Segmented Touch Electrodes Reduce Parasitic Capacitance
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Solution Overview
Problem
Integrating touch-sensing, touch-pressure sensing, and tactile feedback functionalities within display panels complicates operations and can result in visual defects due to parasitic capacitance, making it challenging to maintain display quality and panel thickness.
Innovation Solution
A configuration of segmented electrode blocks over the display area, with transparent electrode blocks connected via common signal lines, allows for both touch-sensing and display functionalities, using a lower planarization layer with thermal and chemical stability to manage signal transmission and reduce parasitic capacitance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a discrete substrate with touch-driving lines and touch-sensing lines is overlaid on the display panel, then touch-sensing functionality is provided, but the thickness and weight of the display panel increase
Solution Approach 1:
The patent merges the touch sensor substrate with the display panel substrate by integrating touch-driving lines and touch-sensing lines directly into the display panel's layer structure. This eliminates the need for a separate discrete touch panel overlay, thereby reducing overall thickness while maintaining touch-sensing functionality.
Solution Approach 2:
The display panel's conductive lines and electrodes are designed to serve dual purposes: driving display pixels and sensing touch inputs. This multi-functionality approach allows the same structural elements to provide both display and touch capabilities, eliminating redundant components and reducing thickness.
2Length of moving object
If components for touch-sensing and tactile feedback are integrated within the display panel stacks, then thickness is reduced, but operation becomes complicated and display qualities may require compromises
Solution Approach 1:
The patent segments the common electrode into multiple electrode blocks, each independently controllable for touch sensing operations. This segmentation allows selective activation of specific regions during touch sensing, reducing interference with display operations and simplifying the control logic by isolating touch and display functions into distinct operational modes.
Solution Approach 2:
The patent implements periodic switching between display mode and touch sensing mode, where the common electrode blocks are alternately activated for their respective functions. This time-division multiplexing approach allows both display and touch functionalities to operate without continuous interference, reducing operational complexity while maintaining thin profile.
3Adaptability or versatility
If conductive lines are added for touch-sensing within the display panel, then touch functionality is achieved, but parasitic capacitance increases causing visual defects
Solution Approach 1:
The patent divides the common electrode into multiple isolated electrode blocks, which reduces the total parasitic capacitance compared to a single large continuous electrode. This segmentation also allows selective activation of only the necessary electrode blocks during touch sensing, further minimizing parasitic effects and associated visual defects.
Solution Approach 2:
The patent applies different properties to different regions by making each electrode block independently controllable. This allows optimization of local capacitance characteristics in different areas of the display panel, reducing parasitic capacitance effects in regions where they would most impact display quality while maintaining touch sensitivity where needed.
Data Source
AI summary
A display of an electric device includes a plurality of separated transparent electrode blocks, which are configured to provide one or more of supplemental features such as touch recognition. Signal paths between the transparent electrode blocks and the driver for the supplemental feature are implemented with a plurality of conductive lines placed under positioned under one or more planarization layers. The conductive lines implementing the signal paths are routed across the display area, directly toward a non-display area where drive-integrated circuits are located.