On-Ear Transition Detection Using Speaker Current Monitoring
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Solution Overview
Problem
Existing on-ear transition detection systems in audio devices, such as headphones, face challenges in optimizing power performance, particularly in reducing power consumption while accurately detecting the transition between on-ear and off-ear states.
Innovation Solution
The implementation of a monitoring unit that tracks speaker current or voltage to generate a monitor signal, combined with an event detector to identify qualifying disturbances indicative of pressure changes, allowing for precise detection of transitions between on-ear and off-ear states.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If optical sensors or separate microphones are used to detect on-ear transitions, then detection accuracy is improved, but power consumption increases
Solution Approach 1:
The patent combines the speaker and microphone into a single integrated unit, where the speaker diaphragm serves dual purposes: driving sound output and detecting acoustic pressure changes for on-ear transition detection. This eliminates the need for separate detection components, reducing overall power consumption while maintaining detection accuracy through the integrated acoustic sensing capability.
2Speed
If the device remains in high-power state continuously, then detection responsiveness is improved, but battery life decreases
Solution Approach 1:
The patent implements periodic monitoring of acoustic pressure changes through the integrated microphone at low power levels, allowing the device to transition to high-power state only when a pressure change indicative of on-ear transition is detected. This periodic sensing approach maintains detection responsiveness while significantly extending battery life by minimizing the time spent in high-power state.
3Reliability
If separate detection components are added, then detection reliability is improved, but device complexity increases
Solution Approach 1:
The patent makes the speaker diaphragm a multi-functional component that simultaneously performs sound output and acoustic pressure detection for on-ear transition sensing. This universal application of the speaker component eliminates the need for additional dedicated sensors, reducing device complexity while maintaining detection reliability through the robust acoustic sensing capability inherent in the speaker structure.
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 enhances power management by accurately detecting ear presence or absence, enabling efficient switching between low-power and high-power states, thereby improving battery life in audio devices.
Implementation Method 1
a speaker and separate microphone provided in an in-ear headphone to determine an acoustic transfer function of the environment around the in-ear headphone in order to determine if the in-ear headphone is in the deployed state or in the non-deployed state
Data Source
AI summary
The disclosure relates in general to on-ear transition detection, and in particular to on-ear transition detection circuitry comprising: a monitoring unit operable to monitor a speaker current flowing through a speaker and/or a speaker voltage induced across the speaker, and to generate a monitor signal indicative of the speaker current and/or the speaker voltage; and an event detector operable to detect a qualifying disturbance in a sensor signal indicative of a qualifying pressure change incident on the speaker caused by the speaker transitioning from an on-ear state to an off-ear state or vice versa, wherein the sensor signal is, or is derived from, the monitor signal.