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US 9,241,213 B2Granted
Acoustic transducer
AssigneeHarman Becker Gepkocsirendszer Gyarto Korlatolt Felelossegu Tarsasag
InventorsJohn B. French, David Russell
Life of this patent
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Abstract
This invention relates to acoustic transducers with stationary and moving coils, and methods for operating the acoustic transducers. Time varying signals are applied to the moving and stationary coils to control the movement of a diaphragm, which produces sound. The time varying signal applied to the moving coil corresponds to at least a processed version of an input audio signal and is updated based on, at least, a version of the time varying signal applied to the stationary coil. Some embodiments include updating the processed version of the input audio signal in response to a magnetic flux value corresponding to the time-varying signal applied to the stationary coil. Some embodiments include updating the time-varying signal applied to the moving coil in response to a feedback signal.
Claims26
A method of operating an acoustic transducer, the method comprising:
- receiving an input audio signal;
- generating a time-varying stationary coil signal in a stationary coil, wherein the time-varying stationary coil signal corresponds to the input audio signal, wherein the stationary coil induces a magnetic flux in a magnetic flux path;
- generating a time-varying moving coil signal in a moving coil, wherein:
- the moving coil is disposed within the magnetic flux path;
- the time-varying moving coil signal corresponds to both the time-varying stationary coil signal and a processed version of the input audio signal;
- and
- the time-varying moving coil is coupled to a moving diaphragm which moves in response to the time-varying moving coil signal;
- and
- generating the processed version of the input audio signal in response to a magnetic flux value corresponding to the time-varying stationary coil signal,
- wherein the magnetic flux value is determined by a method selected from the group consisting of:
- looking up the magnetic flux value in a lookup table;
- and
- determining the magnetic flux value using a polynomial.
10 more elements
An acoustic transducer comprising:
- an audio input terminal for receiving an input audio signal;
- a driver having:
- a moving diaphragm;
- a magnetic material having an air gap;
- a stationary coil for inducing magnetic flux in the magnetic material and the air gap;
- a moving coil coupled to the diaphragm wherein the moving coil is disposed at least partially within the air gap;
- and
- a control system adapted to:
- produce a time-varying stationary coil signal in the stationary coil, wherein the time-varying stationary coil signal corresponds to the input audio signal;
- produce a time-varying moving coil signal in the moving coil, wherein:
- the time-varying moving coil signal corresponds to both the time-varying stationary coil signal and a processed version of the input audio signal;
- and
- the time-varying moving coil is coupled to the moving diaphragm which moves in response to the time-varying moving coil signal;
- and
- generate the processed version of the input audio signal in response to a magnetic flux value corresponding to the time-varying stationary coil signal,
- wherein the magnetic flux value is determined by a method selected from the group consisting of:
- looking up the magnetic flux value in a lookup table;
- and
- determining the magnetic flux value using a polynomial.
16 more elements
A method of operating an acoustic transducer, the method comprising:
- receiving an input audio signal;
- generating a time-varying moving coil signal in a moving coil, wherein:
- the moving coil is disposed within a magnetic flux path;
- the time-varying moving coil signal corresponds to at least a processed version of the input audio signal;
- and
- the moving coil is coupled to a moving diaphragm which moves in response to the time-varying moving coil signal;
- generating a feedback signal for updating the time-varying moving coil signal;
- applying a time-varying stationary coil signal in a stationary coil, wherein the stationary coil induces a magnetic flux in the magnetic flux path, and wherein the time-varying stationary coil signal corresponds to the feedback signal;
- and
- updating the time-varying moving coil signal in response to the feedback signal,
- wherein generating the time-varying moving coil signal comprises:
- dividing the processed version of the input audio signal by the feedback signal.
9 more elements
An acoustic transducer comprising:
- an audio input terminal for receiving an input audio signal;
- a driver having:
- a moving diaphragm;
- a magnetic material having an air gap;
- a stationary coil for inducing magnetic flux in the magnetic material and the air gap;
- a moving coil coupled to the diaphragm wherein the moving coil is disposed at least partially within the air gap;
- a control system adapted to:
- generate a time-varying moving coil signal in the moving coil, wherein:
- the time-varying moving coil signal corresponds to at least a processed version of the input audio signal;
- and
- the moving coil is coupled to the moving diaphragm which moves in response to the time-varying moving coil signal;
- generate a feedback signal for updating the time-varying moving coil signal;
- apply a time-varying stationary coil signal in the stationary coil, wherein the time-varying stationary coil signal corresponds to the feedback signal;
- and
- update the time-varying moving coil signal in response to the feedback signal, and
- a permanent magnet for inducing magnetic flux in the air gap, wherein the control system is adapted to produce the time-varying stationary coil signal corresponding to both the input audio signal and the magnetic flux induced by the permanent magnet in the air gap.
13 more elements
An acoustic transducer comprising:
- an audio input terminal for receiving an input audio signal;
- a driver having:
- a moving diaphragm;
- a magnetic material having an air gap;
- a stationary coil for inducing magnetic flux in the magnetic material and the air gap;
- a moving coil coupled to the diaphragm wherein the moving coil is disposed at least partially within the air gap;
- and
- a control system adapted to:
- produce a time-varying stationary coil signal in the stationary coil,
- wherein the time-varying stationary coil signal corresponds to the input audio signal;
- produce a time-varying moving coil signal in the moving coil, wherein:
- the time-varying moving coil signal corresponds to both the time-varying stationary coil signal and a processed version of the input audio signal;
- and
- the time-varying moving coil is coupled to the moving diaphragm which moves in response to the time-varying moving coil signal;
- and
- generate the processed version of the input audio signal in response to a magnetic flux value corresponding to the time-varying stationary coil signal,
- wherein the magnetic flux value is determined by one of:
- a lookup table including the magnetic flux value;
- and
- a polynomial that provides the magnetic flux value.
17 more elements
Dependencies are inferred from the claim text.