Optical particle detectors

• US 20080018485A1
• Filed: 07/18/2006
• Published: 01/24/2008
• Est. Priority Date: 07/18/2006
• Status: Active Grant

• Current Assignee: Gentex Corporation
• Original Assignee: Gentex Corporation
• Inventors: Stirling, Christopher D., Kadwell, Brian J.
• Granted Patent: US 7,616,126 B2
• Time in Patent Office: Days
• US Class Current: 340/630
• CPC Class Codes: G08B 17/107 for detecting light-scattering due to smoke
• CPC Class Codes: G08B 17/113 Constructional details
• CPC Class Codes: G08B 3/10 using electric transmission; using electromagnetic transmission

Abstract

The presently disclosed embodiments relate to improved optical particle detection devices and methods of manufacturing.

Claims

1. A particle sensor, comprising:

a light source, an optical transducer and a controller;

said controller in communication with said light source and said optical transducer, said controller is configured to reject substantially all signals except those contributed by said light source.

2. A particle sensor as in claim 1 wherein said controller is further configured to analyze a first output of said optical transducer taken at a first time while said light source is off.

3. A particle sensor as in claim 2 wherein said controller is further configured to analyze a second output of said optical transducer taken at a second time while said light source is on.

4. A particle sensor as in claim 3 wherein the particle sensor is configured to accept modulated power, said controller is further configured to delay said second output by a specific time delay.

5. A particle sensor as in claim 4 wherein said specific time delay is substantially a positive non-zero integer multiple of an input power source period.

6. A particle sensor as in claim 5 wherein said specific time delay is substantially equal to 1 period of an input power source.

7. A particle sensor as in claim 1 further comprising a chimney, an aesthetic cover, a circuit board, and a smoke cage at least partially defined by at least a portion of said chimney, at least a portion of said printed circuit board and at least a portion of said aesthetic cover.

8. A particle sensor as in claim 7 further comprising an alarm threshold.

9. A particle sensor as in claim 7 having a signal to noise ratio of 4:

1 or greater.

10. A particle sensor configured to be mounted to a substantially planar surface, comprising:

an aesthetic cover, a chimney and at least one additional component,

wherein at least a portion of said aesthetic cover, at least a portion of said chimney, and at least a portion of said at least one additional component at least partially defines a smoke cage, wherein airflow through said smoke cage flows substantially perpendicular to the substantially planar mounting surface.

11. A particle sensor as in claim 10 further comprising an alarm threshold.

12. A particle sensor as in claim 10 wherein said chimney comprises an optics block.

13. A particle sensor as in claim 12 wherein said chimney is constructed from a first portion and a second portion.

14. A particle sensor as in claim 13 wherein said first portion and second portion are configured to removably snap together.

15. A particle sensor as in claim 13 wherein said first portion and second portion are permanently attached to each other.

16. A particle sensor as in claim 10 wherein said smoke cage further comprises at least one finished surface.

17. A particle sensor as in claim 16 wherein said at least one finished surface comprises a low luster surface.

18. A particle sensor as in claim 17 wherein said at least one finished surface is substantially black.

19. A particle sensor as in claim 10 having an associated signal to noise ratio of 4:

1 or greater.

20. A particle sensor as in claim 19 having an associated signal to noise ratio of 5:

1 or greater.

21. A particle sensor as in claim 10 further configured such that a least sensitive particle sensor orientation with respect to airflow has an associated sensitivity of at least about 75%.

22. A particle sensor as in claim 10 further configured such that a least sensitive particle sensor orientation with respect to airflow has an associated sensitivity of at least about 90%.

23. A particle sensor as in claim 10 wherein said at least one additional component is a printed circuit board having an area configured to allow airflow therethrough.

24. A particle sensor as in claim 23 further comprising an alarm threshold.

25. A particle sensor as in claim 23 wherein said chimney comprises an optics block.

26. A particle sensor as in claim 25 wherein said chimney is constructed from a first portion and a second portion.

27. A particle sensor as in claim 26 wherein said first portion and second portion are configured to removably snap together.

28. A particle sensor as in claim 26 wherein said first portion and second portion are permanently attached to each other.

