| (19) |
 |
|
(11) |
EP 0 251 599 A3 |
| (12) |
EUROPEAN PATENT APPLICATION |
| (88) |
Date of publication A3: |
|
26.04.1989 Bulletin 1989/17 |
| (43) |
Date of publication A2: |
|
07.01.1988 Bulletin 1988/01 |
| (22) |
Date of filing: 19.06.1987 |
|
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| (84) |
Designated Contracting States: |
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BE CH DE ES FR GR IT LI NL SE |
| (30) |
Priority: |
19.06.1986 GB 8614940
|
| (71) |
Applicant: GEC-MARCONI LIMITED |
|
Stanmore,
Middlesex HA7 4LY (GB) |
|
| (72) |
Inventor: |
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- Flavell, David Graham
Dorset DT10 2NX (GB)
|
| (74) |
Representative: Cockayne, Gillian et al |
|
GEC Patent Department
Waterhouse Lane
Chelmsford, Essex CM1 2QX
Chelmsford, Essex CM1 2QX (GB) |
|
| |
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(57) An acoustic transducer l comprises a piezoelectric material 4 having a linear shape
and which is arranged in the form of a flat spiral within a body 2 of encapsulant
material. The piezoelectric material may be a polyvinylidine fluoride coaxial cable
and this thus can allow the construction of a high performance planar hydrophone at
relatively low cost.