Touch Display Driver Timing Control for Noise-Free Sensing

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Solution Overview

Problem

The increasing trend of electronic device thinning leads to larger coupling capacitance and mutual interference between touch and display devices, affecting display and sensing data accuracy, and noise signals further complicate this interference.

Innovation Solution

A driver circuit with a timing control circuit that determines the timing and slew rate of touch driving signals based on prohibit and noise duration signals to minimize interference, using a driver circuit with a timing control circuit and touch sensing circuit to manage signal transmission and reduce noise impact.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the electronic device is thinned to reduce size, then the device portability is improved, but the coupling capacitance between touch device and display device increases causing mutual interference

Engineering Contradiction:

Improvedevice thicknessVSAvoidcoupling capacitance interference

Core Design Contradiction:

Volume of moving objectVSObject-affected harmful factors

Solution Approach 1:

The timing control circuit proactively determines and enforces prohibit durations during which touch driving signals are suppressed, preventing interference before it occurs. This preliminary action avoids the need for post-processing of corrupted sensing data.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system implements periodic sensing operations that are synchronized with display refresh cycles. By periodically enabling touch sensing only during safe time windows and disabling it during prohibit durations, the system creates a rhythmic pattern that avoids cumulative interference while maintaining functional responsiveness.

Inventive Principle:

Principle #19Periodic action

2Speed

If touch sensing is continuously enabled to improve responsiveness, then user interaction speed is improved, but noise signals and mutual interference increase affecting sensing data accuracy

Engineering Contradiction:

Improvetouch response speedVSAvoidsensing data accuracy

Core Design Contradiction:

SpeedVSMeasurement precision

Solution Approach 1:

Touch sensing is enabled periodically during specific time windows rather than continuously. The timing control circuit creates alternating periods of sensing enablement and prohibition, allowing the system to maintain responsiveness during enabled periods while eliminating interference during prohibited periods.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The sensing enable/disable state dynamically changes based on the timing control circuit's determination of safe operating windows. Rather than a static continuous or disabled state, the system adaptively switches between states to optimize both responsiveness and accuracy under varying operational conditions.

Inventive Principle:

Principle #15Dynamics

3Reliability

If display refresh rate is increased to improve visual quality, then display performance is improved, but interference with touch sensing increases due to larger coupling capacitance

Engineering Contradiction:

Improvedisplay qualityVSAvoidmutual interference

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The timing control circuit preemptively identifies and establishes prohibit durations that align with display refresh cycles. By determining these safe windows in advance, the system ensures that touch sensing operations are never scheduled during high-interference periods, maintaining both display quality and sensing accuracy.

Inventive Principle:

Principle #10Preliminary action

4Measurement precision

If the prohibit duration is extended to reduce interference, then sensing data accuracy is improved, but the responsiveness of touch sensing decreases

Engineering Contradiction:

Improvesensing data accuracyVSAvoidtouch sensing responsiveness

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The prohibit duration is not fixed but dynamically adjusted based on real-time operational conditions. The timing control circuit determines optimal prohibit window lengths that are sufficient to eliminate interference while minimizing impact on sensing responsiveness, adapting to varying display refresh rates and touch interaction patterns.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS12487709B2Driver circuit

Publication Date: 2025.12.02 NOVATEK MICROELECTRONICS CORP

AI summary

A driver circuit, configured to drive a touch display panel, is provided. The touch display panel includes a sensor. The driver circuit includes a timing control circuit and a touch sensing circuit. The timing control circuit is configured to output a touch driving signal to the sensor. The sensor generates a sensing signal according to the touch driving signal. The touch sensing circuit is coupled to the timing control circuit and is configured to receive the sensing signal. The timing control circuit determines a timing of the touch driving signal according to a noise duration signal to drive the sensor to generate the sensing signal.