Miniature surface mounted directional microphone assembly

• US 6,560,344 B1
• Filed: 01/15/1999
• Issued: 05/06/2003
• Est. Priority Date: 10/30/1998
• Status: Expired due to Fees

• Current Assignee: Etymotic Research Incorporated
• Original Assignee: Etymotic Research Incorporated
• Inventors: Schulein, Robert B., Drambarean, Viorel, Julstrom, Stephen D.
• Primary Examiner(s): Nguyen, Duc
• Assistant Examiner(s): Ni, Suhan
• Application Number:
  US09/232,391
• Time in Patent Office: 1,572 Days
• Field of Search: 381/313, 381/322, 381/324, 381/328, 381/330, 381/356, 381/357, 381/358, 381/359, 381/360, 381/361
• US Class Current: 381/356
• CPC Class Codes: H04R 1/406 microphones
• CPC Class Codes: H04R 2499/13 Acoustic transducers and sound field adaptation in vehicles

Abstract

The present invention relates to a motor vehicle mounted directional microphone assembly for use in hands-free cellular telecommunications. The microphone assembly is comprised of a case and a removable directional microphone module. The case is adapted to mount and lock the module in a plurality of different orientations, thereby enabling the assembly to accommodate various mounting arrangements within the vehicle. The module is releasable, however, from its locked position to permit re-orientation of the microphone with respect to the case, if desired. The module is also completely removable from the case to permit mounting of the module within the vehicle in mounting arrangements independent of the case.

Claims

1. A directional microphone assembly comprising:

a removable directional microphone module;

a receiving unit adapted to releasably mount the removable directional microphone module in a plurality of different mounting positions, each of the plurality of different mounting positions being achieved at least in part by rotation of the removable directional microphone module about an axis and relative to the receiving unit, the removable directional microphone module generating a different polar directivity in each of the plurality of different mounting positions that corresponds to an angle of rotation of the removable directional microphone module about the axis; and

the removable directional microphone module and the receiving unit together comprising a locking arrangement that locks the removable directional microphone module in each of the plurality of different mounting positions, the locking arrangement preventing movement of the removable directional microphone module relative to the receiving unit when the removable directional microphone module is in each of the plurality of different mounting positions.

2. The directional microphone assembly of claim 1 wherein the removable directional microphone module comprises a directional microphone element having a front inlet port and a rear inlet port, a front sound inlet path acoustically coupled to the front inlet port, and a rear sound inlet path acoustically coupled to the rear inlet port.

3. The directional microphone assembly of claim 2 further comprising a windscreen located at least partially in the front and rear sound inlet paths.

4. The directional microphone assembly of claim 3 wherein the receiving unit further comprises a protruding portion and wherein the windscreen is compressed between an inner surface of the protruding portion and the directional microphone element.

5. The directional microphone assembly of claim 1 further comprising a windscreen located in the receiving unit.

6. The directional microphone assembly of claim 2 further comprising an extension tube acoustically coupled to the front inlet port.

7. The directional microphone assembly of claim 2 wherein the microphone module further comprises an acoustic resistor located in the rear inlet port.

8. The directional microphone assembly of claim 5 wherein the windscreen is comprised of at least one type of open cell acoustic foam.

9. The directional microphone assembly of claim 5 wherein the windscreen is comprised of at least two portions.

10. The directional microphone assembly of claim 9 wherein the windscreen is comprised of two portions, and wherein one portion is a ring and the other portion is a plug that fits into the ring.

11. The directional microphone assembly of claim 10 wherein the ring portion is comprised of a first type of open cell acoustic foam and the plug portion is comprised of a second type of acoustic foam.

12. The directional microphone assembly of claim 11 wherein the second type of open cell acoustic foam is more porous than the first type of acoustic foam.

13. The directional microphone assembly of claim 2 wherein the front and rear sound inlet paths have a controlled resonance in a desired sound pickup frequency range.

14. The directional microphone assembly of claim 2 wherein the removable directional microphone module further comprises a recess, and wherein the directional microphone element is mounted in the recess.

15. The directional microphone assembly of claim 14 further comprising a mechanical support located in the recess for mounting an extension tube.

16. The directional microphone assembly of claim 1 wherein the plurality of different mounting positions are discretely spaced.

17. The directional microphone assembly of claim 1 wherein the plurality of different mounting positions are substantially equally spaced from a reference axis.

18. The directional microphone assembly of claim 17 comprising four mounting positions.

19. The directional microphone assembly of claim 1 further comprising at least one mounting surface, and wherein the locking arrangement comprises a plurality of index notches located in the receiving unit and at least one index tab located in the removable directional microphone module, the at least one index tab engaging at least one of the plurality of index notches in mating relation when the removable directional microphone module is mounted on the at least one mounting surface.

