Foldable Display Hinge Structure for Stable Folded-State Torque

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Solution Overview

Problem

Foldable electronic devices with flexible displays face issues with maintaining a desired folded state due to increased restoring force as the display size increases, leading to defects in folding and unfolding motions.

Innovation Solution

A hinge structure that provides torque sufficient to cancel out the restoring force of the display without increasing the device's thickness, incorporating rotary structures, sliding structures, and friction mechanisms to stabilize the folding motion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If the size of the flexible display is increased to provide a wider screen, then the screen area is improved, but the restoring force increases causing defects in folding motion

Engineering Contradiction:
Improvescreen areaVSAvoidrestoring force
Core Design Contradiction:
Area of stationary objectVSForce

Solution Approach 1:

The hinge structure incorporates a counterbalancing mechanism that generates a counter-force opposite to the restoring force of the flexible display. This counter-force compensates for the increased restoring force, allowing the device to maintain stable folding motion and desired folded states even with larger display sizes.

Inventive Principle:
Principle #8Anti-weight (Counterweight)

2Stability of the object's composition

If a hinge structure is designed to provide sufficient torque to cancel restoring force, then the stability of folded state is improved, but the thickness of the device increases

Engineering Contradiction:
Improvestability of folded stateVSAvoidthickness of device
Core Design Contradiction:
Stability of the object's compositionVSLength of stationary object

Solution Approach 1:

The hinge structure utilizes a multi-dimensional mechanical design that distributes the torque-generating components across different spatial dimensions. By arranging friction mechanisms and rotary structures in a compact three-dimensional configuration, the design achieves sufficient counter-torque without extending the overall thickness of the device.

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

Solution Approach 2:

The hinge structure introduces intermediary friction mechanisms that act as mediators between the display and the counterbalancing system. These friction mechanisms provide the necessary torque to counteract restoring force while maintaining a compact form factor, avoiding direct thickening of the device structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of operation

If the hinge structure incorporates friction mechanisms to stabilize folding motion, then the control of folded state is improved, but the device complexity increases

Engineering Contradiction:
Improvecontrol of folded stateVSAvoidstructure complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The hinge structure merges the friction mechanisms, rotary structures, and counterbalancing elements into an integrated assembly. By combining these functions into a unified hinge unit rather than separate components, the design achieves stable folding motion control while minimizing the increase in overall device complexity.

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 hinge structure effectively maintains the desired folded state of the foldable electronic device by counteracting the restoring force, ensuring stable folding and unfolding motions without thickness augmentation.

Implementation Method 1

a first friction portion generating friction with the first friction plate and a second friction portion generating friction with the second friction plate

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4155562B1Hinge structure and electronic device including same
Publication Date: 2025.01.08 SAMSUNG ELECTRONICS CO LTD
  • EP4155562B1 patent drawingFigure 1
  • EP4155562B1 patent drawingFigure 2A
  • EP4155562B1 patent drawingFigure 2B

AI summary

A hinge structure is provided. The hinge structure includes a fixed structure including a first guide rail and a second guide rail, a center of an arc of the first guide rail is a first axis of rotation parallel to an axial direction and a center of an arc of the second guide rail is a second axis of rotation parallel to the axial direction, a first rotary structure including a first guide portion accommodated in the first guide rail and a first helical groove extending around and along the first axis of rotation, a second rotary structure including a second guide portion accommodated in the second guide rail and a second helical groove extending around and along the second axis of rotation, and a sliding structure including a first guide protrusion accommodated in the first helical groove and a second guide protrusion accommodated in the second helical groove.