Stylus Pen Position Correction via Capacitive Reference

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Solution Overview

Problem

Existing stylus pens using electromagnetic induction schemes suffer from inaccurate touch recognition when slanted, leading to incorrect position detection on touch screens, affecting the user's experience and accuracy of cursive character input and image memo functions.

Innovation Solution

The integration of an electrostatic rubber on the rim of the stylus pen's tip, combined with a capacitive touch panel, allows for simultaneous detection of the stylus's position through both electromagnetic induction and capacitance changes, enabling correction of the recognized position and enhancing touch recognition accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If electromagnetic induction scheme is used for stylus pen, then touch recognition is enabled, but position detection accuracy deteriorates when stylus is slanted

Engineering Contradiction:

Improvetouch recognitionVSAvoidposition detection accuracy

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The patent combines electromagnetic induction detection (for stylus identification) and capacitive touch detection (for position sensing) into a unified input system. The stylus pen contains both a resonance circuit for electromagnetic induction and a conductive tip for capacitive coupling, allowing the system to receive both types of signals simultaneously and determine touch position more accurately even when the stylus is slanted.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The conductive tip of the stylus acts as an intermediary that enables capacitive coupling with the touch panel. This intermediary element allows the system to detect position through capacitance changes in addition to electromagnetic induction, providing a reference point that corrects for slant-induced positioning errors.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If resonance circuit is spaced apart from tip, then electromagnetic induction is improved, but magnetic field distribution becomes uneven when slanted

Engineering Contradiction:

Improveelectromagnetic inductionVSAvoidmagnetic field distribution

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent applies different functional qualities to different parts of the stylus: the resonance circuit is positioned away from the tip to optimize electromagnetic induction, while the conductive tip is positioned at the end to provide localized capacitive coupling. This local differentiation allows each component to perform its function optimally without interfering with the other, maintaining stable magnetic field distribution even when slanted.

Inventive Principle:

Principle #3Local quality

3Device complexity

If single detection method is used, then device complexity is reduced, but touch recognition accuracy deteriorates

Engineering Contradiction:

Improvedetection systemVSAvoidtouch recognition accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The stylus pen is designed with multi-functionality, incorporating both electromagnetic induction capabilities (resonance circuit) and capacitive touch capabilities (conductive tip). The touch panel system similarly handles both electromagnetic induction signals and capacitive touch signals. This multi-functional design enables accurate touch recognition across various stylus orientations without significantly increasing overall system complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 solution improves the accuracy of touch recognition by aligning the recognized position with the actual tip position, providing better user feedback and enhancing the usability of cursive character input and image memo functions on touch screens.

Implementation Method 1

If the stylus pen 20 approaches the electromagnetic field of the digitizer pad 35, an electromagnetic induction phenomenon is generated and the resonance circuit 22 of the stylus pen 20 generates current.

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

The resonance circuit 22 of the stylus pen 20 forms a magnetic field 23 using the generated current.

Methodology Applied

Scientific EffectMagnetic field generation: Electromagnet

Implementation Method 3

detecting a second position using a capacitance change from a touch panel

Methodology Applied

Scientific EffectCapacitance change: Capacitance

Data Source

PatentUS9569041B2Stylus pen, input processing method using the same, and electronic device therefor

Publication Date: 2017.02.14 SAMSUNG ELECTRONICS CO LTD

AI summary

An electronic device includes a digitizer pad, a touch panel which is disposed above the digitizer pad, a digitizer pad controller configured to detect a first position using electromagnetic induction from the digitizer pad, a touch panel controller configured to detect a second position about a capacitance change from the touch panel, and a host device configured to correct the first position with reference to the second position and specifying the corrected first position as a touch position. A method includes detecting a first position using electromagnetic induction from a digitizer pad, detecting a second position using a capacitance change from a touch panel, correcting the first position with reference to the second position, and specifying the corrected first position as a touch position.