Electroacoustic transducer with diaphragm securing structure and method

• US 6,535,612 B1
• Filed: 08/16/1999
• Issued: 03/18/2003
• Est. Priority Date: 12/07/1998
• Status: Expired due to Fees

• Current Assignee: American Technology Incorporated (Emerson Electric Company)
• Original Assignee: American Technology Incorporated (Emerson Electric Company)
• Inventors: Conrad, Terry J., Croft, James J. III
• Primary Examiner(s): Kuntz, Curtis
• Assistant Examiner(s): Harvey, Dionne
• Application Number:
  US09/375,145
• Time in Patent Office: 1,310 Days
• Field of Search: 381/184, 381/395, 381/191, 381/398, 381/399, 381/402, 381/423
• US Class Current: 381/191
• CPC Class Codes: H04R 19/02 Loudspeakers H04R19/01 takes precedence
• CPC Class Codes: H04R 7/14 corrugated, pleated or ribbed

Abstract

An electroacoustic transducer which has at least one stator member with an operating surface and a suspended emitter diaphragm spaced from the operating surface of the stator member to enable the diaphragm to oscillate in response to an applied signal voltage. The diaphragm has increased stiffness in a direction along the diaphragm and within the emitter section to enable the emitter diaphragm to oscillate without applying tension in the direction of stiffness. A clamp member secures the diaphragm to maintain the diaphragm in a fixed position relative to the stator to minimize distortion. The clamp member is positioned to define at least two isolated emitter sections for enhancing the frequency response of the transducer.

A method is also provided for generating audio output from an electroacoustic transducer. A stator member with an operating surface is positioned adjacent to an emitter diaphragm, which is suspended and spaced a sufficient distance from the operating surface of the stator member to enable diaphragm oscillation in an emitter section of the diaphragm in response to an applied signal voltage. The diaphragm is configured with increased stiffness longitudinally along the diaphragm and within the emitter section to enable the emitter diaphragm to oscillate without applying tension in the direction of stiffness. A clamp is positioned between the diaphragm and the operating surface of the stator member to maintain the diaphragm in a fixed position relative to the stator. Emitter sections on the diaphragm are established by the clamp to provide complementary resonant frequencies, to enhance the frequency response of the transducer.

Claims

1. An electroacoustic transducer, including:

at least one stator member having an operating surface for positioning adjacent an emitter diaphragm;

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 contacting the operating surface of the stator member;

said diaphragm being configured with alternating peaks and valleys extending along a longitudinal dimension of the diaphragm, including an increased stiffness orientation which provides greater directional stiffness along the longitudinal dimension, wherein the alternating

a securing structure applied in transverse orientation with respect to the stiffness orientation at the diaphragm with respect to the operating surface of the stator member to secure the diaphragm in a fixed position.

2. The electroacoustic transducer of claim 1, wherein the securing structure is a single elongated member having an outer surface in contact with the stator member and an inner surface secured to the diaphragm.

3. The electroacoustic transducer of claim 2, wherein the inner surface of the elongated member is secured to the diaphragm by adhesive.

4. The electroacoustic transducer of claim 2, wherein the inner surface of the elongated member conforms to the shape of the diaphragm.

5. The electroacoustic transducer of claim 1, wherein the securing structure is a pair of elongated members on opposite sides of the diaphragm, each elongated member having an outer surface in contact with the stator member and an inner surface secured to the diaphragm.

6. The electroacoustic transducer of claim 5, wherein the inner surface of at least one of the elongated members is secured to the diaphragm by adhesive.

7. The electroacoustic transducer of claim 5, wherein the inner surface of at least one of the pair of elongated members conforms to the shape of the diaphragm.

8. The electroacoustic transducer of claim 5, wherein the diaphragm is a non-planar structure and the inner surfaces of the pair of elongated members are substantially planar and are disposed substantially adjacent to each other with the diaphragm in between, thereby deforming the non-planar structure of the diaphragm at the point of contact of the elongated members.

9. The electroacoustic transducer of claim 1, wherein the increased stiffness orientation of the diaphragm is provided by the diaphragm having a substantially non-planar cross-section along the diaphragm in the direction of increased stiffness of the diaphragm, thereby providing support to enable the diaphragm to oscillate in the absence of tension in the direction of stiffness.

10. The electroacoustic transducer of claim 9, wherein nonplanar cross-section of the diaphragm is configured with multiple peaks and valleys along the cross-section.

11. The electroacoustic transducer of claim 9, wherein the nonplanar cross-section of the diaphragm is configured to approximate a sine wave.

