Grouped Sensor Electrode Phase Control for Display Touch Systems

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Solution Overview

Problem

In touch display systems, the radiation of electromagnetic waves caused by touch drive signals can interfere with peripheral receivers and affect the accuracy of touch detection, as existing technologies do not effectively manage the phase of touch drive signals across multiple common electrodes.

Innovation Solution

A display system with multiple sensor electrodes divided into groups, where a drive circuit supplies touch drive signals with different phases to each group, and a touch detection circuit performs detection based on signals received from these electrodes, reducing electromagnetic radiation by ensuring that noise from different phase signals cancels out.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If touch drive signals with the same phase are supplied to all common electrodes, then the touch detection function can be implemented, but electromagnetic radiation interferes with peripheral receivers and reduces touch detection accuracy

Engineering Contradiction:

Improvetouch detection accuracyVSAvoidelectromagnetic radiation interference

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent divides the common electrodes into multiple groups and supplies touch drive signals with different phases to each group. This segmentation of the electrode driving approach allows the electromagnetic radiation from different groups to cancel each other out, reducing overall interference while maintaining touch detection functionality.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent changes the phase parameter of the touch drive signals supplied to different common electrode groups. By varying the phase parameter (e.g., 0° for one group, 180° for another group), the electromagnetic radiation patterns change and can be made to cancel each other, thereby reducing interference without sacrificing detection accuracy.

Inventive Principle:

Principle #35Parameter changes

2Adaptability or versatility

If multiple common electrodes are used for touch detection, then the touch detection function is enabled, but electromagnetic radiation is generated that affects peripheral receivers

Engineering Contradiction:

Improvetouch detection functionVSAvoidelectromagnetic radiation

Core Design Contradiction:

Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

The patent segments the multiple common electrodes into different groups and applies different phase signals to each group. This segmentation enables the touch detection function across multiple electrodes while the opposing phases cause electromagnetic cancellation, reducing the harmful radiation effect.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent converts the harmful electromagnetic radiation from multiple common electrodes into a beneficial cancellation effect by supplying signals with opposite phases. The electromagnetic waves that would normally interfere with peripheral receivers are instead made to cancel each other out, transforming a harmful effect into a beneficial one.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Measurement precision

If touch drive signals are supplied to all common electrodes simultaneously, then comprehensive touch detection is achieved, but peak levels of electromagnetic radiation increase

Engineering Contradiction:

Improvetouch detection coverageVSAvoidpeak electromagnetic radiation levels

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent segments the simultaneous driving of all common electrodes into grouped driving with different phases. This allows comprehensive touch detection coverage across all electrodes while the phased approach reduces peak radiation levels through destructive interference of electromagnetic waves from different groups.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent employs periodic alternation of phase signals across different common electrode groups. By periodically switching phases or maintaining opposite phases in different groups, the system achieves continuous touch detection coverage while minimizing peak electromagnetic radiation through time-based or space-based phase alternation.

Inventive Principle:

Principle #19Periodic action

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 approach reduces peak levels of electromagnetic radiation and maintains touch detection accuracy by ensuring that noise from different phase signals is cancelled out, thereby improving the system's performance and reducing interference.

Implementation Method 1

the radiation of electromagnetic waves caused by touch drive signals can interfere with peripheral receivers... reducing electromagnetic radiation by ensuring that noise from different phase signals cancels out

Methodology Applied

Scientific EffectElectromagnetic radiation cancellation: Interference

Data Source

PatentUS11561644B2Display system and control method

Publication Date: 2023.01.24 PANASONIC AUTOMOTIVE SYST CO LTD

AI summary

In a display system, a display device includes multiple sensor electrodes divided into multiple groups. A second drive circuit supplies, to the multiple sensor electrodes, a touch drive signal having a phase different for each group. A touch detection circuit performs detection of a touch by an object on the display device, based on a detection signal received from the multiple sensor electrodes.