US Patent No. 9,100,759

LOUDSPEAKER DRIVER WITH SENSING COILS FOR SENSING THE POSITION AND VELOCITY OF A VOICE-COIL


Patent No. 9,100,759
Issue Date August 04, 2015
Title Loudspeaker Driver With Sensing Coils For Sensing The Position And Velocity Of A Voice-coil
Inventorship Johann Citerin, Cesson-Sevigne (FR)
Assignee Canon Kabushiki Kaisha, Tokyo (JP)

Claim of US Patent No. 9,100,759

1. A loudspeaker driver comprising:
at least one actuator connected to a vibrating support to impart excitation to the latter when caused to move,wherein the loudspeaker driver further comprises:
a plurality of sensing members arranged to move with the at least one actuator, each sensing member providing output sensing
data dependent on the velocity of said at least one actuator, and

means for determining the position of the at least one actuator based on at least one ratio X/Y of output sensing data or
of linear combinations of output sensing data provided from the plurality of sensing members, said at least one ratio being
independent of the velocity of the at least one actuator.