Thomas, Kayden, Horstemeyer & Risley
Electrostatic transducer and method for manufacturing same
 Electrostatic transducers (10, 100) for generating and/or sensing percussion waves have an internal rigid unitary element comprising an insulating sleeve (17, 117), an electrode backplate (21, 121) situated within the sleeve (17, 117), and a dielectric layer (22, 122) which secures the electrode backplate (21, 121) within the sleeve (17, 117). The dielectric layer (22, 122) is a generally continuous layer and has support fingers (24, 124) protruding outwardly away from the electrode backplate (21, 121) for supporting an electrode diaphragm (26, 126), preferably a durable metal foil. The electrode diaphragm (26, 126) may be hermetically sealed to a housing (111), which encloses the unitary element so that the transducers (10, 100) are better suited for harsh, extreme high/low temperature, and/or extreme high/low pressure environments. Furthermore, the interior region (32, 132) of the transducer (10, 100) can be evacuated via a throughway (31, 131) so that the transducer power can be increased. 
Gas Research Institute
H B
H04R B06B
inventional inventional
James A. Anthony R. H.
Hill Goodwin