Light source detection and categorization system for automatic vehicle exterior light control and method of manufacturing

• US 6,774,988 B2
• Filed: 07/30/2002
• Issued: 08/10/2004
• Est. Priority Date: 07/30/2002
• Status: Expired due to Term

• Current Assignee: Gentex Corporation
• Original Assignee: Gentex Corporation
• Inventors: Bush, Gregory S., Tuttle, Darin D., Stam, Joseph S., Bechtel, Jon H., Ockerse, Harold C., Reese, Spencer D.
• Primary Examiner(s): Rosenberger, Richard A.
• Assistant Examiner(s): Barth, Vincent P.
• Application Number:
  US10/208,142
• Publication Number:
  US 20040021853A1
• Time in Patent Office: 742 Days
• Field of Search: 356/121, 356/122, 356/217-234, 356/151--15, 356/152--15, 250/208.1, 250/208.2, 250/214.AL, 250/214.C, 382/104, 340/468, 340/469, 340/435, 340/933, 340/942, 362/465, 362/466, 315/82, 315/77
• US Class Current: 356/218
• CPC Class Codes: B60Q 1/1423 Automatic dimming circuits, i.e. switching between high beam and low beam due to change of ambient light or light level in road traffic
• CPC Class Codes: B60Q 2300/112 Vehicle speed
• CPC Class Codes: B60Q 2300/314 Ambient light
• CPC Class Codes: B60Q 2300/41 preceding vehicle
• CPC Class Codes: B60Q 2300/42 oncoming vehicle
• CPC Class Codes: B60Q 2300/45 Special conditions, e.g. pedestrians, road signs or potential dangers
• CPC Class Codes: G01J 1/04 Optical or mechanical part supplementary adjustable parts
• CPC Class Codes: G01J 1/0403 Mechanical elements; Supports for optical elements; Scanning arrangements
• CPC Class Codes: G01J 1/32 adapted for automatic variation of the measured or reference value regulation of light intensity G05D25/00
• CPC Class Codes: G01J 1/42 using electric radiation detectors optical or mechanical part G01J1/04; by comparison with a reference light or electric value G01J1/10
• CPC Class Codes: G06V 10/143 Sensing or illuminating at different wavelengths
• CPC Class Codes: G06V 20/584 of vehicle lights or traffic lights

Abstract

The optical system of the present invention includes a lens system assembly, a spectral filter material and a pixel array configured such that small, distant, light sources can be reliably detected. The optical system of the present invention provides accurate measurement of the brightness of the detected light sources and identification of the peak wavelength and dominant wavelength of the detected light sources. Use of the optical system of the present invention provides the ability to distinguish headlights of oncoming vehicles and taillights of leading vehicles from one another, as well as, from other light sources.

Claims

1. A light source detection and classification system, for use in an automatic vehicle exterior light control system, capable of detecting small, distant, light sources, comprising:

at least one optical system with a spatial frequency cutoff; and

at least one pixel array with a Nyquist frequency limit, wherein said spatial frequency cutoff is less than, or equal, to said Nyquist frequency limit.

2. A light source detection and classification system as in claim 1 wherein said at least one optical system having a lens system assembly that projects light rays emitted by an 8 to 20 centimeter diameter, red, taillight assembly, located between 100 and 250 meters away from said lens system assembly, onto a pixel array such that said projected light rays substantially spans at least one pixel pitch.

3. A light source detection and classification system as in claim 2, wherein said projected light rays comprise an associated brightness and said at least one optical system provides for accurate measurement of said brightness.

4. A light source detection and classification system as in claim 2, wherein said projected light rays comprise an associated peak wavelength and said at least one optical system provides for accurate identification of said peak wavelength.

5. A light source detection and classification system as in claim 2, wherein said projected light rays comprise an associated dominant wavelength and said at least one optical system provides for accurate identification of said dominant wavelength.

6. A light source detection and classification system as in claim 1, wherein said light sources comprise an associated brightness and said light source detection and classification system provides for accurate measurement of said brightness.

7. A light source detection and classification system as in claim 1, wherein said light sources comprise an associated peak wavelength and said light source detection and classification system provides for accurate identification of said peak wavelength.

8. A light source detection and classification system as in claim 1, wherein said light sources comprise an associated dominant wavelength and said light source detection and classification system provides for accurate identification of said dominant wavelength.

9. A light source detection and classification system as in claim 1, further comprising at least one spectral filter material disposed between said light sources and said pixel array.

10. A light source detection and classification system as in claim 9 capable of distinguishing headlights of oncoming vehicles from taillights of leading vehicles.

