Capacitive Touch Position Detection Under Grounding Noise
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Electronic devices with touchscreens experience poor production in assembly and unstable grounding issues, leading to erratic touch inputs and inaccurate touch point calculations due to abrupt changes in capacitance data, rendering the touchscreen non-functional.
Innovation Solution
A method and apparatus for determining touch position that involves obtaining a first data matrix of capacitance data, filtering out baseline noise using preset conditions, and processing the data to obtain accurate touch point coordinates by analyzing the trigger matrix and applying centroid algorithms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional capacitive touch panel processing is used, then multi-touch input capability is achieved, but unstable grounding and assembly issues cause abrupt capacitance changes leading to inaccurate touch position determination
Solution Approach 1:
The patent applies preliminary action by calculating a trigger matrix from the first data matrix before final touch position determination. This trigger matrix serves as a pre-processing step that identifies regions of interest and filters out noise from unstable grounding, allowing the system to prepare data in advance for more accurate touch coordinate calculation.
Solution Approach 2:
The trigger matrix acts as an intermediary between the raw first data matrix and the final touch position coordinates. It mediates the data processing by highlighting significant capacitance changes while suppressing noise from grounding issues, enabling accurate touch detection despite environmental interference.
2Productivity
If complex touch algorithms are applied to process the diff matrix, then touch coordinate information is obtained, but noise from unstable grounding causes erratic touch inputs and reduces system reliability
Solution Approach 1:
The patent segments the touch processing into distinct stages: generating the first data matrix from capacitance readings, calculating the trigger matrix as an intermediate processing step, and then determining final touch coordinates. This segmentation allows noise filtering to occur at the trigger matrix stage, preventing erroneous data from propagating to the final coordinate calculation.
Solution Approach 2:
The trigger matrix extraction process isolates and removes noise components from the raw capacitance data. By identifying and extracting only the significant capacitance changes that correspond to actual touch events, the system eliminates spurious signals caused by unstable grounding while preserving genuine touch input information.
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
Improves touch input accuracy and reliability by filtering out noise caused by unstable grounding, ensuring precise touch point calculations and enhancing user experience.
Implementation Method 1
most touchscreens are capacitive touch panels (CTP), which are suitable for multi-touch input. When a user touches a capacitive touch panel, the current and capacitance values on the touch panel undergo a series of physical transformations
Data Source
AI summary
A method for determining a touch position includes receiving a touch input by a user; in response to the touch input, obtaining a first data matrix of a display, the first data matrix being a matrix including capacitance data of the display; in a case that the first data matrix meets a first preset condition, performing first processing on the first data matrix to obtain a second data matrix; and determining, based on the second data matrix, coordinate information of a touch point corresponding to the touch input. The first preset condition includes that a trigger matrix corresponding to the first data matrix meets a second preset condition, where the trigger matrix is determined based on the first data matrix.