Foldable Hinge Cam Structure With Viscoelastic Detent Damping

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Solution Overview

Problem

In foldable electronic devices, reducing the thickness of the hinge device weakens the pressing force and detent force, leading to unintended switching between folded and unfolded states.

Innovation Solution

A hinge device with a bracket, rotators, cam structures, and elastic members, along with a buffer member made of a different material, enhances the pressing force and maintains specific angles through improved operational feel and vibration damping.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of moving object

If the thickness of the hinge device is reduced, then the thickness of the electronic device is reduced, but the pressing force through the elastic member is reduced, causing free stop and detent functions to fail

Engineering Contradiction:
Improvethickness of electronic deviceVSAvoidpressing force
Core Design Contradiction:
Length of moving objectVSForce

Solution Approach 1:

The patent introduces a buffer member made of a material different from the elastic member, specifically a viscoelastic material, to create a composite pressing force system. This composite structure combines the elastic restoring force of the elastic member with the vibration damping and force supplementation of the viscoelastic buffer member, thereby maintaining adequate pressing force even when the hinge device thickness is reduced.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent changes the material parameters by introducing a viscoelastic material with specific damping characteristics. The buffer member's material properties are selected to provide appropriate force supplementation across different operating conditions, allowing the system to maintain functional performance with reduced thickness.

Inventive Principle:
Principle #35Parameter changes

2Length of moving object

If the thickness of the elastic member is reduced to reduce device thickness, then the detent force is weakened, but the electronic device may switch states regardless of user intention

Engineering Contradiction:
Improvethickness of elastic memberVSAvoidstate maintenance reliability
Core Design Contradiction:
Length of moving objectVSReliability

Solution Approach 1:

The buffer member made of viscoelastic material works in conjunction with the elastic member to create a composite force system. The viscoelastic material's characteristics provide supplementary force that strengthens the detent effect, ensuring reliable state maintenance even when the elastic member thickness is reduced.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The buffer member acts as a pre-positioned cushioning element that supplements the pressing force before the cam structure and cam slide engage. This prior cushioning ensures that adequate force is available to maintain the detent effect and prevent unintended state switching throughout the operation range.

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

3Device complexity

If a single elastic member is used, then the structure is simple, but vibrations occur during folding and unfolding operations

Engineering Contradiction:
Improvehinge device structureVSAvoidvibrations
Core Design Contradiction:
Device complexityVSObject-generated harmful factors

Solution Approach 1:

The introduction of a buffer member made of viscoelastic material creates a composite damping system. The viscoelastic material's inherent vibration damping characteristics absorb and dissipate vibrations generated during folding and unfolding operations, significantly reducing harmful vibrations while adding only one additional component.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent converts the potentially harmful vibrations generated during hinge operation into beneficial energy dissipation through the viscoelastic buffer member. The vibration energy is absorbed and converted into heat through the material's viscoelastic damping characteristics, transforming a harmful effect into a beneficial vibration reduction mechanism.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 device maintains free stops and unfolded/folded states at specific angles with increased pressing force and reduces vibrations, enhancing operational reliability.

Implementation Method 1

elastic members disposed between one surface of the bracket and the cam slide to press the cam slide in the first direction

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

a buffer member made of a material different from that of the elastic member and disposed between one surface of the bracket and the cam slide to press the cam slide in a first direction

Methodology Applied
Scientific EffectVibration damping: Damping

Data Source

PatentEP4685608A1Electronic apparatus including hinge device
Publication Date: 2026.01.28 SAMSUNG ELECTRONICS CO LTD
  • EP4685608A1 patent drawingFigure 1A
  • EP4685608A1 patent drawingFigure 1B
  • EP4685608A1 patent drawingFigure 2A

AI summary

A hinge device according to an embodiment of the present invention may comprise: a bracket that includes a first connection part and a second connection part spaced apart from the first connection part; a first rotator that includes a first rotating part connected to a first connection part of the bracket and rotating relative to the bracket, and a first cam structure formed on the first rotating part; a second rotator that includes a second rotating part connected to the second connection part of the bracket and rotating relative to the bracket, and a second cam structure formed on the second rotating part; a cam slide that is disposed on the bracket, includes a first cam part engaging with the first cam structure and a second cam part engaging with the second cam structure, and moves in the first axial direction according to the rotation of the first rotator and the second rotator; an elastic member that is disposed between the cam slide and one surface of the bracket and presses the cam slide in a first direction; and a shock-absorbing member that is made of a different material than the elastic member and is disposed between the cam slide and the one surface of the bracket and presses the cam slide in the first direction. Various other embodiments are also possible.