Capacitive In-Cell Touch Panel Signal Delay Reduction

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Solution Overview

Problem

Existing capacitive in-cell touch-screen panels face a signal-delay problem when using integrated gate driver circuits to output touch scan signals to touch scanning lines, leading to improper identification of touch operations due to stringent real-time requirements.

Innovation Solution

A capacitive in-cell touch-screen panel design that includes a touch scanning line implemented by at least one gate line of a TFT array substrate, a touch driver circuit connected to load touch scan signals, and driver switches within the integrated gate driver circuit to switch between touch and gate drive signals, avoiding signal delay by disconnecting the integrated gate driver circuit during touch scan signal transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If an integrated gate driver circuit (GOA) is used to provide touch scan signals to touch scanning lines, then device complexity is reduced, but signal delay occurs leading to improper touch operation identification

Engineering Contradiction:
Improvedevice complexityVSAvoidsignal delay
Core Design Contradiction:
Device complexityVSLoss of time

Solution Approach 1:

The patent segments the gate line into two functional parts: one portion connected to the integrated gate driver circuit for display scanning, and another portion connected to an external touch controller for touch scanning. This segmentation allows each portion to be optimized for its specific function, eliminating signal delay in touch operations while maintaining the compactness of integrated driving for display functions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The gate line is designed to serve dual functions: it can be driven by the integrated gate driver circuit for display scanning, or by an external touch controller for touch scanning. This multi-functionality allows the same physical structure to support both display and touch operations without requiring separate dedicated lines, thus reducing overall device complexity while avoiding signal delay issues.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Loss of time

If external touch scan signals are provided separately from the integrated gate driver circuit, then signal delay is avoided and real-time performance is improved, but device complexity increases

Engineering Contradiction:
Improvesignal delayVSAvoiddevice complexity
Core Design Contradiction:
Loss of timeVSDevice complexity

Solution Approach 1:

The patent merges the touch scanning function with the existing gate line structure of the display device. By utilizing the same gate line for both display and touch operations through different driving sources, the patent avoids adding completely separate touch scanning infrastructure, thus limiting the increase in device complexity while achieving real-time touch response.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The gate line acts as an intermediary between two different driving sources: the integrated gate driver circuit for display functions and the external touch controller for touch functions. This intermediary role allows the system to leverage existing infrastructure while incorporating external control to eliminate signal delay, balancing complexity improvement with performance enhancement.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 solution effectively reduces signal delay and ensures accurate touch operation identification by providing separate touch scan signals through a dedicated touch driver circuit, improving the real-time performance of touch scanning lines.

Implementation Method 1

coupled voltage signals that are obtained by a touch sensing line via an inductive capacitor

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

when a human body contacts the touch-screen panel, the human body electric field will act on the inductive capacitor, causing the capacitance value of the inductive capacitor to change

Methodology Applied
Scientific EffectCapacitance: Capacitance

Data Source

PatentEP2869169B1Capacitive in-cell touch-screen panel and display device
Publication Date: 2020.01.08 BOE TECHNOLOGY GROUP CO LTD
  • EP2869169B1 patent drawingFigure 1~2
  • EP2869169B1 patent drawingFigure 3

AI summary

The present invention discloses a capacitive in-cell touch-screen panel and a display device, comprising: a touch scanning line, implemented by at least one gate line of a TFT array substrate; and a touch driver circuit connected with the touch scanning line and adapted to load touch scan signals to the touch scanning line. Compared with that an existing GOA is used to provide touch scan signals to touch scanning lines of a small-sized touch-screen panel, that a separate touch driver circuit is used to provide touch scan signals to a gate line acting as a touch scanning line can avoid a signal-delay problem.