Projection Device Active Noise Cancellation for Cooling Fans

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Solution Overview

Problem

Projection apparatuses generate noise during operation, such as cooling fan noise and electronic component noise, which interfere with user experience.

Innovation Solution

A noise reduction method using a speaker to output a noise reduction signal based on a pre-configured target noise signal, determined by the cooling fan noise, and optionally using a microphone to collect and process noise signals for voice interactions, with noise feature information used to control the speaker output.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a cooling fan is used to cool electronic components, then the temperature control is improved, but noise is generated during operation

Engineering Contradiction:
Improvetemperature controlVSAvoidnoise
Core Design Contradiction:
TemperatureVSObject-generated harmful factors

Solution Approach 1:

The patent applies active noise control by using the speaker to emit anti-phase noise signals that cancel out the harmful cooling fan noise. The noise reduction signal generator creates a signal opposite in phase to the fan noise, and the speaker outputs this canceling signal, converting the harmful noise into a beneficial noise cancellation effect.

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

Solution Approach 2:

The patent introduces a noise reduction signal generator and speaker as intermediary components between the cooling fan noise source and the user. These intermediaries process the noise signal and generate a counter-signal that cancels the original noise, effectively mediating the harmful effect without changing the cooling fan operation.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-generated harmful factors

If noise reduction technology is added to cancel fan noise, then noise is reduced, but device complexity increases

Engineering Contradiction:
ImprovenoiseVSAvoiddevice complexity
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The patent makes the speaker serve multiple functions: it not only outputs audio content but also generates noise reduction signals to cancel fan noise. This multi-functionality reduces the need for separate dedicated noise cancellation hardware, thereby limiting the increase in device complexity while achieving noise reduction.

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

Solution Approach 2:

The system uses its own speaker component to provide noise cancellation functionality. The noise reduction signal generator processes signals from the speaker itself, and the speaker re-output the cleaned signal, allowing the system to self-service its noise problem using existing hardware rather than requiring external or additional specialized components.

Inventive Principle:
Principle #25Self-service

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 cancels out noise generated by the projection apparatus, improving sound quality and user experience without adding hardware.

Implementation Method 1

generating a noise reduction signal based on a pre-configured target noise signal... sending the noise reduction signal to the speaker for output... used to cancel out a noise generated by the projection apparatus

Methodology Applied
Scientific EffectDestructive interference: Interference

Data Source

PatentEP4607504A1Noise reduction method, projection device, and storage medium
Publication Date: 2025.08.27 SHENZHEN ROBOROCK INNOVATION TECH CO LTD
  • EP4607504A1 patent drawingFigure 1~2
  • EP4607504A1 patent drawingFigure 3
  • EP4607504A1 patent drawingFigure 4~5

AI summary

Disclosed are a noise reduction method, a projection device, and a storage medium. The noise reduction method can be applied to the projection device, and the projection device comprises: a loudspeaker and a heat dissipation fan. The method comprises: generating a noise reduction signal on the basis of a pre-configured target noise signal, wherein the target noise signal is determined on the basis of the noise generated when a heat dissipation fan works; and sending the noise reduction signal to a loudspeaker for output.