Acoustic transducer systems with position sensing

Abstract

Acoustic transducer systems involving position sensing, and methods of operating and providing the acoustic transducer systems, are described herein. The described systems include a driver motor with a voice coil structure coupled to a diaphragm, the voice coil structure movable within an air gap in response to a magnetic flux; a position sensor to generate a position signal to represent a displacement of the diaphragm; and a system controller to modify an input signal based on the position signal and transmit the modified input signal to a voice coil so the voice coil can move in response to the modified input signal. The position sensor can generate the position signal based on optical sensing or strain measurements.

1 .- 37 . (canceled) 
     
     
         38 . A method of providing an acoustic transducer system, the method comprises:
 providing a driver motor, the driver motor comprising:
 an axial post; 
 a bottom plate extending away from the axial post; 
 a top plate having an interior surface facing the axial post, the top plate and the axial post defining an air gap therebetween; and 
 a magnetic element positioned between the bottom plate and the top plate, the magnetic element being spaced away from the axial post and the magnetic element operable to generate a magnetic flux; 
   mounting a moving assembly to the driver motor, the moving assembly comprising a diaphragm and a voice coil structure mounted to the diaphragm, the voice coil structure being movable at least partially within the air gap in response to the magnetic flux;   providing a position sensor for generating a position signal representing a displacement of the diaphragm relative to a reference position of the diaphragm, the position sensor comprising:
 a light transmitting component for transmitting an incident light towards the moving assembly; and 
 an optical detecting component for receiving a reflected optical signal corresponding to a reflection of the incident light from the moving assembly, the position signal being generated based on the reflected optical signal; and 
   providing a system controller in electronic communication with the driver motor and the position sensor, the system controller operable to modify an input audio signal from an input terminal based on the position signal received from the position sensor, and to transmit the modified input audio signal to a voice coil coupled to the voice coil structure.   
     
     
         39 . The method of  claim 38  comprises: defining a passage through one of the axial post and the magnetic element, the passage usable by the position sensor for at least one of transmitting the incident light towards one of the voice coil structure and the diaphragm and receiving the reflected optical signal. 
     
     
         40 . The method of  claim 38 , wherein providing the position sensor comprises: mounting the light transmitting component and the optical detecting component within the driver motor. 
     
     
         41 . The method of  claim 40  further comprises mounting the light transmitting component and the optical detecting component substantially across from an interior surface of the voice coil structure. 
     
     
         42 . The method of  claim 40  further comprises mounting the light transmitting component and the optical detecting component to a top surface of the axial post. 
     
     
         43 . (canceled) 
     
     
         44 . The method of  claim 39 , wherein providing the position sensor comprises:
 providing a first fiber optic cable as the light transmitting component for transmitting the incident light towards the voice coil structure and   providing a second fiber optic cable as the optical detecting component for receiving the reflected optical signal from the voice coil structure.   
     
     
         45 . (canceled) 
     
     
         46 . (canceled) 
     
     
         47 . (canceled) 
     
     
         48 . The method of  claim 38  comprises:
 providing a reflective target region at the voice coil structure, the reflective target region reflecting at least a portion of the incident light variably according to the displacement of the diaphragm. 
 
     
     
         49 . The method of  claim 48 , wherein providing the reflective target region at the voice coil structure comprises varying an area of the reflective target region according to a corresponding height of the voice coil structure. 
     
     
         50 . The method of  claim 48 , wherein providing the reflective target region at the voice coil structure comprises:
 defining a first reflective target region of the reflective target region for reflecting a first portion of the incident light variably according to the displacement of the diaphragm; and   defining a second reflective target region of the reflective target region for substantially reflecting a second portion of the incident light, the second portion of the incident light corresponding to a reference signal.   
     
     
         51 . (canceled) 
     
     
         52 . The method of  claim 39  further comprises: mounting the position sensor substantially within the passage defined within the one of the axial post and the magnetic element. 
     
     
         53 . The method of  claim 52 , wherein mounting the position sensor substantially within the passage comprises:
 mounting a first fiber optic cable as the light transmitting component for transmitting the incident light towards the diaphragm; and   mounting a second fiber optic cable as the optical detecting component for receiving the reflected optical signal from the diaphragm.   
     
     
         54 . The method of  claim 52  comprises: providing a reflective target region at an inner surface of the diaphragm for reflecting the incident light towards the optical detecting component. 
     
     
         55 . The method of  claim 38 , wherein providing the position sensor comprises providing the position sensor external to the driver motor, the light transmitting component transmitting the incident light towards an external surface of the diaphragm and the optical detecting component receiving the reflected optical signal from the external surface of the diaphragm. 
     
     
         56 . The method of  claim 55  further comprises:
 mounting a sensor support to the driver motor; and 
 mounting the position sensor to the sensor support. 
 
     
     
         57 . The method of  claim 55  further comprises:
 mounting a sensor support to the driver motor, the sensor support having an aperture; 
 providing a first fiber optic cable as the light transmitting component for transmitting the incident light towards the diaphragm; and 
 providing a second fiber optic cable as the optical detecting component for receiving the reflected optical signal from the diaphragm, 
 wherein each of the first fiber optic cable and the second fiber optic cable is provided via the aperture in the sensor support. 
 
     
     
         58 . (canceled) 
     
     
         59 . (canceled) 
     
     
         60 . The method of  claim 38 , wherein the reflected optical signal has an operational wavelength. 
     
     
         61 . (canceled) 
     
     
         62 . The method of  claim 60 , further comprising providing the reflective target region with a color to provide the reflected optical signal having the operational wavelength. 
     
     
         63 . The method of  claim 60 , further comprising modulating the incident light transmitted by the light transmitting component and wherein the optical detecting component is sensitive to the modulation. 
     
     
         64 . The method of  claim 60 , further comprising positioning one or more filters between the light transmitting component and the reflective target region. 
     
     
         65 . The method of  claim 60 , further comprising positioning one or more filters between the reflective target region and the optical detecting component. 
     
     
         66 .- 77 . (canceled)