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Electrostatic transducer backplate having open ended grooves

  • US 4,311,881 A
  • Filed: 07/05/1979
  • Issued: 01/19/1982
  • Est. Priority Date: 07/05/1979
  • Status: Expired due to Term
First Claim
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1. An electrostatic transducer comprising a relatively inflexible support plate for a flexible diaphragm, said support plate having at least one major irregular surface of conductive material formed in a die forming operation employing a liquid lubricant, said major surface being defined by a series of projections spaced apart by intervening grooves, said grooves and said projections extending fully across said major surface to the peripheral edges thereof so as to provide open channels thereacross between each of said projections to eliminate entrapment of the liquid lubricant in each of said grooves during said die forming operation.

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