12. The electroacoustic transducer of claim 9, wherein the nonplanar cross-section of the diaphragm is configured to approximate a rectified sine wave.

13. The electroacoustic transducer of claim 9, 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 stiffness.

14. The electroacoustic transducer of claim 9, wherein the nonplanar cross-section of the diaphragm is configured with a varied composition of reduced flexibility in strips on the diaphragm, running in the direction of increased stiffness.

15. The electroacoustic transducer of claim 1, wherein the securing structure comprises at least one elongated clamp member extending across the diaphragm at an intermediate position with respect to the direction of increased stiffness of the diaphragm, to form at least two of said emitter sections.

16. The electroacoustic transducer of claim 15, wherein the elongated clamp member extends across the diaphragm to divide the diaphragm into at least two of said emitter sections of different sizes.

17. The electroacoustic transducer of claim 15, wherein at least one elongated clamp member extends substantially normal to the direction of increased stiffness of the diaphragm.

18. The electroacoustic transducer of claim 15, wherein at least one elongated clamp member extends at an acute angle to the direction of increased stiffness of the diaphragm to form at least one emitter section having multiple resonant frequencies.

19. The electroacoustic transducer of claim 1, wherein the at least one stator member comprises opposing stators disposed substantially parallel to the diaphragm on opposite sides thereof.

20. The electroacoustic transducer of claim 19, wherein the opposing stators and diaphragm include means for the signal voltage to be applied across the opposing stators and for a voltage bias to be applied to the diaphragm to enable the diaphragm to acoustically oscillate.

21. The electroacoustic transducer of claim 20, wherein the opposing stators and diaphragm include means for the signal voltage to be applied electrostatically to the opposing stators.

22. The electroacoustic transducer of claim 20, wherein the opposing stators and diaphragm include means for the signal voltage to be applied magnetically to the opposing stators.

23. The electroacoustic transducer of claim 1, wherein the diaphragm operably oscillates in the absence of tension applied along the direction of stiffness.

24. The electroacoustic transducer of claim 1, wherein the diaphragm operably oscillates with tension applied along the direction of stiffness.

25. The electroacoustic transducer of claim 1 further comprising a plurality of equally spaced clamps arranged to create diaphragm regions each having an equivalent resonant frequency to boost the sound output at that frequency.

26. The electroacoustic transducer of claim 1 wherein the securing structure is nonplanar.

27. An electroacoustic transducer, including:

opposing stators substantially parallel to each other, each stator having an operating surface facing the operating surface of the opposing stator;

an emitter diaphragm suspended between the opposing stators and spaced a sufficient distance from the operating surfaces of the stators to enable diaphragm oscillation in an emitter section of the diaphragm in response to an applied signal voltage without contacting the operating surfaces of the stators.

the diaphragm being configured with alternating peaks and valleys extending along a longitudinal dimension of the diaphragm, including an increased stiffness orientation which provides greater directional stiffness along the longitudinal dimension, wherein the alternating peaks and valleys produce acoustic output; and

a securing structure positioned between the diaphragm and the operating surface of each stator to secure the diaphragm in a fixed position relative to the stator.

28. The electroacoustic transducer of claim 27, wherein the diaphragm is configured with a non-planar cross-section to provide directional stiffness along the diaphragm.

29. The electroacoustic transducer of claim 27, wherein the securing structure comprises a clamp member clamping the diaphragm and extending across the direction of increased stiffness of the diaphragm.

30. The electroacoustic transducer of claim 27, wherein the clamp member extends at an acute angle to the direction of increased stiffness of the diaphragm to form at least one emitter section having multiple resonant frequencies.

31. A method for generating audio output from an electroacoustic transducer, comprising the steps of:

positioning at least one stator member having an operating surface adjacent an emitter diaphragm;

suspending an emitter diaphragm adjacent to and spaced a sufficient distance from the operating surface of the stator member to enable diaphragm oscillation in an emitter section of the diaphragm in response to an applied signal voltage without contacting the operating surface of the stator member;

configuring the diaphragm with alternating peaks and valleys, including at least one increased stiffness orientation which provides greater directional stiffness along a longitudinal direction of the diaphragm and within the emitter section to enable the emitter diaphragm to operably oscillate in the absence of tension applied along the stiffness orientation; and

positioning a securing structure between the diaphragm and the operating surface of the stator member to secure the diaphragm in a fixed position relative to the stator.

32. The method for generating audio output from an electroacoustic transducer of claim 31, wherein the step of positioning the securing structure comprises positioning an elongated member having an outer surface in contact with the stator member and an inner surface secured to the diaphragm.

