EP 0973149 A3 20001227 - Ultrasonic transducers
Title (en)
Ultrasonic transducers
Title (de)
Ultraschallwandlern
Title (fr)
Transducteurs ultrasonores
Publication
Application
Priority
- US 11627198 A 19980716
- US 30020099 A 19990427
Abstract (en)
[origin: EP0973149A2] Sonic transducers utilize resonant cavities of varying depths to achieve wide operational bandwidth. The transducers (29) may include a conductive membrane (38) spaced apart from one or more backplate electrodes (32a,32b). In one approach, spacing is achieved using a dielectric spacer (34) having a series of depressions (36) arranged in a pattern, the depressions forming cavities each resonant at a predetermined frequency. In another approach, the conductive membrane (62) is piezoelectrically active, and the transducer is simultaneously driven in both piezoelectric and electrostatic modes. <IMAGE>
IPC 1-7
IPC 8 full level
B06B 1/02 (2006.01); B06B 1/06 (2006.01); H04R 17/00 (2006.01); H04R 17/10 (2006.01)
CPC (source: EP)
B06B 1/0292 (2013.01); B06B 1/0614 (2013.01); B06B 1/0688 (2013.01)
Citation (search report)
- [A] US 3816671 A 19740611 - FRAIM F, et al
- [A] GB 1234767 A 19710609 - DECCA LTD [GB]
- [A] PATENT ABSTRACTS OF JAPAN vol. 009, no. 027 (E - 294) 6 February 1985 (1985-02-06)
Designated contracting state (EPC)
AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE
DOCDB simple family (publication)
EP 0973149 A2 20000119; EP 0973149 A3 20001227; JP 2000050392 A 20000218; JP 4294798 B2 20090715
DOCDB simple family (application)
EP 99305633 A 19990715; JP 19638299 A 19990709