Capacitive Touch Keypad Input Filtering for Mobile Terminals
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Mobile communications terminals with touch-type keypads face issues of unintended key inputs due to the potential for excessive force application and miniaturization challenges, leading to key input errors when keys are arranged at narrow intervals.
Innovation Solution
A mobile communications terminal equipped with a touch sensor unit using capacitance sensing to detect key inputs, employing algorithms to determine the intended key by analyzing capacitance signals, setting priorities based on key positions, and adjusting sensitivity levels to prevent errors, while differentiating between normal and unintended inputs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If touch-type keys are used to reduce finger force, then ease of operation is improved, but key input errors increase due to unintended key activation
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the sensitivity threshold of the touch sensor based on the current operational context. When a key is pressed, the system modifies the capacitance detection threshold to distinguish between intentional presses and unintended contacts, thereby maintaining ease of operation while improving input accuracy
Solution Approach 2:
The system implements feedback mechanisms by continuously monitoring touch patterns and providing real-time adjustments. The controller analyzes capacitance changes and provides feedback to adjust sensitivity levels, preventing unintended key inputs while maintaining responsive operation for legitimate user actions
2Volume of moving object
If keys are arranged at narrower intervals to miniaturize the terminal, then device size is reduced, but key input errors increase due to accidental contact
Solution Approach 1:
The patent uses parameter changes by adjusting the capacitance sensitivity threshold dynamically. When keys are closely spaced, the system modifies detection parameters to differentiate between intentional key presses and accidental contacts, enabling miniaturization while maintaining input accuracy
Solution Approach 2:
The system applies preliminary action by pre-configuring sensitivity adjustment algorithms that anticipate potential input errors. Before unintended inputs can occur, the system has already established context-aware detection thresholds that prevent errors from closely spaced key arrangements
3Ease of operation
If touch sensor sensitivity is increased to detect light touches, then ease of operation is improved, but false inputs increase from unintended contacts
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the capacitance threshold based on operational context. The system increases sensitivity for intentional touches while maintaining higher thresholds to filter out false inputs from unintended contacts, resolving the contradiction between detection sensitivity and false input rate
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
Effectively reduces key input errors by accurately identifying intended keys, even when keys are closely spaced, enhancing user convenience and facilitating terminal miniaturization.
Implementation Method 1
A mobile communications terminal equipped with a touch sensor unit using capacitance sensing to detect key inputs
Data Source
Figure 1~2
Figure 3
Figure 4~5
AI summary
A mobile communications terminal and a method for preventing an input error of a key input unit are provided. The mobile communications terminal includes a touch sensor unit for sensing a key that is input by touching a keypad region in order to output a key input signal corresponding to the key and a controller adapted to determine a key input according to either a priority between multiple keys from which key signals are received or whether a received key signal was generated inadvertently.