Keyboard Resonance Noise Reduction Using Phase Inversion

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The reduction of keyboard resonance noise in personal computers is necessary due to the lighter and thinner design of PC devices, which causes noise interference affecting user experience.

Innovation Solution

A noise reduction method involving time-to-frequency conversion and phase inversion processing of audio signals to identify and cancel noise components, utilizing a noise reduction apparatus with integrated loudspeakers and microphones to enhance user experience.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of moving object

If the PC device is designed to be lighter and thinner, then the portability and form factor are improved, but keyboard resonance noise increases affecting user experience

Engineering Contradiction:
ImprovePC device weightVSAvoidkeyboard resonance noise
Core Design Contradiction:
Weight of moving objectVSObject-affected harmful factors

Solution Approach 1:

The system applies preliminary anti-action by generating an anti-phase audio signal before the keyboard resonance noise occurs. The noise reduction apparatus pre-processes the audio signal to create an inverted phase version that will cancel out the upcoming resonance noise when played through the loudspeaker, effectively neutralizing the harmful effect before it fully manifests.

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The system converts the harmful keyboard resonance noise into a beneficial cancellation effect. By detecting the resonance noise characteristics and generating an anti-phase signal, the system transforms the harmful resonance into a constructive interference pattern that results in noise cancellation, turning the problem into a solution.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

2Power

If high volume is required for the loudspeaker, then the audio output quality is improved, but keyboard resonance noise is generated

Engineering Contradiction:
Improveloudspeaker output powerVSAvoidkeyboard resonance noise
Core Design Contradiction:
PowerVSObject-generated harmful factors

Solution Approach 1:

The system implements feedback by continuously monitoring the audio signal and keyboard resonance characteristics, then using this information to dynamically adjust and generate the anti-phase cancellation signal. The noise reduction apparatus processes the audio signal through multiple stages including feedback loops that analyze resonance patterns and generate appropriate counter-signals to maintain high volume output while eliminating resonance noise.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The noise reduction apparatus acts as an intermediary between the audio source and the loudspeaker. It processes the audio signal through various filtering and phase inversion stages, introducing intermediate processing steps that cancel resonance noise before the signal reaches the loudspeaker, thereby allowing high power output without generating harmful resonance.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Object-affected harmful factors

If noise reduction processing is applied, then user experience is improved, but additional processing steps are required

Engineering Contradiction:
Improvenoise levelVSAvoidnoise reduction processing complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The system merges the noise reduction functionality with the existing audio processing pipeline. The noise reduction apparatus integrates phase inversion, filtering, and signal processing operations into a unified processing chain that works seamlessly with the existing loudspeaker and keyboard system, reducing overall complexity by combining multiple functions into integrated processing stages rather than separate independent systems.

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

Effectively reduces keyboard resonance noise by canceling noise signals, thereby improving user experience and audio quality in personal computers.

Implementation Method 1

performing time-to-frequency conversion processing on the first voice source to obtain a first frequency response line graph; performing time-to-frequency conversion processing on the second voice source to obtain a second frequency response line graph

Methodology Applied
Scientific EffectTime-to-frequency conversion:

Implementation Method 2

generating a noise reduction audio according to the to-be-processed audio, wherein the noise reduction audio and the to-be-processed audio have the same frequency and opposite phases

Methodology Applied
Scientific EffectPhase inversion:

Implementation Method 3

controlling the loudspeaker to play the noise reduction audio

Methodology Applied
Scientific EffectDestructive interference: Interference

Data Source

PatentEP4195199B1Noise reduction method and noise reduction apparatus
Publication Date: 2025.10.01 HONOR DEVICE CO LTD
  • EP4195199B1 patent drawingFigure 1
  • EP4195199B1 patent drawingFigure 2
  • EP4195199B1 patent drawingFigure 3

AI summary

A noise reduction method and a noise reduction apparatus are provided. The noise reduction method is applied to a keyboard of an integrated terminal device, and the noise reduction method includes: obtaining a first voice source and a second voice source, where the first voice source is a fidelity voice source, the second voice source is an audio signal that includes the first voice source and a noise signal, and the noise signal comes from noise generated by vibration of the keyboard, and/or the noise signal comes from noise of an environment in which the integrated terminal device is located; determining the noise signal based on the first voice source and the second voice source; and performing noise reduction processing on the second voice source based on the noise signal, to obtain a voice source that undergoes the noise reduction processing. Based on the technical solutions in this application, the noise signal generated by the integrated terminal device can be offset, so that noise reduction processing is implemented and user experience is improved.