Touch Display Electrode Spacing to Suppress Moiré Patterns
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Capacitive touch display apparatuses often suffer from moiré patterns due to the interaction between touch electrode metal mesh patterns and the light-shielding structure of the display panel, leading to reduced display quality, especially when viewed at great angles or short distances.
Innovation Solution
The touch display apparatus employs touch electrodes with wire segments arranged at specific spacings, intersecting each other, and a light shielding structure with extension segments at specific angles, to suppress moiré patterns by setting the spacings between adjacent wire segments within a specific range relative to the number of pixels per inch, thereby improving display quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If metal materials are adopted for the touch electrode layer to increase transmission speed and sensing frequency, then the response speed is improved, but moiré patterns are generated reducing display quality
Solution Approach 1:
The patent applies asymmetry by setting the spacing between wire segments to be unequal in different directions. Specifically, the spacing in the first direction (SP1) is different from the spacing in the second direction (SP2), where SP1/SP2 ≠ 1. This asymmetric spacing configuration prevents the formation of regular moiré patterns by breaking the periodicity that would otherwise create visible interference patterns when the touch electrode grid aligns with the display panel's light-shielding structure.
Solution Approach 2:
The patent changes the spacing parameter between wire segments to resolve the contradiction. By defining specific spacing relationships (SP1 = B/N × pitch, SP2 = A/N × pitch, where pitch is the pixel pitch and B/N and A/N are specific ratios), the patent optimizes the geometric parameters to eliminate moiré patterns while maintaining the metal wire segment structure for high-speed signal transmission.
2Ease of manufacture
If wire segments are arranged at regular intervals to simplify manufacturing, then ease of manufacture is improved, but moiré patterns become more visible reducing display quality
Solution Approach 1:
The patent introduces asymmetry in the wire segment arrangement by defining different spacings SP1 and SP2 in different directions, where SP1 ≠ SP2. This asymmetric configuration is implemented through specific spacing formulas based on pixel pitch and integer ratios, which prevents moiré pattern formation while remaining manufacturable using standard photolithography alignment techniques.
Solution Approach 2:
The patent applies local quality by having different spacing characteristics in different regions or directions of the touch electrode pattern. The wire segments have uniform thickness and material properties, but the spacing between segments varies by direction (SP1 in first direction, SP2 in second direction), creating locally optimized spacing that prevents moiré patterns across the entire display area.
Data Source
AI summary
A touch display apparatus including a display panel and a plurality of touch electrodes is provided. The touch electrodes overlap the display panel and have a plurality of wire segments that intersect each other. A first spacing SP1 between any adjacent two of the wire segments arranged along a first direction satisfies a relationship below:0.98×(25400PPI×(B/N))≤SP1≤1.02×(25400PPI×(B/N)),where PPI is the number of pixels per inch of the display panel, B is 1.8 or 2.1, and N is 1 or a positive even number.