33. The method for generating audio output from an electroacoustic transducer of claim 31 wherein the positioning step comprises positioning an elongated member having an inner surface conforming to the shape of the diaphragm.

34. The method for generating audio output from an electroacoustic transducer of claim 31 wherein the positioning step comprises positioning a pair of elongated members on opposite sides of the diaphragm, each elongated member having an outer surface in contact with the stator member and an inner surface secured to the diaphragm.

35. The method for generating audio output from an electroacoustic transducer of claim 34, and further configuring the inner surface of at least one of the pair of elongated members to conform to the shape of the diaphragm.

36. The method for generating audio output from an electroacoustic transducer of claim 34, and further configuring the inner surfaces of the pair of elongated members to be substantially planar and disposing the pair of elongated members substantially adjacent to each other with a non-planar diaphragm in between, thereby deforming the non-planar diaphragm at a point of contact with the pair of elongated members.

37. The method for generating audio output from an electroacoustic transducer of claim 31, wherein the diaphragm is configured with a substantially non-planar cross-section along the diaphragm in the direction of increased stiffness of the diaphragm, thereby providing support to enable the diaphragm to oscillate in the absence of tension in the direction of stiffness.

38. The method for generating audio output from an electroacoustic transducer of claim 37, wherein the nonplanar cross-section of the diaphragm is configured with multiple peaks and valleys along the cross-section.

39. The method for generating audio output from an electroacoustic transducer of claim 31, 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 stiffness.

40. The method for generating audio output from an electroacoustic transducer of claim 31, wherein the nonplanar cross-section of the diaphragm is configured with a varied composition of reduced flexibility in strips, on the diaphragm, running in the direction of increased stiffness.

41. The method for generating audio output from an electroacoustic transducer of claim 31, wherein the step of positioning the securing structure comprises positioning at least one elongated clamp member to extend across the diaphragm at an intermediate position with respect to the direction of increased stiffness of the diaphragm, to form at least two said emitter sections.

42. The method for generating audio output from an electroacoustic transducer of claim 41, wherein the positioning step comprises positioning the elongated clamp member to extend perpendicular across the direction of increased stiffness of the diaphragm to divide the diaphragm into at least two said emitter sections of different sizes.

43. The method for generating audio output from an electroacoustic transducer of claim 41, wherein the positioning step comprises positioning at least one elongated clamp member to extend substantially transverse to the direction of increased stiffness of the diaphragm.

44. The method for generating audio output from an electroacoustic transducer of claim 41, wherein the positioning step comprises positioning at least one elongated clamp member to extend at an acute angle to the direction of increased stiffness of the diaphragm to form at least one emitter section having multiple resonant frequencies.

45. A method for generating audio output from an electroacoustic transducer, comprising the steps of:

disposing opposing stators substantially parallel to each other, each stator having an operating surface facing the operating surface of the opposing stator;

suspending an emitter diaphragm between the opposing stators spaced a sufficient distance from the operating surfaces of the stators to enable diaphragm oscillation in an emitter section of the diaphragm in response to an applied signal voltage without contacting the operating surfaces of the stators,

configuring the diaphragm with alternating peaks and valleys extending along a longitudinal dimension of the diaphragm, including an increased stiffness orientation which provides greater directional stiffness along the longitudinal dimension, wherein the alternating peaks and valleys produce acoustic output; and

positioning a securing structure between the diaphragm and the operating surface of the stators to secure the diaphragm in a fixed position relative to the stators. the diaphragm with an orientation which provides a primary directional stiffness along the diaphragm and within the emitter section to enable the emitter diaphragm to operably oscillate in the absence of tension applied along the stiffness orientation; and

positioning a securing structure be(teen the diaphragm and the operating surface of the stators to secure the diaphragm in a fixed position relative to the stators.

46. The method for generating audio output from an electroacoustic transducer of claim 45, and further comprising configuring the diaphragm with a non-planar cross-section to provide directional stiffness along the diaphragm.

47. The method for generating audio output from an electroacoustic transducer of claim 46, wherein the securing step comprises clamping the diaphragm with a clamp member extending across the direction of increased stiffness of the diaphragm.

48. The method for generating audio output from an electroacoustic transducer of claim 47, wherein the clamping step comprises positioning at least one clamp member to extend at an acute angle to the direction of increased stiffness of the diaphragm to form at least one emitter section having multiple resonant frequencies.

49. An electrostatic transducer, comprising:

at least one corrugated stator member having an operating surface for positioning adjacent an emitter diaphragm;

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 and to permit diaphragm movement within at least one emitter section without contacting the operating surface of the stator member; and

said diaphragm being configured with at least one increased stiffness orientation which provides greater directional stiffness along a longitudinal dimension of the diaphragm and within the emitter section to enable the emitter diaphragm to operably oscillate at a desired resonant frequency.

