Capacitive Touch Screen Cursor Display Using Critical Capacitance Thresholds
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Portable terminals with capacitive overlay type touch screens face challenges in accurately determining the area touched, leading to misrecognition of touch locations and potential malfunction due to the limited size of the screen.
Innovation Solution
A method and system for a portable terminal that includes a touch screen with a touch sensor and a display unit, utilizing critical capacitance values to determine and display a cursor in the touched area, and perform corresponding functions based on the sensed capacitance levels, ensuring accurate touch recognition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a capacitive overlay type touch screen is used in a portable terminal, then the touch screen can be integrated with the display unit, but the limited screen size causes inaccurate touch area determination
Solution Approach 1:
The patent applies parameter changes by introducing multiple critical capacitance values (first critical value and second critical value) to differentiate between near-touch and contact states. By changing the capacitance threshold parameters, the system can accurately determine touch area despite the limited screen size, resolving the contradiction between integration and measurement precision.
2Weight of moving object
If the touch screen size is reduced for portability, then the terminal becomes more portable, but the user may misrecognize the touched area
Solution Approach 1:
The patent uses parameter changes by establishing multiple capacitance thresholds (first critical value for near-touch, second critical value for contact) that enable accurate touch area recognition even on small portable screens. This allows the system to maintain high measurement precision while preserving portability.
3Extent of automation
If capacitance change is used to detect touch area, then touch detection is enabled, but misrecognition of touch location occurs due to capacitance variation
Solution Approach 1:
The patent resolves the contradiction by introducing multiple capacitance threshold parameters (first critical value and second critical value) that enable the automatic touch detection system to accurately distinguish between near-touch and contact states, thereby maintaining both automation and measurement precision.
Solution Approach 2:
The system uses feedback by continuously monitoring capacitance changes and comparing them against stored critical values to determine touch state. This feedback mechanism allows the system to automatically adjust its interpretation of touch input based on the magnitude of capacitance change, improving touch location accuracy while maintaining automation.
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 solution enables accurate determination and display of the touched area on a capacitive overlay type touch screen, reducing user errors and ensuring proper functionality by using critical capacitance values to differentiate between touch and contact events.
Implementation Method 1
The capacitive overlay type touch screen can detect an area where touch occurs through the change of capacitance which is generated when an object that is conductive, such as the body of a user or a stylus including a dielectric substance, comes into contact with the touch screen.
Data Source
AI summary
A portable terminal including a touch screen and method for displaying a cursor thereof are provided. The method includes determining whether a capacitance is equal to or greater than a first critical value and is less than a second critical value, if the change of the capacitance is sensed in the touch screen, displaying a cursor in an area where the change of the capacitance is sensed, if the capacitance is equal to or greater than the first critical value and is less than the second critical value, and performing a function corresponding to the area where the cursor is displayed, if the capacitance sensed in the area where the cursor is displayed is equal to or greater than the second critical value.