Lid Angle Estimation Using Sleep-Mode Orientation Sensing

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Solution Overview

Problem

Current lid angle detection solutions for foldable electronic devices are high cost and high power consumption, and fail to accurately determine the lid angle when the device is in an upright position or non-steady state, often requiring continuous operation even in sleep mode.

Innovation Solution

A device with low-powered first and second sensor units, each containing multiple sensors, performs lid angle detection in sleep mode, and a high-powered application processor updates the lid angle upon waking, using sensor measurements to calculate and remap the angle from 0 to 360 degrees.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If current lid angle detection solutions are used, then lid angle can be detected, but power consumption is high and cost is high

Engineering Contradiction:
Improvelid angle detection accuracyVSAvoidpower consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The system segments the processing tasks between low-powered sensor units (which continuously monitor orientation using accelerometers and gyroscopes) and the main application processor (which performs comprehensive lid angle calculation only when needed). This allows continuous detection capability while reducing overall power consumption by keeping the high-powered processor in sleep mode during inactive periods.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The sensor units continuously measure and calculate device orientation in advance, maintaining readiness to detect lid angle changes without requiring the main processor to be active. This preliminary action by the low-power sensor units enables the system to quickly resume accurate lid angle detection after sleep mode without high power consumption.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If lid angle detection is always running to handle upright position and non-steady state cases, then detection accuracy is maintained, but power consumption increases

Engineering Contradiction:
Improvedetection accuracy in upright and non-steady statesVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The system dynamically adjusts its operational state based on device conditions. The sensor units operate continuously at low power to monitor basic orientation, while the main application processor activates only when lid angle changes are detected or when the device transitions from sleep mode. This dynamic state management maintains detection reliability in upright and non-steady states while minimizing power consumption during stable periods.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system uses feedback from the sensor units' continuous orientation monitoring to trigger main processor activation only when necessary. When the sensor units detect significant orientation changes or lid angle variations, they signal the main processor to wake up and perform comprehensive lid angle calculation, ensuring accurate detection while avoiding unnecessary high-power operation during stable states.

Inventive Principle:
Principle #23Feedback

3Measurement precision

If hall sensors or magnetometers are used to solve upright position detection, then detection capability is improved, but cost and power consumption increase

Engineering Contradiction:
Improvelid angle detection in upright positionVSAvoidsensor cost and complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system makes the existing accelerometer and gyroscope sensors multi-functional by using them for both device orientation monitoring and lid angle detection. By processing sensor data differently based on device state (sleep vs. awake, upright vs. horizontal), the system achieves upright position detection capability without adding specialized sensors like hall sensors or magnetometers, thereby reducing cost and complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system changes the processing parameters and algorithms applied to sensor data based on device orientation and state. By analyzing accelerometer and gyroscope data with different computational approaches depending on whether the device is in upright or horizontal position, the system achieves accurate lid angle detection across all orientations using the same sensor hardware, avoiding the need for additional sensors.

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

Provides accurate, low-cost lid angle detection that functions in upright and non-steady states, reducing power consumption by allowing the high-powered processor to sleep during inactivity.

Implementation Method 1

the first and second sensor units measure acceleration and angular velocity, and calculate orientations of the respective lid components based on the acceleration and angular velocity measurements

Methodology Applied
Scientific EffectAcceleration measurement: Accelerometer

Implementation Method 2

the first and second sensor units measure acceleration and angular velocity, and calculate orientations of the respective lid components based on the acceleration and angular velocity measurements

Methodology Applied
Scientific EffectAngular velocity measurement: Gyroscope

Implementation Method 3

The application processor subsequently updates the initial lid angle using one or more of acceleration, magnetometer, or gyroscope measurements

Methodology Applied
Scientific EffectMagnetic field measurement: Magnetometer

Data Source

PatentEP4687003A1Lid angle detection
Publication Date: 2026.02.04 STMICROELECTRONICS INT NV
  • EP4687003A1 patent drawingFigure 1
  • EP4687003A1 patent drawingFigure 2~3
  • EP4687003A1 patent drawingFigure 4

AI summary

The present disclosure is directed to a device and method for lid angle detection that is accurate even if the device is activated in an upright position. While the device is in a sleep state, first and second sensor units measure acceleration and angular velocity, and calculate orientations of respective lid components based on the acceleration and angular velocity measurements. Upon the device exiting the sleep state, a processor determines a distance between the calculated orientations, remaps the distance to an estimated lid angle ranging from 0 to 360 degrees, sets the estimated lid angle as an initial lid angle, and updates the initial lid angle using, for example, two accelerometers; two accelerometers and two gyroscopes; two accelerometers and two magnetometers; or two accelerometers, two gyroscopes, and two magnetometers.