Touch Panel Electrode Layout for Uniform Capacitance Sensing
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Solution Overview
Problem
As the size of touch display devices increases, the length of touch lines increases, leading to parasitic capacitance and degradation of touch sensitivity and accuracy due to time delays in signal transmission.
Innovation Solution
The touch display device and display panel are designed with X-touch electrode lines connected through contact holes and shifted at uniform distances, forming a multi-feeding structure to reduce time delays and uniformly distribute capacitances between touch lines and electrodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the size of touch display devices is increased, then the display area is improved, but parasitic capacitance increases and touch sensitivity degrades
Solution Approach 1:
The touch line is divided into multiple segments with individual contact holes instead of a single continuous connection. This segmentation reduces the parasitic capacitance by breaking up the continuous conductive path that would otherwise accumulate capacitance along its length, while still maintaining electrical connectivity to the touch electrode.
Solution Approach 2:
Contact holes are strategically positioned at specific locations along the touch line where they connect to Y-touch electrode lines. This local optimization ensures uniform capacitance distribution at critical interaction points while allowing the overall display area to be large, addressing the harmful parasitic capacitance effect locally rather than uniformly across the entire structure.
2Area of stationary object
If the length of touch lines is increased, then the display area is improved, but signal transmission time delay increases
Solution Approach 1:
The long touch line is segmented into multiple shorter sections connected through contact holes. Each segment transmits signals over a shorter distance, reducing the cumulative time delay that would occur in a single continuous long line, while still covering the large display area.
Solution Approach 2:
The touch line structure transitions from a simple linear arrangement to a multi-dimensional configuration with vertical connections through contact holes. This allows the signal path to be optimized in three-dimensional space, reducing the effective transmission length while maintaining coverage of the large display area.
3Area of stationary object
If touch lines are arranged to cover large area, then display area is improved, but capacitance distribution uniformity deteriorates
Solution Approach 1:
Contact holes are positioned at specific strategic locations where touch lines intersect with Y-touch electrode lines. This localized arrangement ensures that capacitance values are uniform at these critical points, maintaining stable touch sensing characteristics even across a large display area where uniform natural distribution would be difficult to achieve.
Solution Approach 2:
The arrangement of contact holes and touch lines is designed to create equipotential conditions at key sensing points. By ensuring that capacitance values are equalized through the strategic placement of contact holes, the system maintains uniform electrical characteristics across different regions of the large display panel.
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 design improves touch sensitivity and accuracy by reducing signal delays and uniformly distributing capacitances, ensuring consistent touch performance across the display panel.
Implementation Method 1
parasitic capacitance due to coupling between the touch lines and the touch electrodes increases
Data Source
AI summary
A touch display device and a display panel uniformly distributing capacitances between the touch lines and the touch electrodes are provided. The device includes a display panel in which a plurality of X-touch electrodes are electrically connected to form a X-touch electrode line and a plurality of X-touch electrode lines arranged in parallel to receive a plurality of touch driving signals, and a plurality of Y-touch electrode lines to transmit a plurality of touch sensing signals, and a touch driving circuit. A plurality of X-touch lines transmit the touch driving signals connect together the plurality of X-touch electrodes constituting a same X-touch electrode line through a plurality of contact holes. Distances between at least one Y-touch electrode line and the plurality of contact holes through which the plurality of X-touch lines are electrically connected to the X-touch electrodes adjacent to the at least one Y-touch electrode line are uniform.