Under-Panel Dual Actuators for Display Audio and Haptic Feedback

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Solution Overview

Problem

Existing display devices face challenges in providing both sound output and haptic feedback without compromising the display area, as they often require a front speaker that occupies valuable space.

Innovation Solution

The display device incorporates two sound generating devices, a piezoelectric actuator for high frequencies and a linear resonant actuator for low frequencies, positioned beneath the display panel, allowing for sound generation and haptic feedback without a front speaker, thus increasing the display area.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a front speaker is provided on the display device, then sound output quality is improved, but the display area is reduced

Engineering Contradiction:
Improvesound output qualityVSAvoiddisplay area
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

The patent moves the speaker from the front surface (2D plane) to the back surface of the display panel, utilizing the third dimension (thickness direction) to resolve the space conflict. This allows the display area on the front surface to be maximized while sound generation functions are maintained on the back surface through vibration of the display panel.

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

2Area of stationary object

If sound generating devices are integrated beneath the display panel, then display area is increased, but sound pressure level may be reduced

Engineering Contradiction:
Improvedisplay areaVSAvoidsound pressure level
Core Design Contradiction:
Area of stationary objectVSPower

Solution Approach 1:

The display panel serves dual functions: as the visual display surface and as the sound generation membrane. By utilizing the display panel itself for sound generation through vibration, the system eliminates the need for separate front-facing speakers while maintaining sound output capability, thereby maximizing display area without significant loss in sound pressure level.

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

3Adaptability or versatility

If haptic feedback is added to sound generation functions, then user interaction capability is improved, but device complexity increases

Engineering Contradiction:
Improveuser interaction capabilityVSAvoiddevice complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The same sound generating devices (first and second speakers) are used for both sound output and haptic feedback functions. The display panel vibrates to provide both audio output and tactile feedback, eliminating the need for separate haptic actuator components and reducing overall device complexity while enhancing user interaction capabilities.

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

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 high-quality sound output across frequency ranges and provides haptic feedback while maximizing the display area by eliminating the need for a front speaker.

Implementation Method 1

the first sound generating device includes a piezoelectric actuator

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

the second sound generating device includes an actuator by pressing a mass connected to a spring via a voice coil

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 3

an actuator by pressing a mass connected to a spring via a voice coil

Methodology Applied
Scientific EffectResonance: Resonance

Data Source

PatentEP3621313B1Display device and method of driving the same
Publication Date: 2025.07.16 SAMSUNG DISPLAY CO LTD
  • EP3621313B1 patent drawingFigure 1
  • EP3621313B1 patent drawingFigure 2
  • EP3621313B1 patent drawingFigure 3

AI summary

A display device including: a display panel; and first and second sound generating device configured to generating sounds and vibrate the display panel, wherein the first sound generating device may have a higher sound pressure level than the second sound generating device in a first frequency range, and the second sound generating device may have a higher sound pressure level than the first sound generating device in a second frequency range lower than the first frequency range. A method of driving a display device in sound generating and haptic modes also is disclosed.