Reconfigurable Touch Sensing for OLED Displays
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Solution Overview
Problem
The simplified in-cell touch sensor arrangement for PMOLED arrays suffers from low touch sensing sensitivity and accuracy due to high parasitic capacitance between anode and cathode electrodes, limiting dynamic range and requiring fixed anode electrode groupings that result in low signal-to-noise ratios and false detections, especially when fingers touch or move across multiple electrode groups.
Innovation Solution
A touch-sensing-enabled display module with a reconfigurable multiplexing and summing network (MSN) that dynamically groups and sums touch-sensing signals from anode electrodes, allowing adaptive touch sensing configurations to match graphical user interfaces, eliminating the need for additional touch sensor layers and improving signal quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a transparent touch sensor layer is added on top of the OLED display panel, then touch sensing capability is achieved, but device complexity increases and manufacturing cost increases
Solution Approach 1:
The patent combines the touch sensor function with the existing OLED display structure by using the anode electrodes as touch sensors. This merging eliminates the need for separate touch sensor layers while achieving touch sensing capability, directly resolving the contradiction between adding touch functionality and increasing device complexity
Solution Approach 2:
The anode electrodes serve dual functions: as display electrodes for OLED operation and as touch sensors for detecting finger proximity. This multi-functionality allows the same component to perform multiple roles, avoiding the need for additional dedicated touch sensor layers and reducing overall device complexity
2Device complexity
If anode electrodes are used as touch sensors in simplified in-cell arrangement, then device complexity is reduced, but touch sensing sensitivity deteriorates due to high parasitic capacitance
Solution Approach 1:
The patent implements dynamic grouping of anode electrodes where the electrode groupings can be reconfigured based on the displayed UI layout. This dynamic adaptation allows the system to optimize touch sensing performance for different interface configurations, improving sensitivity by adapting to the specific measurement requirements of each UI scenario
Solution Approach 2:
The system changes the electrical parameters of the touch sensing network by dynamically reconfiguring which anode electrodes are grouped together. By adjusting the grouping parameters based on UI layout, the system optimizes the signal-to-noise ratio and improves touch sensing sensitivity while maintaining the simplified in-cell architecture
3Device complexity
If fixed anode electrode groupings are used for touch sensing, then device complexity is reduced, but measurement precision deteriorates due to low signal-to-noise ratio when fingers touch or move across multiple electrode groups
Solution Approach 1:
The patent implements dynamic reconfiguration of anode electrode groupings based on the detected finger position and the current UI layout. When a finger touches or moves across what would traditionally be group boundaries, the system dynamically adjusts the grouping to maintain optimal signal-to-noise ratio, thereby improving measurement precision without significantly increasing device complexity
Solution Approach 2:
The system uses feedback from the touch sensing signals to dynamically adjust the electrode groupings. By monitoring the signal quality and finger position, the system can reconfigure the anode electrode groups in real-time to maintain optimal measurement precision, creating a closed-loop system that adapts to changing touch conditions
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 solution enhances touch sensing sensitivity and accuracy by dynamically reconfiguring anode electrodes to adapt to different user interface sizes and shapes, improving signal-to-noise ratios and enabling reliable detection across multiple sensors, while maintaining simplicity in integrating display drivers and touch controllers.
Implementation Method 1
the capacitive coupling between the anode electrodes 320 and the cathode electrodes 330 is still quite high
Data Source
AI summary
A touch-sensing-enabled display module is provided. In the module, a display panel has an electroluminescent layer, such as an organic light emitting diode (OLED) layer, sandwiched between cathode electrodes and anode electrodes. The anode electrodes transmit touch-sensing signals induced at the display panel. The MSN performs multiplexing and summing on the touch-sensing signals to produce output-channel signals for touch sensing. The multiplexing and the summing are reconfigurable such that the touch-sensing signals are dynamically selected for summing to produce one or more output-channel signals. A touch controller measures the output-channel signals to generate touch data. The module further includes a display driver for driving the cathode and anode electrodes. By using the MSN, the display panel is able to provide adaptive sensor reconfiguration. One particular advantage of adaptive sensor reconfiguration is that the signal-to-noise ratio of a touch signal is improved, increasing accuracy in touch detection.