is nested within the display stackup. The TX and RX electrodes are positioned in different vertical layers, with insulating layers nested between them. This nested arrangement allows multiple functional layers to be stacked vertically within a compact thickness, achieving integrated touch sensing without proportionally increasing the overall structure thickness.
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 approach results in a thinner touch screen structure with enhanced sensitivity and reduced interference between touch and display functions, enabling better detection of touch and proximity events while maintaining display performance.
Implementation Method 1
a first touch sensor electrode...configured to detect the touch or proximity event
Data Source
AI summary
A touch screen is disclosed. The touch screen can comprise a substrate having a first surface upon which a touch or proximity event is to be detected, and a second surface that opposes the first surface, and a touch sensor electrode and a first display pixel including a first display pixel TFT formed on the second surface of the substrate. The first touch sensor electrode can be disposed between the second surface of the substrate and the first display pixel TFT, and the first touch sensor electrode can be configured to detect the touch or proximity event. In some examples, the substrate can comprise a TFT glass substrate. In some examples, the touch screen can comprise a first touch sensor routing electrically coupled to the first touch sensor electrode, wherein the first touch sensor routing is disposed between the second surface of the substrate and the first display pixel TFT.