Stylus Tip Status Verification via Electrostatic Coupling

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Solution Overview

Problem

Digitizer systems often experience errors where the stylus incorrectly identifies its tip status as 'touch' when no force is applied, leading to 'inking in hover' issues, due to mechanical problems requiring external calibration.

Innovation Solution

The stylus and digitizer sensor collaborate to verify the tip status, with the sensor sending notifications to correct errors, allowing the stylus to recalibrate its pressure sensor and the system to adjust accordingly, using wireless communication channels like electrostatic or Bluetooth.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the stylus uses a mechanical pressure sensor to detect tip contact, then pressure sensitivity is improved, but mechanical failures cause false 'touch' readings when no force is applied

Engineering Contradiction:
Improvepressure detection accuracyVSAvoidtip status detection reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent introduces an electrostatic field-based detection mechanism as an intermediary to verify the mechanical pressure sensor's readings. The digitizer sensor detects electrostatic coupling between the stylus tip and the sensor surface, providing an independent verification channel that mediates the reliability issue of the mechanical sensor without compromising pressure sensitivity.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system implements a feedback mechanism where the digitizer sensor continuously monitors electrostatic coupling and compares it with mechanical sensor readings. When discrepancies are detected (e.g., mechanical sensor indicates touch but electrostatic coupling is absent), the system receives feedback to correct the false reading, ensuring reliable tip status detection.

Inventive Principle:
Principle #23Feedback

2Manufacturing precision

If external calibration equipment is used to correct mechanical sensor errors, then manufacturing precision is improved, but device complexity and calibration requirements increase

Engineering Contradiction:
Improvesensor calibration accuracyVSAvoidcalibration system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent enables the stylus-digitizer system to perform self-calibration using the electrostatic field detection mechanism. The system automatically detects and corrects calibration drift by comparing electrostatic coupling readings with mechanical sensor readings, eliminating the need for external calibration equipment and reducing device complexity while maintaining manufacturing precision.

Inventive Principle:
Principle #25Self-service

3Measurement precision

If the system continuously monitors tip status to prevent inking in hover, then writing accuracy is improved, but energy consumption increases

Engineering Contradiction:
Improvetip contact detection accuracyVSAvoidstylus energy consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The system implements periodic sampling of electrostatic coupling rather than continuous monitoring. The digitizer sensor checks for stylus presence and tip status at regular intervals during hover and writing operations, maintaining writing accuracy while significantly reducing energy consumption compared to continuous monitoring.

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 collaboration effectively resolves the 'inking in hover' problem by ensuring accurate tip status detection and recalibration, enhancing the reliability of stylus input in digitizer systems.

Implementation Method 1

a pressure sensor for detecting applied pressure on the tip

Methodology Applied
Scientific EffectPressure sensing:

Implementation Method 2

Tracking is based on detecting a signal emitted by a tip of the stylus and picked up by the digitizer sensor due to electrostatic coupling established between the tip and a portion of the matrix of electrode junctions

Methodology Applied
Scientific EffectElectrostatic coupling: Electrostatics

Data Source

PatentEP3427133B1Pen in field force sensing calibration
Publication Date: 2023.12.13 MICROSOFT TECHNOLOGY LICENSING LLC
  • EP3427133B1 patent drawingFigure 1
  • EP3427133B1 patent drawingFigure 2
  • EP3427133B1 patent drawingFigure 3A

AI summary

A method for identifying an error in a tip status indication from a stylus includes detecting input from a stylus with a digitizer sensor via an electrostatic (ES) wireless communication channel established between said stylus and said digitizer sensor. An indication of a tip status is received from the stylus, indicating whether the tip status is in hover or touch. The tip status is verified based on input detected with the digitizer sensor. When an error is identified in the tip status indication, a notification of the error is sent.