Reconfigurable Stylus Sensing Electrodes for Thin Low-Noise Touch Panels

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Solution Overview

Problem

Inductive touch or proximity sensors require additional sensing and shielding layers, increase device thickness, and introduce noise, making them less desirable compared to capacitive touch sensing.

Innovation Solution

The use of electrodes configured for either capacitive touch sensing or inductive sensing, where sense pixels with two or four conductive elements form conductive pathways for single-ended or differential capacitive touch sensing, or loops for inductive sensing, allowing for electrodes to be optimized for both sensing modes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If inductive sensing layers are added to detect stylus, then stylus detection capability is improved, but device thickness increases

Engineering Contradiction:

Improvestylus detection capabilityVSAvoiddevice thickness

Core Design Contradiction:

ReliabilityVSLength of stationary object

Solution Approach 1:

The patent makes the existing capacitive electrode structure perform both capacitive touch sensing and inductive stylus sensing functions. The same electrodes that detect finger touches are configured to detect stylus proximity through inductive coupling, eliminating the need for separate inductive sensing layers and thus avoiding increased device thickness.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent combines capacitive and inductive sensing capabilities into a single integrated electrode system. By configuring the electrodes to operate in both sensing modes depending on the detected object (finger vs. stylus), the design merges two previously separate sensing systems into one unified structure.

Inventive Principle:

Principle #5Merging (Combining)

2Reliability

If inductive sensing layers are added to detect stylus, then stylus detection capability is improved, but noise is introduced

Engineering Contradiction:

Improvestylus detection capabilityVSAvoidnoise

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The existing capacitive electrodes are made multi-functional to perform both capacitive and inductive sensing. This eliminates the need for separate inductive sensing circuits that would generate additional noise, as the same hardware infrastructure is used for both sensing modes.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

By merging capacitive and inductive sensing into a single electrode system, the patent avoids introducing separate noise-generating sensing circuits. The unified approach allows the system to leverage the existing low-noise capacitive infrastructure while adding inductive capability through configuration rather than additional hardware.

Inventive Principle:

Principle #5Merging (Combining)

3Reliability

If additional sensing layers are added for inductive sensing, then stylus detection capability is improved, but device complexity increases

Engineering Contradiction:

Improvestylus detection capabilityVSAvoidsensing structure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent makes the existing electrode structure universal, capable of performing both capacitive touch sensing and inductive stylus sensing. This eliminates the need for additional sensing layers and reduces device complexity by utilizing the same hardware infrastructure for multiple sensing functions.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges capacitive and inductive sensing capabilities into a single integrated system. By configuring existing electrodes to perform dual functions rather than adding separate sensing layers, the design reduces structural complexity while maintaining both sensing capabilities.

Inventive Principle:

Principle #5Merging (Combining)

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 configuration enables efficient touch and proximity detection using a single electrode system that minimizes thickness and noise, providing versatile and effective touch screen functionality.

Implementation Method 1

capacitive touch sensing

Methodology Applied

Scientific EffectCapacitive coupling: Capacitance

Implementation Method 2

inductive sensing

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentUS12474801B1Inductive stylus sensing

Publication Date: 2025.11.18 APPLE INC

AI summary

Electrodes configurable for capacitive touch sensing or inductive sensing are disclosed. The electrodes are formed from a plurality of tiled (connected) sense pixels, each sense pixel including two or four conductive elements. The conductive elements within the plurality of sense pixels of an electrode are connected to form conductive pathways within the electrode. These conductive pathways enable each electrode to be configured as a touch electrode for single-ended or differential capacitive touch sensing, or into one or two loops for inductive sensing. In pixels with four conductive elements, two conductive elements are formed with a comb shape for maximizing current conduction during inductive sensing and maximizing capacitive coupling during touch sensing, and two conductive elements are formed as bypasses. In electrodes formed from sense pixels with four conductive elements, each conductive pathway within the electrode is formed as an alternating series of comb-shaped conductive elements and bypasses.