11. A light source detection and classification system as in claim 9 capable of distinguishing headlights of oncoming vehicles from other light sources.

12. A light source detection and classification system as in claim 9 capable of distinguishing taillights of leading vehicles from other light sources.

13. A light source detection and classification system as in claim 9, wherein said at least one spectral filter material is a pigment.

14. A light source detection and classification system as in claim 13, wherein said pigment is inorganic.

15. A light source detection and classification system as in claim 9, wherein said at least one spectral filter material is placed on said pixel array.

16. A light source detection and classification system as in claim 9, further comprising an encapsulate block, wherein said at least one spectral filter material is incorporated into said encapsulate block.

17. A light source detection and classification system as in claim 9, further comprising an encapsulate block, wherein said at least one spectral filter material is placed on said encapsulate block.

18. A light source detection and classification system as in claim 9, further comprising an encapsulate block and a lens system assembly, wherein said lens system assembly is attached to said encapsulate block and said at least one spectral filter material is disposed between said encapsulate block and said lens system assembly.

19. A light source detection and classification system as in claim 9, further comprising a lens system assembly, wherein said at least one spectral filter material is incorporated into said lens system assembly.

20. A light source detection and classification system as in claim 9, further comprising a lens system assembly, wherein said at least one spectral filter material is placed on said lens system assembly.

21. A light source detection and classification system as in claim 1, further comprising a photochromic spectral filter disposed between said light sources and said pixel array.

22. A light source detection and classification system as in claim 1, further comprising an electrochromic spectral filter disposed between said light sources and said pixel array.

23. A light source detection and classification system as in claim 1, further comprising an encapsulate block and a lens system assembly, said lens system assembly is attached to said encapsulate block.

24. A light source detection and classification system as in claim 23, further comprising a printed circuit board, said pixel array is attached to said printed circuit board and said encapsulate block is molded over said pixel array and attached to said printed circuit board.

25. A light source detection and classification system as in claim 23, wherein said lens system is attached to said encapsulate block with a UV curable adhesive.

26. A light source detection and classification system as in claim 1, further comprising an aperture stop.

27. A light source detection and classification system as in claim 1, further comprising a far field baffle.

28. A light source detection and classification system as in claim 1 further comprising:

at least one pigment spectral filter material disposed between light sources to be detected and said at least one pixel array.

29. A light source detection and classification system as in claim 28, wherein said at least one pigment spectral filter material is red.

30. A light source detection and classification system as in claim 29, wherein said pigment spectral filter material has a fifty-percent transmission point between 580 and 620 nanometers.

31. A light source detection and classification system as in claim 30, wherein said pigment spectral filter material has a fifty-percent transmission point at 605 nanometers.

32. A light source detection and classification system as in claim 28, wherein said at least one pigment spectral filter material is infrared.

33. A light source detection and classification system as in claim 29, wherein said pigment spectral filter material has a fifty-percent transmission point between 630 and 780 nanometers.

34. A light source detection and classification system as in claim 30, wherein said pigment spectral filter material has a fifty-percent transmission point between 640 and 700 nanometers.

35. A light source detection and classification system as in claim 30, wherein said pigment spectral filter material has a fifty-percent transmission point at 680 nanometers.

36. A light source detection and classification system as in claim 30, wherein said pigment spectral filter material has a fifty-percent transmission point at 660 nanometers.

37. A light source detection and classification system as in claim 28, wherein pixels of one contiguous half of said pixel array are filtered with said spectral filter material.

38. A light source detection and classification system as in claim 28, wherein individual pixels of said pixel array are filtered with said spectral filter material such that alternating stripes of filtered and unfiltered pixels are defined.

39. A light source detection and classification system as in claim 28, wherein individual pixels of said pixel array are filtered with said spectral filter material such that a checkerboard pattern of filtered and unfiltered pixels is defined.

40. A light source detection and classification system as in claim 28, wherein a red spectral filter material, a green spectral filter material and a blue spectral filter material are disposed between said light sources to be detected and said pixel array.

41. A light source detection and classification system as in claim 40, wherein twice as many pixels of said pixel array are red filtered as compared to the number of pixels either green or blue filtered.

42. A light source detection and classification system as in claim 40, wherein individual pixels of said pixel array are filtered such that a Bayer pattern is defined.

43. A light source detection and classification system as in claim 1 further comprising:

a red spectral filter material disposed between reflected light rays to be detected and said at least one pixel array.

44. A light source detection and classification system as in claim 43, further comprising an infrared filter material disposed between reflected light rays to be detected and the light ray detection and classification system.

