Acoustic transducers

• US 9,226,078 B2
• Filed: 03/14/2014
• Issued: 12/29/2015
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: Emo Labs, Inc.
• Original Assignee: Emo Labs, Inc.
• Inventors: Hedges, Daniel, Bokaemper, Stefan, Jones, Terrence Keith
• Primary Examiner(s): Kuntz, Curtis
• Assistant Examiner(s): KAUFMAN, JOSHUA A
• Application Number:
  US14/212,043
• Publication Number:
  US 20140270327A1
• Time in Patent Office: 655 Days
• Field of Search: 381/152, 381/162, 381/163, 381/191, 381/423, 381/426, 381/431, 381/190, 381/395, 381/388, 381/333, 181/173, 181/167, 181/161, 181/154, 181/166
• US Class Current: 1/1
• CPC Class Codes: H04R 1/00 Details of transducers, loudspeakers or microphones
• CPC Class Codes: H04R 1/026 Supports for loudspeaker casings
• CPC Class Codes: H04R 1/22 for obtaining desired frequency characteristic only circuit for combining transducers having different responses H04R3/00; for hearing aids H04R25/407
• CPC Class Codes: H04R 1/24 Structural combinations of separate transducers or of two parts of the same transducer and responsive respectively to two or more frequency ranges
• CPC Class Codes: H04R 17/00 Piezoelectric transducers; Electrostrictive transducers piezoelectric or electrostrictive elements in general H10N30/00; details of piezoelectric or electrostrictive motors, generators or positioners H10N30/00
• CPC Class Codes: H04R 17/005 using a piezoelectric polymer
• CPC Class Codes: H04R 2217/01 Non-planar magnetostrictive, piezoelectric or electrostrictive benders
• CPC Class Codes: H04R 2307/021 Diaphragms comprising cellulose-like materials, e.g. wood, paper, linen
• CPC Class Codes: H04R 2307/023 Diaphragms comprising ceramic-like materials, e.g. pure ceramic, glass, boride, nitride, carbide, mica and carbon materials
• CPC Class Codes: H04R 2307/025 Diaphragms comprising polymeric materials
• CPC Class Codes: H04R 2307/027 Diaphragms comprising metallic materials
• CPC Class Codes: H04R 2400/11 Aspects regarding the frame of loudspeaker transducers
• CPC Class Codes: H04R 2440/05 Aspects relating to the positioning and way or means of mounting of exciters to resonant bending wave panels
• CPC Class Codes: H04R 5/00 Stereophonic arrangements stereophonic pick-ups H04R9/16, H04R11/12, H04R17/08, H04R19/10
• CPC Class Codes: H04R 7/045 using the distributed mode principle, i.e. whereby the acoustic radiation is emanated from uniformly distributed free bending wave vibration induced in a stiff panel and not from pistonic motion
• CPC Class Codes: H04R 7/12 Non-planar diaphragms or cones
• CPC Class Codes: H04R 7/16 Mounting or tensioning of diaphragms or cones
• CPC Class Codes: H04R 7/18 at the periphery
• CPC Class Codes: H04R 9/066 using the principle of inertia

Abstract

Acoustic transducers may, in certain aspects, include a curved diaphragm and an actuator coupled to the curved diaphragm to cause movement of the curved diaphragm. In certain embodiments, the curved diaphragm has at least one free edge. The left and right edges of the curved diaphragm may be associated with auxiliary supports. The acoustic transducer can be a multi-pole loudspeaker wherein a curved diaphragm radiates the sound energy in a modified dipole pattern. The curvature of the radiating surface of the transducer reduces sound cancellation from sound energy reflected by nearby surfaces.

Claims

1. An acoustic transducer comprising:

a curved diaphragm including a top portion, a left edge, a right edge, and a bottom portion wherein the top portion comprises a free edge, wherein the diaphragm is curved along the top and bottom portions and substantially straight on the left and right edges;

a support coupled to the diaphragm at the bottom portion;

a first auxiliary support associated with the diaphragm along the left edge;

a second auxiliary support associated with the diaphragm along the right edge; and

an actuator coupled to the bottom portion of the diaphragm,

wherein the acoustic transducer is configured such that the actuator, and not the first and second auxiliary supports, causes movement of the diaphragm.