50. The electrostatic transducer as in claim 49 further comprising at least one securing structure applied in transverse orientation with respect to the stiffness orientation at the diaphragm and the operating surface of the corrugated stator member to secure the diaphragm in a fixed position.

51. The electrostatic transducer as in claim 50 wherein the diaphragm is corrugated.

52. The electrostatic transducer as in claim 51 wherein the emitter diaphragm is substantially equidistantly spaced from directly adjacent points on the at least one corrugated stator member and secured in position by the securing structure.

53. The electrostatic transducer as in claim 51 further comprising at least two securing structures for securing the diaphragm, equidistantly from directly adjacent points on the at least one corrugated stator member between two securing structures.

54. The electrostatic transducer as in claim 51 further comprising at least three securing structures wherein a first substantially equidistant space exists from points on the diaphragm to directly adjacent points on the at least one corrugated stator member between a first and second securing structures, and a second substantially equidistant space exists from points on the diaphragm to directly adjacent points on the at least one corrugated stator member between a second and third securing structures.

55. The electrostatic transducer as in claim 50 wherein the at least one securing structure extends at an acute angle to the direction of increased stiffness of the diaphragm to form at least one emitter section having multiple resonant frequencies.

56. An electrostatic transducer, comprising:

opposing corrugated stators substantially parallel to each other, each stator having an operating surface facing the operating surface of an opposing stator;

an emitter diaphragm suspended between the opposing stators and spaced a sufficient distance from the operating surfaces of the stators to enable diaphragm oscillation in an emitter section of the diaphragm in response to an applied signal voltage without contacting the operating surfaces of the stators; and

wherein the diaphragm is configured with an orientation which provides greater directional stiffness along a longitudinal direction of the diaphragm and within the emitter section to enable the emitter diaphragm to operably oscillate in the absence of tension applied along the stiffness orientation.

57. The electrostatic transducer as in claim 56 further comprising at least one securing structure positioned between the diaphragm and the operating surface of each corrugated stator to secure the diaphragm in a fixed position relative to the corrugated stators.

58. The electrostatic transducer as in claim 57 wherein the securing structure is corrugated.

59. The electrostatic transducer as in claim 58 wherein the emitter diaphragm is equidistantly spaced from directly adjacent points on the opposing corrugated stators and secured in position by the securing structure.

60. The electrostatic transducer as in claim 56 wherein the diaphragm is closely positioned to the opposing corrugated stators to increase the effects of electrostatic field effects on the diaphragm.

61. The electrostatic transducer as in claim 56 further comprising openings in the opposing corrugated stators to provide acoustic transparency.

62. The electrostatic transducer as in claim 56 wherein the diaphragm is corrugated.

63. The electrostatic transducer as in claim 56 wherein the corrugated stators form a substantially curved shape.

64. The electrostatic transducer as in claim 56 wherein the corrugated stators form a substantially hemispherical shape.

65. The electrostatic transducer as in claim 56 wherein the corrugated stators form a substantially spherical shape.

66. The electrostatic transducer as in claim 56 wherein the corrugated stators form a substantially cylindrical shape.

67. The electrostatic transducer as in claim 58 further comprising at least two securing structures for securing the diaphragm equidistantly from directly adjacent points on the at least one corrugated stator member between two securing structures.

68. The electrostatic transducer as in claim 58 further comprising at least three securing structures wherein a first substantially equidistant space exists from points on the diaphragm to directly adjacent points on the at least one corrugated stator member between a first and second securing structures, and a second substantially equidistant space exists from points on the diaphragm to directly adjacent points on the at least one corrugated stator member between a second and third securing structures.

69. The electrostatic transducer as in claim 57 wherein the at least one securing structure extends at an acute angle to the direction of increased stiffness of the diaphragm to form at least one emitter section having multiple resonant frequencies.

70. An electroacoustic transducer, including:

at least one stator member having an operating surface for positioning adjacent an emitter diaphragm;

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 contacting the operating surface of the stator member;

said diaphragm being configured with alternating peaks and valleys extending along a longitudinal dimension of the diaphragm, including an increased stiffness orientation which provides greater directional stiffness along the longitudinal direction, wherein the alternating peaks and valleys produce acoustic output; and

a securing structure, applied in transverse orientation with respect to the stiffness orientation at the diaphragm, having a diaphragm contacting portion which has a substantially non-planar configuration that corresponds to the alternating peaks and valleys of the diaphragm, to secure the diaphragm in a fixed position.