In-cell Touch Panel Sub-electrode Segmentation for Simultaneous Display and Touch

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Solution Overview

Problem

In-cell touch panels face display and touch problems due to the deficiency of time caused by driving touch and display functions in a time-division manner, leading to inefficiencies in image quality and touch detection.

Innovation Solution

An in-cell touch panel design featuring an array substrate with gate lines and a common electrode layer, where sub-electrodes are arranged to function as touch driving and common electrodes, allowing for simultaneous line-by-line scanning and signal application, enabling simultaneous display and touch operations without the limitations of time-division driving.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If touch and display functions are driven in a time-division manner, then mutual interference between touch signals and display signals is avoided, but the duration for each function is reduced causing display and touch problems

Engineering Contradiction:

Improvesignal interference avoidanceVSAvoidtouch and display interval duration

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The common electrode layer is divided into multiple sub-electrode rows, with odd rows serving as touch driving electrodes and even rows as common electrodes. This segmentation allows simultaneous touch and display operations on different rows without signal interference, resolving the contradiction between avoiding interference and maintaining sufficient operation time.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent transitions from time-division multiplexing to spatial division multiplexing by utilizing different spatial rows of sub-electrodes for touch and display functions simultaneously. This dimensional change from time to space allows both functions to operate concurrently without mutual interference.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Device complexity

If touch electrodes and display electrodes share the same common electrode layer, then device integration is improved, but signal interference between touch and display functions occurs

Engineering Contradiction:

Improveelectrode layer integrationVSAvoidsignal interference

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The common electrode layer is segmented into multiple sub-electrode rows with alternating functions (touch driving and common). This segmentation maintains the integrated structure while eliminating signal interference by assigning different functional roles to different spatial segments of the same electrode layer.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different rows of sub-electrodes within the common electrode layer are assigned different local qualities/functions: odd rows function as touch driving electrodes while even rows function as common electrodes. This local differentiation allows the integrated structure to support both functions without interference.

Inventive Principle:

Principle #3Local quality

3Measurement precision

If the common electrode layer is divided into multiple sub-electrodes for simultaneous touch and display operations, then touch detection accuracy is improved, but the control circuit complexity increases

Engineering Contradiction:

Improvetouch detection accuracyVSAvoidcontrol circuit structure

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The control circuits for touch and display functions share common control lines and switching devices. The same gate lines and common electrode signal lines are used for both touch driving and display operations, merging control resources to reduce overall circuit complexity despite the increased functionality.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

Control lines and switching devices are designed to serve multiple functions: gate lines control both display pixel electrodes and touch driving sub-electrodes, and common electrode signal lines serve both display and touch operations. This multi-functionality reduces the number of dedicated control circuits needed.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 allows for high-resolution display and touch operations without the display and touch problems associated with time-division driving, ensuring improved image quality and efficient touch detection.

Implementation Method 1

in-cell touch panels utilize mutual capacitance principle to detect touch position of a finger

Methodology Applied

Scientific EffectMutual capacitance: Capacitance

Data Source

PatentEP3217264B1In-cell touch screen and display device

Publication Date: 2021.04.28 BOE TECHNOLOGY GROUP CO LTD

Figure 1~2
Figure 3a
Figure 3b

AI summary

In an in-cell touch panel and a display device, the common electrode layer (120) in the array substrate (100) is partitioned into a plurality of sub-electrodes arranged in an array, spaced sub-electrodes in each column of sub-electrodes serve as touch driving sub-electrodes (a) constituting a touch driving electrode and sub-electrodes other than them serve as common sub-electrodes (b). During line-by-line scanning of gate lines covered by a row of sub-electrodes, the row of sub-electrodes are applied with common electrode signals, touch driving sub-electrodes in other rows of sub-electrodes are applied with touch driving signals, and common sub-electrodes in other rows of sub-electrodes are applied with common electrode signals. The in-cell touch panel can avoid various display and touch problems resulted from deficiency of time caused by time-division driving.