Title:
PROJECTOR WITH TUNABLE RESONANCE FREQUENCY
Document Type and Number:
WIPO Patent Application WO2001052593
Kind Code:
A3
Abstract:
The invention provides a frequency tuneable projector (10, 100) comprising a cavity (106) at least partially surrounded by walls where at least one of the walls incorporates a transducing element (20a, 20d) and a tuning element (20b, 20c). The transducing element (20a, 20d) is operable to couple between electrical signals and corresponding mechanical vibrations of the walls. The tuning element (20b, 20c) is operable to provide an electrically modifiable stiffness for use in tuning a resonant frequency of the walls. The tuning element (20b, 20c) enables the projector to be tuned over a range of frequencies, thereby making it feasible for it to operate at resonance over the range of frequencies and thereby provide enhanced efficiency associated with operating at resonance. The walls are operable to vibrate in a bending mode or radial mode. The projector can be implemented as a vibrating cylindrical structure (400, 500) and can optionally incorporate end caps (430, 440), or be implemented as a circular structure (10, 100) incorporating one or more vibrating backing plates (16a, 16b) to which transducing and control elements (20a, 20b, 20c, 20d) are attached.
Inventors:
SMITH GRANT
Application Number:
PCT/GB2001/000054
Publication Date:
February 21, 2002
Filing Date:
January 08, 2001
Export Citation:
Assignee:
THOMSON MARCONI SONAR LTD (GB)
International Classes:
B06B1/06; B06B1/08; G10K11/04; (IPC1-7): G10K9/122; B06B1/06
Foreign References:
| US5315565A | 1994-05-24 | |||
| US3845333A | 1974-10-29 |
Other References:
PATENT ABSTRACTS OF JAPAN vol. 1998, no. 05 30 April 1998 (1998-04-30)
PATENT ABSTRACTS OF JAPAN vol. 015, no. 094 (E - 1041) 6 March 1991 (1991-03-06)
STEEL G A ET AL: "Tunable sonar transducer", ELECTRONICS LETTERS, 3 JULY 1986, UK, vol. 22, no. 14, pages 758 - 759, XP000996810, ISSN: 0013-5194
PATENT ABSTRACTS OF JAPAN vol. 1995, no. 02 31 March 1995 (1995-03-31)
PATENT ABSTRACTS OF JAPAN vol. 015, no. 094 (E - 1041) 6 March 1991 (1991-03-06)
STEEL G A ET AL: "Tunable sonar transducer", ELECTRONICS LETTERS, 3 JULY 1986, UK, vol. 22, no. 14, pages 758 - 759, XP000996810, ISSN: 0013-5194
PATENT ABSTRACTS OF JAPAN vol. 1995, no. 02 31 March 1995 (1995-03-31)
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