Rollable Display Rack Gear Structure for Compact Expansion

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Solution Overview

Problem

There is a trade-off between display size and compactness in portable electronic devices, as they need to accommodate increasing multimedia functions while maintaining portability.

Innovation Solution

A rollable electronic device design incorporating a rack gear mechanism, comprising a first housing that slides relative to a second housing, driven by a motor structure, with a pinion gear and rack gear system, utilizing materials with different properties in specific parts for enhanced functionality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If the display size of electronic devices is increased to accommodate multimedia services, then the display area is improved, but the compactness and portability deteriorate

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

Solution Approach 1:

The display system is segmented into a fixed display portion and a movable rollable display portion. The rollable display can be extended when multimedia services are needed and retracted when portability is required, effectively separating the display functionality from the device's compact form factor.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The display size is made dynamic through the rack and pinion gear mechanism that allows the display to extend and retract on demand. This transforms the display from a static component to a dynamic one that can adapt its size based on usage requirements, resolving the contradiction between large display area and compact device volume.

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If a rack gear mechanism is used to enable display expansion, then the adaptability is improved, but the device complexity increases

Engineering Contradiction:
Improvedisplay size adaptabilityVSAvoidmechanical structure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The rack gear mechanism serves multiple functions: it drives the rollable display extension/retraction, provides structural support for the movable portion, and acts as a guide for linear motion. This multi-functionality reduces the need for additional separate components, thereby limiting the increase in device complexity despite the improved adaptability.

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

Solution Approach 2:

The rack and pinion gear system acts as an intermediary mechanism that converts rotational motion from a motor into linear motion for display extension. This intermediary mechanism provides a reliable and compact solution for achieving display size adaptability without requiring complex direct-drive or pneumatic-hydraulic systems.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 flexible display expansion, balancing display size and compactness, allowing users to utilize multimedia services effectively without compromising portability.

Implementation Method 1

a pinion gear configured to rotate based on the driving power generated by the motor structure, and a rack gear disposed in the housing and configured to mesh with the pinion gear

Methodology Applied
Scientific EffectGear mechanism: Gear

Data Source

PatentEP4361763B1Rollable electronic device comprising rack gear
Publication Date: 2026.04.01 SAMSUNG ELECTRONICS CO LTD
  • EP4361763B1 patent drawingFigure 1
  • EP4361763B1 patent drawingFigure 2
  • EP4361763B1 patent drawingFigure 3

AI summary

Provided is an electronic device. The electronic device comprises: a housing including a first housing and a second housing which accommodates at least part of the first housing and moves relative to the first housing; a display which is unfolded on the basis of the sliding movement of the first housing; a motor structure which is arranged in the housing and generates a driving force for sliding movement of the first housing; a pinion gear which is rotated on the basis of the driving force generated by the motor structure; and a rack gear which is arranged in the housing, and is to be engaged with the pinion gear. The rack gear comprises: a first portion including at least one recess, the first portion being formed of a first material; and a second portion including a lower region disposed under the first portion and at least partially accommodated in the at least one recess.