Roller Display Synchronized Foldable Links and Gas Spring Torque

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Solution Overview

Problem

Existing display devices face challenges in stably rolling and unrolling flexible OLED displays around a roller due to issues with torque control and mechanical stability, particularly in maintaining symmetry and preventing damage from external impacts.

Innovation Solution

A display device design incorporating a housing with a roller, foldable links, motors, and a gas spring system, where synchronized control of left and right foldable links and motors, along with a gear mechanism and position sensing units, ensures stable unrolling and rolling of the display unit while providing the necessary torque and force to manage the flexible display.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If a flexible display is rolled around a roller, then the display device can be compact and portable, but it becomes difficult to stably roll or unroll the flexible display

Engineering Contradiction:
ImprovecompactnessVSAvoidstable rolling
Core Design Contradiction:
Volume of moving objectVSEase of operation

Solution Approach 1:

The patent employs foldable links with rotational joints that dynamically adjust during the unrolling process. The links transition from a folded state to an extended state, enabling controlled movement of the display panel from the rolled position to the unfolded position while maintaining stability throughout the transition.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The foldable links act as intermediary mechanical elements between the motor and the display panel. These links transmit and transform the rotational motion from the motor into the coordinated movement required for stable unrolling, mediating the force transmission and motion control.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If motors are used to pivot foldable links for unrolling the display unit, then controlled movement is achieved, but torque control and mechanical stability become challenging

Engineering Contradiction:
Improvecontrolled movementVSAvoidmechanical stability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The gas spring serves as a counterweight mechanism that provides upward force to balance the weight of the foldable links and display panel during unrolling. This counterbalancing force reduces the torque requirement for the motor and maintains mechanical stability throughout the movement, preventing uncontrolled motion or stalling.

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

Solution Approach 2:

The gas spring utilizes pneumatic pressure to generate the counterbalancing force. By compressing and expanding the gas spring, the system provides controlled mechanical assistance during the unrolling and rolling operations, enhancing stability and reducing the burden on the motor system.

Inventive Principle:
Principle #29Pneumatics and hydraulics

3Stability of the object's composition

If synchronized control of left and right foldable links is implemented, then left-right symmetry is maintained, but control complexity increases

Engineering Contradiction:
ImprovesymmetryVSAvoidcontrol complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The controller integrates the control of left and right motors into a unified control system. By merging the control functions and coordinating both motors through a single control unit, the system maintains synchronized operation and left-right symmetry while managing complexity through centralized control logic.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The system employs feedback mechanisms where the controller monitors the position and operation of both foldable links and adjusts motor commands accordingly. This feedback control ensures that both sides remain synchronized and symmetric during unrolling and rolling operations, automatically compensating for any deviations.

Inventive Principle:
Principle #23Feedback

4Force

If a gear mechanism is used to obtain required torque, then mechanical advantage is achieved, but device complexity increases

Engineering Contradiction:
ImprovetorqueVSAvoidmechanical complexity
Core Design Contradiction:
ForceVSDevice complexity

Solution Approach 1:

The gas spring replaces a purely mechanical torque multiplication system (such as complex gear trains) with a pneumatic-mechanical system. The gas spring directly provides the necessary counterbalancing force and torque assistance through its elastic properties, eliminating the need for additional gear mechanisms while achieving the required mechanical advantage.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 stable unrolling and rolling of the display unit while maintaining left-right symmetry, providing the required torque and force to manage the flexible OLED display, thus addressing the mechanical stability and damage prevention issues.

Implementation Method 1

a gas spring including a cylinder pivotally coupled to the housing, and a piston reciprocating between the inside and the outside of the cylinder and pivotally coupled to the first foldable link

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

a shock absorber that is disposed inside the housing and is in contact with the lower link as the first foldable link is folded

Methodology Applied
Scientific EffectDamping: Damping

Implementation Method 3

a first rotary encoder sensing an angular displacement of the first drive shaft. The controller may obtain information about the angular displacement of the first drive shaft from the first rotary encoder and control the first motor

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP3690868B1Display device
Publication Date: 2022.06.22 LG ELECTRONICS INC
  • EP3690868B1 patent drawingFigure 1
  • EP3690868B1 patent drawingFigure 2
  • EP3690868B1 patent drawingFigure 3

AI summary

A display device is disclosed. The display device includes a housing, a roller installed inside the housing, a display unit rolled or unrolled around the roller, a first foldable link and a second foldable link opposite to each other, the first foldable link and the second foldable link each including one end pivotally coupled to the housing and another end pivotally coupled to an upper part of the display unit, a first motor and a second motor installed inside the housing and respectively pivoting the first foldable link and the second foldable link, and a controller configured to control the first motor and the second motor so that the first foldable link and the second foldable link are synchronized.