On-Cell Touch Sensor Electrode Layout for Moire Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional touch display panels face issues with Moire fringe interference and uneven light transmission due to the arrangement of emission and receiving electrodes at different layers, leading to compromised display quality and structural fragility.
Innovation Solution
The touch display panel features a touch sensor with first, second, and third electrodes at the same layer, intersecting and connected by bridges, with an insulating layer to reduce interference and ensure uniform light transmission, and third electrodes filling blank areas for a uniform pattern.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If emission electrode and receiving electrode are arranged at different layers, then touch sensing function is achieved, but Moire fringe interference occurs and display quality deteriorates
Solution Approach 1:
The emission electrode and receiving electrode are merged into the same layer, forming a capacitive touch sensor structure where both electrodes coexist in the same plane. This eliminates the Moire fringe interference caused by multi-layer electrode arrangements while maintaining the touch sensing function through self-capacitance or mutual-capacitance detection mechanisms.
Solution Approach 2:
The patent transitions from a vertical stacking arrangement (different layers) to a planar arrangement (same layer) of electrodes. This dimensional reorganization eliminates optical interference while preserving electrical functionality through alternative electrode configuration patterns such as interdigitated or overlapping designs.
2Reliability
If emission electrode and receiving electrode are arranged at different layers, then touch sensing is enabled, but light transmission becomes uneven and display quality is impacted
Solution Approach 1:
By combining both electrodes in the same layer, the patent creates a more uniform optical path for light transmission. The planar arrangement avoids the cumulative optical interference that occurs when light passes through multiple layered electrode structures, resulting in more uniform light transmission across the display.
3Device complexity
If touch sensor is formed on inner surface of color filter substrate (In-Cell type), then integration is achieved, but production yield decreases due to complicated structure and manufacturing process
Solution Approach 1:
Instead of forming the touch sensor on the inner surface of the color filter substrate (In-Cell type), the patent inverts the approach by forming the touch sensor on the outer surface of the color filter substrate (On-Cell type). This inversion simplifies the manufacturing process and improves production yield while maintaining adequate integration level.
4Reliability
If touch sensor and cover lens are integrated (OGS type), then high touch sensitivity is achieved, but strength decreases and the structure becomes fragile
Solution Approach 1:
The patent separates the touch sensor formation from the cover lens integration, forming the touch sensor on the color filter substrate first, then adding the cover lens as a separate component. This segmentation allows the touch sensor to maintain high sensitivity while the cover lens provides structural strength and protection, avoiding the fragility issues of fully integrated OGS structures.
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 configuration minimizes light interference, enhances display quality by ensuring uniform light transmission, and stabilizes electrode connections, improving the overall appearance and durability of the touch display panel.
Implementation Method 1
the insulating layer is arranged between the second electrodes and the bridges to insulate the bridges from the second electrodes
Implementation Method 2
when light transmits through the emission electrode 241 and the receiving electrode 242, an interference phenomenon will occur separately in each of the different layers. Thus, a serious Moire fringe will be introduced
Data Source
AI summary
A touch display panel includes a TFT substrate, a CF substrate disposed above the TFT substrate, a liquid crystal layer sandwiched between the TFT substrate and the CF substrate, and a touch sensor formed on the CF substrate. The touch sensor includes a plurality of first electrodes, a plurality of second electrodes, a plurality of third electrodes, a plurality of bridges and an insulating layer. Each of the second electrodes is continuous, each of the first electrodes is interrupted by the second electrodes to form a plurality of electrode sections, and two adjacent electrode sections of the first electrode are electrically connected via a bridge. A plurality of blank areas are defined and surrounded by the first electrodes and the second electrodes, and the third electrodes are respectively disposed within the blank areas. The first electrodes, the second electrodes and the third electrodes are electrically insulated from each other.