Flexible Hinge Assembly for Wrinkle-Free Foldable Displays

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Solution Overview

Problem

Existing foldable flexible display panels often wrinkle during folding and struggle to maintain a consistent bent angle, lacking control over the folding process and returning to their original shape.

Innovation Solution

A foldable module with a flexible hinge comprising rotating shafts, fixed washers, biasing gaskets, movable washers, and disc springs, which provide adjustable torque and axial friction to maintain a predetermined angular range, integrated with a metal frame for shape-memory and high elasticity, preventing wrinkles and allowing arbitrary positioning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If torque-free hinges are used for folding flexible display panels, then the device can be folded, but the display panel becomes wrinkled and the bending angle cannot be maintained

Engineering Contradiction:
Improvefolding capabilityVSAvoidwrinkle prevention and angle maintenance
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The hinge assembly pre-applies torque through disc springs and biasing gaskets before folding occurs, creating a controlled bending moment that prevents wrinkles from forming during the folding process. The preliminary torque ensures the display panel bends along a predetermined radius without creasing.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The hinge assembly changes the torque parameter dynamically during folding operation. The disc springs and biasing gaskets provide variable torque based on the bending angle, maintaining optimal pressure to prevent wrinkles while allowing smooth folding motion throughout the range of motion.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If flexible display panels are bent without a flexible hinge, then the structure remains simple, but the bending angle is not easy to control and maintain

Engineering Contradiction:
Improvehinge structureVSAvoidbending angle control
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The hinge assembly is self-regulating through the elastic properties of disc springs and biasing gaskets. These components automatically adjust the torque to maintain the predetermined bending angle without requiring external control systems, achieving precise angle control while keeping the overall structure relatively simple.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The hinge assembly enforces a predetermined curvature radius on the flexible display panel during bending. By designing the hinge geometry to match the desired bending radius, the system achieves consistent and controllable bending angles through the natural curvature imposed by the hinge structure.

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Device complexity

If natural bending without support is used, then the device structure is simple, but the bent panel returns to its original shape

Engineering Contradiction:
Improvesupport structureVSAvoidbent shape maintenance
Core Design Contradiction:
Device complexityVSStability of the object's composition

Solution Approach 1:

The hinge assembly acts as a counterbalancing support that opposes the natural elastic recovery force of the flexible display panel. The disc springs and biasing gaskets provide continuous torque to counteract the panel's tendency to return to its original flat shape, maintaining the bent configuration stably.

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

Solution Approach 2:

The hinge assembly serves as an intermediary between the flexible display panel and the external environment. It mediates the force balance by providing controlled torque through disc springs and biasing gaskets, allowing the panel to maintain its bent shape against elastic recovery forces without requiring rigid external support structures.

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 solution enables flexible display devices to bend and fold without wrinkling, maintain arbitrary positions within a predetermined range, and quickly restore to their original shape, enhancing performance by preventing wrinkles and ensuring consistent bending angles.

Implementation Method 1

the disc springs provide axial friction

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

have a shape-memory effect and high elasticity, and quickly restored to the original state

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3683787B1Folding component and flexible display device
Publication Date: 2022.06.08 WUHAN CHINA STAR OPTOELECTRONICS SEMICONDUCTOR DISPLAY TECHNOLOGY CO LTD
  • EP3683787B1 patent drawingFigure 1~2B
  • EP3683787B1 patent drawingFigure 2C~3
  • EP3683787B1 patent drawingFigure 4~5

AI summary

A folding component and a flexible display device. The folding component comprises: a metal frame (20) for fixing a flexible display panel (10) to be assembled; a protective housing (30) for fixing the flexible display panel (10) to be assembled and the metal frame (20); and a flexible hinge (40) fixed on the protective housing (30). The flexible hinge (40) comprises: a rotating shaft, a fixed washer, a pressure distribution washer, a moveable washer, and a disk spring (460), and achieves limiting of the flexible hinge (40) to within a preset angular range.