Transducer of the half-wave type with a piezoelectric polymer active element

Claim 1

A half-wave electro-acoustic transducer device, comprising: (a) a rigid frame having a recess and a rim, and a covering layer of an organic material having an inner face and an outer face, said inner face being fixed to said rim for capping said recess; (b) said device further comprising a foil of piezoelectric fluorinated polymer material having a radiating face and a rear face bonded along said outer face for forming with said covering layer a bilayer half-wave transducer structure; (c) said device still further comprising a first electrode deposit extending along said outer face and partially masked by said foil; (d) said radiating face carrying a second electrode deposit facing said first electrode deposit; (e) said inner face being acoustically coupled with a backing reflector medium having an acoustic impedance very substantially smaller than the acoustic impedance of said piezoelectric fluorinated polymer material; and (f) said organic material being selected for having an acoustic impedance value close to the acoustic impedance value of said piezoelectric fluorinated polymer material coupled with better adherence with said first electrode deposit.