Active Matrix Display Touch Detection via Reversed Electrode Structure

Solution Overview

Problem

Conventional touch display devices require additional touch detecting devices, which reduce luminance and increase hardware costs, while failing to effectively integrate image display with multi-touch detection.

Innovation Solution

An active-matrix touch display device with a reversed structure and noise-immune sensing circuit design, where the array substrate with scan and data lines is positioned closer to the user, allowing capacitive touch detection without shielding from the common electrode, and a passive-matrix device using data and scan lines for touch detection without common electrodes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If an additional touch detecting device is equipped, then touch detection function is improved, but luminance is reduced and hardware cost increases

Engineering Contradiction:

Improvetouch detection functionVSAvoidluminance

Core Design Contradiction:

Adaptability or versatilityVSIllumination intensity

Solution Approach 1:

The patent applies multi-functionality by enabling the display device's existing electrodes (data lines and scan lines) to perform both their original display functions and touch detection functions. The controller switches between display mode and touch detection mode, allowing the same hardware components to serve dual purposes, thereby eliminating the need for separate touch detection electrodes and maintaining luminance while adding touch capability.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the touch detection function with the display function by integrating the sensing capabilities into the existing display electrode structure. The data lines and scan lines that originally only carried display signals are now also used as sensing electrodes, combining two functions into a unified system that reduces hardware complexity and maintains optical performance.

Inventive Principle:

Principle #5Merging (Combining)

2Adaptability or versatility

If an additional touch detecting device is equipped, then touch detection function is improved, but hardware cost increases

Engineering Contradiction:

Improvetouch detection functionVSAvoidhardware cost

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies multi-functionality by enabling the display device's existing electrodes (data lines and scan lines) to perform both their original display functions and touch detection functions. The controller switches between display mode and touch detection mode, allowing the same hardware components to serve dual purposes, thereby eliminating the need for separate touch detection electrodes and maintaining luminance while adding touch capability.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the touch detection function with the display function by integrating the sensing capabilities into the existing display electrode structure. The data lines and scan lines that originally only carried display signals are now also used as sensing electrodes, combining two functions into a unified system that reduces hardware complexity and maintains optical performance.

Inventive Principle:

Principle #5Merging (Combining)

3Measurement precision

If common electrode is positioned closer to user, then touch detection is improved, but display structure becomes complex

Engineering Contradiction:

Improvetouch detection sensitivityVSAvoiddisplay structure

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies inversion by reversing the conventional approach: instead of placing the common electrode closer to the user for better touch detection, it positions the array substrate with data lines and scan lines closer to the user. This inverted configuration achieves effective touch detection through the conductive properties of the human body while maintaining a simpler display structure without requiring additional common electrode layers.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent applies self-service by utilizing the human body's inherent conductive properties as part of the touch detection mechanism. The user's body acts as a natural electrode, eliminating the need for complex additional sensing structures. The display device leverages the user's own conductivity to complete the detection circuit, simplifying the overall structure while maintaining detection sensitivity.

Inventive Principle:

Principle #25Self-service

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

Enables simultaneous image display and multi-touch detection with improved luminance and reduced hardware costs by utilizing the human body's conductive properties and noise-immune sensing circuits, without the need for additional touch detection devices.

Implementation Method 1

achieve the purpose of displaying images and performing multi-touch detection simultaneously

Methodology Applied

Scientific EffectCapacitive coupling: Capacitance

Data Source

PatentUS8659559B2Active and passive matrix display devices with capacitive touch detection

Publication Date: 2014.02.25 SILICON INTEGRATED SYSTEMS CORP

AI summary

A touch display apparatus is disclosed. Without additional touch device, either the reversed AM structure or a conventional PM structure is provided to combine with the human body's conductive properties and the noise-immune sensing circuit design, thereby to achieve the purpose of displaying images and performing multi-touch detection simultaneously. Thus, the hardware cost and the power consumption are reduced.