Light-responsive vehicle control such as an electro-optic rearview mirror system that is adaptive to vehicle configuration

• US 6,355,920 B1
• Filed: 10/08/1999
• Issued: 03/12/2002
• Est. Priority Date: 10/09/1998
• Status: Expired due to Fees

• Current Assignee: Donnelly Corporation (Magna International Incorporated)
• Original Assignee: Donnelly Corporation (Magna International Incorporated)
• Inventors: Schofield, Kenneth, Schierbeek, Kenneth L.
• Primary Examiner(s): LE, QUE TAN
• Application Number:
  US09/415,346
• Time in Patent Office: 886 Days
• Field of Search: 250/205, 250/207.1, 250/206, 250/214.AL, 250/214.R, 250/216, 359/601, 359/602, 359/603, 359/605, 359/265
• US Class Current: 250/206
• 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 2300/21 Manual control
• CPC Class Codes: B60Q 2300/314 Ambient light
• CPC Class Codes: B60Q 2400/30 Daytime running lights [DRL], e.g. circuits or arrangements therefor
• CPC Class Codes: B60R 1/088 using a cell of electrically changeable optical characteristic, e.g. liquid-crystal or electrochromic mirrors

Abstract

An adaptive light-responsive vehicle control, such as an electro-optic rearview mirror system, and a method of adapting a light-responsive vehicle control to a vehicle which accommodates variations in vehicle configuration includes providing at least one light sensor receiving light passing through the vehicle rear window and monitoring this light sensor, such as for an extended period of time. At least one operating parameter, such as sensitivity, of the light-responsive vehicle control is established as a result of the monitoring. This allows the same light-responsive vehicle control to be used with both tinted and non-tinted rear windows.

Claims

1. A vehicular electro-optic rearview mirror system, comprising:

a vehicle including a passenger compartment having at least a forward viewing forward window, a side viewing window having a side window light transmission value and a rearward viewing rear window having a rear window light transmission value;

an interior rearview mirror assembly in said passenger compartment;

said interior rearview mirror assembly having an interior electro-optic mirror reflective element;

said interior reflective element intercepting passed light that passes through said rearward viewing rear window, said light passing through said rearward viewing rear window being attenuated as a function of said rear window light transmission value, said interior reflective element reflecting at least a portion of said passed light directly to the driver;

at least one exterior rearview mirror assembly outside of said passenger compartment;

said exterior rearview mirror assembly having an exterior electro-optic mirror reflective element;

said exterior reflective element reflecting at least a portion of light incident thereon to the driver via transmission through said side viewing window;

at least one light sensor in said passenger compartment and directed toward said rearward viewing rear window to receive said light passing through said rearward viewing rear window;

a control receiving an input from said at least one light sensor and producing an interior mirror reflectance level signal that establishes a reflectance level of said interior mirror reflective element, said control further producing an exterior mirror reflectance level signal that establishes a reflectance level of said exterior mirror reflective element;

said interior mirror reflectance level signal and said exterior mirror reflectance level signal being a function at least of light sensed by said light sensor and a ratio value; and

wherein said ratio value is established as a function of said rear window light transmission value and said side window light transmission value, said control operating to maintain said interior mirror reflectance level greater than or equal to said exterior mirror reflectance level and wherein said side window light transmission value is greater than said rear window light transmission value.

2. The mirror system in claim 1 wherein said interior and exterior reflectance signals are drive signals establishing respective reflectance levels of said interior and exterior electro-optic reflective elements.

3. The mirror system in claim 2 wherein at least one of said interior electro-optic mirror reflective element and said exterior electro-optic reflective element is an electrochromic mirror.

4. The mirror system in claim 1 wherein said at least one light sensor is facing generally rearwardly of the vehicle.

5. The mirror system in claim 4 including another light sensor sensing light in a different direction than said at least one light sensor wherein said reflectance levels of said interior and exterior reflective elements are functions of light sensed by both of said light sensors.

6. The mirror system in claim 5 wherein said another light sensor is directed generally forwardly of the vehicle toward said forward viewing forward window.

7. The mirror system in claim 1 wherein said vehicle includes headlights and wherein said control further produces a headlight control signal establishing a state of operation of said headlights.

8. The mirror system in claim 7 including another light sensor sensing light in a different direction than said at least one light sensor wherein said state of operation of said headlights is a function of light sensed by both of said light sensors.

9. The mirror system in claim 8 wherein said at least one light sensor is facing generally rearwardly of the vehicle.

10. The mirror system in claim 8 wherein said another light sensor is directed generally forwardly of the vehicle toward said forward viewing forward window.

11. The mirror system in claim 1 wherein said control further determines a sensitivity value, wherein the reflectance levels of said interior and exterior reflective elements are further a function of said sensitivity value.

12. The mirror system in claim 1 wherein said control establishes said ratio value in response to long duration sampling of said at least one light sensor.

13. The mirror system in claim 12 wherein said long duration sampling is on an order of at least one hour of vehicle operation.

14. The mirror system in claim 12 wherein said long duration sampling is on an order of at least ten hours of vehicle operation.

