Rollable Flexible Display Rotation Sensing for Accurate Position Detection

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Solution Overview

Problem

Rollable electronic devices face challenges in accurately measuring the expanded or contracted length of their displays due to inaccuracies in motor rotation counting and interference from external magnetic fields, leading to errors in user interface and touch recognition.

Innovation Solution

A rollable electronic device with a processor, rotating members, and a rotation detection sensor that measures the rotation angle of the rotating members to determine the sliding movement distance of the display, using a hinge structure to support expansion and contraction while minimizing interference from external magnetic fields.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If motor rotation counting is used to measure display expansion, then device complexity is reduced, but measurement precision deteriorates due to accumulation errors

Engineering Contradiction:
Improvemeasurement system complexityVSAvoiddisplay position measurement accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent replaces the mechanical motor rotation counting system with a magnetic field-based detection system. A magnet is attached to the display assembly and a magnetic sensor detects its position, converting mechanical movement measurement into a magnetic field measurement system that provides higher precision without significant complexity increase.

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

Solution Approach 2:

The patent introduces a magnet as an intermediary element between the display assembly and the measurement system. The magnet serves as a marker that can be easily detected by magnetic sensors, enabling precise position measurement through magnetic field changes rather than direct mechanical counting.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If hall sensors are provided on the internal case to detect display position, then measurement precision improves, but device complexity increases due to magnetic field interference

Engineering Contradiction:
Improvedisplay position detection accuracyVSAvoidmagnetic field interference management
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

Instead of placing the sensor on the stationary internal case to detect a moving magnet, the patent inverts the approach by attaching the magnet to the stationary display assembly and using a magnetic sensor that moves with the display. This eliminates the need for complex interference shielding on the internal case while maintaining measurement precision.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The patent extracts the magnetic field detection function from the internal case structure and relocates it to the display assembly itself. By moving the magnetic sensor to the display assembly, the system eliminates magnetic field interference issues that would arise from having sensors in the internal case near other magnetic components.

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If a rotating member is added to support display expansion and contraction, then reliability of position measurement improves, but device complexity increases

Engineering Contradiction:
Improveposition measurement accuracyVSAvoidmechanical structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the rotating member with the existing display assembly structure. The magnet is attached directly to the display assembly which already has rotational movement capability for expansion and contraction, eliminating the need for a separate rotating member and reducing overall device complexity while maintaining measurement reliability.

Inventive Principle:
Principle #5Merging (Combining)

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 solution provides an optimal user experience by accurately measuring display position and reducing power consumption, preventing erroneous touch inputs, and maintaining a compact design without increasing device thickness or length.

Implementation Method 1

a magnet disposed on the flexible display and a rotation detection sensor configured to measure a rotation angle of the at least one rotating member on the rotating axis of the rotating member

Methodology Applied
Scientific EffectMagnetic field: Magnetic Field

Data Source

PatentEP4170459B1Rollable electronic device comprising flexible display
Publication Date: 2025.07.16 SAMSUNG ELECTRONICS CO LTD
  • EP4170459B1 patent drawingFigure 1
  • EP4170459B1 patent drawingFigure 2
  • EP4170459B1 patent drawingFigure 3

AI summary

Various embodiments of the present disclosure relate to an electronic device, for example, an electronic device comprising a rollable display. According to an embodiment, a rollable electronic device may be provided, the electronic device comprising: a housing including a first surface facing a first direction, a second surface facing a second direction opposite to the first direction, a first side member that is slidable in a third direction different from the first direction and the second direction, and a second side member facing a direction opposite to the first side member; a flexible display including a first area facing the first direction and a second area extending from the first area and facing the second direction opposite to the first direction; a plate which supports at least a portion of the flexible display and slidably moves so that at least a portion of the second area faces the first direction so as to substantially enable the expansion of the first area; at least one member enabling the sliding movement of the plate through a rotational movement; and a rotation detection sensor for detecting the degree of rotation while the at least one member rotates about a rotation axis. Various other embodiments can be applied.