Embedded Touch Screen Self-Capacitance Electrode Integration
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Solution Overview
Problem
Existing embedded touch screens, particularly those using mutual capacitance, face high manufacturing costs and reduced accuracy due to additional process steps and shielding effects, while self-capacitance-based systems improve signal-to-noise ratio but require complex electrode arrangements.
Innovation Solution
Integrating self-capacitance electrodes into the OLED display device at existing gaps between anodes, eliminating shielding effects by opening in the cathode structure and using zigzag, step, or convex-concave shapes for adjacent electrodes to enhance sensitivity and accuracy without adding manufacturing processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If mutual capacitance principle is used for embedded touch screen, then touch function can be integrated into display device, but manufacturing cost increases due to additional masks and photolithography process steps
Solution Approach 1:
The patent merges the touch electrode layer with the pixel electrode layer into a single layer structure. The same transparent conductive layer serves dual purposes: as pixel electrodes for display and as touch electrodes for touch sensing, eliminating the need for separate touch electrode layers and reducing manufacturing complexity
Solution Approach 2:
The transparent conductive layer is designed to perform multiple functions simultaneously: it acts as both the pixel electrode for light emission control and as the touch electrode for detecting finger touches. This multi-functional design reduces the number of layers and manufacturing steps required
2Ease of manufacture
If self-capacitance electrodes are arranged in the same layer as pixel electrodes, then manufacturing process is simplified, but shielding effect from cathode reduces touch sensitivity
Solution Approach 1:
The patent segments the cathode structure by introducing openings (transparent regions) at specific positions where self-capacitance electrodes are located. This segmentation allows the electric field from touches to reach the electrodes without being blocked by the continuous cathode layer, thereby maintaining touch sensitivity while keeping the manufacturing process simple
Solution Approach 2:
The openings in the cathode structure act as intermediaries that allow the electric field to pass through from the touch surface to the self-capacitance electrodes. These openings mediate between the shielding effect of the cathode and the need for electrode detection, enabling touch sensitivity to be maintained
3Adaptability or versatility
If additional touch electrode layer is added for embedded touch screen, then touch function is achieved, but overall module thickness increases
Solution Approach 1:
The patent combines the touch electrode layer and pixel electrode layer into a single integrated layer, eliminating the need for separate touch electrode layers. This merging approach maintains full touch functionality while significantly reducing the overall thickness of the display module
4Measurement precision
If mutual capacitance electrodes are used, then touch position can be detected, but signal-to-noise ratio is lower compared to self-capacitance
Solution Approach 1:
The patent employs self-capacitance electrodes that detect touches by measuring changes in their own capacitance values when touched. Each electrode independently detects touches in its region, providing stronger signal responses and better signal-to-noise ratio compared to mutual capacitance methods that rely on interaction between separate electrode pairs
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 reduces production costs, improves touch sensitivity and accuracy by direct coupling of human body capacitance with self-capacitance electrodes, increasing signal-to-noise ratio and enabling precise touch coordinate detection.
Implementation Method 1
the self-capacitance principle is to arrange in the touch screen a plurality of self-capacitor electrodes which are arranged in the same layer and are insulated from each other. When the human body does not touch the screen, the capacitances on respective self-capacitance electrodes are of a certain fixed value; when the human body touches the screen, the capacitances on corresponding self-capacitance electrodes are of the fixed value plus the capacitance of the human body
Implementation Method 2
Organic light-emitting diode (OLED) display technology... employs the mode of self-emitting pixels instead of the common backlight mode
Implementation Method 3
OLED display technology... employs the mode of self-emitting pixels
Data Source
Figure 1
Figure 2~3
Figure 4a~4b
AI summary
The present disclosure provides an embedded touch screen comprising: an array substrate having a plurality of subpixels, each subpixel comprising an organic light-emitting diode; a plurality of gate lines and data lines arranged on the array substrate which intersect each other and are insulated from each other, the gate lines and the data lines intersecting each other to define the plurality of subpixels; a plurality of self-capacitance electrodes which are arranged in the same layer and independent from each other; and a plurality of touch connecting lines for connecting respective self-capacitance electrodes to a touch detection chip, wherein the self-capacitance electrodes may be arranged in the same layer as anodes of the organic light-emitting diodes. The present disclosure further provides a display device comprising the above embedded touch screen.