Display Sync Timing for Reliable Touch and Pen Sensing

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Solution Overview

Problem

Existing electronic devices face challenges in reliably distinguishing between touch and pen inputs, leading to interference and reduced accuracy in input detection.

Innovation Solution

The electronic device employs a display layer and a sensor layer with a driving controller that adjusts the horizontal synchronization signal's period and level based on input mode, minimizing noise overlap with downlink frequencies and amplitudes to enhance input detection reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the horizontal synchronization signal uses a fixed period, then the display timing is stable, but noise frequency overlaps with downlink signal frequency causing reduced detection accuracy

Engineering Contradiction:

Improveinput detection reliabilityVSAvoidpen input detection accuracy

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The patent applies dynamics by making the horizontal synchronization signal period variable rather than fixed. The driving controller dynamically adjusts the horizontal period based on the operating mode (touch sensing mode uses first horizontal period, pen sensing mode uses second horizontal period), allowing the system to adapt timing parameters to avoid noise frequency overlap with downlink signal frequency while maintaining stable display timing in each mode.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the timing parameter (horizontal period) of the synchronization signal to resolve the frequency overlap issue. By switching between different horizontal period values depending on the sensing mode, the system alters the noise frequency characteristics to prevent overlap with the downlink signal frequency, thereby improving pen input detection accuracy without sacrificing display stability.

Inventive Principle:

Principle #35Parameter changes

2Measurement precision

If the horizontal synchronization signal period is changed to avoid noise overlap, then pen input detection accuracy improves, but display timing stability may be affected

Engineering Contradiction:

Improvepen input detection accuracyVSAvoiddisplay timing stability

Core Design Contradiction:

Measurement precisionVSStability of the object's composition

Solution Approach 1:

The patent segments the operating modes into distinct categories (touch sensing mode and pen sensing mode), each with its own optimized horizontal period setting. This segmentation allows the system to maintain stable display timing within each mode while achieving high pen input detection accuracy in the pen sensing mode, as each segment has dedicated timing parameters optimized for its specific function.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system dynamically switches between different horizontal period values based on the current operating mode. During touch sensing mode, the first horizontal period maintains display stability, while during pen sensing mode, the second horizontal period optimizes detection accuracy. This dynamic adaptation resolves the contradiction by applying different stability settings for different operational contexts.

Inventive Principle:

Principle #15Dynamics

3Reliability

If the sensor driver continuously monitors sensing signals to detect input device approach, then detection reliability improves, but power consumption increases

Engineering Contradiction:

Improveinput detection reliabilityVSAvoidsensor driver power consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The sensor driver performs periodic monitoring of sensing signals at specific intervals rather than continuous monitoring. The driver checks for input device approach at defined moments in the sensing cycle, which maintains adequate detection reliability while reducing power consumption compared to continuous monitoring. This periodic action allows the system to balance reliability and energy efficiency.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The sensor driver performs preliminary detection of input device approach before full pen sensing mode activation. This preliminary action allows the system to identify potential pen inputs early and switch to the optimized horizontal period setting in advance, maintaining high detection reliability while avoiding the need for continuous high-power monitoring throughout the entire operating cycle.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS12585357B2Electronic device and method of driving the same

Publication Date: 2026.03.24 SAMSUNG DISPLAY CO LTD

AI summary

An electronic device includes: a display layer displaying an image; a driving controller receiving an input image signal and a control signal and outputting a horizontal synchronization signal and image data; a data driving circuit configured to provide a data signal to the display layer in response to the horizontal synchronization signal and the image data; a sensor layer on the display layer; and a sensor driver driving the sensor layer and receiving sensing signals, wherein the sensor driver is configured to: output a horizontal synchronization control signal of a first level during a touch sensing mode of detecting a touch input; and output the horizontal synchronization control signal of a second level different from the first level during a pen sensing mode of detecting a pen input, and the driving controller changes a horizontal period of the horizontal synchronization signal in response to the horizontal synchronization control signal.