Dynamic Surface Temperature Control for Wearable Device Comfort

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Solution Overview

Problem

Electronic devices, such as wearable computing devices and laptops, generate excess heat during operation, which can cause discomfort if not mitigated, leading to premature shutdowns when using static temperature limits, despite users being able to tolerate higher temperatures for longer periods.

Innovation Solution

Implementing a dynamic temperature limit function that adjusts based on an energy accumulator value, incrementing or decrementing it according to surface temperature and user contact, allowing for a variable temperature limit that reflects cumulative energy received by the user.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a static temperature limit is used to prevent overheating, then user safety is ensured, but device operation time is reduced due to premature shutdowns

Engineering Contradiction:
Improveuser safetyVSAvoiddevice operation time
Core Design Contradiction:
ReliabilityVSDuration of action of moving object

Solution Approach 1:

The patent applies dynamics by transitioning from a static temperature limit to a dynamic temperature limit that changes over time based on cumulative energy exposure. The system continuously monitors the energy accumulator value and adjusts the temperature limit accordingly, allowing the device to operate safely for extended periods while preventing overheating damage.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements parameter changes by modifying the temperature limit parameter based on the energy accumulator value. As the energy accumulator increases with cumulative energy exposure, the temperature limit is adjusted dynamically, enabling the system to adapt its thermal management strategy to the current thermal history of the device.

Inventive Principle:
Principle #35Parameter changes

2Duration of action of moving object

If a dynamic temperature limit function is implemented, then device operation time is extended, but system complexity increases

Engineering Contradiction:
Improvedevice operation timeVSAvoidsystem complexity
Core Design Contradiction:
Duration of action of moving objectVSDevice complexity

Solution Approach 1:

The patent applies feedback by continuously monitoring the surface temperature and energy accumulator value, then using this information to adjust the temperature limit dynamically. The system measures the current state, compares it against the dynamic limit, and modifies operation accordingly, creating a closed-loop thermal management system that extends device operation time.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent implements preliminary action by pre-calculating and storing multiple temperature limit values corresponding to different energy accumulator ranges. This allows the system to quickly switch between predefined temperature limits based on the current energy accumulation state, reducing computational complexity while still achieving dynamic thermal management.

Inventive Principle:
Principle #10Preliminary 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

Enables users to comfortably operate devices for longer periods by dynamically adjusting temperature limits, preventing unnecessary shutdowns and enhancing user experience.

Implementation Method 1

a cooling system in thermal communication with the surface and configured to cool the surface to below the temperature limit

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Data Source

PatentEP3999934B1Regulating device surface temperature
Publication Date: 2026.02.18 MICROSOFT TECHNOLOGY LICENSING LLC
  • EP3999934B1 patent drawingFigure 1~2
  • EP3999934B1 patent drawingFigure 3
  • EP3999934B1 patent drawingFigure 4

AI summary

Examples are disclosed that relate to methods, computing devices, and head-mounted display (HMD) devices for regulating a surface temperature of a device. In one example, a method comprises determining the surface temperature of a surface of the device, determining an energy accumulator value indicating cumulative energy received by a user via the surface of the device, and using a dynamic temperature limit function to calculate a temperature limit as a function of the energy accumulator value. The method also comprises comparing the surface temperature to the temperature limit. When the surface temperature has not reached the temperature limit, the method comprises incrementing the energy accumulator value. When the surface temperature has reached the temperature limit, the method comprises initiating a thermal mitigation action to cool the surface.