Active Noise Cancellation Integrated Circuit Signal Stacking
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Solution Overview
Problem
Existing active noise cancellation technologies face issues with undesired compensation due to the superposition of audio waves from multiple microphones, leading to degraded audio playback.
Innovation Solution
The proposed solution involves an active noise cancellation headphone with an integrated circuit that stacks anti-noise signals and non-anti-noise signals using a first path and a second path, along with a decoupling unit to remove redundant components, thereby mitigating interference and enhancing noise cancellation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If multiple microphones are used to generate anti-noise signals from different positions, then noise cancellation coverage is improved, but audio wave superposition causes undesired compensation and degraded audio playback
Solution Approach 1:
The patent segments the signal processing into two distinct paths: a first path processes non-anti-noise signals (audio content) while a second path processes anti-noise signals (noise cancellation). This segmentation prevents the superposition of audio waves from multiple microphones from causing undesired compensation, as each path handles its specific signal type independently before controlled stacking at the output.
2Object-affected harmful factors
If anti-noise signals are stacked from multiple paths, then noise suppression effectiveness is improved, but interference between signals degrades audio playback integrity
Solution Approach 1:
The patent introduces a third decoupling unit as an intermediary component between the first and second paths. This decoupling unit specifically removes the component of the first signal (audio content) from the second path (anti-noise signal) based on the non-anti-noise signal. By using this intermediary to eliminate redundant components, the system achieves effective noise stacking while preventing interference that would degrade audio playback integrity.
3Reliability
If a decoupling unit is added to remove redundant signal components, then audio playback integrity is improved, but device complexity increases
Solution Approach 1:
The patent merges the decoupling function into the existing integrated circuit architecture by integrating the third decoupling unit with the first and second paths. Rather than adding a completely separate external device, the decoupling functionality is combined within the same circuit board, allowing the system to remove redundant signal components and maintain audio playback integrity while minimizing the increase in overall device complexity.
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
This approach effectively reduces interference between anti-noise signals, leading to improved noise suppression and maintaining the integrity of audio playback, thus addressing the deficiencies in existing technologies.
Implementation Method 1
an anti-noise signal is generated by a digital signal processing integrated circuit. By the destructive interference, the external noise would be canceled
Implementation Method 2
an end observation point receives the superposition of multiple audio waves, which leads to undesired compensation
Data Source
AI summary
The present invention relates to an active noise cancellation integrated circuit for stacking at least one anti-noise signal and at least one non-anti-noise signal, an associated method, and an active noise cancellation headphone using the same. The method is applicable to an audio playback device with at least one ANC filtering unit and at least one non-ANC filtering unit. The method includes: acquiring a non-anti-noise signal from a non-ANC filtering unit; generating a decoupled signal by processing the non-anti-noise signal with the transfer function of a physical channel and operations of an ANC filtering unit; performing a signal superposition, wherein an anti-noise signal from the 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.