Touch Display Data Driving Circuit Simultaneous Operation

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Solution Overview

Problem

Touch display devices face challenges in simultaneously performing display and touch sensing due to interference between display driving and touch driving, leading to decreased image quality and touch sensitivity, especially in time-division driving systems where high-resolution images are not achievable.

Innovation Solution

A touch display device with a data driving circuit that converts image digital signals into analog signals using gamma reference voltages synchronized with touch electrode driving signals, and output buffer circuits that manage data signals to minimize interference, allowing independent and simultaneous display and touch sensing operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If time-division driving is used to separately perform display and touch sensing, then interference between display and touch is reduced, but driving time for each function is insufficient and image quality decreases

Engineering Contradiction:
Improveinterference between display and touchVSAvoidimage quality
Core Design Contradiction:
Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

The patent merges display driving and touch sensing into a simultaneous operation mode where both functions are performed at the same time using the same data lines and gate lines. The data driving circuit outputs data signals while the touch driving circuit outputs touch electrode driving signals concurrently, eliminating the need for time-division multiplexing and ensuring sufficient driving time for both functions while maintaining high image quality.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent makes the data lines and gate lines universal by using them for both display driving and touch sensing simultaneously. The same physical infrastructure serves dual purposes: data lines carry both display data signals and touch sensing signals, and gate lines carry both display gate signals and touch electrode driving signals, thereby maximizing resource utilization and eliminating time-division constraints.

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

2Duration of action of moving object

If simultaneous display and touch sensing are performed using the same data lines and gate lines, then driving time is sufficient for both functions, but interference between display driving and touch driving occurs

Engineering Contradiction:
Improvedriving timeVSAvoidinterference between display and touch
Core Design Contradiction:
Duration of action of moving objectVSObject-affected harmful factors

Solution Approach 1:

The patent introduces dummy capacitors connected to data lines and dummy inductors connected to gate lines as intermediary elements. These dummy components act as mediators to absorb or compensate for interference signals generated during simultaneous operation, thereby reducing the harmful effects of interference while maintaining sufficient driving time for both display and touch functions.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the electrical parameters of the data lines and gate lines by adding dummy capacitors and inductors, respectively. This modifies the impedance characteristics and signal propagation properties of these lines, enabling them to simultaneously carry display signals and touch sensing signals with reduced mutual interference.

Inventive Principle:
Principle #35Parameter changes

3Object-affected harmful factors

If elaborate timing control is implemented for time-division driving, then display and touch sensing can be performed separately, but device complexity and cost increase

Engineering Contradiction:
Improveinterference between display and touchVSAvoidtiming control complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent combines the control functions for display and touch into a unified simultaneous operation mode. The data driving circuit and touch driving circuit operate concurrently without requiring complex timing coordination, thereby simplifying the control logic and reducing device complexity while still effectively managing interference through the use of dummy components.

Inventive Principle:
Principle #5Merging (Combining)

4Manufacturing precision

If high-resolution display is achieved through time-division driving, then image quality improves, but touch sensing time is insufficient and touch sensitivity decreases

Engineering Contradiction:
Improveimage qualityVSAvoidtouch sensitivity
Core Design Contradiction:
Manufacturing precisionVSMeasurement precision

Solution Approach 1:

The patent merges display driving and touch sensing into simultaneous operation, allowing both functions to execute at full capacity at the same time. This eliminates the time-division constraint that previously forced a trade-off between display resolution and touch sensing quality, enabling both high-resolution display and high-sensitive touch sensing to coexist.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent uses dummy capacitors and inductors as intermediary elements to mitigate interference during simultaneous high-resolution display and sensitive touch sensing operations. These dummy components ensure that the full driving time is available for both functions without compromising either image quality or touch sensitivity.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3582213B1Touch display device, data driving circuit, and driving method
Publication Date: 2023.11.01 LG DISPLAY CO LTD
  • EP3582213B1 patent drawingFigure 1
  • EP3582213B1 patent drawingFigure 2
  • EP3582213B1 patent drawingFigure 3

AI summary

A touch display device, a data driving circuit (DDC), and a driving method are provided. The touch display device, the data driving circuit (DDC), and the driving method convert an image digital signal into an image analog signal in response to a gamma reference voltage (EGBI_M) which is applied to the touch electrodes (TE) arranged in the display panel (DISP) and which is modulated in synchronization with a first touch electrode driving signal (TDS1) swinging with a first amplitude (AMP1) and output a data signal (Vdata) corresponding to the image analog signal to the data lines (DL). Accordingly, it is possible to effectively simultaneously perform display and touch sensing.