Hinge Structure Recess Integration for Foldable Device Thickness

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Solution Overview

Problem

In foldable electronic devices, the spacing between the hinge structure and the flexible display to prevent collision in a folding motion increases the device's thickness, and belleville springs used for axial pressure have a shorter service life compared to coil springs, necessitating a larger hinge structure and increased thickness.

Innovation Solution

A hinge structure with a fixed bracket, rotary brackets, and elastic members that allow for compact design, prevent electrical conduction, and reduce gear wear and noise, featuring a compact design and increased metal layer areas for improved surface quality, while preventing connecting shaft separation from internal gears.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If spacing is increased between the hinge structure and the flexible display to prevent collision in folding motion, then collision prevention is improved, but the device thickness increases

Engineering Contradiction:
Improvecollision preventionVSAvoiddevice thickness
Core Design Contradiction:
ReliabilityVSLength of moving object

Solution Approach 1:

The patent places the hinge structure inside a recess formed on the rear surface of the flexible display. This nesting arrangement allows the hinge to be embedded within the display's thickness rather than adding to it externally, enabling collision prevention while maintaining a compact overall device thickness.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent transitions from a planar spacing approach to a three-dimensional recess integration. By forming a recess on the rear surface of the flexible display and positioning the hinge within this recess, the solution moves the hinge structure into a different spatial dimension (inside the display thickness) rather than maintaining it as a separate external component.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If belleville springs are used for axial pressure to prevent connecting shaft separation, then separation prevention is improved, but service life decreases compared to coil springs

Engineering Contradiction:
Improveconnecting shaft separation preventionVSAvoidspring service life
Core Design Contradiction:
ReliabilityVSDuration of action of moving object

Solution Approach 1:

The patent adopts belleville springs despite their shorter service life, accepting this limitation as a trade-off for achieving the critical function of preventing connecting shaft separation. The design prioritizes the immediate reliability of connection maintenance over long-term component durability.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The belleville springs are positioned to apply axial pressure beforehand to prevent connecting shaft separation. The springs are pre-compressed or positioned to immediately counteract any separation forces that may occur during hinge operation, providing proactive protection against connection failure.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Duration of action of moving object

If belleville spring area is increased to ensure sufficient service life, then service life is improved, but the hinge structure size and device thickness increase

Engineering Contradiction:
Improvespring service lifeVSAvoidhinge structure thickness
Core Design Contradiction:
Duration of action of moving objectVSLength of moving object

Solution Approach 1:

The hinge structure, including the belleville springs, is nested within a recess on the rear surface of the flexible display. This embedding approach allows the hinge components to occupy space that would otherwise be part of the display's internal structure, preventing additional thickness from being added to the overall device.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The solution moves the hinge structure into the third dimension by creating a recess on the rear surface of the flexible display. This allows the hinge and its components (including larger-area belleville springs) to be positioned within the display's thickness rather than extending beyond it, effectively using the display's own depth as the hinge's housing space.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 structure achieves a compact design, reduces the overall thickness of the electronic device, enhances surface quality, prevents electrical shock, and improves performance by reducing gear wear and noise.

Implementation Method 1

a first elastic member, at least part of which is disposed in the first through-hole, the first elastic member being formed such that one side of the first elastic member is supported by the second support part and an opposite side of the first elastic member presses the at least one fixed bracket towards the first rotary bracket

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

a first gear formed between the first support part and the second support part... a first internal gear formed on an inner wall of the first circular arc-shaped opening and engaged with the first gear

Methodology Applied
Scientific EffectGear mechanism: Gear

Implementation Method 3

a first connecting shaft extending in a first direction through an interior of the first through-hole and including a first support part formed on an end portion of the first connecting shaft

Methodology Applied
Scientific EffectMechanical force transmission: Mechanical Force

Data Source

PatentEP3909227B1Hinge structure and electronic device including the same
Publication Date: 2024.09.04 SAMSUNG ELECTRONICS CO LTD
  • EP3909227B1 patent drawingFigure 1a
  • EP3909227B1 patent drawingFigure 1b~1c
  • EP3909227B1 patent drawingFigure 1d~2

AI summary

A hinge structure for an electronic device is disclosed, including: a fixed bracket including a first and second through-hole, a first connecting shaft inserted into the first through-hole, a first rotary bracket disposed between a fixed bracket and a support part, a first elastic member disposed partially in the first through-hole and supported by the second support part and pressing a fixed bracket towards the first rotary bracket, a second connecting shaft inserted into the second through-hole, a second rotary bracket disposed between a fixed bracket and a support part, a second elastic member disposed partially in the second through-hole and supported by another support part and pressing a fixed bracket towards the second rotary bracket, wherein at least one fixed bracket is disposed between the first rotary bracket and the second rotary bracket.