Touch Control System Using Common Electrode Current Detection

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional touch control systems require additional substrates for display, leading to increased volume, circuit complexity, and reduced detection sensitivity, especially when touch signal variations are small.

Innovation Solution

A touch control system that integrates a display circuit with a touch control circuit, utilizing an AC signal from the common electrode as a trigger signal, and includes sensor units with first and second switching elements connected in parallel, allowing for detection of current variations using a turn-off signal to enhance sensitivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If an additional display substrate is used to combine with the touch control substrate, then the display function is achieved, but the volume and circuit complexity increase

Engineering Contradiction:

Improvedisplay functionVSAvoidcircuit complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent merges the display circuit and touch control circuit into a single integrated circuit. The common electrode serves dual purposes: as part of the display circuit for liquid crystal control and as the sensing electrode for touch detection. This eliminates the need for a separate touch control substrate and reduces overall system complexity while maintaining both display and touch functionality.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The common electrode is designed to perform multiple functions simultaneously: it acts as the common electrode for the liquid crystal display and as the sensing electrode for touch control. This multi-functionality reduces the number of components needed and simplifies the overall circuit structure.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If the variation of touch control signals on the detection electrode line is small, then the system operates normally, but the touch position cannot be detected accurately

Engineering Contradiction:

Improvesystem operationVSAvoidtouch position detection accuracy

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The patent changes the detection parameter from voltage variation to current variation. By detecting current changes in the common electrode when a finger touches the screen, the system achieves higher sensitivity and more accurate touch position detection, even when signal variations are small.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent replaces the conventional voltage-based detection method with a current-based detection method. This substitution enables more sensitive detection of touch signals and improves measurement precision without compromising system reliability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Device complexity

If the touch control system uses conventional detection methods, then the system structure is simple, but the detection sensitivity is reduced

Engineering Contradiction:

Improvesystem structureVSAvoiddetection sensitivity

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent replaces conventional voltage-based detection with current-based detection by utilizing the common electrode as a sensing electrode. This substitution significantly improves detection sensitivity while maintaining relatively simple system structure, as it leverages existing components rather than adding complex new detection circuits.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 approach reduces the thickness of the touch control display panel, improves detection sensitivity, and achieves a compact, lightweight design while maintaining accurate touch position detection.

Implementation Method 1

the sensing electrode is coupled to a common electrode of the display circuit... The trigger signal is an alternating current (AC) signal, that is provided by the common electrode to the sensing electrode

Methodology Applied

Scientific EffectCapacitive coupling: Capacitance

Implementation Method 2

When a touch occurs, based on the turn-on extent of the second switch unit, the sensing electrode enables the detection electrode line to detect the variations of current signal on the sensor unit

Methodology Applied

Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentUS9083346B2Touch control system and sensing method thereof

Publication Date: 2015.07.14 GIANTPLUS TECH

AI summary

A touch control system and a sensing method thereof. Wherein, a plurality of sensor units are connected respectively to a control electrode line and a detection electrode line. Each sensor unit includes: a first switching element and a second switching element connected in parallel, and a sensing electrode connected to the second switching element. A common electrode provides a trigger signal to each sensing electrode to form coupling. The control electrode line is used to selectively output a turn-off signal in sequence to each of the first switching elements, so that the detection electrode line acts in cooperation with the sensor unit, in response to the turn-off signal. When a touch action occurs, the sensing electrode utilizes the detection electrode line to detect variations of current signal passing through the sensor unit, based on turn-on extent of the second switching element, hereby obtaining at least a touch message.