Touch Sensing Display Gate Timing for Longer Touch Scan Output

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Solution Overview

Problem

Conventional touch sensing display apparatuses face challenges in increasing touch performance due to insufficient scan output time for touch sensing, as they use a conventional gate driving circuit for time division driving.

Innovation Solution

The apparatus alternates between display and touch frames, employing wider on-pulse widths for touch scan signals and shorter carry signal transfer times, with a gate driving circuit that includes a dummy stage and multiple clock phases to enhance touch sensing performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of moving object

If a conventional gate driving circuit is used for time division driving, then the display can alternate between display frame and touch frame, but the scan output time for touch sensing is insufficient

Engineering Contradiction:
Improvescan output time for touch sensingVSAvoidtouch performance
Core Design Contradiction:
Duration of action of moving objectVSProductivity

Solution Approach 1:

The gate driving circuit is divided into multiple stages (first stage, second stage, third stage) that operate independently. Each stage can be controlled by different clock signals (first clock signal, second clock signal, third clock signal) to perform different functions - display driving, touch sensing, and carry signal transfer - thereby increasing the scan output time for touch sensing without compromising display performance

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The gate driving circuit dynamically switches between different operating modes by receiving different clock signals. The circuit can transition between display frame mode and touch frame mode, and within touch frame mode, it can perform carry signal transfer and touch scan signal output in sequence, adapting the timing to maximize scan output time for touch sensing

Inventive Principle:
Principle #15Dynamics

2Reliability

If wider on-pulse widths are used for touch scan signals, then touch sensing performance is enhanced, but the carry signal transfer time increases

Engineering Contradiction:
Improvetouch sensing performanceVSAvoidcarry signal transfer time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The gate driving circuit is segmented into multiple stages that perform different functions at different times. The first stage handles display driving, the second stage handles touch sensing with wider on-pulse widths, and the third stage handles carry signal transfer. This temporal segmentation allows each function to optimize its parameters independently - touch sensing can use wider on-pulse widths while carry signal transfer uses shorter pulses

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The gate driving circuit operates in periodic cycles, alternating between display frame periods and touch frame periods. Within touch frame periods, it performs carry signal transfer followed by touch scan signal output. This periodic structure allows the circuit to repeatedly achieve sufficient scan output time for touch sensing while maintaining efficient carry signal transfer through optimized timing in each cycle

Inventive Principle:
Principle #19Periodic action

Data Source

PatentEP4407418B1Touch sensing display apparatus
Publication Date: 2026.04.08 LG DISPLAY CO LTD
  • EP4407418B1 patent drawingFigure 1
  • EP4407418B1 patent drawingFigure 2
  • EP4407418B1 patent drawingFigure 3

AI summary

A touch sensing display apparatus includes a display panel where display driving and touch sensing driving are alternately implemented and a gate driving circuit includes a stages that are sequentially activated to drive gate lines. Each stage is activated according to a display carry clock having a voltage level that changes between a gate on voltage and a gate off voltage in a display frame and output a display scan signal to the display panel during the display driving, and each stage is activated according to a touch carry clock changing between the gate on voltage and the gate off voltage in a touch frame and output a touch scan signal to the display panel. An on-pulse width of the touch carry clock is narrower than an on pulse width of the display carry clock.