Rollable Display Key Input with Magnetic Position Sensing

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Solution Overview

Problem

There is a trade-off between increasing the display size and maintaining a compact form factor in portable electronic devices, and existing flexible display technologies do not effectively address this challenge.

Innovation Solution

A rollable electronic device with a key input device that includes a first housing and a second housing that can slide relative to each other, a display that moves based on this sliding motion, and a key input device with an elastic body and magnetic body detected by sensors to determine position, allowing the device to slide in or out based on sensor signals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If the display size is increased to provide better multimedia service experience, then the display area is improved, but the overall device size increases making it less portable

Engineering Contradiction:
Improvedisplay areaVSAvoiddevice size
Core Design Contradiction:
Area of stationary objectVSVolume of moving object

Solution Approach 1:

The patent implements a rollable display that can dynamically change its exposed area by rolling up or unrolling. The display transitions from a compact rolled state to an expanded unrolled state, allowing the device to provide a large display area when needed while maintaining a small portable form factor when not in use. This dynamic transformation resolves the contradiction between display size and device portability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The rolled-up display is nested within the device housing, with the display material wound around a roller mechanism. When not in use, the display is compacted and stored inside the device body similar to a nested structure, enabling the device to maintain a compact size while still providing access to a large display area when unrolled.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Area of stationary object

If a sliding mechanism is added to enable display expansion, then the display area is improved, but the device complexity increases

Engineering Contradiction:
Improvedisplay areaVSAvoidmechanism complexity
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The patent replaces traditional mechanical sliding or telescopic mechanisms with a magnetic field-based detection and control system. Magnetic sensors detect the position of magnetic bodies attached to the rolling components, and the system automatically controls the rolling/unrolling action based on sensor signals, eliminating the need for complex mechanical switches, buttons, or linkages.

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

Solution Approach 2:

The patent introduces magnetic fields as an intermediary between the user's manual input and the display rolling mechanism. Instead of direct mechanical contact or complex electrical connections, magnetic bodies and magnetic sensors act as intermediaries to detect position and trigger the appropriate rolling action, simplifying the overall system architecture.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Measurement precision

If magnetic sensors and magnetic bodies are used for position detection, then the positioning precision is improved, but the device complexity increases

Engineering Contradiction:
Improveposition detection precisionVSAvoidsensor system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The magnetic bodies are attached to moving components and automatically move with them, serving as self-contained position indicators. The magnetic sensors passively detect the position of these magnetic bodies without requiring active power consumption or complex processing, allowing the system to achieve precise position detection while maintaining simplicity.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The magnetic field detection system serves multiple functions: it detects the position of the rolled display, determines when the display is fully extended or retracted, and triggers the appropriate sliding or rolling action. This multi-functional approach reduces the need for separate sensors and control mechanisms for each function.

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

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 the expansion of the display area while maintaining a compact form factor by using a sliding mechanism with magnetic field detection for precise positioning, reducing malfunctions and enhancing user interaction.

Implementation Method 1

a sensor disposed on the frame and configured to detect a magnetic field of the magnetic body to determine a position of the key input device

Methodology Applied
Scientific EffectMagnetic field detection: Magnetic Field

Implementation Method 2

a key input device including an elastic body connected to the first cover member and a magnetic body connected to the elastic body

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4336812B1Rollable electronic device comprising key input device
Publication Date: 2026.02.11 SAMSUNG ELECTRONICS CO LTD
  • EP4336812B1 patent drawingFigure 1
  • EP4336812B1 patent drawingFigure 2
  • EP4336812B1 patent drawingFigure 3

AI summary

An electronic device may be provided. The electronic device includes a first housing including a first cover member and a frame located inside the first cover member, a second housing at least partially accommodated inside the cover member and configured to move relative to the first housing, a display configured to be moved based on the movement of the second housing, a key input device including an elastic body connected to the first cover member and a magnetic body connected to the elastic body, and a sensor disposed on the frame and configured to detect a magnetic field of the magnetic body.