Vibration Array for Thin Display Sound Generation

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Solution Overview

Problem

Existing display apparatuses face challenges in achieving a large area for sound generation while maintaining a thin profile and high sound pressure level, as traditional speakers are bulky and piezoelectric elements are fragile and limited in size, making it difficult to produce stereo sound and effectively vibrate in the vertical direction.

Innovation Solution

A vibration device comprising a vibration array with multiple modules spaced less than 3 cm apart, arranged in an i×j form on the display panel's rear surface, which vibrates as a single unit to enhance sound characteristics and pressure level, allowing for a larger area and improved sound localization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional speakers are used in display apparatuses, then sound generation function is provided, but the speaker occupies space and limits design flexibility

Engineering Contradiction:
Improvesound generation functionVSAvoidspeaker space
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The patent merges the speaker function with the display panel by making the display panel itself serve as the vibration element. The backlight unit structure is utilized as the speaker component, eliminating the need for a separate speaker and reducing overall device volume while maintaining sound generation capability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The display panel is designed to perform multiple functions: it serves as both the display surface and the vibration element for sound generation. The backlight unit structure is configured to function as both the light source assembly and the speaker component, enabling one element to fulfill multiple roles.

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

2Length of stationary object

If piezoelectric elements are used to reduce thickness, then thinness is achieved, but the elements are fragile and difficult to scale to large areas

Engineering Contradiction:
ImprovethicknessVSAvoidfragility and reliability
Core Design Contradiction:
Length of stationary objectVSReliability

Solution Approach 1:

Instead of using fragile piezoelectric elements, the patent utilizes the existing backlight unit structure as a copy or alternative implementation of the speaker function. The backlight components (light guide plate, diffuser plates, reflector) are repurposed to serve as the vibration element, eliminating the need for fragile piezoelectric materials while maintaining the thin profile.

Inventive Principle:
Principle #26Copying

3Length of stationary object

If piezoelectric elements are used for sound reproduction, then thinness is achieved, but sound pressure level and stereo sound capability are limited

Engineering Contradiction:
ImprovethicknessVSAvoidsound pressure level
Core Design Contradiction:
Length of stationary objectVSPower

Solution Approach 1:

The patent combines multiple backlight components (light guide plate, first diffuser plate, second diffuser plate, reflector) to form a unified vibration structure that functions as the speaker. This merged structure has larger surface area and greater structural integrity, enabling higher sound pressure levels and stereo sound capability while maintaining thinness.

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

The solution enables a display apparatus to produce high sound pressure levels and stereo sound with enhanced sound localization, overcoming the limitations of traditional speakers and fragile piezoelectric elements by utilizing a modular vibration array that vibrates as a single unit, thus increasing the effective area for sound generation.

Implementation Method 1

a piezoelectric layer disposed between the first electrode layer and the second electrode layer, the piezoelectric layer having a piezoelectric characteristic

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Data Source

PatentEP3890351B1Vibration device and display apparatus including the same
Publication Date: 2024.11.06 LG DISPLAY CO LTD
  • EP3890351B1 patent drawingFigure 1~2
  • EP3890351B1 patent drawingFigure 3~4
  • EP3890351B1 patent drawingFigure 5A~5B

AI summary

A vibration device enabling a large area and a display apparatus including the vibration device are provided. The vibration device may be configured to include a vibration array including a plurality of vibration modules which are spaced apart from one another by a first interval of less than 3 cm in a first direction.