Retractable Screen Sliding Rail for Flat, Low-Friction Motion

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Solution Overview

Problem

Existing electronic devices with retractable screens face challenges in smoothly and efficiently expanding and retracting flexible displays without causing visual distortions such as bulging or swelling, and there is a need for improved mechanisms to enhance stability and reduce friction during these operations.

Innovation Solution

The electronic device incorporates a sliding rail mechanism with a bracket, sliding rail assembly, and rotating shaft assembly, along with a driving mechanism that includes a driving motor and reduction gearbox to smoothly expand and retract the flexible display screen, utilizing elastic assemblies to maintain a flat appearance and minimize friction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of moving object

If a retractable screen structure is implemented to increase display area, then the display area can be dynamically adjusted, but the screen may experience visual distortions such as bulging or swelling during expansion and retraction

Engineering Contradiction:
Improvedisplay areaVSAvoidscreen flatness
Core Design Contradiction:
Area of moving objectVSShape

Solution Approach 1:

The screen expansion structure is divided into multiple segments including a sliding rail mechanism with separate sliding components. The screen itself is segmented into a fixed portion and a flexible portion that can independently move, allowing the flexible portion to expand and contract without causing the entire screen to bulge or swell.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A sliding rail mechanism serves as an intermediary between the fixed housing and the flexible screen portion. This intermediate structure guides the screen's movement along a predetermined path, ensuring smooth expansion and retraction while preventing direct contact between moving components that could cause distortion.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If a sliding rail mechanism is used to guide screen movement, then the screen can expand and retract smoothly, but friction between sliding components increases power loss

Engineering Contradiction:
Improvescreen expansion smoothnessVSAvoidpower loss due to friction
Core Design Contradiction:
Ease of operationVSLoss of energy

Solution Approach 1:

The traditional mechanical sliding contact system is replaced with a magnetic field-based driving mechanism. Magnetic components interact through the sliding rail without direct physical contact, eliminating friction between moving parts while still providing smooth guidance and actuation of the flexible screen portion.

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

3Extent of automation

If a driving mechanism with reduction gearbox is implemented to control screen movement, then precise control is achieved, but the device complexity increases

Engineering Contradiction:
Improvescreen control precisionVSAvoidmechanism complexity
Core Design Contradiction:
Extent of automationVSDevice complexity

Solution Approach 1:

The driving mechanism is integrated directly into the sliding rail structure, merging the guidance function and actuation function into a single unified component. The magnetic driving components are embedded within the sliding rail assembly, eliminating the need for separate reduction gearboxes and other complex transmission mechanisms.

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 ensures smooth expansion and retraction of the flexible display screen while preventing visual distortions, maintaining a flat appearance, and reducing power loss due to friction, thereby enhancing user experience and product reliability.

Implementation Method 1

an elastic assembly, including a first end and a second end, the first end being connected to the fixed base, and the second end being connected to the sliding member

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

the sliding member is slidably arranged on the fixed base along the first direction

Methodology Applied
Scientific EffectFriction reduction: Lubrication

Data Source

PatentEP4109212B1Electronic device with retractable screen
Publication Date: 2025.07.16 BEIJING XIAOMI MOBILE SOFTWARE CO LTD
  • EP4109212B1 patent drawingFigure 1
  • EP4109212B1 patent drawingFigure 2~3
  • EP4109212B1 patent drawingFigure 4~6

AI summary

An electronic device includes a first housing provided with a first sliding portion and a second housing slidably arranged on the first housing along a first direction, the first housing and the second housing being enclosed to form a receiving structure with an opening; a flexible display screen having a first end arranged at a side close to a bottom of the housing and a second end connected to the first housing to cover the opening; and a sliding rail mechanism including a bracket connected to the flexible display screen and provided with a second sliding portion matching the first sliding portion, the first sliding portion being one of a sliding rail and a sliding groove, the second sliding portion being the other. The sliding rail moves along the sliding groove to drive the flexible display screen to slide along the first direction relative to the first housing.