Paper structures for speaker transducers

• US 6,393,129 B1
• Filed: 08/16/1999
• Issued: 05/21/2002
• Est. Priority Date: 01/07/1998
• Status: Expired due to Fees

• Current Assignee: American Technology Incorporated (Emerson Electric Company)
• Original Assignee: American Technology Incorporated (Emerson Electric Company)
• Inventors: Croft, James J. III, Conrad, Terry J., Norris, Elwood G.
• Primary Examiner(s): Tran, Sinh
• Assistant Examiner(s): Dabney, P.
• Application Number:
  US09/374,813
• Time in Patent Office: 1,009 Days
• Field of Search: 381/113, 381/116, 381/174, 381/176, 381/399, 381/423, 381/426-428, 381/431, 381/FOR.163, 381/191, 367/170, 367/181, 181/167-170, 181/173-174
• US Class Current: 381/191
• CPC Class Codes: H04R 19/00 Electrostatic transducers
• CPC Class Codes: H04R 19/02 Loudspeakers H04R19/01 takes precedence
• CPC Class Codes: H04R 2217/03 Parametric transducers where sound is generated or captured by the acoustic demodulation of amplitude modulated ultrasonic waves
• CPC Class Codes: H04R 23/02 Transducers using more than one principle simultaneously

Abstract

An electroacoustic transducer which includes at least one stator member with an operating surface positioned adjacent to an emitter diaphragm. The stator member is comprised of at least one stiff sheet of paper having perforations for acoustic transparency. The stator also includes a means to develop electrical conductivity and to receive an applied voltage. An emitter diaphragm is suspended adjacent to and spaced a sufficient distance from the operating surface of the stator member to enable diaphragm oscillation in response to an applied signal voltage. This arrangement permits diaphragm movement within at least one emitter section without creating restrictive contact on the operating surface of the stator member. The diaphragm may be composed of paper with electrical conductivity sufficient to receive an acoustic signal voltage from a voltage source and to vibrate as an acoustic emitter with respect to forces applied at the stator member. Alternatively, the stator member may be of conventional construction, and combined with an emitter diaphragm constructed of a paper composition. Electrical contacts are also positioned on the stator member and the emitter diaphragm for coupling to appropriate voltage sources.

Claims

1. An electroacoustic transducer, including:

at least one stator member having an operating surface for positioning adjacent an emitter diaphragm, said at least one stator member being comprised of at least one stiff layer of paper having perforations for acoustic transparency and including means for developing electrical conductivity to receive an applied voltage;

an emitter diaphragm suspended adjacent to and spaced a sufficient distance from the operating surface of the stator member to enable diaphragm oscillation in response to an applied signal voltage to permit diaphragm movement within at least one emitter section without incurring interfering contact with the operating surface of the stator member;

electrical contacts positioned on the stator member for coupling to a voltage source; and

electrical biasing applied to the emitter diaphragm.

2. A transducer in accordance with claim 1, wherein the stator member comprises a sheet of paper having a thickness of less than approximately ⅛

of an inch.

3. A transducer in accordance with claim 1, wherein the stator member comprises a sheet of paper having a thickness of 0.02 inches.

4. A transducer in accordance with claim 1, wherein the stator member comprises a sheet of cardboard having a corrugated member and at least one planar side bonded to the corrugated member to provide sufficient stiffness to operate as a stator with respect to the emitter diaphragm, said planar side comprising the operating surface of the stator.

5. A transducer in accordance with claim 1, wherein the stator member comprises a sheet of cardboard having a corrugated member and at least one planar side bonded to the corrugated member to provide sufficient stiffness to operate as a stator with respect to the emitter diaphragm, said corrugated member comprising the operating surface of the stator.

6. A transducer as defined in claim 1, wherein the means for providing conductivity includes conductive doping material in the sheet of paper.

7. A transducer as defined in claim 1, wherein the means for providing conductivity includes conductive material disposed on a surface of the stator member, said conductive material being acoustically transparent to sound waves generated by the emitter diaphragm.

8. A transducer as defined in claim 7, wherein the conductive material comprises a layer of metal positioned on the operating surface of the stator member.

9. A transducer as defined in claim 1, wherein the stator member further is a corrugated stator formed from a sheet of stiff paper to provide sufficient stiffness to operate as a stator with respect to a corrugated emitter diaphragm, said corrugated stator comprising the operating surface of the stator and having a substantially similar curvature as the corrugated emitter diaphragm.

10. A transducer as defined in claim 9 wherein the corrugated stator is two corrugated stators on opposite sides of the corrugated diaphragm having a substantially similar curvature as the diaphragm.

11. A transducer as defined in claim 9 wherein the corrugated stator further comprises angled spacers to support the diaphragm and avoid distortion producing contact with the stators.

12. A transducer as defined in claim 1, wherein the stator member further comprises an insulation layer on the operating surface of the stator to reduce diaphragm impact and avoid distortion producing contact with the stators.

