Passive Resonant Stylus Electrode Mesh for Thin Touch Sensing

Solution Overview

Problem

Existing touch sensors, particularly those using electro-magnetic resonance (EMR) type passive stylus pens, face challenges with miniaturization and flexibility due to thick digitizers and digitizer coils, which hinder the thinning and miniaturization of electronic devices, and suffer from poor touch recognition.

Innovation Solution

A touch device with a resonance circuit and electrodes formed as a metal mesh, where currents in traces and electrodes are induced in opposite directions, allowing for thinner and smaller form factor, improved signal-noise-ratio (SNR), and enhanced reception sensitivity, along with a magnetic field shielding layer to manage electromagnetic interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If EMR type passive stylus pens with digitizer coils are used, then touch recognition is improved, but device thickness and size increase

Engineering Contradiction:

Improvetouch recognitionVSAvoiddevice thickness

Core Design Contradiction:

Measurement precisionVSLength of stationary object

Solution Approach 1:

The patent combines the touch sensor electrodes and the resonance circuit into a single integrated structure. The electrodes serve dual purposes: as touch sensing elements and as the resonance circuit components. This merging eliminates the need for separate digitizer coils, thereby reducing device thickness while maintaining EMR-based passive stylus recognition capability.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The electrodes are designed to perform multiple functions: they act as both the touch sensing electrodes for detecting finger touches and as the resonance circuit elements for EMR-based passive stylus recognition. This multi-functionality allows the system to maintain both touch recognition capabilities and stylus functionality without requiring separate dedicated components, thus reducing overall device thickness.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Measurement precision

If EMR type passive stylus pens with digitizer coils are used, then touch recognition is improved, but device miniaturization is hindered

Engineering Contradiction:

Improvetouch recognitionVSAvoiddevice size

Core Design Contradiction:

Measurement precisionVSVolume of moving object

Solution Approach 1:

The patent merges the touch sensor electrodes and the resonance circuit into a single integrated structure. The electrodes serve dual purposes: as touch sensing elements and as the resonance circuit components. This merging eliminates the need for separate digitizer coils, thereby reducing device thickness while maintaining EMR-based passive stylus recognition capability.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The electrodes are designed to perform multiple functions: they act as both the touch sensing electrodes for detecting finger touches and as the resonance circuit elements for EMR-based passive stylus recognition. This multi-functionality allows the system to maintain both touch recognition capabilities and stylus functionality without requiring separate dedicated components, thus reducing overall device thickness.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Ease of manufacture

If passive stylus pens without batteries are used, then manufacturing cost is reduced, but touch recognition performance deteriorates

Engineering Contradiction:

Improvemanufacturing costVSAvoidtouch recognition

Core Design Contradiction:

Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent replaces the mechanical/electronic battery-based active stylus system with a passive electromagnetic resonance-based system. By using the integrated electrodes as both touch sensors and resonance circuits, the system enables passive stylus recognition without batteries, reducing manufacturing costs while maintaining acceptable touch recognition performance through the EMR mechanism.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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

The solution enables reduced manufacturing costs, thinner device form factor, improved touch position calculation accuracy, and enhanced palm rejection capabilities.

Implementation Method 1

the traces may include traces in which directions of currents induced in the traces by the resonance circuit are opposite to each other

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

A touch device with a resonance circuit and electrodes formed as a metal mesh, where currents in traces and electrodes are induced in opposite directions, allowing for thinner and smaller form factor, improved signal-noise-ratio (SNR), and enhanced reception sensitivity, along with a magnetic field shielding layer to manage electromagnetic interference.

Methodology Applied

Scientific EffectMagnetic field shielding: Magnetic Field

Data Source

PatentUS12602121B2Touch device for passive resonant stylus, driving method for the same and touch system

Publication Date: 2026.04.14 HIDEEP INC

AI summary

An embodiment of the present invention provides a touch device for sensing a position of a stylus including a resonance circuit, including: a plurality of electrode; and a touch controller configured to receive a sensing signal from the electrodes to determine a position of the stylus, wherein the electrodes includes electrodes in which directions of currents induced in the electrodes by the resonance circuit are opposite to each other.