Input Device Distance Measurement Using Voltage-Normalized Signals

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing computing devices face inaccuracies in determining the distance of an input device from a surface due to variations in voltage generated by different input devices, leading to unreliable distance calculations, especially when using machine learning models trained on a single 'golden' pen.

Innovation Solution

Determine an effective voltage for the input device using a voltage data model, adjust input device signals based on this voltage, and apply these adjusted signals to a distance model to calculate the device's distance from the surface, utilizing techniques like linear regression and neural networks to compensate for voltage variations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a distance model is trained on a single 'golden' pen, then the training process is simplified, but the distance determination accuracy deteriorates when used with other input devices having different voltage characteristics

Engineering Contradiction:
Improvetraining process simplicityVSAvoiddistance determination accuracy
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent transforms the raw input device signals by applying a voltage normalization factor derived from the effective voltage of the input device. This parameter transformation adjusts the signal characteristics to match the training conditions, allowing the distance model trained on a 'golden' pen to accurately process signals from other input devices with different voltage profiles.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces an effective voltage calculation as an intermediary step between signal reception and distance determination. This intermediary process computes a normalization factor that mediates between the actual input device signals and the distance model expectations, enabling accurate distance measurement across different device variations.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If voltage variations between different input devices are not compensated, then the system complexity is reduced, but the reliability of distance calculations deteriorates

Engineering Contradiction:
Improvesystem complexityVSAvoiddistance calculation reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent performs preliminary voltage characterization by calculating the effective voltage of each input device before using it for distance measurements. This preliminary action establishes a normalization factor that compensates for voltage variations, ensuring reliable distance calculations without requiring separate models for each device.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements a dynamic adaptation mechanism where the effective voltage and normalization factor are determined for each input device individually. This dynamic approach allows the system to adapt to different voltage characteristics of various input devices rather than using a fixed compensation scheme.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4158454B1Determining a distance to an input device
Publication Date: 2025.08.20 MICROSOFT TECHNOLOGY LICENSING LLC
  • EP4158454B1 patent drawingFigure 1
  • EP4158454B1 patent drawingFigure 2~3
  • EP4158454B1 patent drawingFigure 4

AI summary

Examples are disclosed that relate to methods and computing devices for determining a distance of an input device from a surface of a computing device. In one example, a method comprises receiving a plurality of input device signals via the input device. A portion of the input device signals are used to determine an effective voltage of the input device. Adjusted input device signals are generated by adjusting another portion of input device signals using the effective voltage of the input device. The method further comprises providing the adjusted input device signals as an input to a distance model, and receiving and outputting the distance of the input device from the surface of the computing device.