ATCO two new patents.
Aug. 22, 2000 / June 4, 1997
Application Number: US1997000868739
IPC Class: H04R 27/00;
Class: 381/083; 381/093; 381/077;
Field of Search: 381/94.1,77,82,79,93,83,66
Abstract: The present invention is embodied in a method and apparatus for eliminating audio feedback which includes an active microphone coupled to an amplifier which transmits signals received at the active microphone to a parametric speaker for broadcasting. The apparatus comprises at least one transducer for detecting at least one sonic frequency and generating an electrical signal representative of the at least one sonic frequency, a processor for receiving the electrical signal and generating a first ultrasonic frequency which has modulated thereon the at least one sonic frequency, a parametric demodulator for recovering the at least one sonic frequency from the first ultrasonic frequency, and a speaker for directly emitting the at least one sonic frequency
US1998000006689
IPC Class: H04R 25/00;
Class: 381/399; 381/406; 381/408; 381/162; 381/360; 367/140;
Field of Search: 381/162,163,164,360,368,176,177,395,421,429,406,408 367/140
Abstract: An ultrasonic emitter device having broad frequency range capacity with relatively large diaphragm displacement compared to typical electrostatic diaphragm movement. The device includes a core member able to establish a variable magnetic field adjacent the core member. A movable diaphragm is stretched along and displaced a short separation distance from the core member to allow an intended range of orthogonal displacement of the diaphragm within a strong portion of the magnetic field. At least one conductive ring disposed on the movable diaphragm within the influence of the variable magnetic field of the core member for enabling current flow through the ring for developing a second magnetic field which interacts with the first magnetic field to repel and relax the diaphragm at a desired frequency for development of a series of compression waves which may be adjusted to include an ultrasonic frequency range |
