TMOS User Presence Detection With Motion and Baseline Analysis

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Solution Overview

Problem

Current human presence/absence detection technologies in personal computers face reliability issues with charge variation sensors, high costs and energy consumption with ToF sensors, and detection inaccuracies with TMOS sensors, particularly in detecting user presence within the field of view and handling environmental drifts.

Innovation Solution

A detection system using a TMOS sensor coupled with a control unit implementing motion and baseline analysis to generate detection confidence signals, ensuring accurate and reliable detection of user presence or absence within a defined field of view, enabling precise triggering of Wake on Approach and Lock on Leave functionalities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If ToF sensors are used for presence detection, then detection accuracy is improved, but manufacturing cost and energy consumption increase significantly

Engineering Contradiction:
Improvedetection accuracyVSAvoidenergy consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent changes the detection parameter from active time-of-flight measurement to passive infrared radiation detection. The TMOS sensor detects thermal radiation emitted by the human body in the infrared spectrum, eliminating the need for active illumination and complex time measurement circuits, thereby reducing energy consumption while maintaining detection accuracy.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces the mechanical/electronic time-of-flight measurement system with a thermal radiation detection system. Instead of measuring the time for light to travel to and from the object, the system directly detects the infrared radiation emitted by the object's thermal energy, simplifying the detection mechanism and reducing power requirements.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If ToF sensors are used for presence detection, then detection accuracy is improved, but manufacturing cost increases

Engineering Contradiction:
Improvedetection accuracyVSAvoidmanufacturing cost
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent changes the detection parameter from active time-of-flight measurement to passive infrared radiation detection. The TMOS sensor detects thermal radiation emitted by the human body in the infrared spectrum, eliminating the need for active illumination and complex time measurement circuits, thereby reducing energy consumption while maintaining detection accuracy.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces the mechanical/electronic time-of-flight measurement system with a thermal radiation detection system. Instead of measuring the time for light to travel to and from the object, the system directly detects the infrared radiation emitted by the object's thermal energy, simplifying the detection mechanism and reducing power requirements.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Ease of manufacture

If charge variation sensors are used for presence detection, then manufacturing cost is reduced, but reliability deteriorates due to inability to detect stationary users

Engineering Contradiction:
Improvemanufacturing costVSAvoiddetection reliability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent replaces the charge variation detection mechanism with thermal radiation detection. The TMOS sensor detects infrared radiation emitted by the human body's thermal energy, which is independent of motion. This allows reliable detection of both moving and stationary users, significantly improving detection reliability while maintaining low cost.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the detection parameter from charge variation (motion-dependent) to thermal radiation detection (motion-independent). The TMOS sensor detects the infrared radiation emitted by the human body's thermal energy, which is present regardless of whether the user is moving or stationary, thereby improving reliability.

Inventive Principle:
Principle #35Parameter changes

4Use of energy by moving object

If TMOS sensors are used for presence detection, then energy consumption and manufacturing cost are reduced, but detection accuracy deteriorates due to environmental temperature drifts

Engineering Contradiction:
Improveenergy consumptionVSAvoiddetection accuracy
Core Design Contradiction:
Use of energy by moving objectVSMeasurement precision

Solution Approach 1:

The patent implements a feedback mechanism where the system continuously monitors the baseline infrared radiation level and dynamically adjusts the detection threshold. The processor compares current radiation levels against learned environmental baselines and adapts the detection algorithm to compensate for temperature drifts, maintaining accuracy while using low-power TMOS sensors.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent performs preliminary environmental scanning and baseline establishment before actual presence detection. The system characterizes the environmental infrared radiation profile during an initialization period, storing this baseline information for later comparison. This preliminary action enables the system to distinguish between environmental temperature changes and actual human presence, maintaining detection accuracy.

Inventive Principle:
Principle #10Preliminary action

5Ease of manufacture

If motion analysis through charge variation sensors is used, then manufacturing cost is reduced, but detection reliability deteriorates

Engineering Contradiction:
Improvemanufacturing costVSAvoiddetection reliability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent replaces the charge variation detection mechanism with thermal radiation detection. The TMOS sensor detects infrared radiation emitted by the human body's thermal energy, which is independent of motion. This allows reliable detection of both moving and stationary users, significantly improving detection reliability while maintaining low cost.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the detection parameter from charge variation (motion-dependent) to thermal radiation detection (motion-independent). The TMOS sensor detects the infrared radiation emitted by the human body's thermal energy, which is present regardless of whether the user is moving or stationary, thereby improving reliability.

Inventive Principle:
Principle #35Parameter changes

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

The system provides accurate and reliable detection of user presence/absence with low energy consumption, addressing the limitations of existing technologies by ensuring timely activation/deactivation of PC functionalities.

Implementation Method 1

detection of the presence of the user on the basis of infrared radiation sensors (e.g. 'Thermal MOS', TMOS, sensors)

Methodology Applied
Scientific EffectInfrared radiation detection: Infrared Radiation

Data Source

PatentEP4597054A1Detection system for detecting the presence or absence of a user
Publication Date: 2025.08.06 STMICROELECTRONICS INT NV
  • EP4597054A1 patent drawingFigure 1
  • EP4597054A1 patent drawingFigure 2
  • EP4597054A1 patent drawingFigure 3

AI summary

Detection system (20) for detecting the presence or absence of a user (11), comprising: an IR radiation sensor (22) for detecting the IR radiation emitted by the user (11); and a control unit (24; 28) for receiving from the IR radiation sensor (22) an IR radiation signal (Tobject). The control unit (24; 28) is configured to, on the basis of the IR radiation signal (Tobject): determine the presence/absence of the user (11) through motion analysis; verify whether a presence check or absence check condition has been detected; if so, verify whether the presence or absence of the user is confirmed (11); if the presence or absence of the user (11) is confirmed, continue to determine the presence or absence of the user (11) through baseline analysis performed as a function of the information of presence or absence of the user (11) previously confirmed.