13. A transducer as defined in claim 12, wherein the layer of insulation is paper.

14. A transducer as defined in claim 1, wherein the stator member is a concave paper stator.

15. A transducer as defined in claim 1, wherein the stator member is a convex paper stator.

16. A transducer as defined in claim 1, wherein the stator member is formed in a shape selected from the group of shapes consisting of curved, circular, and semi-circular shapes.

17. A transducer as defined in claim 1 wherein the diaphragm comprises a sheet of paper and includes a layer of conductive material applied to at least one surface of the diaphragm to provide the electrical conductivity.

18. A transducer as defined in claim 17, wherein the layer of conductive material comprises a deposited layer of metal.

19. A transducer as defined in claim 17, wherein the layer of conductive material comprises conductive doping material contained in the sheet of paper.

20. A transducer as defined in claim 17, wherein the diaphragm comprises a second sheet of paper applied to the opposing side of the conductive material to provide a conductive sheet which is sandwiched between two sheets of paper.

21. A transducer as defined in claim 1, wherein the emitter diaphragm is configured with at least one increased stiffness orientation which provides a primary directional stiffness along the diaphragm and within the emitter section to provide support to maintain the emitter diaphragm in an operable condition in the absence of tension applied along the stiffness orientation.

22. A transducer as defined in claim 21, wherein the nonplanar cross-section of the diaphragm is configured with at least one added thickness to the diaphragm, running in the direction of increased thickness.

23. A transducer as in claim 21, wherein the nonplanar cross-section of the diaphragm is configured with varied compositions of reduced flexibility in strips on the diaphragm, running in the direction of increased stiffness.

24. A transducer as defined in claim 21, wherein the primary directional stiffness is developed by a non-planar configuration.

25. A transducer as defined in claim 24, wherein the non-planar configuration comprises corrugated channels formed into the emitter diaphragm which provide the primary directional stiffness.

26. A transducer as defined in claim 21, further including securing structure applied at the diaphragm with respect to the operating surface of the stator member to secure an intermediate cross-section of the diaphragm in fixed position with respect to the stator member to isolate at least two separate emitter sections of the diaphragm.

27. A transducer as defined in claim 26, wherein the conductive material comprises a layer of aluminum positioned on the operating surface of the stator member.

28. A transducer in accordance with claim 21, wherein the stator member comprises a sheet of paper having a thickness of less than approximately 0.125 inches.

29. A transducer in accordance with claim 21, wherein the stator member comprises a sheet of paper having a thickness of 0.02 inches.

30. A transducer in accordance with claim 21, wherein the stator member comprises a sheet of cardboard having a corrugated member and at least one planar side bonded to the corrugated member to provide sufficient stiffness to operate as a stator with respect to the emitter diaphragm, said planar side comprising the operating surface of the stator.

31. A transducer in accordance with claim 21, wherein the stator member comprises a sheet of cardboard having a corrugated member and at least one planar side bonded to the corrugated member to provide sufficient stiffness to operate as a stator with respect to the emitter diaphragm, said corrugated member comprising the operating surface of the stator.

32. A transducer as defined in claim 21, wherein the means for providing conductivity includes conductive doping material within the sheet of paper.

33. A transducer as defined in claim 21, wherein the means for providing conductivity includes conductive material disposed on a surface of the stator member, said conductive material being acoustically transparent to sound waves generated by the emitter diaphragm.

34. A transducer as defined in claim 1, wherein the corrugated channels of the emitter diaphragm conform in cross-sectional configuration with corresponding corrugated channels in the operating surface of the stator member, said emitter diaphragm being nested within the channels of the of the stator member.

35. A transducer as defined in claim 1, wherein surface areas of the respective at least two separate emitter sections of the diaphragm are different in size to provide different resonant frequencies.

36. A transducer as defined in claim 1, wherein the diaphragm has a random pattern of peaks and valleys.

37. A transducer as defined in claim 1, wherein the diaphragm is configured in a rectified sine wave configuration.

38. A transducer as defined in claim 1, wherein the diaphragm is configured in a sawtooth pattern of peaks and valleys.

39. A transducer as defined in claim 1, wherein the diaphragm is a plurality of diaphragms arranged adjacent to each other between the stators.

40. An electroacoustic transducer, including:

at least one stator member having an operating surface for positioning adjacent an emitter diaphragm, said at least one stator member being comprised of at least one stiff sheet of paper having perforations for acoustic transparency and including means for developing electrical conductivity to receive an applied voltage;

an emitter diaphragm suspended adjacent to and spaced a sufficient distance from the operating surface of the stator member to enable diaphragm oscillation in response to an applied signal voltage to permit diaphragm movement within at least one emitter section without incurring interfering contact with the operating surface of the stator member;

said diaphragm having a composition of paper having electrical conductivity sufficient to receive an acoustic signal voltage from a voltage source and to vibrate as an acoustic emitter with respect to forces applied at the stator member;

electrical contacts positioned on the stator member for coupling to a voltage source; and

electrical contacts positioned on the emitter diaphragm for coupling to a separate voltage source.