US 2014/0153770 A1 · ACOUSTIC TRANSDUCER

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.

Claims29

Dependent claims

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.

6 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.

12 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:
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.

13 more elements

Dependencies are inferred from the claim text.

Acoustic transducer

Life of this patent

Acoustic transducer

Life of this patent

Abstract

Claims29