15. The mirror system in claim 12 wherein said long duration sampling occurs when light sensed by said at least one light sensor is greater than a particular light level indicative of daylight operating conditions.

16. The mirror system in claim 15 wherein said particular light level is on an order of 1,000 lux.

17. The mirror system in claim 12 wherein said long duration sampling occurs when the vehicle is initially operated.

18. The mirror system in claim 1 wherein said control comprises digital logic including memory and said ratio value is stored in said memory.

19. The mirror system in claim 1 including a manually adjustable input device for entering said ratio value in said control.

20. The mirror system in claim 19 wherein said input device is operable by a technician to enter said ratio value, said input device not being operable by a driver of the vehicle.

21. The minor system in claim 1 wherein said control further determines at least one of a minimum reflectance level below which said interior electro-optic mirror reflective element will not extend and a maximum reflectance level above which said exterior electro-optic mirror reflective element will not extend, said minimum and maximum reflectance levels being a function of said rear window light transmission value and said side window light transmission value.

22. The mirror system in claim 1 wherein said at least one exterior mirror assembly includes first and second exterior mirror assemblies having respective first and second exterior electro-optic minor reflective elements and wherein said control determines ratio values of reflectance levels among said interior mirror reflective element and said first and second electro-optic exterior mirror reflective elements.

23. The mirror system in claim 22 wherein said control further determines at least one of a minimum value of partial reflectance level below which said interior electro-optic mirror reflective element will not extend and a maximum value of partial reflectance level above which said exterior first and second electro-optic mirror reflective elements will not extend as a function of said rear window light transmission value and said side window light transmission value.

35. The mirror system in claim 19 wherein said at least one exterior mirror assembly includes at least two exterior minor assemblies including first and second said exterior electro-optic mirror reflective elements.

36. The mirror system in claim 35 wherein said control further determines at least one of a minimum value of reflectance level below which said interior mirror reflective element will not extend and a maximum value of reflectance level above which said at least one exterior mirror reflective element will not extend as a function of said long duration sampling.

37. The method of claim 35 including ratio values of reflectance levels among said interior mirror reflective element and said first and second exterior mirror reflective elements.

38. The method of claim 37 wherein said control determines a minimum reflectivity value below which said interior mirror will not extend as a function of said long duration sampling.

24. An adaptive vehicle automatic rearview mirror system, comprising:

a vehicle including a passenger compartment having at least a forward viewing forward window, a side viewing window having a side window light transmission value and a rearward viewing window having a rear window light transmission value, wherein said side window light transmission value is greater than said rear window light transmission value;

an interior rearview mirror assembly and at least one exterior rearview mirror assembly;

said interior rearview minor assembly including an interior electro-optic mirror reflective element in said passenger compartment;

said at least one exterior rearview mirror assembly including an exterior electro-optic mirror reflective element outside of said passenger compartment;

at least two light sensors within the passenger compartment, at least one of said at least two light sensors facing generally rearwardly of the vehicle to receive light passing through the rear window of the vehicle;

a control receiving input from said at least two light sensors and producing an interior mirror reflectance signal establishing a reflectance level of said interior electro-optic mirror reflective element and said control further establishing an exterior mirror reflectance signal establishing a reflectance level of said exterior electro-optic mirror reflective element, said interior mirror reflectance level signal and said exterior mirror reflectance level signal being a function at least of light sensed by said light sensors and a ratio value, wherein said ratio value is established as a function of said rear window light transmission value and said side window light transmission value, wherein said control operates to maintain said interior mirror reflectance level greater than or equal to said exterior mirror reflectance level; and

wherein said control establishes said ratio value as a function of long duration sampling of light sensed by said at least one of said at least two light sensors.

25. The mirror system in claim 24 wherein at least one of said interior electro-optic mirror reflective element and said exterior electro-optic mirror reflective element is an electrochromic mirror.

26. The mirror system in claim 24 wherein said at least one exterior mirror assembly includes a first exterior mirror assembly positioned outside a driver side of the vehicle passenger compartment and a second exterior mirror assembly positioned outside a passenger side of the vehicle passenger compartment.

27. The mirror system in claim 24 wherein said rear window is optionally a tinted window or a non-tinted window.

28. The mirror system in claim 24 wherein said long duration sampling is carried out on the order of at least one hour of vehicle operation.

29. The mirror system in claim 28 wherein said long duration sampling is carried out on the order of at least tens of hours of vehicle operation.

30. The mirror system in claim 24 wherein said long duration sampling is carried out when light sensed by one of said light sensor is greater than a particular light level indicative of daylight operating conditions.

31. The mirror system in claim 30 wherein said particular light level is on the order of 1,000 lux.

32. The mirror system in claim 24 wherein said long duration sampling occurs when the vehicle is initially operated.

33. The mirror system in claim 24 wherein said control comprises digital logic and said ratio value is stored in memory.

34. The mirror system in claim 24 wherein said control further determines a sensitivity value as a function of said long duration sampling and wherein the reflectance levels of said interior and exterior electro-optic mirror reflective elements are further a function of said sensitivity value.