29. A particle sensor as in claim 23 wherein said smoke cage further comprises at least one finished surface.

30. A particle sensor as in claim 29 wherein said at least one finished surface comprises a low luster surface.

31. A particle sensor as in claim 30 wherein said at least one finished surface is substantially black.

32. A particle sensor as in claim 23 having an associated signal to noise ratio of 4:

1 or greater.

33. A particle sensor as in claim 32 having an associated signal to noise ratio of 5:

1 or greater.

34. A particle sensor as in claim 23 further configured such that a least sensitive particle sensor orientation with respect to airflow has an associated sensitivity of at least about 75%.

35. A particle sensor as in claim 23 further configured such that a least sensitive particle sensor orientation with respect to airflow has an associated sensitivity of at least about 90%.

36. A particle sensor as in claim 10, further comprising a light source wherein the primary optical axis of light emitted from said light source is substantially parallel to the planar mounting surface.

37. A particle sensor as in claim 36 further comprising an alarm threshold.

38. A particle sensor as in claim 36 wherein said chimney comprises an optics block.

39. A particle sensor as in claim 38 wherein said chimney is constructed from a first portion and a second portion.

40. A particle sensor as in claim 39 wherein said first portion and second portion are configured to removably snap together.

41. A particle sensor as in claim 39 wherein said first portion and second portion are permanently attached to each other.

42. A particle sensor as in claim 36 wherein said smoke cage further comprises at least one finished surface.

43. A particle sensor as in claim 42 wherein said at least one finished surface comprises a low luster surface.

44. A particle sensor as in claim 43 wherein said at least one finished surface is substantially black.

45. A particle sensor as in claim 36 having an associated signal to noise ratio of 4:

1 or greater.

46. A particle sensor as in claim 45 having an associated signal to noise ratio of 5:

1 or greater.

47. A particle sensor as in claim 36 further configured such that a least sensitive particle sensor orientation with respect to airflow has an associated sensitivity of at least about 75%.

48. A particle sensor as in claim 36 further configured such that a least sensitive particle sensor orientation with respect to airflow has an associated sensitivity of at least about 90%.

49. A particle sensor as in claim 10 wherein said aesthetic cover further comprises a removable portion at least partially covering said chimney, said removable portion configured to be removed in a single step.

50. A particle sensor as in claim 49 further comprising an alarm threshold.

51. A particle sensor as in claim 49 wherein said chimney comprises an optics block.

52. A particle sensor as in claim 51 wherein said chimney is constructed from a first portion and a second portion.

53. A particle sensor as in claim 52 wherein said first portion and second portion are configured to removably snap together.

54. A particle sensor as in claim 52 wherein said first portion and second portion are permanently attached to each other.

55. A particle sensor as in claim 49 wherein said smoke cage further comprises at least one finished surface.

56. A particle sensor as in claim 55 wherein said at least one finished surface comprises a low luster surface.

57. A particle sensor as in claim 56 wherein said at least one finished surface is substantially black.

58. A particle sensor as in claim 49 having an associated signal to noise ratio of 4:

1 or greater.

59. A particle sensor as in claim 58 having an associated signal to noise ratio of 5:

1 or greater.

60. A particle sensor as in claim 49 further configured such that a least sensitive particle sensor orientation with respect to airflow has an associated sensitivity of at least about 75%.

61. A particle sensor as in claim 49 further configured such that a least sensitive particle sensor orientation with respect to airflow has an associated sensitivity of at least about 90%.

62. A particle sensor, comprising;

an aesthetic cover having a perimeter, a printed circuit board, a smoke cage, at least two thermal sensors, wherein said thermal sensors are positioned near the perimeter of the aesthetic cover and spaced about 120 degrees apart from each other.

63. A particle sensor as in claim 62 wherein said aesthetic cover is configured to separate the thermal sensors from the area inside the aesthetic cover.

64. A particle sensor as in claim 62 further comprising an alarm threshold.

65. A particle sensor as in claim 64 having a signal to noise ratio of 4:

1 or greater.

66. A particle sensor as in claim 62 further comprising a chimney constructed from a first portion and a second portion.

67. A particle sensor as in claim 62 configured such that a least sensitive particle sensor orientation with respect to airflow has an associated sensitivity of at least about 75%.