ANC IC Decoupling Unit for Stacking Anti-Noise Signals
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Solution Overview
Problem
Active noise cancellation systems often experience over-compensation due to the superposition of anti-phase audio waves generated by multiple microphones, leading to ineffective noise cancellation.
Innovation Solution
An active noise cancellation integrated circuit with multiple paths and a decoupling unit that removes redundant components from the error signal, allowing for improved noise cancellation by generating and stacking multiple anti-noise signals effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple microphones generate anti-phase audio waves for noise cancellation, then noise cancellation capability is improved, but over-compensation occurs leading to increased harmful factors
Solution Approach 1:
The patent segments the noise cancellation process into multiple independent paths (first path, second path, third path), each with its own ANC filtering unit processing signals from different microphones. This segmentation allows precise control of each anti-noise signal generation process, preventing the superposition and over-compensation issues that occur when multiple microphones work together without proper separation.
Solution Approach 2:
The patent introduces a decoupling unit as an intermediary component that processes the error signal by removing components generated by other paths before the signal enters the second ANC filtering unit. This intermediary action prevents the harmful superposition of anti-phase waves by ensuring each path only compensates for actual external noise, not the artifacts created by other paths.
2Reliability
If multiple ANC filtering units process signals from different microphones, then noise cancellation coverage is improved, but signal interference occurs reducing measurement precision
Solution Approach 1:
The system is divided into multiple independent processing paths, each with dedicated ANC filtering units (first ANC filtering unit, second ANC filtering unit, third ANC filtering unit) that process signals from different microphones separately. This segmentation maintains signal integrity within each path while achieving comprehensive noise cancellation coverage through the combination of all paths.
Solution Approach 2:
The decoupling unit serves as an intermediary that cleans the error signal by removing components generated by other paths before they interfere with the second ANC filtering unit's processing. This intermediary action preserves measurement precision by ensuring each filtering unit works with纯净 error signals that accurately represent external noise.
3Reliability
If anti-noise signals are stacked from multiple paths, then noise elimination effectiveness is improved, but redundant components cause over-compensation
Solution Approach 1:
The decoupling unit extracts and removes redundant components from the error signal that are generated by other paths. By taking out these redundant signal components before they enter the second ANC filtering unit, the system avoids over-compensation and the associated energy waste while maintaining effective noise elimination through the essential anti-noise signals.
Solution Approach 2:
The patent implements a balanced approach where multiple paths generate anti-noise signals (partial action for each path) but the decoupling unit prevents excessive action by removing redundant components. This ensures the total anti-noise signal is sufficient for noise cancellation without exceeding the required compensation level, thereby avoiding energy waste from over-compensation.
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 enhances noise cancellation by ensuring the output noise cancellation signal aligns better with the received noise, effectively reducing interference and improving noise suppression.
Implementation Method 1
an anti-noise signal is generated by a digital signal processing integrated circuit. Regarding the feedback ANC, a noise receiving microphone is disposed inside headphones for receiving audio in ear canals, and an anti-noise signal is generated by feedback the audio to the digital signal processing integrated circuit. In addition, the hybrid ANC uses two or more noise receiving microphones to pick up noises, and generates multiple anti-noise signals through different digital signal processing integrated circuits, respectively, and stacks the anti-noise signals to eliminate noises.
Implementation Method 2
Since anti-phase audio waves are generated by signals from multiple microphones disposed on different positions and by different signal process, an end observation point receives the superposition of multiple anti-phase audio waves
Data Source
AI summary
The present invention relates to an active noise cancellation integrated circuit for stacking multiple anti-noise signals, an associated method, and an active noise cancellation headphone using the same. The method is applicable to an audio playback device with multiple ANC filtering units. The method includes: acquiring an anti-noise signal from an ANC filtering unit; generating a decoupled signal by processing the anti-noise signal with the transfer function of a physical channel and operations of other ANC filtering units; performing a signal superposition, wherein an anti-noise signal from another ANC filtering unit is superposed with the decoupled signal; and performing an audio playback based on the superposed signal and an audio signal such that noise is eliminated.