Acoustic device
An acoustic device has a suspended sheet of a thin flexible material having a rigid rod secured along one edge. An audio frequency actuator, which is preferably a magnetostrictive actuator, is acoustically coupled to an end face of the rod. The audiofrequency actuator is supplied with an audio signal from an audio source such as player device selected from the group which includes a recording tape player, a CD player, a DVD player, and a solid state memory device.
1. An acoustic device, comprising a sheet of a thin flexible material having a rigid elongate member secured thereto, an audio frequency actuator acoustically coupled to one end face of the elongate member, and means for supplying the audiofrequency actuator with an audio signal.
2. An acoustic device according to claim 1 , wherein the elongate member is secured to the sheet by means of adhesive.
3. An acoustic device according to claim 2 , wherein the adhesive is an inelastic adhesive.
4. An acoustic device according to claim 1 , wherein the elongate member is a metal rod.
5. An acoustic device according to claim 1 , wherein the elongate member is formed of a rigid polymeric material or a composite material.
6. An acoustic device according to claim 1 , wherein the audio frequency actuator is a giant magnetostrictive material (GMM) actuator.
7. An acoustic device according to claim 1 , wherein the actuator is bonded to the end of the elongate member.
8. An acoustic device according to claim 1 , wherein means are provided for suspending the sheet from at least one edge thereof.
9. An acoustic device according to claim 8 , wherein the sheet is suspended at two opposed ends thereof.
10. An acoustic device according to claim 9 , wherein the lowermost end of the sheet is suspended in such a manner as to form an end portion of the sheet into a curve.
11. An acoustic device according to claim 1 , wherein the elongate member is secured along an edge of the sheet.
12. An acoustic device according to claim 11 , wherein the elongate member is secured to the lowermost edge of the sheet.
13. An acoustic device according to claim 11 , wherein the sheet is formed into a roll at one edge thereof, and the elongate member is secured within the roll.
14. An acoustic device according to claim 1 , wherein the sheet is supported by the rigid elongate member.
15. An acoustic device according to claim 14 , wherein the sheet is sufficiently stiff to hold a curve therein.
16. An acoustic device according to claim 14 , wherein the sheet is provided with at least one stiffening support.
17. An acoustic device according to claim 1 , wherein the elongate member contains the audio frequency actuator and the means for supplying the actuator with an audio signal.
18. An acoustic device according to claim 17 , wherein the player device is selected from the group consisting of a recording tape player, a CD player, a DVD player, and a solid state memory device.
19. An acoustic device according to claim 18 , wherein the radio receiver is a broadcast radio receiver.
20. An acoustic device according to claim 18 , wherein the radio receiver is a receiver for a locally-radiated radio signal, for example providing a wireless connection from a local signal source.
21. An acoustic device according to claim 1 , wherein the means for supplying the audio signal comprises a player device for reproducing a recorded audiofrequency signal.
22. An acoustic device according to claim 1 , wherein the means for supplying the audio signal comprises a radio receiver or a network receiver.
23. An acoustic device according to claim 1 , wherein the thin flexible material is an extruded plastics sheet material or metal foil.
24. An acoustic device according to claim 1 , wherein the thin flexible material is a woven or non-woven textile material.
25. An acoustic device according to claim 1 , wherein the thin flexible material is paper or card.
26. An acoustic device according to claim 1 , further comprising a microphone directed to one side of the sheet and connected to a noise cancellation circuit for supplying the audiofrequency signal to the actuator, thereby causing the sheet to radiate an opposite signal to at least selected frequencies received by the microphone.
27. An acoustic device according to claim 26 , wherein the microphone is attached to a surface spaced from the sheet, the surface receiving the sound to be cancelled.
28. An acoustic device according to claim 27 , wherein the surface comprises a second flexible blind.
29. An acoustic device according to claim 27 , wherein the surface is a rigid sheet adjacent to the blind.
30. An acoustic device according to claim 29 , wherein the rigid sheet is glass.