Piezoelectric Display Actuator for Integrated Audio and Haptic Output

Solution Overview

Problem

Existing portable devices face challenges in providing effective haptic feedback and audio functionality due to the need for separate vibrator and electro-acoustic transducers, which increase cost, volume, and susceptibility to contaminants, while also requiring significant current consumption and complex signal processing.

Innovation Solution

A flexible membrane connects the display to the device's cover, allowing for the combination of haptic and audio signals, enabling the display to function as both a touch screen and a speaker by using piezoelectric actuators that flex and transmit force without damping, thus providing enhanced user interaction and acoustic wave generation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If separate vibrator and electro-acoustic transducers are used for haptic feedback and audio functionality, then haptic and audio output can be provided, but device volume and cost increase

Engineering Contradiction:

Improvehaptic feedback effectivenessVSAvoiddevice volume

Core Design Contradiction:

ReliabilityVSVolume of stationary object

Solution Approach 1:

The patent combines the haptic feedback function and audio speaker function into a single integrated system using the display assembly. The display assembly is configured to receive both haptic signals and audio signals, and a single actuator converts these signals into mechanical movements that produce both haptic feedback and acoustic waves. This eliminates the need for separate vibrator and speaker components, reducing device volume while maintaining functional effectiveness.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The display assembly is designed to perform multiple functions: it serves as the visual display, the touch-sensitive input surface, the haptic feedback mechanism, and the audio speaker. By making the display assembly universal and multi-functional, the patent eliminates the need for dedicated separate components for haptic and audio functions, thereby reducing overall device volume and component count.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If separate vibrator and electro-acoustic transducers are used for haptic feedback and audio functionality, then haptic and audio output can be provided, but device cost increases

Engineering Contradiction:

Improvehaptic feedback effectivenessVSAvoiddevice cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent merges the haptic feedback function and audio speaker function into a single integrated system using the display assembly. The display assembly is configured to receive both haptic signals and audio signals, and a single actuator converts these signals into mechanical movements that produce both haptic feedback and acoustic waves. This eliminates the need for separate vibrator and speaker components, reducing device volume while maintaining functional effectiveness.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The display assembly is designed to perform multiple functions: it serves as the visual display, the touch-sensitive input surface, the haptic feedback mechanism, and the audio speaker. By making the display assembly universal and multi-functional, the patent eliminates the need for dedicated separate components for haptic and audio functions, thereby reducing overall device volume and component count.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Reliability

If electro-acoustic transducers are used for audio output, then audio can be generated, but the transducers attract contaminants reducing device lifetime

Engineering Contradiction:

Improveaudio generation capabilityVSAvoiddevice lifetime

Core Design Contradiction:

ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The patent extracts the audio generation function from the traditional electro-acoustic transducer (speaker) and relocates it to the display assembly. By using the display assembly as the acoustic radiator and driven by a piezoelectric actuator, the system eliminates the need for a separate electro-acoustic transducer that would attract iron particles and contaminants, thereby extending device lifetime while maintaining audio generation capability.

Inventive Principle:

Principle #2Taking out (Extraction)

4Ease of operation

If device haptic feedback is used to provide click feedback, then mechanical feedback is simulated, but significant current is required to generate sufficient feedback force

Engineering Contradiction:

Improvemechanical feedback simulationVSAvoidcurrent consumption

Core Design Contradiction:

Ease of operationVSUse of energy by moving object

Solution Approach 1:

The patent combines the haptic feedback function and audio speaker function into a single integrated system using the display assembly. The display assembly is configured to receive both haptic signals and audio signals, and a single actuator converts these signals into mechanical movements that produce both haptic feedback and acoustic waves. This eliminates the need for separate vibrator and speaker components, reducing device volume while maintaining functional effectiveness.

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

This solution enhances user experience by providing effective haptic feedback and audio generation without the need for additional transducers, reducing volume and cost, and minimizing the risk of contamination, while maintaining mechanical support for the display.

Implementation Method 1

A display assembly for use in apparatus, the display assembly comprising a display, wherein the display is configured to receive both a haptic signal and an audio signal, and wherein the display assembly further comprises a piezoelectric actuator configured to convert the haptic signal and the audio signal to mechanical movements of the display

Methodology Applied

Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

A flexible membrane connects the display to the device's cover, allowing for the combination of haptic and audio signals, enabling the display to function as both a touch screen and a speaker by using piezoelectric actuators that flex and transmit force without damping

Methodology Applied

Scientific EffectElasticity: Elasticity

Implementation Method 3

the display is configured to receive both a haptic signal and an audio signal... providing tactile feedback through the display and also generating acoustic waves suitable for earpiece or speaker replacement operations

Methodology Applied

Scientific EffectVibration: Vibration

Data Source

PatentEP2659337B1A display apparatus producing audio and haptic output

Publication Date: 2021.07.28 NOKIA TECHNOLOGIES OY

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AI summary

An apparatus comprising; a first part configured to form at least part of the case of the apparatus; a second part configured to form at least part of the display for the apparatus; at least one actuator coupled to the second part and configured to apply a force to the second part to generate a displacement of the second part; drive circuitry coupled to the at least one actuator and configured to drive the actuator to produce both audio and haptic outputs; and a suspender configured to couple the first part and the second part.