Helical Gear Hinge Structure for Slim Foldable Display Protection

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Solution Overview

Problem

The existing foldable electronic devices face challenges in reducing space requirements and preventing display damage due to multiple gear structures in their hinge mechanisms, which compromise portability and structural integrity.

Innovation Solution

A hinge structure incorporating a helical gear system that simplifies the gear arrangement by using a first and second rotary member, arm parts, and a fixed bracket, with shaft gears engaged with the helical gear, reducing the need for multiple gear structures and maintaining a gap to protect the display.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple gear structures are used in the hinge mechanism, then the transmission function is achieved, but the space required increases and the device becomes heavier

Engineering Contradiction:

Improvetransmission functionVSAvoidhinge structure weight

Core Design Contradiction:

ReliabilityVSWeight of stationary object

Solution Approach 1:

The patent combines multiple gear structures into a single integrated gear assembly. The gear assembly includes a first gear connected to the first rotary member, a second gear connected to the second rotary member, and a third gear that meshes with both the first and second gears. This merging of multiple transmission elements into one integrated structure reduces the overall weight and space requirements while maintaining the necessary transmission functions for rotating the first and second housings in opposite directions.

Inventive Principle:

Principle #5Merging (Combining)

2Reliability

If multiple gear structures are disposed in the hinge structure, then the transmission operation is achieved, but the space required for the hinge structure increases

Engineering Contradiction:

Improvetransmission operationVSAvoidhinge structure area

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

The patent employs a nested arrangement where the third gear is positioned between and meshes with both the first and second gears. The gear assembly is further nested within the hinge structure, with the first and second rotary members rotatably connected to the hinge body. This nesting of multiple gear elements in a compact, overlapping configuration reduces the overall area occupied by the hinge structure while ensuring proper transmission operation.

Inventive Principle:

Principle #7Nested doll (Nesting)

3Reliability

If multiple gear structures are used, then the rotation control is achieved, but the device becomes more complex and harder to manufacture

Engineering Contradiction:

Improverotation controlVSAvoidgear structure manufacturing

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

By merging multiple gear functions into a single integrated gear assembly with three intermeshing gears, the patent simplifies the manufacturing process. Instead of manufacturing and assembling multiple separate gear mechanisms, the gear assembly can be manufactured as a single unit or pre-assembled module, reducing manufacturing complexity while maintaining precise rotation control for both housings.

Inventive Principle:

Principle #5Merging (Combining)

4Volume of moving object

If gear structures are positioned close to the display, then the device size is reduced, but the display may be damaged by the gear structures

Engineering Contradiction:

Improvedevice volumeVSAvoiddisplay damage risk

Core Design Contradiction:

Volume of moving objectVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a support structure as an intermediary element that positions the gear assembly at a safe distance from the display. The first and second rotary members are rotatably connected to this support structure, which acts as a mediator between the mechanical gear components and the fragile display. This intermediary positioning ensures that the gear structures do not come into contact with or damage the display during rotation operations, while still maintaining a compact overall device volume.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentEP4184900B1Hinge structure comprising helical gear, and electronic device comprising same

Publication Date: 2025.11.12 SAMSUNG ELECTRONICS CO LTD

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AI summary

Disclosed is an electronic device comprising: a first rotation member fastened to a first housing; a second rotation member fastened to a second housing; a first arm part rotating along the first rotation member on the basis of a sliding movement when the first rotation member is rotated; a second arm part rotating along the second rotation member on the basis of a sliding movement when the second rotation member is rotated; a fixing bracket on which the first rotation member and the second rotation member are seated; a helical gear seated on one side of the fixing bracket; a first rotary shaft coupled to the first arm part; a first shaft gear disposed on one side of the first rotary shaft and gear-coupled to one side of the helical gear; a second rotary shaft coupled to the second arm part; and a second shaft gear disposed on one side of the second rotary shaft and gear-coupled to the other side of the helical gear.