Slider-Linked Hinge Assembly for Synchronous Foldable Screen Rotation

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Solution Overview

Problem

Foldable mobile devices face issues with non-standard gears causing high processing costs, abnormal noise, and tooth breakage due to gear meshing, and asynchronous screen rotation during folding and unfolding.

Innovation Solution

A hinge assembly that replaces gears with a base, swing arms, and sliders to achieve synchronous rotation, using elastic members and damping systems for smooth operation and reduced noise.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If non-standard gears are used to implement synchronous rotation, then the screen rotation synchronization is achieved, but the processing costs increase and the device complexity increases

Engineering Contradiction:
Improvescreen rotation synchronizationVSAvoidprocessing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent uses a standard gear (first gear) to replicate the rotational motion and transmits it through a transmission mechanism (bevel gears) to the second gear, creating a copied motion path that achieves synchronization without requiring multiple non-standard gears. This reduces manufacturing complexity while maintaining the synchronization function.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The first gear serves multiple functions: it directly engages with the first rotating component for motion transmission, and also drives the second gear through the transmission mechanism to synchronize the second rotating component. This multi-functionality eliminates the need for separate non-standard gears for each component.

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

2Reliability

If non-standard gears are used to implement synchronous rotation, then the screen rotation synchronization is achieved, but the device complexity increases

Engineering Contradiction:
Improvescreen rotation synchronizationVSAvoidgear structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Instead of designing two unique non-standard gears, the patent uses a standard first gear that copies its rotational motion to a second gear through a transmission mechanism. This standardization reduces structural complexity while achieving the same synchronization effect.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The transmission mechanism consisting of bevel gears acts as an intermediary between the first gear and the second rotating component. This mediator translates and transmits motion in a standardized way, reducing the complexity that would arise from direct non-standard gear engagement.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If gear meshing is used to transmit rotation, then the synchronous rotation is achieved, but abnormal noise is generated

Engineering Contradiction:
Improverotation synchronizationVSAvoidabnormal noise
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent introduces a transmission mechanism with bevel gears as an intermediary stage between the first gear and the second rotating component. This intermediate transmission smooths the motion transfer and reduces abnormal noise while maintaining synchronization accuracy.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Reliability

If gear meshing is used to transmit rotation, then the synchronous rotation is achieved, but tooth breakage occurs under external force

Engineering Contradiction:
Improverotation synchronizationVSAvoidgear tooth durability
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The transmission mechanism serves as a protective intermediary that distributes and softens the transmission of forces between the first and second rotating components. This reduces the impact of external forces (such as dropping or collision) on the gear teeth, preventing breakage while maintaining synchronization function.

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

The hinge assembly ensures synchronous rotation of screen components, reduces noise, and prevents gear-related issues, enhancing user experience and durability.

Implementation Method 1

a first elastic member disposed between the first rotating part and the second rotating part

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

damping systems for smooth operation and reduced noise

Methodology Applied
Scientific EffectDamping: Damping

Data Source

PatentEP4325072B1Hinge assembly and terminal product
Publication Date: 2025.07.23 HONOR DEVICE CO LTD
  • EP4325072B1 patent drawingFigure 1
  • EP4325072B1 patent drawingFigure 2
  • EP4325072B1 patent drawingFigure 3

AI summary

A hinge assembly is provided. The hinge assembly includes a base, a first swing arm, a second swing arm, and a slider. The base is provided with a guide groove. The first swing arm includes a first hinge connecting part and a first rotating part. The first swing arm is rotatable relative to the base around a first axis between the first hinge connecting part and the first rotating part. The second swing arm includes a second hinge connecting part and a second rotating part. The second swing arm is rotatable relative to the base around a second axis between the second hinge connecting part and the second rotating part. The second axis is parallel to the first axis. The slider includes a first fastening part, a second fastening part, and an extension part. The extension part is located in the guide groove. The first fastening part is movably connected to the first hinge connecting part. The second fastening part is movably connected to the second hinge connecting part. The first axis and the second axis are parallel to a first direction. The extension part is movable in the guide groove in a second direction perpendicular to the first direction, to drive the first swing arm and the second swing arm to rotate synchronously. This application further provides a terminal product including the hinge assembly.