Display Panel Cavity Structure for Call Privacy Sound Isolation

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Solution Overview

Problem

Existing communication devices with sound-producing display panels suffer from sound leakage due to vibrations propagating away from the screen, compromising privacy during calls.

Innovation Solution

A display panel design incorporating a structural member and a piezoelectric sound-generating unit with a gap in the thickness direction to prevent vibration propagation away from the display panel, forming a cavity that reduces sound leakage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If the piezoelectric sound-generating unit is directly connected to the structural member, then the sound generation efficiency is improved, but sound leakage occurs and privacy is compromised

Engineering Contradiction:
Improvesound generation efficiencyVSAvoidsound leakage
Core Design Contradiction:
PowerVSObject-generated harmful factors

Solution Approach 1:

An adhesive layer is introduced as an intermediary between the piezoelectric sound-generating unit and the structural member. This adhesive layer serves as a vibration isolation component that prevents direct rigid connection, thereby blocking the transmission path of vibrations to the non-display side while still allowing the sound-generating unit to function effectively on the display side.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The connection characteristics between the piezoelectric sound-generating unit and the structural member are changed by using an adhesive layer with specific vibration isolation properties. This modifies the mechanical coupling parameters, allowing selective transmission of vibrations - enabling sound generation toward the display side while preventing leakage toward the non-display side.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If a rigid connection is made between the piezoelectric sound-generating unit and the structural member, then the sound production capability is enhanced, but vibration propagation to the non-display side increases

Engineering Contradiction:
Improvesound production capabilityVSAvoidvibration propagation
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The adhesive layer acts as a mediator that provides controlled mechanical coupling. It maintains sufficient connection for reliable sound production on the display side while simultaneously acting as a vibration barrier to prevent unwanted propagation to the non-display side, thus resolving the contradiction between connection rigidity and vibration isolation.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The connection between the piezoelectric sound-generating unit and the structural member exhibits different mechanical properties in different directions. The adhesive layer provides strong coupling in the direction needed for sound generation while providing vibration isolation in the direction that would cause leakage, achieving directional control of vibration transmission.

Inventive Principle:
Principle #3Local quality

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 design achieves a sound pressure difference of -10dB to -15dB between the display and non-display sides, effectively minimizing sound leakage and protecting user privacy.

Implementation Method 1

piezoelectric sound-generating unit

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Data Source

PatentEP4037334B1Electronic device with display panel
Publication Date: 2026.02.25 BEIJING XIAOMI MOBILE SOFTWARE CO LTD
  • EP4037334B1 patent drawingFigure 1~2
  • EP4037334B1 patent drawingFigure 3~6

AI summary

The present disclosure relates to an electronic device (100). The electronic device (100) includes: a display panel assembly (1); a piezoelectric sound-generating unit (2) bonded to the display panel assembly (1) along a thickness direction of the electronic device; and a structural member (3) connected to the display panel assembly (1) or connected to the piezoelectric sound-generating unit (2) to close a cavity. The cavity is away from a side of the piezoelectric sound-generating unit (2) bonded to the display panel assembly (1).