45. A light source detection and classification system as in claim 43, further comprising headlights having high color temperature.

46. A light source detection and classification system as in claim 43, wherein said color temperature is greater than 3500 Kelvin.

47. A light source detection and classification system as in claim 43, wherein said color temperature is 3700 Kelvin.

48. A light source detection and classification system as in claim 46, wherein said color temperature is greater than 4500 Kelvin.

49. A light source detection and classification system as in claim 43, wherein said at least one headlight is high intensity discharge.

50. A light source detection and classification system as in claim 43, wherein said at least one headlight is at least one light emitting diode.

51. A light source detection and classification system as in claim 43, wherein said at least one headlight is halogen-infrared.

52. A light source detection and classification system as in claim 43, wherein said at least one headlight is halogen.

53. A light source detection and classification system as in claim 43, wherein said at least one headlight is blue enhanced halogen.

54. A light source detection and classification system as in claim 43, wherein pixels of one contiguous half of said pixel array are filtered with said spectral filter material.

55. A light source detection and classification system as in claim 43, wherein individual pixels of said pixel array are filtered with said spectral filter material such that alternating stripes of filtered and unfiltered pixels are defined.

56. A light source detection and classification system as in claim 43, wherein individual pixels of said pixel array are filtered with said spectral filter material such that a checkerboard pattern of filtered and unfiltered pixels is defined.

57. A light source detection and classification system as in claim 43, further comprising a green spectral filter material and a blue spectral filter material disposed between said light sources to be detected and said pixel array.

58. A light source detection and classification system as in claim 57, wherein twice as many pixels of said pixel array are red filtered as compared to the number of pixels either green or blue filtered.

59. A light source detection and classification system as in claim 57, wherein individual pixels of said pixel array are filtered such that a Bayer pattern is defined.

60. An optical system, for use in an automatic vehicle exterior light control, capable of detecting small, distant, light sources, comprising:

at least one pixel array having a plurality of pixels; and

a modulation transfer function that first drops to e<sup>−

1</sup> at a spatial frequency that is less than, or equal to, the reciprocal of the minimum center-to-center distance between any two adjacent pixels.

61. An optical system as in claim 60, wherein said distant light source emits light rays that comprise an associated brightness and said optical system provides for accurate measurement of said brightness.

62. An optical system as in claim 60, wherein said distant light source emits light rays that comprise an associated peak wavelength and said optical system provides for accurate identification of said peak wavelength.

63. An optical system as in claim 60, wherein said distant light source emits light rays that comprise an associated dominant wavelength and said optical system provides for accurate identification of said dominant wavelength.

64. An optical system as in claim 60, further comprising at least one spectral filter material disposed between said light sources to be detected and said pixel array.

65. An optical system as in claim 64, wherein said at least one spectral filter material is a pigment.

66. An optical system as in claim 65, wherein said pigment is inorganic.

67. An optical system as in claim 60, further comprising a photochromic spectral filter disposed between said light sources to be detected and said pixel array.

68. An optical system as in claim 60, further comprising an electrochromic spectral filter disposed between said light sources to be detected and said pixel array.

69. An optical system as in claim 60, further comprising an encapsulate block and a lens system assembly, said lens system assembly is attached to said encapsulate block.

70. An optical system as in claim 69, further comprising a printed circuit board, said encapsulate block is attached to said printed circuit board.

71. An optical system as in claim 70, wherein said lens system assembly is attached to said encapsulate block with a UV curable adhesive.

72. An optical system as in claim 60, further comprising an aperture stop.

73. An optical system as in claim 69, further comprising a far field baffle.

94. An optical system as in claim 60 further comprising:

a lens system that projects a distant, point source, of light onto a pixel array such that said projected distant point source of light substantially spans at least one pixel pitch.

95. An optical system as in claim 94, wherein said distant, point source, of light is in the range of 5 to 15 centimeters in diameter and located between 100 and 250 meters from said optical system.

96. An optical system as in claim 94, wherein said projected distant, point source, of light substantially covers at least two pixel pitches.

97. An optical system as in claim 94, wherein said distant, point source, of light is monochromatic.

98. An optical system as in claim 60 further comprising:

a dual lens system assembly for projecting a field of view onto a pixel array such that a first image of said field of view is formed on a first portion of said pixel array and a second image of said field of view is formed on a second portion of said pixel array; and

at least one pigment spectral filter material disposed between said field of view and said pixel array.

99. An optical system as in claim 98, wherein said spectral filter material is disposed such that said first image is filtered and said second image is unfiltered.

100. An optical system as in claim 98, further comprising an infrared spectral filter material disposed between said field of view and said pixel array.