20. The directional microphone assembly of claim 19 wherein the mounting surface is generally circular in shape and the index notches are located around the mounting surface.

21. The directional microphone assembly of claim 20 wherein an index notch is located at every 30°

angle from a reference axis.

22. The directional microphone assembly of claim 20 wherein the index notches are equally spaced from a reference axis.

23. A directional microphone assembly comprising:

a removable directional microphone module;

a receiving unit;

a mounting system that releasably mounts the removable directional microphone module at a plurality of different directional mounting positions within the receiving unit, each of the plurality of different directional mounting positions being achieved at least in part by rotation of the removable directional microphone module about an axis and relative to the receiving unit, the removable directional microphone module generating a different polar directivity in each of the plurality of different mounting positions that corresponds to an angle of rotation of the removable directional microphone module about the axis; and

the mounting system being configured to lock the removable directional microphone module in each of the plurality of different directional mounting positions, the mounting system preventing movement of the removable directional microphone module relative to the receiving unit when the removable directional microphone module is in each of the plurality of different directional mounting positions.

24. The directional microphone assembly of claim 23 wherein the removable directional microphone module comprises a directional microphone element having front and rear inlet ports, a front sound inlet path acoustically coupled to the front inlet port, and a rear sound inlet path acoustically coupled to the rear sound inlet port.

25. The directional microphone assembly of claim 24 further comprising a windscreen located at least partially in the front and rear sound inlet paths.

26. The directional microphone assembly of claim 25 wherein the receiving unit further comprises a protruding portion and wherein the windscreen is compressed between an inner surface of the protruding portion and the directional microphone element.

27. The directional microphone assembly of claim 23 further comprising a windscreen located in the receiving unit.

28. The directional microphone assembly of claim 24 further comprising an extension tube acoustically coupled to the front inlet port.

29. The directional microphone assembly of claim 24 wherein the microphone module further comprises an acoustic resistor located in the rear inlet port.

30. The directional microphone assembly of claim 27 wherein the windscreen is comprised of at least one type of an open cell acoustic foam material.

31. The directional microphone assembly of claim 27 wherein the windscreen is comprised of at least two portions.

32. The directional microphone assembly of claim 31 wherein the windscreen is comprised of two portions, and wherein one portion is a ring and the other portion is a plug that fits into the ring.

33. The directional microphone assembly of claim 32 wherein the ring portion is comprised of a first type of open cell acoustic foam and the plug portion is comprised of a second type of acoustic foam.

34. The directional microphone assembly of claim 33 wherein the second type of open cell acoustic foam is more porous than the first type of acoustic foam.

35. The directional microphone assembly of claim 24 wherein the front and rear sound inlet paths have a controlled resonance in a desired sound pickup frequency range.

36. The directional microphone assembly of claim 24 wherein the removable directional microphone module further comprises a recess, and wherein the directional microphone element is mounted in the recess.

37. The directional microphone assembly of claim 36 further comprising a mechanical support located in the recess for mounting an extension tube.

38. The directional microphone assembly of claim 23 wherein the plurality of different directional mounting positions are discretely spaced.

39. The directional microphone assembly of claim 23 wherein the plurality of different directional mounting positions are substantially equally spaced from a reference axis.

40. The directional microphone assembly of claim 39 comprising four mounting positions.

41. The directional microphone assembly of claim 23 wherein the mounting system comprises a plurality of index notches and at least one mounting surface, and wherein the removable directional microphone module has at least one index tab, the at least one index tab engaging at least one of the plurality of index notches in mating relation when the mounting system mounts and locks the removable module.

42. The directional microphone assembly of claim 41 wherein the mounting surface is generally circular in shape and the index notches are located around the mounting surface.

43. The directional microphone assembly of claim 42 wherein an index notch is located at every 30°

angle from a reference axis.

44. The directional microphone assembly of claim 42 wherein the index notches are equally spaced from a reference axis.

45. A directional microphone assembly comprising:

a removable directional microphone module;

a receiving unit;

a mounting system located in the receiving unit that releasably mounts and locks the removable directional microphone module at a plurality of different directional mounting positions within the receiving unit; and

a windscreen comprised of at least two portions, and having a ring portion and a plug portion, the plug portion fitting into the ring portion.

46. The directional microphone assembly of claim 45 wherein the ring portion is comprised of a first type of open cell acoustic foam and the plug portion is comprised of a second type of open cell acoustic foam.

47. The directional microphone assembly of claim 46 wherein the second type of open cell acoustic foam is more porous than the first type of open cell acoustic foam.