Multi-touch Positioning with Interleaved Single-Layer Electrodes
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Solution Overview
Problem
Existing capacitive touch control display devices face challenges in achieving accurate multi-touch positioning with single-layer Indium Tin Oxide sensing arrays, requiring complex production processes and higher costs due to the need for multiple layers, while also struggling with non-uniform sensing effects at the edges.
Innovation Solution
A multi-touch positioning method that utilizes a single-layer capacitive touch control display device with interleaved sensing channels, each comprising a first and second sensing electrode, where touch sensing values are combined to generate a sum value, and the channel with a local maximum sum value is identified to determine touch points, allowing for accurate coordinate calculation using the center of gravity method.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a two-layer sensing array is used to achieve accurate coordinate calculation, then measurement precision is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent transforms the two-layer three-dimensional sensing array structure into a single-layer two-dimensional sensing array. By using pair triangles arranged in two dimensions within a single layer, the patent achieves equivalent or better measurement precision without the complexity of stacking multiple layers, thus resolving the contradiction between accuracy and structural complexity
Solution Approach 2:
The patent changes the geometric parameters of the sensing electrodes by using pair triangles with specific area relationships (where the area of each triangle in the pair is half of the other). This parameter optimization allows accurate coordinate calculation through capacitance ratio comparisons, achieving high precision with a simplified single-layer structure
2Ease of manufacture
If a single-layer sensing array is used to simplify production process, then manufacturing cost is reduced, but sensing accuracy deteriorates
Solution Approach 1:
The patent divides the sensing array into multiple sensing channels, each containing pair triangles that can be independently analyzed. This segmentation allows the system to process capacitance data from individual triangles and combine them to achieve accurate multi-touch positioning, maintaining high precision while using a manufacturable single-layer structure
Solution Approach 2:
The patent compensates for the reduced structural complexity of a single-layer array by introducing a two-dimensional arrangement of pair triangles within that layer. This two-dimensional configuration provides sufficient geometric information for accurate coordinate calculation, maintaining measurement precision while enabling easier manufacturing
3Device complexity
If multiple pair triangles are used to realize single-layer structure, then device complexity is reduced, but sensing uniformity worsens due to edge effects
Solution Approach 1:
The patent applies different configurations of pair triangles to different regions of the sensing array. Edge regions use pair triangles optimized for boundary detection, while central regions use configurations optimized for multi-touch detection. This local optimization ensures uniform sensing performance across the entire array, addressing edge effects while maintaining overall simplicity
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 method enhances sensing accuracy and efficiency, simplifies the production process, and expands the applicable range of touch control devices by accurately determining multi-touch points with reduced material costs and complexity.
Implementation Method 1
when a human being (object) touches the touch control display device, the human being and the sensing array form a coupling capacitor, where the sensing array is interlaced by vertical-axis (X-axis) sensing lines LA1-LAm and horizontal-axis (Y-axis) sensing lines LB1-LBn to sense capacitance changes of the coupling capacitor
Data Source
AI summary
A multi-touch positioning method for a touch control device is disclosed. The touch control device includes a plurality of sensing channels, and each of the plurality of sensing channels is interlaced by a first sensing electrode and a second sensing electrode. The multi-touch positioning method includes retrieving a first touch sensing value and a second touch sensing value respectively corresponding to the first sensing electrode and the second sensing electrode, adding the first touch sensing value and the second touch sensing value to generate a sensing sum value, determining a touch sensing channel having a local maximum value according to the plurality of sensing sum values of the plurality of sensing channels, so as to define a touch point on the touch sensing channel, and calculating a coordinate of the touch point according to the touch sensing channel and its neighboring sensing channels.