Mesh Electrode Touch Screen Suppressing Moire
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Solution Overview
Problem
Touch screens with fine wire-shaped electrodes experience color unevenness and reduced contrast ratios due to interference with black matrix patterns on color filter substrates, especially when attached to liquid crystal panels with polarizing plates, leading to unbalanced gradation and moire patterns.
Innovation Solution
A touch screen design featuring mesh-like row and column direction wires with specific intervals and orientations, including first and second wires extending in longitudinal and lateral directions, respectively, to suppress color unevenness and maintain contrast ratios, using materials like ITO or metallic wires with multilayer structures to reduce wire resistance and enhance transmittance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If fine wire-shaped electrodes are used to increase touch panel speed and reduce resistance, then productivity and electrical conductivity are improved, but color unevenness and moire patterns occur due to interference with black matrix patterns
Solution Approach 1:
The patent transitions from linear wire-shaped electrodes to a mesh-like electrode structure with wires extending in both row and column directions. This dimensional change from 1D to 2D allows the electrodes to intersect and overlap with black matrix patterns in multiple orientations, distributing the interference effect and suppressing moire patterns while maintaining electrical conductivity for high-speed touch detection.
Solution Approach 2:
The patent employs a composite electrode structure combining transparent conductive films (such as ITO) with fine wire-shaped electrodes in a mesh configuration. This composite approach leverages the transparency and conductivity of ITO while utilizing the low resistance of metallic wires, achieving both high productivity and reduced color unevenness through the distributed mesh pattern that minimizes interference with any single black matrix pattern orientation.
2Object-generated harmful factors
If fine wire-shaped electrodes overlap with black matrix patterns to suppress moire, then visual appearance is improved, but gradation becomes unbalanced and color unevenness occurs
Solution Approach 1:
By creating a mesh structure with wires extending in perpendicular directions (row and column directions), the patent distributes the electrode pattern across multiple dimensions. This allows the electrodes to overlap with black matrix patterns in various orientations, preventing the formation of dominant moire patterns while maintaining balanced light transmission and gradation across the display area.
Solution Approach 2:
The mesh-like electrode structure allows different regions of the electrode pattern to interact differently with the black matrix pattern, creating local variations that average out to produce uniform overall performance. The intersecting wires create a distributed pattern where no single region dominates the interference effect, thereby maintaining gradation balance while suppressing moire.
3Illumination intensity
If wire interval is reduced to decrease wire area and increase transmittance, then transparency is improved, but detection precision may be compromised
Solution Approach 1:
The mesh structure distributes electrodes in both row and column directions, creating a two-dimensional detection network. This allows the system to maintain adequate spacing between individual wires (preserving transmittance) while achieving high detection precision through the intersecting grid pattern that provides multiple detection points across the touch surface.
Solution Approach 2:
The electrode system is segmented into multiple wire segments arranged in a mesh pattern, with each wire segment contributing to the overall detection capability. This segmentation allows individual wires to be spaced sufficiently far apart to maintain high light transmittance, while the collective array of segmented wires provides sufficient detection resolution for precise touch positioning.
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
The design effectively balances gradation, suppresses color unevenness, and maintains high contrast ratios, even under varying light conditions and when attached to liquid crystal panels, while forming a wide detectable area with minimal wire area.
Implementation Method 1
a detection circuit detects an electrostatic capacitance formed between an indicator such as a finger and the first series of conductive element and the second series of conductive element that are the detection wires
Implementation Method 2
detecting an electric field change between a plurality of row wires extending in a row direction and configuring a first electrode and a plurality of column wires extending in a column direction and configuring a second electrode
Data Source
AI summary
A touch screen according to the present invention includes a plurality of row direction wires and a plurality of column direction wires provided to intersect with each other through an insulating film in planar view. The plurality of row direction wires includes a mesh-like wire having a plurality of first row direction wires extending in the longitudinal direction and a plurality of second row direction wires extending in the lateral direction. The plurality of column direction wires includes a mesh-like wire having a plurality of first column direction wires extending in the longitudinal direction and a plurality of second column direction wires extending in the lateral direction, and each of the first row direction wires and each of the first column direction wires are provided at an interval of p/3 or more.