Haptic Feedback for Foldable-Bendable Displays

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Solution Overview

Problem

Conventional electronic devices lack intuitive and realistic haptic feedback mechanisms for user interactions, particularly with flexible and foldable displays, which fail to effectively translate digital events into physical sensations, making interactions less immersive and less intuitive compared to real-world experiences.

Innovation Solution

A haptically-enabled foldable-bendable display system that incorporates programmable vibrotactile and kinesthetic haptics, using a combination of sensors and actuators to interpret user gestures and provide tactile and force feedback, simulating real-world interactions such as page turning and object manipulation, by adjusting the stiffness and deformability of the display based on user input and application requirements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional actuators (ERM, LRA, piezoelectric) are used to provide haptic feedback, then vibration and tactile effects can be generated, but the feedback lacks realism and immersion for foldable-bendable display interactions

Engineering Contradiction:
Improvehaptic feedback realismVSAvoidhaptic system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies dynamics by making the display's mechanical properties adjustable in real-time. The system dynamically changes the stiffness and deformability of the display surface using controlled deformation mechanisms, allowing the display to transition between rigid and flexible states to provide realistic haptic feedback for different interaction scenarios

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes physical parameters of the display by modifying its deformation characteristics. Through controlled deformation of the display surface, the system alters stiffness, flexibility, and mechanical resistance parameters to simulate real-world tactile sensations, enhancing haptic feedback realism without adding complex separate actuator systems

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If the display is made highly flexible and deformable to enable foldable-bendable interactions, then user gesture input capability is improved, but the display becomes too soft to provide adequate force feedback and structural stability

Engineering Contradiction:
Improvedisplay flexibilityVSAvoiddisplay structural stability
Core Design Contradiction:
Adaptability or versatilityVSStrength

Solution Approach 1:

The display structure is made dynamic, allowing it to switch between flexible and rigid states as needed. During user interaction, the display can deform to capture gestures, then stabilize to provide force feedback, creating a dynamic balance between flexibility and structural stability

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the mechanical parameters of the display on-demand. By controlling the deformation state of the display surface, it can transition from a soft, deformable state (for gesture input) to a stiffer state (for providing force feedback and maintaining structural integrity during interaction)

Inventive Principle:
Principle #35Parameter changes

3Force

If the display maintains a rigid structure to provide stable force feedback, then haptic resistance is improved, but the display cannot be deformed for gesture recognition and interaction

Engineering Contradiction:
Improvehaptic resistanceVSAvoidgesture recognition capability
Core Design Contradiction:
ForceVSEase of operation

Solution Approach 1:

The display's mechanical properties are made dynamic, allowing it to adapt its rigidity based on interaction context. The system can present a rigid surface for force feedback during certain phases of interaction, then become deformable for gesture recognition in other phases, optimizing both haptic resistance and ease of operation

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the stiffness parameter of the display dynamically. By controlling the deformation state, it can increase rigidity to provide haptic resistance when force feedback is needed, then decrease rigidity to enable deformation for gesture recognition, resolving the contradiction between these two requirements

Inventive Principle:
Principle #35Parameter changes

4Reliability

If sensors and actuators are added to provide haptic feedback, then interaction realism is improved, but device complexity and manufacturing difficulty increase

Engineering Contradiction:
Improveinteraction realismVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The display structure serves multiple functions simultaneously. It acts as both the display surface and the haptic feedback mechanism through controlled deformation. By making the display itself deformable and responsive, the system eliminates the need for separate complex haptic actuator systems, reducing manufacturing complexity while maintaining interaction realism

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The display structure provides its own haptic feedback capability through controlled deformation. Rather than requiring external actuators to generate haptic effects, the display uses its own deformable structure to provide tactile feedback, simplifying the overall system architecture and easing manufacturing

Inventive Principle:
Principle #25Self-service

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

Enhances user interaction experience by providing intuitive and realistic haptic feedback, making digital interactions more immersive and natural, and effectively conveying information through tactile and kinesthetic responses, thereby expanding the user interface design space and improving the usability of flexible and foldable displays.

Implementation Method 1

many devices utilize some type of actuator or haptic output device. Known actuators used for this purpose include an electromagnetic actuator such as an solenoid actuator

Methodology Applied
Scientific EffectElectromagnetic actuation: Electromagnetic Induction

Implementation Method 2

The 'Bookisheet' interface, which can be used for flexible displays, consists of two connected thin plastic sheets and two respectively attached bend sensors

Methodology Applied
Scientific EffectBending detection:

Data Source

PatentEP2796976B1Haptic feedback for interactions with foldable-bendable displays
Publication Date: 2020.01.22 IMMERSION CORP
  • EP2796976B1 patent drawingFigure 1
  • EP2796976B1 patent drawingFigure 2
  • EP2796976B1 patent drawingFigure 3

AI summary

A flexible device includes a bendable-foldable display that has bendable flaps connected by a hinge. The display has sensors for detecting a folding characteristic between the at least two flaps and for detecting a bending characteristic in at least one flap. The display has a haptic system with haptic output devices, where the haptic system receives input from the sensors indicating deformation of the bendable-foldable display device. A flexible device also includes bendable, foldable, or rollable displays that have sensors and actuators to augment user interaction with the device. Based on one or more measurements provided by the input, the haptic system interprets the input to determine deformation characteristics of the bendable-foldable display device. The haptic system generates haptic feedback based on the deformation characteristics.