Foldable Lid Angle Detection Using Sleep-State Sensor Fusion

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current lid angle detection solutions for foldable electronic devices are costly and consume high power, and they fail to accurately determine the lid angle when the device is in an upright position or a non-steady state.

Innovation Solution

A device with low-powered first and second sensor units, each equipped with multiple sensors, performs lid angle detection while the device is in a sleep state, and a high-powered application processor estimates the lid angle using the calculated orientations upon awakening.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

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

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

Solution Approach 1:

The patent applies preliminary action by pre-calculating and storing orientation data using low-powered sensor units during sleep mode. The sensor units continuously measure acceleration and angular velocity, and the system pre-determines lid orientations before the high-powered application processor needs to wake up. This allows the main processor to quickly estimate the lid angle upon awakening without needing to continuously run high-power detection algorithms.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent segments the lid angle detection system into two distinct components: low-powered sensor units that continuously monitor orientation using accelerometers and gyroscopes, and a high-powered application processor that performs comprehensive angle calculation only when needed. This segmentation allows continuous monitoring at low power consumption while maintaining accurate detection capability when the full processor power is available.

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If current lid angle detection solutions are used, then lid angle can be detected, but the device incurs high cost

Engineering Contradiction:
Improvelid angle detection accuracyVSAvoidmanufacturing cost
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent applies universality by designing sensor units that perform multiple functions: they track device orientation, monitor lid angle, and provide data for both sleep-mode and awake-mode operations. The same accelerometer and gyroscope components serve dual purposes of maintaining device orientation awareness and enabling lid angle detection, eliminating the need for separate dedicated lid angle sensors and reducing overall system cost.

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

Solution Approach 2:

The patent uses copying by leveraging existing orientation data from accelerometers and gyroscopes to derive lid angle information. Instead of using expensive dedicated lid angle sensors, the system copies and processes data from already-present motion sensors, calculating the relative orientation between lid components through software algorithms that analyze acceleration and angular velocity patterns.

Inventive Principle:
Principle #26Copying

3Reliability

If lid angle detection is always running to manage upright and non-steady states, then accurate detection is maintained, but power consumption becomes excessively high

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

Solution Approach 1:

The patent implements periodic action by having the high-powered application processor wake up at regular intervals or upon specific events to perform comprehensive lid angle calculations, while low-powered sensor units continuously collect orientation data between these periods. The system periodically resets orientation processing logic when the device is fully open and steady, maintaining reliability without requiring continuous high-power operation.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent applies dynamics by making the processing logic adaptive and state-dependent. The system dynamically adjusts its behavior based on device state: low-powered continuous monitoring during sleep mode, periodic comprehensive calculations when awake, and selective resetting of orientation logic based on detected device states (fully open, closed, or intermediate). This dynamic approach maintains reliability across varying conditions while optimizing power consumption.

Inventive Principle:
Principle #15Dynamics

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 keeping the sensor units active during sleep mode.

Implementation Method 1

a first sensor unit including a first accelerometer, a first gyroscope, and a first processor, the first processor configured to determine a first orientation of the first housing based on measurements by the first accelerometer and the first gyroscope

Methodology Applied
Scientific EffectAccelerometer: Accelerometer

Implementation Method 2

a first sensor unit including a first accelerometer, a first gyroscope, and a first processor, the first processor configured to determine a first orientation of the first housing based on measurements by the first accelerometer and the first gyroscope

Methodology Applied
Scientific EffectGyroscope: Gyroscope

Data Source

PatentEP4283435B1Device and method for lid angle detection
Publication Date: 2026.02.18 STMICROELECTRONICS SRL
  • EP4283435B1 patent drawingFigure 1
  • EP4283435B1 patent drawingFigure 2~3
  • EP4283435B1 patent drawing

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 estimates the lid angle using the calculated orientations, 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.