39. A method of controlling a vehicle rearview minor system, comprising:

providing a vehicle having a passenger compartment including at least a forward viewing forward window, a side viewing window having a side window light transmission value and a rearward viewing rear window having a rear window transmission value, wherein said side window light transmission value is greater than said rear window light transmission value, said vehicle rearview mirror system having an interior rearview mirror assembly in said passenger compartment and at least one exterior rearview mirror assembly outside of said passenger compartment, said interior rearview mirror assembly having an interior electro-optic mirror reflective element, said at least one exterior rearview mirror assembly having an exterior electro-optic mirror reflective element, wherein said interior electro-optic mirror reflective element reflects at least a portion of light that passes through the rear window to the driver and wherein said exterior electro-optic minor reflects at least a portion of light incident thereon to the driver via transmission through said side viewing window;

providing at least one first light sensor receiving light passing through said rearward viewing rear window;

monitoring said at least one light sensor for an extended period of time;

establishing a ratio value as a function of said rear window light transmission value and said side window light transmission value, said ratio value being established by said monitoring; and

establishing a reflectance level of said interior electro-optic mirror reflective element and establishing a reflectance level of said exterior electro-optic mirror reflective element at least as a function of light sensed by said at least one light sensor and said ratio value, wherein said reflectance level of said interior electro-optic mirror reflective element is greater than or equal to the reflectance level of said exterior electro-optic mirror reflectance element.

40. The method of claim 39 wherein said at least one operating characteristic is sensitivity.

41. The method of claim 39 wherein said monitoring includes monitoring said at least one light sensor for an order of an hour of vehicle operation.

42. The method of claim 39 wherein said monitoring includes monitoring said at least one light sensor for an order of tens of hours of vehicle operation.

43. The method of claim 39 wherein said monitoring includes monitoring said at least one light sensor when sensed light level is above a particular level.

44. The method of claim 43 wherein said particular level is indicative of daylight condition.

45. The method of claim 44 wherein said particular level is approximately 1,000 lux.

46. The method of claim 39 including at least one additional light sensor receiving light not substantially passing through the vehicle window.

47. The method of claim 46 wherein said at least one additional light sensor receives light passing through the vehicle windshield.

48. The method of claim 39 wherein at least one of said electro-optic mirror reflective elements is an electrochromic reflective element.

49. The method of claim 39 wherein said at least one exterior mirror assembly comprises at least two exterior mirror assemblies.

50. The method of claim 39 wherein said method further includes establishing a sensitivity value and establishing reflectance levels of said interior and exterior electro-optic mirror reflective elements as a function of said sensitivity value.

51. The method of claim 39 wherein the vehicle rearview mirror system includes at least one electrochromic rearview mirror.

52. A vehicular rearview mirror system, comprising:

a vehicle having a passenger compartment, a side viewing window having a side window light transmission value and a rearward viewing rear window having a rear window light transmission value, wherein said side window light transmission value is greater than said rear window light transmission value;

an interior rearview electro-optic minor inside the vehicle passenger compartment and at least one exterior electro-optic mirror outside the vehicle passenger compartment and visible to the diver through said side viewing window;

a forward light sensor capturing ambient light forward of the vehicle and a rearward light sensor capturing passed light that passes through said rearward viewing rear window;

a control receiving an input from said at least one of said light sensors and producing an interior mirror reflectance level signal that establishes a reflectance level of said interior mirror reflective element, said control further producing an exterior mirror reflectance level signal that establishes a reflectance level of said exterior mirror reflective element;

said control operating to maintain said interior mirror reflectance level greater than or equal to said exterior mirror reflectance level at least as a function of the tint condition of the vehicle rear window.

53. The vehicular rearview mirror system in claim 52 wherein said control responds to relative light levels sensed by said forward and rearward sensors to determine a tint condition of the vehicle rear window.

54. The vehicular rearview mirror system in claim 52 wherein said control drives said at least one exterior mirror to a reflectance level that is related to the reflectance level of said interior mirror as a function level of the ratio of light transmissivity of the vehicle'"'"'s rear window to that of the side window lateral of the driver.

55. The vehicular rearview mirror system in claim 52 wherein said control selectively establishes at least one of a minimum value of partial reflectance below which said interior mirror will not color and a maximum value of partial reflectance above which said at least one exterior mirror will not color.

56. The vehicular rearview mirror system in claim 52 wherein said electro-optic mirrors are electrochromic mirrors.

57. The light-responsive control in claim 52 including a manually adjustable input device for entering a parameter related to tint condition of the vehicle rear window in said control.

58. The light-responsive control in claim 57 wherein said input device is operable by a technician to enter said parameter, but not operable by the driver of the vehicle.

59. The vehicle rearview mirror system in claim 52 wherein said control establishes a ratio of the reflectance level of said exterior mirror to said interior mirror.

60. The vehicular rearview mirror system in claim 59 wherein said control establishes at least one of a minimum value of reflectance below which said interior mirror will not color and a maximum value of reflectance above which said exterior mirror will not color.