101. An optical system as in claim 98, wherein each lens system of said dual lens system assembly is symmetrically truncated.

102. An optical system as in claim 60 further comprising:

a dual lens system assembly for projecting a field of view onto a pixel array such that a first image of said field of view is formed on a first portion of said pixel array and a second image of said field of view is formed on a second portion of said pixel array, wherein each lens system of said dual lens system assembly is symmetrically truncated.

103. An optical system as in claim 60 further comprising:

a pixel array attached to a printed circuit board; and

an encapsulate block molded over said pixel array and attached to said printed circuit board.

104. An optical system as in claim 103, wherein said encapsulate block is precision transfer molded.

105. An optical system as in claim 103, further comprising a lens system assembly attached to said encapsulate block.

106. An optical system as in claim 105, wherein said lens system assembly is attached to said encapsulate block with UV curable adhesive.

107. An optical system as in claim 105, wherein said encapsulate block comprises registration features and said lens system assembly comprises mating features, said lens system assembly is attached to said encapsulate block with said mating features being received by said registration features.

108. An optical system as in claim 103, further comprising micro lenses on each pixel within said pixel array.

109. An optical system as in claim 103, further comprising a light ray scattering film disposed proximate said pixel array.

110. An optical system as in claim 103, wherein said encapsulate block comprises an optical surface and functions as a lens system assembly.

111. An optical system as in claim 103, further comprising a plurality of cascaded lens systems, said encapsulate block having mating features and each of said lens systems having registration features and mating features for interconnection of said lens systems and said encapsulate block.

112. An optical system as in claim 103, further comprising a variable focal length lens system assembly.

113. An optical system as in claim 103, further comprising a variable focus lens system.

114. An optical system as in claim 103, further comprising a lens system assembly that provides achromatic aberration correction.

74. An optical system, for use in an automatic vehicle exterior light control, capable of detecting small, narrow spectral band, distant light sources, comprising:

at least one pixel array having a plurality of pixels, at least a portion of said pixels being spectral filtered; and

a polychromatic modulation transfer function that first drops to e<sup>−

1</sup> at a spatial frequency that is less than, or equal top the reciprocal of the minimum center-to-center distance between any two similarly filtered pixels.

75. An optical system as in claim 74, wherein said distant light source emits light rays that comprise an associated brightness and said optical system provides for accurate measurement of said brightness.

76. An optical system as in claim 74, wherein said distant light source emits light rays that comprise an associated peak wavelength and said optical system provides for accurate identification of said peak wavelength.

77. An optical system as in claim 74, wherein said distant light source emits light rays that comprise an associated dominant wavelength and said optical system provides for accurate identification of said dominant wavelength.

78. An optical system as in claim 74, further comprising at least one spectral filter material disposed between said light sources and said pixel array.

79. An optical system as in claim 78, wherein pixels of one contiguous half of said pixel array are filtered with said spectral filter material.

80. An optical system as in claim 78, wherein individual pixels of said pixel array are filtered with said spectral filter material such that alternating stripes of filtered and unfiltered pixels are defined.

81. An optical system as in claim 78, wherein individual pixels of said pixel array are filtered with said spectral filter material such that a checkerboard pattern of filtered and unfiltered pixels is defined.

82. An optical system as in claim 78, wherein a red spectral filter material, a green spectral filter material and a blue spectral filter material are disposed between said light sources to be detected and said pixel array.

83. An optical system as in claim 81, wherein twice as many pixels of said pixel array are red filtered as compared to the number of pixels either green or blue filtered.

84. An optical system as in claim 81, wherein individual pixels of said pixel array are filtered such that a Bayer pattern is defined.

85. An optical system as in claim 74, wherein said at least one spectral filter material is a pigment.

86. An optical system as in claim 74, wherein said pigment is inorganic.

87. An optical system as in claim 74, further comprising a photochromic spectral filter disposed between said light sources to be detected and said pixel array.

88. An optical system as in claim 74, further comprising an electrochromic spectral filter disposed between said light sources to be detected and said pixel array.

89. An optical system as in claim 74, further comprising an encapsulate block and a lens system assembly, said lens system assembly is attached to said encapsulate block.

90. An optical system as in claim 89, further comprising a printed circuit board, said pixel array is attached to said printed circuit board and said encapsulate block is molded over said pixel array and is attached to said printed circuit board.

91. An optical system as in claim 90, wherein said lens system assembly is attached to said encapsulate block with a UV curable adhesive.

92. An optical system as in claim 74, further comprising an aperture stop.

93. An optical system as in claim 74, further comprising a far field baffle.