Stereo Audio Compensation Using Autofocus Position Data

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Solution Overview

Problem

Most digital cameras have a single microphone, resulting in monaural audio during video playback, which fails to provide a spatial audio experience due to the lack of multiple sound capture points.

Innovation Solution

A recorder system that includes an optical assembly, audio system, and a compensation system to determine the position of a subject relative to the camera, allowing for the creation of a stereophonic sound track from a monaural audio source by adjusting sound based on the subject's position along one, two, or three axes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single microphone is used to capture sound, then the device complexity and cost are reduced, but the audio quality becomes monaural and lacks spatial representation

Engineering Contradiction:
Improvemicrophone configurationVSAvoidspatial audio information
Core Design Contradiction:
Device complexityVSLoss of information

Solution Approach 1:

The patent creates a virtual copy of the audio signal by generating a second audio signal that is a copy of the first audio signal captured by the single microphone. This virtual copy is then processed to simulate the effect of multiple microphones, allowing the system to reconstruct spatial audio information without physically adding multiple microphones to the device.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent transitions from one-dimensional monaural audio to two-dimensional or three-dimensional stereophonic audio by processing the single audio signal through spatial algorithms. The system adds spatial dimensionality to the audio representation by calculating position information and adjusting the audio signals accordingly, effectively creating a multi-dimensional audio experience from a single microphone input.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Loss of information

If multiple microphones are added to capture spatial audio, then the stereophonic sound quality is improved, but the device complexity and cost increase

Engineering Contradiction:
Improvespatial audio informationVSAvoidmicrophone configuration
Core Design Contradiction:
Loss of informationVSDevice complexity

Solution Approach 1:

Instead of physically adding multiple microphones, the patent creates virtual copies of the audio signal through processing. The system generates a second audio signal that replicates the characteristics of a multi-microphone setup by algorithmically processing the single microphone input, thereby achieving the same spatial audio效果 without the physical complexity of multiple microphones.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent replaces the mechanical system of multiple physical microphones with a digital signal processing system. Instead of using additional hardware components to capture spatial audio, the system uses computational algorithms to process the single microphone signal and synthesize the spatial audio experience, substituting mechanical complexity with digital processing.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Loss of information

If position information is used to adjust the sound track, then the spatial audio representation is improved, but the processing time and complexity increase

Engineering Contradiction:
Improvespatial audio informationVSAvoidprocessing time
Core Design Contradiction:
Loss of informationVSLoss of time

Solution Approach 1:

The patent performs preliminary processing by capturing position information of the sound source relative to the microphone at the time of audio recording. This pre-acquired position data is then used during the audio processing stage to adjust the sound track, allowing the system to leverage already-available spatial information rather than requiring real-time complex calculations during audio processing.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentUS8848927B2Recorder that creates stereophonic sound
Publication Date: 2014.09.30 NIKON CORP
  • US8848927B2 patent drawing
  • US8848927B2 patent drawing
  • US8848927B2 patent drawing

AI summary

A recorder (10) for recording a scene (12) includes an apparatus frame (218), an optical assembly (220), an image system (222), a position assembly (243), an audio system (224), and a compensation system (248). The image system (222) captures an image (252) of the scene (12). The position assembly (243) can be an autofocusing assembly (244) that focuses the optical assembly (220) on a subject (16) of the scene (12). The position assembly (243) generates position information relating to the position of the subject (16) relative to the recorder (10). The audio system (224) captures a captured sound from the scene (12). The compensation system (248) evaluates the position information and the captured sound from the scene (12) and provides an adjusted sound track in view of the position information.