2. The transducer according to claim 1, wherein the diaphragm is coupled substantially perpendicularly to the support.

3. The transducer according to claim 2, wherein the support comprises a curve that corresponds to the curve of the diaphragm.

4. The transducer according to claim 1, wherein the transducer comprises more than one free edge.

5. The transducer according to claim 1, wherein the diaphragm is composed of a material selected from the group consisting of plastic, metal, paper, carbon-fiber composite, fabric, foam, paper, glass, thin display materials and a combination thereof.

6. The transducer according to claim 1, wherein the actuator is a piezoelectric actuator.

7. The transducer according to claim 6, wherein the piezoelectric actuator is a bending-type piezoelectric actuator.

8. The transducer according to claim 7, wherein the bending-type actuator is a unimorph, bimorph, or multimorph actuator.

9. The transducer of claim 1, wherein the transducer employs mechanical amplification.

10. The transducer of claim 1, wherein movements between the actuator and the diaphragm employ mechanical amplification.

11. The transducer of claim 10, wherein a plurality of actuators act upon the diaphragm such that a plurality of audio signals is emitted separately from the diaphragm.

12. The transducer of claim 11, wherein the plurality of audio signals include a right and a left stereo signal.

13. The transducer of claim 11, wherein the plurality of audio signals includes a right, a left, and a center channel.

14. The transducer of claim 10 wherein:

a first actuator is operably coupled to a face of the curved diaphragm, near one end of the face;

a second actuator is operably coupled to the same face of the curved diaphragm, near an opposite end of the face;

and the first and second actuators are configured to move simultaneously in opposite directions so that the diaphragm oscillates between a greater and a lesser degree of curvature around a resting degree of curvature.

15. The transducer according to claim 1, wherein the diaphragm is composed of a non-piezo electric material.

16. An acoustic transducer comprising:

a curved diaphragm having a curved top portion, a curved bottom portion, a substantially straight left edge, and a substantially straight right edge;

a base coupled to the diaphragm at the curved bottom portion;

a plurality of auxiliary supports associated with the diaphragm along the left edge and along the right edge, respectively; and

an actuator coupled to the diaphragm, at the curved bottom portion,

wherein the acoustic transducer is configured such that the actuator, and not the first and second auxiliary supports, causes movement of the diaphragm.

17. The transducer according to claim 16, wherein the diaphragm comprises a free edge that is along the curved top portion of the diaphragm.

18. The transducer according to claim 16, wherein the diaphragm is coupled substantially perpendicularly to the base.

19. The transducer according to claim 16, wherein the diaphragm is composed of a material selected from the group consisting of plastic, metal, paper, carbon-fiber composite, fabric, foam, paper, glass or flexible display materials and a combination thereof.

20. The transducer according to claim 16, wherein the piezoelectric actuator is a bending-type piezoelectric actuator.

21. The transducer according to claim 20, wherein the bending-type actuator is a unimorph, bimorph, or multimorph actuator.

22. The transducer of claim 16, wherein the transducer employs mechanical amplification.

23. The transducer of claim 16, wherein movements between the actuator and the diaphragm employ mechanical amplification.

24. The transducer of claim 23, wherein a plurality of actuators act upon the diaphragm such that a plurality of audio signals is emitted separately from the diaphragm.

25. The transducer of claim 24, wherein the plurality of audio signals include a right and a left stereo signal.

26. The transducer of claim 24, wherein the plurality of audio signals includes a right, a left, and a center channel.

27. The transducer of claim 23 wherein:

a first actuator is operably coupled to a face of the curved diaphragm, near one end of the face;

a second actuator is operably coupled to the same face of the curved diaphragm, near an opposite end of the face; and

the first and second actuators are configured to move simultaneously in opposite directions so that the diaphragm oscillates between a greater and a lesser degree of curvature around a resting degree of curvature.

28. The transducer according to claim 16, wherein the diaphragm is composed of a non-piezo electric material.